JP2002287532A - Image forming device and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the sticking of toner to a transfer belt so as to facilitate the peeling of the stuck toner, and to obtain a high-gradation and high-resolution image by improving the reproducibility of a thin line and gradation in the case of forming an image. SOLUTION: In this image forming device equipped with at least the toner T and a transfer belt 8, the content of wax in the toner T is 5 to 40% and the belt 8 has an oxide particle layer on its outermost surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming apparatus and an image forming method. More specifically, the present invention relates to an image forming apparatus and an image forming method suitable for use in a printer, an electrophotographic copying machine, a facsimile, and the like.

[0002]

2. Description of the Related Art In recent years, copying machines using electrophotography, FA
With the rapid spread of X and printers, the demand for high-definition images has increased.

In order to obtain a high-definition image, and particularly to improve gradation and resolution, it is conceivable to increase the number of dots during image exposure. In this case, the beam diameter is reduced and the number of output pulses is increased. However, in such high-density recording, the time required for exposing one dot is reduced. In such a case, the sensitivity of the conventional photoreceptor is insufficient, and the reproducibility of one dot is degraded, which does not lead to an improvement in gradation and resolution. As a method of solving this, it is conceivable to increase the light energy itself, but this causes problems such as light fatigue in the photosensitive layer.

As a method for solving the above-mentioned problem, Japanese Patent Application Laid-Open No. 3-37678 discloses that the Bragg angle 2θ of the X-ray diffraction spectrum with respect to CuKα characteristic X-ray (wavelength 1.541 °) is 27.2 ± 0.2 °. A crystalline oxytitanyl phthalocyanine showing a strong X-ray intensity peak at
A method for use as a photoconductive substance in a photosensitive layer is disclosed. By using this oxytitanyl phthalocyanine, it is possible to realize a photoreceptor having high sensitivity, high γ and sufficient photoresponse, and using this photoreceptor, even when the exposure time of each dot is short at high density recording, sufficient. It is shown that a high dot reproducibility can be realized.

The publication discloses that a toner having an average particle diameter of 8 μm or less is used in combination, but in practice, the above-mentioned problem is not always sufficient if the toner has only a small particle diameter. Is not resolved. That is, although there is no specification in the same gazette for the intermediate transfer step and the transport transfer step, which are one step in the electrophotographic forming process, the adhesion of the toner to the intermediate transfer member and the transport transfer member is reduced and the toner is fixed. This is because a high-definition image cannot be maintained unless there is a device or a method for easily separating the toner.

Conventionally, members for intermediate transfer and transport in OA equipment such as electrophotographic copying machines, printers, and faxes are made of conductive resin compositions obtained by blending conductive carbon with polyester or polycarbonate. Seamless belts are used.

[0007] In such a seamless belt, the adhesion and detachment of the toner are repeated in the equipment, but if the adhesion and detachment are repeated for a long period of time, the toner may adhere to the surface of the seamless belt, and as a result, the image quality is degraded. There is a problem that it causes a decrease. Therefore, conventionally, a lubricant such as zinc stearate is applied to the belt surface so that the toner hardly adheres, or a resin having a low surface energy such as a fluororesin is used as a material of the seamless belt.

[0008] However, on the surface of the belt coated with zinc stearate, the adhered toner peels off, but the surface energy of the fatty acid metal salt is large, so that the adherence itself cannot be reduced. is there. In addition, when a seamless belt made of a material having a small surface energy such as a fluororesin is used, the surface energy is small, so that the fixation can be reduced. However, there is a problem that the toner once fixed does not easily come off.

Therefore, no matter how high the sensitivity and the high the photoreceptor, even if the photoreceptor has high sensitivity and high γ, it is not always necessary to reduce the adhesion of the toner to the intermediate transfer member and the conveyance transfer member and to make the adhered toner easy to peel off. High-resolution latent images cannot be obtained on the body.

Further, as for toner particles, those having a wax content as high as 5% or more may be used in order to improve the fixing property. There is a problem that the toner is easily leached, and as a result, sticking to the transfer member is likely to occur.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in the prior art.
That is, an object of the present invention is to reduce sticking of the toner to the transfer belt, facilitate the peeling of the sticked toner, and improve the reproducibility of fine lines and gradation at the time of forming an image. An object of the present invention is to provide an image forming apparatus and an image forming method that enable obtaining an image having a resolution.

[0012]

Means for Solving the Problems As a result of intensive studies in view of the above problems, the present inventors have found that the above problems can be solved by a combination of a toner having a specific structure and a transfer belt, and have reached the present invention. .

That is, the gist of the present invention is an image forming apparatus provided with at least a toner and a transfer belt, wherein the toner has a wax content of 5 to 40%, and the transfer belt has oxide particles on its outermost surface. An image forming apparatus having a layer.

Another aspect of the present invention is to provide a photoreceptor which is subjected to digital image exposure, and the electrostatic latent image on the photoreceptor formed by the image exposure is exposed to a wax having a wax content of 5 to 40.
% Of the toner image on the photoreceptor obtained by the development, and transferring the toner image on the photoconductor onto an intermediate transfer belt having an oxide particle layer on the outermost surface. Exist.

Further, another gist of the present invention is to perform digital image exposure on a photoreceptor, and to form an electrostatic latent image on the photoreceptor formed by the image exposure on a wax content of 5 to 40.
% Of the toner image, the toner image on the photoconductor obtained by the development is transferred to a sheet, and the sheet is transported by a transport transfer belt having an oxide particle layer on the outermost surface. And an image forming method.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an outline of a photoreceptor cartridge of the present invention and an electrophotographic apparatus (image forming apparatus) provided with the same will be described.
An electrophotographic apparatus using a component-based toner will be described, but the present invention is not limited to this example. In the following description, an electrophotographic apparatus may be referred to as an electrophotographic recording apparatus.

FIG. 1 is a schematic view showing a main part of an embodiment of an electrophotographic apparatus used in the present invention. The electrophotographic apparatus includes a photosensitive member 1, a charging device 2, an exposure device 3, and a developing device. The apparatus includes a device 4, a primary transfer device 5, a cleaning device 6, a fixing device 7, an intermediate transfer belt 8, and a secondary transfer device 9.

Here, the photosensitive member 1 is a cylindrical member made of a conductor such as aluminum, for example, and has a photosensitive layer formed by applying a photosensitive conductive material on the outer peripheral surface. A charging device 2, an exposure device 3, a developing device 4, a primary transfer device 5, a cleaning device 6, and an intermediate transfer belt 8 are arranged along the outer peripheral surface of the photoreceptor 1.

