JPH1138794A - Image forming device, image forming method, and intermediate transfer body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain excellent transferability performance from an operation start under the high-temperature, high-humidity environment by setting the contact angle between the surface layer of an intermediate transfer body and water within the range of the specific angle, and sticking transfer auxiliary grains to the surface layer. SOLUTION: A contact angle between a surface layer 54 of an intermediate transfer body 5 and water is set to 50-120 deg., preferably 60-110 deg.. When the contact angle is smaller than 50 deg., a secondary transfer efficiency is lowered. When the contact angle is larger than 120 deg., the transfer auxiliary grains cannot be fully stuck, the grain quantity lacks, the secondary transfer efficiency is lowered, and defective cleaning occurs. The transfer auxiliary grains are stuck to the surface layer 54 of the intermediate transfer body 5 at such sticking strength that 30-95%, preferably 40-90%, of all stuck grains are removed from the surface of the intermediate transfer body 5 when an adhesive tape having the adhesive strength of 180-220 gf/cm is stuck to the intermediate transfer body 5 stuck with grains on the surface then is peeled off. The grain size of the transfer auxiliary grains is preferably set to 0.001-3 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, an image forming method, and an intermediate transfer member using an electrophotographic system, and more particularly, to a method for temporarily transferring a toner image formed on a first image carrier to an intermediate transfer member. The present invention relates to an image forming apparatus, an image forming method, and an intermediate transfer member for obtaining an image by further transferring (secondary transfer) onto a second image carrier after transferring the image onto a second image carrier (primary transfer).

[0002]

2. Description of the Related Art An image forming apparatus using an intermediate transfer member transfers an image from a first image carrier to a second image carrier adhered to or adsorbed on a transfer drum. JP-A-63-301960) is superior in the following points.

In other words, processing and control (for example, gripping, adsorbing, and giving a curvature to a gripper, etc.) are performed on the second image bearing member in that the color misregistration at the time of superimposing the toner images of each color is small. Since it is not necessary, the second image carrier can be selected in various ways.

For example, a thin paper (40 g / m ² paper) to a thick paper (200 g / m ² paper) can be selected, and the width and the length of the paper are not limited. Therefore, it is possible to use envelopes, postcards, label paper, and the like. As described above, a full-color copying machine or printer of the intermediate transfer system has many advantages, and a copying machine or a printer equipped with an intermediate transfer member is already becoming widespread.

In addition, with the rapid spread of image input devices such as personal computers, digital cameras, and image scanners in recent years, the demand for full-color printers and copiers has also increased significantly, and the demand for a wide range of users and use environments has been sufficiently increased. It is necessary to be able to respond. Therefore, the maintenance cost has been reduced and the ease of maintenance has been improved.
Furthermore, it is necessary to achieve stable image quality that is not affected by temperature or humidity.

In order to meet these demands, the transfer performance (secondary transfer) from the intermediate transfer body to a transfer material such as paper as a second image carrier is not required, and the intermediate transfer is not performed at the secondary transfer portion. Removal (cleaning) of developer (toner) remaining on the body
Performance is a very important factor. This is because the cleaning property of the intermediate transfer member greatly affects the service life of the intermediate transfer member, the configuration of the main body device, and the ease of maintenance, and the transfer efficiency greatly affects image quality and cleaning performance. This transfer efficiency tends to decrease particularly under a high-temperature and high-humidity environment.

As means for improving the releasability of the surface of the intermediate transfer member for the purpose of improving transfer performance, for example, JP-A-7-2
Japanese Patent No. 34592 discloses that fine particles having a size not more than half the toner particle diameter are fixed to the elastic layer of the intermediate transfer member. Also, Japanese Patent Application Laid-Open No. 9-230717 describes an intermediate transfer member coated with beads having a specific particle size. Further, there are means such as forming a coating film of a water-repellent resin and using a water-repellent resin belt.

As another means for improving transferability,
JP-A-8-248776 describes a copying machine having a built-in device for applying a lubricant to an intermediate transfer member.

[0009]

However, in these methods, no consideration is given to a decrease in transfer efficiency in a high-temperature, high-humidity environment.

Accordingly, it is an object of the present invention to provide an image forming apparatus, an image forming method, and an intermediate transfer member having excellent transfer performance even in a high temperature and high humidity environment from the beginning of use.

Another object of the present invention is to provide an image forming apparatus, an image forming method, and an intermediate transfer member having a long durable life and capable of reducing running costs.

Another object of the present invention is to provide an image forming apparatus, an image forming method, and an intermediate apparatus capable of simplifying the structure of the main body, improving the ease of maintenance, and performing high-speed printing. To provide a transcript.

[0013]

That is, according to the present invention, a first image carrier and a toner image formed on the first image carrier are primarily transferred, and the transferred toner image is transferred to the first image carrier. In an image forming apparatus having an intermediate transfer member for secondary transfer onto a second image carrier, a contact angle between a surface layer of the intermediate transfer member and water is 50 to 120 °, and transfer assistance is provided to the surface layer. An image forming apparatus having particles adhered thereto.

The present invention is also directed to a method for primary transferring a toner image from a first image bearing member to an intermediate transfer member, and transferring the transferred toner image from the intermediate transfer member to a second image bearing member on a second image bearing member. An image forming method for transferring, wherein an intermediate transfer member having a surface layer to which a contact angle with water is 50 to 120 ° and transfer auxiliary particles are adhered is used as the intermediate transfer member. Is the way.

Further, the present invention provides an intermediate transfer member for primary-transferring a toner image formed on a first image carrier and secondary-transferring the transferred toner image to a second intermediate transfer member. The intermediate transfer member has a contact angle with water of 50 to 120 °.
And an intermediate transfer member having a surface layer to which transfer assisting particles are adhered.

In order to improve the secondary transfer performance, it is effective to reduce the adhesive force between the toner and the intermediate transfer member, and the effect is obtained by making the surface of the intermediate transfer member highly lubricated and high release. What is obtained is as described above. However, when printing is continuously performed in a high-temperature and high-humidity environment, higher transfer performance is required, and the release property of the material of the surface layer of the intermediate transfer member alone may not be sufficient.

