Conductive elastic roller, process cartridge, and electrophotographic image forming apparatus

Abstract

A conductive elastic roller that enables high-quality image formation over a long period of time, even when applied to electrophotographic image formation processes. [Solution] A conductive elastic roller having a conductive substrate and a conductive elastic layer on the substrate, wherein the conductive elastic layer comprises polyurethane and carbon nanotubes, and the polyurethane comprises a nitrogen-containing heteroaromatic ring structure.

Description

[Technical Field]

[0001] This disclosure relates to conductive elastic rollers, process cartridges, and electrophotographic image forming apparatus used in electrophotographic systems. [Background technology]

[0002] Conductive elastic rollers are used in electrophotographic image forming apparatuses as charging members, transfer members, developing members, developer supply members, etc. One known form of conductive elastic roller has a conductive support and a conductive layer provided on the support. This conductive elastic roller transports electric charge from the conductive support to the surface of the conductive elastic roller and imparts charge to the object in contact with it by discharge or triboelectric charging.

[0003] The conductive elastic rollers used as these components need to provide a stable charge supply over a long period of time to the contacting objects, such as electrophotographic photoreceptors, developers, intermediate transfer media, and printing media. Patent Document 1 discloses a conductive member that incorporates carbon nanotubes (CNTs) as a conductive agent, thereby reducing electrical resistance with a small amount of CNTs and maintaining contact with the object being in contact with due to its low hardness and flexibility. Patent documents 2 and 3 disclose a technique for incorporating CNTs and ionic liquids into the base resin of an electrophotographic component. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2004-101958 [Patent Document 2] Japanese Patent Publication No. 2005-220316 [Patent Document 3] Japanese Patent Publication No. 2015-203806 [Overview of the project] [Problems that the invention aims to solve]

[0005] Electrophotographic image forming apparatuses are required to stably form excellent electrophotographic images even under harsh environments. According to the inventors' studies, the conductive member described in Patent Document 1 sometimes showed an increase in electrical resistance during use. The electrophotographic members described in Patent Documents 2 and 3 also showed an increase in electrical resistance during long-term use.

[0006] This disclosure relates to a conductive elastic roller that enables high-quality image formation over a long period of time, even when applied to an electrophotographic image formation process. Furthermore, this disclosure relates to a process cartridge that enables high-quality image formation over a long period of time. Moreover, this disclosure relates to an electrophotographic image forming apparatus that enables high-quality image formation over a long period of time. [Means for solving the problem]

[0007] This disclosure relates to a conductive elastic roller having a conductive substrate and a conductive elastic layer on the substrate, The conductive elastic layer comprises polyurethane and carbon nanotubes. The present invention relates to a conductive elastic roller in which the polyurethane contains a nitrogen-containing heteroaromatic ring structure.

[0008] Furthermore, this disclosure relates to a process cartridge that is detachably configured to be attached to the main body of an electrophotographic image forming apparatus, and which comprises the conductive elastic roller described above. .

[0009] Furthermore, this disclosure relates to an electrophotographic image forming apparatus comprising the conductive elastic roller described above. [Effects of the Invention]

[0010] According to one aspect of the present disclosure, it is possible to provide a conductive elastic roller that enables high-quality image formation over a long period even when applied to an electrophotographic image forming process. Further, according to another aspect of the present disclosure, it is possible to provide a process cartridge and an electrophotographic image forming apparatus that enable high-quality image formation over a long period.

Brief Description of the Drawings

[0011] [Figure 1] FIG. 1 is a schematic diagram showing one form of a conductive elastic roller. [Figure 2] FIG. 2 is a schematic cross-sectional view showing an example of an electrophotographic image forming apparatus. [Figure 3] FIG. 3 is a schematic cross-sectional view showing an example of a process cartridge. [Figure 4] FIGS. 4A and 4B show schematic configuration diagrams of a jig for evaluating resistance values.

Modes for Carrying Out the Invention

[0012] In the present disclosure, the description of "XX or more and YY or less" or "XX to YY" representing a numerical range means a numerical range including the lower limit and the upper limit which are the endpoints, unless otherwise specified. When numerical ranges are described stepwise, the upper and lower limits of each numerical range can be arbitrarily combined. Further, in the present disclosure, a description such as "at least one selected from the group consisting of XX, YY, and ZZ" means any one of XX, YY, ZZ, a combination of XX and YY, a combination of XX and ZZ, a combination of YY and ZZ, or a combination of XX, YY, and ZZ. Note that when XX is a group, a plurality may be selected from XX, and the same applies to YY and ZZ.

[0013] Also, in this specification, for convenience of explanation, there are cases where a carbon nanotube is described as a carbon nanotube as it is and cases where it is abbreviated as CNT, but they are not distinguished.

[0014] The inventors of the present invention have speculated as follows on the reason why the electrical resistance value of the conductive member according to Patent Document 1 increased during use. In CNT, π-orbital electrons on a certain molecule are easily adsorbed to π-orbital electrons on other molecules by π-π interaction, and aggregates ranging from several to tens of thousands are easily formed. Therefore, when mixing CNT, large aggregates will surely occur if measures for suppressing aggregate formation and dissociating aggregated CNT are not included.

[0015] In a conductive member made of a resin in which CNT is dispersed, when CNT aggregates are mixed, due to the high conductivity of CNT itself, excessive charge transfer occurs locally near the CNT aggregates during energization, and a large electrostatic force due to electric field concentration is applied to the CNT. When this is repeated, movement of CNT in the resin, outflow to the surface, and detachment of CNT occur. Since the detachment of CNT causes the conductive member to have a high resistance, this phenomenon occurs in the conductive member according to Patent Document 1, and it is considered that the electrical resistance value has increased.

[0016] In addition, the inventors of the present invention have speculated as follows on the reason why the electrical resistance value of the conductive members according to Patent Documents 2 and 3 increased during long-term use. When mixing carbon nanotubes that are likely to aggregate, it is necessary to suppress aggregation and defibrate the aggregates. Although it is difficult to completely prevent the generation of aggregates, various measures have been taken to improve the dispersibility of CNT.

[0017] In Patent Documents 2 and 3, a process of dispersing CNT in a resin is carried out by utilizing the affinity between an ionic liquid and CNT. Adsorption occurs due to the π-π interaction between the π-orbital electrons in the nitrogen-containing heteroaromatic ring structure of the cation component of the ionic liquid and the π-orbital electrons on CNT. By utilizing this action to improve the dispersibility of CNT in the resin and adsorbing the ionic liquid and CNT in the resin, it may be possible to temporarily relieve the movement and detachment of CNT.

[0018] However, when an electric current is applied, the cations or anions of the ionic liquid move in response to the applied electric field, and eventually the ionic components near the CNTs disappear, so the affinity effect is finite. Due to improved dispersibility, even when the existing CNT aggregates are relatively small, it is thought that prolonged use (electrical current) causes CNT movement and outflow to the surface due to electric field concentration, and ultimately CNT desorption, leading to an increase in electrical resistance.

[0019] Based on these considerations, the inventors investigated the molecular structure of polyurethane containing carbon nanotubes (CNTs) in order to solve the problem of the increase in electrical resistance over time when conductive members in the prior art are used. As a result, they found that a conductive elastic roller equipped with a conductive elastic layer containing polyurethane that satisfies the following requirements can effectively solve the above problem.

[0020] The conductive elastic roller of this disclosure comprises a conductive substrate and a conductive elastic layer on the substrate. The conductive elastic layer comprises polyurethane and carbon nanotubes, wherein the polyurethane comprises a nitrogen-containing heteroaromatic ring structure.

[0021] In the conductive elastic layer, carbon nanotubes (CNTs) can adsorb to the nitrogen-containing heteroaromatic ring structure present in the polyurethane molecular backbone. Due to this adsorption, the CNTs do not move even when electrostatic force is applied during current flow.

[0022] Therefore, even after long-term use, the adsorption of nitrogen-containing heteroaromatic ring structures and CNTs is maintained within the polyurethane resin, and the relative positions of the CNTs within the polyurethane resin do not change. This is thought to suppress CNT desorption and the resulting increase in electrical resistance. Furthermore, because the relative positions of the CNTs within the polyurethane resin do not change, this effect is maintained even if CNT aggregates are formed. This effect is also maintained even when a higher voltage (electric field) than conventional methods is applied.

[0023] <Conductive elastic roller> A conductive elastic roller comprises a conductive substrate and a conductive elastic layer on the substrate. An example of a conductive elastic roller is shown in Figure 1. The conductive elastic roller 1 shown in Figure 1 consists of a conductive substrate 2 and a conductive elastic layer 3 provided on its outer circumference.

[0024] Furthermore, the layer configuration of a conductive elastic roller is not limited to one in which the conductive elastic layer is located on the outermost surface of the conductive elastic roller. A conductive elastic roller may have a surface layer on top of the conductive elastic layer provided on the substrate and its outer circumference. In addition, a conductive elastic roller may have other layers, such as another elastic layer different from the conductive elastic layer, between the substrate and the conductive elastic layer.

[0025] The conductive elastic roller can be used as at least one of a charging roller, a developing roller, a toner supply roller, and a transfer roller in an electrophotographic image forming apparatus. The charging roller generates a discharge between itself and the electrophotographic photoreceptor, charging the surface of the electrophotographic photoreceptor. The developing roller controls the charge of the developer coating its surface by triboelectric charging, providing a uniform charge distribution, and then, according to the applied electric field, the developer is charged to the electrophotographic photoreceptor. The toner is uniformly transferred to the surface. The toner supply roller coats the surface of the developing roller with the developing agent while controlling the charge of the developing agent by triboelectric charging. The transfer roller also transfers the developing agent from the electrophotographic photoreceptor to the printing medium or intermediate transfer medium, and at the same time generates a discharge to stabilize the developed agent after transfer. In particular, the conductive elastic roller is preferably the toner supply roller.

[0026] <Base> The substrate is conductive and functions as a support member and electrode for the conductive elastic roller. The substrate is made of a conductive material such as metal or alloy, such as aluminum, copper alloy, or stainless steel; iron plated with chromium or nickel; or a conductive synthetic resin. For example, the substrate is stainless steel. The substrate is preferably solid or hollow cylindrical.

[0027] <Conductive elastic layer> The conductive elastic layer contains polyurethane and carbon nanotubes, and the polyurethane contains a nitrogen-containing heteroaromatic ring structure. The shape of the conductive elastic layer is not particularly limited, but it is preferable that it adheres to the outer circumference of the substrate in a cylindrical shape. The nitrogen-containing heteroaromatic ring structure contained in polyurethane refers to a structure in which nitrogen, in addition to carbon, constitutes the aromatic ring in the chemical structure.

[0028] Preferably, the nitrogen-containing heteroaromatic ring structure is a cationic structure formed by the nitrogen-containing heteroaromatic ring. That is, it is preferable that the nitrogen-containing heteroaromatic ring structure is a cationic nitrogen-containing heteroaromatic ring structure. Because the nitrogen-containing heteroaromatic ring structure is cationic, it is possible to suppress the increase in electrical resistance over a longer period of time.

[0029] This is due to the electrostatic force acting between the cation and an anion, which is an atom or molecule in close proximity that carries the opposite charge to the cation. The anion in the polyurethane causes the nitrogen-containing heteroaromatic ring structure, which is the cation, to be more constrained within the polyurethane, thus improving the resistance of CNTs adsorbed on the nitrogen-containing heteroaromatic interstructure. Although an electrostatic force is exerted on the cation when electricity is applied, the nitrogen-containing heteroaromatic ring structure, which is the cation, is strongly constrained by its surroundings because it is located within the polyurethane molecule, and therefore does not move.