The charging device 2 charges the photoconductor 1 in contact with or close to the photoconductor 1, and uniformly charges the surface of the photoconductor 1 to a predetermined potential.

Here, the photosensitive member 1 and the charging device 2 are often designed as a cartridge having both of them (hereinafter, referred to as a photosensitive member cartridge) so as to be detachable from the main body of the electrophotographic apparatus. Then, for example, the photoconductor 1
When the charging device 2 is deteriorated, the photoreceptor cartridge can be removed from the main body of the electrophotographic apparatus, and another new photoreceptor cartridge can be mounted on the main body of the electrophotographic apparatus. In many cases, the toner is also stored in a toner cartridge and is designed to be removable from the main body of the electrophotographic apparatus. When the toner in the cartridge runs out, the toner cartridge is removed from the main body of the electrophotographic apparatus. And another new toner cartridge can be installed.
Further, a cartridge provided with all of the photoconductor 1, the charging device 2, and the toner is also used.

The exposure device 3 includes an LED on the photosensitive surface of the photosensitive member 1.
This is to form an electrostatic latent image on the photosensitive surface of the photoreceptor 1 by performing exposure with a laser beam or the like. The developing device 4 includes a developing tank 41, an agitator 42, a supply roller 43, a developing roller 44, and a regulating member 45, and stores the toner T inside the developing tank 41. Further, a replenishing device (not shown) for replenishing the toner T may be attached to the developing device 4 as needed. This replenishing device is configured to be able to replenish the toner T from a container such as a bottle or a cartridge.

The supply roller 43 is formed from a conductive sponge or the like. The developing roller 44 is made of a metal roll of iron, stainless steel, aluminum, nickel, or the like, or a resin roll in which such a metal roll is coated with a silicon resin, a urethane resin, a fluorine resin, or the like. The surface of the developing roller 44 may be subjected to smoothing or roughening if necessary.

The developing roller 44 is disposed between the photosensitive member 1 and the supply roller 43, and is provided between the photosensitive member 1 and the supply roller 43.
Are in contact with each other. The supply roller 43 and the developing roller 44 are rotated by a rotation drive mechanism (not shown). The supply roller 43 carries the stored toner T and supplies it to the developing roller 44. The developing roller 44
The toner T supplied by the supply roller 43 is carried and brought into contact with the surface of the photoconductor 1.

The regulating member 45 is formed of a resin blade such as a silicone resin or a urethane resin, a metal blade such as stainless steel, aluminum, copper, brass, phosphor bronze, or a blade in which such a metal blade is coated with a resin. . The regulating member 45 is provided with the developing roller 44.
, And pressed against the developing roller 44 with a predetermined force by a spring or the like (a general blade linear pressure is 5 to 500 g / cm).
Is done. If necessary, toner T
May be provided with a function of charging the toner T by frictional charging with the toner T.

The agitator 42 is rotated by a rotation drive mechanism, and agitates the toner T and conveys the toner T to the supply roller 43 side. A plurality of agitators 42 may be provided with different blade shapes, sizes, and the like.

The primary transfer device 5 is disposed to face the photoconductor 1 with the intermediate transfer belt 8 interposed therebetween, and transfers the toner image formed on the photoconductor 1 onto the intermediate transfer belt 8. As the primary transfer device 5, an electrostatic transfer device is used, and a toner image is transferred onto the intermediate transfer belt 8 by applying a predetermined voltage value (transfer voltage) having a polarity opposite to the charged potential of the toner.

The intermediate transfer belt 8 absorbs the toner image transferred by the electrostatic transfer device 5 by electrostatic force,
An endless belt with and without a seam is used to transport the toner to the position of the secondary transfer device 9 and to repeatedly charge and remove the toner. The intermediate transfer belt 8 is stretched around conveying rollers 8a, 8b, 8c, and is indicated by an arrow A in FIG.
In synchronization with the photoreceptor 1 rotating in the direction, the photoreceptor 1 also moves in the direction of arrow B in FIG.

The cleaning device 6 includes a cleaning member such as a urethane blade or a fur brush. The cleaning device 6 scrapes residual toner adhered to the photoreceptor 1 by the cleaning member and collects the residual toner. is there.

The secondary transfer device 9 is disposed to face the transport roller 8c with the intermediate transfer belt 8 interposed therebetween, and transfers the toner image formed on the intermediate transfer belt 8 to recording paper (medium, paper) P
It is transferred to the top. As the secondary transfer device 9, for example, a pressing transfer roller is used, and the pressing transfer roller presses the recording paper P against the intermediate transfer belt 8 on which the toner image is formed, so that the intermediate transfer belt 8 Is transferred onto the recording paper P by pressure and electrostatic force.

The fixing device 7 is composed of an upper fixing member (fixing roller) 71 and a lower fixing member (fixing roller) 72. Inside the fixing member 71 or 72, a heating device 7 is provided.
Three are provided. FIG. 1 shows an example in which a heating device 73 is provided inside the upper fixing member 71. The upper and lower fixing members 71 and 72 are made of stainless steel,
Known fixing members such as a fixing roll in which a metal tube made of aluminum or the like is coated with silicon rubber, a fixing roll in which Teflon (registered trademark) resin is coated, a fixing sheet, and the like can be used. Further, each fixing member 71, 72
May be configured to supply a release agent such as silicone oil in order to improve the releasability, or may be configured to forcibly apply pressure to each other by a spring or the like.

The toner transferred onto the recording paper P by the secondary transfer device 9 is transferred to the upper fixing member 7 heated to a predetermined temperature.
When the toner passes between the first fixing member 72 and the lower fixing member 72, the toner is heated to a molten state, cooled after the toner is passed, and the toner is fixed on the recording paper P.

In the electrophotographic apparatus configured as described above, an image is recorded as follows. That is, first, the surface (photosensitive surface) of the photoconductor 1 is charged to a predetermined potential (for example, −600 V) by the charging device 2. continue,
The charged photosensitive surface of the photoconductor 1 is exposed by an exposure device 3 in accordance with an image to be recorded, and an electrostatic latent image is formed on the photosensitive surface. Then, the developing device 4 develops the electrostatic latent image formed on the photosensitive surface of the photosensitive member 1.

The developing device 4 reduces the thickness of the toner T supplied by the supply roller 43 by a regulating member (developing blade) 45, and also has a predetermined polarity (here, the photosensitive member 1).
Has the same polarity as the charged potential of
The sheet is transported while being carried on the developing roller 44, and is brought into contact with the surface of the photoconductor 1.