Therefore, in the present invention, a synergistic transfer property improving effect is obtained by attaching transfer auxiliary particles to the surface layer having a high release property, and the cleaning performance is greatly improved. Although the reason is not clear, the transfer assisting particles are not fixed to both the toner and the intermediate transfer body, and can move freely, and also because the fine particles are interposed between the toner and the intermediate transfer body. It is considered that the contact area between the two is reduced and the distance is increased, so that the adhesive force of the toner is remarkably reduced, and as a result, very high transfer performance can be obtained.

In the present invention, both high releasability of the surface of the intermediate transfer member and transfer auxiliary particles are indispensable, and the effect of the present invention cannot be obtained by only one of them. In particular, in the present invention, it is important that the transfer auxiliary particles are merely attached to the surface layer of the intermediate transfer member, that is, the transfer auxiliary particles are in a state where they can freely move on the surface of the intermediate transfer member to some extent.
When the transfer auxiliary particles are fixed to the surface layer of the intermediate transfer body, for example, a part or all of the particles are buried and fixed in the surface layer of the intermediate transfer body to form a part of the surface layer. In such a case, the particles cannot function as transfer assisting particles.

From this point of view, the above-mentioned Japanese Patent Application Laid-Open No. Hei 7-2345
The particles described in JP-A-92-92 and the beads described in JP-A-9-230717 cannot be the transfer assisting particles of the present invention. This is because Japanese Patent Application Laid-Open No. 7-234592 states that particles are firmly fixed, hardly removed even when wiping with an alcohol solvent, and that the intermediate transfer member can be cleaned and reused. This is because Japanese Unexamined Patent Publication No. 9-230717 discloses that beads should not be easily separated during transfer and cleaning. Therefore, these particles are simply used by being fixed to the transfer surface as an agent for improving the releasability of the transfer surface, and are completely different from the transfer auxiliary particles of the present invention.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The contact angle of the surface layer of the intermediate transfer member with water in the present invention is 50 to 120 °, preferably 60.
１１０110 °. When the contact angle is smaller than 50 °, the secondary transfer efficiency is reduced. Particularly, in a high-temperature and high-humidity environment, the amount of water adsorbed on the surface of the intermediate transfer member increases, resulting in a decrease in secondary transfer efficiency and a deterioration in cleaning performance, resulting in an image defect due to poor cleaning or a decrease in throughput.

On the other hand, if the contact angle is larger than 120 °, the transfer assisting particles cannot be sufficiently adhered, and the amount of the particles is insufficient.
It is also difficult to manufacture.

The contact angle can be measured using a goniometer-type contact angle measuring device (manufactured by Kyowa Interface Science Co., Ltd.).

The adhesion strength of the transfer assisting particles in the present invention is, specifically, an adhesive strength of 180 to 220 gf / c.
m of the adhesive tape is adhered to the intermediate transfer member having the particles adhered to the surface, and when peeled off, 30 to 95%, preferably 40 to 90% of the total number of adhered particles are removed from the surface of the intermediate transfer member. .

If the removal rate is less than 30%, it means that the transfer auxiliary particles are firmly attached on the intermediate transfer member, and it is not possible to obtain sufficient transfer performance. When the removal rate is more than 95%, the adhesion strength is insufficient,
In a short period of time, a large amount of transfer assisting particles are transferred to a transfer material such as paper.
Cleaning failure occurs during durability.

Hereinafter, the method for measuring the adhesion strength of the transfer assisting particles in the present invention will be described in more detail. The pressure-sensitive adhesive tape used in the measurement has a pressure-sensitive adhesive strength of 180 to 220 gf / cm according to JIS Z0237 180 ° peeling method. The pressure-sensitive adhesive tape is attached to the surface of the intermediate transfer member to which the transfer auxiliary particles have adhered. Thereafter, the end of the adhesive tape is gripped and peeled from the intermediate transfer member at a speed of 300 mm / sec in the 180 ° direction. Next, a portion of the intermediate transfer member peeled off with the adhesive tape is cut out to obtain a sample, which is enlarged using a scanning electron microscope (SEM) to calculate the number of particles per unit area. In addition, the number of particles at a portion where the adhesive tape peeling test is not performed is calculated in the same manner. The magnification and measurement area of the SEM can be selected under conditions that are easy to measure according to the particle size and adhesion amount of the transfer assisting particles, but the measurement range is set so that the number of calculated particles before separation is 100 or more. Set. Particles are counted by the number of primary particles. The number of samples is set to 5 points, and the elimination rate is calculated based on the following equation using the average value thereof.

Particle removal rate (%) = (A−B) / A × 100 A: Number of particles on the surface of the intermediate transfer member without tape separation B: Number of particles on the surface of the intermediate transfer member after tape separation

In the case where the amount of adhered particles is large and the particles are multi-layered, a sufficient number of particles are not peeled off by a single peeling test and remain on the surface of the intermediate transfer member. The above-mentioned peeling test is repeated until almost no particles are peeled off from the surface of the intermediate transfer member. The number of times of peeling is determined based on the number of transfer assisting particles adhered to the adhesive surface of the peeled tape, and the number of peeling is determined until it becomes at least about 1/10 or less as compared with the number of the tapes peeled first.

The adhesion strength is determined by the same method as described above.
EM is used to calculate the number of particles attached in a unit area of the adhesive tape. This is performed on the adhesive surfaces of all the tapes subjected to the peel test, and the total value is defined as the number of peeled particles. Further, a part of the intermediate transfer member is cut out and SEM
Calculate the number of remaining particles by expanding.

From these, the removal rate is calculated by the following equation (2).

Particle removal rate (%) = (T ₁ + T ₂ + T ₃ + ... T _X ) /
(T ₁ + T ₂ + T ₃ + ... T _X + B) × 100 T _{1 to} T _X : Number of particles adhered to the tape adhesive surface. X is the number of times the peel test was performed. B: The number of particles on the surface of the intermediate transfer member after the tape was peeled.

Further, when the particles adhere in an aggregated state, the calculation is performed by the following method. From the SEM photograph, the longest diameter and the shortest diameter of all the aggregated particles in the calculation range are measured, and the number of particles included in the measurement range is calculated as a sphere having the average value as the diameter.

In the present invention, the particle size of the transfer assisting particles is preferably 0.001 to 3 μm. When the particle size is larger than 3 μm, it is difficult to cover the surface layer uniformly, and it is easy to cause transfer unevenness and voids. Also,
If it is smaller than 0.001 μm, the effect as the transfer auxiliary particles tends to be insufficient, and the transfer performance tends to decrease. It is more preferably 1 μm or less, and further preferably 0.005 to 1 μm.