[0030] The nitrogen-containing heteroaromatic ring structure is preferably at least one cationic nitrogen-containing heteroaromatic ring structure selected from the group consisting of imidazolium cation, pyridinium cation, pyrazinium cation, pyrimidinium cation, azepinium cation, quinolinium cation, isoquinolinium cation, indolinium cation, quinoxalinium cation, triazolium cation, triazinium cation, and thiazolinium cation. More preferably, the nitrogen-containing heteroaromatic ring structure is at least one cationic nitrogen-containing heteroaromatic ring structure selected from the group consisting of imidazolium cation, pyridinium cation, and pyrazinium cation.

[0031] More preferably, the cation structure formed by the nitrogen-containing heteroaromatic ring has at least one cation structure selected from the group consisting of the structure shown in structural formula (1), the structure shown in structural formula (2), and the structure shown in structural formula (3).

[0032] [ka]

[0033] In structural formula (1), R1 and R2 each represent hydrocarbon groups necessary to form a nitrogen-containing heteroaromatic five-membered ring together with the nitrogen atom to which they are bonded, and d1 represents an integer of 0 or 1. Z1 to Z3 each independently represent the structure shown in structural formula (Z101), the structure shown in structural formula (Z102), the structure shown in structural formula (Z103), a hydrogen atom, or a hydrocarbon group having 1 to 4 carbon atoms (preferably 1 to 2, more preferably 1). However, at least one of Z1 to Z3 is the structure shown in structural formula (Z101), the structure shown in structural formula (Z102), or the structure shown in structural formula (Z103).

[0034] Preferably, Z1 and Z2 have structures represented by the following structural formula (Z101). When d1 is 1, Z3 is preferably a hydrocarbon group having 1 to 4 carbon atoms (preferably 1 to 2, more preferably 1). The hydrocarbon group having 1 to 4 carbon atoms is preferably an alkyl group. The nitrogen-containing heteroaromatic structure of formula (1) is preferably, for example, an imidazolium cation.

[0035] [ka]

[0036] In structural formula (2), R3 and R4 each represent hydrocarbon groups necessary to form a nitrogen-containing heteroaromatic six-membered ring together with the nitrogen atom to which they are bonded. d2 represents an integer from 0 to 2, and when d2 is 2, Z5 may be the same or different. Z4 and Z5 each independently represent the structure shown in structural formula (Z101), the structure shown in structural formula (Z102), the structure shown in structural formula (Z103), a hydrogen atom, or a hydrocarbon group having 1 to 4 carbon atoms (preferably 1 to 2, more preferably 1). However, at least one of Z4 and Z5 is the structure shown in structural formula (Z101), the structure shown in structural formula (Z102), or the structure shown in structural formula (Z103). The hydrocarbon group having 1 to 4 carbon atoms is preferably an alkyl group. The nitrogen-containing heteroaromatic structure of formula (2) is preferably, for example, a pyrazinium cation.

[0037] [ka]

[0038] In structural formula (3), R5 represents a hydrocarbon group necessary to form a nitrogen-containing heteroaromatic ring (preferably a 5-membered or 6-membered ring, more preferably a 6-membered ring) together with the bonded nitrogen atom, and d3 represents an integer of 0 or 1. Z6 and Z7 each independently represent the structure shown in structural formula (Z101), the structure shown in structural formula (Z102), the structure shown in structural formula (Z103), a hydrogen atom, or a hydrocarbon group having 1 to 4 carbon atoms (preferably 1 to 2, more preferably 1). However, at least one of Z6 and Z7 is the structure shown in structural formula (Z101), the structure shown in structural formula (Z102), or the structure shown in structural formula (Z103). The hydrocarbon group having 1 to 4 carbon atoms is preferably an alkyl group. The nitrogen-containing heteroaromatic structure of formula (3) is preferably, for example, a pyridinium cation.

[0039] [ka]

[0040] In structural formulas (Z101), (Z102), and (Z103), R101, R102, and R103 each independently represent a divalent hydrocarbon group having a straight chain or branching, the symbol "*" represents a bond with a nitrogen atom or carbon atom constituting a nitrogen-containing heteroaromatic five-membered ring in structural formula (1), a bond with a nitrogen atom or carbon atom constituting a nitrogen-containing heteroaromatic six-membered ring in structural formula (2), or a bond with a nitrogen atom or carbon atom constituting a nitrogen-containing heteroaromatic ring in structural formula (3), and the symbol "**" represents a bond with a carbon atom in the polymer chain of the polyurethane. The divalent hydrocarbon group is preferably a linear or branched alkylene group having 1 to 8 carbon atoms (preferably 1 to 4, more preferably 1 to 2).

[0041] The polyurethane functions as an anion carrier when the nitrogen-containing heteroaromatic ring structure is a cation. Furthermore, the conductive elastic layer may contain a resin other than the resin having a nitrogen-containing heteroaromatic ring structure.

[0042] Conductive elastic rollers having a conductive elastic layer can be used as charging rollers, developing rollers, and transfer rollers, and are particularly suitable for use as toner supply rollers. When used as a toner supply roller, it is preferable that it has a foamed structure with continuous pores inside. Toner supply rollers are required to have the performance to supply toner. In the foamed structure, it is preferable to control characteristics such as the average cell diameter of the surface, the number of cells, the amount of air permeability, and the density of the entire foamed elastic layer.

[0043] The physical properties of the conductive elastic layer having a foamed structure are not particularly limited, but it is preferable that they be within the following numerical ranges, for example: The conductive elastic layer has an average cell diameter of 100 to 500 μm and a cell count of 50 to 300 cells / inch on its surface. 2 It is preferable that the foamed elastic layer has voids.

[0044] The average cell diameter on the surface of the conductive elastic layer is preferably 100 to 500 μm, and more preferably 200 to 400 μm. The number of cells in the conductive elastic layer is preferably 50 to 300 cells / inch. 2 More preferably 70-200 pieces / inch 2 The air permeability of the conductive elastic layer is, for example, 0.5 L / min or more and 3.0 L / min or less. The density of the conductive elastic layer is, for example, 0.05 g / cm³. 3 More than 0.20g / cm 3 The following applies:

[0045] The average cell diameter and number of cells can be controlled, for example, by adjusting the conditions in the manufacturing process of the conductive elastic layer or by adding auxiliary agents as described later.

[0046] <Carbon nanotubes (CNTs)> The conductive elastic layer contains carbon nanotubes (CNTs). CNTs refer to a material in which graphene sheets, consisting of a six-membered ring network of carbon atoms, are formed into single-layer or multi-layer coaxial tubular structures. Generally, CNTs are classified into single-walled CNTs and multi-walled CNTs based on the number of components in the coaxial tubular perimeter wall, and further classified into zigzag, armchair, and chiral types based on differences in the arrangement of carbon atoms, and various structures are known. In this disclosure, any of these CNT structures is applicable. The carbon nanotubes preferably include single-walled carbon nanotubes, and more preferably single-walled carbon nanotubes.

[0047] The number-average length of the carbon nanotubes in the short-side direction is preferably 2.0 to 50.0 nm, and more preferably 4.0 to 40.0 nm. The number average length of the carbon nanotube in the longitudinal direction is preferably 10 to 2000 μm, and more preferably 100 to 500 μm. This is because adsorption between the nitrogen-containing heteroaromatic ring structure and the CNT is more likely to occur when the length in the longitudinal direction relative to the short side, i.e., when the aspect ratio is large.

[0048] <Polyurethane> The polyurethane contained in the conductive elastic layer of the conductive elastic roller contains a nitrogen-containing heteroaromatic ring structure.

[0049] The polyurethane having the nitrogen-containing heteroaromatic ring structure is, for example, a polyurethane having the nitrogen-containing heteroaromatic ring structure It is a reaction product of a compound and a polyurethane raw material mixture that forms polyurethane. The polyurethane raw material mixture includes, for example, compounds other than compounds containing a nitrogen-containing heteroaromatic ring structure (hereinafter also referred to as "nitrogen-containing heteroaromatic ring compound"), preferably a polyol and a polyisocyanate. The nitrogen-containing heteroaromatic ring compound is preferably an ionic compound containing a nitrogen-containing heteroaromatic ring structure which is a cation and an anion.

[0050] The compound containing the nitrogen-containing heteroaromatic ring structure preferably has at least one functional group containing a hydroxyl group, an amino group, or a glycidyl group. The hydroxyl group and amino group react with the isocyanate group of the nitrogen-containing heteroaromatic ring compound to form a bond. Therefore, for example, the nitrogen-containing heteroaromatic ring structure can be introduced into the urethane molecular structure by the reaction of the nitrogen-containing heteroaromatic ring compound with a polyisocyanate. The glycidyl group reacts with the hydroxyl group of the nitrogen-containing heteroaromatic ring compound to form a bond. Therefore, the nitrogen-containing heteroaromatic ring structure can be introduced into the urethane molecular structure by the reaction of the nitrogen-containing heteroaromatic ring compound with a polyol.

[0051] Examples of compounds containing a nitrogen-containing heteroaromatic ring structure include the following compounds that have a nitrogen-containing heteroaromatic ring structure and a hydroxyl group. 1-(2-hydroxyethyl)imidazole, 4(5)-(hydroxymethyl)imidazole, 5-hydroxy-1-methyl-1H-pyrazole, 1-(2-hydroxyethyl)pyrrole, 2-hydroxypyridine, 3-hydroxypyridine, 4-hydroxypyridine, 6-hydroxypyrimidine, 2-hydroxypyrazine, 2,4,6-trihydroxy-1,3,5-triazine, 5-hydroxyindole; and derivatives thereof.

[0052] Compounds having a nitrogen-containing heteroaromatic ring structure and at least one functional group containing an amino group or a glycidyl group are not particularly limited. For example, examples include compounds having a nitrogen-containing heteroaromatic ring structure as exemplified above, in which the hydroxyl group of a compound having a hydroxyl group is replaced with a group containing a glycidyl group or an amino group.

[0053] As already mentioned, the nitrogen-containing heteroaromatic ring structure is preferably a cationic structure, and in this case, the compound having the cation-containing nitrogen-containing heteroaromatic ring structure is an ionic compound. More preferably, the cationic structure is the structure shown in the structural formulas (1) to (3) described above.

[0054] Therefore, compounds containing a nitrogen-containing heteroaromatic ring structure are preferably compounds in which the portion to which the structure shown in structural formula (Z101), structural formula (Z102), or structural formula (Z103) is bonded is substituted with a functional group containing a hydroxyl group, an amino group, or a glycidyl group, in the structure shown in structural formula (1), structural formula (2), or structural formula (3) described above. The ionic compound is a precursor of at least one cationic structure selected from the group consisting of structures represented by structural formulas (1) to (3), and can be introduced into polyurethane, for example, by reacting with an isocyanate group or a hydroxyl group to form the cationic structure.

[0055] In the case of a cationic skeleton containing a cationic nitrogen-containing heteroaromatic ring, conjugation causes the positive charge that was on the nitrogen atom to be distributed to the other atoms on the aromatic ring, centered around the nitrogen atom. As a result, the range of adsorption with CNTs is broadened.

[0056] The structure shown in structural formula (1) can be formed by a nitrogen-containing heteroaromatic five-membered ring cation having at least one functional group containing a hydroxyl group, an amino group, or a glycidyl group, and further containing two nitrogen atoms.

[0057] If the structure shown in structural formula (1) is a nitrogen-containing heteroaromatic five-membered ring cation having at least one functional group containing a hydroxyl group, then the following can be said: that is, an ion containing the cation. By reacting the compound with an isocyanate group, a structure having at least one of the structures shown in structural formula (Z101) can be obtained.