The charged toner T carried on the developing roller 44
Contacts the surface of the photoconductor 1, a toner image corresponding to the electrostatic latent image is formed on the photosensitive surface of the photoconductor 1 by a so-called reversal development method. Then, the toner image is transferred to the intermediate transfer belt 8 by the transfer device 5 and further transferred to the recording paper P by the secondary transfer device 9. Thereafter, the toner remaining on the photosensitive surface of the photoconductor 1 without being transferred is removed by the cleaning device 6.

After the transfer of the toner image onto the recording paper P, the final image is obtained by passing the toner image through the fixing device 7 and thermally fixing the toner image onto the recording paper P.

Next, an example of a tandem type electrophotographic apparatus (image forming apparatus) using a non-magnetic one-component toner as a full color will be described. FIG. 2 is a schematic view showing a main part of an embodiment of a full-color tandem type electrophotographic apparatus used in the present invention, and includes a photosensitive member 1, a charging device 2, an exposing device 3, a black developing device 4k, and a cyan developing device. Device 4c, yellow developing device 4y, magenta developing device 4m, transfer device 5, fixing device 7, and transfer belt 1
0, and the cleaning device is omitted here. In this electrophotographic apparatus, a color image can be obtained by adjusting each of the toners Tk, Tc, Ty, and Tm of magenta, yellow, cyan, and black to a desired color by superposing them in multiple layers.

In FIG. 2, the same reference numerals as those in FIG. 1 denote the same or almost the same parts, and a description thereof will be omitted. The developing devices 4k, 4c, 4y and 4m
Are constructed in the same manner as the developing device 4 of FIG. 1, and perform development with toners Tk, Tc, Ty and Tm corresponding to each color. The transfer device 5 is disposed opposite to the corresponding photoconductor 1 with the transport transfer belt 10 interposed therebetween, and transfers the toner image formed on the photoconductor 1 onto the recording paper P on the transport transfer belt 10. A device having the same configuration as the primary transfer device 5 and the secondary transfer device 9 in FIG. 1 is used. The transfer belt 10 is provided with each photoconductor 1 corresponding to each color.
The recording paper P is conveyed to the fixing device 7 while passing between the transfer device 5 and each of the transfer devices 5.

In the case of the tandem system, cyan, yellow,
When the magenta color developing section is located before (on the upstream side of) the black developing section, color mixing due to reverse transfer of the black toner is reduced. Further, when the black developing unit is located behind (downstream side) the color developing unit, the color mixture due to the photoconductor fog of the color toner is reduced when an image is formed in a single color of black only. In this case, the speed of image formation can be increased by conveying the recording paper P through a short pass of the color developing section. Therefore, when the image forming method of the present invention is applied to full-color image formation, the electrophotographic apparatus should be configured such that the color developing unit is located at the front and the black developing unit is located at the back as shown in FIG. Is preferred. In addition,
The order in which the cyan, magenta, and yellow color developing units are located can be freely changed as appropriate.

In the above-described full-color tandem-type electrophotographic apparatus, an intermediate transfer belt 8 as shown in FIG. 1 is interposed between each photoreceptor 1 corresponding to each color and the transfer belt 10. The toner image formed on each photoreceptor 1 is primarily transferred onto an intermediate transfer belt, and then transported to the position of the transport transfer belt 10 so that the toner image is secondarily transferred onto the recording paper P on the transport transfer belt 10. It may be configured to transfer.

[Photoconductor] Next, the photoconductor (see reference numeral 1 in FIGS. 1 and 2) used in the present invention will be described.

The photoreceptor used in the present invention has a photosensitive layer on a conductive support, and is preferably a laminated photoreceptor in which a charge generation layer and a charge transfer layer are laminated. Usually, the charge generation layer and the charge transfer layer preferably have a configuration in which the charge transfer layer is laminated on the charge generation layer, but may have the opposite configuration.

In addition to these, a layer for improving electric and mechanical characteristics such as an intermediate layer such as an adhesive layer and a blocking layer and a protective layer may be provided. As the conductive support,
Any of the well-known electrophotographic photosensitive members can be used.

Specific examples of the conductive support include metal drums and sheets of aluminum, stainless steel, copper, etc., and laminates and vapor-deposits of these metal foils. Further, plastic films, plastic drums, paper, paper tubes, and the like, which are subjected to conductive treatment by applying a conductive substance such as metal powder, carbon black, copper iodide, and polymer electrolyte together with a suitable binder, may be mentioned. In addition, a plastic sheet or drum containing a conductive material such as metal powder, carbon black, and carbon fiber and made conductive may be used. Further, a plastic film or a belt which has been subjected to a conductive treatment with a conductive metal oxide such as tin oxide or indium oxide may be used.

The charge generating layer contains at least a binder polymer and a charge generating agent, and may further contain an organic photoconductive compound, a dye, an electron withdrawing compound, and the like, if necessary.

As the charge generation material used in the present invention, known materials can be used, but a phthalocyanine compound is preferable in terms of sensitivity. In particular, when exposure with a laser beam of 650 to 850 nm is performed, α-type, β type, Y
Oxytitanium phthalocyanines of the type and the like are preferred.

Examples of the binder used in the charge generation layer include polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylates, methacrylates, vinyl alcohol, and ethyl vinyl ether, polyvinyl acetal, and polycarbonate. , Polyester, polyamide, polyurethane, cellulose ester, cellulose ether, phenoxy resin, silicon resin, epoxy resin and the like. The ratio of oxytitanium phthalocyanine to binder polymer is not particularly limited, but generally, 5 to 500 parts by weight, preferably 20 to 300 parts by weight, of binder polymer is used per 100 parts by weight of oxytitanium phthalocyanine.

The thickness of the charge generation layer is 0.05 to 5 μm,
Preferably it is 0.1 to 2 μm. Charge carriers are injected from the charge generation layer. The charge transfer layer contains a carrier transfer medium (charge transfer agent) having high carrier injection efficiency and transfer efficiency.

The charge transfer layer contains at least a binder and a charge transfer agent, and if necessary, various additives such as an antioxidant, a sensitizer, a plasticizer, a fluidity imparting agent, and a crosslinking agent. May be included.

As the charge transfer agent, as a high molecular compound, a high molecular compound having a heterocyclic compound such as poly-N-vinylcarbazole or polystyrylanthracene or a condensed polycyclic aromatic compound in a side chain, or a low molecular compound , Pyrazoline, imidazole, oxazole, oxadiazole, triazole, carbazole and other heterocyclic compounds,
Examples thereof include triarylalkane derivatives such as triphenylmethane, triarylamine derivatives such as triphenylamine, phenylenediamine derivatives, N-phenylcarbazole derivatives, stilbene derivatives, and hydrazone compounds. Examples thereof include compounds having a large electron donating property, which are substituted by an electron donating group such as a group or an aromatic ring group having these substituents.

