Conductive dispersion liquid, coating material, and member, and electronic photography image forming device

Abstract

To provide a dispersion liquid of conductive particles capable of improving the surface roughness of a film while forming a highly conductive film.SOLUTION: A conductive dispersion liquid comprising tin oxide particles and a dispersion medium, wherein the conductive dispersion liquid further comprises an organic acid, a phosphorus compound, and an amine compound, the tin oxide particles are dispersed in the dispersion medium, a cumulant mean particle size of the tin oxide particles in the conductive dispersion liquid is from 90 to 400 nm, and the organic acid, the phosphorus compound, and the amine compound are dissolved in the dispersion medium; The tin oxide particles include antimony-containing tin oxide particles A not treated with a silane coupling agent and antimony-containing tin oxide particles B treated with a silane coupling agent.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a conductive dispersion, a coating material for forming a resin film, a resin film, a member, and an electrophotographic image forming apparatus. [Background technology]

[0002] A dispersion of antimony-containing tin oxide (ATO) particles, which are transparent to visible light, dispersed in a dispersion medium can be mixed with binder resins such as acrylic resins or urethane resins to create coating paints with high transparency and excellent conductivity. For this reason, ATO particles are often used in electrical and electronic material applications such as electrode materials for displays such as liquid crystal and organic electroluminescence (EL) displays, electrode materials for solar power generation, photoreceptors used in electrophotographic devices, and conductive layers for intermediate transfer belts. Furthermore, because ATO particles have the ability to absorb electromagnetic waves such as infrared and ultraviolet, a transparent resin film that can block infrared and other heat rays can be easily produced by forming a film of resin paint containing ATO particles on a substrate. Such paints are used in fields where infrared and ultraviolet blocking properties are required, such as window materials for automobiles, trains, ships, and homes.

[0003] Patent Document 1 proposes a method for forming chain-like particle clusters of ATO particles in a dispersion liquid. It is disclosed that this method makes it easy for the ATO particles to form conductive paths even in a coating film, resulting in an ATO dispersion liquid that can achieve high conductivity. On the other hand, Patent Document 2 proposes a surface-modified anhydrous zinc antimonate colloidal particle sol obtained by coating the surfaces of anhydrous zinc antimonate colloidal particles with a silicon-containing substance. It discloses that this method makes it possible to obtain an organic solvent sol of anhydrous zinc antimonate that is dispersed in a state close to primary particles without aggregation. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-211155 [Patent Document 2] Japanese Patent Application Publication No. 11-314918 Summary of the Invention [Problem to be solved by the invention]

[0005] At least one aspect of the present disclosure is directed to providing a dispersion of conductive particles that can form a highly conductive film while improving the surface roughness of the film. Also, at least one aspect of the present disclosure is directed to providing a paint for forming a resin film that can form a resin film that has both high conductivity and good surface roughness. Furthermore, at least one aspect of the present disclosure is directed to providing a resin film that combines high conductivity and good surface roughness. Still further, at least one aspect of the present disclosure is directed to providing a member having a surface that combines high conductivity and good surface roughness. In addition, at least one aspect of the present disclosure is directed to providing an electrophotographic image forming apparatus that includes the member. [Means for solving the problem]

[0006] According to at least one aspect of the present disclosure, A conductive dispersion liquid containing tin oxide particles and a dispersion medium, the conductive dispersion further contains an organic acid, a phosphorus compound, and an amine compound; the tin oxide particles are dispersed in the dispersion medium, the tin oxide particles in the conductive dispersion have a cumulant average particle size of 90 to 400 nm; the organic acid, the phosphorus compound, and the amine compound are dissolved in the dispersion medium; The conductive dispersion liquid is provided, in which the tin oxide particles include antimony-containing tin oxide particles A that have not been treated with a silane coupling agent, and antimony-containing tin oxide particles B that have been treated with a silane coupling agent.

[0007] Furthermore, according to at least one aspect of the present disclosure, A paint for forming a resin film containing a resin At least one selected from the group consisting of the resin and a precursor of the resin; Tin oxide particles; Organic acids and a phosphorus compound; an amine compound; Including, The tin oxide particles include antimony-containing tin oxide particles A that have not been treated with a silane coupling agent, and antimony-containing tin oxide particles B that have been treated with a silane coupling agent, and a coating material for forming a resin film is provided.

[0008] Furthermore, according to at least one aspect of the present disclosure, there is provided a resin film containing a resin, the resin film being a cured product of a coating film of the above-mentioned paint for forming a resin film. Furthermore, according to at least one aspect of the present disclosure, there is provided a member having a substrate and a resin film containing a resin on a surface of the substrate, wherein the resin film is a cured product of a coating film of the above-mentioned paint for forming a resin film. Additionally, according to at least one aspect of the present disclosure, there is provided an electrophotographic image forming apparatus including the above member as an intermediate transfer member. [Effects of the Invention]

[0009] According to at least one aspect of the present disclosure, a dispersion of conductive particles can be obtained that can form a highly conductive film while improving the surface roughness of the film. Also, according to at least one aspect of the present disclosure, a paint for forming a resin film can be obtained that can form a resin film that has both high conductivity and good surface roughness. Furthermore, according to at least one aspect of the present disclosure, a resin film having both high conductivity and good surface roughness can be obtained. Furthermore, according to at least one aspect of the present disclosure, a member having a surface having both high conductivity and good surface roughness can be obtained. In addition, according to at least one aspect of the present disclosure, an electrophotographic image forming apparatus including the member can be obtained. [Brief explanation of the drawings]

[0010] [Figure 1] An explanatory diagram of the estimated mechanism of the effect of the paint for forming a resin film according to the present disclosure. [Figure 2] 1 is a schematic cross-sectional view illustrating an example of an electrophotographic image forming apparatus according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] In this specification, unless otherwise specified, the expressions "XX or more and YY or less" or "XX to YY" representing a numerical range mean a numerical range including the lower and upper limits, which are the endpoints. Furthermore, when a numerical range is described in stages, the upper and lower limits of each numerical range can be arbitrarily combined. Furthermore, in this disclosure, 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 XX may be selected, and the same applies to YY and ZZ. Furthermore, in the present disclosure, the unit of surface resistivity (LOGΩ / □) means the logarithmic notation of (Ω / square).

[0012] The present inventors have confirmed that the technology disclosed in Patent Document 1 can impart conductivity to a coating film even with a small amount of ATO by causing chain-like aggregation or clustering of ATO particles in the coating film or dispersion. However, it was found that when the dispersion is mixed with a solution of a resin or a resin precursor to prepare a coating material, the resin film formed using this coating material has a roughened surface, resulting in increased surface roughness.

[0013] For example, the surface of a conductive resin member, such as an intermediate transfer belt used as an electrophotographic member, may be prepared as follows. That is, a coating material is prepared by mixing a dispersion liquid with a solution of a resin or a resin precursor, and a resin film formed using this coating material may be used as the surface of the resin member. In this case, the surface roughness of the resin film is high, and it has been found that wear is accelerated in sliding members that face the intermediate transfer belt, such as a resin cleaning blade that cleans residual toner on the intermediate transfer belt, shortening the member's lifespan. Therefore, it has been recognized that this method is difficult to apply to members that require a smooth surface, such as an intermediate transfer belt.

[0014] On the other hand, it has been confirmed that the surface-modified anhydrous zinc antimonate colloidal particle sol obtained by coating the surfaces of anhydrous zinc antimonate colloidal particles with a silicon-containing substance, as described in Patent Document 2, has excellent particle dispersibility and shows little change in the dispersion state even after long-term storage. However, it has been found that a resin film formed using a paint prepared by mixing a dispersion containing the sol with a solution of a resin or a resin precursor has insufficient conductivity.

[0015] The reason why the resin film did not have sufficient conductivity is presumed to be as follows: When using electronically conductive particles such as ATO particles to impart conductivity, it is necessary to cause the particles to aggregate in the coating film to form conductive paths through which electrons can flow. However, it is thought that the resin film formed from a paint prepared using a dispersion of highly dispersed ATO particles did not exhibit sufficient conductivity because it was difficult to sufficiently develop conductive paths due to the ATO particles in the resin film.

[0016] Therefore, the present inventors have conducted extensive research to obtain a dispersion of ATO particles that can form a resin film that has both high conductivity and good surface roughness. As a result, it was found that the conductive dispersion of the present disclosure is effective in achieving the above object.

[0017] The conductive dispersion of the present disclosure comprises: A conductive dispersion liquid containing tin oxide particles and a dispersion medium, the conductive dispersion further contains an organic acid, a phosphorus compound, and an amine compound; the tin oxide particles are dispersed in the dispersion medium, the tin oxide particles in the conductive dispersion have a cumulant average particle size of 90 to 400 nm; the organic acid, the phosphorus compound, and the amine compound are dissolved in the dispersion medium; The tin oxide particles include antimony-containing tin oxide particles A that have not been treated with a silane coupling agent, and antimony-containing tin oxide particles B that have been treated with a silane coupling agent.

[0018] The estimated mechanism by which the dispersion liquid can form a resin film having high conductivity and good surface roughness will be explained using Figure 1. Note that the mechanism explained below is merely an estimate and is not limited to this.

[0019] 1A to 1C are explanatory diagrams of a presumed mechanism of the effect manifestation of the coating material for forming a resin film according to the present disclosure. A coating material was prepared by mixing the dispersion liquid of the present disclosure with a solution of a resin or a resin precursor. A cross-sectional schematic diagram of a resin film formed using this coating material is shown in FIG. 1B. For comparison, FIG. 1A shows a cross-sectional schematic diagram of a resin film formed in the same manner except that only antimony-containing tin oxide particles A (hereinafter also referred to as ATO particles A) 101a that have not been treated with a silane coupling agent were used as the tin oxide particles 101. FIG. 1C shows a cross-sectional schematic diagram of a resin film formed in the same manner when only antimony-containing tin oxide particles B (hereinafter also referred to as ATO particles B) 101b that have been treated with a silane coupling agent were used as the tin oxide particles 101. In each figure, tin oxide particles 101 are dispersed in resin 102, which serves as a binder resin.

[0020] A coating material is prepared by mixing a dispersion containing only ATO particles A101a as tin oxide particles with a solution of resin or resin precursors. In the resin film formed using this coating material, the ATO particles A101a tend to aggregate during the drying process. This facilitates the formation of conductive paths, resulting in high conductivity. However, aggregation of the ATO particles A101a increases the roughness of the coating film surface (Figure 1A). This makes it difficult to apply this coating material to components requiring a smooth surface, such as intermediate transfer belts used in electrophotography.

[0021] On the other hand, the ATO particles B101b are highly dispersed in the dispersion liquid because they have been treated with a silane coupling agent. A coating material is prepared by mixing a dispersion liquid in which only the ATO particles B101b are dispersed as tin oxide particles 101 with a solution of resin or resin precursor, and the ATO particles B101b are also thought to be highly dispersed in the resin film formed using this coating material (Figure 1C). Therefore, the uniform dispersion of the ATO particles B101b in the resin film reduces and improves the surface roughness, but conversely, the ATO particles B101b are less likely to aggregate. This makes it difficult to form conductive paths, and conductivity is thought to be difficult to achieve.

[0022] However, the dispersion of the present disclosure contains ATO particles A101a and ATO particles B101b. Therefore, it is believed that the aggregation effect of the ATO particles A101a and the high dispersion effect of the ATO particles B101b both work together to form numerous fine conductive paths as shown in Figure 1B. The dispersion of the present disclosure is mixed with a solution of a resin or a resin precursor to prepare a coating material, and the resin film formed using this coating material is believed to have both high conductivity and good surface roughness due to the above-mentioned effects. Each component of the conductive dispersion will be described in detail below.

[0023] The conductive dispersion can be obtained by mixing ATO particles A, ATO particles B, an organic acid, a phosphorus compound, an amine compound, and a dispersion medium, and dispersing the mixture in a dispersing device.

[0024] The method for producing the conductive dispersion is not particularly limited, but examples include a production method having a preparation step A in which ATO particles A, an organic acid, and a dispersant are added to a dispersion medium and the resulting mixture is dispersed to prepare dispersion A, a preparation step B in which ATO particles B and a dispersant are added to a dispersion medium and the resulting mixture is dispersed to prepare dispersion B, and a mixing step in which dispersion A and dispersion B are mixed. In this case, the ratio of dispersion A to dispersion B in the mixing step can be any ratio.

[0025] The method for producing a conductive dispersion may also include a preparation step C of adding ATO particles A, ATO particles B, and a dispersant to a dispersion medium and dispersing the resulting mixture. Even when the materials are dispersed simultaneously using a dispersion device in this manner, a dispersion with the same physical properties as that produced by the above-mentioned production method in which dispersion A and dispersion B are prepared separately and then mixed together can be produced. The dispersion method for the dispersion liquid is not particularly limited. For example, a wet dispersion method for inorganic particles may be used. It is possible to use a micronizing device such as a media mill such as a ball mill, a bead mill, or a side grinder, a high-pressure homogenizer, or an ultrasonic disperser, which is capable of highly dispersing the above.