[0058] If the structure shown in structural formula (1) is a nitrogen-containing heteroaromatic five-membered ring cation having at least one functional group containing an amino group, then the following can be said: That is, by reacting an ionic compound containing the cation with an isocyanate group, a structure having at least one of the structures shown in structural formula (Z102) can be obtained.

[0059] If the structure shown in structural formula (1) is a nitrogen-containing heteroaromatic five-membered ring cation having at least one functional group containing a glycidyl group, then the following can be said: That is, by reacting an ionic compound containing the cation with a hydroxyl group, a structure having at least one of the structures shown in structural formula (Z103) can be obtained.

[0060] In structural formula (1), the nitrogen-containing heteroaromatic five-membered ring is preferably imidazolium. A suitable structure is the one having an imidazoline ring, as shown in structural formula (4) below. In structural formula (4), Z1, Z2, Z3, and d1 are the same as in structural formula (1).

[0061] [ka]

[0062] In structural formula (4), d1 represents an integer of 0 or 1, and Z1 to Z3 each independently represent the structure shown in structural formula (Z101), the structure shown in structural formula (Z102), the structure shown in structural formula (Z103), a hydrogen atom, or a hydrocarbon group having 1 to 4 carbon atoms (preferably 1 to 2, more preferably 1). However, at least one of Z1 to Z3 is the structure shown in structural formula (Z101), the structure shown in structural formula (Z102), or the structure shown in structural formula (Z103).

[0063] Examples of ionic compounds that can form the structure shown in structural formula (1) include cations having an imidazoline ring structure and a hydroxyl group, as listed below. 1-methyl-3-hydroxymethylimidazolium cation, 1-methyl-3-(2-hydroxyethyl)imidazolium cation, 1-methyl-3-(3-hydroxypropyl)imidazolium cation, 1-methyl-3-(4-hydroxybutyl)imidazolium cation, 1-methyl-3-(6-hydroxyhexyl)imidazolium cation, 1-methyl-3-(8-hydroxyoctyl)imidazolium cation, 1-ethyl-3-(2-hydroxyethyl)imidazolium cation, 1-n-butyl-3-(2-hydroxyethyl)imidazolium cation, 1,3-dimethyl-2-(2-hydroxyethyl)imidazolium cation, 1,3-dimethyl-2-(4-hydroxybutyl)imidazolium cation, 1,3-dimethyl-4-(2-hydroxyethyl)imidazolium cation; 1,3-Bishydroxymethylimidazolium cation, 1,3-Bis(2-hydroxyethyl)imidazolium cation, 2-Methyl-1,3-Bishydroxymethylimidazolium cation, 2-Methyl-1,3-Bis(2-hydroxyethyl)imidazolium Cation, 4-methyl-1,3-bis(2-hydroxyethyl)imidazolium cation, 2-ethyl-1,3-bis(2-hydroxyethyl)imidazolium cation, 4-ethyl-1,3-bis(2-hydroxyethyl)imidazolium cation, 2-n-butyl-1,3-bis(2-hydroxyethyl)imidazolium cation, 4-n-butyl-1,3-bis(2-hydroxyethyl)imidazolium cation, 1,3-bis(3- 1,3-Droxypropyl)imidazolium cation, 1,3-Bis(4-hydroxybutyl)imidazolium cation, 1,3-Bis(6-hydroxyhexyl)imidazolium cation, 1,3-Bis(8-hydroxyoctyl)imidazolium cation, 1-Methyl-2,3-Bis(2-hydroxyethyl)imidazolium cation, 1-Methyl-3,4-Bis(2-hydroxyethyl)imidazolium cation, 1-Methyl-3,5-Bis(2 -Hydroxyethyl)imidazolium cation; 1,2,3-Tris(2-hydroxyethyl)imidazolium cation, 1,2,3-Tris(3-hydroxypropyl)imidazolium cation, 1,2,3-Tris(4-hydroxybutyl)imidazolium cation, 1,2,3-Tris(6-hydroxyhexyl)imidazolium cation, 1,2,3-Tris(8-Hydro Roxyoctyl)imidazolium cation, 1,3,4-tris(2-hydroxyethyl)imidazolium cation, 1,3,4-tris(3-hydroxypropyl)imidazolium cation, 1,3,4-tris(4-hydroxybutyl)imidazolium cation, 1,3,4-tris(6-hydroxyhexyl)imidazolium cation, 1,3,4-tris(8-hydroxyoctyl)imidazolium cation; and derivatives thereof.

[0064] The cation having an imidazoline ring structure and at least one functional group containing an amino group or a glycidyl group is not particularly limited. For example, a cation having the imidazoline ring structure exemplified above and having a hydroxyl group is obtained by substituting the hydroxyl group with a functional group containing an amino group or a glycidyl group.

[0065] The structure shown in structural formula (2) can be formed by a nitrogen-containing heteroaromatic six-membered ring cation having at least one functional group containing a hydroxyl group, an amino group, or a glycidyl group, and further containing two nitrogen atoms.

[0066] If the structure shown in structural formula (2) is a nitrogen-containing heteroaromatic six-membered ring cation having at least one functional group derived from a hydroxyl group, then the following can be said: That is, by reacting an ionic compound containing the cation with an isocyanate group, a structure having at least one of the structures shown in structural formula (Z101) can be obtained.

[0067] If the structure shown in structural formula (2) is a nitrogen-containing heteroaromatic six-membered ring cation having at least one functional group containing an amino group, then the following can be said: That is, by reacting an ionic compound containing the cation with an isocyanate group, a structure having at least one of the structures shown in structural formula (Z102) can be obtained.

[0068] If the structure shown in structural formula (2) is a nitrogen-containing heteroaromatic six-membered ring cation having at least one functional group containing a glycidyl group, then the following can be said: That is, by reacting an ionic compound containing the cation with a hydroxyl group, a structure having at least one of the structures shown in structural formula (Z103) can be obtained.

[0069] Examples of nitrogen-containing heteroaromatic six-membered rings in structural formula (2) include pyrimidine rings and pyrazine rings. Examples of ionic compounds corresponding to the structure shown in structural formula (2) are listed below, which have a pyrimidine ring structure and a hydroxyl group.

[0070] 1,4-Bis(2-hydroxyethyl)pyrimidinium cation, 1,5-Bis(3- Hydroxypropyl)pyrimidinium cation, 1-(4-hydroxybutyl)-4-(2-hydroxyethyl)pyrimidinium cation, 1,4-bis(2-hydroxyethyl)-2-methylpyrimidinium cation; and derivatives thereof.

[0071] The cation having a pyrimidine ring structure and at least one functional group containing an amino group or a glycidyl group is not particularly limited. For example, a cation having the pyrimidine ring structure exemplified above and having a hydroxyl group is obtained by substituting the hydroxyl group with a functional group containing an amino group or a glycidyl group.

[0072] The structure shown in structural formula (3) can be formed by a nitrogen-containing heteroaromatic ring cation having at least one functional group containing a hydroxyl group, an amino group, or a glycidyl group, and further containing one nitrogen atom.

[0073] If the structure shown by structural formula (3) is a nitrogen-containing heteroaromatic ring cation having at least one functional group containing a hydroxyl group, then the following can be said: That is, by reacting an ionic compound containing the cation with an isocyanate group, a structure having at least one of the structures shown by structural formula (Z101) can be obtained.

[0074] If the structure shown by structural formula (3) is a nitrogen-containing heteroaromatic ring cation having at least one functional group containing an amino group, then the following can be said: That is, by reacting an ionic compound containing the cation with an isocyanate group, a structure having at least one of the structures shown by structural formula (Z102) can be obtained.

[0075] If the structure shown in structural formula (3) is a nitrogen-containing heteroaromatic ring cation having at least one functional group containing a glycidyl group, then the following can be said: That is, by reacting an ionic compound containing the cation with a hydroxyl group, a structure having at least one of the structures shown in structural formula (Z103) can be obtained.

[0076] Examples of nitrogen-containing heteroaromatic rings in structural formula (3) include pyrrole rings, pyridine rings, and azepine rings. Among these, pyridine rings are preferred, and the structure shown in structural formula (3) is preferably the structure shown in structural formula (5) below. In structural formula (5), Z6, Z7, and d3 are the same as in structural formula (3).

[0077] [ka]

[0078] In structural formula (3), d3 represents an integer of 0 or 1. Z6 and Z7 each independently represent the structure shown in structural formula (Z101), the structure shown in structural formula (Z102), the structure shown in structural formula (Z103), a hydrogen atom, or a hydrocarbon group having 1 to 4 carbon atoms (preferably 1 to 2, more preferably 1). However, at least one of Z6 and Z7 is the structure shown in structural formula (Z101), the structure shown in structural formula (Z102), or the structure shown in structural formula (Z103). It is made.

[0079] Examples of ionic compounds corresponding to the structure shown in structural formula (3) include cations having a pyridine ring structure and a hydroxyl group, as listed below. 1-Hydroxymethylpyridinium cation, 1-(2-hydroxyethyl)pyridinium cation, 1-(3-hydroxypropyl)pyridinium cation, 1-(4-hydroxybutyl)pyridinium cation, 1-(6-hydroxyhexyl)pyridinium cation, 1-(8-hydroxyoctyl)pyridinium cation, 2-methyl-1-(2-hydroxyethyl)pyridinium cation, 3-methyl-1-(2-hydroxyethyl)pyridinium cation, 4-methyl-1-(2-hydroxyethyl)pyridinium cation, 3-ethyl-1-(2-hydroxyethyl)pyridinium cation, 3-n-butyl-1-(2-hydroxyethyl)pyridinium cation Ethyl)pyridinium cation, 1-methyl-2-hydroxymethylpyridinium cation, 1-methyl-3-hydroxymethylpyridinium cation, 1-methyl-4-hydroxymethylpyridinium cation, 1-methyl-2-(2-hydroxyethyl)pyridinium cation, 1-methyl-3-(2-hydroxyethyl)pyridinium cation, 1-methyl-4-(2-hydroxyethyl)pyridinium cation, 1-ethyl-3-(2-hydroxyethyl)pyridinium cation, 1-n-butyl-3-(2-hydroxyethyl)pyridinium cation, 2-methyl-4-n-butyl-1-(2-hydroxyethyl)pyridinium cation; 1,2-Bishydroxymethylpyridinium cation, 1,3-Bishydroxymethylpyridinium cation, 1,4-Bishydroxymethylpyridinium cation, 1,2-Bis(2-hydroxyethyl)pyridinium cation, 1,3-Bis(2-hydroxyethyl)pyridinium cation, 1,4-Bis(2-hydroxyethyl)pyridinium cation, 1,2-Bis(3-hydroxypropyl)pyridinium cation, 1,3-Bis(3-hydroxypropyl)pyridinium cation, 1,4-Bis(3-hydroxypropyl)pyridinium cation, 1,2-Bis(4-hydroxybutyl)pyridinium cation, 1,3-Bis(4-hydroxybutyl)pyridinium cation, 1,4-Bis(4-hydroxybutyl)pyridinium Lysinium cation, 1,2-bis(6-hydroxyhexyl)pyridinium cation, 1,3-bis(6-hydroxyhexyl)pyridinium cation, 1,4-bis(6-hydroxyhexyl)pyridinium cation, 1,2-bis(8-hydroxyoctyl)pyridinium cation, 1,3-bis(8-hydroxyoctyl)pyridinium cation, 1,4-bis(8-hydroxyoctyl)pyridinium cation, 2-methyl-1,3-bis(2-hydroxyethyl)pyridinium cation, 2-ethyl-1,3-bis(2-hydroxyethyl)pyridinium cation, 5-methyl-1,3-bis(2-hydroxyethyl)pyridinium cation, 5-ethyl-1,3-bis(2-hydroxyethyl)pyridinium cation; 1,2,4-Trishydroxymethylpyridinium cation, 1,2,4-Tris(2-hydroxyethyl)pyridinium cation, 1,2,4-Tris(3-hydroxypropyl)pyridinium cation, 1,2,4-Tris(4-hydroxybutyl)pyridinium cation, 1,2,4-Tris(6-hydroxyhexyl)pyridinium cation, 1,2,4-Tris(8-hydroxyoctyl)pyridinium cation, 1,3,5-Trishydroxymethylpyridinium cation, 1,3,5-Tris(2-hydroxyethyl)pyridinium cation, 1,3,5-Tris(3-hydroxypropyl)pyridinium cation, 1,3,5-Tris(4-hydroxybutyl)pyridinium cation, 1,3,5-Tris(6-hydroxyhexyl)pyridinium cation, 1,3,5-Tris(8-hydroxyoctyl)pyridinium cation; and derivatives thereof.

