Electronic photography member, electronic photography image forming device, and method for manufacturing electronic photography member

Abstract

The electronic photography member uses a material which does not belong to PFAS and uses antimony-doped tin oxide particles, and can suppress adhesion with other members.SOLUTION: The electronic photography member includes a base layer and a front surface layer in direct contact with the base layer. The front surface layer includes a hetero-aggregate of first particles and second particles different from the first particles. The second particles include antimony-doped tin oxide particles having a specific particle size, the second surface layer has protrusions derived from the heteroaggregates on an outer surface side opposite to a side facing the base layer, an arithmetic average height (Sa) of the outer surface side is 0.10 to 0.70 μ m, the second surface layer includes an ion conducting agent containing a specific anion and an alkali metal cation, and a (meth) acrylic resin, and a content of the ion conducting agent in the second surface layer is in a specific range. 100nm.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD This disclosure relates to electrophotographic members, electrophotographic image forming apparatus, and methods for manufacturing electrophotographic members. [Background technology]

[0002] In an electrophotographic image forming apparatus, an electrophotographic belt is used as a transport / transfer belt that transports a transfer material and as an electrophotographic member that temporarily transfers and holds a toner image. The electrophotographic belt comes into contact with and slides against other members in the electrophotographic image forming apparatus, and if the surface of the electrophotographic belt is excessively smooth, it may come into close contact with other members.

[0003] For example, if a photosensitive drum or a cleaning blade comes into close contact with the surface of the electrophotographic belt, the stable rotation of the electrophotographic belt may be hindered. A decrease in the stability of the rotation of the electrophotographic belt may result in, for example, an unstable movement speed of the electrophotographic belt, which may cause misalignment when transferring toner images of each color to paper. Therefore, in order to prevent other members from coming into close contact with the outer surface of the electrophotographic belt, the surface of the electrophotographic belt has conventionally been roughened.

[0004] In Patent Document 1, a method for roughening the surface of an electrophotographic belt involves hetero-aggregation of inorganic oxide particles having a particle size of 10 to 30 nm and conductive metal oxide particles having a particle size of 5 to 40 nm in the presence of alkali metal ions. Convex portions resulting from the hetero-aggregation are then formed. Specifically, the base layer of the electrophotographic belt contains an alkali metal salt of perfluoroalkylsulfonic acid or an alkali metal salt of perfluoroalkylsulfonimide. A curable composition containing the inorganic oxide particles, the conductive metal oxide particles, an acrylic monomer, and a solvent is then applied to the base layer. During the process of drying the solvent in the curable composition, the alkali metal ions in the base layer migrate to the surface layer, resulting in hetero-aggregation. The invention of Patent Document 1 uses particles with small particle diameters as the particles used for roughening, thereby preventing the formation of specific large protrusions, and roughens the surface of the surface layer by forming hetero-aggregates of small particle diameter particles. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-146024 Summary of the Invention [Problem to be solved by the invention]

[0006] At least one aspect of the present disclosure is directed to providing an electrophotographic member that uses a material that does not belong to PFAS and that uses antimony-doped tin oxide particles, which can suppress adhesion with other members. At least one aspect of the present disclosure is directed to providing a method for manufacturing an electrophotographic member that uses a material that does not belong to PFAS and that uses antimony-doped tin oxide particles, which can suppress adhesion with other members. Furthermore, at least one aspect of the present disclosure is directed to providing an electrophotographic image forming apparatus that can stably form high-quality electrophotographic images. [Means for solving the problem]

[0007] According to at least one aspect of the present disclosure, a substrate; and a surface layer directly adjacent to the base layer, the surface layer comprises a hetero-aggregate of first particles and second particles different from the first particles; The first particles include: The inorganic oxide particles have a number average major axis of 30 to 100 nm, The second particles are antimony-doped tin oxide particles; and the number average particle size of the primary particles of the second particles is 5 to 40 nm; the surface layer has convex portions derived from the hetero-aggregate on an outer surface opposite to the surface facing the base layer, The arithmetic mean height (Sa) of the outer surface is 0.10 to 0.70 μm, The surface layer is an ion conductive agent containing at least one anion selected from the group consisting of anions represented by the following formulas (A1) to (A4) and an alkali metal cation; (meth)acrylic resin, the content of the ion conductive agent relative to the (meth)acrylic resin in the surface layer is 1.0 to 5.0 mmol / kg; An electrophotographic member is provided.

[0008] Also, in accordance with at least one aspect of the present disclosure, there is provided a method for manufacturing an electrophotographic member having a base layer and a surface layer in direct contact with the base layer, the method comprising: The manufacturing method comprises: providing a base layer; A step of preparing a curable composition containing the following components (a) to (e): forming a coating of the curable composition on one surface of the base layer and drying the coating; and curing the dried coating; A method for manufacturing an electrophotographic member having the following is provided. (a) first particles that are inorganic oxide particles having a number-average major axis size of 30 to 100 nm; (b) second particles different from the first particles, having a number-average particle size of primary particles of 5 to 40 nm, the second particles including antimony-doped tin oxide particles; (c) (meth)acrylic monomers; (d) at least one solvent selected from the group consisting of 2-butanone and 4-methyl-2-pentanone; (e) a salt containing at least one anion selected from the group consisting of anions represented by the following formulae (A1) to (A4) and an alkali metal cation;

[0009] According to at least one aspect of the present disclosure, there is also provided an electrophotographic image forming apparatus including the electrophotographic member as an intermediate transfer belt. [ka] R1 to R4 are each independently a hydrogen atom, a hydrocarbon group having 1 to 18 carbon atoms, or an alkoxy group having 1 to 18 carbon atoms. [Effects of the Invention]

[0010] According to at least one embodiment of the present disclosure, an electrophotographic member can be obtained that uses a material that does not belong to PFAS and that uses antimony-doped tin oxide particles, and that can suppress adhesion with other members. Furthermore, according to at least one embodiment of the present disclosure, a method for producing an electrophotographic member can be obtained that uses a material that does not belong to PFAS and that uses antimony-doped tin oxide particles, and that can suppress adhesion with other members. Furthermore, according to at least one embodiment of the present disclosure, an electrophotographic image forming apparatus can be obtained that can stably form high-quality electrophotographic images. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic cross-sectional view of an electrophotographic belt. [Figure 2] FIG. 2 is an explanatory diagram of an electrophotographic image forming apparatus. [Figure 3] FIG. 3 is a schematic diagram of a jig for evaluating the adhesion between an electrophotographic belt and other members. DETAILED DESCRIPTION OF THE INVENTION

[0012] Unless otherwise specified, 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 and upper limits, which are the endpoints. When a numerical range is described in stages, the upper and lower limits of each numerical range can be arbitrarily combined. In addition, in the present disclosure, In the above, for example, a description such as "at least one selected from the group consisting of XX, YY, and ZZ" means any 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. When XX is a group, multiple XXs may be selected, and the same applies to YY and ZZ.

[0013] In recent years, restrictions on the use of perfluoroalkyl and polyfluoroalkyl substances (hereinafter also referred to as "PFAS"), which are considered to have high environmental persistence and bioaccumulation, have been under consideration. Patent Document 1 uses an anion having a C—F bond in the molecule, and it is possible that the salt described in Patent Document 1 will no longer be usable due to future restrictions. Therefore, the present inventors investigated the formation of convex portions on the surface of the surface layer even when the base layer contains a salt of an anion that does not have a C—F bond in the molecule and does not belong to PFAS, and an alkali metal cation.

[0014] The present inventors formed a surface layer by applying the coating material for forming a surface layer according to Patent Document 1 to a base layer containing a salt of an anion not belonging to PFAS (hereinafter also referred to as a "non-PFAS anion") and an alkali metal cation. However, hetero-aggregation of the particles described in Patent Document 1, i.e., inorganic oxide particles with an average primary particle diameter of 10 to 30 nm and conductive metal oxide particles with an average primary particle diameter of 5 to 40 nm, was difficult to occur, making it difficult to form a rough surface on the outer surface of the surface layer with an arithmetic mean height Sa of 0.10 to 0.70 μm. In addition, the inventors recognized the problem that when relatively inexpensive antimony-doped tin oxide particles are used as a conductive agent, it is difficult to form a rough surface on the outer surface of the surface layer compared to other conductive agents (e.g., zinc antimonate), and this can lead to adhesion to other components.