[0026] Each component of the conductive dispersion will be described in detail below. The conductive dispersion liquid contains tin oxide particles. The tin oxide particles are dispersed in a dispersion medium. The tin oxide particles include antimony-containing tin oxide particles A that have not been treated with a silane coupling agent, and antimony-containing tin oxide particles B that have been treated with a silane coupling agent. The total content of ATO particles A and ATO particles B in the tin oxide particles is not particularly limited and can be, for example, 95 to 100% by mass relative to the tin oxide particles. The tin oxide particles preferably consist of ATO particles A and ATO particles B, but may also contain other particles. Examples of other particles include indium-containing tin oxide particles, aluminum-containing tin oxide particles, and tin oxide particles containing no metal elements other than tin. The content of other particles is not particularly limited and can be, for example, 0.1 to 5% by mass relative to the tin oxide particles.

[0027] [Antimony-containing tin oxide particles (ATO particles A) that have not been treated with a silane coupling agent] The tin oxide particles include antimony-containing tin oxide particles A that have not been treated with a silane coupling agent. That is, the conductive dispersion liquid includes ATO particles A. Antimony-containing tin oxide refers to tin oxide particles containing a small amount of an antimony compound. As such ATO particles, those generally available commercially as antimony-doped tin oxide can be used. The isoelectric point of the ATO particles A is not particularly limited, but can be, for example, 2.0 to 4.0, 2.0 to 3.5, or 2.2 to 3.1. Compared to zinc oxide-based conductive particles (such as aluminum-doped zinc oxide), ATO particles A have a higher conductivity of the particles themselves, making them suitable as a raw material for dispersions. Furthermore, zinc oxide is naturally produced as zincite, a rare mineral that is only mined in a limited number of mines around the world. On the other hand, cassiterite, the raw material for tin oxide, has the advantage of being easily secured in the supply chain because it is mined in mines in multiple countries.

[0028] Furthermore, transparent conductive particles such as indium-containing tin oxide (ITO) particles have even higher conductivity than ATO particles A and are suitable as raw materials for transparent electrode films, etc. However, indium compounds are more expensive than antimony compounds, resulting in higher material costs than when ATO particles A are used. Furthermore, ATO particles A have the ability to absorb wavelengths in the ultraviolet and infrared regions, making them highly versatile as electrical and optical functional materials. As described above, ATO particles A are in high market demand as a raw material for dispersions due to their low cost and geopolitical risk.

[0029] The cumulant average particle diameter of the ATO particles A in the conductive dispersion is preferably 1 to 1500 nm, more preferably 90 to 1000 nm, even more preferably 100 to 1000 nm, and particularly preferably 100 to 500 nm. When the average particle diameter of the ATO particles A is within the above range, the ATO particles A can be easily dispersed in the dispersion, and a coating film having high transparency can be obtained. The cumulant average particle diameter refers to the average particle diameter obtained by analysis using the cumulant method, as described below. A specific method for measuring the cumulant average particle diameter of the ATO particles B will be described later.

[0030] The method for producing ATO particles A is not particularly limited, but examples include a method of co-precipitation and calcination using a hydrolyzable tin compound and a hydrolyzable antimony compound as raw materials. In this method, tin and antimony compounds are simultaneously hydrolyzed in the same solution, thereby coprecipitating hydrated oxides of tin and antimony to obtain a coprecipitate. After washing to remove salt adhering to the precipitate, ATO particles A are obtained by calcining at 400°C or higher. When ATO particles A are used as a transparent conductive material, in order to obtain high transparency and sufficient conductivity, the content of antimony oxide in the ATO particles is preferably 1 to 30 parts by mass, more preferably 5 to 15 parts by mass, per 100 parts by mass of tin oxide particles.

[0031] The content of ATO particles A in the conductive dispersion is preferably 10 to 90 parts by mass, more preferably 20 to 80 parts by mass, and even more preferably 25 to 75 parts by mass, relative to 100 parts by mass of the total of ATO particles A and ATO particles B (described below) contained in the conductive dispersion. Within this range, the surface resistivity of the resin film tends to decrease, and the surface roughness tends to decrease. Furthermore, as the content of ATO particles A increases, the surface resistivity tends to decrease, and the surface roughness tends to increase. Furthermore, the ATO particles A may contain other elements such as silicon oxide in addition to antimony oxide, as long as the electrical conductivity and transparency are not impaired.

[0032] [Antimony-containing tin oxide particles treated with a silane coupling agent (ATO particles B)] The tin oxide particles contain antimony-containing tin oxide particles B that have been treated with a silane coupling agent. That is, the conductive dispersion contains ATO particles B. The ATO particles B can be obtained by surface treating the above-mentioned ATO particles A with a silane coupling agent. That is, the ATO particles B can also be said to be ATO particles A that have been treated with a silane coupling agent. Whether the tin oxide particles contain ATO particles B is confirmed by the method described below. The surface treatment of ATO particles with a silane coupling agent can be performed by any known method, including, but not limited to, a dry method in which the ATO particles are stirred in a Henschel mixer or the like and the silane coupling agent is added by spraying or dripping into the stirring vessel, or a wet method in which the ATO particles are stirred at high speed together with the silane coupling agent in the presence of a solvent.

[0033] The silane coupling agent is not particularly limited as long as it can improve compatibility with the dispersion medium, but for example, trimethoxymethylsilane, triethoxymethylsilane, trimethoxypropylsilane, triethoxypropylsilane, etc. can be suitably used. Other examples that can be used include vinyltrimethoxysilane and vinyltriethoxysilane, which have a vinyl group in the molecular structure, 3-glycidoxypropylmethyldimethoxysilane, which have an epoxy group, 3-methacryloxypropyltrimethoxysilane and 3-methacryloxypropyltriethoxysilane, which have a methacryl group, and 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane, which have an amino group. Among them, trimethoxysilane and 3-aminopropyltriethoxysilane can be used. Methoxymethylsilane is preferred.

[0034] The amount of silane coupling agent treatment (hereinafter also referred to as surface treatment rate) of the antimony-containing tin oxide particles B used as a raw material for the conductive dispersion is preferably 1.0 to 50.0 mass%. If the surface treatment rate is 1.0 mass% or less, the dispersion effect of the ATO particles B will be reduced, and when a coating film is formed, the surface roughness of the coating film may increase. Furthermore, if the surface treatment rate is 50.0 mass% or more, even when mixed with the ATO particles A, it may be difficult to form conductive paths in the coating film, and conductivity may be difficult to exhibit. The surface treatment rate is more preferably 5.0 to 50.0% by mass, and even more preferably 10.0 to 50.0% by mass. As the surface treatment rate increases, the surface resistivity tends to increase and the surface roughness tends to decrease. The surface treatment rate can be adjusted by changing the amount of silane coupling agent used when preparing ATO particles B. The surface treatment rate can be measured by analyzing ATO particles B, which are used as a raw material for the conductive dispersion, by XRF.

[0035] When the antimony-containing tin oxide particles B contained in the conductive dispersion are measured by fluorescent X-ray, the proportion of silicon element to all elements measured is preferably 5.0 to 15.0 mass%, more preferably 5.0 to 12.0 mass%. The specific measurement method is as follows: As described below, measurement of ATO particles B by fluorescence X-ray is performed by mixing ATO particles A and ATO particles B in a conductive dispersion with a mixture of methyl ethyl ketone and water in a mass ratio of 1:1, separating the particles into ATO particles A and ATO particles B, and using the resulting ATO particles B. The measurement device used was wavelength dispersive X-ray fluorescence spectroscopy (XRF). Since ATO particles A were not subjected to silane coupling treatment, no Si was detected. On the other hand, Si derived from silane coupling was detected in ATO particles B. Specifically, the dispersion medium contained in the conductive dispersion is first dried to separate ATO particles A and ATO particles B from the conductive dispersion. The remaining solid particles are then mixed with a mixture of methyl ethyl ketone (MEK) and water in a mass ratio of 1:1, shaken well, and then allowed to stand. After sufficient layer separation into a water layer and an MEK layer, the particles that have migrated to the water layer (ATO particles A) and the particles that have migrated to the MEK layer (ATO particles B) are separated. The water or MEK is then evaporated. The ATO particles B obtained after evaporation are analyzed by XRF to calculate the ratio of silicon atoms to all elements.

[0036] When ATO particles B are measured using the above measurement method, the fact that elemental silicon is measured indicates that ATO particles B are ATO particles treated with a silane coupling agent. As in the above measurement method, by using a mixed solution of MEK and water, ATO particles B are contained in the MEK layer, which is an organic layer. This makes it possible to remove unreacted silane coupling agent even if ATO particles B contain unreacted silane coupling agent. In other words, the fact that elemental silicon is measured using the above measurement method indicates that ATO particles B are ATO particles treated with a silane coupling agent. In addition, the silicon content in the above range indicates that the ATO particles B in the conductive dispersion are suitably treated with a silane coupling agent, which makes it easier to disperse the ATO particles B in the conductive dispersion and reduces the surface roughness of the coating film when it is formed into a coating film. The proportion of silicon element can be adjusted by changing the amount of silane coupling agent used in preparing ATO particles B.

[0037] The content of ATO particles B in the conductive dispersion is preferably 10 to 90 parts by mass, more preferably 20 to 80 parts by mass, and even more preferably 25 to 75 parts by mass, relative to 100 parts by mass of the total of ATO particles A and ATO particles B contained in the conductive dispersion. Within this range, the surface resistivity of the resin film tends to decrease, and the surface roughness tends to decrease. Furthermore, as the content of ATO particles B increases, the surface resistivity tends to increase, and the surface roughness tends to decrease. This is thought to be due to improved compatibility with the dispersion medium and improved dispersibility.

[0038] The cumulant average particle size of the ATO particles B in the conductive dispersion is preferably 1 to 1500 nm, more preferably 90 to 1000 nm, even more preferably 100 to 1000 nm, and particularly preferably 100 to 500 nm. The cumulant average particle size of the ATO particles B may be the same as or different from the average particle size of the ATO particles A. A specific method for measuring the cumulant average particle size of the ATO particles B will be described later.

[0039] The content of tin oxide particles in the conductive dispersion is not particularly limited, but may be 5.0 to 50.0 mass %, 10.0 to 45.0 mass %, or 20.0 to 50.0 mass %. The cumulant average particle size of tin oxide particles in the conductive dispersion is 90 to 400 nm. The average particle size is preferably 100 to 350 nm. Within the above range, a highly conductive film can be formed, while the dispersion liquid can improve the surface roughness of the film. A specific method for measuring the cumulant average particle size of tin oxide particles will be described later.

[0040] [Organic acid] The conductive dispersion liquid contains an organic acid. The organic acid is dissolved in the dispersion medium. The dispersibility of ATO particles in the conductive dispersion liquid is affected by the pH of the dispersion liquid. During the drying process of a paint using the conductive dispersion liquid, it is possible to control the aggregation of the ATO particles by controlling the pH of the coating film so that it approaches the isoelectric point of the ATO particles. To achieve this control, the conductive dispersion liquid contains an organic acid. By including an organic acid in the conductive dispersion liquid, the pH of the dispersion liquid can be set to a value closer to the isoelectric point of the ATO particles during the process of evaporating the dispersion medium from the conductive dispersion liquid. The organic acid is not particularly limited as long as it shifts the pH of the dispersion liquid to the acidic side during evaporation of the dispersion medium contained in the dispersion liquid. Examples of such organic acids that can be used include carboxylic acids such as acetic acid, malic acid, lactic acid, and succinic acid, and sulfonic acids. When the dispersion is mixed with a resin such as a (meth)acrylic resin or a urethane resin to form a coating material for forming a resin film, compatibility is improved by including an organic acid in the coating material. Furthermore, the organic acid is preferably a low-molecular-weight compound such as acetic acid or malic acid, and more preferably a weak acid. One type of organic acid may be used alone, or multiple types may be used in combination.

[0041] The content of the organic acid in the conductive dispersion liquid is preferably 0.10 to 5.00 parts by mass, more preferably 0.10 to 3.00 parts by mass, even more preferably 0.10 to 2.00 parts by mass, even more preferably 0.20 to 2.00 parts by mass, particularly preferably 0.40 to 2.00 parts by mass, and especially preferably 0.50 to 2.00 parts by mass, relative to 100 parts by mass of tin oxide particles. Within the above range, in the dispersion state, the pH of the conductive dispersion is far from the isoelectric point of the ATO particles, which tends to weaken the aggregation effect. Therefore, the steric repulsion of the tin oxide particles due to the amine compound described below prevails, making it easier to maintain a highly dispersed state of the tin oxide particles. Furthermore, during the process of evaporating the dispersion medium from the conductive dispersion, the pH tends to shift toward acidity. Accordingly, the zeta potential of the tin oxide particles in the dispersion also tends to shift toward 0 mV (the isoelectric point). As a result, the aggregation effect tends to prevail over the steric repulsion effect, making it easier to control the aggregation of the tin oxide particles and allowing the tin oxide particles to form conductive paths.