[0080] The cation having a pyridine ring structure and having at least one functional group containing an amino group or a glycidyl group is not particularly limited. For example, the structure obtained by substituting the hydroxyl group of a cation having a pyridine ring structure as exemplified above with a functional group containing an amino group or a glycidyl group. Cationes are cited as examples.

[0081] The structure shown in structural formula (Z101) is a group formed by the reaction of a hydroxyl group on a cation with an isocyanate group. The structure shown in structural formula (Z102) is a group formed by the reaction of an amino group on a cation with an isocyanate group. The isocyanate group that reacts with the hydroxyl group and the amino group is preferably an isocyanate group present in the polyurethane raw material mixture, such as polyisocyanate. The structure shown in structural formula (Z103) is a group formed by the reaction of a glycidyl group on a cation with a hydroxyl group. The hydroxyl group that reacts with the glycidyl group is preferably a hydroxyl group present in the polyurethane raw material mixture, such as polyol.

[0082] Of the structures represented by structural formulas (1) to (3), the polyurethane preferably has the structure represented by structural formula (1). Furthermore, of the structures represented by structural formula (1), the polyurethane preferably has the structure represented by structural formula (4). When the polyurethane has the structure represented by structural formula (1), the π electron density near the aromatic ring that causes adsorption with CNTs becomes higher due to the chemical structure of the cation.

[0083] <Anion> Polyurethane preferably contains anions. In the conductive elastic layer of the conductive elastic roller, the anions contained in an electrically opposite charge to the cation having a nitrogen-containing heteroaromatic ring structure as its backbone are not particularly limited. The anion preferably contains at least one anion selected from the group consisting of fluoroalkylsulfonylimide anions, fluorosulfonylimide anions, fluoroalkyl sulfonate anions, fluorosulfonate anions, fluoroalkyl carboxylic acid anions, fluoroalkylmethide anions, fluoroborate anions, fluorophosphate anions, dicyanamide anions, and thiocyanate anions. The reason for this is that, due to their chemical structure, the above-mentioned anions are chemically much more stable than halogen anions, sulfate anions, and nitrate anions. Chlorine anions and perchlorate anions can also be used as anions.

[0084] Specifically, fluoroalkylsulfonylimide anions include at least one selected from the group consisting of fluoroalkylsulfonylimide anions having a fluoroalkyl group with 1 to 6 carbon atoms, such as bis(trifluoromethanesulfonyl)imide anion, bis(pentafluoroethanesulfonyl)imide anion, bis(heptafluoropropanesulfonyl)imide anion, bis(nonafluorobutanesulfonyl)imide anion, bis(dodecafluoropentanesulfonyl)imide anion, and bis(perfluorohexanesulfonyl)imide anion, and cyclic fluoroalkylsulfonylimide anions such as N,N-hexafluoropropane-1,3-disulfonylimide.

[0085] Fluorosulfonylimide anions include, specifically, bis(fluorosulfonyl)imide anions.

[0086] Specifically, the fluoroalkyl sulfonate anion is at least one selected from the group consisting of trifluoromethanesulfonate anion, fluoromethanesulfonate anion, perfluoroethanesulfonate anion, perfluoropropanesulfonate anion, perfluorobutanesulfonate anion, perfluoropentanesulfonate anion, perfluorohexanesulfonate anion, and perfluorooctanesulfonate anion.

[0087] Specifically, the fluoroalkyl carboxylic acid anion is at least one selected from the group consisting of trifluoroacetate anion, perfluoropropionate anion, perfluorobutyrate anion, perfluorovalerate anion, and perfluorocaproate anion.

[0088] Fluoroalkylmethide anions specifically include tris(trifluoromethanesulfonyl)methide anion, tris(perfluoroethanesulfonyl)methide anion, tris(perfluoropropanesulfonyl)methide anion, and tris(perfluoro At least one selected from the group consisting of tansulfonyl)methionine, tris(perfluoropentanesulfonyl)methionine, tris(perfluorohexanesulfonyl)methionine, and tris(perfluorooctanesulfonyl)methionine.

[0089] Fluoroborate anions include, specifically, tetrafluoroborate anions. Fluorophosphate anions include, specifically, hexafluorophosphate anions.

[0090] The anions are bis(fluorosulfonyl)imide anion, bis(trifluoromethanesulfonyl)imide anion, (CF3SO2)2N respectively. - , (FSO2)2N - At least one anion selected from the group consisting of anions represented by the chemical formula ( ) is preferred, and a bis(fluorosulfonyl)imide anion is more preferred.

[0091] <Other constituent materials> The conductive elastic layer of the conductive elastic roller may contain catalysts, foaming agents, foam stabilizers, and other auxiliary agents as needed. There are no particular restrictions on the catalyst, and various known catalysts can be appropriately selected and used. For example, amine catalysts (triethylenediamine, bis(dimethylaminoethyl) ether, N,N,N',N'-tetramethylhexanediamine, 1,8-diazabicyclo(5,4,0)undecene-7, 1,5-diazabicyclo(4,3,0)nonene-5, 1,2-dimethylimidazole, N-ethylmorpholine, N-methylmorpholine, etc.), organometallic catalysts (tin octylate, tin oleate, dibutyltin dilaurate, dibutyltin diacetate, tetra-i-propoxytitanium, tetra-n-butoxytitanium, tetrakis(2-ethylhexyloxy)titanium, etc.), and acid salt catalysts (carboxylates, formates, octylates, borates, etc.) with reduced initial activity of the amine and organometallic catalysts can be used. One catalyst may be used, or two or more may be used in combination.

[0092] There are no particular restrictions on the blowing agent; various known blowing agents can be appropriately selected and used. In particular, water is suitable as a blowing agent because it reacts with polyisocyanate to generate carbon dioxide. Water may also be used in combination with other blowing agents.

[0093] There are no particular restrictions on the foam stabilizer; any known foam stabilizer can be appropriately selected and used. Other auxiliary agents may be used as needed, to the extent that they do not impair the effects of the present disclosure, including crosslinking agents, flame retardants, colorants, ultraviolet absorbers, antioxidants, and conductive fillers. Conductive fillers may include carbon black, aluminum, copper, and other conductive metals. Furthermore, other ionic compounds may be used in combination, to the extent that they do not impair the effects of the present disclosure. From the viewpoint of stability, the total content of the ionic compounds is preferably 0.1 parts by mass or more and 30 parts by mass or less per 100 parts by mass of the binder resin forming the conductive elastic layer.

[0094] <Method for forming a conductive elastic layer> There are no particular restrictions on the method for forming the conductive elastic layer. Here, we describe a method for forming a conductive elastic roller in which the conductive elastic layer has a foamed structure, but the method is not limited to this. When the conductive elastic layer has a foamed structure, there are no particular restrictions on the foaming method. Any method can be used, such as using a foaming agent or mixing in bubbles by mechanical stirring. The foaming ratio can be determined as appropriate and is not particularly restricted.

[0095] For example, by mixing materials 1 to 6 below and reacting them while foaming, a conductive elastic layer for a conductive elastic roller can be obtained. 1. As a material for forming the binder resin, 1-1. At least one polyol selected from the group consisting of polyether polyols, polyester polyols, etc., and 1-2. Polyisocyanates 2. Compounds having a nitrogen-containing heteroaromatic ring structure and containing at least one functional group selected from the group consisting of hydroxyl groups, amino groups, and glycidyl groups. 3. CNT 4. Catalyst 5. Foam stabilizer 6. Foaming agent

[0096] It is preferable to prepare in advance a CNT-containing composite material containing part or all of the above 2 and 3, or part or all of 2, 3 and part of 1-1. More preferably, the composite material is prepared by a method that includes a step of applying shear force to the CNTs in the presence of a compound containing a nitrogen-containing heteroaromatic ring structure to defibrate them. This is because inducing the adsorption of the CNTs with the compound containing the nitrogen-containing composite ring structure in advance can suppress the re-aggregation of the defibrated CNTs.

[0097] The method of applying shear force is not particularly limited and can include kneading methods using equipment such as kneaders, roller kneaders, and twin-screw kneaders, granulation methods that involve collision with CNTs, and even simple methods such as kneading with a pestle on a mortar. Of these, the method of applying shear force using a roller kneader is preferred because it can apply shear force for defibrillation while preventing the CNTs from being cut, and defibrillation can be easily controlled from the operating conditions of the equipment.

[0098] In the composite material, the amount of CNTs is preferably 3 to 300 parts by mass, and more preferably 10 to 200 parts by mass, per 100 parts by mass of the compound containing the nitrogen-containing heteroaromatic ring structure. Within this range, sufficient shear force for defibrillation can be applied, while re-aggregation of CNTs is less likely to occur. In addition, materials other than 2 and 3 may be included when producing the CNT-containing composite material.

[0099] In the material for forming the conductive elastic layer, the total amount of CNTs is preferably within the following range from the viewpoint of conductivity and suppression of resistance fluctuations due to current flow. That is, the total amount of CNTs in the conductive elastic layer is, for example, 0.005 to 10.00 parts by mass per 100 parts by mass of binder resin. Preferably, it is 0.01 to 1.00 parts by mass, more preferably 0.01 to 0.50 parts by mass, and even more preferably 0.02 to 0.10 parts by mass.

[0100] Furthermore, the total content of the nitrogen-containing heteroaromatic ring structure is preferably within the following range from the viewpoint of conductivity and suppression of resistance fluctuations due to current flow. The content of the nitrogen-containing heteroaromatic ring structure (preferably the sum of the structure represented by structural formula (1), the structure represented by structural formula (2), and the structure represented by structural formula (3)) is, for example, 0.005 to 10.00 mass% based on the mass of the conductive elastic layer. Preferably, it is 0.01 to 5.00% by mass, more preferably 0.01 to 1.00% by mass, and even more preferably 0.05 to 0.50% by mass.

[0101] When reacting while foaming, there are no particular restrictions on the temperature or time when mixing materials 1 to 6. The mixing temperature is usually in the range of 10°C to 90°C, preferably 20°C to 80°C. The mixing time depends on the structure of the mixing unit used, the rotation conditions, etc., but is usually 1 second to 20 minutes, preferably 3 seconds to 15 minutes.

[0102] There are no particular restrictions on the method of joining the substrate and the conductive elastic layer having a foamed structure. Methods include pre-arranging the substrate inside a mold and then casting and curing the raw material mixture as described above, or pre-molding the raw material mixture into a predetermined shape for the foamed elastic layer and then bonding it to the substrate. In either method, an adhesive layer can be provided between the substrate and the conductive elastic layer having a foamed structure as needed. Known materials such as adhesives or hot-melt sheets can be used for this adhesive layer.

