Electrophotographic belt and electrophotographic image forming apparatus

Abstract

An electrophotographic belt with suppressed bleeding, high conductivity, and minimal conductivity unevenness. [Solution] An electrophotographic belt having a base layer, the base layer containing a polymer ionic conductive agent having a repeating structure containing cations and anions, a block copolymer containing segments having ester groups and segments having amide groups in the molecular chain, and polyester.

Description

[Technical Field]

[0001] This disclosure relates to an electrophotographic belt and an electrophotographic image forming apparatus. [Background technology]

[0002] In an electrophotographic image forming apparatus (hereinafter also referred to as "electrophotographic apparatus"), an electrostatic image carrier, such as a photosensitive drum, is charged, and an electrostatic latent image is formed by exposing the charged electrostatic image carrier to light. Subsequently, the electrostatic latent image is developed by triboelectrically charged toner, and the toner image is transferred and fixed to a recording medium such as paper, thereby forming a desired image on the recording medium. As a transfer method for electrophotographic devices, an intermediate transfer method is known in which an unfixed toner image on an electrostatic image carrier is first transferred to an intermediate transfer medium by an electric current supplied from a transfer power supply, and then the unfixed toner image is secondarily transferred from the intermediate transfer medium to a recording medium. Such an intermediate transfer method is particularly used in color electrophotographic devices.

[0003] In color electrophotographic devices, four toners (yellow, magenta, cyan, and black) are sequentially transferred from the image forming units of each color onto an intermediate transfer medium, and the resulting composite image is transferred to the recording medium all at once. This offers advantages such as faster printing and higher image quality. In recent years, with the increasing need for greater durability in copiers and printers, research has been conducted to extend the lifespan of intermediate transfer materials. Since an electric current is passed through the intermediate transfer material during primary and secondary transfer, the intermediate transfer material may contain an ionic conductive agent to control its resistivity to an appropriate level. However, when an electric current is passed through it, the ionic conductive agent may seep out onto the surface of the intermediate transfer material and adhere to the surface of the electrophotographic photoreceptor in contact with it. To address the problem of ionic conductive agent bleeding and contaminating the contact material, Patent Document 1 discloses that bleeding can be suppressed by using a polymer ionic conductive agent, which is a polymerized form of the ionic conductive agent. [Prior art documents] [Patent Documents]

[0004] [[Patent Document 1]] Japanese Patent Application Laid-Open No. 2012-208226 [[Summary of the Invention]] [[Problems to be Solved by the Invention]]

[0005] According to the description of Patent Document 1, bleeding can be suppressed by adding a polymer ionic conductive agent to rubber. However, the inventors of the present invention recognized that when a polymer ionic conductive agent was added to the polyester used in the intermediate transfer member, the conductivity decreased and conductivity unevenness occurred. As a result of the occurrence of conductivity unevenness, image unevenness is likely to occur. This is considered to be due to poor dispersion of the polymer ionic conductive agent in the polyester.

[0006] The present disclosure provides an electrophotographic belt in which bleeding is suppressed, the conductivity is high, and the conductivity unevenness is small. The present disclosure also provides an electrophotographic image forming apparatus including the electrophotographic belt. [[Means for Solving the Problems]]

[0007] The present disclosure relates to an electrophotographic belt having a base layer, wherein the base layer contains a polymer ionic conductive agent having a repeating structure containing a cation and an anion, a block copolymer containing a segment having an ester group and a segment having an amide group in a molecular chain, a polyester, and relates to an electrophotographic belt. [[Effects of the Invention]]

[0008] According to the present disclosure, an electrophotographic belt in which bleeding is suppressed, the conductivity is high, and the conductivity unevenness is small can be provided. Further, according to the present disclosure, an electrophotographic image forming apparatus including the electrophotographic belt can be provided. [[Brief Description of the Drawings]]

[0009] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of a full-color electrophotographic image forming apparatus. [Figure 2] FIG. 2 is a schematic cross-sectional view of the injection molding apparatus used in the examples. [Figure 3] FIGS. 3A to 3D are schematic cross-sectional views of the blow molding apparatus used in the examples. [Figure 4] FIG. 4 is a schematic cross-sectional view of the heat treatment apparatus for the blow bottle used in the examples. [Figure 5] FIGS. 5A to 5C are explanatory views of a configuration example of the electrophotographic belt according to the present disclosure. [Figure 6] FIG. 6 shows the results of infrared spectroscopic measurement in Example 1.

BEST MODE FOR CARRYING OUT THE INVENTION

[0010] In the present disclosure, descriptions such as "XX or more and YY or less" and "XX to YY" representing a numerical range mean a numerical range including the lower limit and the upper limit which are endpoints, unless otherwise specified. When numerical ranges are described stepwise, the upper limit and the lower limit 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.

[0011] The inventors of the present invention have repeatedly studied the suppression of bleeding of the ionic conductive agent from the electrophotographic belt. When a polymer ionic conductive agent was added to polyester which is a matrix resin, although bleeding was improved, the conductivity decreased and conductivity unevenness occurred. The inventors of the present invention speculated on the reason as follows.

[0012] When polyester and polymer ionic conductive agents are melt-mixed, they form a sea-island structure where the polyester is the "sea" and the polymer ionic conductive agent is the "island." Polyester and polymer ionic conductive agents do not mix well, and the polymer ionic conductive agent does not disperse easily within the polyester. In other words, the polymer ionic conductive agent does not spread throughout the entire electrophotographic belt, but exists as a large island.

[0013] Because there are no connections between the islands, there are fewer conductive paths, resulting in low conductivity of the electrophotographic belt. Furthermore, the island areas have low resistivity while the sea areas have high resistivity, leading to greater conductivity unevenness in the electrophotographic belt. Therefore, the inventors recognized the need to finely disperse a polymer ionic conductive agent in the polyester.

[0014] Based on this understanding, the inventors conducted further studies and found that it is important to include a block copolymer containing segments having ester groups and segments having amide groups in the molecular chain in the electrophotographic belt. The presence of this block copolymer allows the polymer ionic conductive agent to be finely dispersed in the polyester, suppressing bleeding, increasing conductivity, and reducing conductivity unevenness.

[0015] The inventors consider the following reason for this: The oxygen atoms of the amide groups present in the molecular chains of the block copolymer are negatively charged. Therefore, they are electrostatically attracted to the cation-containing repeating structure of the polymer ionic conductive agent, resulting in good compatibility with the polymer ionic conductive agent. Furthermore, because the block copolymer has ester groups in its molecular chains, it also has good compatibility with the polyester matrix resin.