[0042] [Amine compounds] The conductive dispersion contains an amine compound. The amine compound is dissolved in a dispersion medium. The amine compound can increase the dispersion stability of ATO particles in the dispersion, so the conductive dispersion contains an amine compound and the amine compound is dissolved in a dispersion medium, thereby making it possible to extend the pot life of the conductive dispersion. In other words, the amine compound acts as a dispersant. There are no limitations as long as the amine compound is used, but at least one compound selected from the group consisting of secondary amines and tertiary amines represented by the following formula (1) is particularly preferred. [ka] In formula (1), R 1 and R 2 are each independently an aliphatic hydrocarbon group (preferably having 1 to 2 carbon atoms), R represents an alkyl group having 3 to 23 carbon atoms, more preferably 3 to 23 carbon atoms, still more preferably 6 to 23 carbon atoms, and particularly preferably 7 to 17 carbon atoms; 3 represents a hydrogen atom or an aliphatic hydrocarbon group (an alkyl group preferably having 1 to 23 carbon atoms, more preferably having 3 to 23 carbon atoms, still more preferably having 6 to 23 carbon atoms, and particularly preferably having 7 to 17 carbon atoms).

[0043] Such amine compounds are not particularly limited, and examples thereof include secondary amines such as diisopropylamine, di-n-propylamine, di-n-heptylamine, dicycloheptylamine, di-n-octylamine, dicyclooctylamine, di-n-nonylamine, di-n-decylamine, di-n-undecylamine, di-n-dodecylamine, di-n-tridecylamine, di-n-tetradecylamine, di-n-pentadecylamine, di-n-hexadecylamine, and di-n-heptadecylamine. Other examples include tertiary amines such as tri-n-butylamine, tri-n-pentylamine, tricyclopentylamine, tri-n-hexylamine, tricyclohexylamine, tri-n-heptylamine, tricycloheptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, tri-n-undecylamine, dimethyl-n-undecylamine, dimethyl-n-dodecylamine, dimethyl-n-tridecylamine, dimethyl-n-octadecylamine, dimethyl-n-hexadecylamine, dimethyl-n-heptadecylamine, and dimethyl-n-octadecylamine. The amine compound is preferably a tertiary amine. In particular, tri-n-octylamine, tri-n-butylamine, tri-n-hexylamine, dimethyl-n-octadecylamine, and tri-n-undecylamine are more likely to improve the dispersibility of ATO particles in the conductive dispersion and extend the pot life. The amine compound may be used alone or in combination of two or more kinds.

[0044] The reason why the inclusion of the amine compound improves the dispersion stability of ATO particles in the conductive dispersion is thought to be as follows: The amine compound is bonded to the surface of the ATO particles, and the aliphatic hydrocarbon groups of the amine compound cause steric repulsion (steric hindrance) between the ATO particles. The dispersion stabilization due to steric hindrance can be improved as the number of aliphatic hydrocarbon groups increases. Therefore, the amine compound is preferably at least one compound selected from the group consisting of secondary amines and tertiary amines.

[0045] Furthermore, the longer the aliphatic hydrocarbon group, the more likely dispersion stabilization due to steric hindrance occurs. Therefore, it is believed that the larger the molecular weight of the aliphatic hydrocarbon group, the more likely the stabilization tends to occur. Therefore, in order to more sufficiently stabilize the dispersion of ATO particles in the conductive dispersion, the molecular weight is preferably 100 or more, more preferably 150 or more, and even more preferably 180 or more. When the molecular weight of the amine compound is 100 or more, sufficient steric hindrance occurs in the conductive dispersion, making it easier to prevent aggregation and sedimentation of the ATO particles in the conductive dispersion. As a result, the surface roughness tends to be reduced. Furthermore, the pot life of the dispersion is improved.

[0046] Furthermore, when the molecular weight of the amine compound is 500 or less, the electrostatic cohesion force acting on the ATO particles due to the increase in pH in the coating film during the drying process of the coating material for forming a resin film can be more easily strengthened than the steric repulsion force of the amine compound. This promotes the formation of conductive paths by the ATO particles during the drying process of the coating film, making it easier for the resin film to exhibit conductivity. Furthermore, it prevents the aliphatic hydrocarbon groups of the amine compound from becoming too long, which would otherwise result in the surface of the ATO particles being covered with aliphatic hydrocarbon groups. As a result, the conductivity of the ATO particles themselves is less likely to decrease. This contributes to the formation of a conductive resin film. From the above, the molecular weight of the amine compound is preferably 180 to 500, particularly preferably 200 to 500, and further more preferably 250 to 450. preferable.

[0047] The content of the amine compound in the conductive dispersion is not particularly limited as long as it is within a range that exhibits the above-mentioned effects. However, it is preferably 0.05 to 5.00 parts by mass, more preferably 0.10 to 3.00 parts by mass, even more preferably 0.20 to 1.00 parts by mass, and particularly preferably 0.25 to 1.00 parts by mass, per 100 parts by mass of tin oxide particles. Within this range, the tin oxide particles are sufficiently stabilized for dispersion, and the aggregation effect prevails over the steric repulsion effect during the drying process of the coating film, making it easier to control the aggregation of the tin oxide particles and facilitate the formation of conductive paths by the tin oxide particles. In other words, this contributes to the formation of a conductive resin film. Furthermore, the dispersion is likely to have a pH higher than the isoelectric point of the tin oxide particles.

[0048] [Phosphorus compounds] The conductive dispersion contains a phosphorus compound. The phosphorus compound is dissolved in a dispersion medium. The phosphate group in the phosphorus compound is believed to adsorb more strongly to metal oxides than the aforementioned amine compounds, resulting in a higher dispersion effect. Therefore, the phosphorus compound adsorbs to the ATO particles, making them less susceptible to aggregation due to pH changes during the drying process. As a result, it is believed to have the effect of preventing excessive aggregation of the ATO particles. Therefore, when a coating film is formed using the conductive dispersion of the present disclosure, the ATO particles aggregate due to the effect of the organic acid, but the ATO particles to which the phosphorus compound has adsorbed maintain a repulsive effect. Therefore, it is believed that the state shown in Figure 1B is likely to form.

[0049] The molecular weight of the phosphorus compound is preferably 300 to 5,000. As with amine compounds, the larger the molecular weight of a phosphorus compound, the more improved the dispersion stabilization effect due to steric hindrance. On the other hand, in order to sufficiently suppress the aggregation of ATO particles during the drying process, it is more preferable that the molecular weight of the phosphorus compound is equal to or greater than the molecular weight of the amine compound. This prevents aggregation of ATO particles and makes it easier to disperse them more stably. On the other hand, if the molecular weight is too large, compatibility with the dispersion medium may decrease. Therefore, the molecular weight of the phosphorus compound is preferably 300 to 5,000, more preferably 500 to 5,000, and particularly preferably 800 to 2,000.

[0050] The phosphorus compound is preferably at least one compound selected from the group consisting of diesters and triesters represented by the following formula (2), and more preferably a diester represented by the following formula (2). [ka] In formula (2), R 4 ~R 6 represents a hydrogen atom or an organic group, and R 4 ~R 6 At least two selected from the group consisting of: represent an organic group.

[0051] The organic group is not particularly limited, but may be a monovalent organic group, or may have a divalent linking group between the monovalent organic group and the oxygen atom adjacent to the phosphorus atom. Examples of the monovalent organic group include a hydrocarbon group and an amino group. Examples of the hydrocarbon group include an aliphatic hydrocarbon group and an aromatic hydrocarbon group, and specific examples include an alkyl group, a vinyl group, a phenyl group, and an alkylphenyl group. The hydrocarbon group may be linear or branched. The hydrocarbon group may be unsubstituted or may have any functional group. The number of carbon atoms in the hydrocarbon group is not particularly limited, but may be, for example, 2 to 50, or 3 to 20.

[0052] As the divalent linking group, known linking groups can be used, such as alkylene groups, ether groups, ester groups, and amine groups. The alkylene group may be linear, branched, or cyclic. The alkylene group may be unsubstituted or may have any functional group. In addition, the alkylene group may have a plurality of divalent linking groups. The number of carbon atoms in the alkylene group is not particularly limited, but may be, for example, 1 to 50, and preferably 3 to 20.

[0053] Such phosphorus compounds can be generally commercially available, and examples thereof include DA325 and DA375 manufactured by Kusumoto Chemical Industries, Ltd., the Phosphanol series manufactured by Toho Chemical Industry Co., Ltd., JP-502, JP-504, and JP-506H manufactured by Johoku Chemical Co., Ltd., and DISPERBYK-111 manufactured by BYK Chemical Industry Co., Ltd.

[0054] The diesters and triesters represented by the above formula (2) can improve compatibility with hydrophobic dispersion media such as methyl ethyl ketone (MEK) and methyl isobutyl ketone (MIBK) due to the action of organic groups such as alkyl groups, ether groups, ester groups, and amine groups bonded to the phosphate groups, and therefore function well as dispersants for inorganic particles.

[0055] The content of the phosphorus compound in the conductive dispersion is not particularly limited as long as it is within a range in which the above-mentioned effects are exhibited, but is preferably 0.25 to 10.00 parts by mass, more preferably 0.50 to 10.00 parts by mass, even more preferably 0.50 to 5.00 parts by mass, particularly preferably 1.00 to 5.00 parts by mass, and even more preferably 1.25 to 5.00 parts by mass, relative to 100 parts by mass of tin oxide particles.

[0056] [Dispersion medium] The conductive dispersion liquid contains a dispersion medium. The dispersion medium is not particularly limited as long as it is one generally used in coating paints, but an organic solvent is preferred. For example, aliphatic alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, and isobutyl alcohol, aromatic alcohols such as benzyl alcohol, and ketones such as methyl isobutyl ketone, methyl ethyl ketone, diisobutyl ketone, and cyclohexanone can be used. These organic solvents may be used alone or in combination of two or more. Furthermore, it is preferable to include a volatile organic solvent such as isopropyl alcohol or methyl ethyl ketone in the dispersion medium, since this makes it easier to increase the pH of the coating film, even when the coating film of the resin film-forming paint is dried at room temperature, such as 23°C. The content of the dispersion medium in the conductive dispersion liquid is not particularly limited and may be set appropriately depending on the viscosity of the conductive dispersion liquid, etc., but is preferably 20 to 90 mass %, more preferably 30 to 90 mass %.

[0057] [Polydispersity index] The polydispersity index of the tin oxide particles in the conductive dispersion is not particularly limited, but a small value is preferable. A small polydispersity index indicates a narrow particle size distribution, i.e., a state close to monodispersion. The polydispersity index is preferably 0.500 or less, more preferably 0.400 or less, and even more preferably 0.360 or less. There is no particular lower limit, and 0. The polydispersity index may be 0.000 to 0.500, 0.000 to 0.400, or 0.000 to 0.360. The polydispersity index value can be made small by highly dispersing the tin oxide particles. The method for measuring the polydispersity index value will be described later.

[0058] [Paint for forming resin film] A paint for forming a resin film according to at least one embodiment of the present disclosure is a paint for forming a resin film containing a resin, and includes at least one selected from the group consisting of the resin and a precursor of the resin, tin oxide particles, an organic acid, a phosphorus compound, and an amine compound, wherein the tin oxide particles include antimony-containing tin oxide particles A that have not been treated with a silane coupling agent, and antimony-containing tin oxide particles B that have been treated with a silane coupling agent. In this configuration, the organic acid, phosphorus compound, and amine compound are dissolved in the paint. This type of paint for forming a resin film makes it possible to stably form a resin film with high conductivity and small surface roughness, which is thought to be due to the presumed mechanism explained above. The antimony-containing tin oxide particles A that have not been treated with a silane coupling agent, the antimony-containing tin oxide particles B that have been treated with a silane coupling agent, the organic acid, the phosphorus compound, and the amine compound can be those described in the respective columns above.

[0059] The coating material for forming a resin film contains at least one selected from the group consisting of a resin and a precursor of the resin. The resin is not particularly limited, and examples thereof include thermoplastic resins, thermosetting resins, and ionizing radiation curable resins. Examples of ionizing radiation curable resins include resins that can be cured with ultraviolet rays or electron beams, such as ultraviolet curable resins and electron beam curable resins, and include (meth)acrylic resins. (Meth)acrylic resins are a general term for acrylic resins and methacrylic resins.

