Electronic photography member and electronic photography image forming device

Abstract

To provide an electronic photography member capable of suppressing an increase in resistance during long-term use.SOLUTION: The elastic layer contains a silicone rubber, a cation represented by the following structural formula (1), and an anion, the anion is a bis (fluorosulfonyl) imide anion, a loss tangent of the elastic layer at a temperature of 50 °C. is defined as tan δ 50, when a loss tangent of the elastic layer at a temperature of 200 °C. is defined as tan δ 200, a temperature dependence tan δ TD of the loss tangent represented by the following formula (A) is - 4.0 * 10-4 or more and 0 or less, when a hardness obtained by measuring the elastic layer with a micro rubber hardness meter is defined as H0, and a hardness obtained by measuring the elastic layer with the micro rubber hardness meter after the elastic layer is immersed in methyl hydrogen silicone oil for 24 hours and cured is defined as H1, H1 / H0 is 1.2 or more and 1.9 or less. A electronic photography member comprising: SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an electrophotographic member used in an electrophotographic image forming apparatus such as a copying machine or a printer, and to an electrophotographic image forming apparatus. [Background technology]

[0002] In some electrophotographic image forming apparatuses, intermediate transfer belts that use at least one elastic layer in their layer structure (hereinafter also referred to as elastic intermediate transfer belts) are used to achieve high image quality. Elastic intermediate transfer belts are known to be effective in preventing hollow toner particles because they are soft due to the presence of at least one elastic layer in their layer structure and can reduce the pressure acting on the toner in the transfer section.

[0003] Furthermore, since it has good adhesion to paper in the secondary transfer section, it is known to be effective not only in improving transfer efficiency for ordinary paper but also in transferability for thick paper and for transferability for paper with irregularities, and elastic intermediate transfer belts are known that contain silicone rubber in the elastic layer, which has excellent conformability to the irregularities of paper.When silicone rubber is used in the elastic layer, it is known that an ionic conductive agent is contained in the elastic layer to impart conductivity.

[0004] As the ionic conductive agent, bis(trifluoromethanesulfonyl)imide (TFSI) anion is often used from the viewpoints of conductivity and cost. Patent Document 1 describes an electrophotographic member in which an ionic conductive agent containing TFSI anion is contained in an elastic layer containing silicone rubber.

[0005] On the other hand, in recent years, regulations on PFAS (perfluoroalkyl and polyfluoroalkyl substances), which are highly persistent in the environment and bioaccumulate, have been strengthened. Bis(fluorosulfonyl)imide (FSI) anions are known as non-PFAS anions. Patent Documents 2 and 3 describe silicone rubber compositions containing FSI anions, and electrophotographic members using such silicone rubber compositions in elastic layers are also conceivable. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-94187 [Patent Document 2] International Publication No. 2014 / 69622 [Patent Document 3] International Publication No. 2014 / 69623 Summary of the Invention [Problem to be solved by the invention]

[0007] As a result of extensive research by the present inventors, it was found that electrophotographic members using in their elastic layers silicone rubber compositions containing FSI anions, as described in Patent Documents 2 and 3, showed a significant increase in resistance when energized for an extended period of time. Since FSI anions have a smaller molecular size and are more mobile than TFSI anions, it is believed that an ionic conductive agent containing FSI anions may experience a large increase in resistance. When such electrophotographic members, which show a large increase in resistance when energized for an extended period of time, are used as intermediate transfer belts, the transferability of images changes over extended use. Therefore, an electrophotographic member capable of suppressing the increase in resistance is desired.

[0008] Therefore, an object of the present invention is to provide an electrophotographic member capable of suppressing an increase in resistance during long-term use, and further to provide an electrophotographic image forming apparatus equipped with the electrophotographic member as an intermediate transfer belt. [Means for solving the problem]

[0009] The above object can be achieved by the present invention, which provides: 1. An electrophotographic member having, in order, a base layer, an elastic layer, and a surface layer, The elastic layer contains silicone rubber, a cation represented by the following structural formula (1), and an anion, the anion is a bis(fluorosulfonyl)imide anion, The loss tangent of the elastic layer at a temperature of 50°C is tanδ 50 The loss tangent of the elastic layer at a temperature of 200°C is tanδ 200 When this is the case, the temperature dependence of the loss tangent, tanδ, is given by the following formula (A): TD But -4.0×10 -4 is greater than or equal to 0 and less than or equal to The electrophotographic member is characterized in that, when the hardness of the elastic layer measured with a micro rubber hardness tester is H0, and the hardness of the elastic layer measured with the micro rubber hardness tester after immersing the elastic layer in methyl hydrogen silicone oil for 24 hours and curing it is H1, H1 / H0 is 1.2 or more and 1.9 or less. [ka] (In structural formula (1), R 1 and R 2 are each independently a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, provided that R 1 and R 2 At least one of the groups is a group having at least one alkenyl group.

number

[0010] According to the present invention, it is possible to provide an electrophotographic member capable of suppressing an increase in resistance during long-term use, and also to provide an electrophotographic image forming apparatus equipped with the electrophotographic member as an intermediate transfer belt. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view showing an example of an image-forming apparatus using an electrophotographic member of the present invention. [Figure 2] 1 is a cross-sectional view showing a layer structure of an electrophotographic member of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be described in detail below with reference to preferred embodiments. <One embodiment> One embodiment is for electrophotographic members. The electrophotographic member of the present invention comprises: 1. An electrophotographic member having, in order, a base layer, an elastic layer, and a surface layer, The elastic layer contains silicone rubber, a cation represented by the following structural formula (1), and an anion, the anion is a bis(fluorosulfonyl)imide anion, The loss tangent of the elastic layer at a temperature of 50°C is tanδ 50 The loss tangent of the elastic layer at a temperature of 200°C is tanδ 200 When this is the case, the temperature dependence of the loss tangent, tanδ, is given by the following formula (A): TD But -4.0×10 -4 is greater than or equal to 0 and less than or equal to The hardness of the elastic layer measured with a micro rubber hardness tester is defined as H0, and the elastic layer is immersed in methyl hydrogen silicone oil for 24 hours, cured, and then the hardness of the elastic layer measured with the micro rubber hardness tester is defined as H1. The hardness of the elastic layer measured with the micro rubber hardness tester is defined as H1, and the ratio H1 / H0 is 1.2 or more and 1.9 or less. [ka] (In structural formula (1), R 1 and R 2 are each independently a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, provided that R 1 and R 2 At least one of the groups is a group having at least one alkenyl group.

number

[0013] The present inventors speculate that the reason why the effects of the present invention are achieved by having the above characteristics is as follows. Normally, when an ionic conductive agent is added to rubber, the conductivity is proportional to the number of charged carrier ions. Since resistivity is the inverse of conductivity, resistivity increases as the number of carrier ions decreases. When a transfer voltage is applied to an electrophotographic member over a long period of time, cations move to the negative electrode and anions move to the positive electrode, and the cations and anions that reach the electrodes are oxidized and reduced, respectively, losing their charge. It is speculated that the increase in resistance occurs because the number of carrier ions decreases due to the application of voltage over a long period of time.

