JP2008026675A - Image forming method and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a deterioration in a cleaning blade due to wear or the like by improving the cleaning property of the cleaning blade while maintaining high image quality using a spherical or nearly spherical toner. <P>SOLUTION: An image forming method including a cleaning step of removing toner remaining on a latent image carrier with a cleaning blade is provided. The toner satisfies the relationship of [Y≥-0.05X+0.029] between a space factor X of a toner powder layer after evenly pressurizing and compressing a powder layer of toner particles mainly made up of a resin and a pigment and having an average circularity of ≥0.95, and a torque value Y of a conical rotor generated by thrusting the conical rotor under rotation into the toner powder layer and carrying out rotational transfer of the conical rotor in the powder layer. The cleaning blade contains a dispersed filler having an average particle diameter of 0.1-5.0 μm. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming method and an image forming apparatus of a blade cleaning type using an electrophotographic process such as a copying machine, a printer, and a facsimile.

  In an electrophotographic transfer-type image forming apparatus, a latent image is formed by exposing a document image on a photosensitive member, which is a latent image carrier uniformly charged by a charging device, and then the latent image is developed. A toner is attached by the apparatus to be visualized as a toner image, and the toner image is transferred to a transfer paper or an intermediate transfer medium by a transfer apparatus. The toner remaining on the photoconductor after transfer is removed from the photoconductor by a cleaning device, and the photoconductor is continuously used repeatedly.

Conventionally, a toner used in an electrophotographic system has a conventional dispersion of a colorant such as a dye, pigment, or carbon black in a binder resin made of a natural or synthetic polymer, and the resulting dispersion is about 1 to 30 μm. It is manufactured by pulverizing particles having a particle size. Here, in order to perform satisfactory printing or printing, the electrophotographic toner has various excellent physical properties, such as mechanical properties such as particle size, shape, specific gravity, fluidity, electrical resistance, dielectric constant, etc. It must have thermal properties such as electrical properties, softening point, melting point, optical properties, safety, storage stability, etc. Among the above-mentioned physical properties, the fluidity of toner is one of very important physical properties because it is related to the stability of replenishing toner from the hopper of the developing device, the recoverability of toner from the cleaning device, and the like.
In addition, the image quality of copying machines, printers, and the like has been increasing, and recently, the reproducibility of fine dots has become very important. The dot reproducibility is greatly influenced by fluidity in addition to the charge amount of toner and developer, and it is necessary to stably supply a uniform toner layer or developer layer to a fine latent image portion. It is coming.

Therefore, as an invention related to an electrophotographic toner, Patent Document 1 (Japanese Patent Laid-Open No. 1-203941) measures the time required to drop through a narrow portion of a funnel to which a magnetic field is applied. A method for evaluating the fluidity of a developer in a developing machine and a developer (toner, carrier) having specific fluidity for improving image quality by the evaluation method are disclosed. Patent Document 2 (Japanese Patent Laid-Open No. 4-116449) discloses a method for measuring the angle when a toner is placed on a tiltable plate, the plate is gradually tilted, and the flow starts and ends. The use of specific flow toners to obtain optimal charging properties by the method is disclosed. Furthermore, Patent Document 3 (Japanese Patent Laid-Open No. 2000-292967) discloses a method in which a plurality of sieves are stacked and toner is put on the sieves, and vibrations in the horizontal direction and the vertical direction are applied to the sieve parts after a certain period of time. A method for calculating a numerical value by multiplying the amount of toner remaining in each sieve portion by a preset coefficient and a toner measuring method for confirming long-term storage by the calculation method are disclosed.
However, in these methods, there is a large variation in data, and there are differences depending on the measurer, and it has not been possible to evaluate the fine difference in fluidity between toners.

Furthermore, recently, as the image quality has improved, the toner used in the image forming apparatus has been reduced in size and function. For this reason, the structure of the toner has become complicated, and fine control during production has become necessary. In particular, since toner fluidity affects various image qualities in addition to dot reproducibility, there is a need for a toner based on a highly accurate evaluation method with no individual differences in terms of evaluation.
In addition, when the toner preparation method changes from the pulverization method to another method such as a polymerization method, the change in the flow characteristics with respect to the manufacturing conditions is large, and finer control during production and There is a further need for toners of specific fluidity based on the evaluation and the evaluation method.
In Patent Document 4 (Japanese Patent Laid-Open No. 8-220793), a toner and a flow in which the space ratio of a stable toner layer becomes 0.51 to 0.54 (51.0 to 54.0%) after being pressed for a certain period of time. And a toner having a specific fluidity based on the quantification method. Although this technique captures one aspect of toner fluidity, it may exhibit the same space ratio even when the frictional resistance of the toner surface is different, and is insufficient to evaluate the difference in fluidity. . Moreover, it does not mention about the space rate in the case of not mixing an additive.