[0103] In the case of casting curing, a mold release agent may be applied to the inner wall of the mold beforehand. Known mold release agents can be used. Examples include water-based mold release agents containing wax components and silicone oil, and mold release agents in which fluororesin is dissolved in a fluorine-based solvent. An example of a fluororesin-containing mold release agent is a fluororesin-containing mold release agent (product name: Fluorosurf, FG-5093F130-0.5, manufactured by Fluorotechnology Co., Ltd.).

[0104] There are no particular restrictions on the method for forming the shape of the conductive elastic layer, i.e., the foamed elastic layer, as a conductive elastic roller having a foamed structure. For example, in addition to the method of casting into a mold of a predetermined shape as described above, the following methods can be used: cutting out predetermined dimensions from a block of polyurethane foam by machining, making it to predetermined dimensions by polishing, or a combination of these methods as appropriate.

[0105] Furthermore, the state after these reactions can be confirmed by analyzing it using known methods such as pyrolysis GC / MS, FT-IR, NMR, and GPC.

[0106] <Electrophotographic image forming apparatus> The electrophotographic image forming apparatus according to this disclosure comprises a conductive elastic roller according to this disclosure. That is, the conductive elastic roller can be used as at least one of a developing roller, a charging roller, a transfer roller, and a toner supply roller in an electrophotographic image forming apparatus, and in particular, the conductive elastic roller can be suitably used as a toner supply roller. The conductive elastic roller can be applied to any type of developing apparatus, whether it is a non-contact type or contact type developing apparatus using magnetic one-component toner or non-magnetic one-component toner, or a developing apparatus using two-component toner.

[0107] Figure 2 is a schematic cross-sectional view showing an example of an electrophotographic image forming apparatus in which a conductive elastic roller is mounted as a toner supply roller in a contact-type developing apparatus using a single-component toner. The developing apparatus 22 includes a toner container 20 containing toner 15 as a single-component toner, a developing roller 16, a toner supply roller 19 that supplies toner to the developing roller 16, and a developing blade 21 that regulates the thickness of the toner layer on the developing roller 16.

[0108] The developing roller 16 is located in a longitudinally extending opening within the toner container 20 and is in contact with the electrophotographic photoreceptor 18. The electrophotographic photoreceptor 18, cleaning blade 26, waste toner container 25, and charging roller 24 may be located in the main body of the electrophotographic image forming apparatus. The developing unit 22 is available for each color toner: black (Bk), cyan (C), magenta (M), and yellow (Y), enabling color printing.

[0109] The following describes the printing operation of the electrophotographic image forming apparatus. The electrophotographic photoreceptor 18 rotates in the direction of the arrow and is uniformly charged by the charging roller 24 for charging the electrophotographic photoreceptor 18. Next, an electrostatic latent image is formed on the surface of the electrophotographic photoreceptor 18 by the laser light 23, which is the exposure means. This electrostatic latent image is made visible as a toner image (development) by the developing apparatus 22, which applies toner 15 from the developing roller 16 that is in contact with the electrophotographic photoreceptor 18. Development is so-called inversion development, in which a toner image is formed in the exposed area.

[0110] The toner image formed on the electrophotographic photoreceptor 18 is transferred to the recording medium, paper 34, by a transfer roller 29, which is a transfer member. The paper 34 is fed into the device via a paper feed roller 35 and a suction roller 36, and is transported between the electrophotographic photoreceptor 18 and the transfer roller 29 by an endless belt-shaped transfer transport belt 32. The transfer transport belt 32 is operated by a driven roller 33, a drive roller 28, and a tension roller 31. Voltage is applied from a bias power supply 30 to the developing roller 16, developing blade 21, toner supply roller 19, and suction roller 36.

[0111] The paper 34 onto which the toner image has been transferred is fixed by the fuser unit 27 and then ejected from the unit, ending the printing operation. Meanwhile, any remaining toner that was not transferred and remains on the electrophotographic photoreceptor 18 is scraped off by the cleaning blade 26, a cleaning component for cleaning the surface of the photoreceptor, and stored in the waste toner container 25. The cleaned electrophotographic photoreceptor 18 then repeats the above printing operation.

[0112] <Processing Cartridge> This disclosure relates to a process cartridge that is detachably configured to be attached to the main body of an electrophotographic image forming apparatus. The process cartridge comprises the conductive elastic roller described above. The conductive elastic roller having a conductive elastic layer is used as at least one of a charging roller, a developing roller, a transfer roller, and a toner supply roller. In particular, the conductive elastic roller can be suitably used as a toner supply roller 19 in the process cartridge.

[0113] Figure 3 is a schematic cross-sectional view showing an example of a process cartridge. The process cartridge 17 is configured to be detachably attached to the main body of the electrophotographic image forming apparatus. The process cartridge 17 integrates a developing device 22, an electrophotographic photoreceptor 18, a cleaning blade 26 which is a cleaning means, a waste toner container 25, and a charging roller 24 which is a charging means.

[0114] Here, the developing device 22 includes a developing roller 16 and a developing blade 21, which are developing means. The developing device 22 further includes a toner container 20, which is filled with toner 15. The toner 15 in the toner container 20 is supplied to the surface of the developing roller 16 by a toner supply roller 19, and the developing blade 21 forms a layer of toner 15 of a predetermined thickness on the surface of the developing roller 16. Each component of the process cartridge 17 is the same as that described in Figure 2.

[0115] <Regarding the toner supply method using the toner supply roller> There are two methods for supplying toner to the developing roller 16 by the toner supply roller 19: a mechanical supply method and an electrical supply method.

[0116] The mechanical supply method involves holding toner on the surface layer of the toner supply roller 19 and supplying the toner through contact with the developing roller 16. In this case, if the surface layer of the toner supply roller 19 is a layer with voids, such as a foamed layer, the amount of toner held increases, and toner is supplied more efficiently. This can be done. Furthermore, if the surface layer of the toner supply roller 19 is a foamed elastic layer, the foamed elastic layer contracts when it comes into contact with the developing roller 16, pushing out the retained toner and promoting the discharge of toner from the toner supply roller 19.

[0117] The electrical supply method utilizes the biasing force of the charged toner, which is generated by the bias potential difference between the bias applied to the toner supply roller 19 and the bias applied to the developer roller 16. Specifically, when the polarity of the bias potential difference is the same as the normal charging polarity of the toner, a biasing force acts on the toner at the contact point from the toner supply roller 19 towards the developer roller 16. This is how the toner is supplied. [Examples]

[0118] The present disclosure will be described in further detail below using examples and comparative examples, but the embodiments of the present disclosure are not limited thereto.

[0119] We synthesized an ionic compound containing a nitrogen-containing heteroaromatic ring structure, which is a raw material for the polyurethane contained in the conductive elastic layer of a conductive elastic roller.

[0120] <Synthesis of compositions containing ionic compounds> (Composition C-1) A round-bottom flask fitted with a Liebig condenser is filled with a stirring bar and tetrahydrofuran (THF) 60 ml of (manufactured by Kanto Chemical Co., Ltd.) was added, and 24.0 g (0.60 mol) of sodium hydride (60% by mass, dispersed in liquid paraffin, manufactured by Tokyo Chemical Industry Co., Ltd.) was dispersed in it. The round-bottom flask was cooled in an ice bath. A solution of 10.2 g (0.15 mol) of imidazole (manufactured by Tokyo Chemical Industry Co., Ltd.) dissolved in 60 ml of THF was slowly added dropwise, and the ice bath was removed and the mixture was stirred at room temperature for 2 hours. 47.6 g (0.38 mol) of 2-bromoethanol (manufactured by Tokyo Chemical Industry Co., Ltd.) was added at room temperature, and the mixture was heated under reflux at 70°C for 7 hours. The reaction mixture was filtered, insoluble matter was washed away with THF, and the solvent of the resulting filtrate was removed by vacuum distillation. The resulting product was dissolved in 590.5 g of water, and 179.3 g of ion exchange resin DOWEX 550A OH (manufactured by DuPont) was added, and the mixture was stirred at room temperature for 1 hour. The ion exchange resin was filtered, and to the resulting aqueous solution, an aqueous solution prepared by dissolving 27.2 g of Imidodisulfurylfluoride Lithium (manufactured by Aaron Chemicals) in 379.6 g of water was added dropwise over 2 hours. During the dropwise addition, the pH was simultaneously monitored, and the endpoint was reached at pH 6.3. The solvent of the resulting aqueous solution was removed by vacuum distillation to obtain composition C-1 according to Example 1. Ionic compound 1 contained in composition C-1 is a compound represented by the following structural formula (C1).

[0121] [ka]

[0122] (Composition C-2, 3, 6) The anionic raw materials and their proportions, C-2 is 13.4g of tetrafluoroboric acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.). C-3 is Thiocyanic acid (manufactured by A2B Chem) 58.0g. Compositions C-2, 3, and 6 were obtained in the same manner as the synthesis of composition C-1, except that C-6 was replaced with 42.2 g of bis(trifluoromethanesulfonyl)imide (manufactured by Tokyo Chemical Industry Co., Ltd.). The ionic compounds 2, 3, and 6 contained in compositions C-2, 3, and 6 have the same cation structure as ionic compound 1, and their anions are tetrafluoroborate anion, thiocyanate anion, and bis(trifluoromethanesulfonyl)imide anion, respectively.

[0123] (Composition C-4) A round-bottom flask fitted with a Liebig condenser is filled with a stirring bar and tetrahydrofuran (THF) Add 60 ml of (manufactured by Kanto Chemical Co., Ltd.), disperse 24.0 g (0.60 mol) of sodium hydride (60% by mass, dispersed in liquid paraffin, manufactured by Tokyo Chemical Industry Co., Ltd.), and cool the round-bottom flask in an ice bath. Slowly add a solution of 10.2 g of 2-methylimidazole-1-ethanol (manufactured by Sigma-Aldrich) dissolved in 60 ml of THF, then remove the ice bath and stir at room temperature for 2 hours. 47.6 g (0.38 mol) of 2-bromoethanol (manufactured by Tokyo Chemical Industry Co., Ltd.) was added at room temperature, and the mixture was heated under reflux at 70°C for 7 hours. The reaction mixture was filtered, insoluble matter was washed away with THF, and the solvent of the resulting filtrate was removed by vacuum distillation. The resulting product was dissolved in 590.5 g of water, and 179.3 g of ion exchange resin DOWEX 550A OH (manufactured by DuPont) was added, and the mixture was stirred at room temperature for 1 hour. The ion exchange resin was filtered, and to the resulting aqueous solution, an aqueous solution prepared by dissolving 27.2 g of Imidodisulfurylfluoride Lithium (manufactured by Aaron Chemicals) in 379.6 g of water was added dropwise over 2 hours. During the dropwise addition, the pH was simultaneously monitored, and the endpoint was reached at pH 6.3. The solvent of the resulting aqueous solution was removed by vacuum distillation to obtain composition C-4 according to Example 1. Ionic compound 4 contained in composition C-4 is a compound represented by the following structural formula (C4).

[0124] [ka]

[0125] (Composition C-5) Composition C-5 was obtained in the same manner as the synthesis of composition C-4, except that the anionic raw material and its amount were 58.0 g of thiocyanic acid (manufactured by A2B Chem). The cation structure of ionic compound 5 contained in composition C-5 is the same as that of ionic compound 4, and the anion is a thiocyanate anion.