[0014] The electrophotographic member of the present invention has a base layer, an elastic layer, and a surface layer in this order, and the elastic layer contains a silicone rubber, a cation represented by the structural formula (1), and an anion, and the anion is a bis(fluorosulfonyl)imide anion.

[0015] The electrophotographic member of the present invention has a loss tangent of the elastic layer at a temperature of 50° C. of tanδ 50 , the loss tangent of the elastic layer at a temperature of 200°C is tanδ 200 When the temperature dependence of the loss tangent shown in the above formula (A) is TD is -4.0 x 10 -4 If the cross-linked structure of the silicone rubber is developed and has stable viscoelasticity, the temperature dependency of the loss tangent becomes small, and tanδ TD It is believed that the cross-linked structure of the silicone rubber develops, which inhibits the migration of carrier ions to the electrodes during long-term application of electricity, thereby inhibiting an increase in resistance.

[0016] In the electrophotographic member of the present invention, the hardness of the elastic layer measured with a micro rubber hardness tester is defined as H0, and the hardness of the elastic layer measured with a micro rubber hardness tester after immersing the elastic layer in methyl hydrogen silicone oil for 24 hours and curing is defined as H1. When silicone rubber is immersed in methyl hydrogen silicone oil for 24 hours and cured, the more vinyl groups remaining in the silicone rubber, the more the hardness increases due to reaction with the methyl hydrogen silicone oil. In other words, when H1 / H0 is 1.2 or more, it is considered that a sufficient number of vinyl groups remain in the silicone rubber.

[0017] The cation represented by the structural formula (1) has an imidazolium ring and at least one alkenyl group, and is thought to interact with the vinyl groups remaining in the silicone rubber. As described above, a sufficient number of vinyl groups remain in the silicone rubber of the present invention. It is presumed that the strong interaction of the cation represented by the structural formula (1) with the silicone rubber inhibits migration to the electrode during long-term application of current, thereby suppressing an increase in resistance. As a result of the above-mentioned mechanism, the effects of the present invention can be achieved by the synergistic effects exerted on each other.

[0018] In the electrophotographic member of the present invention, the group having an alkenyl group in the structural formula (1) is preferably an allyl group, and R 1 and R 2 However, it is more preferable that the cation is an allyl group. In this case, it is presumed that the interaction between the cation and the silicone rubber is stronger, thereby suppressing the increase in resistance.

[0019] In the electrophotographic member of the present invention, the total amount of the cations and anions is preferably 0.5 parts by mass or more and 10.0 parts by mass or less, based on 100 parts by mass of the silicone rubber. This range ensures a good initial resistance range for the electrophotographic member. The types and relative amounts of chemical substances in the present invention can be confirmed, for example, by nuclear magnetic resonance (NMR).

[0020] The initial resistance is 1.0 x 10 8 Ω cm or more 3.0×10 12 It is preferable that the resistance is Ω·cm or less, and 1.0×10 9 Ω cm or more 1.0×10 11 It is more preferable that the resistivity is Ω·cm or less, and the transferability is improved when the electrophotographic member is used as an intermediate transfer belt.

[0021] The electrophotographic member of the present invention has the above-mentioned tan δ TD But -4.0×10 -4 Over -1.0×10 -4 Within this range, when the electrophotographic member is used as an intermediate transfer belt, the ability to conform to the irregularities of paper is improved, resulting in improved transferability.

[0022] The electrophotographic member of the present invention is an electrophotographic member having a base layer, an elastic layer, and a surface layer in this order, and the elastic layer is (A) a cation represented by the following structural formula (1): (B) bis(fluorosulfonyl)imide anion, (C) a copolymerized organopolysiloxane represented by the following structural formula (2): (D) a copolymerized organopolysiloxane represented by the following structural formula (3): The cured product of the mixture contains the above compound, and is characterized in that the ratio of the number of Si-H groups to the number of Si-vinyl groups in the mixture (H / Vi) is 0.5 or more and 0.9 or less. [ka] (In structural formula (1), R 1 and R2 are each independently a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, provided that R 1 and R 2 At least one of the groups is a group having at least one alkenyl group. [ka] (In structural formula (2), m 1 and m 2 are integers greater than or equal to 1, and R 3 is either a methyl group or a vinyl group. [ka] (In structural formula (3), n 1 and n 2 are integers greater than or equal to 1.)

[0023] The copolymerized organopolysiloxane represented by structural formula (2) has vinyl groups in its side chains, which is thought to develop a crosslinked silicone rubber structure when cured. The development of the crosslinked silicone rubber structure is thought to inhibit the migration of carrier ions to the electrodes during long-term application of current, thereby suppressing an increase in resistance.

[0024] The ratio of the number of Si-H groups to the number of Si-vinyl groups in the mixture (H / Vi) is 0.5 or more and 0.9 or less. When H / Vi is 0.9 or less, the number of Si-vinyl groups in the mixture is greater than the number of Si-H groups, and it is thought that sufficient vinyl groups remain in the silicone rubber that is the cured product. Furthermore, when H / Vi is 0.5 or more, it is thought that the silicone rubber has sufficient strength and therefore sufficient durability as an electrophotographic member.

[0025] The cation represented by the structural formula (1) has an imidazolium ring and at least one alkenyl group, and is thought to interact with the vinyl groups remaining in the silicone rubber. As described above, a sufficient number of vinyl groups remain in the silicone rubber of the present invention. It is presumed that the strong interaction of the cation represented by the structural formula (1) with the silicone rubber inhibits migration to the electrode during long-term application of current, thereby suppressing an increase in resistance. As a result of the above-mentioned mechanism, the effects of the present invention can be achieved by the synergistic effects exerted on each other.

[0026] When the total amount of (C) and (D) in the mixture is 100 parts by mass, the total amount of (A) and (B) in the mixture is preferably 0.5 parts by mass or more and 10.0 parts by mass or less. This is the same as the total amount of cations and anions per 100 parts by mass of silicone rubber being 0.5 parts by mass or more and 10.0 parts by mass or less. This range ensures that the initial resistance of the electrophotographic member is in a good range. The initial resistance is preferably in the above range, and the transferability when the electrophotographic member is used as an intermediate transfer belt is improved.

[0027] Next, the configuration of the electrophotographic member of the present invention will be described. Also, the configuration of each of the electrophotographic members will be described, and a method for manufacturing the same will be described. However, the present invention is not limited to the following description.

