Rubber member, manufacturing method thereof and application method thereof

Abstract

To provide a rubber member capable of inhibiting static electrification when detached from a component having abutted, and preventing damages of the component.SOLUTION: A rubber member includes a fluororubber foam as a base material. The rubber member has 0.5% to 7.5% difference between nitrogen atom% of a surface of the rubber member by an XPS analysis (X-ray photoelectron spectroscopy analysis) and nitrogen atom% of an inside of the rubber member by the XPS analysis.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a rubber component, its manufacturing method, and its use. [Background technology]

[0002] Fluorine foamed rubber, which has excellent heat resistance, chemical resistance and low outgassing properties, is widely used in the fields of automobiles, electricity and construction, etc., demonstrating excellent performance as cushioning materials, shock-absorbing materials, pressure-relieving materials, sealing materials, heat insulating materials and the like.

[0003] However, conventional foamed fluororubber such as that described in Patent Document 1 may cause a strong charge to be applied to the mating member with which it comes into contact.

[0004] When used in electrical equipment or device manufacturing equipment, there is a concern that when a mating member having a fine electrical circuit is peeled off from the foamed fluororubber member, the fine electrical circuit may be destroyed due to strong electrostatic charge. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-256565 [Patent Document 2] Japanese Patent Publication No. 2022-60895 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in response to such problems, and has an object to provide a rubber member that suppresses charging when separated from a contacting member, thereby suppressing damage to the member. [Means for solving the problem]

[0007] In order to achieve the object, a rubber member according to one aspect of the present invention comprises: A rubber member using a foamed fluororubber as a base material, characterized in that the difference between the nitrogen atomic percentage determined by XPS analysis (X-ray photoelectron spectroscopy) of the surface of the rubber member and the nitrogen atomic percentage determined by XPS analysis of the interior of the rubber member is 0.5% or more and 7.5% or less. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a rubber member that suppresses charging when it is separated from a member that it has come into contact with. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a table showing the results of examples and comparative examples. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0011] The rubber member of the first embodiment of the present invention is a rubber member having a foamed fluororubber member as a base material, in which the difference between the nitrogen atomic % determined by XPS (X-ray photoelectron spectroscopy) analysis of the surface of the rubber member and the nitrogen atomic % determined by XPS analysis of the interior of the member, obtained by subtracting the latter, is 0.5% or more and 7.5% or less.

[0012] In this case, the foamed fluororubber used as the base material is often in the form of closed cells, and foamed fluororubber having an open cell ratio of 50% or less is preferably used, more preferably an open cell ratio of 25% or less, and even more preferably 10% or less.

[0013] The rubber member of this embodiment preferably contains carbon black.

[0014] Furthermore, the rubber member of this embodiment is preferably a rubber member in which the difference between the nitrogen atomic % determined by XPS analysis of the surface of the member and the nitrogen atomic % determined by XPS analysis of the interior of the member is 1.5% or more and 4.5% or less.

[0015] The method for manufacturing a rubber member of the second embodiment is a method for manufacturing a rubber member in which an aminosilane agent is applied by a dipping method or a spraying method and an alcohol is used as a solvent, and preferably a monoalcohol having up to 4 carbon atoms.

[0016] Furthermore, the method for using the rubber member of the third embodiment is a method for using the rubber member as a contact member that is used in contact with any of quartz, glass, polyamides, polyamines, polyacrylamides, polyvinyl alcohols, poly-N-vinyl polymers, poly(meth)acrylic acids, cellophane, and silk, which have an insulating portion, and can be separated from the same.

[0017] The first embodiment will be further described below.

[0018] The foamed fluororubber material used as the substrate in this embodiment may typically be the foamed fluororubber described in Patent Document 1, cited above. The fluororubber material used may typically be a fluororubber known as FKM (ASTM abbreviation), which offers a good balance between cost and performance. Of course, depending on the application, it may also be possible to use FFKM (ASTM abbreviation), which is made entirely of fluorine and has higher heat resistance and chemical resistance, although this is more expensive. These fluororubber materials have high durability, heat resistance, chemical resistance, and oil resistance, as well as high flexibility, making them suitable for use in cushioning materials, shock-absorbing materials, pressure-relieving materials, sealing materials, adhesive materials, heat-insulating materials, and the like.