[0126] (Composition C-7) Under a nitrogen atmosphere, 15.0 g of imidazole-2-ethanol (Sigma-Aldrich) and 9.2 g of sodium hydride (60%, dispersed in liquid paraffin) (Tokyo Chemical Industries) were dissolved in 60.0 g of tetrahydrofuran. Then, 42.1 g of 2-bromoethanol (Tokyo Chemical Industries), dissolved in 80.0 g of tetrahydrofuran, was added dropwise over 30 minutes at room temperature, and the mixture was heated under reflux at 85°C for 12 hours. Next, 100 ml of water was added to the reaction solution, and the solvent was removed under reduced pressure. 200 ml of ethanol was added to the residue, stirred at room temperature, and insoluble matter was removed by Celite filtration. Then, under reduced pressure again... The solvent was removed by distillation.

[0127] The obtained product was dissolved in 200 ml of pure water, and 48.3 g of lithium N,N-bis(trifluoromethanesulfonyl)imide (trade name: EF-N115, manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.) was added as the anion starting material. The mixture was stirred at room temperature for 1 hour. 200 ml of ethyl acetate was added to the reaction solution, and the organic layer was washed three times with 120 g of deionized water. Next, ethyl acetate was removed under reduced pressure to obtain composition C-7. Ionic compound 7 contained in composition C-7 is the compound represented by the following structural formula (C7).

[0128] [ka]

[0129] (Composition C-8) 15.0 g of 5-methylpyrazine-2-methanol (Sigma-Aldrich) and 9.2 g of sodium hydride (60%, dispersed in liquid paraffin) (Tokyo Chemical Industries) were dissolved in 80.0 g of tetrahydrofuran. Then, 18.9 g of methyl iodide (Tokyo Chemical Industries), dissolved in 80.0 g of tetrahydrofuran, was added dropwise over 30 minutes at room temperature, and the mixture was heated under reflux at 85°C for 12 hours. Next, 100 ml of water was added to the reaction solution, and the solvent was removed under reduced pressure. 200 ml of ethanol was added to the residue, and the mixture was stirred at room temperature. After removing insoluble matter by Celite filtration, the solvent was again removed under reduced pressure.

[0130] The obtained product was dissolved in 100 ml of pure water, and 38.1 g of lithium N,N-bis(trifluoromethanesulfonyl)imide (trade name: EF-N115, manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.) was added as the anion starting material. The mixture was stirred at room temperature for 1 hour. 100 ml of ethyl acetate was added to the reaction solution, and the organic layer was washed three times with 80 g of deionized water. Next, ethyl acetate was removed under reduced pressure to obtain composition C-8. Ionic compound 8 contained in composition C-8 is the compound represented by the following structural formula (C8).

[0131] [ka]

[0132] (Composition C-9) 15.0 g of 4-pyridinebutanol (Sigma-Aldrich) was dissolved in 45.0 g of acetonitrile, and 16.7 g of 4-bromo-1-butanol (Tokyo Chemical Industries) was added dropwise over 30 minutes at room temperature. The mixture was then heated under reflux at 90°C for 12 hours.

[0133] Next, the reaction solution was cooled to room temperature, and acetonitrile was removed under reduced pressure. The resulting mixture was washed with 30.0 g of diethyl ether, and the supernatant was removed by liquid-liquid separation. The washing and liquid-liquid separation process was repeated three times to obtain the residue. Furthermore, the obtained residue was dissolved in 110.0 g of dichloromethane, and then 31.4 g of the anionic raw material, dissolved in 40.0 g of deionized water, was added dropwise over 30 minutes, followed by stirring at 30°C for 12 hours. The anionic raw material used was lithium N,N-bis(trifluoromethanesulfonyl)imide (trade name: EF-N115, manufactured by Mitsubishi Materials Electronics Chemicals Co., Ltd.). The obtained solution was separated, and the organic layer was washed three times with 80.0 g of deionized water. Subsequently, dichloromethane was removed under reduced pressure to obtain composition C-9. Ionic compound 9 contained in composition C-9 is a compound represented by the following formula (C9).

[0134] [ka]

[0135] (Composition C-10) As a cation raw material, 15.0 g of imidazole (manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in 50.0 g of dichloromethane. Then, 44.9 g of epichlorohydrin (manufactured by Tokyo Chemical Industry Co., Ltd.), dissolved in 50.0 g of dichloromethane, was added dropwise over 30 minutes at room temperature, and the mixture was heated under reflux for 6 hours. Next, the reaction solution was cooled to room temperature, 200 ml of 5% by mass aqueous sodium carbonate solution was added, and the mixture was stirred for 30 minutes. After separation, the dichloromethane layer was washed twice with 120 g of deionized water. Next, the dichloromethane was removed under reduced pressure to obtain the residue. Furthermore, the obtained residue was dissolved in 50.0 g of acetone. Subsequently, 69.6 g of the anionic raw material dissolved in 150.0 g of deionized water was added dropwise over 30 minutes, and the mixture was stirred at 30°C for 2 hours. The anionic raw material used was lithium N,N-bis(trifluoromethanesulfonyl)imide (trade name: EF-N115, manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.). The resulting solution was separated, and the organic layer was washed three times with 50.0 g of deionized water. Then, acetone was removed under reduced pressure to obtain composition C-10. The ionic compound 10 contained in composition C-10 is a compound represented by the following formula (C10).

[0136] [ka]

[0137] (Composition C-11) 15.0 g of 1-(3-aminopropyl)imidazole (Sigma-Aldrich) and 8.6 g of sodium hydride (60%, dispersed in liquid paraffin) (Tokyo Chemical Industries) were dissolved in 80.0 g of tetrahydrofuran. Then, 18.7 g of methyl iodide (Tokyo Chemical Industries), dissolved in 80.0 g of tetrahydrofuran, was added dropwise over 30 minutes at room temperature, and the mixture was heated under reflux at 85°C for 12 hours. Next, 100 ml of water was added to the reaction solution, and the solvent was removed under reduced pressure. 200 ml of ethanol was added to the residue, and the mixture was stirred at room temperature. Insoluble matter was removed by Celite filtration, and the solvent was again removed under reduced pressure. The obtained product was dissolved in 100 ml of pure water, and 37.8 g of lithium N,N-bis(trifluoromethanesulfonyl)imide (trade name: EF-N115, manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.) was added as an anion starting material. The mixture was stirred at room temperature for 1 hour. 100 ml of ethyl acetate was added to the reaction solution, and the organic layer was washed three times with 80 g of deionized water. Next, the ethyl acetate was removed under reduced pressure to obtain composition C-11. The ionic compound 11 contained in composition C-11 is a compound represented by the following formula (C11).

[0138] [ka]

[0139] (Example 1) <Manufacturing of toner supply rollers> A toner supply roller having a foamed conductive elastic layer was manufactured as a conductive elastic roller using the following process.

[0140] (Fabrication of composite material M-1) The following materials (a), (b), and (c) were prepared to constitute a composite material containing CNTs and compounds with nitrogen-containing heteroaromatic ring structures. To allow the constituent materials to come into contact and blend without applying shear force, the materials were placed in a plastic container, and the container was vacuum-degassed to obtain a mixture. To break down the fibers by applying shear force to the aforementioned mixture, an open roll apparatus (manufactured by Kansai Roll, with 6-inch front and rear rolls) was used. This apparatus rotates the two front and rear rolls while... A shear force is applied to an object by passing it through the gap between the rollers. 30g of the mixture was kneaded for 30 minutes under conditions of a 1mm gap between the rollers, a front roll rotation speed of 10rpm, and a rear roll rotation speed of 8rpm to obtain composite material M-1.

[0141] (a) CNT (ZEONANO SG101 manufactured by Zeon): 10 parts by mass (b) Compound (ionic compound) having a nitrogen-containing heteroaromatic ring structure Composition C-1: 40 parts by mass (c) Polyol (polyethylene propylene ether triol with a number-average molecular weight of 2000, trade name: Actcol EP-550N; manufactured by Mitsui Chemicals, Inc.): 50 parts by mass

[0142] (Fabrication of a conductive elastic layer having a foamed structure) The following materials (A) to (G) were used. Half of material (B) and material (A) were placed in a plastic container, and the blades of a stirring-type disperser (Homodisper 2.5 type, manufactured by Primix Corporation) were placed inside the plastic container and stirred at 3200 rpm for 20 minutes. The remaining half of material (B) was then mixed in and vacuum-degassed to prepare a precursor slurry.

[0143] A stainless steel (SUS304) mandrel with a diameter of 6 mm and a total length of 278.9 mm was coated with a primer (product name, DY35-051; manufactured by Toray Dow Corning Co., Ltd.) and baked in an oven heated to 180°C for 20 minutes to form a base. The base was then placed in a mold consisting of a cylindrical member with an inner diameter of 16.5 mm, an upper die member, and a lower die member, all of which had a release agent applied to their inner surfaces.

[0144] The aforementioned precursor slurry and materials (C) to (F) were placed in a poly container and stirred at 2000 rpm for 3 minutes using a rotation-revolution type mixer (Awatori Rentaro ARV-931TWIN, manufactured by Thinky Co., Ltd.). (G) was added to the stirred liquid and the resulting urethane rubber composition was injected into a cavity formed in the mold. Subsequently, the mold was heated to 70°C to allow the urethane rubber composition to foam and harden for 10 minutes, and the substrate with a foamed elastic layer formed on its circumferential surface was demolded from the mold. In this way, a toner supply roller T-1, which is a conductive elastic roller according to Example 1, was manufactured, having a conductive elastic layer with a foamed structure of 16.5 mm in diameter on the outer circumference of the substrate.

[0145] (A): Composite material M-1: 0.5 part by mass (B): Polyol (polyethylene propylene ether triol with a number-average molecular weight of 2000, trade name: Actcol EP-550N; manufactured by Mitsui Chemicals, Inc.): 100 parts by mass (C): Silicone foam stabilizer (product name: NIAX SILICONE L-3640, manufactured by Momentive Performance Materials): 0.3 parts by mass (D): Amine catalyst A (N-methylmorpholine, manufactured by Tokyo Chemical Industry Co., Ltd.): 1 part by mass (E): Amine catalyst B (DABCO 33-LV, manufactured by Evonik Japan): 0.5 parts by mass (F): Foaming agent (water): 1.5 parts by mass (G): Polyisocyanate mixture (containing NCO%=45, MDI=20%, trade name: Cosmonate™20; manufactured by Mitsui Chemicals, Inc.): 24.7 parts by mass Table 1 shows the materials used (a) and (b), along with their corresponding nitrogen-containing heteroaromatic ring structures and the Z1-Z3 points in each structural formula.

[0146] <Evaluation of the opening properties of the conductive elastic layer> The surface aperture properties were evaluated for use as a toner supply roller. Using a laser microscope (product name: VK-X100, manufactured by Keyence), a 5x objective lens was attached, and 20 images of a 280mm x 210mm area on the surface of the conductive elastic layer were taken. The brightness was adjusted so that the areas corresponding to voids (cells) were as dark as possible, and the areas corresponding to the framework were as bright as possible. The images obtained here were imported into image processing software (product name "Image-Pro Plus": manufactured by Planetron Co., Ltd.) and automatically binarized using the "Threshold" process, with the skeleton side being white and the void (cell) side being black. Furthermore, the total cell diameter and total number of cells in the obtained images were calculated, and the average cell diameter and average number of cells per unit area (cells / inch) were determined. 2 ) was calculated.

[0147] <Observation and length evaluation of CNTs in conductive elastic layers> This analysis was performed to determine the lengths of the carbon nanotubes (CNTs) in the toner supply roller in both the short-side and long-side directions. The length in the short-side direction was measured by obtaining a CNT surface image using a scanning electron microscope (Zeiss FE-SEM ULTRA55) and then calculating the length through image analysis. For observation, a portion of the conductive elastic layer on the toner supply roller was cut out, cooled to -100°C, and then cut into 1 μm thick sections using a cryomicrotome (product name: UC-6, Leica Microsystems).