[0028] The electrophotographic member of this embodiment is a laminate composed of at least three layers, namely, a base layer 21, an elastic layer 22, and a surface layer 23, as illustrated in Fig. 2. However, the present invention is not limited to these three layers, and a primer layer for improving adhesion may be added between the base layer 21 and the elastic layer 22. On the other hand, from the viewpoint of not impairing the flexibility of the elastic layer, it is preferable not to provide a primer layer for improving adhesion between the elastic layer 22 and the surface layer 23.

[0029] [Base layer] The base layer 21 in the present invention will be described. The electrophotographic member of the present invention has a base layer 21. The base layer 21 in the present invention is a cylindrical, seamless type in the form of a roll or belt, and examples of materials suitable for the base layer 21 include resin materials such as polyether ether ketone, polyethylene terephthalate, polybutylene naphthalate, polyester, polyimide, polyamide, polyamideimide, polyacetal, polyphenylene sulfide, and polyvinylidene fluoride.

[0030] The resin for the base layer 21 may be made conductive by adding a conductive compound such as metal powder, conductive oxide powder, conductive carbon, lithium salt, or ionic liquid. Combinations of other resins and conductive agents may also be used. The thickness of the base layer 21 is preferably 10 μm or more and 500 μm or less. If the thickness is less than 10 μm, the mechanical strength will be significantly reduced, and if the thickness is more than 500 μm, the rigidity will be too high, making it difficult to use as an intermediate transfer member.

[0031] [Elastic layer] Next, the elastic layer 22 in the present invention will be described. The electrophotographic member of the present invention has an elastic layer 22. The elastic layer 22 needs to have appropriate flexibility in order to conform to the surface shape of the recording medium. In the present invention, silicone rubber with small compression set (JISK 6262) is used even in the low hardness range.

[0032] Silicone rubber is a cured product obtained by curing an addition-curing liquid silicone rubber. Generally, addition-curing liquid silicone rubber contains the following components (a), (b), and (c): Component (a): an organopolysiloxane having an unsaturated aliphatic group; Component (b): an organopolysiloxane having active hydrogen atoms bonded to silicon atoms; Component (c): a platinum compound as a crosslinking catalyst.

[0033] Examples of the organopolysiloxane having an unsaturated aliphatic group, component (a), include the following: Both ends of the molecule are (X 1 )2X 3 SiO 1 / 2 The intermediate unit is (X 1 )2SiO or X 1 X 2 a linear organopolysiloxane represented by SiO; X in intermediate units 1 SiO 3 / 2 or SiO 4 / 2 A branched organopolysiloxane comprising: Above X 1 represents an unsubstituted or substituted monovalent hydrocarbon group that is bonded to the silicon atom in the above formula and does not contain an unsaturated aliphatic group. Specific examples of such hydrocarbon groups include the following: Alkyl groups (e.g., methyl, ethyl, propyl, butyl, pentyl, hexyl, etc.), Aryl groups (phenyl, naphthyl, etc.).

[0034] Examples of the substituent that the hydrocarbon group may have include a halogen atom, an alkoxy group, a cyano group, etc. Specific examples of the substituted hydrocarbon group include a chloromethyl group, a 3-chloropropyl group, a 3-cyanopropyl group, and a 3-methoxypropyl group. Among these, X 1 It is preferable that 50% or more of X are methyl groups, and all of X 1 is more preferably a methyl group.

[0035] Above X 2 represents an unsaturated aliphatic group bonded to the silicon atom in the above formula. Examples of unsaturated aliphatic groups include vinyl groups, allyl groups, 3-butenyl groups, 4-pentenyl groups, and 5-hexenyl groups. Among these, vinyl groups are preferred because they are easy to synthesize and handle and facilitate the crosslinking reaction of silicone rubber.

[0036] Above X 3 represents either the above hydrocarbon group or the above unsaturated aliphatic group. As the hydrocarbon group, a methyl group is preferred, and as the unsaturated aliphatic group, a vinyl group is preferred. In the present invention, the component (a) is a copolymerized organopolysiloxane represented by the following structural formula (2). [ka] (In structural formula (2), m 1 and m 2 are integers greater than or equal to 1, and R 3 is either a methyl group or a vinyl group.

[0037] The weight average molecular weight of the copolymerized organopolysiloxane represented by the above structural formula (2) is preferably from 10,000 to 100,000, and more preferably from 20,000 to 40,000. In the present invention, the weight average molecular weight can be determined, for example, from the intrinsic viscosity of the polymer.

[0038] m in the above structural formula (2) 1 m for 2 The ratio is preferably 0.5% or more and 10% or less, and more preferably 3% or more and 6% or less. 1 and m 2 The ratio of can be confirmed by, for example, nuclear magnetic resonance (NMR).

[0039] Specific examples of copolymerized organopolysiloxanes represented by the above structural formula (2) include VDT-123, VDT-131, VDT-431, VDT-731, and VDT-954 manufactured by Gelest, but the present invention is not limited to these.

[0040] The component (a) may contain a plurality of copolymerized organopolysiloxanes represented by the structural formula (2) above, or may contain an organopolysiloxane having an unsaturated aliphatic group other than the copolymerized organopolysiloxane represented by the structural formula (2) above.

[0041] The unsaturated aliphatic group equivalent of the component (a) is preferably 0.1 eq / kg or more. The unsaturated aliphatic group equivalent refers to the number of unsaturated aliphatic groups contained per 1 kg of component (a). The larger the unsaturated aliphatic group equivalent, the more developed the crosslinked structure of the silicone rubber becomes. When the unsaturated aliphatic group equivalent is 0.1 eq / kg or more, the migration of carrier ions to the electrode during long-term current application is suppressed, which is thought to suppress an increase in resistance.

[0042] The organopolysiloxane having active hydrogen bonded to silicon atoms, component (b), is a crosslinking agent that reacts with the unsaturated aliphatic groups in component (a) under the catalytic action of the platinum compound, component (c), to form a crosslinked structure.

[0043] The number of active hydrogen atoms bonded to silicon atoms in the silicon-bonded active hydrogen-containing organopolysiloxane, component (b), is preferably an average of more than three per molecule. The silicon-bonded organic groups in the silicon-bonded active hydrogen-containing organopolysiloxane of component (b) include X in component (a). 1 Examples include unsubstituted or substituted monovalent hydrocarbon groups that do not contain unsaturated aliphatic groups, such as those shown in the formula (1). In particular, a methyl group is preferred as the hydrocarbon group because of its ease of synthesis and handling.

[0044] In the present invention, the component (b) is a copolymerized organopolysiloxane represented by the following structural formula (3). [ka] (In structural formula (3), n 1 and n 2 are integers greater than or equal to 1.)

[0045] The weight average molecular weight of the copolymerized organopolysiloxane represented by the above structural formula (3) is preferably 500 or more and 10,000 or less, and more preferably 1,000 or more and 3,000 or less. n in the above structural formula (3) 1 n for 2The ratio is preferably 5% or more and 60% or less, and more preferably 20% or more and 40% or less.