Among these, the following formula (1), formula (2), formula (3), formula (4) or formula (5)
A compound having an atomic group represented by

Embedded image Equation (1)

[0051]

Embedded image Equation (2)

[0052]

Embedded image Equation (3)

[0053]

Embedded image Equation (4)

[0054]

Embedded image Equation (5)

The binder used in the charge transfer layer is preferably a polymer which has good compatibility with the above-mentioned charge transfer agent and does not crystallize or phase-separate the carrier transfer medium after the formation of the coating film. Are polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylic acid ester, methacrylic acid ester, butadiene, polyvinyl acetal, polycarbonate, polyester, polysulfone, polyphenylene oxide, polyurethane, cellulose ester, cellulose ether Phenoxy resin, silicon resin, epoxy resin and the like. Among them, a polyester resin is preferable from the viewpoint of durability, and a polycarbonate resin is preferable from the viewpoint of electric characteristics.

When the charge transfer agent is a polymer compound, it is not particularly necessary to use a binder polymer, but mixing may be carried out to improve flexibility. In the case of a low-molecular compound, a binder polymer is used for film-forming properties, and the amount used is usually in the range of 50 to 1000 parts by weight, preferably 100 to 500 parts by weight, per 100 parts by weight of the charge transfer material. . In addition to the above, various additives for improving the mechanical strength and durability of the coating film can be used in the charge transfer layer. Examples of such additives include well-known plasticizers, various stabilizers, flowability-imparting agents, and crosslinking agents.

[Toner] Next, the toner used in the present invention (reference T in FIG. 1 and reference Tk, Tc, Ty, Tm in FIG. 2)
Reference) will be described. The toner of the present invention contains at least a binder resin (binder resin), a colorant and a wax, and is characterized in that the content of the wax is 5 to 40%. Further, in addition to these components, a charge control agent and other additives may be included as necessary.

As a method for producing the toner used in the present invention, there are a method for increasing the accuracy of a classifier in a conventional pulverized toner and a method for producing the toner by a wet polymerization method such as a suspension polymerization method and an emulsion polymerization aggregation method. However, in order to efficiently produce the toner having a high wax content used in the present invention, a wet polymerization method is preferable. Above all, it is more preferable to use the emulsion polymerization aggregation method because the toner having the particle diameter and circularity of the present invention can be efficiently produced and the particle size distribution can be easily controlled.

The binder resin used for the toner can be selected from a wide range including conventionally known ones. Preferably, a styrene-based polymer such as a styrene-acrylate copolymer, a styrene-methacrylate copolymer or an acrylic copolymer of these resins, a saturated or unsaturated polyester-based polymer, or an epoxy-based polymer is used. Can be. Further, the binder resin is not limited to being used alone, and two or more kinds may be used in combination.

The colorant used in the toner includes inorganic pigments,
Any of an organic pigment and an organic dye may be used, or a combination thereof may be used. Specific examples of these include carbon black, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa Yellow,
Rhodamine dyes, chrome yellow, quinacridone,
Any known dyes or pigments such as benzidine yellow, rose bengal, triallylmethane dyes, monoazo dyes, disazo dyes and condensed azo dyes can be used alone or in combination. In the case of a full-color toner, it is preferable to use benzidine yellow, a monoazo-based or condensed azo-based dye / pigment as yellow, quinacridone / monoazo-based dye / pigment as magenta, and phthalocyanine blue as cyan, respectively.

Among the above, as the cyan coloring agent,
C. I. Pigment Blue 15: 3 and yellow colorants include C.I. I. Pigment yellow 74, C.I. I. Pigment Yellow 93 and magenta colorants include C.I.
I. Pigment Red 238, C.I. I. Pigment Red 269, C.I. I. Pigment Red 57: 1, C.I.
I. Pigment Red 48: 2, C.I. I. Pigment Red 122 and the like are each preferable. The amount of the colorant added is preferably in the range of 2 to 25 parts by weight based on 100 parts by weight of the binder resin.

A charge controlling agent may be added to the toner used in the present invention in order to make the charge amount uniform and to impart charge stability. Any known charge control agent can be used alone or in combination. For example, a quaternary ammonium salt, a metal complex of a hydroxycarboxylic acid, a metal complex of an azo compound, a nigrosine dye, a naphthol compound, a metal salt thereof, and a mixture thereof are exemplified. The amount used may be determined depending on the desired charge amount for the toner, but usually, the amount of the binder resin
0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, is used relative to 0 parts by weight.

The toner of the present invention is characterized in that it contains wax at a concentration of 5 to 40% in order to improve the releasability from the fixing roller. Any known wax can be used, and specific examples thereof include olefin waxes such as low molecular weight polyethylene, low molecular weight polypropylene, and copolymerized polyethylene; paraffin wax; behenyl behenate, montanic acid ester, stearyl stearate and the like. Ester waxes having a long-chain aliphatic group; vegetable waxes such as hydrogenated castor oil carnauba wax; ketones having a long-chain alkyl group such as distearyl ketone; silicones having an alkyl group; higher fatty acids such as stearic acid; Long-chain aliphatic alcohols; carboxylic acid esters or partial esters of polyhydric alcohols obtained from long-chain fatty acids and polyhydric alcohols such as glycerin and pentaerythritol; higher fatty acid amides such as oleamide and stearamide; low molecular weight Riesuteru like.

In order to improve the fixability of the toner to which these waxes are added, the melting point of the wax is preferably 30 ° C. or higher, more preferably 40 ° C. or higher, and particularly preferably 50 ° C. or higher. Further, the temperature is preferably 100 ° C. or lower, more preferably 90 ° C. or lower, and particularly preferably 80 ° C. or lower. If the melting point is too low, the wax is exposed to the surface after fixing, and stickiness tends to occur. If the melting point is too high, the fixability at low temperatures is inferior.
Further, as the compound type of the wax, an ester wax obtained from an aliphatic carboxylic acid and a monohydric or polyhydric alcohol is preferable, and among the ester waxes, those having 20 to 100 carbon atoms are more preferable. Those having 30 to 60 are particularly preferred.

Particularly preferred compounds among esters of a monohydric alcohol and an aliphatic carboxylic acid include behenyl behenate and stearyl stearate. Particularly preferable compounds among esters of polyhydric alcohol and aliphatic carboxylic acid include stearic acid ester of pentaerythritol and its partial ester, montanic acid ester of glycerin and its partial ester. The waxes may be used alone or as a mixture. Further, the melting point of the wax compound can be appropriately selected depending on the fixing temperature at which the toner is fixed.

