Conductive resin composition for watch casings and watch using the same

Abstract

To provide a conductive resin composition for watch exteriors that can form a suitable cured material for providing electrical conductivity in the gap between the watch bezel and the case. [Solution] The conductive resin composition for watch exteriors of the present invention comprises an epoxy resin having a viscosity of 50P or less at 25°C, comprising at least one selected from the group consisting of bisphenol A type epoxy resin and bisphenol F type epoxy resin; a curing agent comprising at least one selected from the group consisting of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin and 1,18-(hydrazinocarbonyl)-7,11-octadecadiene; flaky silver particles; fumed silica; and an alcohol having 2 to 4 carbon atoms.

Description

Technical Field

[0001] The present invention relates to a conductive resin composition for a watch exterior and a watch using the same.

Background Art

[0002] A wristwatch may have a structure in which a resin packing is used and a bezel and a case are press-fitted and assembled. In this structure, when the bezel and the case are press-fitted and assembled, the bezel floats upward due to the repulsive force of the resin packing, and a slight gap is formed between the bezel and the case. In a wristwatch having this structure, when static electricity is generated near the bezel, the bezel and the case are not in contact and do not conduct electricity, so the static electricity cannot be released to the outside, and there is a possibility that the electronic components of the movement may malfunction due to the static electricity. As a result, it may have an adverse effect on the watch, such as causing the watch to slow down.

[0003] By the way, Patent Document 1 describes a heat-resistant conductive adhesive for adhering an IC chip to an insulating substrate or an electrode, which is composed of flaky silver powder, spherical silver powder, polyimide, and a vehicle. Further, Patent Document 2 describes a conductive paste composed of (A) flattened silver powder or a mixture of flattened silver powder and flattened silver-plated copper powder, (B) a thermoplastic resin having a penetration amount of 30 μm or less up to 100 °C measured using a thermomechanical measuring device, and (C) an organic solvent. Further, Patent Document 3 describes a conductive paste composition characterized by comprising a phenol resin, a melamine resin, conductive powder, a solvent, and sorbitol. Further, Patent Document 4 describes a conductive adhesive composed of a thermosetting compound and a conductive filler, and the thermosetting compound contains at least a hydrazide compound.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

[0005] To dissipate static electricity to the outside, it is conceivable to place a cured conductive resin composition in the gap between the bezel and the case to create conductivity between the bezel and the case. However, the conductive resin compositions described in Patent Documents 1 to 4 cannot form a suitable cured material for creating conductivity between the bezel and the case. Therefore, it is not possible to prevent adverse effects on the movement when static electricity is generated near the bezel.

[0006] Therefore, the object of the present invention is to provide a conductive resin composition for watch exteriors that can form a suitable cured product for providing electrical conductivity in the gap between the watch bezel and the case. [Means for solving the problem]

[0007] The conductive resin composition for watch exteriors of the present invention comprises an epoxy resin having a viscosity of 50P or less at 25°C and comprising at least one selected from the group consisting of bisphenol A type epoxy resin and bisphenol F type epoxy resin; a curing agent comprising at least one selected from the group consisting of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin and 1,18-(hydrazinocarbonyl)-7,11-octadecadiene; flake-shaped silver particles; fumed silica; and an alcohol having 2 to 4 carbon atoms. When the total amount of the epoxy resin and curing agent is 100 parts by mass, the composition contains 450 parts by mass or more of the silver particles and 2% by mass or more but less than 5% by mass of the alcohol. [Effects of the Invention]

[0008] The conductive resin composition for watch exteriors of the present invention allows for the formation of a suitable cured product that provides conductivity in the gap between the watch bezel and the case. Therefore, it is possible to prevent adverse effects on the movement when static electricity is generated near the bezel. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a diagram illustrating a clock according to an embodiment. [Figure 2] Figure 2 is a diagram illustrating the method for manufacturing a clock according to an embodiment. [Modes for carrying out the invention]

[0010] Embodiments for carrying out the present invention will be described in detail below. The present invention is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by those skilled in the art, and those that are substantially the same. In addition, the components described below can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the present invention.

[0011] <Conductive resin composition for watch exteriors> The conductive resin composition for watch cases according to this embodiment combines a specific epoxy resin with a specific curing agent. Using this conductive resin composition, a cured product with suitable hardness can be formed in the gap when the bezel and case are press-fitted together using a resin gasket, thereby ensuring electrical conductivity between the bezel and the case. Furthermore, in the manufacture of watches, the case, after the bezel has been press-fitted and the cured product has formed, may undergo a solvent cleaning process before being assembled with other parts. Because the cured product has high solvent resistance, it does not change even after the cleaning process, and suitable electrical conductivity can be achieved between the bezel and the case. Additionally, the conductive resin composition for watch cases according to this embodiment contains specific silver particles, which allows for suitable electrical conductivity between the bezel and the case by forming the cured product. Furthermore, because the conductive resin composition for watch cases according to this embodiment contains fumed silica, a uniform cured product can be formed. This is also preferable from the viewpoint of electrical conductivity between the bezel and the case. Moreover, the conductive resin composition for watch cases according to this embodiment contains a specific amount of a specific alcohol. Therefore, the above-mentioned conductive resin composition for watch exteriors can be cured at temperatures below the heat resistance temperature of the bezel and case, which are components of the watch exterior (specifically, below 80°C). Furthermore, it does not violate regulations on the emission of volatile organic compounds (VOCs) and is environmentally friendly.

[0012] Incidentally, the conductive resin compositions described in Patent Documents 1, 3, and 4 are cured at temperatures significantly exceeding 80°C and therefore cannot be used for watch exterior parts. Furthermore, the cured product using the conductive resin composition described in Patent Document 2 cannot achieve a suitable hardness for electrical conductivity between the bezel and the case in the aforementioned gap.

[0013] The epoxy resin, which is the main component, is liquid at 25°C and has a viscosity of 50P or less at 25°C. Using this epoxy resin, a conductive resin composition for watch cases with a desirable viscosity range can be obtained. In other words, the conductive resin composition for watch cases can wrap around narrow areas where conductivity is to be established, and good conductivity can be achieved after curing. Specifically, when the conductive resin composition for watch cases is applied to the case, and when the bezel is pressed in and the conductive resin composition for watch cases is cured, the conductive resin composition for watch cases is prevented from flowing out from the application site and can maintain a desirable shape. Furthermore, a cured product with a suitable hardness can be formed to establish conductivity between the bezel and the case in the gap.

[0014] The epoxy resin described above includes at least one selected from the group consisting of bisphenol A type epoxy resin and bisphenol F type epoxy resin. The epoxy resin may be used alone or in combination of two or more types. Specifically, the epoxy resin may be a mixture of a bisphenol A type epoxy resin having a viscosity of 35P to 150P at 25°C and a bisphenol F type epoxy resin having a viscosity of 5P to 50P, preferably 10P to 50P, at 25°C. The resulting mixture should be adjusted so that its viscosity at 25°C is 50P or less. Since the viscosity of the conductive resin composition for watch cases is usually adjusted with the main component, using a low-viscosity bisphenol F type epoxy resin together with the bisphenol A type epoxy resin has the advantage of making viscosity adjustment easier. Furthermore, using a bisphenol A type epoxy resin has the advantage of forming a cured product with excellent oil resistance and water resistance.

[0015] The above-mentioned curing agent contains at least one selected from the group consisting of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin (the following formula (1), CAS number: 88122-32-1, melting point: 118-124 °C) and 1,18-(hydrazinocarbonyl)-7,11-octadecadiene (1,18-(hydrazinocarbonyl)-7,11-octadecadiene, the following formula (2), CAS number: 79240-70-3, melting point: 154-168 °C). The above-mentioned curing agent may be used alone or in combination of two kinds. When the above-mentioned curing agent is used, a cured product having a suitable hardness can be formed because the bezel and the body are electrically connected. Furthermore, since the curing agent is solid at room temperature, the above-mentioned conductive resin composition for watch exterior can be stored at room temperature and has the advantage of excellent handling property.