The particle diameter of the above particles is determined by dry mixing about 0.5% by weight of particles to be measured with polyethylene particles having a particle diameter of about 10 μm and adhering to the surface.
Observe at 30,000-fold magnification using M) and determine the average value of the longest diameters of 20 randomly selected primary particles.

The material of the transfer assisting particles is not particularly limited, but is preferably an inorganic particle having a high hardness, and more preferably a particle having a hydrophobicity of 30% or more by surface treatment. Is preferable because the influence of temperature and humidity can be reduced. The degree of hydrophobization that can exert more sufficient effect is 40
% Or more.

As the inorganic particles, for example, silicon dioxide (silica), titanium dioxide (titania), aluminum oxide (alumina), magnesium oxide (magnesia),
Examples include tin oxide, strontium titanate, and cerium oxide, and a mixture of a plurality of these may be used. Among them, silica, titania and alumina are preferred.

Examples of the method for hydrophobizing include a method of chemically treating with a treating agent such as an organosilicon compound which reacts with or physically adsorbs particles. Examples of such organosilicon compounds include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethylchlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane , Bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilyl acrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyl Dimethoxysilane, diphenyldiethoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxy San, 1,3-diphenyltetramethyldisiloxane and dimethylpolysiloxane having from 2 to 12 siloxane units per molecule and having hydroxyl groups bonded to Si each having one terminal unit at each terminal Can be
These are used alone or as a mixture of two or more.

The degree of hydrophobicity of the particles is determined as follows. First, 1 g of particles are mixed in 100 ml of pure water, and shaken for 10 minutes with a shaker. Thereafter, the mixture is allowed to stand for a while, and then the particles and the aqueous layer are separated. The aqueous layer is sampled and the transmittance of light having a wavelength of 500 nm is measured. The value obtained by dividing the transmittance at this time by the transmittance of pure water is defined as the degree of hydrophobicity.

[0038]

[Outside 1]

The method for attaching the transfer assisting particles to the intermediate transfer member is not particularly limited, but it is necessary to adjust the processing conditions so that the adhesive strength falls within the range of the present invention.

For example, a brush-like or roller-like coating member such as sponge or elastic rubber is brought into contact with the intermediate transfer member, and both are driven and rotated to supply the transfer assisting particles to the contact portion. A method in which an elastic blade is pressed against an intermediate transfer member to supply transfer auxiliary particles to a contact portion. Further, a method in which a sheet-like member such as a nonwoven fabric to which particles are attached in advance is wound around the intermediate transfer member for about half a round, and the intermediate transfer member is rotated in a state where tension is applied. Further, a wet method of uniformly dispersing particles to be adhered in an appropriate solvent, applying the dispersion to the surface of the intermediate transfer member by a spraying method or a dipping method, and then drying the liquid component can also be used.

Factors that affect the adhesion strength of the particles include the material of the intermediate transfer member and the particles, the number of rotations and pressing pressure of the intermediate transfer member and the coating member, and the supply amount of the particles. In the case of the wet method, select the type of solvent,
The adhesion state of the particles can also be adjusted by, for example, mixing a very small amount of a binder component in a solvent.

The shape of the intermediate transfer member used in the present invention can be varied as required. For example, FIG.
And a drum shape as shown in FIG. 4 or a belt shape as shown in FIG. 5 and FIG. The layer structure is not particularly limited, but in the present invention, at least the contact angle between the surface layer of the intermediate transfer member and water must be 50 to 120 °.

In each of the figures, 5 is a drum-shaped intermediate transfer member, 51 is a rigid cylindrical conductive support, 52 is an elastic layer, 54 is a surface layer, 53 is an intermediate layer, and 55 is a belt-shaped intermediate transfer member. Reference numeral 56 denotes transfer assisting particles, and 57 denotes a seamless resin belt.

As the conductive support, aluminum,
Metals and alloys such as iron, copper and stainless steel, and conductive resins and the like in which carbon and metal particles are dispersed can be used, and the shape thereof is cylindrical as described above, or a shaft penetrating the center of the cylinder. And those in which the inside of a cylinder is reinforced.

The intermediate transfer member of the present invention has lubricity on the elastic layer,
It is preferable to provide a surface layer in which a highly water-repellent lubricant powder is dispersed in a binder, and it is preferable that a powder having a particle size equal to or less than half of the toner particle size is mixed in the transfer layer in an amount of 20% by weight or more. .

There are no particular restrictions on the lubricant, but various types of fluororubber, fluoroelastomer, carbon fluoride obtained by bonding fluorine to graphite or graphite, polytetrafluoroethylene (PTFE), polyvinyldene fluoride (PVDF),
Ethylene-tetrafluoroethylene copolymer (ETF
E) and fluorine compounds such as tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), silicone compounds such as silicone resin particles, silicone rubber and silicone elastomer, polyethylene (PE), polypropylene (PP), polystyrene (P
S), a resin such as an acrylic resin, a polyamide resin, a phenol resin, and an epoxy resin, and the like are preferable, and more preferably fluorine-containing resin particles having particularly high lubricity and water repellency.

As shown in FIG. 6, a belt made of a resin-made seamless belt or sheet may be used as an intermediate transfer member. In this case, a fluorine-based or silicone-based material having high releasability is also used. It is preferable to use the resin of

Other materials of the intermediate transfer member in the present invention include:
There is no particular limitation as long as the surface properties are not inhibited. For example: Examples of elastomers and rubbers include styrene-butadiene rubber, high styrene rubber, butadiene rubber, isoprene rubber, ethylene-propylene copolymer, nitrile butadiene rubber (NB
R), chloroprene rubber, butyl rubber, silicone rubber, fluorine rubber, nitrile rubber, urethane rubber, acrylic rubber, epichlorohydrin rubber, norbornene rubber and the like. In addition, polystyrene as resins,
Chloropolystyrene, poly-α-methylstyrene, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer ( Styrene-methyl acrylate copolymer, styrene
Ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-phenyl acrylate copolymer, etc.), styrene-methacrylic ester copolymer (styrene-methyl methacrylate) Copolymers, styrene-ethyl methacrylate copolymers, styrene-phenyl methacrylate copolymers, etc.), styrene-α-methyl methacrylate copolymers, styrene-based styrene-acrylonitrile-acrylate copolymers, etc. Resin (Homopolymer or copolymer containing styrene or styrene substituent), vinyl chloride resin, rosin-modified maleic resin, phenol resin, epoxy resin, polyester resin, low molecular weight polyethylene,
Examples include low molecular weight polypropylene, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene-ethyl acrylate copolymer, xylene resin, fluororesin, polycarbonate, polyamide resin, polyvinyl butyral resin, and copolymers and mixtures thereof.