The amount of the wax added is usually 0.1 to 40% by weight, preferably 1 to 40% by weight, more preferably 5 to 35% by weight, and particularly preferably 7 to 30% by weight in the toner. If a suspension polymerization method or an emulsion polymerization aggregation method is used, a large amount of 5 to 40% by weight can be added. Therefore, a large amount may be added as necessary.

Next, a wet polymerization method will be described as a preferred method for producing the toner used in the present invention. First,
When the toner for developing an electrostatic image used in the present invention is obtained by an emulsion polymerization aggregation method, the colorant, the charge control agent, and the wax are used in the form of a dispersion. These can be obtained as follows. For example, each substance may be a nonionic surfactant represented by polyoxyethylene alkyl phenyl ether, an anionic surfactant represented by alkylbenzene sulfonate, or a cationic surfactant represented by quaternary ammonium salt. It can be produced by adding a surfactant and the like to water and using a mechanical pulverization method containing a medium and the like. Further, a water-soluble organic solvent may be added as needed. The dispersion diameter of each substance is 0.001 to 5 μm, preferably 0.01 to 5 μm.
１1 μm.

In the emulsion polymerization aggregation method, a colorant dispersion, a charge control agent dispersion, a wax dispersion and the like are mixed with a polymer emulsion, and the mixture is aggregated by appropriately controlling the temperature, salt concentration, pH, and the like. Manufacture toner. In the obtained toner, a surfactant or the like remains on the surface. In order to remove these, acid washing, alkali washing, water washing, and the like may be appropriately performed.

In the suspension polymerization method, a colorant,
A charge controlling agent, wax and the like are mixed, and a dispersion process is performed using a disperser or the like, and the monomer composition after the dispersion process is dispersed in a water-miscible medium using a suitable stirrer. After granulating to a diameter, the polymerizable monomer is polymerized to produce a toner.

When a suspension stabilizer is used, the toner can be easily removed by acid washing after polymerization.
It is preferable to select one that exhibits neutrality or alkalinity in water. Further, it is preferable to select a toner capable of obtaining a toner having a narrow particle size distribution. Suspension stabilizers that satisfy these requirements include calcium phosphate, tricalcium phosphate, magnesium phosphate, calcium hydroxide, magnesium hydroxide and the like. Each can be used alone or in combination of two or more. These suspension stabilizers can be used in an amount of 1 to 10 parts by weight based on the radical polymerizable monomer.

As the polymerization initiator used in the emulsion polymerization aggregation method and the suspension polymerization method, known polymerization initiators can be used alone or in combination of two or more. For example, potassium persulfate, 2,2'-azobisisobutyronitrile, 2,2'-azobisiso (2,4-dimethyl)
Valeronitrile, benzoyl peroxide, lauroyl peroxide, or a redox initiator can be used. Among these, a redox initiator is preferable in the emulsion polymerization aggregation method, and an azo initiator is preferable in the suspension polymerization method. Among these, a redox initiator is preferred in the emulsion polymerization coagulation method, and an azo initiator is preferred in the suspension polymerization method.

After the toner is manufactured by the above method, a toner having a capsule structure is obtained by adding a polymer emulsion, a colorant dispersion, a charge control agent dispersion, a wax dispersion and the like to cover the toner surface. good. In particular, in order to keep the circularity and particle size distribution of the toner in a suitable range, it is preferable to employ an emulsion polymerization aggregation method as a method for producing the toner.

Further, in order to enhance the low-temperature fixing property and the releasability, the above-mentioned wax is usually used in an amount of 0.01 μm to 3 μm.
m, preferably 0.1 to 2 μm, more preferably 0.3
A dispersion of wax fine particles is prepared by using a surfactant so as to have a volume average particle size of about 1.5 μm, and a monomer mixture of styrene, acrylic acid, acrylate ester, etc. is added in the presence of the dispersion of wax fine particles. Is added, and emulsion polymerization is carried out (so-called wax seed polymerization) to contain a wax, usually 0.02 μm to 3 μm, preferably 0.05 μm to 3 μm, and more preferably 0.1 μm to 2 μm.
μm, particularly preferably to produce polymer primary particles having a volume average particle size of 0.1 μm to 1 μm, and aggregate the polymer primary particles containing the wax by adding an electrolyte, preferably the polymer The polymer primary particles are fused with each other while being maintained at a temperature higher than the glass transition temperature of the primary particles for a certain period of time to obtain toner particles having a volume average particle diameter of 3 to 8 μm.

A known external additive may be added to the toner for developing an electrostatic image used in the present invention in order to control fluidity and developability. As the external additive, various kinds of inorganic oxide particles such as silica, alumina, titania and the like (which may be subjected to a hydrophobic treatment if necessary), vinyl polymer particles and the like can be used. The amount of the external additive is preferably in the range of 0.05 to 5 parts by weight based on the toner particles.

The toner of the present invention can be applied to a magnetic one-component developer such as a two-component developer and a magnetite-containing toner, and a non-magnetic one-component developer. When the toner of the present invention is used as a two-component developer, a known magnetic substance such as an iron powder-based, ferrite-based, or magnetite-based carrier or a resin may be used as a carrier for forming a developer by mixing with the toner. A coated one or a magnetic resin carrier can be used.

As the coating resin for the carrier, generally known styrene resins, acrylic resins, styrene-acryl copolymer resins, silicone resins, modified silicone resins, fluorine resins and the like can be used. It is not limited. The average particle size of the carrier is not particularly limited, but preferably has an average particle size of 10 to 200 μm. These carriers are preferably used in an amount of 5 to 100 parts by weight based on 1 part by weight of the toner.

In the present invention, as a method of quantifying the shape of the toner, the toner is measured with a flow particle image analyzer FPIA-2000 manufactured by Sysmex Corporation, and the cumulative particle size at 50% of the value obtained from the following formula is measured. The circularity corresponding to the value is defined as 50% circularity. Circularity = Perimeter of a circle with the same area as the projected area of the particle / Perimeter of the projected image of the particle

The 50% circularity of the toner in the present invention is as follows:
Indicates the degree of unevenness of the toner particles, and is 1 when the toner is perfectly spherical. As the surface shape becomes more complicated, the value of the circularity decreases. The circularity of the toner used in the present invention is preferably 0.9 or more, more preferably 0.92 or more, and particularly preferably 0.95 or more. In addition, since it is difficult to produce a perfect sphere in production,
95 or less, more preferably 0.99 or less.

In the present invention, as a method for defining the particle size of the toner, a Coulter Counter, a precision particle size distribution measuring device manufactured by Beckman Coulter, Inc.
Use Multisizer II. The volume average particle diameter of the toner used in the present invention is preferably from 3 to 8 μm, more preferably from 4 to 7.5 μm, as measured by the Coulter counter.