[0046] In the above structural formula (3), n 2 is preferably an integer of 3 or more, and more preferably an integer of 7 or more. Specific examples of copolymerized organopolysiloxanes represented by the above structural formula (3) include HMS-031, HMS-071, HMS-151, HMS-301, and HMS-501 manufactured by Gelest, but the present invention is not limited to these.

[0047] The component (b) may contain a plurality of copolymerized organopolysiloxanes represented by the structural formula (3), or may contain an organopolysiloxane having active hydrogen bonded to a silicon atom other than the copolymerized organopolysiloxane represented by the structural formula (3).

[0048] The active hydrogen group equivalent of component (b) is preferably at least 2.0 eq / kg, where active hydrogen group equivalent refers to the number of active hydrogen groups bonded to silicon atoms contained per kg of component (b). As the component (c), known platinum compounds can be used.

[0049] Furthermore, in order to impart conductivity to the elastic layer 22, a conductive agent must be added. In the present invention, an ionic conductive agent is added in order to suppress uneven resistance caused by the dispersibility of the conductive agent.

[0050] As described above, in the present invention, an ionic conductive agent comprising a cation represented by the following structural formula (1) and a bis(fluorosulfonyl)imide anion is used as the ionic conductive agent. [ka] (In structural formula (1), R 1 and R 2 are each independently a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, provided that R 1 and R2 At least one of the groups is a group having at least one alkenyl group.

[0051] Specific examples of ionic conductive agents comprising a cation represented by the structural formula (1) and a bis(fluorosulfonyl)imide anion are listed below in Table 1, but the present invention is not limited to these.

[0052] [Table 1]

[0053] The thickness of the elastic layer 22 is preferably about 100 to 1000 μm, and more preferably about 200 to 400 μm. In addition, the elastic layer 22 in the present invention may also contain other additives such as fillers, crosslinking accelerators, crosslinking retarders, crosslinking aids, scorch inhibitors, anti-aging agents, softeners, heat stabilizers, flame retardants, flame retardant aids, ultraviolet absorbers, and rust inhibitors.

[0054] Intermediate transfer belts require flame retardancy because they conduct electricity through the transfer area. It is difficult to ensure the necessary flame retardancy with various elastomers and rubbers without adding flame retardants. Flame retardants include metal hydroxides such as magnesium hydroxide and aluminum hydroxide that utilize endothermic properties, platinum compounds and phenolic compounds that inhibit thermal decomposition, intumescent compounds that have an oxygen-blocking effect, and phosphate ester condensation compounds. Examples of fillers include reinforcing fillers such as fumed silica, crystalline silica, wet silica, fumed titanium oxide, and cellulose nanofiber.

[0055] [tanδ TD About As mentioned above, tanδ TD is -4.0×10 -4 When the value is equal to or greater than 0, the cross-linked structure of the silicone rubber is developed, and the movement of carrier ions to the electrode during long-term current application is suppressed, which is thought to suppress the increase in resistance.

[0056] tanδ TD Specifically, it can be evaluated by the following method. A sample (length 10 mm, width 5 mm, thickness 260 μm) is prepared by cutting out the elastic layer 22 of the electrophotographic member. This sample of the elastic layer 22 is set in a tensile measurement attachment of a dynamic viscoelasticity measuring device (DMA) equipped with a heating furnace, and measurement is performed while changing the temperature condition at a vibration frequency of 10 Hz, making it possible to measure the loss tangent tanδ at each temperature.

[0057] The measured loss tangent tanδ at a temperature of 50°C is 50 The measured value of the loss tangent tanδ at a temperature of 200°C is tanδ 200 When this is the case, the temperature dependence of the loss tangent, tanδ, is given by the following formula (A): TD Calculate.

number

[0058] When the copolymerized organopolysiloxane represented by the structural formula (2) is used as the component (a), the siloxane has a vinyl group on its side chain, which develops a crosslinked structure of the silicone rubber and provides stable viscoelasticity, resulting in a low tanδ TD is -4.0×10 -4 On the other hand, if the copolymerized organopolysiloxane represented by the structural formula (2) is not used as the component (a), the siloxane does not have a vinyl group in the side chain, so the crosslinked structure of the silicone rubber does not develop, and tanδ TD is -4.0×10 -4 It will be less than that.

[0059] [About H1 / H0] As mentioned above, when H1 / H0 is 1.2 or more, it is believed that a sufficient amount of vinyl groups remain in the silicone rubber. The cation represented by the structural formula (1) strongly interacts with the silicone rubber, suppressing its migration to the electrode during long-term application of current, which is thought to suppress an increase in resistance.

[0060] Specifically, H1 / H0 can be evaluated by the following method. A plurality of samples (20 mm long, 20 mm wide) are prepared by cutting out from the elastic layer 22 of the electrophotographic member. The cut-out samples are stacked to a thickness of 2 mm. The micro rubber hardness of this stack is measured using a micro rubber hardness tester (product name: Micro Rubber Hardness Tester MD-1 Capa Type C; manufactured by Kobunshi Keiki Co., Ltd.). The measured value at this time is designated as H0.

[0061] Next, all of the samples that constituted the laminate were completely immersed in methyl hydrogen silicone oil (trade name: DOW CORNING TORAY SH1107FLUID; manufactured by Dow Corning Toray Co., Ltd.). The methyl hydrogen silicone oil was maintained at a temperature of 30°C and allowed to stand for 24 hours. This allowed the methyl hydrogen silicone oil to penetrate deep into each sample.

[0062] Next, all samples were removed from the methyl hydrogen silicone oil, the oil on the surface was thoroughly removed, and they were heated in an oven at 200°C for 4 hours, and then cooled to room temperature, which allowed the addition reaction between the remaining vinyl groups in the silicone rubber and the methyl hydrogen silicone oil to be completed for all samples.

[0063] Next, all the samples are laminated again, and the microhardness of the resulting laminate is measured using the above-mentioned device. The microhardness at this point is designated as H1. Then, H1 / H0 is calculated. If there is a large amount of vinyl group remaining in the silicone rubber, new crosslinking points will be formed within the sample due to the methyl hydrogen silicone oil that has permeated into the interior of the sample. Therefore, the hardness of the sample after heat treatment will increase.

[0064] On the other hand, if the amount of vinyl groups remaining in the silicone rubber is small, new crosslinks are unlikely to form even if the sample is impregnated with methyl hydrogen silicone oil and then subjected to heat treatment, and therefore the hardness of the sample after heat treatment hardly increases.

[0065] In this measurement, H0 is preferably 70 degrees or more and 85 degrees or less, and more preferably 75 degrees or more and 80 degrees or less. When H0 is 70 degrees or more, the silicone rubber has sufficient strength and therefore sufficient durability as an electrophotographic member. When H0 is 85 degrees or less, the silicone rubber has good conformability to the unevenness of the paper, thereby improving transferability. The experiment for calculating H1 / H0 is not limited to the above conditions, as long as the vinyl groups remaining in the silicone rubber sample can be reliably reacted.