In the case of an intermediate transfer member having an elastic layer, the thickness of the elastic layer is preferably from 0.2 to 10 mm, the surface layer is from 3 to 100 μm, and the material is different from that of the elastic layer. Is preferred. Further, an intermediate layer may be provided between these layers as needed. In the case of an intermediate transfer member using a resin belt, the thickness is preferably about 30 to 300 μm.

The actual resistance of the intermediate transfer member used in the present invention is preferably 5 × 10 ^{4 to} 5 × 10 ⁹ Ω. In order to control the resistance, a conductive agent can be added as appropriate as long as the remarkable effects of the present invention can be obtained. Examples of the conductive agent include various conductive inorganic particles and carbon black, an ionic conductive agent, a conductive resin, and a conductive particle dispersed resin. Specifically, as the conductive inorganic particles, particles of titanium oxide, tin oxide, barium sulfate, aluminum oxide, strontium titanate, magnesium oxide, silicon oxide, silicon carbide, silicon nitride, etc. And surface-treated with carbon or the like. These shapes may be any shape such as a sphere, a fiber, a plate, and an irregular shape.
Examples of the ionic conductive agent include ammonium salts, alkyl sulfonates, phosphate esters, and perchlorates. Examples of the conductive resin include quaternary ammonium salt-containing polymethyl methacrylate, polyvinyl aniline, polyvinyl pyrrole, and polydiamine. Acetylene and polyethyleneimine; Also, as the conductive particle dispersed resin, carbon,
Urethane, conductive particles such as aluminum and nickel,
Examples thereof include those dispersed in resins such as polyester, vinyl acetate-vinyl chloride copolymer, and polymethyl methacrylate.

Known methods can be appropriately used for mixing and dispersing necessary constituent materials in various resin binders. When the binder component is an elastomer, a device such as a roll mill, a kneader, and a Banbury mixer is used. it can.

The intermediate transfer member of the present invention is manufactured, for example, as follows.

First, a metal roll is prepared as a cylindrical conductive support. Next, an elastic layer is formed by molding rubber, elastomer, resin, and the like on a metal roll by melt molding, injection molding, dip coating, spray coating, or the like. Further, the surface layer is provided by forming a material for the surface layer on the elastic layer by melt molding, injection molding, dip coating or spray coating. In this way, a two-layer intermediate transfer member having an elastic layer is obtained.

The belt-like intermediate transfer member is formed by extruding a resin material into a tube to obtain a single-layer seamless belt intermediate transfer member, by extruding an elastic layer, and after vulcanization, spray coating or dip coating. It is obtained by a method of forming a surface layer by a method or the like to obtain a belt-like intermediate transfer body having a two-layer structure, or a method of forming a single-layer or two or more-layer belt-like intermediate transfer body by centrifugal molding.

In the present invention, the method of cleaning the intermediate transfer member is not particularly limited.

For example, a method of scraping toner on an intermediate transfer member using an elastic blade capable of coming into contact with and separating from the intermediate transfer member is disclosed in JP-A-56-153357 and JP-A-5-153357.
No. 303310, and the like. In addition, a bias having a polarity opposite to that of the secondary transfer residual toner on the intermediate transfer member is applied to a fur brush capable of coming into contact with and separating from the intermediate transfer member, and the residual toner is collected, and is temporarily attached to a bias roller such as a metal roller. There is also a configuration in which the blade is then scraped off.

However, in such a cleaning means, since the cleaning member is repeatedly rubbed against the intermediate transfer member, abrasion of the surface of the intermediate transfer member and fusion of the developer are liable to occur. And the life of the intermediate transfer member is shortened. Further, a cleaning device using a fur brush requires a driving device, which not only complicates the main body device but also requires measures against scattering of toner.

As an auxiliary means for reducing the load of blade cleaning, there is a method in which the residual toner on the intermediate transfer member is charged to a polarity opposite to the potential of the photosensitive member serving as the first image carrier and returned to the photosensitive member by an electric field. For example, Japanese Patent Application Laid-Open No. 4-34056
No. 4, JP-A-5-297739, and the like.

Further, in Japanese Patent Application Laid-Open No. 1-105980, the following cleaning means is provided in order to eliminate waste by providing the same cleaning device on both the intermediate transfer member and the photosensitive member and to simplify the cleaning structure. Used. That is, a charger is provided for charging the residual toner on the intermediate transfer member to a polarity opposite to the charging potential of the photoconductor, and the secondary transfer residual toner on the intermediate transfer member is returned to the photoconductor only by the charger.

Such an electric field cleaning method has a small friction with the intermediate transfer member, and is effective in extending the life of the intermediate transfer member. However, when an image having a high image density and a high printing ratio is transferred under a high temperature and a high humidity, a plurality of cleaning operations are required, which causes a problem that the throughput is significantly reduced. In particular, it is most difficult to clean a line image or the like in which a plurality of colors with a large amount of toner to be transferred are overlapped.

Under high temperature and high humidity conditions, the charge amount of the toner decreases and the amount of moisture adhering to the surface of the intermediate transfer member increases.
This is because the secondary transfer efficiency and the electric field cleaning ability are reduced, and the application of the reverse charge to the secondary transfer residual toner is also insufficient. If not sufficiently cleaned, a so-called positive ghost or image deletion occurs in which a part of the previous image appears in the next image.

Further, as an electric field cleaning method which does not lower the throughput, a cleaning step of applying an opposite charge to the residual toner after transfer and returning the toner to the photosensitive member, and transferring the toner image formed on the photosensitive member to the intermediate transfer member. A method in which the primary transfer step is performed at the same time is very effective. Basically, this means only needs to provide means for charging the secondary transfer residual toner to the opposite polarity, and the secondary transfer residual toner is collected by the photoconductor cleaning device. It can be performed simultaneously with the transfer residual toner, and the maintenance property is good. Further, there is no need to provide a waste toner collecting and conveying device, a waste toner container, and the like around the intermediate transfer member, and the effect of reducing the size of the device and reducing costs is high.