[0019] Furthermore, the fluororubber used as the base material in this embodiment is a foam. As a foam, it is very lightweight and very flexible, and therefore can be more suitably applied to cushioning materials, shock-absorbing materials, pressure-relieving materials, sealing materials, adhesive materials, and heat-insulating materials. It is well known to those skilled in the art that foams can be formed by the method described in Patent Document 1, for example.

[0020] In this embodiment, the porosity of the foam may be 30% or more and 95% or less, preferably 40% or more and 95% or less, and more preferably 50% or more and 90% or less.

[0021] The density of fluororubber materials is known to be around 1.80 to 1.90 g / ml for FKM, and 1.90 to 2.00 g / ml even when they contain fillers such as carbon black. Therefore, the porosity can be calculated by cutting out a rectangular parallelepiped, determining its volume, and measuring its weight. Furthermore, if the material contains fully open cells, the porosity can be calculated as is. If the material contains closed cells, the closed cells can be converted into open cells using a number of sharp, needle-like structures, and then all the voids can be crushed under high pressure. The porosity can also be calculated from the original volume and the volume after high pressure. The cross section can also be photographed using an electron microscope and image processing can be used to calculate the porosity.

[0022] The size of the voids, or pore diameter, of the rubber member of this embodiment may be determined depending on the application or purpose of use, but a diameter of several μm to 300 μm is preferred. The pore diameter varies, with a median pore diameter of approximately 50-100 μm being commonly used. However, this is not a limitation. It is acceptable for pores to be particularly small or large to exist; a small number of pores does not significantly affect the properties. The pore diameter can be observed using a microscope such as an electron microscope.

[0023] Next, the rubber member of this embodiment may have a void structure that is either open-cell or closed-cell. While both types are flexible in terms of flexibility, closed-cell rubbers offer high durability in terms of elastic recovery and thermal insulation, and are therefore preferred for use in shock-absorbing materials, shock-absorbing materials, pressure-relieving materials, sealing materials, contact materials, and thermal insulation materials. However, the choice depends on the specific intended use, and open-cell rubbers are not excluded. Furthermore, open-cell rubbers and closed-cell rubbers are not mutually exclusive. When expressed in terms of open-cell ratio, a high open-cell ratio is generally referred to as open-cell rubber, and a low open-cell ratio is generally referred to as closed-cell rubber. Therefore, in this embodiment, closed-cell rubbers preferably have an open-cell ratio of 50% or less, more preferably 25% or less, and even more preferably 10% or less.

[0024] Since the rubber member of this embodiment has a porous form, it is extremely flexible and elastic compared to non-porous, i.e., bulk fluororubber, and can therefore exhibit excellent properties as a sealing member, buffer material, heat insulating material, pressure relief material, and contact material. The inventors have found that when used as a sealing member, even if bulk fluororubber is subjected to a torsional force and the seal breaks down, the extremely flexible properties of the rubber member ensure sealing performance.

[0025] The open cell ratio referred to here can be measured by a method such as that described in Patent Document 2. That is, a rubber member of a certain size is submerged in water, reduced pressure is applied, and the member is left to stand for about 10 minutes, after which the pressure is returned to normal, and the open cell portion is filled with water. From this state, all the absorbed water is squeezed out using a two-roller or similar tool, and the weight is measured to determine the volume of absorbed water. This is considered to be the volume of the open cell portion, and the open cell ratio can be calculated as a percentage by dividing this by the total volume of voids calculated from the above-mentioned void ratio.

[0026] The rubber material that can be used in this embodiment preferably contains fine particles of carbon black, silica, or the like, which are called fillers, in order to adjust the physical properties.

[0027] Next, the rubber member of this embodiment is a rubber member in which the difference between the nitrogen atomic % measured on the surface of the member by XPS (X-ray photoelectron spectroscopy) analysis and the nitrogen atomic % measured inside the member by XPS analysis is 0.5% to 7.5%. This state can be achieved by chemically modifying the surface portion. The method for doing so will be described below.

[0028] In the rubber member of this embodiment, the difference between the nitrogen atomic percentage measured on the surface by XPS (X-ray photoelectron spectroscopy) analysis and the nitrogen atomic percentage measured inside the member by XPS analysis is 0.5% to 7.5%, and the nitrogen content on the surface is higher than the nitrogen content inside. This state can be achieved, for example, by modifying the surface with a chemical modifier having an amine functional group. A specific example is a method of modifying the surface by applying a silane coupling agent having an amine functional group to the surface of foamed fluororubber and then heat-treating it.