[0015] The reason why heteroaggregation is less likely to occur when salts of non-PFAS anions and alkali metal cations are included in the base layer is thought to be as follows: Non-PFAS anions have a localized negative charge, which means they bind strongly to alkali metal cations, while salts of non-PFAS anions and alkali metal cations have a low degree of ionic dissociation. Therefore, it is presumed that alkali metal cations do not migrate sufficiently from the base layer to the surface layer, preventing the formation of heteroaggregates.

[0016] Therefore, the present inventors conducted extensive research aimed at roughening the outer surface of the surface layer using heteroaggregates, assuming the use of a salt of a non-PFAS anion and an alkali metal cation and antimony-doped tin oxide particles as a conductive agent. Based on the above considerations, during the course of this research, the present inventors considered incorporating a salt of a non-PFAS anion and an alkali metal cation into the surface layer rather than into the base layer.

[0017] As a result, the inventors discovered that the following configuration allows stable formation of convex portions on the outer surface of the surface layer by hetero-aggregates of first particles and second particles. Specifically, the surface layer contains inorganic oxide particles as the first particles having a number-average major axis diameter of 30 to 100 nm, and antimony-doped tin oxide particles as the second particles having a number-average particle diameter of 5 to 40 nm. The surface layer further contains an ionic conductive agent containing at least one anion selected from the group consisting of anions represented by the following formulas (A1) to (A4) and an alkali metal cation, and a (meth)acrylic resin. The content of the ionic conductive agent relative to the (meth)acrylic resin in the surface layer is 1.0 to 5.0 mmol / kg. As a result, a rough surface with an arithmetic mean height (Sa) of 0.10 to 0.70 μm can be formed on the outer surface of the surface layer.

[0018] The inventors believe that the reason why convex portions made of heteroaggregates could be stably formed even when a salt composed of a non-PFAS anion and an alkali metal cation and antimony-doped tin oxide particles were used as the conductive agent is as follows.

[0019] As mentioned above, antimony-doped tin oxide particles are difficult to form a rough surface. However, the present inventors have found that it is effective to incorporate a specific content of an ionic conductive agent containing a specific anion and an alkali metal cation into the surface layer. Specifically, the content of the ionic conductive agent relative to the (meth)acrylic resin in the surface layer is 1.0 to 5.0 mmol / kg. It is believed that a content of the ionic conductive agent of 1.0 mmol / kg or more provides a cation concentration sufficient to cause hetero-coagulation even when antimony-doped tin oxide particles are used.

[0020] Furthermore, as mentioned above, when a salt composed of a non-PFAS anion and an alkali metal cation is contained in the base layer, migration of the cations to the surface layer is insufficient, making it difficult to form convex portions due to heteroaggregates. The inventors have found that, to address this issue, it is effective to contain an ionic conductive agent containing a specific anion and an alkali metal cation in the surface layer at a concentration of 1.0 to 5.0 mmol / kg relative to the (meth)acrylic resin. It is believed that a content of the ionic conductive agent of 1.0 mmol / kg or more provides a cation concentration sufficient for heteroaggregation.

[0021] <Ionic conductive agent> The ionic conductive agent (salt) contains an alkali metal cation and at least one anion selected from the group consisting of anions represented by the following formulas (A1) to (A4).

[0022] Anions The anion is at least one kind of anion selected from the group consisting of anions represented by the following formulae (A1) to (A4). [ka]

[0023] R1 to R4 are each independently a hydrogen atom, a hydrocarbon group having 1 to 18 carbon atoms, or an alkoxy group having 1 to 18 carbon atoms.

[0024] ·Cation The cation is not particularly limited as long as it is an alkali metal cation, and preferably includes at least one selected from the group consisting of a lithium ion, a sodium ion, and a potassium ion.

[0025] <First particle> The first particles are inorganic oxide particles having a number average major axis size of 30 to 100 nm.

[0026] <Second particle> The second particles are different from the first particles. The second particles include antimony-doped tin oxide particles, and the number average particle size of the primary particles of the second particles is 5 to 40 nm.

[0027] Hereinafter, an embodiment of an electrophotographic belt will be described in detail as an example of an embodiment of an electrophotographic member. However, the present disclosure may also be applied to other electrophotographic members such as an electrophotographic roller, and is not limited to the following embodiment.

[0028] Roughening the outer surface of the surface layer to an arithmetic mean height (Sa) of 0.10 to 0.70 μm can be achieved, for example, by the following method. A coating film of a surface layer-forming composition containing an ion conductive agent (salt) composed of an alkali metal cation, the first particles, and the second particles is formed on a base layer. Alternatively, a coating film of a surface layer-forming composition containing the first particles and the second particles may be formed on a base layer that has been previously coated with an ion conductive agent (salt) composed of the non-PFAS anion and an alkali metal cation.

[0029] During the drying process of the coating film formed as described above, the cation concentration in the coating film increases, causing the first particles and the second particles to aggregate (hetero-aggregate) in the coating film. During the drying process of the coating film, the cation concentration in the coating film increases, and the charges of the first particles and the second particles in the coating film become opposite in polarity, forming hetero-aggregates. This allows convex portions derived from the hetero-aggregates to be formed on the surface of the surface layer, achieving a roughness Sa within the above range.

[0030] Here, the convex portions derived from hetero-aggregates include, for example, at least one selected from the group consisting of convex portions formed by exposing at least a portion of the hetero-aggregates on the surface of the surface layer, and convex portions formed by coating the surface of the hetero-aggregates with the matrix resin in the surface layer.

[0031] By roughening the surface to an arithmetic mean height (Sa) in the range of 0.10 to 0.70 μm, adhesion to other members can be suppressed. The arithmetic mean height (Sa) of the surface of the surface layer is preferably 0.10 to 0.60 μm, or 0.20 to 0.60 μm. The arithmetic mean height (Sa) of the surface of the surface layer can be adjusted, for example, by adjusting at least one element selected from the group consisting of the particle size of the first particles, the particle size of the second particles, the amount of the first particles, the amount of the second particles, and the amount of the ionic conductive agent.

[0032] An electrophotographic belt will be described as an example of an electrophotographic member according to the present disclosure. A cross-sectional conceptual diagram of an electrophotographic belt is shown in Figure 1. The electrophotographic belt has an electrophotographic seamless belt base layer a1 and a surface layer a2 that is in direct contact with the base layer. The thickness of the base layer is not particularly limited, but is preferably 10 μm to 500 μm, particularly 30 μm to 150 μm, and further preferably 50 μm to 100 μm.The thickness of the surface layer is not particularly limited, but is preferably 0.05 μm to 20 μm, particularly 0.1 μm to 5 μm, and further preferably 1 μm to 3 μm.

[0033] <<Curable composition>> The surface layer may be, for example, a cured product of the following curable composition. <Constituents of the curable composition> The components of the curable composition for forming the surface layer are listed below: The curable composition contains, for example, components (a) to (d), and preferably contains components (a) to (e).

[0034] (a) Component (first particle) The first particles are inorganic oxide particles having a number-average major axis size of 30 to 100 nm. The particles having a number-average major axis size of 30 to 100 nm are, for example, chain-like or spherical particles, and are hollow or solid particles. The chain-like particles are aggregates of particles in which multiple particles are connected in a linear or curved manner. The shape of each particle forming the chain-like particles may be clearly observed, or the particles may be fused together and lose their shape.

[0035] The first particles are preferably chain-like particles. In the interaction with the second particles described later, spherical particles are in point contact, whereas chain-like particles are in multi-point contact. Therefore, the interaction between the second particles and the first particles is likely to occur, and convex portions resulting from hetero-aggregates are formed on the surface of the surface layer. Easy to achieve. Chain particles are randomly shaped particles with a short diameter and a long diameter. The short diameter of chain particles corresponds to the average particle size of the primary particles. The long diameter of chain particles corresponds to the Feret diameter of the secondary particles.

[0036] The number-average major axis of the first particles is 30 to 100 nm, preferably 40 to 80 nm, and more preferably 50 to 75 nm. The number-average ratio of the major axis to the minor axis of the first particles (major axis / minor axis) is preferably 3 to 8, more preferably 4 to 7, and even more preferably 4 to 6. By setting the values ​​of the major axis and the major axis / minor axis of the first particles within the above ranges, the dispersion state in the curable composition (liquid) can be stabilized, and even when the curable composition is stored for a long period of time and then used to form a surface layer, a surface layer having sufficient hetero-aggregates on the outer surface can be stably formed.