However, in this method, when the amount of the transfer residual toner is large, cleaning failure easily occurs. In addition, when the transfer residual toner returns to the photosensitive member, it interferes with the primary transfer image.
Cleaning is more difficult than in the above-described method, such as the occurrence of a so-called negative ghost in which the density of the portion corresponding to the previous image decreases.

This depends on the amount of reverse charge that moves when the secondary transfer residual toner is collected on the photoreceptor. If the amount of charge is large, the transfer of normal toner is hindered and the image density of that portion is reduced. It is because it falls. For example, the amount of the secondary transfer residual toner is large, or the adhesion between the residual toner and the intermediate transfer body is strong,
This is the case when a large charge is needed to recover.

Therefore, the intermediate transfer member of the present invention having a high secondary transfer efficiency and a low toner adhering force can be used for electric field cleaning,
Among them, it is very excellent in matching with the primary transfer simultaneous cleaning.

The developer (toner) used in the present invention is:
It is preferable that fine particles having a particle diameter of 0.5 μm or less (hereinafter referred to as an external additive) adhere to the toner particles before external addition in an amount of 0.5% by weight or more. Further, at least one of such external additives is
It is preferable to use the same material as the transfer assisting particles attached to the intermediate transfer member in order to maintain high transferability. If the main materials are the same, the surface treatment conditions and the particle size may be different. The transfer assisting particles attached to the surface layer of the intermediate transfer member are gradually consumed and reduced by repeated printing, but only a small part of these particles attached to the toner are separated from the toner and separated. Residual on the surface to maintain transfer and cleaning performance. Therefore, the intermediate transfer member can exhibit high transfer performance over a long period of time. At this time, if the releasability of the surface of the intermediate transfer member is insufficient, these external additives are accumulated and fixed, resulting in a decrease in transfer performance. Particles migrate to the transfer material or the like, and no problem occurs.

The first image bearing member used in the present invention includes an electrophotographic photosensitive member, but is not particularly limited.

As the second image carrier, paper or O
Examples include an HP sheet, but are not particularly limited.

Hereinafter, an image forming apparatus using the intermediate transfer member of the present invention will be described.

FIG. 1 is a schematic sectional view of a color image forming apparatus (copier or laser printer) of the primary transfer simultaneous cleaning type. A medium-resistance elastic roller 5 is used as an intermediate transfer member, and a transfer belt is used as secondary transfer means.

Reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member (hereinafter, referred to as a photosensitive drum) as a first image carrier, which is rotated at a predetermined peripheral speed (process speed) in the direction of an arrow.

In the course of rotation, the photosensitive drum 1 is uniformly charged to a predetermined polarity and potential by the primary charging roller 2, and then is subjected to image exposure means (not shown).
An exposure 3 is performed by an imaging exposure optical system, a scanning exposure system using a laser scanner that outputs a laser beam modulated in accordance with a time-series electric digital pixel signal of image information, or the like. In this manner, an electrostatic latent image corresponding to the first color component image (for example, a yellow component image) of the target color image is formed.

Next, the electrostatic latent image is transferred to the first developing device 41.
(Yellow developing device) to develop with the first color yellow toner Y. Developing units 41, 42, 43 and 44
Each of the developing units (yellow, magenta, cyan and black) is rotated in a direction indicated by an arrow in the figure by a rotation driving device (not shown), and each developing unit is disposed so as to face the photosensitive drum 1 in a developing process. ing.

The intermediate transfer member 5 is driven to rotate at a predetermined peripheral speed in the direction of the arrow.

The above-mentioned first carrier formed and carried on the photosensitive drum 1
In the process of passing through the nip portion between the photosensitive drum 1 and the intermediate transfer member 5, the yellow toner image of the color is formed by an electric field and pressure generated by a primary transfer bias applied from the power source 14 to the intermediate transfer member 5. The image is transferred to the outer peripheral surface of the transfer body 5. Hereinafter, this process is called primary transfer. Note that the polarity of the primary transfer bias is opposite to the polarity of the toner.

Thereafter, similarly, the magenta toner image of the second color, the cyan toner image of the third color, and the black toner image of the fourth color are sequentially superimposed and transferred onto the intermediate transfer member 5 to form a desired full-color image. .

Reference numeral 6 denotes a transfer belt, which is mounted in parallel with the intermediate transfer member 5 so as to contact the lower surface. The transfer belt 6 includes a bias roller 62 and a tension roller 6.
1, a desired secondary transfer bias is applied to the bias roller 62 by the power supply 7, and the tension roller 61 is grounded.

The bias roller 62 and the tension roller 61 supporting the transfer belt 6 may be made of the same material or other materials.

The transfer of the full-color image superimposedly transferred on the intermediate transfer member 5 to the transfer material P, which is the second image carrier, is performed while the transfer belt 6 is in contact with the intermediate transfer member 5.
The transfer material P is fed at a predetermined timing from a paper feed cassette (not shown) through a registration roller 11 and a pre-transfer guide 10 to a contact nip between the intermediate transfer body 5 and the transfer belt 6, and at the same time, a secondary transfer bias is applied. Is applied from the power source 7 to the bias roller 62. Hereinafter, this process is called secondary transfer.

The transfer material P on which the toner image has been transferred is introduced into the fixing device 13 and is fixed by heating.

After the image transfer to the transfer member P is completed, the transfer residual toner on the intermediate transfer member 5 is cleaned. 8 is a cleaning roller, 81 is a cored bar, 82 is an elastic layer, 83 is a coating layer, and 9 is a power supply. Reference numeral 12 denotes a photosensitive drum cleaner. In the primary transfer step, the transfer belt 6 and the cleaning roller 8 are separated from the intermediate transfer body 5.

The cleaning of the intermediate transfer member will be described in more detail. This example is a simultaneous primary transfer cleaning in which the secondary transfer residual toner on the intermediate transfer member is transferred to the photosensitive drum and returned simultaneously with the primary transfer from the photosensitive drum to the intermediate transfer member.