On the other hand, as a cleaning device, a cleaning device using a cleaning blade, a cleaning device using a fur brush roller made of conductive or insulating fibers, a cleaning device using a cleaning roller having polishing ability, and a lubricant substance by itself. Various types of devices are known, such as a cleaning device using a cleaning roller included in a cleaning device, a cleaning device using a magnetic brush roller in which magnetic powder is arranged on the roller surface, and a cleaning device using an aspirator. The most widely used method is a method using a cleaning blade. It has a simple structure and high toner removability.
However, in any of the above-described methods, it is difficult to ensure a sufficient cleaning capability for toner or spherical toner having an average particle size distribution of 7 μm or less, which is employed for high image quality.

As a production method for reducing the toner particle size, a polymerization method is effective instead of a conventional pulverization method from the viewpoint of production cost. The small particle size toner produced by the polymerization method has a shape close to a sphere and a sharp particle size distribution, so that good image quality with excellent reproducibility of fine lines and dot reproducibility of digital images can be obtained. There is.
When polymerized toner with a small particle size is used, it is difficult to clean because the shape is close to a true sphere and the particle size is small compared to the toner produced by the conventional pulverization method, and the cleaning member slips through. There is a drawback that cleaning defects such as black spots occur. In particular, when a cleaning blade is used, defective cleaning tends to occur when the edge of the blade is worn or chipped by repeated use. In addition, due to the use, the photoreceptor is worn and fine irregularities are formed, and cleaning defects are likely to occur even when the surface roughness increases.
In order to prevent wear and chipping of the cleaning blade, it is widely used to apply or supply a lubricant to the blade surface.

  In Patent Document 5 (Japanese Patent Laid-Open No. 2002-72713), a certain amount of toner is consciously supplied to a cleaning blade, and the toner is used as a lubricant. However, a toner that often slips through may function as a blade abrasive rather than as a lubricant, and rather promotes wear of the cleaning blade. Patent Document 6 (Japanese Patent Laid-Open No. 9-50221) attempts to improve environmental stability by defining blade properties. However, in the case of a spherical toner having a small particle diameter, it is not always sufficient. Durability cannot be obtained.

  Further, in Patent Document 7 (Japanese Patent Laid-Open No. 2003-98925), a combination of a cleaning blade having a rebound resilience at 30 ° C. of 5 to 30% and a rebound resilience at 40 ° C. of 10 to 40% and a substantially spherical toner. Has been proposed. It is a proposal aimed at preventing blade deterioration by defining rebound resilience at a relatively high temperature of 30 to 40 ° C. However, the cleaning blade does not always provide sufficient cleaning properties. In particular, when a spherical toner is used, a phenomenon in which the residual toner slips through the cleaning blade is likely to occur, and the residual toner is often brought into the next image forming process and adversely affects the image quality. In addition, we are trying to ensure cleaning performance using a photoconductor containing a siloxane resin and a cleaning blade with specific physical properties. Invite.

Further, in Patent Document 8 (Japanese Patent Laid-Open No. 2000-122347), a method of using an additive having a specific shape as a cleaning aid is disclosed. In Patent Document 9 (Japanese Patent Laid-Open No. 8-62893), a pulverized toner is mixed. Thus, a method of using as a cleaning aid has been proposed. These have a tendency to accumulate and shortage of cleaning aids during continuous use and lack stability.
In general, in order to improve the cleaning of the spherical toner, the contact pressure of the cleaning blade to the photosensitive member may be increased. However, the surface of the photoreceptor is easily worn by the high pressure of the blade, and high durability is difficult.