Further, it is preferable that the particle size distribution of the toner is sharp, since the chargeability among the individual particles becomes uniform. Specifically, it is preferable that the relationship between the volume average particle size (D _V ) and the number average particle size (D _N ) satisfy 1.0 ≦ D _V / D _N ≦ 1.3.

For measuring fine particles of 0.6 μm to 2.12 μm, a flow type particle image analyzer FPIA-2000 manufactured by Sysmex Corporation is used. A toner in which the measured value (number) of particles of 0.6 μm to 2.12 μm measured by a flow type particle image analyzer is 15% or less of the total number of particles, and more preferably 10% or less. This means that the number of fine particles is smaller than a certain amount. However, when the number of fine particles is small, the fluidity of the toner is easily improved, and the chargeability is easily uniform.

[Intermediate Transfer Belt and Conveyance Transfer Belt]
Next, an intermediate transfer belt (see reference numeral 8 in FIG. 1) and a transfer belt (see reference numeral 10 in FIG. 1), which are transfer belts used in the present invention, will be described. The transfer belt of the present invention is formed as an endless belt with and without a seam. The material of the endless belt is not particularly limited, and a usual resin composition containing a conductivity-imparting agent can be used.

Here, examples of the conductivity-imparting agent include conductive carbon such as carbon black, various metal powders and the like. As the resin, ordinary engineering plastics can be used, but polyester, polycarbonate, polyamide and the like are preferable. Is mentioned. More specifically, a polycarbonate composition containing a conductive carbon described in JP-A-3-89357, and a polyalkylene terephthalate composition containing a conductive carbon described in JP-A-6-149081 Things etc. can be used suitably, respectively.

(Oxide particles) End used in the present invention
Resbelt features an oxide particle layer on the surface
And The oxide particles used in the present invention are not particularly limited.
In particular, metal oxides are preferred.
And more specifically, SiO_Two, Al_TwoO_Three, TiO_Two, Sn
O _TwoIt is preferable to use oxide particles such as ZnO and ZnO.
it can. Oxide particles to be used may be one kind,
These may be used in combination of two or more. Oxide
Although the surface condition of the particles is not particularly limited,
Hydrophobic surface further reduces toner sticking
That have been subjected to a hydrophobizing treatment.
No.

The method of the hydrophobizing treatment is not particularly limited, but as a particularly effective method, at least one functional group selected from an alkylsilyl group, a halogenated alkyl group, an alkoxyalkylsilyl group and an alkyl group is added to the surface of the oxide particle. To introduce. In order to introduce these functional groups onto the surface of the oxide particles, for example, a method of treating the oxide particles with a solution of an alcohol, silane, siloxane, titanium, or amine compound may be mentioned. Treatment with an alkoxyalkylsilane compound is particularly preferred.

The endless belt used in the present invention is:
It is preferred that the surface has a high contact angle with water, usually 90
The oxide particles subjected to the hydrophobizing treatment are selected so as to be at least 120 °, more preferably at least 120 °. There is no particular limitation on the particle size of the oxide particles, but when the image forming apparatus of the present invention is applied to an electrophotographic copying machine, image disorder may occur if the oxide particles are too large compared to the toner. Therefore, the average particle diameter is preferably 10 μm or less, more preferably 1 μm or less, which is sufficiently smaller than the toner, and 100 n
If m or less, it is particularly preferable since it hardly affects the image.

(Method of Forming Oxide Particle Layer) The oxide particle layer in the present invention is formed on an endless belt as an intermediate transfer belt and a transport transfer belt, but is not necessarily a continuous layer as long as the effects of the present invention are obtained. It doesn't have to be
It may be a discontinuous layer.

The method for forming the oxide particle layer on the endless belt is not particularly limited, and any known method can be employed.
A method in which the oxide particles are periodically supplied to the endless belt in the device A is exemplified.

Examples of the method of forming in advance include a method in which oxide particles are dispersed in a coating solvent, a binder, or the like, and are applied and sprayed on the surface of the endless belt. Can be selected from various methods, including a method of contacting the endless belt with an endless belt, a method of forming only an oxide particle layer with an oxide particle-containing binder composition, and then laminating the layer with an endless belt.

[0090]

EXAMPLES The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to the following examples. In the following examples, “parts” means “parts by weight”. The average particle size, weight average molecular weight, glass transition temperature (Tg) and 50% circularity are as follows:
Each was measured by the following method.

Average particle size: Measured using LA-500 manufactured by Horiba, Microtrac UPA manufactured by Nikkiso Co., Ltd., and Coulter Counter Multisizer II (abbreviated as Coulter Counter) manufactured by Coulter.

Weight average molecular weight (Mw): Measured by gel permeation chromatography (GPC) (apparatus: GPC apparatus HLC-8020 manufactured by Tosoh Corporation, column: PL-gel Mixed-B 10 μm manufactured by Polymer Laboratory, solvent: THF) , Sample concentration: 0.1% by weight, calibration curve: standard polystyrene).

Glass transition point (Tg): Measured by DSC7 manufactured by Perkin Elmer (heated from 30 ° C. to 100 ° C. in 7 minutes, rapidly cooled from 100 ° C. to −20 ° C., −2
The temperature was raised from 0 ° C. to 100 ° C. in 12 minutes, and the value of Tg observed at the second heating was used).

50% circularity: The toner was measured with a flow type particle image analyzer FPIA-2000 manufactured by Sysmex Corporation, and the circularity corresponding to the cumulative particle size value at 50% of the value obtained from the following equation was used. Circularity = Perimeter of a circle with the same area as the projected area of the particle / Perimeter of the projected image of the particle

[Production of toner for development-1] (Wax dispersion) 68.33 parts of demineralized water, 30 parts of an ester mixture mainly composed of stearic acid ester of pentaerythritol (Unistar H476, manufactured by NOF CORPORATION), dodecylbenzene sulfone Sodium salt (Neogen SC,
1.67 parts of an active ingredient (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was mixed and emulsified by applying high-pressure shear at 90 ° C. to obtain a dispersion of ester wax fine particles. The average particle size of the ester wax fine particles measured by LA-500 was 350 nm.

(Polymer Primary Particle Dispersion) 35 parts of the above wax dispersion and 39 parts of demineralized water were placed in a reactor equipped with a stirrer, a heating / cooling device, a concentrating device, and a device for charging raw materials and auxiliaries.
7 parts were charged, the temperature was raised to 90 ° C. under a nitrogen stream, and 1.6 parts of an 8% aqueous hydrogen peroxide solution and 1.6 parts of an 8% aqueous ascorbic acid solution were added.