[0037] Furthermore, the first particles are preferably hollow particles. Hollow particles have a smaller specific gravity than solid particles, which contributes to further extending the life of the curable composition. In other words, the curable composition according to the present disclosure can be used to more stably produce electrophotographic belts.

[0038] The inorganic oxide particles are preferably silica particles from the viewpoints of being stably dispersed in an organic solvent and being negatively charged.The first particles are preferably chain-like silica particles. The first particles can be used without surface treatment, but the first particles may be surface treated with a silane coupling agent or the like.

[0039] Here, the first particles may be, for example, chain silica particles "IPA-ST-UP" (trade name; Nissan Chemical Industries, Ltd.), hollow silica particles "Surulia 4110" (trade name; JGC Catalysts and Chemicals Co., Ltd.), colloidal silica "IPA-ST-L" (trade name; Nissan Chemical Industries, Ltd.), or the like.

[0040] (b) Component (second particle) The second particles include antimony-doped tin oxide particles having a number-average particle size of primary particles of 5 to 40 nm. When an electrophotographic member is used as, for example, an intermediate transfer belt, the surface layer is required to be semiconductive, and therefore, relatively inexpensive conductive antimony-doped tin oxide particles are used as the second particles.

[0041] The number-average particle size of the primary particles of the second particles is 5 to 40 nm, preferably 5 to 25 nm, and more preferably 15 to 25 nm. By setting the number-average particle size of the primary particles of the second particles within the above range, the formation of singular points (lumps) on the outer surface of the surface layer can be prevented. Furthermore, the dispersion state in the curable composition (liquid) can be stabilized, and even when the curable composition is used to form a surface layer after long-term storage, a surface layer having an outer surface Sa of 0.10 to 0.70 μm can be stably formed. The second particles may be surface-treated to enhance dispersion stability in organic solvents.

[0042] The second particles may be known particles, such as commercially available products such as SN-100P (product name) manufactured by Ishihara Sangyo Kaisha, Ltd. Alternatively, a slurry may be prepared from SN-100P and then used.

[0043] The antimony-doped tin oxide particles may be surface-treated. The antimony-doped tin oxide particles are preferably treated with a silane coupling agent. The second particles are a mixture of antimony-doped tin oxide particles treated with a silane coupling agent and tin oxide particles treated with a silane coupling agent. The content of the antimony-doped tin oxide particles treated with a silane coupling agent is preferably 3 to 20 parts by mass, and more preferably 5 to 20 parts by mass, per 100 parts by mass of the (meth)acrylic resin. When the content of the antimony-doped tin oxide particles is within the above range, gloss unevenness (unevenness of projections and depressions with a period smaller than Sa) tends to be small, and the effect of suppressing adhesion to other members tends to be obtained.

[0044] (c) Component Matrix resin monomers; The surface layer contains a matrix resin. That is, the surface layer preferably contains heteroaggregates of the first particles and the second particles in the matrix resin. The surface layer contains, for example, a (meth)acrylic resin as the matrix resin. The surface layer may contain other matrix resins in addition to the (meth)acrylic resin.

[0045] The matrix resin is not particularly limited, and known resins used in the surface layer of electrophotographic members such as intermediate transfer belts can be used. The matrix resin contains at least a (meth)acrylic resin, which provides excellent scratch resistance to the outer surface of the surface layer. In this case, the curable composition used to form the surface layer preferably contains a monomer that forms the matrix resin, such as a (meth)acrylic monomer.

[0046] The (meth)acrylic monomer is not particularly limited, but polyfunctional (meth)acrylic monomers are preferred from the viewpoint of abrasion resistance and hardness. Suitable examples include pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, trimethylolpropane tri(meth)acrylate, EO-modified trimethylolpropane tri(meth)acrylate, PO-modified trimethylolpropane tri(meth)acrylate, dipentaerythritol penta- and hexa(meth)acrylate, and isocyanuric acid EO-modified di- and tri(meth)acrylate. It is particularly preferred that the acrylic monomer contains dipentaerythritol penta- and hexa(meth)acrylate. It is also possible to use multiple acrylic monomers to adjust cure shrinkage and viscosity. Alternatively, commercially available products such as Aronix M-305 (trade name) manufactured by Toagosei Co., Ltd. may be used.

[0047] The content of the matrix resin in the surface layer is preferably 60.0 to 85.0 mass %, and more preferably 65.0 to 80.0 mass %, based on the mass of the surface layer.

[0048] (d) Ingredients solvent; From the viewpoint of stably dispersing or dissolving the above-described components (a), (b), and (c) as well as the below-described component (e), the curable composition preferably contains a solvent. The solvent preferably contains at least one selected from the group consisting of 2-butanone and 4-methyl-2-pentanone. In order to adjust the evaporation rate and viscosity, it is also possible to add a plurality of solvents other than those mentioned above. Specific examples include the following:

[0049] Alcohols such as methanol, ethanol, isopropanol, butanol, and octanol; ketones such as acetone and cyclohexanone; Esters such as ethyl acetate, butyl acetate, ethyl lactate, γ-butyrolactone, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate; ethers such as ethylene glycol monomethyl ether and diethylene glycol monobutyl ether, aromatic hydrocarbons such as benzene, toluene, and xylene; Amides such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone.

[0050] Of these, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, toluene, xylene, and the like are preferred.

[0051] The curable composition for forming the surface layer, which contains the above components (a) and (b), and preferably contains at least the components (a) to (d), preferably contains the following component (e):

[0052] Component (e) (ionic conductive agent) When a coating material for forming a surface layer contains particles with a relatively large average primary particle diameter capable of forming a roughened surface with an Sa of 0.10 to 0.70 μm on the outer surface of the surface layer, it is difficult to avoid the formation of specific protrusions due to particle aggregation in the coating material. In contrast, in the present disclosure, the first particles, which are too small to achieve an Sa within the above range, and the second particles are hetero-aggregated by the action of an ionic conductive agent. By forming convex portions on the surface of the surface layer using this hetero-aggregate, it is possible to prevent the formation of specific protrusions on the outer surface of the surface layer while achieving stable surface roughening.

[0053] The hetero-aggregation of the first particles and the second particles can be achieved, for example, by the action of component (e). For example, a coating film of the curable composition containing component (e) is formed on a base layer, and the coating film is dried. During the drying process of the coating film, as the solvent in the coating film evaporates, the cation concentration in the coating film increases, and the charges of the first particles and the second particles in the coating film become opposite in polarity, resulting in the formation of hetero-aggregates.

[0054] As described above, component (e) can be incorporated into the curable composition to form hetero-aggregates in the coating film, but this is not limitative. Component (e) may be applied to the base layer in advance, or component (e) may be incorporated into both the base layer and the curable composition.

[0055] Component (e) contains an alkali metal cation and at least one anion selected from the group consisting of anions represented by formulas (A1) to (A4), which are as described above.

[0056] The anion may be a non-PFAS anion that does not contain a C—F bond, and specifically, anions represented by formulae (A1) to (A4) can be used. The anions represented by (A1) to (A4) will be explained in detail. The anion shown in formula (A1) is a fluorosulfonylimide anion that does not have a C—F bond in the molecule and does not belong to PFAS.

[0057] In (A2) to (A4), R1 to R4 each independently represent a hydrogen atom, a hydrocarbon group having 1 to 18 carbon atoms, or an alkoxy group having 1 to 18 carbon atoms. Examples of the hydrocarbon group include a linear or branched saturated hydrocarbon group, a linear or branched unsaturated hydrocarbon group, a substituted or unsubstituted saturated alicyclic hydrocarbon group, a substituted or unsubstituted unsaturated alicyclic hydrocarbon group, and a substituted or unsubstituted aromatic hydrocarbon group.

[0058] Preferred examples of R1 include a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms (more preferably 1 to 3 carbon atoms), or a substituted or unsubstituted aryl group (specifically Examples of the phenyl group include an unsubstituted phenyl group and a phenyl group substituted with an alkyl group having 1 to 3 carbon atoms (more preferably 1 or 2 carbon atoms).