[0066] [Primer layer] In the electrophotographic member of the present invention, a primer layer (not shown) may be provided between the base layer 21 and the elastic layer 22 to improve adhesion, if necessary. The primer used here is a coating material in which a silane coupling agent, a silicone polymer, a hydrogenated methylsiloxane, an alkoxysilane, a reaction-accelerating catalyst, and a colorant such as red iron oxide are appropriately blended and dispersed in an organic solvent.

[0067] The primer can be appropriately selected depending on the material of the base layer 21, the type of elastic layer 22, or the form of crosslinking reaction. For example, DY39-051A / B or DY39-067A / B manufactured by Dow Corning Toray Co., Ltd. can be used as the primer. The thickness of the primer layer is preferably 0.1 μm or more and 3 μm or less from the viewpoint of reducing cohesive failure within the primer layer.

[0068] [Surface layer] Next, the surface layer 23 in the present invention will be described. The electrophotographic member of the present invention has the surface layer 23. The surface layer 23 is a layer for preventing toner and external additives from adhering to the surface of the electrophotographic member. There are no particular restrictions on the resin used for the surface layer 23 as long as it has low adhesion, and examples thereof include fluororesin, fluorine-containing urethane resin, fluororubber, and siloxane-modified polyimide. Among these, fluororubber is preferred from the viewpoint of not impairing the elastic function of the elastic layer 22.

[0069] The thickness of the surface layer 23 is preferably 3 μm or more and 15 μm or less, more preferably 5 μm or more and 10 μm or less, so as not to impair the flexibility of the elastic layer 22. In order to improve the adhesion between the elastic layer 22 and the surface layer 23, the outer peripheral surface of the elastic layer 22 may be surface-treated. Examples of the surface treatment method include corona discharge and excimer UV irradiation.

[0070] <Application example> An application example of the present invention is an electrophotographic image forming apparatus. The electrophotographic image forming apparatus of the present invention comprises an intermediate transfer belt including the electrophotographic member of the present invention and an image carrier that carries a toner image. The following description will be given.

[0071] [Image forming equipment] An example of an image forming apparatus using the elastic intermediate transfer belt of the present invention will be described with reference to Fig. 1. The electrophotographic image forming apparatus 100 in Fig. 1 is a color electrophotographic image forming apparatus (color laser printer). In this electrophotographic image forming apparatus, image forming units Py, Pm, Pc, and Pk of the respective colors of yellow (Y), magenta (M), cyan (C), and black (K) are arranged in this order in the moving direction along a flat portion of an intermediate transfer belt 7 (an intermediate transfer belt including an electrophotographic member of the present invention) which is an intermediate transfer member.

[0072] Here, 1Y, 1M, 1C, and 1K respectively represent electrophotographic photosensitive members, 2Y, 2M, 2C, and 2K respectively represent charging rollers, 3Y, 3M, 3C, and 3K respectively represent laser exposure devices, 4Y, 4M, 4C, and 4K respectively represent developers, and 5Y, 5M, 5C, and 5K respectively represent primary transfer rollers. Since the basic configuration of each image forming unit is the same, details of the image forming units will only be described for the yellow image forming unit Py.

[0073] The yellow image forming unit Py has a drum-shaped electrophotographic photosensitive member 1Y (hereinafter also referred to as "photosensitive drum" or "first image carrier") as an image carrier. The photosensitive drum 1Y is formed by laminating a charge generation layer, a charge transport layer, and a surface protection layer in this order on an aluminum cylinder as a base.

[0074] The yellow image forming unit Py also includes a charging roller 2Y as a charging means. By applying a charging bias to the charging roller 2Y, the surface of the photosensitive drum 1Y is uniformly charged.

[0075] A laser exposure device 3Y is disposed above the photosensitive drum 1Y as an image exposure means. The laser exposure device 3Y scans and exposes the uniformly charged surface of the photosensitive drum 1Y in accordance with image information, forming an electrostatic latent image of a yellow color component on the surface of the photosensitive drum 1Y.

[0076] The electrostatic latent image formed on the photosensitive drum 1Y is developed with toner, which is a developer, by a developing device 4Y serving as a developing means. That is, the developing device 4Y includes a developing roller 4Ya, which is a developer carrier, and a regulating blade 4Yb, which is a developer amount regulating member, and also contains yellow toner, which is a developer. The developing roller 4Ya, to which the yellow toner is supplied, is lightly pressed against the photosensitive drum 1Y in the developing section, and rotates in the forward direction with a speed difference from the photosensitive drum 1Y. The yellow toner transported to the developing section by the developing roller 4Ya adheres to the electrostatic latent image formed on the photosensitive drum 1Y by applying a developing bias to the developing roller 4Ya. As a result, a visible image (yellow toner image) is formed on the photosensitive drum 1Y.

[0077] The intermediate transfer belt 7 is stretched over a drive roller 71, a tension roller 72, and a driven roller (secondary transfer inner roller) 73, and is moved (rotationally driven) in the direction of the arrow in the figure by contacting the photosensitive drum 1Y, and is cleaned by the transfer belt cleaning unit 11. The yellow toner image formed on the photosensitive drum (first image carrier) that has reached the primary transfer section Ty is primarily transferred onto the intermediate transfer belt 7 by the primary transfer body (primary transfer roller 5Y) that is arranged opposite the photosensitive drum 1Y via the intermediate transfer belt 7.

[0078] Similarly, the above image formation operation is performed in each of the magenta (M), cyan (C), and black (K) units Pm (including primary transfer unit Tm), Pc (including primary transfer unit Tc), and Pk (including primary transfer unit Tk) as the intermediate transfer belt 7 moves, resulting in a four-color toner image of yellow, magenta, cyan, and black being layered on the intermediate transfer belt 7. The four color toner layers are transported along the movement of the intermediate transfer belt 7, and at the secondary transfer unit T', they are transferred together onto the transfer material S (hereinafter also referred to as the "second image carrier"), which is transported at a predetermined timing, by the outer secondary transfer roller 8 serving as secondary transfer means. In this type of secondary transfer, a transfer voltage of several kV is typically applied to ensure a sufficient transfer rate.

[0079] The transfer material S is supplied to a conveying path by a pickup roller 13 from a paper feed cassette 12 in which the transfer material S is stored. The transfer material S supplied to the conveying path is conveyed to a secondary transfer portion T' in synchronization with the four-color toner image transferred to the intermediate transfer belt 7 by a conveying roller pair 14 and a registration roller pair 15.

[0080] The toner image transferred to the transfer material S is fixed by a fixing device 9 to become, for example, a full-color image. The fixing device 9 has a fixing roller 91 equipped with a heating means and a pressure roller 92, and fixes the unfixed toner image on the transfer material S by applying heat and pressure. Thereafter, the transfer material S is discharged outside the apparatus by a pair of conveying rollers 16, a pair of discharging rollers 17, etc.