[0016] Therefore, the presence of a block copolymer containing segments with ester groups and segments with amide groups in the molecular chain, in addition to the polymer ionic conductive agent and polyester, allows the polymer ionic conductive agent to be finely dispersed in the polyester. As a result, bleeding is suppressed while conductivity is increased, and conductivity unevenness can also be suppressed. The embodiments of the electrophotographic belt relating to this disclosure are described in detail below. However, this disclosure is not limited to the embodiments described below.

[0017] <Electrophotographic belt> The electrophotographic belt related to this disclosure will be described in detail below. An electrophotographic belt according to one aspect of the present disclosure has a base layer. The base layer is, for example, a biaxially oriented cylindrical film. The base layer comprises a polymer ionic conductive agent having a repeating structure containing cations and anions, a block copolymer containing segments having ester groups and segments having amide groups in its molecular chain, and a polyester. The base layer may be a molded article of a conductive resin composition comprising a polymer ionic conductive agent having a repeating structure containing cations and anions, a block copolymer containing segments having ester groups and segments having amide groups in its molecular chain, and a polyester. The electrophotographic belt may have other components (e.g., a surface layer) in addition to the base layer. The electrophotographic belt may also consist only of the base layer.

[0018] Figure 5A shows a perspective view of an electrophotographic belt 500 having an endless belt shape according to one aspect of the present disclosure. An example of a layer configuration is a single-layer (monolayer) structure in which the cross section of line AA' in Figure 5A is composed only of a base layer 501 containing the conductive resin composition described above, as shown in Figure 5B. In this case, the outer surface 500-1 of the base layer 501 becomes the toner-carrying surface (outer surface) of the electrophotographic belt.

[0019] Another example of a layered structure is one in which the cross-section of line AA' has a laminated structure having a base layer 501 and a second layer (surface layer) 502 that covers the outer surface of the base layer 501, as shown in Figure 5C. When the second layer 502 is provided, the outer surface 500-1 of the second layer 502 becomes the toner-carrying surface of the electrophotographic belt. One of the functions of the second layer is to improve the release properties of the toner.

[0020] 1. Base layer An endless base layer according to one aspect of this disclosure includes a polymer ionic conductive agent having a repeating structure containing cations and anions, a block copolymer containing segments having ester groups and segments having amide groups in its molecular chain, and a polyester. Each material is described in detail below.

[0021] (Polymer ionic conductive agent having a repeating structure containing cations and anions) The base layer contains a polymer ionic conductive agent having a repeating structure containing cations and anions. The polymer ionic conductive agent contains both cations and anions. Ionic liquids are sometimes used as ionic conductive agents, but because ionic liquids have a monomolecular structure, they are prone to bleeding. Therefore, by polymerizing only the cations, it is possible to suppress bleeding.

[0022] The repeating structure containing cations is, for example, a cationic polymer. The cationic polymer is not particularly limited, and known ones can be used. The cation in the repeating structure containing cations is preferably at least one selected from the group consisting of a cation having an imidazolium structure, a cation having a pyridinium structure, a cation having a quaternary ammonium structure, and a cation having a quaternary phosphonium structure. The cation is more preferably a quaternary ammonium cation.

[0023] Polymerization of cations is possible by radical polymerization of ionic liquids. Radical polymerization can be performed on any ionic liquid that has a vinyl group or an allyl group in the cation, and there are no particular restrictions on the anion.

[0024] The cation of the ionic liquid is preferably at least one compound selected from the group consisting of, for example, the compound represented by formula (1), the compound represented by formula (2), and the compound represented by formula (3). The structures of polymer ionic conductive agents obtained by radical polymerization of ionic liquids having these structures are shown in formulas (4) to (6).

[0025] The repeating structure containing the cation is preferably at least one structure selected from the group consisting of the structure represented by formula (4), the structure represented by formula (5), and the structure represented by formula (6), with the structure represented by formula (6) being more preferred. It is even more preferable that the repeating structure containing the cation is polydiallyldimethylammonium.

[0026] [ka]

[0027] [ka]

[0028] R1 to R4 each independently represent a hydrogen atom, a hydrocarbon group having 1 to 18 carbon atoms (preferably 1 to 6, more preferably 1 to 3, even more preferably 1 or 2, and especially preferably 1) (preferably an alkyl group), or an alkoxy group having 1 to 18 carbon atoms (preferably 1 to 6, more preferably 1 to 3, even more preferably 1 or 2, and especially preferably 1). The cations listed above may be used individually or in combination of two or more. Furthermore, the hydrocarbon groups of R1 to R4 may be linear or branched, and may contain cyclic structures or unsaturated bonds. In addition, it is preferable that the structure has low steric hindrance during radical polymerization.

[0029] n, m, and l each independently represent an integer of 10 or more. From the viewpoint of suppressing bleeding, it is preferable that n, m, and l each independently be 10 or more, more preferably 100 or more, even more preferably 500 or more, and even more preferably 800 or more. There is no particular upper limit, but it is preferable that n, m, and l each independently be 5000 or less, more preferably 4000 or less, even more preferably 3000 or less, and even more preferably 2000 or less.

[0030] The degree of polymerization of the polymer ionic conductive agent can be measured, for example, by gel permeation chromatography. Cut out a 1 mm square of the electrophotographic belt, immerse it in a solvent capable of dissolving the polymer ionic conductive agent, and remove the electrophotographic belt. Remove the solvent and isolate the polymer ionic conductive agent. Dissolve the isolated polymer ionic conductive agent in 1,1,1,3,3,3-hexafluoro-2-propanol in which 1 mmol of sodium trifluoroacetate has been dissolved in advance to a concentration of 1 mg / mL. Measure the prepared sample solution with a gel permeation chromatography apparatus (HLC-8320GPC, manufactured by Tosoh Corporation) to obtain the molecular weight. It is possible to calculate the degree of polymerization from the obtained molecular weight.

[0031] Next, the anion of the polymer ionic conductive agent is not particularly limited, and known ones can be used. The anion is a tetrafluoroborate anion, a hexafluorophosphate anion, a bis(trifluoromethanesulfonyl)imide anion (CF3SO2)2N - , a bis(fluorosulfonyl)imide anion (FSO2)2N - , a chloride ion Cl - , AlCl4 - , Al2Cl7 - , NO3 - , BF4 - , PF6 - , CH3COO - , CF3COO - , CF3SO3 - , (CF3SO2)3C - , AsF6 - , SbF6 - , F(HF)n - , CF3CF2CF2CF2SO3 - , (CF3CF2SO2)2N - , CF3CF2CF2COO - and at least one selected from the group consisting of the like.