[0059] Preferred examples of R2 include alkyl groups having 3 to 15 carbon atoms (more preferably 6 to 12 carbon atoms). Preferred examples of R3 and R4 include each independently a linear or branched alkyl group having 3 to 15 carbon atoms (more preferably 6 to 12 carbon atoms).

[0060] Specific examples of the anion represented by formula (A2) are listed below. Sulfonate ion, methanesulfonate ion, ethanesulfonate ion, 1-butanesulfonate ion, p-toluenesulfonate ion (tosylate ion), 1-octanesulfonate ion, 1-decanesulfonate ion, 1-tetradecanesulfonate ion, 1-octadecanesulfonate ion, hydrogensulfate ion, methylsulfate ion, ethylsulfate ion, 1-butylsulfate ion, 1-octylsulfate ion, 1-decylsulfate ion, 1-tetradecylsulfate ion, and 1-octadecylsulfate ion. More preferably, methanesulfonate ion, ethanesulfonate ion, p-toluenesulfonate ion, and hydrogensulfate ion.

[0061] Specific examples of the anion represented by formula (A3) are listed below. Methanoate ion, ethanoate ion, butanoate ion, hexanoate ion, benzoate ion, octanoate ion, decanoate ion, dodecanoate ion, tetradecanoate ion, hexadecanoate ion, octadecanoate ion, methyl carbonate ion, ethyl carbonate ion, butyl carbonate ion, hexyl carbonate ion, octyl carbonate ion, decyl carbonate ion, tetradecyl carbonate ion, and octadecyl carbonate ion. Decanoate ion is more preferred.

[0062] Specific examples of the anion represented by formula (A4) are listed below. Phosphinate ion, dimethylphosphinate ion, ethylmethylphosphinate ion, diethylphosphinate ion, dibutylphosphinate ion, bis(2,4,4-trimethylpentyl)phosphinate ion, dioctylphosphinate ion, ditetradecylphosphinate ion, dioctadecylphosphinate ion, dimethyl phosphate ion, diethyl phosphate ion, dibutyl phosphate ion, more preferably at least one selected from the group consisting of diethylphosphinate ion and bis(2,4,4-trimethylpentyl)phosphinate ion, and even more preferably bis(2,4,4-trimethylpentyl)phosphinate ion.

[0063] Particularly preferred examples of the anion component include the anions listed in Table 2 below. Furthermore, examples of preferred combinations of cations and anions for component (e) include the combinations shown in Table 2 below.

[0064] The content of the ionic conductive agent, which is composed of such a specific anion and an alkali metal cation, in the surface layer is 1.0 to 5.0 mmol / kg relative to the (meth)acrylic resin. If the amount of the ionic conductive agent is less than 1.0 mmol / kg, it becomes difficult to form convex portions by heteroaggregates of the (a) component and the (b) component. If the amount of the ionic conductive agent is more than 5.0 mmol / kg, it becomes difficult to stably form convex portions. From the viewpoint of stably forming the convex portions, the amount of the ion conductive agent relative to the (meth)acrylic resin is preferably 1.8 to 5.0 mmol / kg, and more preferably 2.2 to 5.0 mmol / kg.

[0065] Radical polymerization initiators; Examples of the radical polymerization initiator include compounds that thermally generate active radical species ( Examples of the initiator include compounds that generate active radical species upon irradiation with radiation (light) (thermal polymerization initiators), and compounds that generate active radical species upon irradiation with radiation (light) (radiation (photo)polymerization initiators). There are no particular limitations on the radiation (photo)polymerization initiator as long as it is decomposed by light irradiation to generate radicals and initiate polymerization, and examples thereof include the following:

[0066] Acetophenone, acetophenone benzyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-1,2-diphenylethan-1-one, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-diaminobenzophenone, benzoin propyl ether, benzoin ethyl ether, benzil dimethyl ketal, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxane Examples of suitable thioxanthone include thioxanthone, diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, and oligo(2-hydroxy-2-methyl-1-(4-(1-methylvinyl)phenyl)propanone).

[0067] The amount of radical polymerization initiator blended is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, per 100 parts by mass of component (c). If the blending amount is 0.01 part by mass or more, the cured product will not have sufficient hardness, while if the blending amount is 10 parts by mass or less, the cured product will not be sufficiently cured to the inside (lower layer).

[0068] ·others If necessary, other components may be added to the curable composition within a range that does not impair the effects of the present disclosure, such as a polymerization inhibitor, a polymerization initiator aid, a leveling agent, a wettability improver, a surfactant, a plasticizer, an ultraviolet absorber, an antioxidant, an antistatic agent, an inorganic filler, or a pigment.

[0069] <Method for producing curable composition> The method for producing the curable composition is not particularly limited. However, since the curable composition contains particulate substances (a) and (b) and often highly viscous component (c), it is preferably produced as follows: A slurry in which component (a) is dispersed in a solvent, a slurry in which component (b) is dispersed in a solvent, and a solution in which component (c) is dissolved in a solvent are prepared in advance. These, along with components (d), (e), a polymerization initiator, and other components are then placed in a container equipped with a stirrer in the formulation described below and stirred for, for example, 30 minutes at room temperature to obtain the curable composition. The concentration of the slurry or solution may be set within a range that allows easy stirring. The total amount of solvent is preferably, for example, 200 to 2,000 parts by mass or 500 to 1,200 parts by mass per 100 parts by mass of the total of components (a), (b), and (c).

[0070] <Curing method> It is preferable to obtain a surface layer by curing a curable composition. The curable composition can be cured by heat or radiation (light, electron beam, etc.). There are no particular limitations on the actinic radiation as long as it can provide energy capable of generating polymerization initiation species, and it broadly includes α-rays, γ-rays, X-rays, ultraviolet rays (UV), visible light, electron beams, etc. Among these, ultraviolet rays and electron beams are preferred from the viewpoint of curing sensitivity and ease of equipment availability, and ultraviolet rays are particularly preferred. stomach.

[0071] <<<Electrophotographic Materials>>> The electrophotographic member will now be described. The electrophotographic member is composed of multiple layers, and the surface layer can be formed using the above-mentioned curable composition. The electrophotographic member may be, for example, in the form of a roller or belt, and is preferably in the form of a belt. In the following, an embodiment of an electrophotographic belt having two layers, consisting of a base layer and a surface layer, will be described, but other layers, such as an inner layer, may also be present.

[0072] (f) Ingredients resin; The base layer can be a molded product of a resin-containing resin composition for forming the base layer. The resin used to form the base layer is not particularly limited, and various resins can be used. Specific examples include polyimide (PI), polyamide-imide (PAI), polypropylene (PP), polyethylene (PE), polyamide (PA), polylactic acid (PLLA), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polycarbonate (PC), and fluororesins (such as PVdF), as well as blends thereof. In particular, the resin is preferably at least one selected from the group consisting of polyethylene terephthalate (PET) and polyethylene naphthalate (PEN).

[0073] The resin composition may contain other components as needed, such as ionic conductive agents (e.g., polymeric ionic conductive agents, surfactants), conductive polymers, antioxidants (e.g., hindered phenols, phosphorus, and sulfur-based), ultraviolet absorbers, organic pigments, inorganic pigments, pH adjusters, crosslinking agents, compatibilizers, mold release agents (e.g., silicone-based and fluorine-based), crosslinking agents, coupling agents, lubricants, insulating fillers (e.g., zinc oxide, barium sulfate, calcium sulfate, barium titanate, potassium titanate, strontium titanate, titanium oxide, magnesium oxide, magnesium hydroxide, aluminum hydroxide, talc, mica, clay, kaolin, hydrotalcite, silica, alumina, ferrite, calcium carbonate, barium carbonate, nickel carbonate, glass powder, quartz powder, glass fiber, alumina fiber, potassium titanate fiber, and fine particles of thermosetting resin), conductive fillers (e.g., carbon black, carbon fiber, conductive titanium oxide, conductive tin oxide, and conductive mica), and ionic liquids. These may be used alone or in combination of two or more.