[0081] A cleaning unit for the intermediate transfer belt 7 is disposed downstream of the secondary transfer portion T' in the driving direction of the intermediate transfer belt 7, and removes the residual toner that has not been transferred to the transfer material S at the secondary transfer portion T' and remains on the intermediate transfer belt 7.

[0082] As described above, the electrical transfer process of the toner image is repeated from the photosensitive member to the intermediate transfer belt and from the intermediate transfer belt to the transfer material. Furthermore, by repeating recording onto multiple transfer materials, the electrical transfer process is further repeated. [Example]

[0083] The present invention will be described in more detail below using examples and comparative examples. The present invention is not limited to the following examples without departing from the gist of the present invention. In the following examples, "parts" are by mass unless otherwise specified.

[0084] [Synthesis of ionic conductive agent 1] Ion conductive agent 1 was synthesized by the following method. 1-Allyl-3-methylimidazolium chloride (7.93 g, manufactured by Tokyo Chemical Industry Co., Ltd.), lithium bis(fluorosulfonyl)imide (9.35 g, manufactured by Tokyo Chemical Industry Co., Ltd.), and pure water (30 mL) were added to a reaction vessel and stirred at room temperature for 18 hours. After stirring, ethyl acetate (manufactured by Kishida Chemical Co., Ltd.) was added and the mixture was separated. The organic layer was washed with water and saturated saline and concentrated to obtain ion conductive agent 1 in an 86% yield.

[0085] [Production of intermediate transfer belt] Example 1 (base layer) An endless polyimide belt with an inner diameter of 370 mm, a width of 370 mm, and a thickness of 80 μm was prepared as the base layer. After irradiating the outer surface of the base layer with excimer UV, a primer (product name: DY39-051A / B, manufactured by Dow Corning Toray Co., Ltd.) was applied and heated at 160°C for 10 minutes.

[0086] (elastic layer) 4.0 parts of ionic conductive agent 1, 70 parts of a copolymeric organopolysiloxane represented by structural formula (2) as component (a) (trade name: VDT-431, manufactured by Gelest Co., Ltd., weight-average molecular weight: 28,000, unsaturated aliphatic group equivalent: 0.61 eq / kg), and 7.5 parts of a copolymeric organopolysiloxane represented by structural formula (3) as component (b) (trade name: HMS-301, manufactured by Gelest Co., Ltd., weight-average molecular weight: 2,000, active hydrogen group equivalent: 2.0 eq / kg) were mixed to obtain mixture 1. At this time, the H / Vi ratio in the mixture was 0.71, and the total amount of cations and anions per 100 parts by mass of silicone rubber was 5.2 parts by mass.

[0087] Next, 30 parts of magnesium hydroxide (trade name: KISMA 5P, manufactured by Kyowa Chemical Industry Co., Ltd.) as a flame retardant, 0.05 parts of a platinum compound (trade name: SIP6829.2, manufactured by Gelest Co., Ltd.) as component (C), and 0.05 parts of 1-ethynyl-1-cyclohexanol (manufactured by Tokyo Chemical Industry Co., Ltd.) as a retarder were mixed, and the mixture was stirred and degassed using a stirring and degassing device (trade name: HM-500, manufactured by Keyence Corporation) to prepare coating solution 1 for elastic layer.

[0088] Next, the polyimide endless belt that would become the base layer was attached to a cylindrical core, and a ring nozzle for discharging rubber was attached coaxially with the core. The elastic layer coating liquid was supplied to the ring nozzle using a liquid feed pump and discharged through the slit, thereby coating the base layer with the elastic layer coating liquid. The relative movement speed and the discharge rate of the liquid feed pump were adjusted so that the cured elastic layer would have a thickness of 250 μm, forming a coating film. The belt attached to the core was placed in a heating furnace and heated at 180°C for 10 minutes to cure the coating film. After cooling, the belt was removed from the core, yielding a laminated belt of the base layer and elastic layer.

[0089] (Surface treatment of elastic layer) The surface of the elastic layer was treated using an excimer UV irradiation unit, an excimer lamp (manufactured by MDCOM) that emits a single wavelength of 172 nm. The belt with the above-mentioned elastic layer laminated thereon was fitted into a cylindrical core, and irradiation was carried out for 30 minutes in a space filled with nitrogen gas and air while the core was rotated at a rotation speed of 5 rpm from a distance of approximately 1 mm from the surface of the excimer UV lamp.

[0090] (Surface layer) Coating solution 1 for the surface layer was prepared by mixing 100 parts of a fluororubber paint (product name: Dai-el Latex GLS-213CRRA, solid content 50 wt%, manufactured by Daikin Industries, Ltd.) and 5 parts of a curing agent containing an amine-based vulcanizing agent (product name: Dai-el Latex GL-200RB, solid content 35 wt%, manufactured by Daikin Industries, Ltd.).

[0091] Next, the surface layer coating liquid was sprayed onto the elastic layer so that the thickness of the surface layer after drying would be 7 μm, and the belt was placed in a heating furnace while attached to the core and heated at 200°C for 15 minutes to harden the coating, thereby producing an intermediate transfer belt with a surface layer formed on the elastic layer.

[0092] [tanδ TD Measurement of The base layer and the surface layer were removed from the prepared intermediate transfer belt to obtain an elastic layer. The elastic layer was cut into a size of 10 mm in length, 5 mm in width, and 250 μm in thickness, and set in a tensile measurement attachment of a dynamic viscoelasticity measuring device (trade name: Rheogel-E4000; manufactured by UBM). The loss tangent tanδ was measured at 50°C and 200°C at a vibration frequency of 10 Hz, and the temperature dependence of the loss tangent tanδ was calculated using the above formula (A). TD was calculated.

[0093] [H1 / H0 measurement] The base layer and surface layer were removed from the prepared intermediate transfer belt to obtain an elastic layer. Eight pieces of the elastic layer, each measuring 20 mm in length, 20 mm in width, and 250 μm in thickness, were cut out. The cut-out samples were then stacked to a thickness of 2 mm, and the micro hardness (H0) of this laminate was measured using a Type C micro hardness tester (product name: Micro Hardness Tester MD-1 capa Type C; manufactured by Kobunshi Keiki Co., Ltd.).

[0094] All samples constituting the laminate were placed in a container containing 50 mL of methyl hydrogen silicone oil (trade name: DOW CORNING TORAY SH 1107 FLUID; manufactured by Dow Corning Toray Co., Ltd.) and immersed until completely submerged. The samples were then placed in a water bath set at 30°C for 24 hours. The samples were then removed from the methyl hydrogen silicone oil, and the oil on the surface of each sample was thoroughly wiped off with a wiper (trade name: Kimwipe S-200; manufactured by Nippon Paper Crecia Co., Ltd.). Each sample was then placed in an oven set at 200°C and heated for 4 hours, after which it was cooled to room temperature. The samples were then removed from the oven, re-laminated, and the micro rubber hardness (H1) of the laminate was measured in the same manner as above (for H0). H1 / H0 was calculated from the obtained micro rubber hardnesses H0 and H1.