[0016]

Chemical formula

[0017] Also, the above-mentioned curing agent preferably has a particle size range of 30 μm or less (specifically, more than 0 μm and 30 μm or less). Furthermore, it is more preferable to perform pulverization by a jet mill so that the particle size range is 15 μm or less (specifically, more than 0 μm and 15 μm or less), and the average particle size D50 is 1.5 μm or more and 5 μm or less. The average particle size D50 also refers to the median diameter (number median diameter), and refers to D50 measured by a laser diffraction particle size distribution measuring device. When the particle size range and the average particle size D50 are within the above ranges, separation of the curing agent in the above-mentioned conductive resin composition for watch exterior can be further suppressed. Also, during curing, separation of the curing agent can be further suppressed, and a cured product cured more uniformly microscopically can be obtained.

[0018] From the viewpoint of forming a cured product having a suitable hardness, the conductive resin composition for watch exterior according to the embodiment preferably contains the above epoxy resin in an amount of 55 parts by mass or more and 75 parts by mass or less, and the above curing agent in an amount of 25 parts by mass or more and 45 parts by mass or less when the total of the above epoxy resin and the above curing agent is 100 parts by mass.

[0019] The above silver particles are flaky. Preferably, the 50% average particle size of the above silver particles is 7.0 μm or more and 9.5 μm or less, and the tap density is 4.5 g / cm³. 3 More than 5.3g / cm 3 The following is more preferable. Note that the 50% average particle size is also called the median diameter (number median diameter) and refers to D50 measured by a laser diffraction particle size distribution analyzer. The tap density is a value measured in accordance with JIS Z 2512:2012 Metal powder - Tap density measurement method. With the hardened material containing the above silver particles, the bezel and the body can be suitably connected in the above gap. In particular, if the particles are in a flaky shape, paths can be formed more suitably in the hardened material.

[0020] The conductive resin composition for watch exteriors according to the embodiment contains 450 parts by mass or more, preferably 500 parts by mass or more and 530 parts by mass or less, of the silver particles when the total amount of the epoxy resin and the curing agent is 100 parts by mass. A cured product containing the above amount of silver particles allows for more favorable electrical conductivity between the bezel and the case in the gap. Including the silver particles within the above range also has the advantage of making it easier to adhere the conductive resin composition for watch exteriors to the case.

[0021] The fumed silica described above can be considered a curing aid. Because the fumed silica is used, the conductive resin composition for watch cases can be cured uniformly even at a microscopic level. This is because, in the conductive resin composition for watch cases, the fumed silica suppresses the separation of the main component, the curing agent, and the silver particles during curing. In other words, if the main component is liquid and the curing agent and silver particles are solid, they may separate during heat curing due to differences in specific gravity, resulting in a microscopically non-uniform curing reaction. In contrast, because the conductive resin composition for watch cases contains fumed silica, thixotropy is created in the conductive resin composition for watch cases. As a result, even if the liquid component (main component) in the conductive resin composition for watch cases becomes less viscous due to heating, the solid components (curing agent and silver particles) are less likely to migrate and separate, thus preventing a non-uniform curing reaction. Thus, since the above-mentioned conductive resin composition for watch exteriors hardens uniformly even at a microscopic level, the hardened material can suitably create electrical conductivity between the bezel and the case in the gap.

[0022] The above-mentioned fumed silica is produced, for example, by flame hydrolysis of a halogenated silane such as chlorosilane. Fumed silica may also be hydrophobized fumed silica obtained by reacting the OH groups present on the surface with an organosilicon compound such as dimethyldichlorosilane. It is preferable that the average primary particle diameter of the fumed silica is 500 nm or less. The average primary particle diameter can be determined from a transmission electron microscope image. When the average primary particle diameter is within the above range, the separation of the main component, the curing agent, and the silver particles is further suppressed during curing, and a more uniformly cured product is obtained even at a microscopic level.

[0023] From the viewpoint of forming a uniformly cured product, the conductive resin composition for watch casings according to the embodiment preferably contains fumed silica in an amount of 0.3 parts by mass or more and 1.0 part by mass or less, when the total amount of epoxy resin and curing agent is 100 parts by mass.

[0024] The alcohol described above has 2 to 4 carbon atoms, preferably 2 to 3. Thus, a solvent having hydroxyl groups is used, with a viscosity of 3.5 mPa·S or less at 20°C and a boiling point of 120°C or less, preferably 100°C or less, more preferably 90°C or less. Specifically, examples of the alcohol include ethanol, ethylene glycol, 1-propanol, 2-propanol (isopropyl alcohol, IPA), 1-butanol, 2-butanol, and tert-butyl alcohol. The alcohol may be used individually or in combination of two or more. When the alcohol is used, the conductive resin composition for the watch exterior can be cured at a temperature below the heat resistance temperature of the bezel and case (specifically, below 80°C). This is thought to be because the alcohol activates the epoxy resin, making it more reactive with the curing agent even below the melting point of the curing agent. Furthermore, since the alcohol can volatilize at, for example, 80°C, it has the advantage of not remaining in the cured product.

[0025] The conductive resin composition for watch exteriors according to the embodiment contains the above-mentioned alcohol in an amount of 2% by mass or more and less than 5% by mass, preferably 3% by mass or more and less than 5% by mass. When the above amount is included, the conductive resin composition for watch exteriors can be suitably cured at or below the heat resistance temperature of the bezel and case (specifically, 80°C or below). Furthermore, it can be suitably cured in, for example, 8 hours or less (preferably 6 hours or less, more preferably 1 hour or more and 2 hours or less). Moreover, it is preferable in that it does not violate regulations on the emission of volatile organic compounds (VOCs).

[0026] The conductive resin composition for watch cases according to the embodiment preferably has a viscosity of 10P or more and 50P or less at 25°C. The conductive resin composition for watch cases according to the embodiment is obtained by appropriately mixing the above-mentioned components. For this reason, the viscosity of the conductive resin composition for watch cases is usually within the above range. When the viscosity is within the above range, when the conductive resin composition for watch cases is attached to the case, and when the bezel is pressed in and the conductive resin composition for watch cases is cured, the conductive resin composition for watch cases does not leak out from the attachment point and can maintain a desirable shape. Specifically, the conductive resin composition for watch cases can be prepared by measuring out the main agent and the curing agent, adding fumed silica and silver particles, and then adding alcohol.

[0027] <Clock> Figure 1 is a diagram illustrating a watch according to an embodiment. Specifically, Figure 1 shows a portion of a cross-sectional view of the watch according to the embodiment, from the 12 o'clock to the 6 o'clock position. The watch according to the embodiment (wristwatch) includes a cured product A of the conductive resin composition for watch exteriors described above. In Figure 1, the watch according to the embodiment includes a crystal 2, a bezel 4, a case 6, a resin packing 8, a dial 10, a movement 12, and a case back 14 (the movement 12 is composed of multiple elements such as a substrate and electronic components, and is shown by a dashed line in the figure). The crystal 2 is fitted into the bezel 4, and the dial 10 and the movement 12 are housed in the case 6 by the case back 14. The watch according to the embodiment has a structure in which the bezel 4 and the case 6 are press-fitted together using the resin packing 8. When the bezel 4 and the case 6 are press-fitted together, the bezel 4 floats upward due to the repulsive force of the resin packing 8, and a small gap B is created between the bezel 4 and the case 6. In the watch according to this embodiment, a cured product A of the conductive resin composition for watch exteriors is formed in the gap B, and electrical conductivity is established between the bezel 4 and the case 6 via the cured product A. Therefore, when static electricity is generated near the bezel 4, the static electricity flows from the bezel 4 to the case 6 and then to the case back 14 via the cured product A. In this way, in the watch according to this embodiment, static electricity does not flow to the movement 12, so the movement 12 is not adversely affected. Specifically, malfunctions such as the watch running slow do not occur.