[0074] <Base layer manufacturing method> The method for producing the base layer is not particularly limited, and a molding method suitable for various resins may be used. The base layer can be obtained by heating and molding a resin composition containing component (f) as necessary. Examples of molding methods include extrusion molding, inflation molding, blow molding, and centrifugal molding. After component (f) is melt-kneaded to obtain a resin composition, the resin composition can be extrusion-molded to obtain a cylindrical film-shaped base layer. A known device such as a twin-screw kneading extruder can be used for melt-kneading. In the examples and comparative examples described below, the base layer was obtained by extrusion molding.

[0075] <<Surface layer formation method>> The surface layer has convex portions derived from the hetero-aggregate on the outer surface opposite to the surface facing the base layer. The method for producing the surface layer is not particularly limited, but as described above, it is preferable to have a step of applying a curable composition to the base layer and curing it to obtain the surface layer. The method for manufacturing an electrophotographic belt more preferably comprises: providing a base layer; A step of preparing a curable composition containing the following components (a) to (e): forming a coating of the curable composition on one surface of the base layer and drying the coating; and curing the dried coating; It has. (a) first particles that are inorganic oxide particles having a number-average major axis size of 30 to 100 nm; (b) second particles different from the first particles, having a number-average particle size of primary particles of 5 to 40 nm, the second particles including antimony-doped tin oxide particles; (c) (meth)acrylic monomers; (d) at least one solvent selected from the group consisting of 2-butanone and 4-methyl-2-pentanone; (e) a salt containing an alkali metal cation and at least one anion selected from the group consisting of the anions represented by the above formulas (A1) to (A4); As described above, this production method can form hetero-aggregates of the first particles and the second particles in the coating film due to an increase in the cation concentration during curing of the coating film, thereby forming convex portions.

[0076] The coating method is not particularly limited, and any known method can be used. In the examples and comparative examples described below, dip coating was used. For example, the base layer is fitted onto the outer periphery of a cylindrical mold, the edges are sealed, and the mold is then immersed in a container filled with the curable composition, and the base layer is pulled up so that the relative speed between the liquid surface of the curable composition and the base layer is constant, thereby forming a coating film of the curable composition on the surface of the base layer. The pulling speed (the relative speed between the liquid surface of the curable composition and the base layer) and the solvent ratio of the curable composition, etc., can be adjusted depending on the desired film thickness. For example, the lifting speed can be set to 10 to 50 mm / sec.

[0077] After the coating film is formed, it is dried and cured. In the step of drying the coating film, the drying temperature, humidity, and drying time may be adjusted appropriately depending on the type of solvent, solvent ratio, film thickness, etc. The drying temperature is preferably 20 to 30°C, for example. The relative humidity during drying is preferably 40 to 70%. The drying time is preferably 30 to 300 seconds. It is also preferable to exhaust air during drying. The exhaust conditions are not particularly limited as long as they are sufficient to remove the solvent, but the exhaust air volume is preferably 10 to 50 m 3 / min is preferable, 30-50m 3 / min is more preferred. The dried coating film is then cured to obtain a surface layer. For example, curing can be performed by UV irradiation. The integrated light dose can be appropriately set depending on the material used. For example, it can be 300 to 2000 mJ / cm. 2 It can be said that:

[0078] The sum of the content of the first particles and the content of the second particles in the surface layer is preferably 4.0 to 37.0 mass%, more preferably 6.0 to 30.0 mass%, and even more preferably 14.0 to 28.0 mass%, based on the mass of the surface layer. Furthermore, the content of the first particles in the surface layer is preferably 0.2 to 27.0 mass%, more preferably 0.4 to 12.0 mass%, even more preferably 0.8 to 5.0 mass%, and even more preferably 1.0 to 2.0 mass%, based on the mass of the surface layer. The content of the second particles in the surface layer is preferably 3.8 to 30.0 mass %, more preferably 6.0 to 25.0 mass %, and even more preferably 10.0 to 25.0 mass %, based on the mass of the surface layer.

[0079] <<Electrophotographic image forming apparatus>> An electrophotographic image forming apparatus (hereinafter also referred to as "electrophotographic apparatus") will be described. FIG. 2 is a cross-sectional view of a full-color electrophotographic apparatus. The electrophotographic apparatus preferably includes an electrophotographic member as an intermediate transfer belt. The electrophotographic member is preferably an intermediate transfer belt. In FIG. 2, the electrophotographic apparatus is provided with a cylindrical electrophotographic seamless belt as an intermediate transfer belt 5. The electrophotographic photosensitive member 1 is a drum-shaped electrophotographic photosensitive member (hereinafter referred to as "photosensitive drum") that is repeatedly used as a first image carrier, and is rotationally driven in the direction of the arrow at a predetermined peripheral speed (process speed).

[0080] As the photosensitive drum 1 rotates, it is uniformly charged to a predetermined polarity and potential by a primary charger 2. 32 is a power source. The photosensitive drum is then exposed to image exposure 3 by an exposure means, forming an electrostatic latent image corresponding to a first color component image (e.g., a yellow color component image) of the desired color image. Examples of the exposure means include a color separation / imaging exposure optical system for a color original image, and a scanning exposure system using a laser scanner that outputs a laser beam modulated in accordance with time-series electrical digital pixel signals of image information.

[0081] Next, the electrostatic latent image on the photosensitive drum is developed with yellow toner Y, which is the first color, by the first developing device (yellow developing device 41). At this time, the second to fourth developing devices (magenta developing device 42, cyan developing device 43, black developing device 44) are turned off and do not act on the photosensitive drum 1, so the yellow toner image of the first color is not affected by the second to fourth developing devices. The electrophotographic belt 5 is rotated in the direction of the arrow at the same peripheral speed as the photosensitive drum 1.

[0082] When passing through the nip portion between the photosensitive drum 1 and the intermediate transfer belt 5, the yellow toner image on the photosensitive drum 1 is transferred to the outer peripheral surface of the intermediate transfer belt 5 by an electric field formed by a primary transfer bias applied from a power source 30 to the electrophotographic belt 5 via the primary transfer opposing roller 6 (primary transfer). After the first color yellow toner image has been transferred to the electrophotographic belt 5, the surface of the photosensitive drum 1 is cleaned by a cleaning device 13.

[0083] Similarly, a magenta toner image as a second color, a cyan toner image as a third color, and a black toner image as a fourth color are successively transferred onto the electrophotographic (intermediate transfer) belt 5 in a superimposed manner, thereby forming a composite color toner image corresponding to the target color image. The secondary transfer roller 7 is disposed on the underside of the electrophotographic belt 5 in a manner that allows it to be separated from the drive roller 8 and is supported in parallel therewith.

[0084] During the primary transfer process of the first to third color toner images from the photosensitive drum 1 to the electrophotographic belt 5, the secondary transfer roller 7 can be separated from the electrophotographic belt 5. The composite color toner image transferred onto the electrophotographic belt 5 is transferred to the transfer material P, which is a second image carrier, as follows.

[0085] First, the secondary transfer roller 7 is brought into contact with the electrophotographic belt 5, and the transfer material P is fed at a predetermined timing from the paper feed roller 11 through the transfer material guide 10 to the contact nip between the electrophotographic belt 5 and the secondary transfer roller 7. Then, a secondary transfer bias is applied from a power source 31 to the secondary transfer roller 7. This secondary transfer bias causes the composite color toner image to be transferred (secondary transfer) from the electrophotographic (intermediate transfer) belt 5 to the transfer material P, which is a second image carrier.

[0086] The transfer material P to which the toner image has been transferred is introduced into a fixing device 15 and heated and fixed. After the image transfer onto the transfer material P is completed, a cleaning roller 9 of a cleaning device is brought into contact with the electrophotographic belt 5, and a bias of the opposite polarity to that of the photosensitive drum 1 is applied. As a result, a charge of the opposite polarity to that of the photosensitive drum 1 is imparted to the toner (transfer residual toner) remaining on the electrophotographic belt 5 without being transferred to the transfer material P. 33 is a bias power supply. The transfer residual toner is electrostatically transferred to the photosensitive drum 1 at the nip portion with the photosensitive drum 1 and in the vicinity thereof, thereby cleaning the electrophotographic belt 5.

[0087] <<Evaluation method>> The methods for measuring and evaluating physical properties according to the present disclosure will be described. <Roughness arithmetic mean height Sa> The arithmetic mean height Sa of the surface layer was measured using a scanning white light interference microscope (product name: VertScan, manufactured by Ryoka Systems Co., Ltd.). Observation was performed at 50x magnification, and the obtained image was subjected to fourth-order surface correction, after which Sa was calculated from the corrected image. Images were taken at four points, Sa was measured, and the arithmetic mean value was used.