[0029] Silane coupling agents having an amine functional group (also called aminosilane agents) include: (C2H5O)3SiC3H6-NH2, (C2H5O)3SiC3H6-NH-Ph, (CH3O)2Si(CH3)-C3H6-NH-C2H4-NH2, (CH3O)3SiC3H6-NH-C2H4-NH2, (CH3O)3SiC3H6-NH2 Examples of such methods include, but are not limited to, those described above. Furthermore, a state in which the surface of this embodiment is rich in nitrogen atoms can also be achieved by applying a polymer containing amine functional groups to the surface as a dilute solution using a solvent. The function of this embodiment is realized by achieving a state in which the surface is rich in nitrogen atoms, and while preferred implementation methods have been described above, methods for achieving a state in which the difference between the nitrogen atomic percentage determined by XPS (X-ray photoelectron spectroscopy) analysis of the surface and the nitrogen atomic percentage determined by XPS analysis of the interior of the rubber member of this embodiment is 0.5% or more and 7.5% or less are not limited to these.

[0030] When modifying the surface with an aminosilane agent, the surface of the rubber member can be treated with plasma or the like in advance to prevent deterioration after the surface modification, which is thought to be due to the formation of chemical bonds, and to obtain better durability. Also, rubber members containing carbon black as a filler are preferably used because the aminosilane agent can chemically bond to the functional groups present in the carbon black.

[0031] Regarding the thickness and shape of the rubber member in this embodiment, the surface of which has a higher atomic percentage of nitrogen than the interior, if it is in sheet form, a thickness of 0.5 mm or more, preferably 1 to 2 mm or more, is usually used. This is determined according to the purpose and means of sealing or cushioning, including the size, and the thickness of the member in this embodiment should not be considered limiting, but effectively, a thickness of 0.5 mm or more is used.

[0032] Furthermore, considering cases where the rubber member is not on a sheet, the upper limit of the thickness depends on the adjacent or contacting member or the overall shape including them when used as a cushioning member, shock-resistant member, pressure-relieving member, sealing member, contact member, heat-insulating member, etc., and is not limited to a planar or rectangular parallelepiped structure but is three-dimensional and may include curves or curved surfaces, and since the main effect of this embodiment is the function of the contact surface with the mating member, it cannot be limited, and it is thought that there is no point in limiting it. In short, the rubber member of this embodiment can be configured so that the part that comes into direct contact with the mating member matches the shape of the mating member, and the other parts can take the shape required for the overall shape.

[0033] Furthermore, the rubber member of this embodiment must be surface-modified on the surface that comes into contact with a mating member, which may cause charging problems. This provides the effects of this embodiment. When the rubber member is in the form of a sheet, it is necessary for the surface that comes into contact with the mating member to have a high nitrogen atomic percentage, which is the condition of this embodiment. The surface of other areas may or may not be surface-modified. Similarly, even in the case of a shape other than a sheet, as long as the necessary parts are surface-modified, the other parts may or may not be surface-modified. However, when surface modification is typically performed, the surface often becomes too hard, which may make it difficult to maintain good cushioning properties, impact resistance, or adhesion and sealing properties. Therefore, it is best not to make the surface harder than necessary, and it is preferable that only the necessary parts are surface-modified.

[0034] Therefore, in this embodiment, the difference between the nitrogen atomic % determined by XPS analysis (X-ray photoelectron spectroscopy) on the surface of a rubber member and the nitrogen atomic % determined by XPS analysis inside the member is 0.5% or more and 7.5% or less. This means that the surface of the member may be not the entire surface of the rubber member of this embodiment, but only a portion of the surface of the member.

[0035] The rubber member of this embodiment typically has a minimum thickness of about 0.5 mm. Since it can be used as a buffer, shock-absorbing member, pressure-relieving member, sealing member, contact member, heat-insulating member, etc., a certain thickness of about 0.5 mm or more is required. This refers to the thickness at the contact surface with the mating member, such as a buffer, shock-absorbing member, pressure-relieving member, sealing member, contact member, heat-insulating member, etc., and other portions may be thinner or thicker than this. Furthermore, the thickness is preferably 1 mm or more.

[0036] The maximum thickness is not particularly limited, but is usually 500 mm or less, preferably 300 mm or less. When used as a sealing member, the thickness is 100 mm or less, preferably 20 mm or less, in view of the requirement for airtightness.