[0148] In this process, to ensure accurate measurement regardless of the orientation of the internal CNTs, three thin sections were cut from the observation sample, each containing three mutually perpendicular planes (i.e., the XY, YZ, and ZX planes). Five locations on each thin section were observed using an in-lens SE detector in measurement mode with an exposure time of 4 minutes. An image for analysis was obtained by converting a 500 nm square area into image information with 1024 pixels or more. During this observation and image acquisition, the images were taken in a way that created a difference in brightness and contrast between the CNTs and the surrounding areas.

[0149] The images obtained here are imported into image processing software (product name "Image-Pro Plus": manufactured by Planetron Co., Ltd.), and the CNTs are automatically extracted as fibers using the "Fiber Separation" process. The angle deviation is set to 60° so that curved CNTs are also counted as fibers, and the fiber length corresponding to the length in the short side direction is calculated using the Measure Thickness process. Since the length in the short side direction of the CNT is calculated as the fiber width, the fiber width data from all five locations on the entire thin section is read into a spreadsheet, and the average of all values ​​is taken as the numerical average of the lengths in the short side direction of the CNTs. As defibrillation progresses, the length in the short side direction becomes shorter and approaches the short side length of a single CNT, which is approximately 5 nm.

[0150] The length in the direction of the longer side can be determined by three-dimensional measurement using FIB-SEM. FIB-SEM is a technique that uses a FIB (Focused Ion Beam) device to process the sample and observe the exposed cross-section with an SEM (Scanning Electron Microscope). To investigate the three-dimensional structure, it is possible to obtain numerous images by repeatedly processing and observing the sample in succession, and then perform 3D reconstruction processing on these SEM images using computer software to construct a three-dimensional image of the sample structure.

[0151] To specifically measure the length of the CNTs in the long side direction, a FIB-SEM (manufactured by FEI Co., Ltd.) was used to acquire a three-dimensional image, and the above configuration was confirmed from that image. Test specimens were cut from 30 locations in the conductive elastic layer, and three-dimensional measurements were performed using the FIB-SEM. Processing and observation were repeated at 5 μm intervals to a depth of 300 μm, and images of a 9 μm × 6 μm rectangular parallelepiped shape were measured. To ensure that the CNTs could be measured whether they were randomly oriented or oriented in a specific direction, for the measurement of the 30 samples, processing was performed in directions perpendicular to each other (3 directions): a direction parallel to the substrate, a direction from the surface toward the substrate, and a direction perpendicular to both of the above directions.

[0152] Furthermore, in order to observe the CNTs effectively, it is preferable to perform preprocessing to obtain a suitable contrast between the CNTs and the surrounding areas. The obtained images are then analyzed using 3D visualization and analysis software Avizo (registered trademark, manufactured by F.E.I. Co., Ltd.) to determine the size of one side. The length of all carbon nanotubes (CNTs) in the long-side direction within a rectangular prism-shaped region measuring 9 μm × 6 μm × 300 μm was measured, and the average value of these measurements was used as the numerical average of the long-side lengths.

[0153] <Measurement of the initial resistance value R1 of the toner supply roller> The toner supply roller was left for 12 hours in an environment with a temperature of 15°C and a relative humidity of 10%, and then the initial resistance value R1 was measured. Figures 4A and 4B show schematic diagrams of the jig used to evaluate the resistance value of the toner supply roller in this measurement. As shown in Figure 4A, non-conductive nip regulating members 41 were attached to both ends of the base body 2. In addition, a cylindrical metal 37 with a diameter of 30 mm was rotated while pressing both ends of the conductive base body 2 with a load of 4.9 N each via conductive bearings 38, causing the toner supply roller 19 to rotate in a driven manner at a speed of 32 rpm.

[0154] Next, as shown in Figure 4B, a voltage of 200V was applied by a high-voltage power supply 39, and the potential difference across a resistor with a known resistance value (a resistance value at least two orders of magnitude lower than the resistance value of the toner supply roller 19) placed between the cylindrical metal 37 and ground was measured. A voltmeter 40 (product name: 189TRUERMSMULTIMETER, manufactured by Fluke) was used to measure this potential difference. The current flowing through the cylindrical metal 37 via the toner supply roller 19 was calculated from the measured potential difference and the resistance value of the resistor. The resistance value of the toner supply roller 19 was then determined by dividing the applied voltage of 200V by the obtained current. Here, the potential difference was measured by sampling for 3 seconds starting 2 seconds after the voltage was applied, and the value calculated from the average value was taken as the initial resistance value R1 of the toner supply roller. The results are shown in Table 2.

[0155] <Performance evaluation as a toner supply roller (density difference ΔD)> To evaluate the performance of the toner supply roller, the image density change before and after long-term operation in an environment of 15°C and 10% relative humidity was evaluated using a toner supply roller whose initial resistance value had been measured. When the resistance value increases due to long-term operation, a defect occurs in the bias potential difference in the electrical supply as described above, and the desired amount of toner cannot be supplied, resulting in a decrease in image density.

[0156] The toner supply rollers obtained in each example and comparative example were loaded as toner supply roller 19 into a black toner process cartridge for a laser printer (product name: LBP-7700C, manufactured by Canon Corporation) having the configuration shown in Figure 3. The process cartridge was then assembled into the laser printer and left for one day in an environment of 15°C and 10% relative humidity to allow it to settle in, after which one solid black evaluation image was printed. Next, 8000 images with a print density of 1% in black were printed continuously as a print test. After that, one solid black evaluation image was printed again. All evaluation images and print test outputs were printed in monochrome.

[0157] The density of each solid black evaluation image was measured at a total of five points: the center and the four corners (20 mm inward from each edge of the image) using a spectrophotometer (product name: 500 Spectrophotometer, manufactured by X-Rite). The density of the solid black evaluation image was obtained by taking the arithmetic mean of the densities of the five points. When the average density of the solid black evaluation image before the print test was denoted as D1 and the average density of the solid black evaluation image after the print test as D2, the density difference ΔD, expressed as |D2-D1|, was calculated. The results are shown in Table 2.

[0158] <Measurement of the resistance value R2 of the toner supply roller after continuous operation> Following the performance evaluation (density difference ΔD), the resistance value R2 of the toner supply roller after continuous operation was measured under conditions of 15°C and 10% relative humidity. After the performance evaluation, the toner supply roller was removed from the process cartridge. Subsequently, the entire surface of the toner supply roller was air-blown.

[0159] The conditions for air blowing were as follows: Air blow gun nozzle diameter 3mm. The test setup involved high-pressure air or nitrogen gas at 0.6 MPa, a toner supply roller surface-to-nozzle distance of 20 cm, a gun movement speed of 30 cm / s (reciprocating movement speed along the longitudinal direction of the toner supply roller), a toner supply roller rotation speed of 30 rpm, and a spraying time of 30 s. Subsequently, the resistance value R2 was measured in the same manner as the initial resistance value R1. The time between the output of the solid black evaluation image after the print test and the measurement of the resistance value R2 was standardized to 30 minutes. The results are shown in Table 2. Note that the resistance change value (%) in Table 2 is calculated using the formula [(R2-R1) / R1] × 100, and is an indicator of the resistance increase rate.

[0160] (Examples 2-13) The types of materials (a) and (b) were changed as shown in Table 1. Example 12 used commercially available B-1,3-hydroxypyridine (manufactured by Tokyo Chemical Industry Co., Ltd.), which is not an ionic compound, as material (B). Example 13 used OCSiAl TUBALL 01RW03 as material (A) CNT. Otherwise, toner supply rollers T-2 to T-13 according to Examples 2 to 13 were manufactured in the same manner as in Example 1. Table 1 shows the materials (a) and (b) used and their nitrogen-containing heteroaromatic ring structures.

[0161] The toner supply rollers in Examples 1 to 13 have a conductive elastic layer containing polyurethane with a nitrogen-containing heteroaromatic ring structure. As a result, as shown in Table 2, the resistance increase was minimal even during long-term operation in a low-temperature, low-humidity environment of 15°C and 10% relative humidity, and the density difference evaluation was also good.

[0162] (Comparative Example 1) A toner supply roller T-E1 was fabricated in the same manner as in Example 1, using commercially available product B-E1; (2-hydroxyethyl)triphenylphosphonium chloride (manufactured by Fujifilm Wako Pure Chemical Industries) as material (B). The ionic compound used here has a hydroxyl group and does not contain a nitrogen-containing heteroaromatic ring structure, but it does contain a benzene ring structure formed only of carbon. Therefore, it is incorporated into the urethane molecule, but the incorporated urethane molecule contains only a carbon-only aromatic ring structure and does not contain a nitrogen-containing heteroaromatic ring structure. As a result, the effects seen in the example were not observed, and as shown in Table 2, the resistance increased significantly during long-term operation, and the density difference in the image was also large.

[0163] (Reference Examples 1 and 2) This disclosure solves the problems that arise when using highly conductive carbon nanotubes (CNTs). Reference Examples 1 and 2 demonstrate that these problems do not occur when using carbon other than CNTs. The types of material (a) and material (b) were changed as shown in Table 1. In Reference Example 1, graphite (CSP-E, manufactured by Nippon Graphite Industries) was used as material (a). Like carbon nanotubes (CNTs), graphite has π-orbital electrons, and adsorption occurs through π-π interactions with its nitrogen-containing heteroaromatic ring structure. In Reference Example 2, material (a) was graphite (same as above), and material (b) was the commercially available product B-E1; (2-hydroxyethyl)triphenylphosphonium chloride (manufactured by Fujifilm Wako Pure Chemical Industries), which was also used in Comparative Example 1. Otherwise, toner supply rollers T-R1 and T-R2 were manufactured in the same manner as in Example 1.

[0164] The toner supply rollers according to any of Reference Examples 1 and 2 each have a conductive elastic layer containing graphite instead of CNT. Since graphite has lower conductivity than CNT, even when aggregated, local charge transfer does not occur, and no electrostatic force due to the accompanying electric field concentration occurs, nor does the desorption of graphite occur. Therefore, as shown in Table 2, although the increase in resistance is small, the original resistance value is high, and good images could not be obtained. In particular, since several hundred times higher conductivity is required to make the resistance value equivalent to that when using CNT, it was impossible to control it visually. In Reference Example 1, adsorption is induced by the π-π interaction between graphite and the nitrogen-containing heterocyclic structure. However, both Reference Example 2 without such interaction and Reference Example 1 do not exhibit as high conductivity as CNT, so the problems that occur when using CNT itself occur and do not occur.

[0165] [Table 1] In Table 1, SG101 indicates ZEONANO SG101 manufactured by Zeon. d indicates the values corresponding to d1 to d3 in Structural Formulas (1) to (3).

[0166] [Table 2] In Table 2, the cell diameter is the average cell diameter. The long side length and the short side length indicate the number average values. For example, the description of 6.00E+06 indicates 6.00×10 6 as shown.