Thereafter, a mixture of a monomer and an aqueous solution of an emulsifier having the composition shown in Table 1 below was added over 5 hours from the start of polymerization.
Similarly, an aqueous initiator solution having the composition shown in Table 1 below was added over a period of 6 hours from the start of the polymerization, and the mixture was held for another 30 minutes.

[Table 1]

After the completion of the polymerization reaction, the mixture was cooled to obtain a milky white polymer dispersion. The weight-average molecular weight of the THF-soluble component of the polymer is 139,000, and the average particle size measured by UPA is 2
01 nm and Tg were unclear.

(Resin Particle Dispersion) In a reactor equipped with a stirrer, a heating / cooling device, a concentrating device, and a device for charging raw materials and auxiliaries, 6 parts of 15% neogen SC aqueous solution,
2 parts were charged, the temperature was raised to 90 ° C. under a nitrogen stream, and 1.6 parts of an 8% aqueous hydrogen peroxide solution and 1.6 parts of an 8% aqueous ascorbic acid solution were added.

Thereafter, a mixture of a monomer / emulsifier aqueous solution having the composition shown in Table 2 below was added over 5 hours from the start of polymerization.
Similarly, an aqueous initiator solution having the composition shown in Table 2 below was added over a period of 6 hours from the start of the polymerization, and the mixture was held for another 30 minutes.

[Table 2] After the completion of the polymerization reaction, the mixture was cooled to obtain a milky white polymer dispersion. The weight average molecular weight of the THF soluble portion of the polymer is 57,0
The average particle size measured by UPA 00 was 56 nm, and Tg was 84 ° C.

(Colorant Fine Particle Dispersion) Pigment Blue 15: 3 Aqueous Dispersion (EP-700 Blue GA,
Dainichi Seika, solid content 35%) was used. The average particle size measured by UPA was 150 nm.

(Charge control agent fine particle dispersion) 4,4'-methylenebis [2- [N- (4-chlorophenyl) amide] -3-hydroxynaphthalene] 20 parts, alkylnaphthalenesulfonate 4 parts, deionized water 76 Was dispersed in a sand grinder mill to obtain a dispersion of charge control agent fine particles. The average particle size measured by UPA was 200 nm.

[Table 3] Using each component having the composition shown in Table 3 above, a toner was manufactured by the following procedure.

The reactor was charged with the polymer primary particle dispersion and a 15% neogen SC aqueous solution, mixed uniformly, and then added with the colorant fine particle dispersion, and further uniformly mixed. While stirring the resulting mixed dispersion, an aqueous solution of aluminum sulfate was added dropwise (0.6 part as a solid content). Thereafter, the temperature was raised to 50 ° C. over 30 minutes with stirring and maintained for 1 hour,
The temperature was raised to 60 ° C. over a further 15 minutes and held for 30 minutes.
A charge control agent fine particle dispersion, a resin fine particle dispersion, and an aqueous solution of aluminum sulfate (0.07 part as solid content) were added in this order, and the temperature was raised to 62 ° C. over 10 minutes and maintained for 30 minutes. 1
After adding a 5% aqueous solution of Neogen SC (3 parts as a solid content), the temperature was raised to 95 ° C. over 40 minutes and maintained for 4 hours.
Thereafter, the mixture was cooled, filtered, washed with water, and dried to obtain a toner.

To 100 parts of this toner, 0.6 part of hydrophobic surface-treated silica was mixed and stirred to obtain a developing toner TD1. The volume average particle diameter of the developing toner TD1 measured by a Coulter counter is 7.6 μm, the ratio of the volume average particle diameter to the number average particle diameter is 1.12, and the 50% circularity is 0.
95.

[Production of Transfer Belt] The following components were kneaded with a twin-screw kneading extruder to obtain a pellet-shaped resin composition.
Next, extruded in a molten state by an extruder with an annular die,
Cool and solidify, φ130mm × L320mm × 150
μm, a seamless belt having a surface resistivity of 3 × 10 ⁹ Ω / □ (average). The components were as follows.

• Seamless belt SB1 84 parts by weight of polybutylene terephthalate (Novadol 5010 manufactured by Mitsubishi Engineering-Plastic Corporation) 16 parts by weight of carbon black (Denka Black granules manufactured by Denki Kagaku KK)

-Seamless belt SB2 Ethylene tetrafluoroethylene copolymer (Aflon C55A manufactured by Asahi Glass Co., Ltd.) 84 parts by weight Carbon black (Denka Black granules manufactured by Denki Kagaku KK) 16 parts by weight

(Types of Oxide Particles) Oxide particles A: Aerosil 20 manufactured by Nippon Aerosil Co., Ltd.
0 (SiO ₂ particle primary particle diameter average about 12 nm) Oxide particle B: Aerosil R8 manufactured by Nippon Aerosil Co., Ltd.
12 (trimethylsilyl group-introduced surface of SiO ₂ particles, primary particle diameter average about 7 nm) Oxide particles C: Aerosil R2 manufactured by Nippon Aerosil Co., Ltd.
02 (SiO ₂ particles treated with silicone oil, primary particle diameter average about 14 nm)

(Formation of Oxide Particle Layer) The above-mentioned oxide particles were applied using a hexane solvent so that 0.1 g of the oxide particle layer was formed when dried per one seamless belt.

[Evaluation Method] Contact Angle For each of the transfer belts (seamless belts SB1 and SB2) obtained by the above procedure, oxide particles A, B,
The contact angle of the surface was measured with or without C applied. The measurement was performed using a goniometer-type contact angle measuring device, and water (distilled water) was used as a test solution.

Fixing of toner Seamless belt drive roller, charging section, toner supply section,
A unit for evaluating toner fixation comprising a transfer section, a cleaning section, and a charge removing section was prepared. The developing toner TD1 obtained by the above-described procedure and each transfer belt (seamless belt S
B1, SB2) by the following combinations (Examples 1 to 3)
4. In Comparative Examples 1 and 2, each was attached to the toner fixing evaluation unit, and charged, supplied with toner, transferred, cleaned,
The complete set of steps for static elimination was repeated 100,000 times, and the image defects (white spots in solid portions, etc.) due to the toner fixation on the printed matter surface were visually evaluated.

(Results) The evaluation results of the above items in Examples 1 to 4 and Comparative Examples 1 and 2 are shown below.

(Example 1) The seamless belt SB1
The above oxide particles A were applied thereto, and the contact angle with water was measured. As a result, the value was as high as 120 °. Using the developing toner TD1, the set of steps by the toner fixing evaluation unit was repeated 100,000 times to confirm the image. However, no image disturbance due to the fixing was observed, and a good image was maintained.