[0060] The resin precursor is not particularly limited, and for example, a monomer, oligomer, or polymer of a thermosetting resin or an ionizing radiation curable resin can be used as the resin precursor. When a resin precursor is used, for example, a polymerization initiator such as a photopolymerization initiator can be included in the coating material for forming the resin film, and the resin precursor can be polymerized and cured by heat, ultraviolet light, electron beams, or the like to form a resin. For example, precursors of (meth)acrylic resins include monomers and oligomers that can form (meth)acrylic resins. The monomers and oligomers are not particularly limited, and known ones can be used. The content of at least one selected from the group consisting of resins and precursors of said resins in the coating material for forming a resin film is not particularly limited, but is preferably 5.0 to 30.0 mass %, more preferably 5.0 to 20.0 mass %.

[0061] The (meth)acrylic resin is preferably at least one polymer selected from the group consisting of pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, alkyl(meth)acrylate, benzyl(meth)acrylate, phenyl(meth)acrylate, ethylene glycol di(meth)acrylate, and bisphenol A di(meth)acrylate. The (meth)acrylic resin is more preferably at least one polymer selected from the group consisting of pentaerythritol tri(meth)acrylate and pentaerythritol tetra(meth)acrylate, and further preferably a polymer of pentaerythritol triacrylate and pentaerythritol tetraacrylate.

[0062] Thermosetting resins include urethane resin, melamine resin, phenolic resin, unsaturated polypropylene, and the like. Examples of the thermoplastic resin include polyamide resin, polyimide resin, polyvinyl chloride resin, etc. As the resin, one of the above-mentioned resins may be used alone, or two or more types may be used in combination.

[0063] The solids concentration of the coating material for forming a resin film may be appropriately determined taking into consideration factors such as ease of application, the film thickness and conductivity of the resulting coating film. For example, the content of tin oxide particles in the coating material for forming a resin film can be 3.0 to 50.0 parts by mass, preferably 3.0 to 40.0 parts by mass, and more preferably 3.0 to 35.0 parts by mass, per 100 parts by mass of at least one polymer selected from the group consisting of resins and precursors of the resins. It may also be 24.0 to 50.0 parts by mass, preferably 24.0 to 40.0 parts by mass, and more preferably 24.0 to 35.0 parts by mass. The above ranges are preferred because they allow the content of tin oxide particles in the resin film to be reduced, allowing the resin film to maintain transparency while imparting excellent conductivity.

[0064] The coating material for forming a resin film may contain an organic solvent. The organic solvent that the coating material for forming a resin film may contain may be an organic solvent that can dissolve at least a part of the resin or at least a part of the precursor of the resin. For example, the organic solvents listed in the above-mentioned dispersion medium section may be used. Furthermore, other additives may be added to the coating material for forming the resin film as needed, provided that the effects of the present disclosure are not impaired. For example, curing initiators, leveling agents, antifoaming agents, lubricants, and other organic and inorganic compounds may be added.

[0065] The method for producing a coating material for forming a resin film can be carried out using a known stirring method. For example, the coating material can be produced by a mixing step in which the dispersion according to the present disclosure is mixed with at least one selected from the group consisting of a resin and a precursor of the resin, and, if necessary, other organic solvents, other additives, etc., and a homogenization step in which the mixture obtained in the mixing step is uniformly mixed using a dispersing device such as a mechanical stirrer or a paint shaker that shakes the coating material at high speed.

[0066] [Resin film containing ATO particles] The resin film includes a cured product of the resin film-forming coating material of the present disclosure. Specifically, the resin film-forming coating material is uniformly coated on the surface of a substrate using a known film-forming method, such as gravure coating, wire bar coating, spray coating, dip coating, or slit coating, to form a coating film. This coating film is dried, and if necessary, a curing treatment of the resin precursor is performed to harden the coating film into a resin film. Examples of drying and necessary curing treatments include heating and ultraviolet irradiation. As described above, the dispersion according to the present disclosure can form a resin film with excellent conductivity and low surface roughness. Therefore, the resin film according to the present disclosure can be suitably used for conductive resin films that particularly require surface smoothness. Specifically, the resin film according to the present disclosure can be suitably used for applications such as the surface layer of an intermediate transfer belt, which is an electrophotographic member that slides against other members, and a conductive optical film that requires suppression of surface scattering of light.

[0067] The thickness of the resin film is not particularly limited, but may be, for example, 1.00 to 5.00 μm, or 1.50 to 4.00 μm. The method for measuring the thickness of the resin film will be described later. The value of the arithmetic mean height Sa of the resin film is not particularly limited, but is preferably a small value. For example, it is preferably 0.0200 μm or less, more preferably 0.0100 μm or less, even more preferably 0.0050 μm or less, and particularly preferably 0.0042 μm or less. The lower limit is not particularly limited, and may be 0.0000 to 0.0200 μm, 0.0000 to 0.0100 μm, 0.0000 to 0.0050 μm, 0.000 The arithmetic mean height Sa may be 0 to 0.0042 μm. The method for measuring the arithmetic mean height Sa will be described later. The surface resistivity value of the resin film is not particularly limited, but a small value is preferable. For example, it is preferably 11.00 LOG Ω / □ or less, more preferably 10.50 LOG Ω / □ or less, and even more preferably 10.20 LOG Ω / □ or less. The lower limit is not particularly limited, and may be 5.00 to 11.00 LOG Ω / □, 5.00 to 10.50 LOG Ω / □, or 5.00 to 10.20 LOG Ω / □. The method for measuring surface resistivity will be described later.

[0068] [Component] The member of the present disclosure is a member having a substrate and a resin film on the surface of the substrate, wherein the coating film comprises a cured product of the coating material for forming a resin film of the present disclosure. By forming such a member, a member having excellent electrical conductivity and a surface with low roughness can be obtained.

[0069] The material used for the substrate is not particularly limited, but plastic, glass, metal, ceramic, etc. can be used.

[0070] [Electrophotographic materials] The use of the member is not particularly limited. For example, it is suitably used as an electrophotographic member such as an intermediate transfer member that temporarily transfers and holds a toner image, or a transport / transfer belt that sandwiches and transports a recording material as a transfer material. That is, the member is preferably an electrophotographic member. For example, the electrophotographic member is an electrophotographic belt. The electrophotographic member can be particularly suitably used as an intermediate transfer member. That is, the electrophotographic member is preferably an intermediate transfer member. The electrophotographic member may have an endless shape.

[0071] [Electrophotographic image forming device] 2 shows an example of an image forming apparatus that includes a member according to at least one embodiment of the present disclosure as an intermediate transfer member and is configured as an electrophotographic apparatus, i.e., a schematic cross-sectional view showing an example of an electrophotographic image forming apparatus. This image forming device forms color images on a recording medium S, such as paper, supplied from a paper feed cassette 20 using four colors of toner, represented by cyan (C), magenta (M), yellow (Y), and black (K), and image forming stations for each color are arranged side by side in an approximately horizontal direction. These image forming stations are provided with photosensitive drums 1c, 1m, 1y, and 1k, respectively. Here, the suffix "c," "m," "y," or "k" is added to the reference numeral to indicate which color image forming station the reference numeral belongs to. The electrophotographic image forming apparatus is provided with a laser scanner 3, which is a laser optical unit, from which laser beams 3c, 3m, 3y, and 3k corresponding to image signals for each color are emitted toward the photosensitive drums 1c, 1m, 1y, and 1k, respectively. Since all the image forming stations have the same structure, the image forming station for K color will be described here.

[0072] Surrounding the photosensitive drum 1k are arranged a conductive roller 2k which is a contact charging device, a developing unit 4k, a conductive roller 8k which is a primary transfer roller, and a toner recovery blade 14k which is used to clean the photosensitive drum 1k. The developing unit 4k is provided with a developing roller 41k which is a developer carrier that develops the latent image on the photosensitive drum 1k, a developing container 42k which holds toner supplied to the developing roller 41k, and a developing blade 43k which regulates the amount of toner on the developing roller 41k and applies an electric charge.

[0073] The electrophotographic belt 5 is configured as an endless belt. The electrophotographic belt 5 is provided in common to the image forming stations of each color, and is used for secondary transfer. The electrophotographic belt 5 is stretched over a direction roller 92, a tension roller 6, and a drive roller 7, and is rotated by the drive roller 7 in the direction of the arrow in the drawing. The electrophotographic belt 5 contacts the surfaces of the photosensitive drums 1c, 1m, 1y, and 1k in succession in the section between the tension roller 6 and the drive roller 7, and is pressed toward the photosensitive drums 1c, 1m, 1y, and 1k by primary transfer rollers 8c, 8m, 8y, and 8k, respectively. As a result, the toner images formed on the surfaces of the photosensitive drums 1c, 1m, 1y, and 1k are transferred to the surface of the electrophotographic belt 5, which serves as an intermediate transfer body. The density of the toner image transferred onto the intermediate transfer belt is detected by an image density sensor 160, and adjustments such as image misalignment are made as appropriate based on the detection results.

[0074] A secondary transfer roller 9 is provided opposite the secondary transfer opposing roller 92, and the electrophotographic belt 5 is pressed against the secondary transfer opposing roller 92 by the secondary transfer roller 9. A secondary transfer voltage is applied to the secondary transfer roller 9 from a power source via a current detection circuit 10. The secondary transfer roller 9 and the secondary transfer opposing roller 92 form a secondary transfer unit. The recording medium S passes through the nip between the electrophotographic belt 5 and the secondary transfer roller 9 at the position of the secondary transfer opposing roller 92 via a feed roller 12 and a transport roller 13, and the toner image held on the outer peripheral surface of the electrophotographic belt 5 is transferred thereto. As a result, an image is formed on the surface of the recording medium S.

[0075] The recording medium S onto which the toner image has been transferred passes through a fixing device 15 consisting of a pair of rollers, a heating roller 151 and a pressure roller 152, whereby the image is fixed, and the recording medium S is discharged onto a paper discharge tray 21. A cleaning blade 31 that comes into contact with the outer peripheral surface of the electrophotographic belt 5 is provided at the position of the tension roller 6. Toner that has not been transferred to the recording medium S and remains on the outer peripheral surface of the electrophotographic belt 5 is removed from the electrophotographic belt 5 by a belt cleaning device 30 and collected. [Example]

[0076] Hereinafter, the present disclosure will be described in more detail using examples. Aspects of the present disclosure are not limited to the following examples.

[0077] First, a method for evaluating the physical properties of a dispersion liquid, a paint for forming a resin film, and a resin film including a cured product of a coating film of the paint for forming a resin film will be described. <Average particle diameter of ATO particles> The average particle diameter of ATO particles in the dispersion liquid was measured using a particle size distribution meter (multi-sample nanoparticle size measurement system nanoSAQLA, manufactured by Otsuka Electronics Co., Ltd.) that calculates the average particle diameter by the dynamic light scattering method. The measurement was performed using the dispersion liquid as it was without dilution, using an AS cell, with an integration count of 50 times and a temperature of 25.0 °C. As measurement conditions, the refractive index and viscosity were set according to the dispersion medium used. For example, when the dispersion medium was methyl ethyl ketone, the refractive index was set to 1.364 and the viscosity to 0.421 mPa·s, and when the dispersion medium was isopropyl alcohol, the refractive index was set to 1.3813 and the viscosity to 2.0335 mPa·s.

[0078] Also, when the dispersion medium was a mixed solvent, the refractive index and viscosity were set from the type and ratio of each dispersion medium. For example, when the dispersion medium was a mixed solvent of methyl ethyl ketone and isopropyl alcohol, with the mass ratio of methyl ethyl ketone in the mixed solvent being x1 (mass %) and the mass ratio of isopropyl alcohol being x2 (mass %), the refractive index of the mixed solvent was determined using the following formula (A). The viscosity was calculated in the same manner. 1.364 × x1 / 100 + 1.3813 × x2 / 100 (A)

[0079] For the analysis of the average particle diameter, the cumulant method is used for calculation. Specifically, it can be obtained by the cumulant method from the autocorrelation function obtained by the photon correlation method. Also, the polydispersity index (PDI), which represents the width of the particle size distribution, was also measured using the same apparatus. Generally, the smaller the value of the PDI, the narrower the particle size distribution and the closer it is to monodispersity, and when it exceeds 0.5, it indicates that the analysis of the measurement results is difficult. The polydispersity index (PDI) was also measured using the same apparatus. The PDI generally indicates that the smaller the value, the narrower the particle size distribution and the closer it is to monodispersity, and when it exceeds 0.5, it represents that the analysis of the measurement results is difficult.

[0080] <Surface resistivity of the resin film> The surface resistivity of the resin film was measured in accordance with Japanese Industrial Standards (JIS) K 6911 using a resistivity meter (product name: Hiresta UP MCP-HT450, manufactured by Mitsubishi Chemical Analytech Co., Ltd.). A PEN film having a resin film on its surface, prepared by the method described below, was used to measure the surface resistivity of the resin film. The surface resistivity of the resin film was measured by applying a UR100 probe to the resin film on the surface of the PEN film under an environment of 23°C and 50% relative humidity, and the measured value was calculated at an applied voltage of 100V for a measurement time of 10 seconds.