[0032] The anion is preferably one ion selected from the group consisting of chloride ions and fluorine-containing sulfonylimid ions, and more preferably a fluorine-containing sulfonylimid ion. The fluorine-containing sulfonylimid ion is bis(trifluoromethanesulfonyl)imide anion (CF3SO2)2N - , bis(fluorosulfonyl)imido anion (FSO2) 2N - At least one selected from the group consisting of is preferred.

[0033] The anion is preferably at least one anion selected from the group consisting of, for example, the anion represented by formula (7), the anion represented by formula (8), and the anion represented by formula (9).

[0034] [ka]

[0035] The polymer ionic conductive agent is preferably composed of a combination of one or more cations and anions as listed above. Among these combinations, it is preferable to use a polymer ionic conductive agent with low hygroscopicity.

[0036] The content of the polymer ionic conductive agent in the base layer is, for example, 0.08 to 6.0% by mass, preferably 0.09 to 2.0% by mass, more preferably 0.09 to 1.2% by mass, and even more preferably 0.1 to 1.0% by mass. Within this range, bleeding is more easily suppressed, and conductivity unevenness is also more easily suppressed.

[0037] (A block copolymer containing segments having ester groups and segments having amide groups in the molecular chain) The polymer used to disperse the polymer ion conductive agent in the polyester matrix resin is high The material needs to contain amide groups that are compatible with molecular ionic conductive agents and ester groups that are compatible with polyesters. Therefore, the base layer contains a block copolymer containing segments having ester groups and segments having amide groups in the molecular chain. Furthermore, from the viewpoint of conductivity, it may also contain ether groups.

[0038] The block copolymer is, for example, a copolymer having ester groups and amide groups in its molecular chain, and may further have ether groups. Such block copolymers are not particularly limited, and known ones can be used. The block copolymer is preferably a polyesteramide or a polyether esteramide.

[0039] The presence of polyesteramide or polyether esteramide around the polymer ionic conductive agent enables uniform dispersion of the polymer ionic conductive agent within the polyester. Known polyesteramides and polyether esteramides can be used. Commercially available polyesteramides or polyether esteramides may also be used, such as the TPAE series (manufactured by T&K TOKA Corporation), including TPAE-12 and TPAE-617 (both trade names).

[0040] The content of the block copolymer in the base layer is, for example, 1.0 to 30.0% by mass, preferably 2.0 to 20.0% by mass, more preferably 2.5 to 16.0% by mass, and even more preferably 2.8 to 15.0% by mass. Within this range, bleeding is more easily suppressed, and conductivity unevenness is also more easily suppressed.

[0041] From the viewpoint of uniformly dispersing the polymer ionic conductive agent, the content of the block copolymer in the base layer is, for example, 2 to 200 times, preferably 2.5 to 160 times, and more preferably 2.6 to 150 times, relative to the mass of the polymer ionic conductive agent. Within this range, the polymer ionic conductive agent is more easily dispersed uniformly, the surface resistivity does not increase easily, and conductivity unevenness is more easily suppressed.

[0042] The functional groups contained in polyesteramides and polyether ester amides can be analyzed by measuring infrared absorption spectra. Isolation from the electrophotographic belt is performed by solvent extraction. The solvent used for extraction can be any solvent that dissolves polyesteramides or polyether ester amides, such as ethanol, tetrahydrofuran, or methyl ethyl ketone. After extraction, the solvent is removed from the solution, and the infrared absorption spectrum of the residue is measured.

[0043] In infrared spectroscopy measurements using block copolymers as samples, the absorbance and peak intensity ratios of ester groups, amide groups, and ether groups are defined as follows. Absorbance A, ester group, wavenumber 1735 cm⁻¹ -1 Absorbance of the peak top in absorption (C=O stretching motion) Absorbance B, amide group, wavenumber 1635 cm⁻¹ -1 Absorbance of the peak top in absorption (C=O stretching motion) Absorbance C, ether group, wavenumber 1100 cm⁻¹ -1 Absorbance of the peak top in absorption (CO expansion and contraction motion)

[0044] Then, the peak intensity ratios for the ester group, amide group, and ether group are calculated using the following formulas. Peak intensity ratio of ester group = [Absorbance A / (Absorbance A + Absorbance B + Absorbance C)] Amide group peak intensity ratio = [Absorbance B / (Absorbance A + Absorbance B + Absorbance C)] Peak intensity ratio of the ether group = [absorbance C / (absorbance A + absorbance B + absorbance C)]

[0045] In this case, the peak intensity ratio of ester groups in the block copolymer is, for example, 0.08 to 0.25, preferably 0.10 to 0.22, and more preferably 0.11 to 0.21. The peak intensity ratio of amide groups in the block copolymer is, for example, 0.27 to 0.70, preferably 0.32 to 0.65, and more preferably 0.35 to 0.62. The peak intensity ratio of ether groups in the block copolymer is, for example, 0.10 to 0.60, preferably 0.15 to 0.55, and more preferably 0.18 to 0.53. By being within the above range, the effect of finely dispersing the polymer ionic conductive agent is more easily obtained. The peak intensity ratio of ester groups in the block copolymer is particularly preferably 0.12. The peak intensity ratio of amide groups in the block copolymer is particularly preferably 0.37. The peak intensity ratio of ether groups in the block copolymer is particularly preferably 0.51.

[0046] (polyester) The base layer contains polyester. The polyester is not particularly limited and known polyesters can be used. Examples of polyesters include polycondensates of dicarboxylic acids and diols, polycondensates of oxycarboxylic acids or lactones, or polycondensates using multiple of these components. Further polyfunctional monomers may be used in combination.

[0047] The polyester may be crystalline polyester or amorphous polyester, but crystalline polyester is preferred. The crystalline polyester may be a homopolyester containing one type of ester bond, or a copolyester (polymer) containing multiple ester bonds.

[0048] The polyester is preferably at least one polyester selected from the group consisting of polyalkylene terephthalate and polyalkylene naphthalate, which exhibit excellent heat resistance, copolymers of polyalkylene terephthalate and polyalkylene naphthalate, and copolymers of polyalkylene naphthalate and polyalkylene isophthalate. The polyester is more preferably at least one polyester selected from the group consisting of polyalkylene terephthalate and polyalkylene naphthalate. Such polyesters are more likely to achieve low costs.

[0049] In polyalkylene terephthalate, polyalkylene naphthalate, and polyalkylene isophthalate, the number of carbon atoms in the alkylene is preferably 2 to 16 (more preferably 2 to 4) from the viewpoint of obtaining high crystallinity and heat resistance.