Further, Patent Document 10 (Japanese Patent Laid-Open No. 59-200284) proposes a method of adding fine particles to the surface of the cleaning blade. However, when adhering to the surface of the cleaning blade, dropout of particles is inevitable and the effect does not last long.
Patent Document 11 (JP-A-5-158389) proposes to increase the strength of the blade and improve the durability by mixing an inorganic filler such as crystalline silica or titanate into the blade. There is no mention of cleanability.
Further, in Patent Document 12 (Japanese Patent Laid-Open No. 2005-195681) and Patent Document 13 (Japanese Patent Laid-Open No. 2003-280474), fine particles having lubricity and abrasiveness are added to the inside and protruded from the blade surface. Although it has been proposed, it is not a new proposal because even if fine particles are simply added, the particles naturally protrude from the surface of the cleaning blade.
Further, Patent Document 14 (Japanese Patent Laid-Open No. 2002-149031) proposes that the surface layer of the cleaning blade contains a fluororesin and the surface roughness is combined with a specific photoconductor. Is low in affinity, easily falls off the blade surface, and the effect is difficult to sustain. Also, the rubber elasticity of the entire blade tends to become unstable. Since the surface roughness of the photoreceptor varies with time of use, the cleaning characteristics tend to become unstable.
In addition, when the blade edge is worn or chipped due to repeated use, cleaning failure tends to occur.
Further, the technique described in Patent Document 15 (Japanese Patent Application Laid-Open No. 2003-208035) has a drawback that the contact pressure is very high and thus the wear of the photosensitive member and the cleaning blade easily proceeds. Also, toner is rolled between the photoreceptor and the blade, and toner components adhere to the photoreceptor, so that so-called filming is likely to occur.
Further, in Patent Document 16 (Japanese Patent Application Laid-Open No. 2004-279991), it is proposed that the acrylic modified polyorganosiloxane is dispersed in the blade to prevent the blade from being worn or chipped. By using a material having high affinity with urethane, the frictional force between the photoreceptor and the blade is reduced, and the durability and stability of the blade are improved. However, simply combining these materials is not sufficient to clean small diameter and spherical toner at the same time.

JP-A-1-203941 JP-A-4-116449 JP 2000-292967 A Japanese Patent Application Laid-Open No. 08-220793 JP 2002-72713 A Japanese Patent Laid-Open No. 9-50221 JP 2003-98925 A JP 2000-122347 A JP-A-8-62893 JP 59-200284 A JP-A-5-158389 JP 2005-195681 A JP 2003-280474 A JP 2002-149031 A JP 2003-208055 A JP 2004-279951 A

In view of the above problems, the present invention uses a spherical or near-spherical toner to improve cleaning properties while maintaining high image quality, and to prevent deterioration of the cleaning blade due to wear or the like. It is an object to provide an apparatus.
Another object of the present invention is to maintain the cleaning performance even when the cleaning blade is worn to some extent.