[0081] <Surface roughness of resin film> The surface roughness of the resin film was evaluated by the arithmetic mean height Sa of the resin film. Measurements were made using a scanning white light interference microscope (product name: Vert Scan, manufactured by Ryoka Systems Co., Ltd.) as the measuring device. Observation was performed with a 5x objective lens, and the obtained image was subjected to fourth-order curve correction to remove waviness, after which Sa was calculated from the corrected image.

[0082] <Resin film thickness> The thickness of the resin film was measured using the following procedure. A cross section of the resin film was taken using an ion milling device (device name: IM4000, manufactured by Hitachi High-Technologies Corporation), and the cross section was observed using a scanning electron microscope (device name: JSM-F100, manufactured by JEOL Ltd.) to measure the thickness of the resin film. In Examples 1 to 11 and Comparative Examples 1 to 5, the cross section of the resin film was taken from the center of each PEN film. In Example 12 and Comparative Examples 6 and 7, the cross section of the resin film was taken from four locations on each intermediate transfer belt. At this time, the four locations were positioned at equal intervals to avoid arbitrariness. Specifically, the four locations were located at the center of the width direction of the intermediate transfer belt, at four locations every 90° in the circumferential direction.

[0083] Next, the preparation method of the conductive dispersion in the examples will be described in detail. In the examples, the conductive dispersion is prepared by separately preparing dispersion A using ATO particles A that have not been treated with a silane coupling agent, and dispersion B using ATO particles B that have been treated with a silane coupling agent, and then mixing these in an arbitrary ratio. Hereinafter, examples of preparing dispersion A and dispersion B will be described.

[0084] (Preparation of Dispersion A-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 (organic acid, manufactured by Kishida Chemical Co., Ltd.), 0.03 g of trioctylamine (amine compound, manufactured by Kishida Chemical Co., Ltd.), and 48.0 g of isopropyl alcohol (solvent, manufactured by Kishida Chemical Co., Ltd.) were weighed and placed in a 250 mL zirconia container. 108.3 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.). The beads were then removed by mesh filtration to obtain dispersion A-1, which had a solids concentration of ATO particles (i.e., the content of ATO particles in the dispersion) of 20% by mass. The average particle size of the ATO particles contained in this dispersion A-1 was measured to be 167.5 nm, and the polydispersity index was 0.281.

[0085] (Preparation of Dispersion A-2) Dispersion A was prepared except that the amine compound was changed to diisopropylamine (manufactured by Tokyo Chemical Industry Co., Ltd., molecular weight: 101.2) and the amount of the amine compound was changed to the content shown in Table 1. Dispersion A-2 was obtained in the same manner as in Dispersion A-1. The average particle size of the ATO particles contained in Dispersion A-2 was measured to be 348.1 nm, and the polydispersity index was 0.391.

[0086] (Preparation of Dispersion A-3) Dispersion A-3 was obtained in the same manner as Dispersion A-1, except that the amine compound was changed to tri-n-butylamine (manufactured by Tokyo Chemical Industry Co., Ltd., molecular weight: 185.4) and the amount of the amine compound was changed so as to obtain the content shown in Table 1. The average particle size of the ATO particles contained in this Dispersion A-3 was measured to be 274.7 nm, and the polydispersity index was 0.358.

[0087] (Preparation of Dispersion A-4) Dispersion A-4 was obtained in the same manner as Dispersion A-1, except that the amine compound was changed to tri-n-undecylamine (manufactured by Tokyo Chemical Industry Co., Ltd., molecular weight: 479.9) and the amount of the amine compound was changed so as to obtain the content shown in Table 1. The average particle size of the ATO particles contained in this Dispersion A-4 was measured to be 142.7 nm, and the polydispersity index was 0.266.

[0088] (Preparation of Dispersion A-5) Dispersion A-5 was obtained in the same manner as Dispersion A-1, except that no organic acid was used. The average particle size of the ATO particles contained in Dispersion A-5 was measured to be 247.4 nm, and the polydispersity index was 0.332.

[0089] (Preparation of Dispersion A-6) Dispersion A-6 was obtained in the same manner as Dispersion A-1, except that no amine compound was used. The average particle size of the ATO particles contained in Dispersion A-6 was measured to be 2296.9 nm, and the polydispersity index was 1.505.

[0090] (Preparation of Dispersion B-1) 100 g of antimony-containing tin oxide particles (product name: SN-100P, manufactured by Ishihara Sangyo Kaisha, Ltd.) were placed in a Henschel mixer, and 3.79 g of trimethoxymethylsilane (product name: KBM-13, manufactured by Shin-Etsu Silicones Co., Ltd.) was added dropwise while rotating the mixer at 80 rpm under room temperature and humidity conditions, followed by stirring for 2 hours. The resulting powder was then removed and heated and dried in a drying oven at 100°C for 1 hour to obtain ATO particles with a surface treatment rate of 30% by mass.

[0091] 12.50 g of ATO particles with a surface treatment rate of 30% by mass, 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, Fritsch Japan Co., Ltd.). 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 40% by mass. The average particle size of the ATO particles contained in this dispersion B-1 was measured to be 299.1 nm, and the polydispersity index was 0.305.

[0092] (Preparation of Dispersion B-2) ATO particles with a surface treatment rate of 10 mass % were obtained in the same manner as described in the preparation of dispersion B-1, except that the amount of trimethoxymethylsilane was changed to 1.26 g. Dispersion B-2 was obtained in the same manner as described in the preparation of dispersion B-1, except that the ATO particles with a surface treatment rate of 30% by mass were changed to ATO particles with a surface treatment rate of 10% by mass. The solid content concentration of the ATO particles in this dispersion B-2 was 40% by mass. The average particle size of the ATO particles contained in this dispersion B-2 was measured to be 347.3 nm, and the polydispersity index was 0.327.

[0093] (Preparation of Dispersion B-3) ATO particles with a surface treatment rate of 50 mass % were obtained in the same manner as described in the preparation of dispersion B-1, except that the amount of trimethoxymethylsilane was changed to 6.31 g. Dispersion B-3 was obtained in the same manner as in the preparation of Dispersion B-1, except that the ATO particles with a surface treatment rate of 30% by mass were replaced with ATO particles with a surface treatment rate of 50% by mass. The solids concentration of the ATO particles in Dispersion B-3 was 40% by mass. The average particle size of the ATO particles contained in this dispersion B-3 was measured to be 96.7 nm, and the polydispersity index was 0.285.

[0094] (Preparation of Dispersion B-4) Dispersion B-4 was obtained in the same manner as Dispersion B-1, except that the amine compound was changed to diisopropylamine (manufactured by Tokyo Chemical Industry Co., Ltd., molecular weight: 101.2) and the amount of the amine compound was changed so as to obtain the content shown in Table 2. The average particle size of the ATO particles contained in this Dispersion B-4 was measured to be 457.1 nm, and the polydispersity index was 0.353.

[0095] (Preparation of Dispersion B-5) Dispersion B-5 was obtained in the same manner as Dispersion B-1, except that the amine compound was changed to tri-n-butylamine (manufactured by Tokyo Chemical Industry Co., Ltd., molecular weight: 185.4) and the amount of the amine compound was changed so as to obtain the content shown in Table 2. The average particle size of the ATO particles contained in this Dispersion B-5 was measured to be 378.0 nm, and the polydispersity index was 0.338.

[0096] (Preparation of Dispersion B-6) Dispersion B-6 was obtained in the same manner as Dispersion B-1, except that the amine compound was changed to tri-n-undecylamine (manufactured by Tokyo Chemical Industry Co., Ltd., molecular weight: 479.9) and the amount of the amine compound was changed so as to obtain the content shown in Table 2. The average particle size of the ATO particles contained in this Dispersion B-6 was measured to be 242.9 nm, and the polydispersity index was 0.301.

[0097] (Preparation of Dispersion B-7) Dispersion B-7 was obtained in the same manner as Dispersion B-1, except that the phosphorus compound was changed to tris(2-butoxyethyl) phosphate (manufactured by Tokyo Chemical Industry Co., Ltd., molecular weight: 398.48) and the amounts of the phosphorus compound and the amine compound were changed so as to obtain the contents shown in Table 2. The average particle size of the ATO particles contained in Dispersion B-7 was measured to be 497.1 nm, and the polydispersity index was 0.362.

[0098] (Preparation of Dispersion B-8) Dispersion B-8 was obtained in the same manner as Dispersion B-1, except that no amine compound was used. An attempt was made to measure the average particle size of the ATO particles contained in this Dispersion B-8, but the particles were severely aggregated, exceeding the limit of particle size measurement, making it impossible to measure.

[0099] (Preparation of Dispersion B-9) Dispersion B-9 was obtained in the same manner as Dispersion B-1, except that no phosphorus compound was used and the amount of the amine compound was changed to the content shown in Table 2. The average particle size of the ATO particles contained in Dispersion B-9 was measured to be 5352.8 nm, and the polydispersity index was 0.917.

[0100] Table 1 shows the material types and contents of dispersions A-1 to A-6, and the physical properties of dispersion A. Table 2 also shows the material types and contents of dispersions B-1 to B-9, and the physical properties of dispersion B. [Table 1] In Table 1, ATO particles A are antimony-containing tin oxide that has not been treated with a silane coupling agent, TOA is tri-n-octylamine (manufactured by Kishida Chemical Co., Ltd.), DIA is diisopropylamine (manufactured by Kishida Chemical Co., Ltd.), TBA is tri-n-butylamine (manufactured by Kishida Chemical Co., Ltd.), TUA is tri-n-undecylamine (manufactured by Tokyo Chemical Industry Co., Ltd.), and IPA is isopropyl alcohol; the content indicates the content (parts by mass) relative to 100 parts by mass of the dispersion; and the particle size indicates the cumulant average particle size (nm). [Table 2] In Table 2, ATO particle B is antimony-containing tin oxide that has been subjected to silane coupling treatment, TOA is tri-n-octylamine (Kishida Chemical Co., Ltd.), and DIA is diisopropylamine. TBA denotes tri-n-butylamine (manufactured by Kishida Chemical Co., Ltd.), TUA denotes tri-n-undecylamine (manufactured by Tokyo Chemical Industry Co., Ltd.), and MEK denotes methyl ethyl ketone. The content indicates the content (parts by mass) relative to 100 parts by mass of the dispersion, and the particle size indicates the cumulant average particle size (nm).

[0101] [Example 1] (Preparation of Dispersion 1) 37.5 g of Dispersion A-1 was weighed out, and while stirring Dispersion A-1 using a magnetic stirrer, 6.25 g of Dispersion B-1 was added dropwise. Stirring was then carried out for 30 minutes to obtain Dispersion 1. Dispersion 1 had an ATO concentration of 22.9 mass%, a content of ATO particles A in the tin oxide particles of 25 mass%, and a content of ATO particles B in the tin oxide particles of 75 mass%. The average particle size of the tin oxide particles in Dispersion 1 was measured to be 222.0 nm, and the polydispersity index was 0.315.

[0102] (Preparation of a coating material for forming a resin film containing dispersion liquid 1) 2.152 g of dispersion 1 was weighed out, and 2.013 g of pentaerythritol and tetraacrylate (trade name: Aronix M-306, manufactured by Toa Gosei Co., Ltd.), 0.15 g of photopolymerization initiator (trade name: Omnirad 907, manufactured by IGM Resins), 0.004 g of leveling agent (trade name: Cymac US-270, manufactured by Toa Gosei Co., Ltd.), and 1.216 g of methyl ethyl ketone (manufactured by Kishida Chemical Co., Ltd.) were mixed with this dispersion 1 and stirred to obtain resin film-forming paint 1. The ATO concentration in paint 1 was 24.6 parts by mass per 100 parts by mass of binder resin. In this disclosure, pentaerythritol tri- and tetraacrylate refers to a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate.

[0103] (Preparation of resin film containing cured product of coating film of coating material 1 for forming resin film) The resin film-forming paint 1 was applied to a PEN film (Teonex Q51, manufactured by Toyobo Co., Ltd.) by bar coating using a No. 16 wire bar. The film was then dried for 1 minute in an exhausted environment at 23°C. The coating was then 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 resin film 1 was cured, thereby producing a PEN film 1 having a resin film 1 on the surface. The surface resistivity of the obtained PEN film 1 was measured and found to be 9.41 (LOGΩ / □), the surface roughness was 0.0042 μm, and the thickness of the resin film was 2.81 μm.