[0050] More specifically, the polyester is preferably at least one polyester selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, and polyethylene isophthalate, as well as modified polyethylene terephthalate, modified polyethylene naphthalate, and modified polyethylene isophthalate, which are obtained by modifying some of these blocks with other blocks. Other blocks include monomer units consisting of at least one compound selected from the group consisting of 1,4-naphthalenedicarboxylic acid and 2,3-naphthalenedicarboxylic acid. One of these can be used alone, or two or more can be used in combination. They may be blends or alloys, and other resins may be added. The polyester is more preferably at least one polyester selected from the group consisting of polyethylene terephthalate and polyethylene naphthalate, and even more preferably polyethylene naphthalate.

[0051] The polyester content in the base layer is, for example, 70.0 to 98.0% by mass, and is preferable. The mass is approximately 80.0 to 97.0%, and more preferably 83.0 to 90.0%. Within this range, bleeding is more easily suppressed, and conductivity unevenness is also more easily suppressed.

[0052] The transferability of toner fundamentally depends on the electrical properties of the base layer. Furthermore, to obtain high-quality electrophotographic images, the surface resistivity of the base layer should be, for example, 1.0 × 10⁻⁶. 3 Ω / □~1.0×10 13 It is preferable that the ratio is Ω / □, and 1.0 × 10 3 Ω / □~1.0×10 12 A surface resistivity of Ω / □ is more preferable. 3 If the resistance is Ω / □ or greater, it prevents the resistance from becoming excessively low, makes it easy to obtain the transfer field, and effectively suppresses image defects and graininess. Surface resistivity of 1.0 × 10⁻⁶ 13 If the value is less than or equal to Ω / □, excessive transfer voltage can be more effectively suppressed, effectively preventing the need for larger power supplies and increased costs.

[0053] The thickness of the base layer is not particularly limited. However, the electrophotographic belt is positioned in a bent state within the electrophotographic image forming apparatus. Therefore, from the viewpoint of ensuring flexibility, the thickness of the base layer is preferably, for example, 40 μm to 500 μm, and more particularly, 50 μm to 100 μm.

[0054] The above-mentioned base layer can be manufactured, for example, through the following steps (i) to (iii). Step (i): The above materials are melted and kneaded to obtain a conductive resin composition. Step (ii): Obtain a test tube-shaped preform made of a conductive resin composition. Step (iii): The preform is stretched in its longitudinal direction and gas is introduced into the preform to stretch and mold it in two axes, longitudinal and circumferential, to obtain a biaxially stretched product (hereinafter also called a "blow bottle") (biaxial stretch blow molding). Step (iv): Both ends of the blow bottle are cut to obtain a base layer which is an endless biaxially oriented cylindrical film.

[0055] In step (i), a polymer ionic conductive agent, a polyether ester amide or polyester amide, and a polyester are subjected to hot-melt kneading. The temperature and time during hot-melt kneading are not particularly limited and should be controlled within a range in which a uniform composition can be obtained. The temperature during hot-melt kneading is preferably, for example, 190 to 330°C, and more preferably 220 to 270°C. The time is preferably, for example, 3 to 5 minutes. This is because the polymer ionic conductive agent can be uniformly kneaded and thermal degradation of the resin can be prevented. It is preferable to pelletize the obtained conductive resin composition.

[0056] In this way, by preparing a conductive resin composition, a polymer ionic conductive agent can be uniformly dispersed in the resin. This can increase the conductivity of the biaxially oriented cylindrical film and suppress conductivity unevenness.

[0057] In step (ii), a test tube-shaped preform is molded using the obtained conductive resin composition. There are no particular restrictions on the method of molding the preform, and for example, the following method can be used. As shown in Figure 2, the molten conductive resin composition is injected into a preform molding die consisting of a cavity mold 203 and a core mold 207 using an injection molding apparatus 201, and solidified in the preform molding die to form a preform 205 having a predetermined shape. In other words, it is preferable to mold the preform using a mold. The injection molding temperature is not particularly limited and can be changed as appropriate depending on the polyester used. For example, it is about 200 to 350°C.

[0058] Furthermore, it is preferable that the temperature of the preform molding die into which the molten material is injected is, for example, 40°C or lower (more preferably 20-40°C). The molten material is cooled and solidified within the mold, but rapid cooling at this stage prevents the crystallization of polyester from progressing. By suppressing the crystallization of polyester within the preform, the biaxial crystal orientation of polyester during stretch blow molding in process (iii) can be controlled more precisely. The size of the preform is not particularly limited; a size appropriate to the desired electrophotographic belt shape should be selected.

[0059] Next, in step (iii), the preform is subjected to biaxial stretch blow molding. First, as shown in Figure 3A, the preform 205 is placed in the heating furnace 301 and heated to a temperature at which it can be stretched. The heating time at this time is preferably 5 minutes or less, and more preferably 1 minute or less. By limiting the heating time to 5 minutes or less, it is possible to prevent the crystallization of crystalline polyester from progressing within the preform during heating.

[0060] The heated preform is transported in the direction of arrow 305. Next, the blow mold 303, which has a cylindrical cavity 303-3 formed inside by combining the left mold 303-1 and the right mold 303-2, is lowered from directly above the heated preform 205 in the direction of arrow 307. Then, as shown in Figure 3B, the preform 205 is placed at the opening of the blow mold 303.

[0061] Furthermore, it is preferable to place the heated preform at the mouth of the blow mold within a short time (e.g., within 20 seconds) so that the temperature of the preform does not drop before the start of the next biaxial stretching process. This prevents the crystallization of polyester within the preform from progressing due to slow cooling. The heating temperature of the preform may be calculated, for example, based on the endothermic peak and baseline shift during heating using differential scanning calorimetry (DSC) on the conductive resin composition that constitutes the preform, or it may be determined from the glass transition temperature (Tg).

[0062] The heated preform 205, placed inside the blow mold 303, is stretched in the longitudinal direction of the preform 205 by driving the stretching rod 309 in the direction of arrow 311, as shown in Figure 3C. This stretching is called primary stretching. Furthermore, gas is introduced into the preform 205 from its opening (arrow 313) in synchronization with the driving of the stretching rod 309, causing the preform to expand in its circumferential direction. This is called secondary stretching. Examples of gases to be blown in include air, nitrogen, carbon dioxide, and argon.

[0063] As a result, the preform 205 expands in the directions indicated by the arrows 315 in Figure 3C, adheres tightly to the inner wall of the cavity 303-3, and cools and solidifies in that state. Next, the bottle-shaped molded product (hereinafter also referred to as the "blow bottle") is removed from the blow mold 303 by separating the right mold 303-1 and the left mold 303-2 of the blow mold 303.