[0167] The present disclosure relates to the following configurations. (Configuration 1) A conductive elastic roller having a conductive substrate and a conductive elastic layer on the substrate, where the conductive elastic layer contains polyurethane and carbon nanotubes, and the polyurethane contains a nitrogen-containing heteroaromatic ring structure, characterized by the conductive elastic roller. (Configuration 2) The conductive elastic roller according to configuration 1, wherein the nitrogen-containing heteroaromatic ring structure has a cation structure formed by the nitrogen-containing heteroaromatic ring. (Composition 3) The conductive elastic roller according to configuration 1 or 2, wherein the nitrogen-containing heteroaromatic ring structure is at least one cationic nitrogen-containing heteroaromatic ring structure selected from the group consisting of imidazolium cation, pyridinium cation, pyrazinium cation, pyrimidinium cation, azepinium cation, quinolinium cation, isoquinolinium cation, indolinium cation, quinoxalinium cation, triazolium cation, triazinium cation, and thiazolinium cation. (Composition 4) The nitrogen-containing heteroaromatic ring structure has a cation structure formed by the nitrogen-containing heteroaromatic ring. , A conductive elastic roller according to any one of configurations 1 to 3, wherein the cation structure has at least one cation structure selected from the group consisting of the structure shown in the following structural formula (1), the structure shown in the following structural formula (2), and the structure shown in the following structural formula (3). TIFF2026131439000017.tif47153 [In structural formula (1), R1 and R2 each represent hydrocarbon groups necessary to form a nitrogen-containing heteroaromatic five-membered ring together with the nitrogen atom to which they are bonded, and d1 represents an integer of 0 or 1. Z1 to Z3 each independently represent the structure shown in structural formula (Z101), the structure shown in structural formula (Z102), the structure shown in structural formula (Z103), a hydrogen atom, or a hydrocarbon group having 1 to 4 carbon atoms. However, at least one of Z1 to Z3 is the structure shown in structural formula (Z101), the structure shown in structural formula (Z102), or the structure shown in structural formula (Z103).] TIFF2026131439000018.tif52153 [In structural formula (2), R3 and R4 each represent hydrocarbon groups necessary to form a nitrogen-containing heteroaromatic six-membered ring together with the nitrogen atom to which they are bonded. d2 represents an integer from 0 to 2, and when d2 is 2, Z5 may be the same or different. Z4 and Z5 each independently represent the structure shown in structural formula (Z101), the structure shown in structural formula (Z102), the structure shown in structural formula (Z103), a hydrogen atom, or a hydrocarbon group having 1 to 4 carbon atoms. However, at least one of Z4 and Z5 is the structure shown in structural formula (Z101), the structure shown in structural formula (Z102), or the structure shown in structural formula (Z103).] TIFF2026131439000019.tif48153 [In structural formula (3), R5 represents a hydrocarbon group necessary to form a nitrogen-containing heteroaromatic ring together with the bonded nitrogen atom, and d3 represents an integer of 0 or 1. Z6 and Z7 each independently represent the structure shown in structural formula (Z101), the structure shown in structural formula (Z102), the structure shown in structural formula (Z103), a hydrogen atom, or a hydrocarbon group having 1 to 4 carbon atoms. However, at least one of Z6 and Z7 is the structure shown in structural formula (Z101), the structure shown in structural formula (Z102), or the structure shown in structural formula (Z103).] TIFF2026131439000020.tif102153 [In structural formulas (Z101), (Z102), and (Z103), R101, R102, and R103 each independently represent a divalent hydrocarbon group having a straight chain or branching. The symbol "*" represents a bond with a nitrogen atom or carbon atom constituting the nitrogen-containing heteroaromatic five-membered ring in structural formula (1), a bond with a nitrogen atom or carbon atom constituting the nitrogen-containing heteroaromatic six-membered ring in structural formula (2), or a bond with a nitrogen atom or carbon atom constituting the nitrogen-containing heteroaromatic ring in structural formula (3). The symbol "**" represents a bond with a carbon atom in the polymer chain of the polyurethane.] (Composition 5) The conductive elastic roller according to configuration 4, wherein the cation structure is represented by the following structural formula (4). TIFF2026131439000021.tif44153 [In structural formula (4), d1 represents an integer of 0 or 1, and Z1 to Z3 each independently represent the structure. Z101 represents the structure shown by formula (Z101), the structure shown by structural formula (Z102), the structure shown by structural formula (Z103), a hydrogen atom, or a hydrocarbon group having 1 to 4 carbon atoms. However, at least one of Z1 to Z3 is the structure shown by structural formula (Z101), the structure shown by structural formula (Z102), or the structure shown by structural formula (Z103). (Composition 6) The polyurethane contains an anion, A conductive elastic roller according to any one of configurations 1 to 5, wherein the anion comprises at least one anion selected from the group consisting of fluoroalkylsulfonylimide anion, fluorosulfonylimide anion, fluoroalkyl sulfonate anion, fluorosulfonate anion, fluoroalkyl carboxylic acid anion, fluoroalkylmethide anion, fluoroborate anion, fluorophosphate anion, dicyanamide anion, and thiocyanate anion. (Composition 7) The conductive elastic roller according to configuration 6, wherein the anion comprises at least one anion selected from the group consisting of bis(fluorosulfonyl)imide anion and bis(trifluoromethanesulfonyl)imide anion. (Composition 8) The conductive elastic layer has an average cell diameter of 100-500 μm and a cell count of 50-300 cells / inch on its surface. 2 A conductive elastic roller according to any one of configurations 1 to 7, which is a foamed elastic layer having voids. (Composition 9) The number average length of the carbon nanotube in the short-side direction is 2.0 to 50.0 nm. A conductive elastic roller according to any of configurations 1 to 8, wherein the number average value of the length of the carbon nanotube in the long-side direction is 10 to 2000 μm. (Composition 10) A process cartridge that is detachably configured to be attached to the main body of an electrophotographic image forming apparatus, A process cartridge characterized in that the process cartridge comprises a conductive elastic roller as described in any of configurations 1 to 9. (Composition 11) An electrophotographic image forming apparatus characterized by comprising a conductive elastic roller as described in any of configurations 1 to 9. [Explanation of symbols]

[0168] 1. Conductive elastic roller, 2. Substrate, 3. Conductive elastic layer, 15 Toner, 16 Developer roller, 17 Process cartridge, 18 Photoreceptor (electrophotographic photoreceptor), 19 Toner supply roller, 20 Toner container, 21 Developer blade, 22 Developer unit, 37 Cylindrical metal, 38 Conductive bearing, 39 High-voltage power supply, 40 Voltmeter, 41 Nip regulating member

Claims

1. A conductive elastic roller having a conductive substrate and a conductive elastic layer on the substrate, The conductive elastic layer comprises polyurethane and carbon nanotubes. A conductive elastic roller characterized in that the polyurethane contains a nitrogen-containing heteroaromatic ring structure.

2. The conductive elastic roller according to claim 1, wherein the nitrogen-containing heteroaromatic ring structure has a cation structure formed by the nitrogen-containing heteroaromatic ring.

3. The conductive elastic roller according to claim 1, wherein the nitrogen-containing heteroaromatic ring structure is at least one cationic nitrogen-containing heteroaromatic ring structure selected from the group consisting of imidazolium cation, pyridinium cation, pyrazinium cation, pyrimidinium cation, azepinium cation, quinolinium cation, isoquinolinium cation, indolinium cation, quinoxalinium cation, triazolium cation, triazinium cation, and thiazolinium cation.

4. The nitrogen-containing heteroaromatic ring structure has a cation structure formed by the nitrogen-containing heteroaromatic ring, The conductive elastic roller according to claim 1, wherein the cation structure has at least one cation structure selected from the group consisting of the structure shown in the following structural formula (1), the structure shown in the following structural formula (2), and the structure shown in the following structural formula (3). 【Chemistry 1】 [In structural formula (1), R1 and R2 each represent hydrocarbon groups necessary to form a nitrogen-containing heteroaromatic five-membered ring together with the nitrogen atom to which they are bonded, and d1 represents an integer of 0 or 1. Z1 to Z3 each independently represent the structure shown in structural formula (Z101), the structure shown in structural formula (Z102), the structure shown in structural formula (Z103), a hydrogen atom, or a hydrocarbon group having 1 to 4 carbon atoms. However, at least one of Z1 to Z3 is the structure shown in structural formula (Z101), the structure shown in structural formula (Z102), or the structure shown in structural formula (Z103).] 【Chemistry 2】 [In structural formula (2), R3 and R4 each represent hydrocarbon groups necessary to form a nitrogen-containing heteroaromatic six-membered ring together with the nitrogen atom to which they are bonded. d2 represents an integer from 0 to 2, and when d2 is 2, Z5 may be the same or different. Z4 and Z5 each independently represent the structure shown in structural formula (Z101), the structure shown in structural formula (Z102), the structure shown in structural formula (Z103), a hydrogen atom, or a hydrocarbon group having 1 to 4 carbon atoms. However, at least one of Z4 and Z5 is the structure shown in structural formula (Z101), the structure shown in structural formula (Z102), or the structure shown in structural formula (Z103).] 【Transformation 3】 [In structural formula (3), R5 represents a hydrocarbon group necessary to form a nitrogen-containing heteroaromatic ring together with the bonded nitrogen atom, and d3 represents an integer of 0 or 1. Z6 and Z7 each independently represent the structure shown in structural formula (Z101), the structure shown in structural formula (Z102), the structure shown in structural formula (Z103), a hydrogen atom, or a hydrocarbon group having 1 to 4 carbon atoms. However, at least one of Z6 and Z7 is the structure shown in structural formula (Z101), the structure shown in structural formula (Z102), or the structure shown in structural formula (Z103).] 【Chemistry 4】 [In structural formulas (Z101), (Z102), and (Z103), R101, R102, and R103 each independently represent a divalent hydrocarbon group having a straight chain or branching. The symbol "*" represents a bond with a nitrogen atom or carbon atom constituting the nitrogen-containing heteroaromatic five-membered ring in structural formula (1), a bond with a nitrogen atom or carbon atom constituting the nitrogen-containing heteroaromatic six-membered ring in structural formula (2), or a bond with a nitrogen atom or carbon atom constituting the nitrogen-containing heteroaromatic ring in structural formula (3). The symbol "**" represents a bond with a carbon atom in the polymer chain of the polyurethane.]

5. The conductive elastic roller according to claim 4, wherein the cation structure is represented by the following structural formula (4). 【Transformation 5】 [In structural formula (4), d1 represents an integer of 0 or 1, and Z1 to Z3 each independently represent the structure shown in structural formula (Z101), the structure shown in structural formula (Z102), the structure shown in structural formula (Z103), a hydrogen atom, or a hydrocarbon group having 1 to 4 carbon atoms. However, at least one of Z1 to Z3 is the structure shown in structural formula (Z101), the structure shown in structural formula (Z102), or the structure shown in structural formula (Z103).]

6. The polyurethane contains an anion, The conductive elastic roller according to claim 1, wherein the anion comprises at least one anion selected from the group consisting of fluoroalkylsulfonylimide anion, fluorosulfonylimide anion, fluoroalkyl sulfonate anion, fluorosulfonate anion, fluoroalkyl carboxylic acid anion, fluoroalkylmethide anion, fluoroborate anion, fluorophosphate anion, dicyanamide anion, and thiocyanate anion.

7. The conductive elastic roller according to claim 6, wherein the anion comprises at least one anion selected from the group consisting of bis(fluorosulfonyl)imide anion and bis(trifluoromethanesulfonyl)imide anion.

8. The conductive elastic layer has an average cell diameter of 100 to 500 μm and 50 to 300 cells per inch on its surface. ２ A conductive elastic roller according to claim 1, wherein the foamed elastic layer has voids.

9. The number average length of the carbon nanotube in the short-side direction is 2.0 to 50.0 nm. The conductive elastic roller according to claim 1, wherein the number average value of the length of the carbon nanotube in the long-side direction is 10 to 2000 μm.

10. A process cartridge that is detachably configured to be attached to the main body of an electrophotographic image forming apparatus, A process cartridge characterized in that it comprises a conductive elastic roller as described in any one of claims 1 to 9.

11. An electrophotographic image forming apparatus characterized by comprising a conductive elastic roller according to any one of claims 1 to 9.

Images