[0104] [Example 2] (Preparation of Dispersion 2) 25.00 g of Dispersion A-1 was weighed out, and 12.50 g of Dispersion B-1 was added dropwise to Dispersion A-1 while stirring using a magnetic stirrer. Stirring was then continued for 30 minutes to obtain Dispersion 2. Dispersion 2 had an ATO concentration of 26.7% by mass, a content of ATO particles A in the tin oxide particles of 50% by mass, and a content of ATO particles B in the tin oxide particles of 50% by mass. The average particle size of the tin oxide particles in Dispersion 2 was measured to be 162.5 nm, and the polydispersity index was 0.290.

[0105] (Preparation of a coating material for forming a resin film containing dispersion liquid 2) Coating material 2 for forming a resin film was obtained in the same manner as in Example 1, except that dispersion 1 was changed to 1.833 g of dispersion 2 and the amount of methyl ethyl ketone was changed to 1.527 g. ATO concentration of coating material 2 is 24.6 parts by mass relative to 100 parts by mass of the binder resin.

[0106] (Preparation of resin film containing cured product of coating film of paint 2 for forming resin film) A PEN film 2 having a resin film 2 on its surface was produced in the same manner as in Example 1, except that a resin film-forming coating material 2 was used. The surface resistivity of the obtained PEN film 2 was measured and found to be 10.04 (LOGΩ / □), the surface roughness was 0.0035 μm, and the thickness of the resin film was 2.98 μm.

[0107] [Example 3] (Preparation of Dispersion 3) 12.5 g of Dispersion A-1 was weighed out, and 21.0 g of Dispersion B-1 was added dropwise to Dispersion A-1 while stirring using a magnetic stirrer. Stirring was then continued for 30 minutes to obtain Dispersion 3. Dispersion 3 had an ATO concentration of 32.5 mass%, a content of ATO particles A in the tin oxide particles of 25 mass%, and a content of ATO particles B in the tin oxide particles of 75 mass%. The average particle size of the tin oxide particles in Dispersion 3 was measured to be 239.9 nm, and the polydispersity index was 0.278.

[0108] (Preparation of a coating material for forming a resin film containing dispersion 3) Coating material 3 for forming a resin film was obtained in the same manner as in Example 1, except that dispersion 1 was changed to 1.650 g of dispersion 3 and the amount of methyl ethyl ketone was changed to 1.686 g. The ATO concentration in coating material 3 was 24.6 parts by mass per 100 parts by mass of the binder resin.

[0109] (Preparation of resin film containing cured product of coating film of coating material 3 for forming resin film) A PEN film 3 having a resin film 3 on its surface was produced in the same manner as in Example 1, except that a paint 3 for forming a resin film was used. The surface resistivity of the obtained PEN film 3 was measured and found to be 10.44 (LOGΩ / □), the surface roughness was 0.0023 μm, and the thickness of the resin film was 2.83 μm.

[0110] [Example 4] (Preparation of Dispersion 4) 25.0 g of Dispersion A-1 was weighed out, and 12.5 g of Dispersion B-2 was added dropwise to Dispersion A-1 while stirring using a magnetic stirrer. Stirring was then continued for 30 minutes to obtain Dispersion 4. Dispersion 4 had an ATO concentration of 26.7 mass%, a content of ATO particles A in the tin oxide particles of 50 mass%, and a content of ATO particles B in the tin oxide particles of 50 mass%. The average particle size of the tin oxide particles in Dispersion 4 was measured to be 295.6 nm, and the polydispersity index was 0.345.

[0111] (Preparation of a coating material for forming a resin film containing dispersion 4) Coating material 4 for forming a resin film was obtained in the same manner as in Example 2, except that dispersion 2 was changed to dispersion 4. The ATO concentration in coating material 4 was 24.6 parts by mass relative to 100 parts by mass of the binder resin.

[0112] (Preparation of resin film containing cured product of coating film of paint 4 for forming resin film) A PEN film 4 having a resin film 4 on its surface was produced in the same manner as in Example 1, except that a paint 4 for forming a resin film was used. The surface resistivity of the obtained PEN film 4 was measured and found to be 9.81 (LOGΩ / □), the surface roughness was 0.0037 μm, and the thickness of the resin film was 2.96 μm.

[0113] [Example 5] (Preparation of Dispersion 5) 25.0 g of Dispersion A-1 was weighed out, and 12.5 g of Dispersion B-3 was added dropwise to Dispersion A-1 while stirring using a magnetic stirrer. Stirring was then continued for 30 minutes to obtain Dispersion 5. Dispersion 5 had an ATO concentration of 26.7 mass%, a content of ATO particles A in the tin oxide particles of 50 mass%, and a content of ATO particles B in the tin oxide particles of 50 mass%. The average particle size of the tin oxide particles in Dispersion 5 was measured to be 97.9 nm, and the polydispersity index was 0.277.

[0114] (Preparation of a coating material for forming a resin film containing dispersion 5) Resin film-forming coating material 5 was obtained in the same manner as in Example 2, except that dispersion 2 was changed to dispersion 5. The ATO concentration in coating material 5 was 24.6 parts by mass relative to 100 parts by mass of the binder resin.

[0115] (Preparation of resin film containing cured product of coating film of coating material 5 for forming resin film) A PEN film 5 having a resin film 5 on its surface was produced in the same manner as in Example 1, except that a paint 5 for forming a resin film was used. The surface resistivity of the obtained PEN film 5 was measured and found to be 10.14 (LOGΩ / □), the surface roughness was 0.0029 μm, and the thickness of the resin film was 2.84 μm.

[0116] [Example 6] (Preparation of Dispersion 6) 25.0 g of Dispersion A-2 was weighed out, and 12.5 g of Dispersion B-4 was added dropwise to Dispersion A-2 while stirring using a magnetic stirrer. Stirring was then continued for 30 minutes to obtain Dispersion 6. Dispersion 6 had an ATO concentration of 26.7 mass%, a content of ATO particles A in the tin oxide particles of 50 mass%, and a content of ATO particles B in the tin oxide particles of 50 mass%. The average particle size of the tin oxide particles in Dispersion 6 was measured to be 363.1 nm, and the polydispersity index was 0.349.

[0117] (Preparation of a coating material for forming a resin film containing dispersion 6) Resin film-forming paint 6 was obtained in the same manner as in Example 2, except that dispersion 2 was changed to dispersion 6. The ATO concentration in paint 6 was 24.6 parts by mass relative to 100 parts by mass of the binder resin.

[0118] (Preparation of resin film containing cured product of coating film of paint 6 for forming resin film) A PEN film 6 having a resin film 6 on its surface was produced in the same manner as in Example 1, except that a paint 6 for forming a resin film was used. The surface resistivity of the obtained PEN film 6 was measured and found to be 9.76 (LOGΩ / □), the surface roughness was 0.0041 μm, and the thickness of the resin film was 2.65 μm.

[0119] [Example 7] (Preparation of Dispersion 7) 25.0 g of Dispersion A-3 was weighed out, and 12.5 g of Dispersion B-5 was added dropwise to Dispersion A-3 while stirring using a magnetic stirrer. Stirring was then continued for 30 minutes to obtain Dispersion 7. Dispersion 7 had an ATO concentration of 26.7% by mass, a content of ATO particles A in the tin oxide particles of 50% by mass, and a content of ATO particles B in the tin oxide particles of 50% by mass. The average particle size of the tin oxide particles in Dispersion 7 was measured to be 346.8 nm, and the polydispersity index was 0.286.

[0120] (Preparation of a coating material for forming a resin film containing dispersion liquid 7) Resin film-forming paint 7 was obtained in the same manner as in Example 2, except that dispersion 2 was changed to dispersion 7. The ATO concentration in paint 7 was 24.6 parts by mass relative to 100 parts by mass of the binder resin.

[0121] (Preparation of resin film containing cured product of coating film of paint 7 for forming resin film) A PEN film (Teonex Q51, manufactured by Toyobo Co., Ltd.) was coated with the resin film-forming paint 7 by bar coating using a No. 16 wire bar. The film was then dried for 1 minute in an exhausted environment at 23°C. The coating film was then irradiated with ultraviolet light using a UV irradiator (product name: UE06 / 81-3, manufactured by Eye Graphics Co., Ltd.) until the cumulative light dose reached 600 mJ / cm2, and the coating film was cured. A PEN film 7 having a resin film 7 on its surface was produced in the same manner as in Example 1, except that the coating film was then cured. The surface resistivity of the obtained PEN film 7 was measured and found to be 9.83 (LOGΩ / □), the surface roughness was 0.0037 μm, and the thickness of the resin film was 2.98 μm.

[0122] [Example 8] (Preparation of Dispersion 8) 25.0 g of Dispersion A-4 was weighed out, and 12.5 g of Dispersion B-6 was added dropwise to Dispersion A-4 while stirring using a magnetic stirrer. Stirring was then continued for 30 minutes to obtain Dispersion 8. Dispersion 8 had an ATO concentration of 26.7% by mass, a content of ATO particles A in the tin oxide particles of 50% by mass, and a content of ATO particles B in the tin oxide particles of 50% by mass. The average particle size of the tin oxide particles in Dispersion 8 was measured to be 212.8 nm, and the polydispersity index was 0.291.

[0123] (Preparation of a coating material for forming a resin film containing dispersion 8) Resin film-forming coating material 8 was obtained in the same manner as in Example 2, except that dispersion 2 was changed to dispersion 8. The ATO concentration in coating material 8 was 24.6 parts by mass relative to 100 parts by mass of the binder resin.

[0124] (Preparation of resin film containing cured product of coating film of paint 8 for forming resin film) A PEN film 8 having a resin film 8 on its surface was produced in the same manner as in Example 1, except that a paint 8 for forming a resin film was used. The surface resistivity of the obtained PEN film 8 was measured and found to be 10.16 (LOGΩ / □), the surface roughness was 0.0026 μm, and the thickness of the resin film was 2.96 μm.

[0125] [Example 9] (Preparation of Dispersion 9) 25.0 g of Dispersion A-1 was weighed out, and 12.5 g of Dispersion B-7 was added dropwise to Dispersion A-1 while stirring using a magnetic stirrer. Stirring was then continued for 30 minutes to obtain Dispersion 9. Dispersion 9 had an ATO concentration of 26.7 mass%, a content of ATO particles A in the tin oxide particles of 50 mass%, and a content of ATO particles B in the tin oxide particles of 50 mass%. The average particle size of the tin oxide particles in Dispersion 9 was measured to be 391.2 nm, and the polydispersity index was 0.335.

[0126] (Preparation of a coating material for forming a resin film containing dispersion 9) Resin film-forming coating material 9 was obtained in the same manner as in Example 2, except that dispersion 2 was changed to dispersion 9. The ATO concentration in coating material 9 was 24.6 parts by mass relative to 100 parts by mass of the binder resin.

[0127] (Preparation of resin film containing cured product of coating film of coating material 9 for forming resin film) A PEN film 9 having a resin film 9 on its surface was produced in the same manner as in Example 1, except that a paint 9 for forming a resin film was used. The surface resistivity of the obtained PEN film 9 was measured and found to be 9.23 (LOGΩ / □), the surface roughness was 0.0048 μm, and the thickness of the resin film was 2.86 μm.

[0128] [Example 10] (Preparation of a coating material for forming a resin film containing dispersion liquid 2) Except for changing the amount of dispersion 2 to 2.601 g and the amount of methyl ethyl ketone to 1.447 g, the same procedure as in Example 2 was carried out to obtain a resin film-forming coating material 10. The ATO concentration in coating material 10 was 35.0 parts by mass relative to the acrylic resin binder.

[0129] (Preparation of resin film containing cured product of coating film of coating material 10 for forming resin film) A PEN film 10 having a resin film 10 on its surface was produced in the same manner as in Example 1, except that a coating material 10 for forming a resin film was used. The surface resistivity of the obtained PEN film 10 was measured and found to be 9.16 (LOGΩ / □), the surface roughness was 0.0045 μm, and the thickness of the resin film was 2.86 μm.

[0130] [Example 11] (Preparation of a coating material for forming a resin film containing dispersion liquid 2) Except for changing the amount of dispersion 2 to 3.727 g and the amount of methyl ethyl ketone to 1.359 g, the same procedure as in Example 2 was carried out to obtain a resin film-forming coating material 11. The ATO concentration in coating material 11 was 50 parts by mass relative to the acrylic resin binder.

[0131] (Preparation of resin film containing cured product of coating film of coating material 11 for forming resin film) A PEN film 11 having a resin film 11 on its surface was produced in the same manner as in Example 1, except that a paint 11 for forming a resin film was used. The surface resistivity of the obtained PEN film 11 was measured and found to be 8.62 (LOGΩ / □), the surface roughness was 0.0049 μm, and the thickness of the resin film was 2.61 μm.