[0037] Now, we will explain why the difference between the nitrogen atomic % measured on the surface of the rubber member of this embodiment by an XPS (X-ray photoelectron spectroscopy) analyzer and the nitrogen atomic % measured inside the member by XPS analysis is 0.5% or more and 7.5% or less.

[0038] The component surface referred to here literally means the surface of the component, and the region measured using an XPS (X-ray photoelectron spectroscopy) analyzer is the nanometer-order region of the surface (for example, within 10 nm from the surface). The interior of the component refers to a depth of at least 20% of the surface, or, in cases where the thickness is thinner, at least 0.2 mm from the actual measurement conditions. To measure the interior, the surface is scraped off or the surface of a sheet is cut to expose the interior, and then the XPS (X-ray photoelectron spectroscopy) analyzer is used for measurement. In the case of a sheet, if only one side has a surface-modified nitrogen-rich layer, the untreated back side can be measured to determine the interior.

[0039] XPS analysis (X-ray photoelectron spectroscopy) is an analytical method well known to those skilled in the art. Surface component analysis can be performed using an XPS analyzer such as the ULVAC-PHI Quantera SXM. When analyzing the rubber member of this embodiment, charge neutralization is typically performed using Al Kα monochromatic X-rays (E = 1486.6 eV) with a 20 μm diameter and electron and Ar ion irradiation. Detection can be performed using (Pass Energy): E = 280 eV, 1 eV step (Survey), E = 112 eV, 0.1 eV step (C1s, O1s, F1s, N1s, Si2p), but is not limited to these conditions. For example, the nitrogen atomic percentage value obtained by XPS analysis of the surface of the rubber member can be measured within 10 nm from the surface, and the nitrogen atomic percentage value obtained by XPS analysis of the interior of the rubber member can be measured within 20% or more of the thickness from the surface, and the difference between the respective nitrogen atomic percentages can be calculated. The nitrogen atomic percentages obtained in this manner are used in this embodiment.

[0040] In the rubber member of this embodiment, the difference between the nitrogen atomic percentage determined by XPS (X-ray photoelectron spectroscopy) analysis of the surface of the member and the nitrogen atomic percentage determined by XPS analysis of the interior of the member is 0.5% to 7.5%. If the difference is less than 0.5%, the charging of the mating member is often insufficient. If the total nitrogen atomic percentage is less than 0.5% and the difference between the surface nitrogen atomic percentage and the interior nitrogen atomic percentage is too small, the cushioning, sealing, and impact resistance may be insufficient. If the difference is more than 7.5%, the surface nitrogen atomic percentage may be too high, causing the mating member to be highly charged with the opposite sign to the normal charge, or the surface may become too hard, resulting in poor cushioning, sealing, and impact resistance. A more preferable range for the difference between the nitrogen atomic percentage determined by XPS analysis of the surface of the member and the nitrogen atomic percentage determined by XPS analysis of the interior of the member is 1.5% to 4.5%.

[0041] In addition to XPS analysis, the difference between the surface and the interior of the rubber member of this embodiment can also be easily determined by measuring the difference between the surface and the interior using a micro-hardness tester. The micro-hardness tester can be measured using a Type C indenter of the Micro Hardness Tester MD-1capa manufactured by Kobunshi Keiki Co., Ltd. Hardness can also be determined by subtracting the interior hardness from the surface hardness. The rubber member used in this embodiment can have a hardness of 8 to 60, preferably 10 to 50, as measured by a Type C indenter of the Micro Hardness Tester MD-1capa manufactured by Kobunshi Keiki Co., Ltd. Similar to XPS analysis, the hardness difference can be measured by measuring the surface and the interior, which has been subjected to a surface finishing process such as cutting, and then calculating the difference.

[0042] In this embodiment, the difference between the surface hardness and the internal hardness measured using a Type C indenter on a Micro Rubber Hardness Tester MD-1capa manufactured by Kobunshi Keiki Co., Ltd. is preferably 0.5 or more and 13.0 or less. If the difference is less than 0.5, the electrostatic charge suppression of the mating member is often insufficient. If the difference is less than 0.5 and the overall hardness is high, the cushioning, sealing, and impact resistance may be insufficient. If the difference is more than 13.0, the surface hardness may be too high, causing the mating member to be highly charged with the opposite sign to the normal charge, or the surface may be too hard, resulting in poor cushioning, sealing, and impact resistance. A more preferable difference is 1.5 or more and 7.0 or less.