[0095] Example 2 An intermediate transfer belt was produced in the same manner as in Example 1, except that the ionic conductive agent 1 in the coating liquid for the elastic layer was changed to the ionic conductive agent 5.

[0096] Example 3 An intermediate transfer belt was produced in the same manner as in Example 1, except that the ionic conductive agent 1 in the coating liquid for the elastic layer was changed to the ionic conductive agent 4.

[0097] Example 4 An intermediate transfer belt was produced in the same manner as in Example 3, except that the amount of ionic conductive agent 4 in the coating liquid for the elastic layer was changed from 4.0 parts to 0.25 parts. In this case, the total amount of cations and anions per 100 parts by mass of silicone rubber was 0.32 parts by mass.

[0098] Example 5 An intermediate transfer belt was produced in the same manner as in Example 3, except that the amount of ionic conductive agent 4 in the coating liquid for the elastic layer was changed from 4.0 parts to 0.4 parts. In this case, the total amount of cations and anions per 100 parts by mass of silicone rubber was 0.52 parts by mass.

[0099] Example 6 An intermediate transfer belt was produced in the same manner as in Example 3, except that the amount of ionic conductive agent 4 in the coating liquid for the elastic layer was changed from 4.0 parts to 7.5 parts. In this case, the total amount of cations and anions per 100 parts by mass of silicone rubber was 9.7 parts by mass.

[0100] Example 7 An intermediate transfer belt was produced in the same manner as in Example 3, except that the amount of ionic conductive agent 4 in the coating liquid for the elastic layer was changed from 4.0 parts to 9.0 parts. In this case, the total amount of cations and anions per 100 parts by mass of silicone rubber was 11.6 parts by mass.

[0101] Example 8 An intermediate transfer belt was produced in the same manner as in Example 1, except that the copolymerized organopolysiloxane represented by structural formula (2) in the elastic layer coating liquid was changed to the following, and the copolymerized organopolysiloxane represented by structural formula (3) was changed from 7.5 parts to 12.5 parts, In this case, the H / Vi ratio in the mixture was 0.71, and the total amount of cations and anions per 100 parts by mass of silicone rubber was 4.8 parts by mass. Copolymerized organopolysiloxane represented by structural formula (2) used in Example 8: (Product name: VDT-731, manufactured by Gelest, weight average molecular weight 28000, unsaturated aliphatic group equivalent 1.0eq / kg)

[0102] Example 9 An intermediate transfer belt was produced in the same manner as in Example 1, except that the copolymerized organopolysiloxane represented by structural formula (2) in the elastic layer coating liquid was changed to the following, and the copolymerized organopolysiloxane represented by structural formula (3) was changed from 7.5 parts to 1.8 parts, In this case, the H / Vi ratio in the mixture was 0.72, and the total amount of cations and anions per 100 parts by mass of silicone rubber was 5.6 parts by mass. Copolymerized organopolysiloxane represented by structural formula (2) used in Example 9: (Product name: VDT-131, manufactured by Gelest, weight average molecular weight 28000, unsaturated aliphatic group equivalent 0.14eq / kg)

[0103] Example 10 An intermediate transfer belt was produced in the same manner as in Example 3, except that the copolymerized organopolysiloxane represented by structural formula (3) in the elastic layer coating liquid was changed from 7.5 parts to 5.5 parts. At this time, the H / Vi ratio in the mixture was 0.52, and the total amount of cations and anions per 100 parts by mass of silicone rubber was 5.3 parts by mass.

[0104] Example 11 An intermediate transfer belt was produced in the same manner as in Example 3, except that the copolymerized organopolysiloxane represented by structural formula (3) in the elastic layer coating liquid was changed from 7.5 parts to 9.5 parts. At this time, the H / Vi ratio in the mixture was 0.89, and the total amount of cations and anions per 100 parts by mass of silicone rubber was 5.0 parts by mass.

[0105] (Comparative Example 1) An intermediate transfer belt was produced in the same manner as in Example 1, except that the ionic conductive agent 1 in the coating liquid for the elastic layer was changed to 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (manufactured by Tokyo Chemical Industry Co., Ltd.).

[0106] (Comparative Example 2) An intermediate transfer belt was produced in the same manner as in Example 1, except that the copolymerized organopolysiloxane represented by structural formula (2) in the elastic layer coating liquid was changed to the following, and the copolymerized organopolysiloxane represented by structural formula (3) was changed from 7.5 parts to 0.9 parts, In this case, the H / Vi ratio in the mixture was 0.72, and the total amount of cations and anions per 100 parts by mass of silicone rubber was 5.6 parts by mass. Organopolysiloxane used in Comparative Example 2: (Product name: DMS-V31, manufactured by Gelest, weight average molecular weight 28,000, unsaturated aliphatic group equivalent weight 0.071 eq / kg)

[0107] (Comparative Example 3) An intermediate transfer belt was produced in the same manner as in Example 1, except that the copolymerized organopolysiloxane represented by structural formula (3) in the elastic layer coating liquid was changed from 7.5 parts to 11.0 parts. At this time, the H / Vi ratio in the mixture was 1.04, and the total amount of cations and anions per 100 parts by mass of silicone rubber was 4.9 parts by mass. Tan δ of the intermediate transfer belts shown in Examples 1 to 11 and Comparative Examples 1 to 3 TD , H1 / H0 are shown in Table 2.

[0108] [Table 2]

[0109] [evaluation] In the present examples, the volume resistivity was measured by the following method. <Volume resistivity measurement method> Measurements were performed using a double-electrode method with a high resistivity meter (product name: Hiresta UP MCP-HT450, manufactured by Mitsubishi Chemical Analytech Co., Ltd.) under an environment of normal temperature and humidity (temperature 25°C, relative humidity 50%). A UR probe was placed in contact with the outer surface of the surface layer, and the volume resistivity value measured at an applied voltage of 1000 V and a measurement time of 10 seconds was taken as the measured value. Measurements were performed at four points every 90° in the circumferential direction of the surface layer, and the average of these measurements was calculated.

[0110] (resistance increase evaluation) First, the volume resistivity of the intermediate transfer belt was measured by the above-described volume resistivity measurement method, and the initial volume resistivity measurement value was designated as ρv0. Next, the intermediate transfer belt was installed as an intermediate transfer belt in an electrophotographic image forming apparatus (product name: imagePRESS C800, manufactured by Canon Inc.), and 500,000 sheets of A4-sized plain paper were passed through the belt in an environment of normal temperature and humidity (temperature 25°C, relative humidity 50%).