The mechanism will be described. The secondary transfer residual toner receives an electric field having a polarity opposite to that of the toner at the time of the secondary transfer, and is often charged to a polarity (positive) opposite to a normal charging polarity (negative polarity in this example). However, not all toners are charged to a positive polarity, and there are toners that are neutralized and have no charge and toners that maintain a negative polarity. Therefore, even if the cleaning is performed as it is, it does not completely return to the photosensitive drum, and causes a ghost in the next print image in continuous printing. If the transfer bias is higher than the optimum transfer bias, image deterioration due to excessive transfer current occurs, and a high-definition image cannot be obtained.

Therefore, a charging means for inverting the neutralized toner having no charge or the toner maintaining the negative polarity to the opposite polarity is provided after the secondary transfer, and the transfer residual toner is uniformly charged to the opposite polarity. And the image is returned to the photoconductor at the same time as the primary transfer. FIG. 7 shows a schematic diagram of the primary transfer site in the present invention.

In this embodiment, as the secondary transfer residual toner charging means, a contact type charging means, specifically, a cleaning roller which is an elastic roller having a plurality of layers is used. The actual resistance of this roller was 6 × 10 ⁸ Ω.

[0086]

The present invention will be described in detail below with reference to examples. In the examples, “parts” indicates “parts by weight”.

Example 1 After extruding a rubber compound having the following composition, the diameter was 182 mm and the length was 320 m.
m, a roller (1) having a 5 mm-thick elastic layer was obtained by adhering to the surface of a 3 mm-thick aluminum cylindrical roller.

NBR 35 parts Epichlorohydrin rubber 65 parts Paraffin oil 2 parts Calcium carbonate 12 parts Vulcanizing agent 2 parts Vulcanization aid 2 parts Vulcanization accelerator 3 parts

The actual resistance of the rubber roller when 1 kV was applied was 9 × 10 ⁵ Ω.

Next, a surface layer paint having the following formulation was prepared.

DMF (dimethylformamide) solution of polyester polyurethane (solid content 20%) 100 parts Ethyl acetate solution of isocyanate trimer (solid content 75%) 4 parts Organometallic catalyst 0.04 parts PTFE powder (particle size 0) .3 μm) 37 parts Dispersing aid 1.8 parts Cyclohexanone 100 parts

This coating material was spray-coated on the surface of the roller (1), and then heated at 80 ° C. for 1 hour.
The remaining solvent is removed by heating for another 2 hours at
The curing agent was sufficiently reacted to form a surface layer having a thickness of 15 μm. The contact angle between this surface layer and water was 102 °. While rotating the intermediate transfer member, the fur brush, which was also driven to rotate, was brought into contact, and the contact portion was subjected to hydrophobic treatment with silica particles (particle diameter: 0.007 μm, hydrophobicity: 98).
%) To produce an intermediate transfer member (1) having transfer auxiliary particles (silica particles) on the surface. When the adhesion strength of the transfer assisting particles was evaluated by the method described above, the removal rate was 71%.
%Met.

This intermediate transfer member was incorporated in a laser printer having the structure shown in FIG. Each condition is as follows. The contact pressure of the intermediate transfer body 5 against the photosensitive drum 1 is 9
kgf. The contact pressure of the intermediate transfer member cleaning roller 8 against the intermediate transfer member 5 is 1 kgf. The contact pressure of the transfer belt 6 against the intermediate transfer member 5 is 3.5 kgf.

Dark part potential (non-image part potential on photosensitive drum due to primary charging): Vd = -580V Light part potential (image part potential on photosensitive drum by laser exposure): V1 = -150V Developing method: Non-magnetic one-component jumping Developed toner: Non-magnetic one-component toner having an average particle diameter of 6.8 μm obtained by dry mixing 1.2% by weight of the same silica as the intermediate transfer member. Developing bias: Vdc = −400 V Vac = 1600
V _PP , frequency = 1800 Hz Process speed: 120 mm / sec Primary transfer bias: +150 V The bias applied to the cleaning roller was adjusted to be optimal and variable, and a DC voltage with an AC voltage superimposed thereon was used.

The print test was performed in an N / N environment (23 ° C./60
% RH) and an H / H environment (30 ° C./80% RH), a horizontal line having a width of 1 mm in which two colors of magenta and cyan are overlapped with an interval of 2
After continuously printing three A3 images arranged at 0 mm, the images were changed to vertical lines with a width of 0.2 mm and intervals of 1 mm, and again printed in the same color. This image was used to visually check for negative ghosts and cleaning defects. Confirmed. As a result, good images having no problem were obtained in both environments. Furthermore,
Thereafter, the image pattern was changed to a character having a printing ratio of 5%, and printing of 10,000 A3 sheets in full color was continuously performed. Thereafter, the same print test and visual observation of the surface of the intermediate transfer member as in the initial stage were performed again. As a result, an image having no problem was obtained in both environments. And that the durability was good.

(Example 2) The transfer assisting particles had a particle size of 0.05.
μm, titania having a hydrophobicity of 60% was used, and the external additive of the developer was 0.9% by weight of the silica of Example 1 and 0.1% of the above titania.
Changed to 3% by weight. The removal rate was 63%. Other than that, the production of the intermediate transfer member and the print test were performed in the same manner as in Example 1. As a result, good results were obtained as in Example 1. Table 1 shows the results.

Example 3 The size of the transfer assisting particles was 0.06.
The alumina was changed to alumina having a hydrophobicity of 50% and the developer was changed to 1.0% by weight of the silica of Example 1 and 0.2% by weight of the alumina. The removal rate was 58%. Other than that, the production of the intermediate transfer member and the print test were performed in the same manner as in Example 1. As a result, good results were obtained as in Example 1. Table 1 shows the results.

Example 4 The size of the transfer assisting particles was 0.2 μm.
m, silica having a hydrophobicity of 80%. 73% removal rate
Met. Other than that, the production of the intermediate transfer member and the print test were performed in the same manner as in Example 1. As a result, good results were obtained as in Example 1. Table 1 shows the results.

Example 5 The surface layer paint of the intermediate transfer member was changed to the following composition. Otherwise, an intermediate transfer member was manufactured in the same manner as in Example 1. The contact angle of the transfer surface of the intermediate transfer member was 68 °. The removal rate was 55%.

Polyester polyurethane DMF (dimethylformamide) solution (solid content 20%) 100 parts Isocyanate trimer in ethyl acetate solution (solid content 75%) 4 parts Organometallic catalyst 0.04 parts PTFE powder (particle size 0) .3 μm) 15 parts Dispersing aid 1 part Cyclohexanone 15 parts

A print test was performed in the same manner as in Example 1. As a result, a very slight negative ghost was recognized in the initial print test in the H / H environment. Table 1 shows the results.