[0043] A rubber member of this embodiment, which has a foamed fluororubber base material and in which the difference between the nitrogen atomic % measured on the surface of the member by XPS (X-ray photoelectron spectroscopy) analysis and the nitrogen atomic % measured inside the member by XPS analysis is 0.5% to 7.5%, is used in contact with insulating materials such as quartz, glass, polyamides, polyamines, polyacrylamides, polyvinyl alcohols, poly-N-vinyl polymers, poly(meth)acrylic acid, cellophane, and silk, and suppresses peel electrification of the mating member when the contact state is broken. The degree of charge suppression can be evaluated, for example, by bringing the rubber member of this embodiment into contact with a mating member and then peeling it off, and measuring the surface potential of the mating member.

[0044] Furthermore, when assessing performance as a buffer member, shock-resistant buffer member, pressure buffer member, sealing member, contact member, or heat insulating material, a certain degree of evaluation can be made by examining, for example, sealing properties. The foamed fluororubber member of this embodiment is a soft member having a certain degree of hardness and elasticity, and if it is found to have contact and sealing properties under a certain pressure, it is considered to be suitable in terms of these performances.

[0045] Next, a second embodiment of the present invention will be described. In this second embodiment of the present invention, an aminosilane agent is applied to a foamed fluororubber by dipping or spraying, using alcohol as a solvent. Examples of the aminosilane agent used include those described above. When applying the aminosilane agent to an untreated foamed fluororubber surface, the agent is usually diluted with a solvent to achieve a thin coating. Dilution is often performed to a weight percentage of several percent to approximately 10% or 20%. Alcohol is preferred as the dilution solvent because it dissolves the aminosilane agent well, is volatile, and effectively adheres to the foamed fluororubber. It is also preferable to add a small amount of water. More preferred alcohols are monoalcohols with up to four carbon atoms, with 2-butanol, propanol, isopropanol, ethanol, and methanol being particularly preferred. The preferred application method is dipping or spraying using a diluted solution. Spraying is preferred as a method for applying the agent only to the required surface that comes into contact with the contacting member.

[0046] After coating in this manner, the solvent is dried and the ink is heat-treated at a temperature of about 100°C to 150°C to fix the ink.

[0047] A third embodiment of the present invention is a method of using the rubber member of the first embodiment of the present invention as a contact member that is used in contact with, and can be separated from, any of members having an insulating portion, such as quartz, glass, polyamides, polyamines, polyacrylamides, polyvinyl alcohols, poly-N-vinyl polymers, poly(meth)acrylic acids, cellophane, and silk.

[0048] The rubber member according to the first embodiment of the present invention can effectively suppress charge buildup on members such as quartz, glass, polyamides, polyamines, polyacrylamides, polyvinyl alcohols, poly-N-vinyl polymers, poly(meth)acrylic acids, cellophanes, and silk when they come into contact with and are separated from the members, i.e., when they are separated from the members, and can effectively suppress discharge and static electricity interference, etc. Therefore, the rubber member can be used to suppress discharge and static electricity interference, etc., as a member that can come into contact with and be separated from members such as quartz, glass, polyamides, polyamines, polyacrylamides, polyvinyl alcohols, poly-N-vinyl polymers, poly(meth)acrylic acids, cellophanes, and silk, such as a sealant for oil circuits in automobiles, an impact-resistant member, an insulating material, a buffer member for members forming fine circuits in electrical and electronic devices, or a buffer member, sealant, impact-resistant member, or insulating material used in construction or daily life.

[0049] Polyamides refer to polymers that have amide bonds as repeating unit structures, such as nylon 6, nylon 11, nylon 12, nylon 66, nylon 610, nylon 6T, nylon 6I, nylon 9T, nylon M5T, and nylon 612. They also include copolymers of these polymers.

[0050] The term "polyamines" refers to polymers having a repeating unit structure with an amine functional group, and includes copolymers thereof.

[0051] The polyacrylamides refer to polymers having a repeating unit structure obtained by polymerizing acrylamide or methacrylamide monomers, and include copolymers thereof.

[0052] Polyvinyl alcohols are polymers having the repeating unit structure -CH2CH(OH)-, and include copolymers thereof.

[0053] The poly-N-vinyl polymers refer to polymers having a repeating unit structure of a polymer having an N-vinyl structure, and include copolymers thereof.

[0054] The term "poly(meth)acrylic acids" refers to polymers having a polymer structure of acrylic acid or methacrylic acid as a repeating unit structure, and includes copolymers thereof.