[0111] After passing 500,000 sheets, the intermediate transfer belt was removed from the electrophotographic image forming apparatus and its volume resistivity was measured by the volume resistivity measurement method described above. The measured value of the volume resistivity after passing 500,000 sheets was designated as ρv1.

[0112] Using the measured volume resistivities ρv0 and ρv1, log 10 (ρv1 / ρv0) was calculated and used as a value representing the increase in resistance. In the present invention, log 10 If (ρv1 / ρv0) is less than 1.0, it is determined that there is no problem with resistance increase during long-term use.

[0113] (Initial transferability evaluation) The intermediate transfer belt before paper feeding was installed as the intermediate transfer belt of the electrophotographic image forming apparatus, and A4 size embossed paper (trade name: Lezac 66 250 g / m) was printed under normal temperature and humidity (temperature 25°C, relative humidity 50%). 2 A full-surface secondary color solid image of cyan and magenta was formed on a sheet of paper (manufactured by Tokushu Tokai Seishi Co., Ltd.).

[0114] The resulting images were evaluated according to the following criteria. Rank A: No image unevenness is observed and it is good. Rank B: Slight image unevenness in some of the embossed paper recesses Rank C: Image unevenness in about 20% of the embossed paper recesses Rank D: Image unevenness over more than half of the embossed paper recesses In the present invention, in the cases of ranks A to C, it was determined that there was no problem with the initial transferability. Table 3 shows the evaluation results of the intermediate transfer belts produced in Examples 1 to 11 and Comparative Examples 1 to 3.

[0115] [Table 3] As a result of the evaluation, in the example, there was no problem with the increase in resistance during long-term use, whereas in the comparative examples 1 to 3, there was a problem with the increase in resistance during long-term use.

[0116] The disclosure of this embodiment includes the following configuration. (Configuration 1) 1. An electrophotographic member having, in order, a base layer, an elastic layer, and a surface layer, The elastic layer contains silicone rubber, a cation represented by the following structural formula (1), and an anion, the anion is a bis(fluorosulfonyl)imide anion, The loss tangent of the elastic layer at a temperature of 50°C is tanδ 50 The loss tangent of the elastic layer at a temperature of 200°C is tanδ 200 When this is the case, the temperature dependence of the loss tangent, tanδ, is given by the following formula (A): TD But -4.0×10 -4 is greater than or equal to 0 and less than or equal to wherein H1 / H0 is 1.2 or more and 1.9 or less, where H0 is the hardness of the elastic layer measured with a micro rubber hardness tester, and H1 is the hardness of the elastic layer measured with a micro rubber hardness tester after immersing the elastic layer in methyl hydrogen silicone oil for 24 hours and curing the elastic layer. [ka] (In structural formula (1), R 1 and R 2 are each independently a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, provided that R 1 and R 2 At least one of the groups is a group having at least one alkenyl group.

number

[0117] Py: Yellow image forming unit Pm: Magenta image forming unit Pc: Cyan image forming unit Pk: Black image forming unit 1Y: Yellow photosensitive drum 1M: Magenta photosensitive drum 1C: Cyan photosensitive drum 1K: Black photosensitive drum 4Y: Yellow developer 4M: Magenta developer 4C: Cyan developer 4K: Black developer 5Y, 5M, 5C, 5K: Primary transfer roller Ty, Tm, Tc, Tk: Primary transfer section 73: Secondary transfer inner roller 100: Image forming device 2Y, 2M, 2C, 2K: Charging roller 3Y, 3M, 3C, 3K: Laser exposure equipment 11: Transfer belt cleaning unit 12: Paper cassette 15: Registration roller pair 7: Intermediate transfer belt 8: Secondary transfer outer roller 9: Fixing unit 91: Fuser roller 92: Pressure roller S: Transfer material 21: Base layer 22: Elastic layer 23: Surface layer

Claims

1. 1. An electrophotographic member having, in order, a base layer, an elastic layer, and a surface layer, The elastic layer contains silicone rubber, a cation represented by the following structural formula (1), and an anion, the anion is a bis(fluorosulfonyl)imide anion, The loss tangent of the elastic layer at a temperature of 50°C is tanδ ５０ The loss tangent of the elastic layer at a temperature of 200°C is tanδ ２００ When the temperature dependence of the loss tangent (tanδ) is ＴＤ But -4.0 x 10 －４ is greater than or equal to 0 and less than or equal to The hardness of the elastic layer measured with a micro rubber hardness meter is H ０ The elastic layer was immersed in methyl hydrogen silicone oil for 24 hours and cured. After that, the hardness of the elastic layer was measured with a micro rubber hardness meter. １ When this is done, H １ / H ０ is 1.2 or more and 1.9 or less. 【number】 (In structural formula (1), R １ and R ２ are each independently a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, provided that R １ and R ２ At least one of the groups is a group having at least one alkenyl group. [Equation 1]

2. 2. An electrophotographic member according to claim 1, wherein said group having an alkenyl group is an allyl group.

3. The R １ and the R ２ 2. The electrophotographic member of claim 1 wherein is an allyl group.

4. 2. The electrophotographic member according to claim 1, wherein the total amount of the cations and the anions is 0.5 parts by mass or more and 10.0 parts by mass or less when the mass of the silicone rubber is 100 parts by mass.

5. The tan δ ＴＤ But -4.0 x 10 －４ Above -1.0 x 10 －４ 2. The electrophotographic member of claim 1 wherein:

6. 1. An electrophotographic member having, in order, a base layer, an elastic layer, and a surface layer, The elastic layer is (A) a cation represented by the following structural formula (1): (B) bis(fluorosulfonyl)imide anion, (C) a copolymerized organopolysiloxane represented by the following structural formula (2): (D) a copolymerized organopolysiloxane represented by the following structural formula (3): A cured product of a mixture comprising The electrophotographic member is characterized in that the ratio of the number of Si-H groups to the number of Si-vinyl groups (H / Vi) in the mixture is 0.5 or more and 0.9 or less. 【Chemistry 2】 (In structural formula (1), R １ and R ２ are each independently a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, provided that R １ and R ２ At least one selected from the group consisting of is a group having at least one alkenyl group. 【Transformation 3】 (In structural formula (2), m １ and m ２ are each an integer of 1 or more, and R ３ is a methyl group or a vinyl group. 【Chemistry 4】 (In structural formula (3), n １ and n ２ are each an integer of 1 or greater.)

7. 7. The electrophotographic member according to claim 6, wherein the total amount of (A) and (B) in the mixture is 0.5 parts by mass or more and 10.0 parts by mass or less when the total amount of (C) and (D) in the mixture is 100 parts by mass.

8. 8. An electrophotographic image forming apparatus comprising an intermediate transfer belt including the electrophotographic member according to claim 1, and an image carrier that carries a toner image.

Images