[0028] A watch according to this embodiment can be manufactured, for example, as described below. Figure 2 is a diagram illustrating the manufacturing method of a watch according to this embodiment. As shown in Figure 2, the above-mentioned conductive resin composition for watch exteriors (resin composition C) is applied to the case 6, for example, at the 12 o'clock position and the 6 o'clock position when the dial 10 is housed. Next, a resin packing 8 is placed on the case 6 and the bezel 4 is press-fitted. The resin composition C may be applied to two other locations besides the 12 o'clock and 6 o'clock positions, or to one or three or more locations. Next, the case 6 with the bezel 4 press-fitted is heated to 80°C or less (preferably 50°C or more and 80°C or less) for, for example, 8 hours or less (preferably 6 hours or less, more preferably 1 hour or more and 2 hours) to cure the resin composition C and form a cured product A. Using the case 6 with the bezel 4 press-fitted and the cured product A formed, the watch according to this embodiment is assembled with other parts by a known method. Here, as described above, the case 6 into which the bezel 4 has been press-fitted and hardened material A has formed may be cleaned with a solvent before being assembled with other parts. Since hardened material A has high solvent resistance, it does not change even after the cleaning process, and electrical conductivity can be suitably established between the bezel 4 and the case 6. Electrical conductivity can be confirmed using an electrical conductivity testing device for watch exteriors.

[0029] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples. [Examples] [Components used in the examples and comparative examples] <Main component> Bisphenol F type epoxy resin (liquid at room temperature, viscosity at 25°C between 30P and 45P) (referred to as F type in Table 1); Bisphenol A type epoxy resin (liquid at room temperature, viscosity at 25°C between 120P and 150P) (referred to as A type in Table 1). <Curing Agent> 1,3-Bis(hydrazinocarboethyl)-5-isopropylhydantoin (Grinded using a jet mill to achieve a particle size range of 15 μm or less, with an average particle size D50 of 1.5 μm to 5 μm) (Indicated as VDH in Table 1); 1,18-(hydrazinocarbonyl)-7,11-octadecadiene (Grinded using a jet mill to achieve a particle size range of 15 μm or less, with an average particle size D50 of 1.5 μm to 5 μm) (Indicated as UDH in Table 1). <Silver particles> 50% average particle size is between 7.0 μm and 9.5 μm, and tap density is 4.5 g / cm³ 3 More than 5.3g / cm 3 The following are flaky silver particles. <Fumed Silica> Fumed silica with an average primary particle diameter of 500 nm or less. <Alcohols> Ethanol; Ethylene glycol; 1-Propanol; 2-Propanol (Isopropyl alcohol, IPA) (referred to as IPA in Table 1); 1-Butanol; 2-Butanol; Tert-Butyl alcohol

[0030] [Example 1-1] At room temperature, 74 parts by mass of bisphenol F type epoxy resin was weighed out as the main component, and 26 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of the main component and curing agent, and then 500 parts by mass of silver particles were added and mixed. Then, ethanol was added to the resulting mixture and mixed to prepare conductive resin composition (1-1) for watch cases. The amount of ethanol used was 2% by mass in 100% by mass of conductive resin composition (1-1) for watch cases.

[0031] [Examples 1-2] A conductive resin composition (1-2) for watch cases was prepared in the same manner as in Example 1-1, except that 65 parts by mass of bisphenol F type epoxy resin was weighed out as the main agent and 35 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent.

[0032] [Examples 1-3] A conductive resin composition (1-3) for watch cases was prepared in the same manner as in Example 1-1, except that 55 parts by mass of bisphenol F type epoxy resin was weighed out as the main agent and 45 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent.

[0033] [Examples 1-4] A conductive resin composition (1-4) for watch casings was prepared in the same manner as in Example 1-1, except that 0.3 parts by mass of fumed silica was added to 100 parts by mass of a mixture of the main agent and curing agent and mixed.

[0034] [Examples 1-5] A conductive resin composition (1-5) for watch casings was prepared in the same manner as in Example 1-1, except that 1.0 part by mass of fumed silica was added to 100 parts by mass of a mixture of the main agent and curing agent and mixed.

[0035] [Examples 1-6] A conductive resin composition (1-6) for watch casings was prepared in the same manner as in Example 1-1, except that 450 parts by mass of silver particles were added to 100 parts by mass of a mixture of the main agent and a curing agent and mixed.

[0036] [Examples 1-7] A conductive resin composition (1-7) for watch casings was prepared in the same manner as in Example 1-1, except that 530 parts by mass of silver particles were added to 100 parts by mass of a mixture of the main agent and a curing agent and mixed.

[0037] [Examples 1-8] A conductive resin composition for watch exteriors (1-8) was prepared in the same manner as in Example 1-1, except that ethanol was used in an amount of 3% by mass in 100% by mass of the conductive resin composition for watch exteriors (1-8).

[0038] [Examples 1-9] A conductive resin composition for watch exteriors (1-9) was prepared in the same manner as in Example 1-1, except that ethanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch exteriors (1-9).

[0039] [Examples 1-10] At room temperature, 74 parts by mass of bisphenol F type epoxy resin was weighed out as the main component, and 26 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene was weighed out as the curing agent. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of the main component and curing agent, and then 500 parts by mass of silver particles were added and mixed. Then, ethanol was added to the resulting mixture and mixed to prepare conductive resin composition (1-10) for watch cases. The amount of ethanol used was 2% by mass in 100% by mass of conductive resin composition (1-10) for watch cases.

[0040] [Examples 1-11] A conductive resin composition for watch casings (1-11) was prepared in the same manner as in Examples 1-10, except that 65 parts by mass of bisphenol F type epoxy resin was weighed out as the main agent and 35 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent.

[0041] [Examples 1-12] A conductive resin composition for watch cases (1-12) was prepared in the same manner as in Examples 1-10, except that 55 parts by mass of bisphenol F type epoxy resin was used as the main agent and 45 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was used as the curing agent.

[0042] [Examples 1-13] A conductive resin composition for watch casings (1-13) was prepared in the same manner as in Examples 1-10, except that 0.3 parts by mass of fumed silica was added to 100 parts by mass of a mixture of the main agent and curing agent and mixed.

[0043] [Examples 1-14] A conductive resin composition for watch casings (1-14) was prepared in the same manner as in Examples 1-10, except that 1.0 part by mass of fumed silica was added to 100 parts by mass of a mixture of the main agent and curing agent and mixed.

[0044] [Examples 1-15] A conductive resin composition for watch casings (1-15) was prepared in the same manner as in Examples 1-10, except that 450 parts by mass of silver particles were added to 100 parts by mass of a mixture of the main agent and a curing agent and mixed.

[0045] [Examples 1-16] A conductive resin composition for watch casings (1-16) was prepared in the same manner as in Examples 1-10, except that 530 parts by mass of silver particles were added to 100 parts by mass of a mixture of the main agent and a curing agent and mixed.

[0046] [Examples 1-17] The conductive resin composition for watch exteriors (1-17) was prepared in the same manner as in Example 1-10, except that ethanol was used in an amount of 3% by mass in 100% by mass of the conductive resin composition for watch exteriors (1-17).

[0047] [Examples 1-18] The conductive resin composition for watch exteriors (1-18) was prepared in the same manner as in Example 1-10, except that ethanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch exteriors (1-18).

[0048] [Examples 1-19] At room temperature, 74 parts by mass of bisphenol F type epoxy resin was weighed out as the main component, and 13 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin and 13 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene were weighed out as curing agents. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of the main component and curing agent, and then 500 parts by mass of silver particles were added and mixed. Then, ethanol was added to the resulting mixture and mixed to prepare conductive resin composition for watch exteriors (1-19). The amount of ethanol used was 2% by mass in 100% by mass of conductive resin composition for watch exteriors (1-19).

[0049] [Examples 1-20] The conductive resin composition for watch exteriors (1-20) was prepared in the same manner as in Example 1-19, except that ethanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch exteriors (1-20).

[0050] [Examples 1-21] A conductive resin composition for watch cases (1-21) was prepared in the same manner as in Example 1-1, except that 80 parts by mass of bisphenol F type epoxy resin was weighed out as the main agent and 20 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent.