[0064] Next, in step (iv), as shown in Figure 3D, the portion of the blown bottle 317 on the mouth side and the portion of the upper end opposite to the mouth side are cut to obtain a biaxially oriented film 319 which will be the base layer.

[0065] Furthermore, if necessary, heat treatment may be performed before cutting the blow bottle 317 to adjust the surface roughness of the outer surface of the blow bottle and to fine-tune the crystallinity of the polyester. Specifically, for example, as shown in Figure 4, the blow bottle 317 is placed inside a cylindrical mold 401, and then gas is filled into the blow bottle. Then, in order to prevent the gas inside the blow bottle from leaking out, the mold 401 is heated while rotating it with a roller-shaped heater 403 that is in contact with the outer surface of the mold 401, with the outer mold 405 attached to the top and bottom of the mold 401. The heating temperature is, for example, about 130 to 190°C, and the heating time is, for example, the blow bottle Ensure that the entire surface is heated uniformly for approximately 60 seconds.

[0066] 2. Surface layer The electrophotographic belt may have a surface layer on the surface (e.g., the outer circumferential surface) of the base layer. An example of a surface layer is a layer with excellent wear resistance, which may include a cured product of an active energy ray curable resin. Such a surface layer can be provided, for example, by applying a composition containing an active energy ray curable resin, such as a photocurable resin, to the outer circumferential surface of the base layer and curing it.

[0067] Examples of active energy ray curable resins include, for example, acrylic resins. Conductive particles may also be added to adjust the surface resistivity of the surface layer. Examples of conductive particles include carbon black, graphite, carbon nanotubes, carbon microcoils, zinc oxide, and zinc antimonate.

[0068] Furthermore, a third layer (not shown) may be provided to cover the inner circumferential surface of the base layer 501. Examples of the third layer include, for example, a resin layer to reinforce the first layer and a conductive layer to make the inner circumferential surface of the electrophotographic belt conductive.

[0069] An electrophotographic belt is, for example, an intermediate transfer belt. However, the applications of the electrophotographic belt according to this disclosure are not limited to intermediate transfer belts; it can also be suitably used as, for example, a transport transfer belt.

[0070] <Electrophotographic image forming apparatus> The electrophotographic image forming apparatus comprises an electrophotographic belt according to one aspect of the present disclosure. Below, an example of an electrophotographic image forming apparatus using an electrophotographic belt according to one aspect of the present disclosure as an intermediate transfer belt will be described. The intermediate transfer belt is a component that secondarily transfers the toner image transferred from the photosensitive drum to the recording material.

[0071] As shown in Figure 1, this electrophotographic image forming apparatus has a so-called tandem configuration in which multiple color electrophotographic stations are arranged in the direction of rotation of the intermediate transfer belt. In the following description, the subscripts Y, M, C, and k are used for the yellow, magenta, cyan, and black color configurations, respectively, but the subscripts may be omitted for similar configurations.

[0072] In Figure 1, the photosensitive drums (photoreceptor, image carrier) 1Y, 1M, 1C, and 1k are surrounded by charging devices 2Y, 2M, 2C, and 2k, exposure devices 3Y, 3M, 3C, and 3k, developing devices 4Y, 4M, 4C, and 4k, and an intermediate transfer belt (intermediate transfer body) 6. The photosensitive drum 1 is driven to rotate at a predetermined peripheral speed (process speed) in the direction of arrow F (counterclockwise). The charging device 2 charges the peripheral surface of the photosensitive drum 1 to a predetermined polarity and potential (primary charging). The laser beam scanner, acting as the exposure device 3, outputs on / off modulated laser light corresponding to image information input from external devices such as an image scanner (not shown) or a computer, and scans and exposes the charged surface on the photosensitive drum 1. This scanning exposure forms an electrostatic latent image on the surface of the photosensitive drum 1 corresponding to the desired image information.

[0073] The developing devices 4Y, 4M, 4C, and 4k each contain toners for the respective color components: yellow (Y), magenta (M), cyan (C), and black (k). Based on the image information, the developing device 4 to be used is selected, and the developer (toner) is developed on one surface of the photosensitive drum, making the electrostatic latent image visible as a toner image. In this embodiment, an inversion development method is used in which toner is attached to the exposed area of ​​the electrostatic latent image and developed in this way. Furthermore, the electrophotographic image forming means is constructed by such a charging device, exposure device, and developing device.

[0074] Furthermore, the intermediate transfer belt 6 is composed of an electrophotographic belt having an endless shape. The intermediate transfer belt 6 is stretched by a plurality of rollers 20, 21, and 22 so that its outer surface is in contact with the surface of the photosensitive drum 1. In this embodiment, roller 20 is a tension roller that controls the tension of the intermediate transfer belt 6 to be constant, roller 22 is a drive roller for the intermediate transfer belt 6, and roller 21 is an opposing roller for secondary transfer. The intermediate transfer belt 6 rotates in the direction of arrow G by the drive of roller 22. Primary transfer rollers 5Y, 5M, 5C, and 5k are positioned at the primary transfer positions opposite the photosensitive drum 1 on either side of the intermediate transfer belt 6, respectively.

[0075] The unfixed toner images of each color formed on the photosensitive drum 1 are sequentially electrostatically transferred onto the intermediate transfer belt 6 by applying a primary transfer bias with the opposite polarity to the charge polarity of the toner to the primary transfer roller 5 using a constant voltage source or constant current source (not shown). A full-color image is then obtained by superimposing the four unfixed toner images onto the intermediate transfer belt 6. The intermediate transfer belt 6 rotates while carrying the toner images transferred from the photosensitive drum 1 in this manner. After each rotation of the photosensitive drum 1 following the primary transfer, the surface of the photosensitive drum 1 is cleaned of any remaining toner by the cleaning device 11, and the image formation process is repeated.

[0076] Furthermore, at the secondary transfer position of the intermediate transfer belt 6 facing the transport path of the recording material 7 as a transfer medium, a secondary transfer roller (transfer section) 9 is pressed against the toner image-carrying surface of the intermediate transfer belt 6. In addition, on the back side of the intermediate transfer belt 6 at the secondary transfer position, an opposing roller 21 is provided, which serves as the opposing electrode of the secondary transfer roller 9 and to which a bias is applied. When transferring the toner image on the intermediate transfer belt 6 to the recording material 7, a bias of the same polarity as the toner is applied to the opposing roller 21 by the transfer bias application means 28, for example, -1000 to -3000V, causing a current of -10 to -50μA to flow. The transfer voltage at this time is detected by the transfer voltage detection means 29. Furthermore, a cleaning device (belt cleaner) 12 is provided downstream of the secondary transfer position to remove any toner remaining on the intermediate transfer belt 6 after the secondary transfer.