[0132] [Example 12] A method for producing an electrophotographic intermediate transfer belt using paint 2 will be described. (Preparation of surface paint) 64.53 g of dispersion liquid 2 was weighed out, and 259.1 g of a resin liquid composed of the following materials was mixed with this dispersion liquid 2 and stirred, thereby obtaining a surface layer coating material 1 for an intermediate transfer belt. The resin solution was prepared as follows: 88.83 g of pentaerythritol and tetraacrylate (trade name: Aronix M-305, manufactured by Toagosei Co., Ltd.), 6.75 g of a photopolymerization initiator (trade name: Omnirad907, manufactured by IGM Resins), and 1.0 g of a leveling agent (trade name: The following ingredients were weighed and mixed: 0.19 g of Cymac US-270 (manufactured by Toagosei Co., Ltd.), 62.2 g of methyl ethyl ketone (manufactured by Kishida Chemical Co., Ltd.), 14.4 g of polytetrafluoroethylene particles (PTFE) (Lubron L-2 (manufactured by Daikin Industries, Ltd.) as a lubricant), 3.50 g of a dispersant for PTFE particles (trade name: Aron GF-400 (manufactured by Toagosei Co., Ltd.)), and 119.2 g of methyl isobutyl ketone (MIBK). The resulting mixture was then roughly dispersed using a homogenizer, and the resulting solution was further dispersed using a high-pressure emulsifying disperser (trade name: Nanovaita (manufactured by Yoshida Kikai Kogyo Co., Ltd.) to prepare a resin solution.

[0133] (Formation of base layer of electrophotographic intermediate transfer belt) The following raw materials were used to form the base layer. Polyethylene naphthalate (trade name: Teonex TN8050SC, manufactured by Teijin Ltd.) (hereinafter referred to as "PE(1)") as a polyester resin. Conductive agent: polyether ester amide (product name: TPAE-10HP-10, manufactured by T&K TOKA Corporation) (hereinafter referred to as "PEEA"). Potassium perfluorobutanesulfonate (product name: F-Top KFBS, Mitsubishi Material (Manufactured by KFBS Co., Ltd.) (hereinafter referred to as "KFBS").

[0134] The above PE(1), PEEA, and KFBS were mixed at a ratio of PE(1) / PEEA / KFBS = 80 / 18 / 2 (mass%). The mixture was then melt-kneaded at 290°C for 5 minutes using a twin-screw extruder (trade name: TEX30α, manufactured by The Japan Steel Works, Ltd.) to obtain a resin mixture consisting of PE(1), PEEA, and KFBS. The resulting resin mixture was pelletized using a cutter (trade name: Fan Cutter, manufactured by Hoshi Plastics Co., Ltd.) to obtain resin mixture pellets (pellet size: major axis 3 mm × minor axis 2 mm). The resulting pellets were dried at 140°C for 6 hours. Next, the dried pellets of the resin mixture were placed in the hopper of an injection molding machine (product name: SE180D, manufactured by Sumitomo Heavy Industries, Ltd.). The cylinder temperature was set to 290°C, and the mixture was melted under screw agitation and injection-molded into a mold to produce a test-tube-shaped preform. The resulting preform was placed in a blow molding machine and blown into a blow mold maintained at a mold temperature of 110°C using a stretch rod and air at a preform temperature of 155°C, an air pressure of 0.3 MPa, and a stretch rod speed of 1000 mm / s to produce a blown bottle. Both ends of the blown bottle were cut to produce an endless belt-shaped base layer measuring 712 mm in the circumferential direction and 244 mm in the width perpendicular to the circumferential direction. The base layer had a thickness of 70 μm.

[0135] (Formation of surface layer) The base layer obtained by blow molding was fitted onto the outer periphery of a cylindrical mold, the edges were sealed, and the mold was then immersed in a container filled with the prepared surface layer coating 1. The mold was then 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 surface layer coating 1 on the surface of the base layer. The pulling speed (relative speed between the liquid surface of the curable composition and the base layer) and the solvent ratio of the surface coating can be adjusted depending on the desired film thickness.

[0136] In this example, the lifting speed was set to 10 to 50 mm / sec, and the thickness of the surface layer was adjusted to 3 μm. After the coating film was formed, it was dried for 1 minute in an exhausted environment at 23°C. The drying temperature and drying time were adjusted appropriately depending on the solvent type, solvent ratio, and film thickness. Thereafter, the coating film 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 surface became uniform, forming a surface layer. Thus, an endless electrophotographic intermediate transfer belt 1 was obtained. The surface resistivity of this intermediate transfer belt 1 was measured and found to be 9.94 (LOG Ω / □). The surface roughness was 0.0039 μm, and the thickness of the resin film was 3.11 μm.

[0137] [Comparative Example 1] (Preparation of a coating material for forming a resin film containing dispersion A-1) Except for changing Dispersion 1 to 2.475 g of Dispersion A-1 and changing the amount of methyl ethyl ketone to 0.892 g, the same procedure as in Example 1 was carried out to obtain Coating material 12 for forming a resin film. The ATO concentration in Coating material 12 was 24.6 parts by mass per 100 parts by mass of the binder resin.

[0138] (Preparation of resin film containing cured product of coating film of coating material 12 for forming resin film) A PEN film 12 having a resin film 12 on its surface was produced in the same manner as in Example 1, except that a coating material 12 for forming a resin film was used. The surface resistivity of the obtained PEN film 12 was measured and found to be 8.61 (LOGΩ / □), the surface roughness was 0.1055 μm, and the thickness of the resin film was 3.19 μm.

[0139] Comparative Example 2 (Preparation of a coating material for forming a resin film containing dispersion B-1) Dispersion 1 was replaced with 1.238 g of Dispersion B-1, and the amount of methyl ethyl ketone was increased to 2.122 A resin film-forming coating material 13 was obtained in the same manner as in Example 1, except that the amount of ATO was changed to 100 parts by mass of the binder resin. The ATO concentration in coating material 13 was 24.6 parts by mass with respect to 100 parts by mass of the binder resin.

[0140] (Preparation of resin film containing cured product of coating film of coating material 13 for forming resin film) A PEN film 13 having a resin film 13 on its surface was produced in the same manner as in Example 1, except that a coating material 13 for forming a resin film was used. The surface resistivity of the obtained PEN film 13 was measured and found to be 12.05 (LOGΩ / □), the surface roughness was 0.0280 μm, and the thickness of the resin film was 2.50 μm.

[0141] Comparative Example 3 (Preparation of Dispersion 12) 25.0 g of Dispersion A-5 was weighed out, and 12.5 g of Dispersion B-1 was added dropwise to Dispersion A-5 while stirring using a magnetic stirrer. Stirring was then continued for 30 minutes to obtain Dispersion 12. Dispersion 12 had an ATO concentration of 26.7% by mass, a content of ATO particles A in the tin oxide particles of 50% by mass, and a content of ATO particles B in the tin oxide particles of 50% by mass. The average particle size of the tin oxide particles in Dispersion 12 was measured to be 301.2 nm, and the polydispersity index was 0.325.

[0142] (Preparation of a coating material for forming a resin film containing dispersion 12) A resin film-forming coating material 14 was obtained in the same manner as in Example 1, except that dispersion 1 was changed to dispersion 12. The ATO concentration in coating material 14 was 24.6 parts by mass relative to 100 parts by mass of the binder resin.

[0143] (Preparation of resin film containing cured product of coating film of coating material 14 for forming resin film) A PEN film 14 having a resin film 14 on its surface was produced in the same manner as in Example 1, except that a paint 14 for forming a resin film was used. The surface resistivity of the obtained PEN film 14 was measured and found to be 11.91 (LOGΩ / □), the surface roughness was 0.0033 μm, and the thickness of the resin film was 2.91 μm.

[0144] Comparative Example 4 (Preparation of Dispersion 13) 25.0 g of Dispersion A-6 was weighed out, and 12.5 g of Dispersion B-8 was added dropwise to Dispersion A-6 while stirring it using a magnetic stirrer. Stirring was then continued for 30 minutes to obtain Dispersion 13. Dispersion 13 had an ATO concentration of 26.7 mass%, a content of ATO particles A in the tin oxide particles of 50 mass%, and a content of ATO particles B in the tin oxide particles of 50 mass%. An attempt was made to measure the average particle size of the tin oxide particles in Dispersion 13, but due to the aggregation of ATO particles in the dispersion, the particle size exceeded the limit of particle size measurement and could not be measured. Therefore, Dispersion 13 was not used to create paint or a resin film.

[0145] Comparative Example 5 (Preparation of Dispersion 14) 25.0 g of Dispersion A-1 was weighed out, and 12.5 g of Dispersion B-9 was added dropwise to Dispersion A-1 while stirring it using a magnetic stirrer. Stirring was then continued for 30 minutes to obtain Dispersion 14. Dispersion 14 had an ATO concentration of 26.7 mass%, a content of ATO particles A in the tin oxide particles of 50 mass%, and a content of ATO particles B in the tin oxide particles of 50 mass%. The average particle size of the tin oxide particles in Dispersion 14 was measured to be 4916.2 nm, and the polydispersity index was 0.917.

[0146] (Preparation of a coating material for forming a resin film containing dispersion 14) Resin film-forming paint 15 was obtained in the same manner as in Example 1, except that dispersion 1 was changed to dispersion 14. The ATO concentration in paint 15 was 24.6 parts by mass relative to 100 parts by mass of the binder resin.

[0147] (Preparation of resin film containing cured product of coating film of coating material 15 for forming resin film) A PEN film 15 having a resin film 15 on its surface was produced in the same manner as in Example 1, except that a paint 15 for forming a resin film was used. The surface resistivity of the obtained PEN film 15 was measured, but it was not possible to measure it because the lower limit of the measuring device had been changed. The surface roughness was 0.3880 μm, and the thickness of the resin film was 2.77 μm.

[0148] Comparative Example 6 Surface layer coating material 2 for intermediate transfer belts was prepared in the same manner as in Example 12, except that dispersion liquid 2 was replaced with dispersion liquid A-1. Intermediate transfer belt 2 was produced using this coating material in the same manner as in Example 12. The surface resistivity of this intermediate transfer belt 2 was measured and found to be 8.84 (LOG Ω / □). The surface roughness was 0.1214 μm, and the resin film thickness was 3.15 μm.

[0149] Comparative Example 7 Surface layer coating material 3 for intermediate transfer belts was prepared in the same manner as in Example 12, except that dispersion 2 was replaced with dispersion B-1. Intermediate transfer belt 3 was produced using this coating material in the same manner as in Example 12. The surface resistivity of this intermediate transfer belt 3 was measured and found to be 12.55 (LOG Ω / □). The surface roughness was 0.0034 μm, and the resin film thickness was 3.16 μm. [Table 3] In Table 3, ATO particles A represent antimony-containing tin oxide particles A that have not been treated with a silane coupling agent, and ATO particles B represent antimony-containing tin oxide particles B that have been treated with a silane coupling agent. The ATO concentration (mass%) is the total content of ATO particles A and ATO particles B in the conductive dispersion, and ATO particles A (percentage%) is the total content of ATO particles A in the conductive dispersion. The content (parts by mass) of ATO particles A relative to 100 parts by mass of the total mass of ATO particles A and ATO particles B, ATO particles B (percentage %) is the content (parts by mass) of ATO particles B relative to 100 parts by mass of the total mass of ATO particles A and ATO particles B in the conductive dispersion, the percentage of silicon element in ATO particles B (% by mass) indicates the percentage (% by mass) of silicon element relative to all elements measured when ATO particles B are measured by fluorescent X-ray, and particle size indicates the cumulant average particle size (nm). [Table 4] In Table 4, ATO particles A represent antimony-containing tin oxide particles A that have not been treated with a silane coupling agent, and ATO particles B represent antimony-containing tin oxide particles B that have been treated with a silane coupling agent. ATO particles A (% percentage) represents the content (parts by mass) of ATO particles A relative to 100 parts by mass of the total mass of ATO particles A and ATO particles B in the conductive dispersion. ATO particles B (% percentage) represents the content (parts by mass) of ATO particles B relative to 100 parts by mass of the total mass of ATO particles A and ATO particles B in the conductive dispersion. The ATO content (parts by mass) represents the content (parts by mass) of ATO particles relative to 100 parts by mass of binder resin. In the column for surface resistivity, "U" indicates that measurement was not possible. Example 12, Comparative Example 6, and Comparative Example 7 represent the results of electrophotographic intermediate transfer belts that were fabricated and evaluated.

[0150] [Evaluation results] The evaluation results of the examples and comparative examples will be described below. In all of Examples 1 to 11, a resin film was formed that had both high conductivity and good surface roughness.

[0151] The conductive dispersion according to Comparative Example 1 is a dispersion containing only ATO particles A as tin oxide particles, and the conductive dispersion according to Comparative Example 2 is a dispersion containing only ATO particles B as tin oxide particles. When each of these is used alone, high conductivity and low surface roughness are in a trade-off relationship, and it was confirmed that it is difficult to achieve both high conductivity and low surface roughness.