Example 6 The following rubber compound was extruded into a seamless belt having a diameter of 185 mm, a length of 320 mm and a thickness of 1.2 mm to obtain an elastic layer.

NBR 45 parts EPDM 65 parts Conductive carbon black 10 parts Paraffin oil 10 parts Calcium carbonate 7 parts Vulcanizing agent 2 parts Vulcanization aid 2 parts Vulcanization accelerator 3 parts

The coating material of Example 1 was dipped on the belt-like elastic layer to apply a surface layer, and heated at 80 ° C. for 30 minutes.
The coating was dried and cured by heating at 120 ° C. for 2 hours to obtain a belt-shaped intermediate transfer member having a surface layer having a thickness of 20 μm. The belt was rotated through an aluminum core bar, and the same silica fine particles were applied in the same manner as in Example 1. The removal rate was 70%.

This intermediate transfer member was mounted on the apparatus shown in FIG. 2, and a print test was performed in the same environment as in Example 1. The intermediate transfer belt drive roller, tension roller, transfer roller, and the like of this apparatus are designed to have a diameter of 60 mm or more in order to suppress damage to the intermediate transfer member due to roller bending. As a result, no poor cleaning or negative ghost was observed in the initial image, which was a good result. Further, a continuous full-color print test of 10,000 A3 sheets was performed. As a result, there was no cracking or peeling of the surface layer of the intermediate transfer member, and the image was good without any problem caused by cleaning of the intermediate transfer member. Table 1 shows the results.

Example 7 The following materials were melted and kneaded, then formed into a sheet, and the ends were bonded to each other to have a diameter of 185 m.
m, a length of 320 mm, and a thickness of 0.2 mm were obtained.

Fluorinated terpolymer 100 parts Conductive carbon black 5 parts

The belt was coated with fine silica particles in the same manner as in Example 6 to obtain a single-layer resin belt-shaped intermediate transfer member. The removal rate was 88%.

Using this intermediate transfer member, a print test was performed using the same apparatus and method as in Example 6. As a result, H /
A slight negative ghost and poor cleaning occurred mainly in the H environment. Further, very small cracks were observed at the end of the belt after durability. However, these were all minor. Table 1 shows the results.

(Embodiment 8) The transfer assisting particles had a particle size of 0.6 μm.
m, magnesia having a hydrophobicity of 90% and a removal rate of 82 in the same manner as in Example 6 except that a sponge roller was used.
% Of a belt-shaped intermediate transfer member. Using this intermediate transfer member, a print test was performed using the same apparatus and method as in Example 6, and good results were obtained as in Example 6. Table 1 shows the results.

Example 9 In Example 6, the silica was changed to titania having a particle size of 0.3 μm and a hydrophobicity of 48%, the contact strength of the fur brush when adhering was reduced, and the supply amount was increased. Then, a belt-shaped intermediate transfer member having weak adhesion strength of the transfer assisting particles was prepared. The removal rate was 92%. When a print test was performed using this intermediate transfer belt in the same manner as in Example 6, very slight negative ghosts and poor cleaning occurred in both environments from the beginning. After endurance, negative ghost and poor cleaning in H / H environment
In the / N environment, cracks occurred at the end of the belt, but all were slight. Table 1 shows the results.

Example 10 In Example 5, the transfer assisting particles were changed to silica having a particle size of 0.01 μm and a hydrophobicity of 50%, and the adhesion method was strongly rubbed using a solid rubber roller to strengthen the particles. To obtain an intermediate transfer member having a removal rate of 31%. When a print test was performed using this intermediate transfer member in the same manner as in Example 5, a slight negative ghost and poor cleaning occurred in both environments.
After the durability test, the N / N cleaning failure was improved, but the others were still generated, but all were slight. Table 1 shows the results.

(Example 11) The silica particles used in Example 1 were mixed at 5% by weight in acetone, and immediately after the surface layer was spray-coated in Example 1, this acetone-silica mixed solution was spray-coated, followed by surface coating. Was heat-cured to obtain an intermediate transfer member on which transfer assisting particles were multi-layered by wet continuous coating. When the surface of the intermediate transfer member was polished with a # 1500 abrasive paper and silica was completely removed, the contact angle of the surface layer was 102.
° and the particle removal rate was 41%.

A print test similar to that in Example 1 was performed using this intermediate transfer member, and good results were obtained. Table 1 shows the results.

(Example 12) Intermediate transfer was carried out in the same manner as in Example 1 except that the transfer auxiliary particles to be attached to the intermediate transfer member were changed to magnesium oxide having a particle diameter of 3.8 µm and a hydrophobicity of 85%. Created body. Using this intermediate transfer member, a print test similar to that of Example 1 was performed. As a result, slight cleaning defects and negative ghosts occurred in the initial H / H environment, and very slight cleaning defects also occurred in N / N. Even after the durability test, slight cleaning failure was observed in H / H. Table 1 shows the results.

(Comparative Example 1) An intermediate transfer member was prepared and a print test was performed in the same manner as in Example 5 except that no transfer auxiliary particles were used. As a result, in the H / H environment, the cleaning property of the intermediate transfer member was worse than at the beginning, and even if the cleaning current was changed, poor cleaning or negative ghost occurred, and there was no condition for obtaining a good image. For this reason, no durability test was performed. Table 1 shows the results.

(Comparative Example 2) An intermediate transfer member was prepared by attaching the same silica in the same manner as in Example 1 without forming a surface layer on the elastic layer of Example 1. The contact angle between the surface layer of this intermediate transfer member and water was 38 °, and the removal rate was 15%.

A print test similar to that of Example 1 was performed using this intermediate transfer member. As a result, both in the N / N environment and the H / H environment, the image density was lowered, the image was rough, and a remarkable cleaning defect was generated from the beginning. The durability test was not performed because the cleaning condition was not improved even when the cleaning conditions were changed. Table 1 shows the results.

[0119]

[Table 1]

[0120]

As described above, according to the present invention, it has excellent transfer performance even in a high temperature and high humidity environment from the beginning of use, has a long durable life, is easy to maintain, and can respond to high-speed printing. An image forming apparatus, an image forming method, and an intermediate transfer member can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an image forming apparatus of the present invention having a roller-shaped intermediate transfer member.