[0077] The recording material 7 passes through the transport guide 8 and is transported in the direction of arrow H, and is introduced to the secondary transfer position. The recording material 7 introduced to the secondary transfer position is clamped and transported at the secondary transfer position, and at that time, a constant voltage bias (transfer bias) controlled to a predetermined value is applied to the opposing roller 21 of the secondary transfer roller 9 from the secondary transfer bias application means 28. By applying a transfer bias of the same polarity as the toner to the opposing roller 21, the four-color full-color image (toner image) superimposed on the intermediate transfer belt 6 at the transfer site is transferred to the recording material 7 all at once, forming a full-color unfixed toner image on the recording material. The recording material 7 that has received the toner image transfer is introduced to a fuser (not shown) and heated and fixed. [Examples]

[0078] Examples and comparative examples are shown below to illustrate the present disclosure in detail, but the present disclosure is not limited to these.

[0079] The materials used in the manufacture of the electrophotographic belts in the examples and comparative examples are shown below. (Polymer ionic conductive agent A) Polydiallyldimethylammonium bis(fluorosulfonyl)imide The structural formula is as follows. In the formula, n is 1300.

[0080] [ka]

[0081] (Polymer ionic conductive agent B) Polydiallyldimethylammonium bis(trifluoromethanesulfonyl)imide The structural formula is as follows. In the formula, n is 1300.

[0082] [ka]

[0083] (Polymer ionic conductive agent C) Polydiallyldimethylammonium chloride Manufactured by Sigma-Aldrich The structural formula is as follows. In the formula, n is 1300.

[0084] [ka]

[0085] (Monomer ion conductive agent) diallyldimethylammonium chloride Manufactured by Sigma-Aldrich The structural formula is as follows.

[0086] [ka]

[0087] The synthesis methods for polymer ionic conductive agent A and polymer ionic conductive agent B are described below. First, polymer ionic conductive agent C was diluted 10 times with pure water. Next, LiFSI (lithium bis(fluorosulfonyl)imide) and LiTFSI (lithium bis(trifluoromide) Tansulfonylimide was dissolved in pure water. Diluted polymer ionic conductive agent C A LiFSI aqueous solution or a LiTFSI aqueous solution was added dropwise to the liquid, and the mixture was stirred for 10 minutes. The resulting precipitate was collected by vacuum filtration and washed with pure water, and this process was repeated twice. The obtained white solids were dried under vacuum at 100°C for 24 hours to obtain polymer ionic conductive agent A and polymer ionic conductive agent B, respectively.

[0088] (Polyether ester amide) Product name: TPAE-12, manufactured by T&K TOKA Co., Ltd.

[0089] (Polyesteramide) Product name: TPAE-617, manufactured by T&K TOKA Co., Ltd.

[0090] (Polyetheramide) Product Name: Pebax MH 1657, manufactured by Arkema Co., Ltd.

[0091] (Polyether ester) Product name: Hytrel 6347E03, manufactured by Toray Celanese Co., Ltd.

[0092] (polyester) Product name: TN-8065S, manufactured by Teijin Limited

[0093] The measurement and evaluation methods used in each example are described below. (Evaluation 1) Confirmation of block copolymers containing segments with ester groups and segments with amide groups in the molecular chain. To determine whether ester and amide groups were present in the block copolymer isolated from the electrophotographic belt, we checked for the presence of peaks by infrared spectroscopy. Ten grams of the prepared electrophotographic belt were cut into 1 mm squares and immersed overnight in an organic solvent that dissolves block copolymers, such as ethanol. After removing the cut electrophotographic belt and evaporating the organic solvent, the infrared absorption spectrum of the remaining residue was measured. The apparatus and measurement conditions used were as follows. The definitions of the absorbance and peak intensity ratios for ester, amide, and ether groups are shown below. Device: Spotlight400 Universal ATR (manufactured by PerkinElmer) detector MIR-TGS Measurement range: 650-4000cm -1 Resolution 2cm -1 Total number of times: 8 ATR crystal diamond / ZnSe background air Horizontal axis unit: wavenumber Vertical axis unit: %A (absorbance) Absorbance A Ester group 1735 cm -1 Absorbance at the peak top in the vicinity of absorption (C=O stretching motion) Absorbance B, amide group, 1635 cm⁻¹ -1 Absorbance at the peak top in the vicinity of absorption (C=O stretching motion) Absorbance C Ether group 1100 cm -1 Absorbance of the peak top in the vicinity of absorption (CO stretching motion) Peak intensity ratio (ester group) = [Absorbance A / (Absorbance A + Absorbance B + Absorbance C)] Peak intensity ratio (amide group) = [Absorbance B / (Absorbance A + Absorbance B + Absorbance C)] Peak intensity ratio (ether group) = [Absorbance C / (Absorbance A + Absorbance B + Absorbance C)]

[0094] (Evaluation 2) Evaluation of surface resistivity The surface resistivity of the base layer of the electrophotographic belt was measured according to the method compliant with JIS-K6911. As the measuring device, a high-resistivity meter (product name: HighResta UP MCP-HT800, manufactured by Nitto Seikou Analytech Co., Ltd.) was used, with a probe (product name: UR-100, manufactured by Nitto Seikou Analytech Co., Ltd.) having a main electrode inner diameter of 50 mm, a guard / ring electrode inner diameter of 53.2 mm, and an outer diameter of 57.2 mm. Surface resistivity is calculated per unit area (1 cm²) of an electrophotographic belt. 2The surface resistivity is expressed as the value per square centimeter, in units of [Ω / □]. The base layer of the fabricated electrophotographic belt was left standing for 24 hours in an environmental test chamber controlled to a temperature of 23°C and a relative humidity of 50%. Subsequently, under the same conditions of 23°C and 50% relative humidity, a voltage of 250V was applied to the electrophotographic belt for 10 seconds, and the surface resistivity was measured at 20mm intervals in the circumferential direction of the base layer of the electrophotographic belt. The arithmetic mean of the obtained surface resistivity was used as an index of surface resistivity at normal temperature and humidity.

[0095] (Evaluation 3) Evaluation of conductivity unevenness In the above evaluation of surface resistivity, when the maximum value of the surface resistivity obtained was denoted as ρsmax and the minimum value as ρsmin, log(ρsmax / ρsmin) was used as an index of conductivity unevenness.