[0088] <Uneven gloss> The gloss unevenness of the surface layer of the electrophotographic member was measured using a handy gloss meter Gloss Checker IG-320 (manufactured by Horiba, Ltd.) Measurements were taken at 12 points in total, 3 points in the width direction and 4 points in the circumferential direction of the electrophotographic member, and the value obtained by subtracting the minimum value from the maximum value was taken as the gloss unevenness.

[0089] <Adhesion to other materials> The adhesion to the photosensitive drum of a full-color electrophotographic device (product name: LBP-5200, manufactured by Canon Inc.) was measured using a jig as shown in Figure 3. The electrophotographic belt b3 is stretched over a drive roller b1 equipped with a motor and torque meter, a driven roller b4, and a tension roller b6 that applies tension to the electrophotographic belt b3 serving as the electrophotographic member. The photosensitive drum b2 and backup roller b5 are the photosensitive drum and transfer roller of the LBP-5200, respectively.

[0090] The electrophotographic belt is rotated at 180 mm / sec without contacting the photosensitive drum, and the torque value at that time is measured. This value is designated "Tq1." Next, the maximum torque is measured when the electrophotographic belt is rotated at 180 mm / sec and the photosensitive drum is brought into contact with it at 700 gf. This value is designated "Tq2." The difference between "Tq2" and "Tq1" is used as an index for evaluating the adhesion between the electrophotographic belt and the photosensitive drum. If the difference is less than 0.10 Nm, the evaluation rank is designated "A," and if it is 0.10 Nm or more, the evaluation rank is designated "B."

[0091] Furthermore, when the electrophotographic belt and the photosensitive drum are brought into contact with each other, the photosensitive drum is fixed without being rotated, and the contact surface of the photosensitive drum is always in a new condition.

[0092] <Presence or absence of hetero-aggregates> A sample cut out from the surface layer of the electrophotographic member using a microtome or the like is observed using a TEM (Talos200 manufactured by FEI), and a cross-sectional photograph in the thickness direction of the surface layer is taken. In addition, elemental analysis was performed using a transmission electron microscope (EDX) with the EDX method (energy dispersive X-ray spectroscopy). Specifically, analysis was performed using a Talos 200 manufactured by FEI at an acceleration voltage of 200 kV. Each particle in the cross-sectional TEM photograph was clearly distinguished into a first particle and a second particle. If there was an aggregate containing both the first particle and the second particle, it was determined that a hetero-aggregate was present.

[0093] <Presence or absence of convex portions derived from hetero-aggregates> A sample cut out from the surface layer of the electrophotographic member using a microtome or the like is observed using a transmission electron microscope (TEM), and a cross-sectional photograph of the surface layer in the thickness direction is taken. This is done in the same manner as in the case of the presence or absence of hetero-aggregates. At this time, the outermost surface of the surface layer is included in the photograph. Furthermore, elemental analysis is performed by EDX (energy dispersive X-ray spectroscopy) in the same manner as in the above procedure for the presence or absence of hetero-aggregates, and each particle in the cross-sectional TEM photograph is clearly distinguished into first particles and second particles. The surface layer contains aggregates containing the first particles and the second particles, i.e., hetero-aggregates, and When convex portions reflecting the shape of the hetero-aggregates are formed on the outermost surface of the surface layer, the presence of convex portions derived from the hetero-aggregates is determined. Note that convex portions are recognized as portions where the hetero-aggregates themselves are exposed on the outer surface of the surface layer and portions where the matrix resin of the surface layer that covers the hetero-aggregates is raised, while other portions are recognized as non-convex portions.

[0094] <Major diameter and minor diameter of first particle> The major axis and minor axis of the first particle were determined by the following method. A sample cut out from the surface layer of the electrophotographic member using a microtome or the like was acid-decomposed and then observed with an SEM (ULTRA 55 manufactured by ZEISS). (Acid decomposition conditions) Acid: nitric acid (68%) 7.5ml + hydrochloric acid (30%) 0.5ml Sample size: 0.2g Acid decomposition equipment: ETHOS PRO (Milestone General) Heating: Heat to 70°C in 2 minutes → Cool to 50°C in 1 minute → Heat to 230°C in 20 minutes → Hold at 230°C for 20 minutes The minor and major diameters can be measured by image processing of SEM images. The image processing method used the image processing software ImageJ (NIH, version 1.51) and was carried out according to the following procedure. In the image area, the Auto button was selected, which automatically sets the threshold level, and binarization was performed to extract the shape of the chain particles. The binary image is then duplicated, and one image is subjected to particle analysis (Analyze Particles) to obtain the Feret diameter and area of ​​each individual particle chain, while the other binary image is subjected to skeletonization (Skeletonize) to obtain the skeleton length of each individual particle chain. The minor axis is calculated by dividing the total area of ​​chain particles by the total skeleton length. The major axis corresponds to the Feret's diameter of each particle. 100 particles are measured and the number average value is calculated.

[0095] <Number average particle size of primary particles of second particles> The number average particle size of the primary particles of the second particles is determined by the following method. A sample cut from the surface layer of the electrophotographic member using a microtome or the like is photographed using a TEM (FEI Talos 200) to take a cross-sectional photograph of the surface layer in the thickness direction. Elemental analysis is then performed using EDX (energy dispersive X-ray spectroscopy) to clearly distinguish the first particles and second particles that make up the hetero-aggregates in the TEM photograph. This is done in the same manner as the procedure for the presence or absence of hetero-aggregates. Next, the particle diameter of the second particles is determined by dividing the sum of the maximum length and the minimum length of the projected image of the second particles constituting the hetero-aggregate in the photograph by 2. This operation is performed for 100 second particles constituting the hetero-aggregate, and the arithmetic mean value of the obtained primary particle diameters is determined as the number-average particle diameter of the primary particles of the second particles.

[0096] <Particle content> The contents of the first particles and the second particles in the surface layer can be determined by the following method. The surface layer, peeled off from the electrophotographic member using a razor or similar tool, is measured in air at 400°C using a thermogravimetric analyzer (TGA) to obtain a profile of the weight loss rate versus measurement time. The initial mass is obtained from the profile. The mass at which the slope of the profile becomes constant is taken as the total mass of the particles. The value of [total mass of particles] / [initial mass] x 100 is taken as the sum (mass %) of the contents of the first and second particles in the surface layer.

[0097] In addition, the surface layer whose mass has been measured is heated to 400 degrees, and the mass of the residue is measured. The residue is then separated into first particles and second particles by centrifugation or other methods, and the mass of each particle is measured after drying. The mass of the first particles in the surface layer is calculated by dividing [mass of first particles] by [mass of surface layer] x 100. The content (mass%) of the second particles in the surface layer is defined as [mass of second particles] / [mass of surface layer]×100.

[0098] <Content of ionic conductive agent in surface layer> The presence of alkali metal cations and specific anions in the surface layer can be confirmed by immersing the surface layer in a solvent such as methanol or methyl ethyl ketone, extracting the components dissolved in the solvent, and analyzing them. Examples of analytical methods include liquid chromatography mass spectrometry, nuclear magnetic resonance spectroscopy, and ion chromatography. For example, first, the surface layer is peeled off from the electrophotographic member using a razor or the like, a sample is cut out from the surface layer, the mass of the surface layer is measured, and then the sample is immersed in methanol and subjected to 40 kHz ultrasound for 10 minutes to obtain an extract of the ion conductive agent. The obtained extract of the ion conductive agent is subjected to mass analysis using a liquid chromatography mass spectrometer (trade name: ThermoScientific LTQ Orbitrap XL, manufactured by Thermo Fisher Scientific) under the following conditions: [Mass spectrometry conditions] ·Direct introduction method ·Injection volume: 2μL Ionization method: Electrospray ionization (ESI)

[0099] In addition, the methanol solvent was removed from the extract obtained in the same manner, and the extract was then redissolved in deuterated methanol. 1 The analysis is carried out by H-NMR (trade name: AL400 type FT-NMR, manufactured by JEOL Ltd.). [Measurement conditions] Frequency: 400MHz Number of times accumulated: 32 ·Measurement temperature: 25℃ The above analysis allows the identification of specific anions.