[0055] Cellophanes are polymers made from viscose, and include modified cellophanes.

[0056] Silks refer to polymers made from silk, including modified ones. [Example]

[0057] Example 1 A 5cm x 5cm sheet (thickness is shown in the table) of foamed fluororubber sheet DF700S-86 or AF-150 manufactured by Sanfuku Kogyo Co., Ltd. was spray coated or dip coated (dipping time 1 minute) with a solution of aminosilane agent ((CHO)Si(CH)-CH-NH-CH-NH) dissolved in ethanol / water (90 / 10), then dried at 80°C for 1 hour and left to stand at 120°C for 2 hours to create a sample.

[0058] The aminosilane content was varied from 2% to 15% by weight, and samples were created with the numbers listed in the table below. For each spray-coated sample, XPS analysis of the coated and uncoated surfaces was performed using a ULVAC-PHI Quantera SXM under the conditions described above. The surface and interior components were analyzed, and the difference in nitrogen atomic percentage (atomic percentage) was calculated by subtracting the surface from the interior. The dip-coated sample underwent XPS analysis on the coated surface. The sample was then cut at the center of the thickness direction to expose the interior, and the resulting section was analyzed using XPS. The hardness measurements were also performed on the surface and interior components using the same XPS analysis method, using a Type C indenter on a Kobunshi Keiki MD-1capa micro rubber hardness tester. The hardness differences are listed in the table shown in Figure 1.

[0059] The peeling electrification was evaluated as follows using a foamed fluororubber sample cut to 20 mm x 20 mm and used as the sample, and a 50 mm x 50 mm quartz glass with a thickness of 1 mm as the mating member.

[0060] Measurement method; 1. Place a 1mm thick piece of quartz glass on a grounded electrode and neutralize it with an ionizer or similar device. 2. The surface-treated side of the sample subjected to the surface treatment of this embodiment is brought into contact with quartz glass. 3. After 300 seconds of contact with the sample under a load of 800 g (load 2 g / mm2), the sample is peeled off from the quartz glass. 4. The potential of the quartz glass is measured using a surface potential meter (Trek Model 34). Three measurements are taken, and the average value is used. 5. +300V to -300V was marked with a ◎, +500V to +300V or -300V to -500V was marked with a ○, and cases exceeding +500V or less than -500V were marked with an ×.

[0061] For sealing, samples of the thicknesses listed in the table were punched out to 40mm x 40mm, leaving the outer shape intact, to form square frames with an outer diameter of 50mm x 50mm and a width of 5mm. A 2cm diameter hole was drilled in the top of an acrylic pressure-resistant vacuum chamber, and the seal was created through this hole. To seal, a 100mm x 100mm quartz glass plate with a thickness of 5mm was placed on top of a 50mm x 50mm x 5mm square frame-shaped fluorocarbon foam rubber member. A 1kg weight was placed on top of the quartz glass to apply pressure from above. The pressure-resistant vacuum chamber was then depressurized with a vacuum pump to a pressure differential between the chamber pressure and atmospheric pressure of -0.1kPa to -0.45kPa. After leaving the chamber for 5 minutes, if the pressure differential changed by less than 50% of atmospheric pressure, the test was evaluated as "good"; if it changed by more than 50%, the test was evaluated as "bad."

[0062] However, please note the following points. 1) When the void ratio of any of the foamed fluororubber samples used in the Examples and Comparative Examples before coating was calculated by measuring the weight per unit volume, it was between 58% and 89%. Furthermore, when the hardness before coating was measured using a Type C indenter on a micro rubber hardness tester MD-1capa manufactured by Kobunshi Keiki Co., Ltd., all of the values ​​were between 12 and 22. 2) The open cell ratio was measured by the method described in JP-A-2022-60895. 3) Among the samples in the examples, AF-150 was used for No. 4. DF700S-86 was used for the others. 4) Comparative Example No. 3 was prepared by applying the coating by the dipping method, and the dipping time was set to 96 hours so that the aminosilane agent penetrated deep into the interior. 5) Before coating, the porous portion of the foamed fluororubber sheet of Example No. 6 was pierced several times with a pin holder used in flower arranging to set the open cell ratio to 47%. 6) In Example No. 8, the solvent for the coating liquid was isopropanol instead of ethanol. 7) In Comparative Example No. 6, polyvinylidene fluoride was used as the material for the fluororesin bulk.