[0096] (Evaluation 4) Evaluation of bleed volume First, the base layer of the fabricated electrophotographic belt was cut into an 8.2 cm square, and its mass was measured. Then, the sample was sandwiched between a probe (product name: UR-100, manufactured by Nitto Seikou Analytech Co., Ltd.) and a metal plate (product name: RegiTable UFL, manufactured by Nitto Seikou Analytech Co., Ltd.) of a high-resistivity meter (product name: HighResta UP MCP-HT450), and energized at 1000 V for 60 minutes. After energizing, the sample surface was wiped with an organic solvent that dissolves ionic conductive agents such as acetone, and after the organic solvent was thoroughly dried, the sample mass was measured. Let A be the sample mass before applying electricity, and B be the sample mass after applying electricity. The amount of bleed was calculated as ((AB) / A × (percentage of ionic conductive agent added to the base layer (mass%)) × 100.

[0097] (Rating 5) Drum attack rating From the samples used to evaluate the amount of bleed, strips measuring 10 mm wide x 20 mm long were cut from the portion that the high-resistance meter probe had touched. The photosensitive drum from an electrophotographic laser printer (product name: LBP7700C, manufactured by Canon Inc.) was removed, and the strips of sample were wrapped around it. In this state, the drum was left in an environment of 60°C and 80% relative humidity for two weeks. Subsequently, the surface of the photosensitive drum was observed using a digital microscope (VHX-100F, manufactured by Keyence Corporation). Based on the observation results, drums that showed no cracks or stains were designated as A, and those that showed cracks or stains were designated as B.

[0098] (Rating 6) Image rating Image evaluation was ranked based on the degree of image unevenness that occurred when conductivity unevenness was present. An electrophotographic laser printer (product name: LBP7700C, manufactured by Canon Inc.) was used as the printer. The fabricated electrophotographic belt was installed as an intermediate transfer belt and left undisturbed for 24 hours in an environmental test chamber controlled at a temperature of 23°C and relative humidity of 50%. Xerox 4200 paper in letter size (manufactured by Xerox, 75g / m²) 2 A solid blue image was output on top of the above. The cyan and magenta developers contained in the print cartridge of the electrophotographic image forming apparatus were used to form the image. The obtained solid image was evaluated using the following procedure. A solid image was scanned using a scanner (product name: CanoScan 9000F, manufactured by Canon Inc.) at a scanning resolution of 600 dpi with image correction processing turned off. The image was then cropped to an area of ​​2550 x 2550 pixels (approximately 10.8 x 10.8 cm). The resulting image was visually observed at a display magnification of 200%, and whether or not image unevenness due to resistance variations was observed, and if so, to what extent, was evaluated according to the following criteria. Rank A: No image inconsistencies whatsoever. Rank B: Some minor inconsistencies are observed. Rank C: Irregularities are observed in approximately 20% of the observed image area. Rank D: Irregularities are observed across more than half of the observed images.

[0099] [Example 1] <Preparation of conductive resin compositions> Polymer ionic conductive agent A, polyether ester amide, and polyester were blended in the mass percentages listed in Table 1 and hot-melt kneaded. Each sample was placed in a twin-screw extruder (product name: TEX30α, manufactured by Japan Steel Works Ltd.) and kneaded at a temperature of 260°C for a kneading time of 4 minutes. The resulting conductive resin composition was pelletized.

[0100] <Preform creation> Next, the obtained conductive resin composition was dried at a temperature of 140°C for 6 hours. A preform was then fabricated from this pellet using an injection molding machine (product name: SE180EV-A, manufactured by Sumitomo Heavy Industries, Ltd.) with the cylinder set to a temperature of 280°C. The injection mold temperature at this time was 30°C. The obtained preform had a test tube shape with an outer diameter of 50 mm, an inner diameter of 46 mm, and a length of 150 mm.

[0101] <Biaxial stretching molding> The above preform was stretched in two axial directions, longitudinal and circumferential, using a biaxial stretching apparatus. First, as shown in Figure 3A, the preform 205 was placed in a heating device 301 equipped with a non-contact heater (not shown) for heating the preform 205, and the heater was used to heat the outer surface temperature of the preform to 150°C. Next, a blow mold 303, whose mold temperature was maintained at 30°C, was lowered in the direction of arrow 307, and the heated preform 205 was placed in the opening of the blow mold 303 (Figure 3B).

[0102] Next, as shown in Figure 3C, the stretching rod 309 was driven in the direction of arrow 311, and air heated to 23°C was introduced into the preform 205 through the opening, as indicated by arrow 313 in Figure 3C. In this way, the preform 205 was stretched in two axial directions and made to adhere closely to the inner wall of the blow mold. Next, the right mold 303-1 and the left mold 303-2 of the blow mold 303 were separated, and the bottle-shaped molded product (blow bottle) 317 was removed from the blow mold 303.

[0103] Next, the resulting blow-molded bottle 317 was placed inside a nickel cylindrical mold 401, which was manufactured by the electroforming method shown in Figure 4, and the outer mold 405 was attached. An air pressure of 0.1 MPa was applied inside the blow-molded bottle, and the pressure was adjusted so that no air leaked out, thereby ensuring that the outer surface of the blow-molded bottle 317 was in close contact with the inner surface of the cylindrical mold. Furthermore, the nickel cylindrical mold 401 was heated to 180°C using a heating heater 403 while rotating, and heated uniformly for a total of 60 seconds.

[0104] Subsequently, air at a temperature of 25°C was blown onto the nickel cylindrical mold and cooled to room temperature (25°C) for 1 minute. The air pressure applied inside the blow bottle 317 was then released, and a blow bottle 317 with improved dimensions due to annealing was obtained.

[0105] Next, as shown in Figure 3D, the mouth side and the opposite side of the blow-molded bottle 317 were cut to create an electrophotographic belt with a circumference of 630 mm, a width of 250 mm, and a thickness of 70 μm. The results of using this electrophotographic belt in Evaluation 1 are shown in Figure 6.

[0106] [Examples 2-6] An electrophotographic belt was prepared and evaluated in the same manner as in Example 1, except for the materials and proportions listed in Table 1 below. The evaluation results are shown in Table 2.

[0107] Example 2 involves increasing the amount of polymer ionic conductive agent. While the surface resistivity decreased due to the increased amount, the increased amount of polymer ionic conductive agent relative to the polyether ester amide made uniform dispersion more difficult. As a result, the conductivity unevenness became greater than in Example 1, and the image evaluation rank decreased.

[0108] Example 3 shows the case where the amount of polymer ionic conductive agent was reduced. Although the surface resistivity increased due to the reduction in amount, the conductivity unevenness decreased.