[0100] The content of the alkali metal ion conductive agent in the surface layer can be determined by the following method: After removing methanol from the extract obtained in the same manner as above, the extract is redissolved in water, and the resulting aqueous solution is analyzed by ion chromatography, whereby the alkali metal ion conductive agent can be separated, identified, and quantified. Separately, similar to the method for determining the particle content described above, the surface layer whose mass has been measured is measured in air at 400°C using a thermogravimetric analyzer (TGA) to obtain a profile of the measurement time vs. weight loss rate. The initial mass is obtained from the profile. The mass at which the slope of the profile becomes constant is taken as the total mass of the particles. The (meth)acrylic resin content (mass%) in the surface layer is calculated from the value ([initial mass] - [total mass of particles]) / [initial mass]. From the above, the content (mmol / kg) of the ion conductive agent per 1 kg of the (meth)acrylic resin can be calculated. [Example]

[0101] The present disclosure will be described in detail below with reference to examples and comparative examples, but the present disclosure is not limited to these.

[0102] (base layer) The compounding ratio of the materials that make up the base layer is shown in Table 1. The structural formula and name of the ionic conductive agent are as shown in Table 2. First, the materials listed in Table 1 were melted and mixed in the amounts listed in Table 1 using a twin-screw kneading extruder (trade name: PCM43, manufactured by Ikegai Corporation) under the following conditions to obtain a thermoplastic resin composition. created something. Output: 6kg / h Screw rotation speed: 225 rpm Barrel temperature control: 270℃

[0103] The obtained thermoplastic resin composition was melt-extruded under the following conditions using a single-screw extruder (manufactured by Plastics Technology Research Institute Co., Ltd.) equipped with a spiral cylindrical die (inner diameter: 195 mm, slit width: 1.1 mm) at the tip to produce a cylindrical film of the following size. The cylindrical film thus obtained was used as the base layer. Output: 6kg / h Die temperature: 290℃ Size: Outer diameter 201mm, thickness 70μm

[0104] (Surface layer) Furthermore, the compounding ratios of materials constituting the curable composition for forming the surface layer are shown in Table 3. In Table 3, when the material is a slurry, the solid components were adjusted to the compounding ratio shown in Table 3. The curable composition was prepared as follows. A slurry in which component (a) was dispersed in a solvent, a slurry in which component (b) was dispersed in a solvent, and a solution in which component (c) was dissolved in a solvent were prepared in advance. These, along with components (d), (e), and a polymerization initiator in the formulations shown in Table 3, were placed in a container equipped with a stirrer and stirred at room temperature for 30 minutes to obtain a curable composition.

[0105] The base layer obtained by the above extrusion molding was fitted onto the outer periphery of a cylindrical mold, the ends were sealed, and the mold was then immersed in a container filled with a curable composition and pulled up so that the relative speed between the liquid surface of the curable composition and the base layer was constant, thereby forming a coating film of the curable composition for forming a surface layer on the surface of the base layer. In the examples and comparative examples, the lifting speed was set to 10 to 50 mm / sec, and the thickness of the coating film of the curable composition was adjusted to 2 μm. The curable compositions were mixed according to the formulations shown in Table 3. After forming the coating film of the curable composition, the coating film was heated in an environment of a temperature of 23°C and a relative humidity of 55%, with an exhaust air volume of 40 m 3 The dried coating was then dried for 1 minute under an exhaust gas at a rate of 1 / min. Then, the dried coating was irradiated with a UV irradiator (product name: UE06 / 81-3, manufactured by Eye Graphics Co., Ltd.) with an accumulated light dose of 600 mJ / cm. 2 The coating was cured by irradiating it with ultraviolet light until the thickness reached 100 μm, forming a surface layer. The thickness of the resulting surface layer was 2 μm, as determined by observing the cross section with an electron microscope.

[0106] Tables 4 and 5 show the combinations of base layers and curable compositions used in the examples and comparative examples, as well as the evaluation results thereof.

[0107] [Table 1] (f) The following resins were used: f-1 Teijin Limited "TN-8065S" (product name); polyethylene naphthalate

[0108] [Table 2]

[0109] [Table 3]

[0110] The materials used are as follows. The parts in the table indicate parts by mass. a-1 Nissan Chemical Co., Ltd. "IPA-ST-UP" (product name); chain silica particle slurry a-2 "Sururia 4110" (product name) manufactured by JGC Catalysts and Chemicals Co., Ltd.; hollow silica particle slurry a-3 Nissan Chemical Co., Ltd. "IPA-ST-L" (product name); solid silica particle slurry

[0111] (Preparation of b-1) 12.0 g of antimony-containing tin oxide particles (product name: SN-100P, manufactured by Ishihara Sangyo Kaisha, Ltd.), 0.12 g of acetic acid (manufactured by Kishida Chemical Co., Ltd.) as an organic acid, 0.03 g of trioctylamine (manufactured by Kishida Chemical Co., Ltd.) as an amine compound, and 48.0 g of isopropyl alcohol (manufactured by Kishida Chemical Co., Ltd.) as a solvent were weighed and placed in a 250 mL zirconia container. Furthermore, 108.3 g of zirconia beads with a diameter of 0.5 mm were added to the container. The mixture was then stirred at 400 rpm for 3 hours using a planetary ball mill (Model: P-6, manufactured by Fritsch Japan Co., Ltd.) and the beads were then removed by mesh filtration to obtain dispersion b-1 with a solids concentration of ATO particles (i.e., the content of ATO particles in the dispersion) of 20 mass%.

[0112] (Preparation of b-2) 100 g of antimony-containing tin oxide particles (product name: SN-100P, manufactured by Ishihara Sangyo Kaisha, Ltd.) was placed in a Henschel mixer, and trimethoxymethylsilane was added while rotating the mixer. 3.79 g of KBM-13 (product name, manufactured by Shin-Etsu Silicones Co., Ltd.) was added dropwise and stirred for 2 hours. The powder was then removed and dried at 100°C for 1 hour in a drying oven to obtain ATO particles with a surface treatment rate of 30%. 12.50 g of these ATO particles with a surface treatment rate of 30%, 0.09 g of trioctylamine (Kishida Chemical Co., Ltd.) as an amine compound, 0.50 g of phosphate polyester (trade name: BYK111, BYK-Chemie GmbH, molecular weight approximately 800 to 1500) as a phosphorus compound, and 18.13 g of 2-butanone (Kishida Chemical Co., Ltd.) as a solvent were weighed and placed in a 250 mL zirconia container. 42.86 g of zirconia beads with a diameter of 0.5 mm were then added to the container. The mixture was then stirred at 400 rpm for 3 hours using a planetary ball mill (Model: P-6, manufactured by Fritsch Japan Co., Ltd.) and the beads were then removed by mesh filtration to obtain dispersion b-2 with a solids concentration of ATO particles (i.e., the content of ATO particles in the dispersion) of 40 mass%.

[0113] c-1 "Aronix M-305" (product name) manufactured by Toagosei Co., Ltd. In the table, *1 indicates the following: *1 BASF "Irgacure 907" (product name)

[0114] [Table 4] In the table, the major axis of component (a) indicates the number average value, and the primary particle diameter of component (b) indicates the number average particle diameter of the primary particles. The amount of component (a) indicates the content [mass %] of the first particles in the surface layer. The amount of component (b) indicates the content [mass %] of the second particles in the surface layer. The sum of the (a) component and the (b) component represents the total content [mass %] of the first particles and the second particles in the surface layer.

[0115] [Table 5]

[0116] The number average value of the major axis and the major axis / minor axis ratio of the inorganic oxide particles constituting the hetero-aggregates, and the number average particle size of the primary particles of the antimony-doped tin oxide particles were as shown in Table 4 above. The arithmetic mean height Sa of the outer surface of the surface layer and the content of the alkali metal ion conductive agent relative to the (meth)acrylic resin in the surface layer were as shown in Table 5 above.

[0117] The evaluation results of the examples and comparative examples will be described below. In Examples 1 to 13, the content of the ionic conductive agent composed of alkali metal cations and specific anions relative to the (meth)acrylic resin in the surface layer is 1.0 to 5.0 mmol / kg. Furthermore, Examples 1 to 13 have convex portions derived from heteroaggregates composed of component (a) and component (b), and have an arithmetic mean height Sa of 0.10 to 0.70 μm. Therefore, it is believed that adhesion to other members is suppressed, color misregistration is unlikely to occur, and high-quality images can be obtained. can be obtained.