[0051] [Examples 1-22] A conductive resin composition for watch cases (1-22) was prepared in the same manner as in Example 1-1, except that 50 parts by mass of bisphenol F type epoxy resin was weighed out as the main agent and 50 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent.

[0052] [Examples 1-23] A conductive resin composition for watch casings (1-23) was prepared in the same manner as in Example 1-1, except that 550 parts by mass of silver particles were added to 100 parts by mass of a mixture of the main agent and a curing agent and mixed.

[0053] [Example 2-1] At room temperature, 74 parts by mass of bisphenol F type epoxy resin was weighed out as the main component, and 26 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of the main component and curing agent, and then 500 parts by mass of silver particles were added and mixed. Then, ethylene glycol was added to the resulting mixture and mixed to prepare conductive resin composition for watch cases (2-1). The amount of ethylene glycol used was 2% by mass in 100% by mass of conductive resin composition for watch cases (2-1).

[0054] [Example 2-2] A conductive resin composition for watch cases (2-2) was prepared in the same manner as in Example 2-1, except that ethylene glycol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (2-2).

[0055] [Examples 2-3] At room temperature, 74 parts by mass of bisphenol F type epoxy resin was weighed out as the main component, and 26 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene was weighed out as the curing agent. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of the main component and curing agent, and then 500 parts by mass of silver particles were added and mixed. Then, ethylene glycol was added to the resulting mixture and mixed to prepare conductive resin composition for watch cases (2-3). The amount of ethylene glycol used was 2% by mass in 100% by mass of conductive resin composition for watch cases (2-3).

[0056] [Examples 2-4] A conductive resin composition for watch cases (2-4) was prepared in the same manner as in Example 2-3, except that ethylene glycol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (2-4).

[0057] [Examples 2-5] At room temperature, 74 parts by mass of bisphenol F type epoxy resin was weighed out as the main component, and 13 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin and 13 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene were weighed out as curing agents. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of the main component and curing agent, and then 500 parts by mass of silver particles were added and mixed. Then, ethylene glycol was added to the resulting mixture and mixed to prepare conductive resin composition (2-5) for watch cases. The amount of ethylene glycol used was 2% by mass in 100% by mass of conductive resin composition (2-5) for watch cases.

[0058] [Examples 2-6] A conductive resin composition for watch cases (2-6) was prepared in the same manner as in Example 2-5, except that ethylene glycol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (2-6).

[0059] [Example 3-1] At room temperature, 74 parts by mass of bisphenol F type epoxy resin was weighed out as the main component, and 26 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of the main component and curing agent, and then 500 parts by mass of silver particles were added and mixed. Next, 2-propanol was added to the resulting mixture and mixed to prepare conductive resin composition (3-1) for watch cases. The amount of 2-propanol used was 2% by mass in 100% by mass of conductive resin composition (3-1) for watch cases.

[0060] [Example 3-2] A conductive resin composition (3-2) for watch cases was prepared in the same manner as in Example 3-1, except that 65 parts by mass of bisphenol F type epoxy resin was weighed out as the main agent and 35 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent.

[0061] [Example 3-3] A conductive resin composition for watch cases (3-3) was prepared in the same manner as in Example 3-1, except that 55 parts by mass of bisphenol F type epoxy resin was weighed out as the main agent and 45 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent.

[0062] [Examples 3-4] A conductive resin composition (3-4) for watch cases was prepared in the same manner as in Example 3-1, except that 0.3 parts by mass of fumed silica was added to 100 parts by mass of a mixture of the main agent and curing agent and mixed.

[0063] [Examples 3-5] A conductive resin composition (3-5) for watch cases was prepared in the same manner as in Example 3-1, except that 1.0 part by mass of fumed silica was added to 100 parts by mass of a mixture of the main agent and the curing agent and mixed.

[0064] [Examples 3-6] A conductive resin composition (3-6) for watch cases was prepared in the same manner as in Example 3-1, except that 450 parts by mass of silver particles were added to 100 parts by mass of a mixture of the main agent and a curing agent and mixed.

[0065] [Examples 3-7] A conductive resin composition (3-7) for watch cases was prepared in the same manner as in Example 3-1, except that 530 parts by mass of silver particles were added to 100 parts by mass of a mixture of the main agent and a curing agent and mixed.

[0066] [Examples 3-8] A conductive resin composition for watch cases (3-8) was prepared in the same manner as in Example 3-1, except that 2-propanol was used in an amount of 3% by mass in 100% by mass of the conductive resin composition for watch cases (3-8).

[0067] [Examples 3-9] A conductive resin composition for watch cases (3-9) was prepared in the same manner as in Example 3-1, except that 2-propanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (3-9).

[0068] [Examples 3-10] At room temperature, 74 parts by mass of bisphenol F type epoxy resin was weighed out as the main component, and 26 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene was weighed out as the curing agent. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of the main component and curing agent, and then 500 parts by mass of silver particles were added and mixed. Next, 2-propanol was added to the resulting mixture and mixed to prepare the conductive resin composition for watch cases (3-10). The amount of 2-propanol used was 2% by mass in 100% by mass of the conductive resin composition for watch cases (3-10).

[0069] [Example 3-11] A conductive resin composition for watch cases (3-11) was prepared in the same manner as in Example 3-10, except that 2-propanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (3-11).

[0070] [Examples 3-12] At room temperature, 74 parts by mass of bisphenol F type epoxy resin was weighed out as the main component, and 13 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin and 13 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene were weighed out as curing agents. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of the main component and curing agent, and then 500 parts by mass of silver particles were added and mixed. Next, 2-propanol was added to the resulting mixture and mixed to prepare the conductive resin composition for watch cases (3-12). The amount of 2-propanol used was 2% by mass in 100% by mass of the conductive resin composition for watch cases (3-12).

[0071] [Example 3-13] A conductive resin composition for watch cases (3-13) was prepared in the same manner as in Example 3-12, except that 2-propanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (3-13).

[0072] [Example 4-1] At room temperature, 74 parts by mass of bisphenol F type epoxy resin was weighed out as the main component, and 26 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of the main component and curing agent, and then 500 parts by mass of silver particles were added and mixed. Next, 1-propanol was added to the resulting mixture and mixed to prepare conductive resin composition for watch cases (4-1). The amount of 1-propanol used was 2% by mass in 100% by mass of conductive resin composition for watch cases (4-1).

[0073] [Example 4-2] A conductive resin composition for watch cases (4-2) was prepared in the same manner as in Example 4-1, except that 1-propanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (4-2).

[0074] [Example 4-3] At room temperature, 74 parts by mass of bisphenol F type epoxy resin was weighed out as the main component, and 26 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene was weighed out as the curing agent. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of the main component and curing agent, and then 500 parts by mass of silver particles were added and mixed. Next, 1-propanol was added to the resulting mixture and mixed to prepare the conductive resin composition for watch cases (4-3). The amount of 1-propanol used was 2% by mass in 100% by mass of the conductive resin composition for watch cases (4-3).

[0075] [Example 4-4] A conductive resin composition for watch cases (4-4) was prepared in the same manner as in Example 4-3, except that 1-propanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (4-4).

[0076] [Examples 4-5] At room temperature, 74 parts by mass of bisphenol F type epoxy resin was weighed out as the main component, and 13 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin and 13 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene were weighed out as curing agents. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of the main component and curing agent, and then 500 parts by mass of silver particles were added and mixed. Next, 1-propanol was added to the resulting mixture and mixed to prepare conductive resin composition (4-5) for watch cases. The amount of 1-propanol used was 2% by mass in 100% by mass of conductive resin composition (4-5) for watch cases.

[0077] [Examples 4-6] A conductive resin composition for watch cases (4-6) was prepared in the same manner as in Example 4-5, except that 1-propanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (4-6).

[0078] [Example 5-1] At room temperature, 74 parts by mass of bisphenol F type epoxy resin was weighed out as the main component, and 26 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of the main component and curing agent, and then 500 parts by mass of silver particles were added and mixed. Then, tert-butyl alcohol was added to the resulting mixture and mixed to prepare conductive resin composition (5-1) for watch cases. The amount of tert-butyl alcohol used was 2% by mass in 100% by mass of conductive resin composition (5-1) for watch cases.