[0109] Example 4 involves changing the anion of the polymer ionic conductive agent to a TFSI anion. Due to its bulkier structure compared to the FSI anion, the ion movement slowed down, and although the surface resistivity was higher than in Example 1, the results were comparable to those of Example 1.

[0110] Example 5 shows the case where the anion of the polymer ionic conductive agent is changed to a chloride ion. Although not shown in Table 2, the surface resistivity became slightly more environmentally dependent on the environment because the chloride ion has higher hygroscopicity than the FSI anion. However, the surface resistivity under conditions of 15°C and 10% relative humidity was ρs LL The surface resistivity under conditions of 30°C and 80% relative humidity is ρs HH When this is done, log(ρs LL / ρs HH The environmental dependence of the surface resistivity was defined as follows.

[0111] Example 6 shows the case where the amount of polyether ester amide was reduced. This amount was sufficient to improve the dispersibility of the polyionic conductive agent, and results equivalent to those of Example 1 were obtained.

[0112] Example 7 uses a polyesteramide. Even without an ether group, it has good affinity with both the polyionic conductive agent and the polyester, allowing the polyionic conductive agent to be dispersed in the polyester, and yielding results equivalent to Example 1. In addition, in Example 7, infrared spectroscopy measurements showed that at 1100 cm⁻¹, -1 A peak was observed in the vicinity, which is a peak of CO stretching motion originating from the ester group.

[0113] [Comparative Examples 1-4] An electrophotographic belt was prepared and evaluated in the same manner as in Example 1, except for the materials and proportions listed in Table 1 below. The evaluation results are shown in Table 2. Comparative Example 1 involves using a monomer ion conductive agent instead of a polymer ion conductive agent. Because the ion conductive agent is a monomer, it is prone to bleeding, and cracks and stains were observed on the surface of the photosensitive drum during the drum attack test.

[0114] Comparative Example 2 is the case where polyether ester amide is not included. Because the polymer ionic conductive agent was not uniformly dispersed, the surface resistivity was high and the conductivity unevenness was large.

[0115] Comparative Example 3 involves using polyetheramide instead of polyetheresteramide. Because it lacks ester groups, it did not blend well with the polyester, making it impossible to uniformly disperse the polymer ionic conductive agent. As a result, the surface resistivity was high and the conductivity unevenness was large.

[0116] Comparative Example 4 is the case where a polyether ester was used instead of a polyether ester amide. Because it does not have an amide group, it did not blend well with the polymer ionic conductive agent, and the polymer ionic conductive agent could not be uniformly dispersed. As a result, the surface resistivity was high and the conductivity unevenness was large.

[0117] [Table 1]

[0118] [Table 2] In the table, for example, 1.3E+10 means 1.3 × 10 10 This indicates that...

[0119] This disclosure relates to the following configuration. (Composition 1) An electrophotographic belt having a base layer, The base layer is A polymer ionic conductive agent having a repeating structure containing cations and anions, A block copolymer containing a segment having an ester group and a segment having an amide group in its molecular chain, Polyester and An electrophotographic belt characterized by containing [a specific component]. (Configuration 2) The repeating structure containing the cation is a cationic polymer, The cation is a cation having an imidazolium structure, or a cation having a pyridinium structure. An electrophotographic belt according to configuration 1, comprising at least one selected from the group consisting of thion, a cation having a quaternary ammonium structure, and a cation having a quaternary phosphonium structure. (Configuration 3) The electrophotographic belt according to configuration 1 or 2, wherein the cation is a quaternary ammonium cation. (Composition 4) An electrophotographic belt according to any one of configurations 1 to 3, wherein the repeating structure containing the cation is polydiallyldimethylammonium. (Composition 5) The electrophotographic belt according to any one of configurations 1 to 4, wherein the block copolymer is a polyesteramide or a polyether esteramide. (Composition 6) The electrophotographic belt according to any one of configurations 1 to 5, wherein the anion is at least one ion selected from the group consisting of chloride ions and sulfonylimide ions containing fluorine. (Composition 7) An electrophotographic belt according to any one of configurations 1 to 6, wherein the anion is a fluorine-containing sulfonylimide ion. (Composition 8) An electrophotographic belt according to any one of configurations 1 to 7, wherein the content of the polymer ion conductive agent in the base layer is 0.09 to 2.0% by mass. (Composition 9) An electrophotographic belt according to any one of configurations 1 to 8, wherein the content of the block copolymer in the base layer is 2.0 to 20.0% by mass. (Composition 10) An electrophotographic image forming apparatus characterized by comprising an electrophotographic belt as described in any of configurations 1 to 9 as an intermediate transfer belt. [Explanation of Symbols]

[0120] 1 Photosensitive drum, 2 Charging device, 3 Exposure device, 4 Developing device, 5 Primary transfer roller, 6 Intermediate transfer belt, 7 recording material, 9 secondary transfer roller, 11 cleaning device (drum cleaner), 12 cleaning device (belt cleaner), 20 tension roller, 21 opposing roller, 22 drive roller, 28 transfer bias application means, 29 transfer high pressure detection means, 205 preform, 303 blow mold, 309 stretching rod, 317 blow bottle

Claims

1. An electrophotographic belt having a base layer, The base layer is A polymer ionic conductive agent having a repeating structure containing cations and anions, A block copolymer containing a segment having an ester group and a segment having an amide group in its molecular chain, Polyester and An electrophotographic belt characterized by containing [a specific component].

2. The repeating structure containing the cation is a cationic polymer, The electrophotographic belt according to claim 1, wherein the cation is at least one selected from the group consisting of a cation having an imidazolium structure, a cation having a pyridinium structure, a cation having a quaternary ammonium structure, and a cation having a quaternary phosphonium structure.

3. The electrophotographic belt according to claim 1, wherein the cation is a quaternary ammonium cation.

4. The electrophotographic belt according to claim 1, wherein the repeating structure containing the cation is polydiallyldimethylammonium.

5. The electrophotographic belt according to claim 1, wherein the block copolymer is a polyesteramide or a polyether esteramide.

6. The electrophotographic belt according to claim 1, wherein the anion is at least one ion selected from the group consisting of chloride ions and sulfonylimide ions containing fluorine.

7. The electrophotographic belt according to claim 1, wherein the anion is a fluorine-containing sulfonylime ion.

8. The electrophotographic belt according to claim 1, wherein the content of the polymer ion conductive agent in the base layer is 0.09 to 2.0% by mass.

9. The electrophotographic belt according to claim 1, wherein the content of the block copolymer in the base layer is 2.0 to 20.0% by mass.

10. An electrophotographic image forming apparatus characterized by comprising an electrophotographic belt as described in any one of claims 1 to 9 as an intermediate transfer belt.

Images