Example 2 In the same manner as in Example 1, the oxide particles B were applied to the seamless belt SB1.
When the contact angle with water was measured, it showed a high value of 160 °. Using the developing toner TD1, the set of steps by the toner fixing evaluation unit was repeated 100,000 times to confirm the image. However, no image disturbance due to the fixing was observed, and a good image was maintained.

(Example 3) In the same manner as in Example 1, the oxide particles C were applied to the seamless belt SB1.
When the contact angle with water was measured, it showed a high value of 160 °. Using the developing toner TD1, the set of steps by the toner fixing evaluation unit was repeated 100,000 times to confirm the image. However, no image disturbance due to the fixing was observed, and a good image could be maintained.

(Example 4) In the same manner as in Example 1, the above-mentioned oxide particles B were applied to the above-mentioned seamless belt SB2.
When the contact angle with water was measured, it showed a high value of 160 °. Using the developing toner TD1, the set of steps by the toner fixing evaluation unit was repeated 100,000 times to confirm the image. However, no image disturbance due to the fixing was observed, and a good image was maintained.

(Comparative Example 1) The above seamless belt SB1
The contact angle was measured without adhering oxide particles to the sample, and was found to be 69 °. Further, using the developing toner TD1, a set of steps by the toner fixing evaluation unit is set to 10
When the image was confirmed repeatedly 10,000 times, many image disturbances such as white spots caused by toner sticking occurred.

(Comparative Example 2) The above seamless belt SB2
The contact angle was measured without adhering oxide particles to the sample, and was found to be 100 °. When the image was confirmed 100,000 times by the toner fixing evaluation unit, the image was disturbed due to the toner fixing such as white spots.

[0119]

As described above, according to the image forming apparatus and the image forming method of the present invention, the wax content is 5 to 4%.
By using the toner of 0% by weight in combination with the transfer belt having an oxide particle layer on the outermost surface, the adhesion of the toner to the transfer belt is reduced, and the transfer rate of the toner to the medium is increased. It is possible to stably form an image and obtain a high-gradation, high-resolution image excellent in fine line reproducibility and gradation.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a main configuration of an embodiment of an electrophotographic apparatus (image forming apparatus) used in the present invention.

FIG. 2 is a schematic diagram showing a main part configuration of an embodiment of a full-color tandem type electrophotographic apparatus (image forming apparatus) used in the present invention.

[Explanation of symbols]

 Reference Signs List 1 photoconductor 2 charging device (charging roller) 3 exposure device 4 developing device 4k black developing device 4y yellow developing device 4c cyan developing device 4m magenta developing device 5 primary transfer device 6 cleaning device 7 fixing device 8 intermediate transfer belt (transfer belt) 8a, 8b, 8c Conveying roller 9 Secondary transfer device 10 Conveying transfer belt (transfer belt) 41 Developing tank 42 Agitator 43 Supply roller 44 Developing roller 45 Restriction member 71 Upper fixing member (Fixing roller) 72 Lower fixing member (Fixing roller) ) 73 heating device T toner Tk black toner Ty yellow toner Tc cyan toner Tm magenta toner P recording paper (paper, medium)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuo Mitsuhashi 1000, Kamoshita-cho, Aoba-ku, Yokohama-shi, Kanagawa Prefecture Inside the Mitsubishi Research Institute, Inc. F-term in Yokohama Research Laboratory, Chemical Co., Ltd. (reference) MC20

Claims (14)

[Claims] 1. An image forming apparatus comprising at least a toner and a transfer belt, wherein the toner has a wax content of 5 to 40%, and the transfer belt has an oxide particle layer on the outermost surface. An image forming apparatus, comprising: 2. The image forming apparatus according to claim 1, wherein said transfer belt is an intermediate transfer belt. 3. The image forming apparatus according to claim 1, wherein said transfer belt is a transfer belt. 4. The toner having a 50% circularity of 0.9 to 1.
4. The method according to claim 1, wherein the value is 0.
Item 10. The image forming apparatus according to item 1. However, the 50% circularity is equivalent to the cumulative particle size distribution value at 50% of the value obtained from the equation (circularity = perimeter of a circle having the same area as the projected area of the particle / perimeter of the projected image of the particle). And 5. A toner having a volume average particle diameter (D _V ) of 3 to 3.
The image forming apparatus according to claim 1, wherein the thickness of the image forming apparatus is 8 μm. 6. The relationship between the volume average particle diameter (D _V ) and the number average particle diameter (D _N ) of the toner is 1.0 ≦ D _V / D _N ≦ 1.3.
The image forming apparatus according to claim 1, wherein: 7. The measured value (number) of particles having a particle size of 0.6 to 2.12 μm by a flow type particle analyzer of the toner is as follows:
The image forming apparatus according to any one of claims 1 to 6, wherein the number of particles is 15% or less of the total number of particles. 8. An oxide particle used in the oxide particle layer of the transfer belt is made of SiO ₂ , Al ₂ O ₃ , TiO ₂ , S
The image forming apparatus according to claim 1, wherein the image forming apparatus is selected from nO ₂ and ZnO. 9. The image forming apparatus according to claim 1, wherein the oxide particles used in the oxide particle layer of the transfer belt have been subjected to a hydrophobic treatment. . 10. The method of claim 1, wherein the hydrophobizing treatment introduces at least one functional group selected from an alkylsilyl group, a halogenated alkyl group, an alkoxyalkylsilyl group, and an alkyl group onto the surface of the oxide particles. The image forming apparatus according to claim 9, wherein: 11. The image forming apparatus according to claim 1, wherein a contact angle of the surface of the oxide particle layer of the transfer belt with water is 90 ° or more. 12. The photoconductor according to claim 1, further comprising a photosensitive member having a photosensitive layer in which a charge generation layer containing oxytitanium phthalocyanine and a charge transfer layer are laminated. 4. The image forming apparatus according to claim 1. 13. A photoconductor is subjected to digital image exposure, and the electrostatic latent image formed on the photoconductor by the image exposure is developed using a toner having a wax content of 5 to 40%. The toner image on the photoconductor obtained by development is
An image forming method, wherein the image is transferred onto an intermediate transfer belt having an oxide particle layer on the outermost surface. 14. A photoconductor is subjected to digital image exposure, and the electrostatic latent image formed on the photoconductor by the image exposure is developed using a toner having a wax content of 5 to 40%. An image forming method, comprising transferring a toner image on the photoconductor obtained by development to a medium, and conveying the medium by a transfer belt having an oxide particle layer on the outermost surface.