[0079] [Example 5-2] A conductive resin composition for watch cases (5-2) was prepared in the same manner as in Example 5-1, except that 65 parts by mass of bisphenol F type epoxy resin was weighed out as the main agent and 35 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent.

[0080] [Example 5-3] A conductive resin composition for watch casings (5-3) was prepared in the same manner as in Example 5-1, except that 55 parts by mass of bisphenol F type epoxy resin was weighed out as the main agent and 45 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent.

[0081] [Example 5-4] A conductive resin composition (5-4) for watch cases was prepared in the same manner as in Example 5-1, except that 0.3 parts by mass of fumed silica was added to 100 parts by mass of a mixture of the main agent and curing agent and mixed.

[0082] [Example 5-5] A conductive resin composition for watch casings (5-5) was prepared in the same manner as in Example 5-1, except that 1.0 part by mass of fumed silica was added to 100 parts by mass of the mixture of the main agent and the curing agent and mixed.

[0083] [Examples 5-6] A conductive resin composition (5-6) for watch cases was prepared in the same manner as in Example 5-1, except that 450 parts by mass of silver particles were added to 100 parts by mass of a mixture of the main agent and a curing agent and mixed.

[0084] [Examples 5-7] A conductive resin composition (5-7) for watch casings was prepared in the same manner as in Example 5-1, except that 530 parts by mass of silver particles were added to 100 parts by mass of a mixture of the main agent and a curing agent and mixed.

[0085] [Examples 5-8] A conductive resin composition for watch cases (5-8) was prepared in the same manner as in Example 5-1, except that tert-butyl alcohol was used in an amount of 3% by mass in 100% by mass of the conductive resin composition for watch cases (5-8).

[0086] [Examples 5-9] A conductive resin composition for watch cases (5-9) was prepared in the same manner as in Example 5-1, except that tert-butyl alcohol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (5-9).

[0087] [Examples 5-10] At room temperature, 74 parts by mass of bisphenol F type epoxy resin was weighed out as the main component, and 26 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene was weighed out as the curing agent. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of the main component and curing agent, and then 500 parts by mass of silver particles were added and mixed. Then, tert-butyl alcohol was added to the resulting mixture and mixed to prepare the conductive resin composition (5-10) for watch cases. The amount of tert-butyl alcohol used was 2% by mass in 100% by mass of the conductive resin composition (5-10) for watch cases.

[0088] [Examples 5-11] A conductive resin composition for watch cases (5-11) was prepared in the same manner as in Example 5-10, except that tert-butyl alcohol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (5-11).

[0089] [Examples 5-12] At room temperature, 74 parts by mass of bisphenol F type epoxy resin was weighed out as the main component, and 13 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin and 13 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene were weighed out as curing agents. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of the main component and curing agent, and then 500 parts by mass of silver particles were added and mixed. Then, tert-butyl alcohol was added to the resulting mixture and mixed to prepare the conductive resin composition for watch cases (5-12). The amount of tert-butyl alcohol used was 2% by mass in 100% by mass of the conductive resin composition for watch cases (5-12).

[0090] [Examples 5-13] A conductive resin composition for watch cases (5-13) was prepared in the same manner as in Example 5-12, except that tert-butyl alcohol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (5-13).

[0091] [Example 6-1] At room temperature, 74 parts by mass of bisphenol F type epoxy resin was weighed out as the main component, and 26 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of the main component and curing agent, and then 500 parts by mass of silver particles were added and mixed. Next, 1-butanol was added to the resulting mixture and mixed to prepare conductive resin composition (6-1) for watch cases. The amount of 1-butanol used was 2% by mass in 100% by mass of conductive resin composition (6-1) for watch cases.

[0092] [Example 6-2] A conductive resin composition for watch cases (6-2) was prepared in the same manner as in Example 6-1, except that 1-butanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (6-2).

[0093] [Example 6-3] At room temperature, 74 parts by mass of bisphenol F type epoxy resin was weighed out as the main component, and 26 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene was weighed out as the curing agent. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of the main component and curing agent, and then 500 parts by mass of silver particles were added and mixed. Next, 1-butanol was added to the resulting mixture and mixed to prepare the conductive resin composition for watch cases (6-3). The amount of 1-butanol used was 2% by mass in 100% by mass of the conductive resin composition for watch cases (6-3).

[0094] [Example 6-4] A conductive resin composition for watch cases (6-4) was prepared in the same manner as in Example 6-3, except that 1-butanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (6-4).

[0095] [Examples 6-5] At room temperature, 74 parts by mass of bisphenol F type epoxy resin was weighed out as the main component, and 13 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin and 13 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene were weighed out as curing agents. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of the main component and curing agent, and then 500 parts by mass of silver particles were added and mixed. Next, 1-butanol was added to the resulting mixture and mixed to prepare conductive resin composition (6-5) for watch cases. The amount of 1-butanol used was 2% by mass in 100% by mass of conductive resin composition (6-5) for watch cases.

[0096] [Example 6-6] A conductive resin composition for watch cases (6-6) was prepared in the same manner as in Example 6-5, except that 1-butanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (6-6).

[0097] [Example 7-1] At room temperature, 74 parts by mass of bisphenol F type epoxy resin was weighed out as the main component, and 26 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of the main component and curing agent, and then 500 parts by mass of silver particles were added and mixed. Next, 2-butanol was added to the resulting mixture and mixed to prepare conductive resin composition for watch cases (7-1). The amount of 2-butanol used was 2% by mass in 100% by mass of conductive resin composition for watch cases (7-1).

[0098] [Example 7-2] A conductive resin composition for watch cases (7-2) was prepared in the same manner as in Example 7-1, except that 2-butanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (7-2).

[0099] [Example 7-3] At room temperature, 74 parts by mass of bisphenol F type epoxy resin was weighed out as the main component, and 26 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene was weighed out as the curing agent. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of the main component and curing agent, and then 500 parts by mass of silver particles were added and mixed. Next, 2-butanol was added to the resulting mixture and mixed to prepare the conductive resin composition for watch cases (7-3). The amount of 2-butanol used was 2% by mass in 100% by mass of the conductive resin composition for watch cases (7-3).

[0100] [Example 7-4] A conductive resin composition for watch cases (7-4) was prepared in the same manner as in Example 7-3, except that 2-butanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (7-4).

[0101] [Examples 7-5] At room temperature, 74 parts by mass of bisphenol F type epoxy resin was weighed out as the main component, and 13 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin and 13 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene were weighed out as curing agents. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of the main component and curing agent, and then 500 parts by mass of silver particles were added and mixed. Next, 2-butanol was added to the resulting mixture and mixed to prepare conductive resin composition for watch cases (7-5). The amount of 2-butanol used was 2% by mass in 100% by mass of conductive resin composition for watch cases (7-5).

[0102] [Examples 7-6] A conductive resin composition for watch cases (7-6) was prepared in the same manner as in Example 7-5, except that 2-butanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (7-6).

[0103] [Example 8-1] At room temperature, 74 parts by mass of bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out as the main components, and 26 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent. Here, the bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out so that the viscosity at 25°C was 50P or less. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of main components and curing agent, and then 500 parts by mass of silver particles were added and mixed. Then, ethanol was added to the resulting mixture and mixed to prepare conductive resin composition for watch cases (8-1). The amount of ethanol used was 2% by mass in 100% by mass of conductive resin composition for watch cases (8-1).

[0104] [Example 8-2] A conductive resin composition for watch casings (8-2) was prepared in the same manner as in Example 8-1, except that a total of 65 parts by mass of bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out as the main components, and 35 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent.

[0105] [Example 8-3] A conductive resin composition for watch casings (8-3) was prepared in the same manner as in Example 8-1, except that a total of 55 parts by mass of bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out as the main components, and 45 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent.