[0118] In Comparative Examples 1 and 2, the content of the ionic conductive agent composed of alkali metal cations and specific anions relative to the surface layer acrylic resin in the surface layer is less than 1.0 mmol / kg. Furthermore, Comparative Examples 1 and 2 do not have convex portions derived from heteroaggregates composed of components (a) and (b), and the arithmetic mean height Sa is less than 0.10 μm. Therefore, it is believed that the adhesion to other components is high, and color misalignment is likely to occur.

[0119] Comparing Example 2 with Examples 12 and 13, the inorganic oxide particles of Example 2, which are component (a), have a larger long diameter / short diameter than those of Examples 12 and 13, and are chain-like particles. This is thought to facilitate interaction with the antimony-doped tin oxide particles of component (b), which facilitates the formation of convex portions derived from hetero-aggregates, resulting in a larger arithmetic mean height Sa.

[0120] Furthermore, comparing Examples 4, 6, and 7 with Examples 8 and 9, Examples 4, 6, and 7 contain a larger amount of component (b-2), which is antimony-doped tin oxide particles treated with a silane coupling agent, at 5 parts by mass or more per 100 parts by mass of the (meth)acrylic resin, than Examples 8 and 9. This reduces gloss unevenness (irregularities with a period smaller than Sa) and is thought to reduce unevenness in the adhesion suppression effect with other components, resulting in higher quality images.

[0121] The present disclosure relates to the following configurations or methods. (Configuration 1) Substrate, and a surface layer directly adjacent to the base layer, the surface layer comprises a hetero-aggregate of first particles and second particles different from the first particles; The first particles include: The inorganic oxide particles have a number average major axis of 30 to 100 nm, The second particles are antimony-doped tin oxide particles; and the number average particle size of the primary particles of the second particles is 5 to 40 nm; the surface layer has convex portions derived from the hetero-aggregate on an outer surface opposite to the surface facing the base layer, The arithmetic mean height (Sa) of the outer surface is 0.10 to 0.70 μm, The surface layer is an ion conductive agent containing at least one anion selected from the group consisting of anions represented by the following formulas (A1) to (A4) and an alkali metal cation; (meth)acrylic resin, an electrophotographic member, characterized in that the content of the ion conductive agent relative to the (meth)acrylic resin in the surface layer is 1.0 to 5.0 mmol / kg; TIFF2026023128000009.tif153168 R1 to R4 are each independently a hydrogen atom, a hydrocarbon group having 1 to 18 carbon atoms, or an alkoxy group having 1 to 18 carbon atoms. (Configuration 2) 2. The electrophotographic member according to claim 1, wherein the number average value of the ratio of the major axis to the minor axis (major axis / minor axis) of the first particles is 3 to 8. (Configuration 3) 3. The electrophotographic member according to claim 1, wherein the first particles are chain-like silica particles. (Configuration 4) the antimony-doped tin oxide particles are treated with a silane coupling agent; 4. The electrophotographic member according to any one of configurations 1 to 3, wherein the content of the antimony-doped tin oxide treated with a silane coupling agent is 3 to 20 parts by mass per 100 parts by mass of the (meth)acrylic resin. (Configuration 5) 5. The electrophotographic member according to any one of Configurations 1 to 4, wherein the electrophotographic member is an intermediate transfer belt. (Configuration 6) 6. An electrophotographic image forming apparatus comprising the electrophotographic member according to any one of Configurations 1 to 5 as an intermediate transfer belt. (Method 7) 1. A method of manufacturing an electrophotographic member having a base layer and a surface layer directly in contact with the base layer, comprising: The manufacturing method comprises: providing a base layer; A step of preparing a curable composition containing the following components (a) to (e): forming a coating of the curable composition on one surface of the base layer and drying the coating; and curing the dried coating; A method for manufacturing an electrophotographic member, comprising: (a) first particles that are inorganic oxide particles having a number-average major axis size of 30 to 100 nm; (b) second particles different from the first particles, having a number-average particle size of primary particles of 5 to 40 nm, the second particles including antimony-doped tin oxide particles; (c) (meth)acrylic monomers; (d) at least one solvent selected from the group consisting of 2-butanone and 4-methyl-2-pentanone; (e) a salt containing at least one anion selected from the group consisting of anions represented by the following formulae (A1) to (A4) and an alkali metal cation; TIFF2026023128000010.tif153168 R1 to R4 are each independently a hydrogen atom, a hydrocarbon group having 1 to 18 carbon atoms, or an alkoxy group having 1 to 18 carbon atoms. [Explanation of symbols]

[0122] a1 base layer, a2 surface layer, 1 photosensitive drum, 2 primary charger, 3 image exposure, 41 yellow developer, 42 magenta developer, 43 cyan developer, 44 black developer, 5 electrophotographic member (intermediate transfer belt), 6 primary transfer opposing roller, 7 secondary transfer roller, 8 drive roller, 9 cleaning roller, 10 transfer material guide, 11 paper feed roller, 12 tension roller, 13 Cleaning device, 15 Fixing unit, 30, 31, 32, 33 Power supply, P Transfer material, b1 drive roller, b2 photosensitive drum, b3 electrophotographic member (intermediate transfer belt), b4 driven roller, b5 backup roller, b6 tension roller

Claims

1. Substrate, and a surface layer directly adjacent to the base layer, the surface layer comprises a hetero-aggregate of first particles and second particles different from the first particles; The first particles include: The inorganic oxide particles have a number-average major axis size of 30 to 100 nm, The second particles are antimony-doped tin oxide particles; and the number average particle size of the primary particles of the second particles is 5 to 40 nm; the surface layer has convex portions derived from the hetero-aggregate on an outer surface opposite to the surface facing the base layer, The arithmetic mean height (Sa) of the outer surface is 0.10 to 0.70 μm, The surface layer is an ion conductive agent containing at least one anion selected from the group consisting of anions represented by the following formulas (A1) to (A4) and an alkali metal cation; (meth)acrylic resin, an electrophotographic member, characterized in that the content of the ion conductive agent relative to the (meth)acrylic resin in the surface layer is 1.0 to 5.0 mmol / kg; R １ ~R ４ are each independently a hydrogen atom, a hydrocarbon group having 1 to 18 carbon atoms, or an alkoxy group having 1 to 18 carbon atoms.

2. 2. The electrophotographic member according to claim 1, wherein the number average value of the ratio of the major axis to the minor axis (major axis / minor axis) of said first particles is 3 to 8.

3. 2. An electrophotographic member according to claim 1, wherein said first particles are chain-like silica particles.

4. the antimony-doped tin oxide particles are treated with a silane coupling agent; 2. The electrophotographic member according to claim 1, wherein the content of the antimony-doped tin oxide treated with the silane coupling agent is 3 to 20 parts by mass per 100 parts by mass of the (meth)acrylic resin.

5. 2. The electrophotographic member of claim 1, wherein the electrophotographic member is an intermediate transfer belt.

6. 6. An electrophotographic image forming apparatus comprising the electrophotographic member according to claim 1 as an intermediate transfer belt.

7. 1. A method of manufacturing an electrophotographic member having a base layer and a surface layer directly in contact with the base layer, comprising: The manufacturing method comprises: providing a base layer; A step of preparing a curable composition containing the following components (a) to (e): forming a coating of the curable composition on one surface of the base layer and drying the coating; and curing the dried coating; A method for producing an electrophotographic member, comprising: (a) first particles that are inorganic oxide particles having a number-average major axis size of 30 to 100 nm; (b) second particles different from the first particles, the number-average particle size of the primary particles being 5 to 40 nm, the second particles comprising antimony-doped tin oxide particles; (c) (meth)acrylic monomer; (d) at least one solvent selected from the group consisting of 2-butanone and 4-methyl-2-pentanone; (e) a salt containing at least one anion selected from the group consisting of anions represented by the following formulas (A1) to (A4) and an alkali metal cation; R １ ~R ４ are each independently a hydrogen atom, a hydrocarbon group having 1 to 18 carbon atoms, or an alkoxy group having 1 to 18 carbon atoms.

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