[0152] The conductive dispersion liquid according to Comparative Example 3 is a dispersion liquid containing no organic acid. It is generally known that the tendency of ATO particles to aggregate is affected by the pH of the dispersion medium. Since the isoelectric point of the ATO potential is on the acidic side, it is presumed that by mixing an organic acid, the pH shifts to the acidic side as the paint dries, causing the ATO particles to aggregate. Therefore, if the dispersion does not contain an organic acid, the ATO particles are less likely to aggregate. This is thought to be why no conductive path is formed, resulting in an increase in resistivity. This suggests that the conductive dispersion needs to contain an organic acid to impart conductivity.

[0153] The conductive dispersion according to Comparative Example 4 does not contain an amine compound. The amine compound is added to exhibit a dispersing effect by adsorbing to the surface of the ATO particles. It is believed that the dispersion does not have a dispersing effect on the ATO particles because the dispersion does not contain an amine compound, which causes the dispersion to aggregate to the extent that particle size measurement is difficult. This suggests that, in order to achieve the effects of the present disclosure, the conductive dispersion must contain an amine compound.

[0154] The conductive dispersion liquid according to Comparative Example 5 is a dispersion liquid that does not contain a phosphorus compound. Like amine compounds, phosphorus compounds are added to adsorb to the surface of ATO particles and exhibit a particle dispersion effect. As described above, phosphorus compounds have a stronger adsorption force to metal oxide particles than amine compounds. The absence of a phosphorus compound in the dispersion liquid makes it difficult for the ATO particles to disperse, and the ATO particles tend to aggregate. This suggests that a phosphorus compound is necessary to improve the dispersibility of the ATO particles in order to achieve the effects of the present disclosure.

[0155] In Example 12, an intermediate transfer belt, which is an electrophotographic member, was produced using Dispersion 2. The surface resistivity (LOGρS) of this intermediate transfer belt was 9.94 Ω / □, and the surface roughness was 0.0039 μm, and the intermediate transfer belt had a surface layer film with appropriate resistivity required for intermediate transfer and small surface roughness.

[0156] On the other hand, in Comparative Example 6, the surface layer coating material for the intermediate transfer belt was prepared using Dispersion A-1. The intermediate transfer belt 2 prepared using this coating material had a large surface roughness. As a result, there is a concern that the toner cleaning blade may wear or chip due to sliding.

[0157] In Comparative Example 7, a surface layer coating material for an intermediate transfer belt was prepared using only the dispersion liquid B-1. The intermediate transfer belt 3 prepared using this coating material had a small surface roughness, but the surface resistivity was too high, making it difficult to apply to electrophotographic members.

[0158] To confirm the effect of reducing surface roughness, the following evaluation was performed on intermediate transfer belts 1 and 2 using an electrophotographic image forming apparatus configured as shown in Fig. 2. That is, the intermediate transfer belts were installed as intermediate transfer bodies, and blade cleaning was performed while printing images to evaluate toner cleaning performance. This evaluation was carried out under an environment of a temperature of 15°C and a relative humidity of 10%, using OCE Extra (basis weight 80 g / m) as the recording medium S. 2 ) JIS A4 size paper was used, and two sheets were printed intermittently until toner cleaning failure occurred, and it was judged whether or not toner slipped through the cleaning blade 31.

[0159] Specifically, with the secondary transfer voltage turned off (0V), laser light was irradiated onto the photosensitive drums 1y and 1m so as to record a red image (Y toner and M toner) over the entire surface of an A4 size sheet. Thereafter, the secondary transfer voltage was set to an appropriate value, and three blank sheets were passed through continuously. Because the secondary transfer voltage was not applied, the Y toner and M toner transferred from the photosensitive drums 1y and 1m to the entire surface of the electrophotographic belt were hardly transferred to the recording medium at the secondary transfer section, and instead entered the cleaning blade in the cleaning device. If the entered toner was removed from the electrophotographic belt, the three subsequent sheets that were passed through were output as completely blank sheets. On the other hand, if it was not removed, the transfer-residual toner that slipped through the cleaning blade was then transferred to the recording medium at the secondary transfer section. In other words, the transfer-residual toner was transferred onto the blank paper, and the toner was left on the recording medium. The image is output as a poorly scanned image.

[0160] The above-mentioned evaluation was carried out at the time when 100,000 sheets had been passed, 200,000 sheets had been passed, 300,000 sheets had been passed, and 400,000 sheets had been passed. When intermediate transfer belt 1 was used, no toner cleaning failure occurred even after 400,000 sheets had been passed, confirming that the intermediate transfer belt 1 is an electrophotographic belt with excellent durability. On the other hand, intermediate transfer belt 2 experienced toner cleaning failure after 400,000 sheets had been passed, indicating that it was inferior in durability to transfer belt 1. After the test using intermediate transfer belt 2, the cleaning blade was observed near the point of contact with the electrophotographic belt, and wear marks were confirmed to be present on the cleaning blade.

[0161] The present disclosure includes the following configurations. (Configuration 1) A conductive dispersion liquid containing tin oxide particles and a dispersion medium, the conductive dispersion further contains an organic acid, a phosphorus compound, and an amine compound; the tin oxide particles are dispersed in the dispersion medium, the tin oxide particles in the conductive dispersion have a cumulant average particle size of 90 to 400 nm; the organic acid, the phosphorus compound, and the amine compound are dissolved in the dispersion medium; The conductive dispersion liquid is characterized in that the tin oxide particles include antimony-containing tin oxide particles A that have not been treated with a silane coupling agent, and antimony-containing tin oxide particles B that have been treated with a silane coupling agent. (Configuration 2) the content of the tin oxide particles in the conductive dispersion is 5.0 to 50.0 mass %, 2. The conductive dispersion according to claim 1, wherein the content of the antimony-containing tin oxide particles A in the conductive dispersion is 25 to 75 parts by mass per 100 parts by mass of the total of the antimony-containing tin oxide particles A and the antimony-containing tin oxide particles B. (Configuration 3) 3. The conductive dispersion according to claim 1, wherein when the antimony-containing tin oxide particles B contained in the conductive dispersion are measured by fluorescent X-ray, the proportion of silicon element to all elements measured is 5.0 to 15.0 mass%. (Configuration 4) the content of the organic acid is 0.10 to 2.00 parts by mass relative to 100 parts by mass of the tin oxide particles, the content of the amine compound is 0.25 to 1.00 parts by mass relative to 100 parts by mass of the tin oxide particles, 4. The conductive dispersion liquid according to any one of configurations 1 to 3, wherein the content of the phosphorus compound is 0.50 to 10.00 parts by mass with respect to 100 parts by mass of the tin oxide particles. (Configuration 5) 5. The conductive dispersion liquid according to any one of configurations 1 to 4, wherein the molecular weight of the amine compound is 180 to 500, and the amine compound is at least one compound selected from the group consisting of secondary amines and tertiary amines represented by the following formula (1): TIFF2026003395000008.tif26170 (in formula (1), R 1 and R 2 each independently represents an aliphatic hydrocarbon group, R 3 represents a hydrogen atom or an aliphatic hydrocarbon group. (Configuration 6) 6. The conductive dispersion according to any one of configurations 1 to 5, wherein the molecular weight of the phosphorus compound is 300 to 5,000, and the phosphorus compound is at least one compound selected from the group consisting of diesters and triesters represented by the following formula (2): TIFF2026003395000009.tif35170 (in formula (2), R 4 ~R 6 represents a hydrogen atom or an organic group, and R 4 ~R 6 At least two selected from the group consisting of represent organic groups. (Configuration 7) 7. The conductive dispersion liquid according to any one of configurations 1 to 6, wherein the dispersion medium is an organic solvent. (Configuration 8) A paint for forming a resin film containing a resin At least one selected from the group consisting of the resin and a precursor of the resin; Tin oxide particles; Organic acids and a phosphorus compound; an amine compound; Including, The coating material for forming a resin film is characterized in that the tin oxide particles include antimony-containing tin oxide particles A that have not been treated with a silane coupling agent, and antimony-containing tin oxide particles B that have been treated with a silane coupling agent. (Configuration 9) 9. The coating material according to claim 8, wherein the resin is a (meth)acrylic resin. (Configuration 10) 10. A resin film comprising a resin, the resin film being a cured product of a coating film of the paint according to Configuration 8 or 9. (Configuration 11) A component having a substrate and a resin film containing a resin on the surface of the substrate, wherein the resin film is a cured product of a coating film of the paint according to Configuration 8 or 9. (Configuration 12) 12. The member according to claim 11, wherein the member is an electrophotographic belt having an endless belt shape. (Configuration 13) 13. An electrophotographic image forming apparatus comprising the member according to claim 12 as an intermediate transfer member. [Explanation of symbols]

[0162] 101 Tin oxide particles, 101a ATO particles not treated with a silane coupling agent, 101b ATO particles treated with a silane coupling agent, 102 Resin 1 photosensitive drum, 2 conductive roller, 3 laser scanner, 4 developing unit, 5 electrophotographic belt, 6 tension roller, 7 drive roller, 8 primary transfer roller, 9 secondary transfer roller, 10 current detection circuit, 12 feed roller, 13 transport roller, 14 toner recovery blade, 15 fixing unit, 20 paper feed cassette, 21 paper discharge tray, 30 belt cleaning device, 31 cleaning blade, 41 developing roller, 42 developing container, 43 developing blade, 92 secondary transfer opposing roller, 151 heating roller, 152 pressure roller, 160 image density sensor, S recording medium

Claims

1. A conductive dispersion liquid containing tin oxide particles and a dispersion medium, the conductive dispersion further contains an organic acid, a phosphorus compound, and an amine compound; the tin oxide particles are dispersed in the dispersion medium, the cumulant average particle size of the tin oxide particles in the conductive dispersion is 90 to 400 nm; the organic acid, the phosphorus compound, and the amine compound are dissolved in the dispersion medium; The conductive dispersion liquid is characterized in that the tin oxide particles include antimony-containing tin oxide particles A that have not been treated with a silane coupling agent, and antimony-containing tin oxide particles B that have been treated with a silane coupling agent.

2. the content of the tin oxide particles in the conductive dispersion is 5.0 to 50.0 mass %, 2. The conductive dispersion according to claim 1, wherein the content of the antimony-containing tin oxide particles A in the conductive dispersion is 25 to 75 parts by mass relative to 100 parts by mass in total of the antimony-containing tin oxide particles A and the antimony-containing tin oxide particles B.

3. 2. The conductive dispersion according to claim 1, wherein, when the antimony-containing tin oxide particles B contained in the conductive dispersion are measured by fluorescent X-ray, the ratio of silicon element to all elements measured is 5.0 to 15.0 mass%.

4. the content of the organic acid is 0.10 to 2.00 parts by mass relative to 100 parts by mass of the tin oxide particles, the content of the amine compound is 0.25 to 1.00 parts by mass relative to 100 parts by mass of the tin oxide particles, 2. The conductive dispersion according to claim 1, wherein the content of the phosphorus compound is 0.50 to 10.00 parts by mass with respect to 100 parts by mass of the tin oxide particles.

5. 2. The conductive dispersion according to claim 1, wherein the amine compound has a molecular weight of 180 to 500, and the amine compound is at least one compound selected from the group consisting of secondary amines and tertiary amines represented by the following formula (1): (In formula (1), R １ and R ２ each independently represents an aliphatic hydrocarbon group, R ３ represents a hydrogen atom or an aliphatic hydrocarbon group.

6. 2. The conductive dispersion according to claim 1, wherein the phosphorus compound has a molecular weight of 300 to 5000, and the phosphorus compound is at least one compound selected from the group consisting of diesters and triesters represented by the following formula (2): (In formula (2), R ４ ~R ６ represents a hydrogen atom or an organic group, and R ４ ~R ６ A group consisting of At least two selected from the above represent an organic group.

7. The conductive dispersion according to any one of claims 1 to 6, wherein the dispersion medium is an organic solvent.

8. A paint for forming a resin film containing a resin At least one selected from the group consisting of the resin and a precursor of the resin; Tin oxide particles; Organic acids and a phosphorus compound; an amine compound; Including, The coating material for forming a resin film is characterized in that the tin oxide particles include antimony-containing tin oxide particles A that have not been treated with a silane coupling agent, and antimony-containing tin oxide particles B that have been treated with a silane coupling agent.

9. The paint according to claim 8, wherein the resin is a (meth)acrylic resin.

10. A resin film comprising a resin, the resin film being a cured product of a coating film of the paint according to claim 8 or 9.

11. A member having a substrate and a resin film containing a resin on the surface of the substrate, wherein the resin film is a cured product of a coating film of the paint according to claim 8 or 9.

12. 12. The member of claim 11, wherein the member is an electrophotographic belt having an endless belt configuration.

13. 13. An electrophotographic image forming apparatus comprising the member according to claim 12 as an intermediate transfer member.

Images