[0106] [Example 8-4] A conductive resin composition (8-4) for watch cases was prepared in the same manner as in Example 8-1, except that 0.3 parts by mass of fumed silica was added to 100 parts by mass of a mixture of the main agent and curing agent and mixed.

[0107] [Example 8-5] A conductive resin composition (8-5) for watch cases was prepared in the same manner as in Example 8-1, except that 1.0 part by mass of fumed silica was added to 100 parts by mass of a mixture of the main agent and the curing agent and mixed.

[0108] [Examples 8-6] A conductive resin composition (8-6) for watch casings was prepared in the same manner as in Example 8-1, except that 450 parts by mass of silver particles were added to 100 parts by mass of a mixture of the main agent and a curing agent and mixed.

[0109] [Examples 8-7] A conductive resin composition (8-7) for watch casings was prepared in the same manner as in Example 8-1, except that 530 parts by mass of silver particles were added to 100 parts by mass of a mixture of the main agent and a curing agent and mixed.

[0110] [Example 8-8] A conductive resin composition for watch exteriors (8-8) was prepared in the same manner as in Example 8-1, except that ethanol was used in an amount of 3% by mass in 100% by mass of the conductive resin composition for watch exteriors (8-8).

[0111] [Examples 8-9] A conductive resin composition for watch exteriors (8-9) was prepared in the same manner as in Example 8-1, except that ethanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch exteriors (8-9).

[0112] [Examples 8-10] At room temperature, 74 parts by mass of bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out as the main components, and 26 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene was weighed out as the curing agent. Here, the bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out so that the viscosity at 25°C was 50P or less. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of main components and curing agent, and then 500 parts by mass of silver particles were added and mixed. Then, ethanol was added to the resulting mixture and mixed to prepare the conductive resin composition for watch cases (8-10). The amount of ethanol used was 2% by mass in 100% by mass of the conductive resin composition for watch cases (8-10).

[0113] [Examples 8-11] A conductive resin composition for watch casings (8-11) was prepared in the same manner as in Examples 8-10, except that a total of 65 parts by mass of bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out as the main components, and 35 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent.

[0114] [Examples 8-12] A conductive resin composition for watch casings (8-12) was prepared in the same manner as in Examples 8-10, except that a total of 55 parts by mass of bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out as the main components, and 45 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent.

[0115] [Examples 8-13] A conductive resin composition for watch casings (8-13) was prepared in the same manner as in Example 8-10, except that 0.3 parts by mass of fumed silica was added to 100 parts by mass of a mixture of the main agent and curing agent and mixed.

[0116] [Examples 8-14] A conductive resin composition for watch casings (8-14) was prepared in the same manner as in Example 8-10, except that 1.0 part by mass of fumed silica was added to 100 parts by mass of a mixture of the main agent and curing agent and mixed.

[0117] [Examples 8-15] A conductive resin composition for watch casings (8-15) was prepared in the same manner as in Example 8-10, except that 450 parts by mass of silver particles were added to 100 parts by mass of a mixture of the main agent and a curing agent and mixed.

[0118] [Examples 8-16] A conductive resin composition for watch casings (8-16) was prepared in the same manner as in Example 8-10, except that 530 parts by mass of silver particles were added to 100 parts by mass of a mixture of the main agent and a curing agent and mixed.

[0119] [Examples 8-17] The conductive resin composition for watch exteriors (8-17) was prepared in the same manner as in Example 8-10, except that ethanol was used in an amount of 3% by mass in 100% by mass of the conductive resin composition for watch exteriors (8-17).

[0120] [Examples 8-18] The conductive resin composition for watch exteriors (8-18) was prepared in the same manner as in Example 8-10, except that ethanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch exteriors (8-18).

[0121] [Examples 8-19] At room temperature, 74 parts by mass of bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out as the main components, and 13 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin and 13 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene were weighed out as curing agents. Here, the bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out so that the viscosity at 25°C was 50P or less. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of main components and curing agents, and then 500 parts by mass of silver particles were added and mixed. Then, ethanol was added to the resulting mixture and mixed to prepare a conductive resin composition for watch cases (8-19). Ethanol was used in an amount of 2% by mass in 100% by mass of the conductive resin composition (8-19) for watch exteriors.

[0122] [Examples 8-20] The conductive resin composition for watch exteriors (8-20) was prepared in the same manner as in Example 8-19, except that ethanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch exteriors (8-20).

[0123] [Example 9-1] At room temperature, 74 parts by mass of bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out as the main components, and 26 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent. Here, the bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out so that the viscosity at 25°C was 50P or less. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of main components and curing agent, and then 500 parts by mass of silver particles were added and mixed. Then, ethylene glycol was added to the resulting mixture and mixed to prepare conductive resin composition for watch cases (9-1). The amount of ethylene glycol used was 2% by mass in 100% by mass of conductive resin composition for watch cases (9-1).

[0124] [Example 9-2] A conductive resin composition for watch cases (9-2) was prepared in the same manner as in Example 9-1, except that ethylene glycol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (9-2).

[0125] [Example 9-3] At room temperature, 74 parts by mass of bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out as the main components, and 26 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene was weighed out as the curing agent. Here, the bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out so that the viscosity at 25°C was 50P or less. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of main components and curing agent, and then 500 parts by mass of silver particles were added and mixed. Then, ethylene glycol was added to the resulting mixture and mixed to prepare the conductive resin composition for watch cases (9-3). The amount of ethylene glycol used was 2% by mass in 100% by mass of the conductive resin composition for watch cases (9-3).

[0126] [Example 9-4] A conductive resin composition for watch cases (9-4) was prepared in the same manner as in Example 9-3, except that ethylene glycol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (9-4).

[0127] [Example 9-5] At room temperature, 74 parts by mass of bisphenol F-type epoxy resin and bisphenol A-type epoxy resin were weighed out as the main components, and 13 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin and 13 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene were weighed out as curing agents. Here, the bisphenol F-type epoxy resin and bisphenol A-type epoxy resin were weighed out so that the viscosity at 25°C was 50P or less. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of main components and curing agents, and then 500 parts by mass of silver particles were added and mixed. Then, ethylene glycol was added to the resulting mixture and mixed to prepare a conductive resin composition (9-5) for watch cases. Ethylene glycol was used in an amount of 2% by mass in 100% by mass of the conductive resin composition for watch casings (9-5).

[0128] [Examples 9-6] A conductive resin composition for watch cases (9-6) was prepared in the same manner as in Example 9-5, except that ethylene glycol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (9-6).

[0129] [Example 10-1] At room temperature, 74 parts by mass of bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out as the main components, and 26 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent. Here, the bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out so that the viscosity at 25°C was 50P or less. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of main components and curing agent, and then 500 parts by mass of silver particles were added and mixed. Next, 2-propanol was added to the resulting mixture and mixed to prepare conductive resin composition (10-1) for watch cases. The amount of 2-propanol used was 2% by mass in 100% by mass of conductive resin composition (10-1) for watch cases.

[0130] [Example 10-2] A conductive resin composition for watch cases (10-2) was prepared in the same manner as in Example 10-1, except that 2-propanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (10-2).

[0131] [Example 10-3] At room temperature, 74 parts by mass of bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out as the main components, and 26 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene was weighed out as the curing agent. Here, the bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out so that the viscosity at 25°C was 50P or less. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of main components and curing agent, and then 500 parts by mass of silver particles were added and mixed. Next, 2-propanol was added to the resulting mixture and mixed to prepare the conductive resin composition (10-3) for watch cases. The amount of 2-propanol used was 2% by mass in 100% by mass of the conductive resin composition (10-3) for watch cases.

[0132] [Example 10-4] A conductive resin composition for watch cases (10-4) was prepared in the same manner as in Example 10-3, except that 2-propanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (10-4).

[0133] [Example 10-5] At room temperature, 74 parts by mass of bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out as the main components, and 13 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin and 13 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene were weighed out as curing agents. Here, the bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out so that the viscosity at 25°C was 50P or less. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of main components and curing agents, and then 500 parts by mass of silver particles were added and mixed. Next, 2-propanol was added to the resulting mixture and mixed to prepare a conductive resin composition (10-5) for watch cases. Furthermore, 2-propanol was used in an amount of 2% by mass in 100% by mass of the conductive resin composition (10-5) for watch exteriors.