[0063] Example 2 For samples No. 4 to No. 9 of Example 1, when the counterpart member was soda lime glass and the peel electrification property and the sealing property were evaluated, all of the samples were rated as ⊚ for electrification property and ◯ for sealing property.

[0064] The samples of Comparative Examples No. 1 to No. 6 in Example 1 were used with soda lime glass as the mating member, and the peel electrification properties and sealing properties were evaluated. The results were the same as those of Example 1.

[0065] Example 3 For samples No. 4 to No. 9 of Example 1, the counterpart members were nylon 6 and nylon 66, and the peel electrification properties and sealing properties were evaluated. For both nylons, the electrification properties were rated as ⊚ and the sealing properties were rated as ◯.

[0066] Furthermore, when the sample of Comparative Example No. 1 in Example 1 was used with nylon 66 as the mating member and evaluated for peel electrification and sealing property, the electrification property was evaluated as poor and the sealing property as good.

[0067] Furthermore, when the sample of Comparative Example No. 3 in Example 1 was used with nylon 6 as the mating member and evaluated for peel electrification and sealing property, the electrification property was rated as excellent and the sealing property was rated as poor.

[0068] Example 4 When the sample No. 3 of Example 1 was used with polyvinyl alcohol as the mating member and the peel electrification property and the sealing property were evaluated, the electrification property was rated as ⊚ and the sealing property was rated as ◯.

[0069] Example 5 When the sample No. 3 of Example 1 was used with polytertiary butyl acrylamide or poly-N-vinylpyrrolidone as the mating member and the peel electrification property and the sealing property were evaluated, the electrification property was rated as ⊚ and the sealing property was ◯.

[0070] Example 6 Sample No. 9 of Example 1 was used as a mating member in which polyallylamine was coated on a polycarbonate substrate, and the peeling electrification property and sealing property were evaluated. The electrification property was rated as excellent and the sealing property was rated as good.

[0071] Example 7 Sample No. 7 of Example 1 was used as the mating member, which was a member in which silk was coated on a polycarbonate substrate, and the peeling electrification property and sealing property were evaluated. The electrification property was rated as ⊚ and the sealing property was ◯.

[0072] Example 8 When the sample No. 5 of Example 1 was used with cellophane as the mating member and evaluated for peel electrification property and sealing property, the electrification property was rated as excellent and the sealing property was rated as good.

[0073] Example 9 Sample No. 5 of Example 1 was used as a mating member in which polyacrylic acid was coated on a polycarbonate substrate, and the peeling electrification property and sealing property were evaluated. The electrification property was rated as ⊚ and the sealing property was ◯.

[0074] Example 10 A foamed fluororubber sheet having the same porosity and open cell ratio as the foamed fluororubber sheet used in No. 5 of Example 1 but containing no carbon black was used, and the same surface treatment as in No. 5 was performed. XPS component analysis revealed that the difference between the surface nitrogen atomic percentage and the internal nitrogen atomic percentage was 1.8%, and the hardness difference was also 2.4. When this was evaluated in the same manner as in Example 1, the peel electrification property was rated good and the sealing property was rated good.

[0075] <Summary of the embodiment> The disclosure herein includes rubber components, methods of making rubber components, and methods of using rubber components.

[0076] (Item 1) A rubber member using a foamed fluororubber as a base material, characterized in that the difference between the nitrogen atomic percentage determined by XPS analysis (X-ray photoelectron spectroscopy) of the surface of the rubber member and the nitrogen atomic percentage determined by XPS analysis of the interior of the rubber member is 0.5% or more and 7.5% or less.

[0077] (Item 2) 2. The rubber member according to item 1, wherein the open cell ratio is 50% or less.

[0078] (Item 3) 3. The rubber member according to item 1 or 2, wherein the porosity of the rubber member is 30% or more and 95% or less.

[0079] (Item 4) the value of nitrogen atomic % by the XPS analysis of the surface of the rubber member is a value measured within 10 nm from the surface, 4. The rubber member according to any one of items 1 to 3, wherein the value of nitrogen atomic % in the interior of the rubber member by the XPS analysis is a measured value within 20% or more of the thickness from the surface.

[0080] (Item 5) 5. The rubber component according to any one of items 1 to 4, containing carbon black.