FIG. 2 is a schematic cross-sectional view of the image forming apparatus of the present invention having a belt-shaped intermediate transfer member.

FIG. 3 is an enlarged sectional view of a roller-shaped intermediate transfer member of the present invention.

FIG. 4 is an enlarged sectional view of a roller-shaped intermediate transfer member of the present invention.

FIG. 5 is an enlarged sectional view of a belt-shaped intermediate transfer body of the present invention.

FIG. 6 is an enlarged sectional view of a belt-shaped intermediate transfer member of the present invention.

FIG. 7 is a schematic diagram of primary transfer simultaneous intermediate transfer body cleaning.

Claims (42)

[Claims] 1. A first image carrier, and a toner image formed on the first image carrier is primarily transferred, and the transferred toner image is secondarily transferred on a second image carrier. An image forming apparatus having an intermediate transfer body for transferring, wherein a contact angle between a surface layer of the intermediate transfer body and water is 50 to 120 °.
An image forming apparatus, wherein transfer assisting particles are attached to the surface layer. 2. The image forming apparatus according to claim 1, wherein the image forming apparatus has a cleaning unit that collects toner remaining on the intermediate transfer member after the secondary transfer, and the cleaning unit is an electric field cleaning unit. 3. The image forming apparatus according to claim 2, wherein the cleaning unit is a primary transfer simultaneous cleaning unit. 4. The method according to claim 1, wherein the contact angle is 60 to 110 °.
An image forming apparatus according to any one of claims 1 to 3. 5. The image forming apparatus according to claim 1, wherein the transfer auxiliary particles have a particle size of 0.001 to 3 μm. 6. The image forming apparatus according to claim 5, wherein the particle size is 0.001 to 1 μm. 7. The image forming apparatus according to claim 6, wherein the particle size is 0.005 to 1 μm. 8. The method according to claim 1, wherein the transfer auxiliary particles are inorganic particles.
An image forming apparatus according to any one of claims 1 to 7. 9. The image forming apparatus according to claim 1, wherein the transfer auxiliary particles are made of the same material as at least one of the external additives included in the toner. 10. The image forming apparatus according to claim 1, wherein the transfer auxiliary particles have a degree of hydrophobicity of 30% or more. 11. The method according to claim 1, wherein the degree of hydrophobicity is 40% or more.
0. An image forming apparatus according to 12. The image forming apparatus according to claim 1, wherein the intermediate transfer member has a drum shape.
12. The image forming apparatus according to any one of claims 1 to 11. 13. The image forming apparatus according to claim 1, wherein the intermediate transfer member has a belt shape.
12. The image forming apparatus according to any one of claims 1 to 11. 14. The image forming apparatus according to claim 1, wherein the first image carrier is an electrophotographic photosensitive member. 15. The image forming apparatus according to claim 1, which is a full-color image forming apparatus. 16. Image formation in which a toner image is primary-transferred from a first image carrier to an intermediate transfer member, and the transferred toner image is secondary-transferred from the intermediate transfer member to a second image carrier. An image forming method, wherein an intermediate transfer member having a surface layer having a contact angle of 50 to 120 ° with water and having transfer auxiliary particles adhered thereto is used as the intermediate transfer member. 17. The image forming method according to claim 16, further comprising a cleaning step of recovering the toner remaining on the intermediate transfer member after the secondary transfer, wherein the cleaning step is an electric field cleaning step. 18. The image forming method according to claim 17, wherein the cleaning step is a primary transfer simultaneous cleaning step. 19. The image forming method according to claim 16, wherein the contact angle is 60 to 110 °. 20. The image forming method according to claim 16, wherein the transfer auxiliary particles have a particle size of 0.001 to 3 μm. 21. The image forming method according to claim 20, wherein the particle size is 0.001 μm to 1 μm. 22. The image forming method according to claim 21, wherein the particle size is 0.005 to 1 μm. 23. The image forming method according to claim 16, wherein the transfer auxiliary particles are inorganic particles. 24. The transfer auxiliary particles are made of the same material as at least one kind of external additive of the toner.
The image forming method according to any one of the above. 25. The image forming method according to claim 16, wherein the transfer auxiliary particles have a degree of hydrophobicity of 30% or more. 26. The hydrophobization degree is 40% or more.
6. The image forming method according to 5. 27. The image forming apparatus according to claim 1, wherein the intermediate transfer member is in a drum shape.
27. The image forming method according to any one of 6 to 26. 28. The image forming apparatus according to claim 1, wherein the intermediate transfer member has a belt shape.
27. The image forming method according to any one of 6 to 26. 29. The image forming method according to claim 16, wherein the first image carrier is an electrophotographic photosensitive member. 30. The image forming method according to claim 16, which is a full-color image forming method. 31. A toner image formed on a first image carrier is primarily transferred, and the transferred toner image is secondarily transferred to a second image carrier.
An intermediate transfer member for secondary transfer to the intermediate transfer member of the above, wherein the intermediate transfer member has a contact angle with water of 50 to 120 °,
An intermediate transfer member having a surface layer to which transfer assisting particles are attached. 32. The intermediate transfer member according to claim 31, wherein the contact angle is 60 to 110 °. 33. The intermediate transfer member according to claim 31, wherein the transfer auxiliary particles have a particle size of 0.001 to 3 μm. 34. The intermediate transfer member according to claim 33, wherein the particle size is 0.001 to 1 μm. 35. The intermediate transfer member according to claim 34, wherein the particle size is 0.005 to 1 μm. 36. The intermediate transfer member according to claim 31, wherein the transfer auxiliary particles are inorganic particles. 37. The transfer auxiliary particles are made of the same material as at least one kind of external additive of the toner.
The intermediate transfer member according to any one of the above. 38. The intermediate transfer member according to claim 31, wherein the transfer auxiliary particles have a degree of hydrophobicity of 30% or more. 39. The method according to claim 3, wherein the degree of hydrophobicity is 40% or more.
9. The intermediate transfer member according to 8. 40. The intermediate transfer member is in the form of a drum.
40. The intermediate transfer member according to any one of 1 to 39. 41. The intermediate transfer member is belt-shaped.
40. The intermediate transfer member according to any one of 1 to 39. 42. The intermediate transfer member according to claim 31, wherein the first image carrier is an electrophotographic photosensitive member.