[0134] [Example 10-6] A conductive resin composition for watch cases (10-6) was prepared in the same manner as in Example 10-5, except that 2-propanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (10-6).

[0135] [Example 11-1] At room temperature, 74 parts by mass of bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out as the main components, and 26 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent. Here, the bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out so that the viscosity at 25°C was 50P or less. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of main components and curing agent, and then 500 parts by mass of silver particles were added and mixed. Next, 1-propanol was added to the resulting mixture and mixed to prepare conductive resin composition for watch cases (11-1). The amount of 1-propanol used was 2% by mass in 100% by mass of conductive resin composition for watch cases (11-1).

[0136] [Example 11-2] A conductive resin composition for watch cases (11-2) was prepared in the same manner as in Example 11-1, except that 1-propanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (11-2).

[0137] [Example 11-3] At room temperature, 74 parts by mass of bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out as the main components, and 26 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene was weighed out as the curing agent. Here, the bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out so that the viscosity at 25°C was 50P or less. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of main components and curing agent, and then 500 parts by mass of silver particles were added and mixed. Next, 1-propanol was added to the resulting mixture and mixed to prepare the conductive resin composition for watch cases (11-3). The amount of 1-propanol used was 2% by mass in 100% by mass of the conductive resin composition for watch cases (11-3).

[0138] [Example 11-4] A conductive resin composition for watch cases (11-4) was prepared in the same manner as in Example 11-3, except that 1-propanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (11-4).

[0139] [Example 11-5] At room temperature, 74 parts by mass of bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out as the main components, and 13 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin and 13 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene were weighed out as curing agents. Here, the bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out so that the viscosity at 25°C was 50P or less. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of main components and curing agents, and then 500 parts by mass of silver particles were added and mixed. Next, 1-propanol was added to the resulting mixture and mixed to prepare a conductive resin composition (11-5) for watch cases. Furthermore, 1-propanol was used in an amount of 2% by mass in 100% by mass of the conductive resin composition for watch exteriors (11-5).

[0140] [Example 11-6] A conductive resin composition for watch cases (11-6) was prepared in the same manner as in Example 11-5, except that 1-propanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (11-6).

[0141] [Example 12-1] At room temperature, 74 parts by mass of bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out as the main components, and 26 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent. Here, the bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out so that the viscosity at 25°C was 50P or less. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of main components and curing agent, and then 500 parts by mass of silver particles were added and mixed. Then, tert-butyl alcohol was added to the resulting mixture and mixed to prepare conductive resin composition for watch cases (12-1). The amount of tert-butyl alcohol used was 2% by mass in 100% by mass of conductive resin composition for watch cases (12-1).

[0142] [Example 12-2] A conductive resin composition for watch cases (12-2) was prepared in the same manner as in Example 12-1, except that tert-butyl alcohol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (12-2).

[0143] [Example 12-3] At room temperature, 74 parts by mass of bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out as the main components, and 26 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene was weighed out as the curing agent. Here, the bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out so that the viscosity at 25°C was 50P or less. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of main components and curing agent, and then 500 parts by mass of silver particles were added and mixed. Then, tert-butyl alcohol was added to the resulting mixture and mixed to prepare the conductive resin composition for watch cases (12-3). The amount of tert-butyl alcohol used was 2% by mass in 100% by mass of the conductive resin composition for watch cases (12-3).

[0144] [Example 12-4] A conductive resin composition for watch cases (12-4) was prepared in the same manner as in Example 12-3, except that tert-butyl alcohol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (12-4).

[0145] [Example 12-5] At room temperature, 74 parts by mass of bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out as the main components, and 13 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin and 13 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene were weighed out as curing agents. Here, the bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out so that the viscosity at 25°C was 50P or less. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of main components and curing agents, and then 500 parts by mass of silver particles were added and mixed. Then, tert-butyl alcohol was added to the resulting mixture and mixed to prepare a conductive resin composition (12-5) for watch cases. Furthermore, 1-tert-butyl alcohol was used in an amount of 2% by mass in 100% by mass of the conductive resin composition (12-5) for watch casings.

[0146] [Example 12-6] A conductive resin composition for watch cases (12-6) was prepared in the same manner as in Example 12-5, except that tert-butyl alcohol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (12-6).

[0147] [Example 13-1] At room temperature, 74 parts by mass of bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out as the main components, and 26 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent. Here, the bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out so that the viscosity at 25°C was 50P or less. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of main components and curing agent, and then 500 parts by mass of silver particles were added and mixed. Next, 1-butanol was added to the resulting mixture and mixed to prepare conductive resin composition for watch cases (13-1). The amount of 1-butanol used was 2% by mass in 100% by mass of conductive resin composition for watch cases (13-1).

[0148] [Example 13-2] A conductive resin composition for watch cases (13-2) was prepared in the same manner as in Example 13-1, except that 1-butanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (13-2).

[0149] [Example 13-3] At room temperature, 74 parts by mass of bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out as the main components, and 26 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene was weighed out as the curing agent. Here, the bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out so that the viscosity at 25°C was 50P or less. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of main components and curing agent, and then 500 parts by mass of silver particles were added and mixed. Next, 1-butanol was added to the resulting mixture and mixed to prepare the conductive resin composition for watch cases (13-3). The amount of 1-butanol used was 2% by mass in 100% by mass of the conductive resin composition for watch cases (13-3).

[0150] [Example 13-4] A conductive resin composition for watch cases (13-4) was prepared in the same manner as in Example 13-3, except that 1-butanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (13-4).

[0151] [Example 13-5] At room temperature, 74 parts by mass of bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out as the main components, and 13 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin and 13 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene were weighed out as curing agents. Here, the bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out so that the viscosity at 25°C was 50P or less. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of main components and curing agents, and then 500 parts by mass of silver particles were added and mixed. Next, 1-butanol was added to the resulting mixture and mixed to prepare a conductive resin composition (13-5) for watch cases. Furthermore, 1-butanol was used in an amount of 2% by mass in 100% by mass of the conductive resin composition for watch casings (13-5).

[0152] [Example 13-6] A conductive resin composition for watch cases (13-6) was prepared in the same manner as in Example 13-5, except that 1-butanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (13-6).

[0153] [Example 14-1] At room temperature, 74 parts by mass of bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out as the main components, and 26 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent. Here, the bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out so that the viscosity at 25°C was 50P or less. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of main components and curing agent, and then 500 parts by mass of silver particles were added and mixed. Next, 2-butanol was added to the resulting mixture and mixed to prepare conductive resin composition for watch cases (14-1). The amount of 2-butanol used was 2% by mass in 100% by mass of conductive resin composition for watch cases (14-1).

[0154] [Example 14-2] A conductive resin composition for watch cases (14-2) was prepared in the same manner as in Example 14-1, except that 2-butanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (14-2).

[0155] [Example 14-3] At room temperature, 74 parts by mass of bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out as the main components, and 26 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene was weighed out as the curing agent. Here, the bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out so that the viscosity at 25°C was 50P or less. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of main components and curing agent, and then 500 parts by mass of silver particles were added and mixed. Next, 2-butanol was added to the resulting mixture and mixed to prepare the conductive resin composition for watch cases (14-3). The amount of 2-butanol used was 2% by mass in 100% by mass of the conductive resin composition for watch cases (14-3).

[0156] [Example 14-4] A conductive resin composition for watch cases (14-4) was prepared in the same manner as in Example 14-3, except that 2-butanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (14-4).