[0081] (Item 6) 6. The rubber member according to any one of items 1 to 5, wherein the difference between the nitrogen atomic % determined by XPS analysis of the surface of the member and the nitrogen atomic % determined by XPS analysis of the interior of the member is 1.5% or more and 4.5% or less.

[0082] (Item 7) a step of applying an aminosilane agent using an alcohol as a solvent to foamed fluororubber to obtain a rubber member; A method for manufacturing a rubber member, characterized in that the difference between the nitrogen atomic percentage determined by XPS analysis (X-ray photoelectron spectroscopy) of the surface of the rubber member and the nitrogen atomic percentage determined by XPS analysis of the interior of the rubber member is 0.5% or more and 7.5% or less.

[0083] (Item 8) 8. The method for producing a rubber member according to item 7, wherein the coating is carried out by a dipping method or a spraying method.

[0084] (Item 9) Item 9. The method for producing a rubber member according to Item 7 or 8, wherein the step of obtaining the rubber member comprises a step of heat treating the rubber member at 100°C to 150°C.

[0085] (Item 10) 10. The method for producing a rubber member according to any one of items 7 to 9, wherein the open cell ratio is 50% or less.

[0086] (Item 11) 11. The method for producing a rubber member according to any one of items 7 to 10, wherein the rubber member contains carbon black.

[0087] (Item 12) Item 12. The method for producing a rubber member according to any one of items 7 to 11, wherein a difference between the nitrogen atomic % determined by XPS analysis of the surface of the member and the nitrogen atomic % determined by XPS analysis of the interior of the member is 1.5% or more and 4.5% or less.

[0088] (Item 13) 7. A method for using the rubber member according to any one of items 1 to 6, wherein the rubber member is used as a contact member that can be used in contact with and separated from any one of quartz, glass, polyamides, polyamines, polyacrylamides, polyvinyl alcohols, poly-N-vinyl polymers, poly(meth)acrylic acids, cellophane, and silk, which has an insulating portion.

Claims

1. A rubber member using a foamed fluororubber as a base material, characterized in that the difference between the nitrogen atomic % determined by XPS analysis (X-ray photoelectron spectroscopy) of the surface of the rubber member and the nitrogen atomic % determined by XPS analysis of the interior of the rubber member is 0.5% or more and 7.5% or less.

2. 2. The rubber member according to claim 1, wherein the open cell ratio is 50% or less.

3. The rubber member according to claim 1, wherein the porosity of the rubber member is 30% or more and 95% or less.

4. the value of nitrogen atomic % by the XPS analysis of the surface of the rubber member is a value measured within 10 nm from the surface, The rubber member according to claim 1, wherein the value of nitrogen atomic % in the interior of the rubber member determined by the XPS analysis is a measured value from the surface to an interior depth of 20% or more of the thickness.

5. The rubber member according to claim 1, further comprising carbon black.

6. 2. The rubber member according to claim 1, wherein the difference between the nitrogen atomic % determined by XPS analysis of the surface of the member and the nitrogen atomic % determined by XPS analysis of the interior of the member is 1.5% or more and 4.5% or less.

7. a step of applying an aminosilane agent using an alcohol as a solvent to foamed fluororubber to obtain a rubber member; A method for manufacturing a rubber member, characterized in that the difference between the nitrogen atomic % determined by XPS analysis (X-ray photoelectron spectroscopy) of the surface of the rubber member and the nitrogen atomic % determined by XPS analysis of the interior of the rubber member is 0.5% or more and 7.5% or less.

8. The method for producing a rubber member according to claim 7, wherein the coating is performed by a dipping method or a spraying method.

9. The method for producing a rubber member according to claim 7, wherein the step of obtaining the rubber member comprises a step of heat treating the rubber member at 100°C to 150°C.

10. The method for producing a rubber member according to claim 7, wherein the open cell ratio is 50% or less.

11. The method for producing a rubber member according to claim 7, wherein the rubber material contains carbon black.

12. The method for producing a rubber member according to claim 7, wherein a difference between the nitrogen atomic % determined by XPS analysis of the surface of the member and the nitrogen atomic % determined by XPS analysis of the interior of the member is 1.5% or more and 4.5% or less.

13. 7. A method for using the rubber member according to any one of claims 1 to 6, wherein the rubber member is used as a contact member that can be used in contact with and separated from any one of quartz, glass, polyamides, polyamines, polyacrylamides, polyvinyl alcohols, poly-N-vinyl polymers, poly(meth)acrylic acids, cellophane, and silk, which has an insulating portion.

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