[0157] [Example 14-5] At room temperature, 74 parts by mass of bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out as the main components, and 13 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin and 13 parts by mass of 1,18-(hydrazinocarbonyl)-7,11-octadecadiene were weighed out as curing agents. Here, the bisphenol F type epoxy resin and bisphenol A type epoxy resin were weighed out so that the viscosity at 25°C was 50P or less. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of main components and curing agents, and then 500 parts by mass of silver particles were added and mixed. Next, 2-butanol was added to the resulting mixture and mixed to prepare a conductive resin composition (14-5) for watch cases. Furthermore, 2-butanol was used in an amount of 2% by mass in 100% by mass of the conductive resin composition for watch casings (14-5).

[0158] [Examples 14-6] A conductive resin composition for watch cases (14-6) was prepared in the same manner as in Example 14-5, except that 2-butanol was used in an amount of 4.5% by mass in 100% by mass of the conductive resin composition for watch cases (14-6).

[0159] [Comparative Example 1-1] At room temperature, 74 parts by mass of bisphenol F type epoxy resin was weighed out as the main component, and 26 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of the main component and curing agent, and then 500 parts by mass of silver particles were added and mixed. Then, ethanol was added to the resulting mixture and mixed to prepare conductive resin composition for watch exteriors (15-1). The amount of ethanol used was 1% by mass in 100% by mass of conductive resin composition for watch exteriors (15-1).

[0160] [Comparative Example 1-2] A conductive resin composition for watch exteriors (15-2) was prepared in the same manner as in Comparative Example 1-1, except that ethanol was used in an amount of 10% by mass in 100% by mass of the conductive resin composition for watch exteriors (15-2).

[0161] [Comparative Examples 1-3] At room temperature, 74 parts by mass of bisphenol F type epoxy resin was weighed out as the main component, and 26 parts by mass of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin was weighed out as the curing agent. Next, 0.5 parts by mass of fumed silica was added to 100 parts by mass of the mixture of the main component and curing agent, and then 400 parts by mass of silver particles were added and mixed. Then, ethanol was added to the resulting mixture and mixed to prepare the conductive resin composition for watch cases (15-3). The amount of ethanol used was 2% by mass in 100% by mass of the conductive resin composition for watch cases (15-3). Table 1 shows the types and amounts of components used in the preparation of the conductive resin compositions for watch casings (1-1) to (15-3) in Examples 1-1 to Comparative Examples 1-3.

[0162] [Evaluation Method and Results] The bezel and case were assembled using the conductive resin compositions (1-1) to (15-3) for watch exteriors. First, as shown in Figure 2, the conductive resin composition (resin composition C) prepared above was applied to the case 6 at the 12 o'clock and 6 o'clock positions when the dial 10 was placed inside. Next, the resin packing 8 was placed in the case 6 and the bezel 4 was press-fitted. Then, the case 6 with the press-fitted bezel 4 was heated at 80°C for 1 hour. In this way, the assembly of the bezel and case was produced. In the above, assemblies were also fabricated when the case 6 with the bezel 4 pressed into it was heated at 80°C for 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, or 4 hours. Furthermore, assemblies were also fabricated when the case 6 with the bezel 4 pressed into it was heated at 60°C for 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4.5 hours, 5 hours, 5.5 hours, 6 hours, 6.5 hours, 7 hours, 7.5 hours, or 8 hours. The resulting assembly was tested for conductivity. Specifically, a tester was used to measure the resistance by touching the probe to the bezel and case. If the resistance was 100Ω or less, it could be said that conductivity was achieved. In other words, a suitable hardened material for conductivity was formed in the gap between the watch bezel and case. Therefore, it is thought that a watch using such an assembly can prevent adverse effects on the movement when static electricity is generated near the bezel. Table 1 shows the evaluation results. The column for 80°C (hours) indicates how many hours of heating were required for the assembly to achieve a resistance of 100Ω or less. The column for 60°C (hours) also indicates how many hours of heating were required for the assembly to achieve a resistance of 100Ω or less. In Comparative Example 1-1, the resistance did not reach 100Ω or less even after heating at 80°C for 8 hours and at 60°C for 8 hours. This is thought to be because the curing reaction did not proceed and a cured product could not be formed. In Comparative Example 1-2, the viscosity of the conductive resin composition for watch cases was low, causing it to sag when applied to the case. As a result, an assembly could not be made. In Comparative Example 1-3, the resistance did not reach 100Ω or less even after heating at 80°C for 8 hours and at 60°C for 8 hours. Even if a cured product was formed, it is thought that there were few silver particles and pathways could not be formed within the cured product. For this reason, in Table 1, the evaluation results for Comparative Examples 1-1 to 1-3 are indicated as ×.

[0163] [Table 1]

[0164] [Table 2]

[0165] [Table 3]

[0166] [Table 4]

[0167] [Table 5]

[0168] [Table 6]

[0169] [Table 7]

[0170] [Table 8]

[0171] [Table 9]

[0172] Based on the above, the present invention relates to the following. [1] A conductive resin composition for watch exteriors comprising an epoxy resin having a viscosity of 50P or less at 25°C and comprising at least one selected from the group consisting of bisphenol A type epoxy resin and bisphenol F type epoxy resin; a curing agent comprising at least one selected from the group consisting of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin and 1,18-(hydrazinocarbonyl)-7,11-octadecadiene; flake-shaped silver particles; fumed silica; and an alcohol having 2 to 4 carbon atoms, wherein when the total amount of the epoxy resin and the curing agent is 100 parts by mass, the silver particles are contained in an amount of 450 parts by mass or more, and the alcohol is contained in an amount of 2% by mass or more and less than 5% by mass. [2] The conductive resin composition for watch exteriors according to [1], wherein the viscosity at 25°C is 10P or more and 50P or less. [3] The silver particles have a 50% average particle size of 7.0 μm or more and 9.5 μm or less, and a tap density of 4.5 g / cm³. 3 More than 5.3g / cm 3 The conductive resin composition for watch exteriors described in [1] is as follows: [4] The conductive resin composition for watch exteriors according to [1], comprising 0.3 parts by mass or more and 1.0 part by mass or less of fumed silica when the total amount of the epoxy resin and the curing agent is 100 parts by mass. [5] The conductive resin composition for watch exteriors according to [1], wherein when the total amount of the epoxy resin and the curing agent is 100 parts by mass, the epoxy resin is present in an amount of 55 parts by mass or more and 75 parts by mass or less, and the curing agent is present in an amount of 25 parts by mass or more and 45 parts by mass or less. [6] A watch comprising a cured product of the conductive resin composition for watch exteriors described in [1]. [Explanation of symbols]

[0173] 2. Windshield 4 Bezels 6 Torso 8. Plastic gasket 10 Dial 12 Movements 14 Case back A Cured product B Gap C Resin composition

Claims

1. An epoxy resin comprising at least one selected from the group consisting of bisphenol A type epoxy resin and bisphenol F type epoxy resin, wherein the viscosity at 25°C is 50P or less, A curing agent comprising at least one selected from the group consisting of 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin and 1,18-(hydrazinocarbonyl)-7,11-octadecadiene, Scale-like silver particles, Fumed silica and, It contains an alcohol with 2 to 4 carbon atoms, When the total amount of the epoxy resin and the curing agent is 100 parts by mass, the silver particles are contained in an amount of 450 parts by mass or more. The aforementioned alcohol is contained in an amount of 2% by mass or more and less than 5% by mass. A conductive resin composition for watch casings.

2. The viscosity at 25°C is between 10P and 50P. The conductive resin composition for watch casings according to claim 1.

3. The silver particles have a 50% average particle size of 7.0 μm or more and 9.5 μm or less. The conductive resin composition for watch casings according to claim 1.

4. When the total amount of the epoxy resin and the curing agent is 100 parts by mass, the fumed silica is contained in an amount of 0.3 parts by mass or more and 1.0 part by mass or less. The conductive resin composition for watch casings according to claim 1.

5. When the total amount of the epoxy resin and the curing agent is 100 parts by mass, the epoxy resin is contained in an amount of 55 parts by mass or more and 75 parts by mass or less, and the curing agent is contained in an amount of 25 parts by mass or more and 45 parts by mass or less. The conductive resin composition for watch casings according to claim 1.

6. A watch comprising a cured product of the conductive resin composition for watch casing described in claim 1.

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