The above problems are solved by the present inventions (1) to (18) below.
(1) “Charging step of charging the latent image carrier by bringing a charging member into contact with or close to the surface of the latent image carrier carrying the latent image, and a latent image forming step of forming a latent image on the latent image carrier A transfer electric field is formed between the developing step of developing the latent image on the latent image carrier with toner attached thereto, and the surface moving member that moves while contacting the latent image carrier, A transfer step of transferring the toner image formed on the latent image carrier onto a recording material or a surface movement member sandwiched between the surface movement member and the toner remaining on the latent image carrier with a cleaning blade And a cleaning step for cleaning, wherein the toner is a toner obtained by uniformly pressing and compressing a powder phase of toner particles having an average circularity of 0.95 or more and comprising at least a resin and a pigment. Powder layer space ratio X and toner powder layer The torque value Y of the conical rotor generated by rotating the conical rotor while rotating the conical rotor and rotating the conical rotor in the powder layer has a relationship of [Y ≧ −0.05X + 0.029]. An image forming method, wherein the cleaning blade is dispersed with a filler having an average particle size of 0.1 to 5.0 μm ”
(2) “Image forming method according to item (1), wherein the filler of the cleaning blade is made of titanium oxide or calcium carbonate”
(3) “The image forming method according to (1) or (2) above, wherein the filler of the cleaning blade is needle-shaped”
(4) “The image forming method according to (3), wherein the cleaning blade further includes a spherical filler as the filler”
(5) “Image forming method according to item (1), wherein the filler of the cleaning blade is an acrylic-modified polyorganosiloxane”
(6) “Items (1) to (5), including a step of supplying organic or inorganic fine particles having an average particle size of 80 nm to 2.0 μm to the surface of the latent image carrier”. The image forming method according to any one of
(7) “The image forming method according to (6) above, wherein the toner is added with organic or inorganic fine particles having an average particle diameter of 80 nm to 2.0 μm”
(8) The above-mentioned items (1) to (7), characterized by comprising a lubricant supplying step of supplying a lubricant to the surface of the latent image carrier to make the coefficient of friction of the surface of the photosensitive member 0.2 or less. The image forming method according to any one of the items "
(9) The image forming method according to any one of items (1) to (8), wherein the latent image carrier has an acrylic modified polyorganosiloxane dispersed on a surface thereof. "
(10) “Latent image carrier that carries a latent image, a charging device that charges the latent image carrier by bringing a charging member into contact with or close to the surface of the latent image carrier, and forms a latent image on the latent image carrier. A transfer electric field is formed between the latent image forming device, the developing device that attaches toner to the latent image of the latent image carrier and develops, and the surface moving member that moves while contacting the latent image carrier. A transfer device for transferring the toner image formed on the latent image carrier onto the recording material sandwiched between the surface moving member or the surface moving member, and cleaning the toner remaining on the latent image carrier. An image forming apparatus comprising a cleaning device for cleaning with a blade, wherein the toner is made of at least a powder phase of toner particles having an average circularity of 0.95 or more made of at least a resin and a pigment, after being uniformly pressed and compressed Toner powder layer space ratio X and toner The torque value Y of the conical rotor generated by rotating the conical rotor into the powder layer while rotating and moving the conical rotor in the powder layer is [Y ≧ −0.05X + 0.029]. The image forming apparatus is characterized in that the cleaning blade disperses a filler having an average particle diameter of 0.1 to 5.0 μm ”
(11) “Image forming apparatus according to item (10), wherein the filler of the cleaning blade is made of titanium oxide or calcium carbonate”
(12) “Image forming method according to item (10) or (11), wherein the filler of the cleaning blade is needle-shaped”
(13) “The image forming method according to item (12), wherein the cleaning blade further includes a spherical filler as the filler”.
(14) “The image forming apparatus according to (10), wherein the filler of the cleaning blade is an acrylic-modified polyorganosiloxane”
(15) In the above (10) to (14), organic or inorganic fine particles having an average particle size of 80 nm to 2.0 μm are supplied to the surface of the latent image carrier. Any of the image forming apparatuses "
(16) "The image forming apparatus according to item (15), wherein the toner is an organic or inorganic fine particle having an average particle size of 80 nm to 2.0 µm added"
(17) The above (10) to (16), characterized in that it has a lubricant supply means for supplying a lubricant to the surface of the latent image carrier to make the coefficient of friction of the surface of the photosensitive member 0.2 or less. The image forming apparatus according to any one of Items
(18) The image forming apparatus according to any one of (10) to (17), wherein the latent image bearing member has an acrylic modified polyorganosiloxane dispersed on a surface thereof. "

  According to the present invention, it is possible to provide a blade cleaning type image forming apparatus capable of improving the cleaning property while maintaining high image quality using a spherical or nearly spherical toner and preventing the cleaning blade from being deteriorated due to wear or the like. Further, it becomes possible to maintain the cleaning property even when the cleaning blade is worn to some extent.

[toner]
The present invention uses a combination of a specific fluidity toner and a specific cleaning blade. The fluidity value of the toner is caused to enter the toner powder phase while rotating the conical rotor. This is a measurement result of torque or load generated when moving in the body phase.
FIG. 1 is a schematic configuration diagram of a conical rotor type toner fluidity evaluation apparatus used in the practice of the present invention.
The shape of the conical rotor can be arbitrarily designed, but a conical rotor having an apex angle of 20 to 150 ° is suitable. If the apex angle of the cone is smaller than 20 °, the resistance to the toner powder phase is small, so the torque and load are small, and a fine difference in fluidity cannot be evaluated. On the other hand, when the apex angle is larger than 150 °, the force in the direction of pressing the toner powder phase becomes large and the toner particles are easily deformed, which is not suitable for the evaluation of the toner fluidity.
The length of the conical rotor needs to be long enough so that the conical rotor surface is continuously present in the toner powder phase.

  Moreover, it is better that the conical rotor surface has grooves. Rather than measuring the friction component between the material surface of the conical rotor and the toner particles, it is better to measure the friction component between the toner particles and the toner particles. For this purpose, when the conical rotor rotates and enters the toner powder phase, the toner particles enter the grooves cut on the surface of the conical rotor, and the toner particles and the surrounding toner enter. It is more appropriate to measure the state of friction with the particles. The shape of the groove is not limited, but it is necessary to devise so that the contact between the material surface of the conical rotor and the toner particles becomes small.

The conical rotor shown in FIG. 1 is obtained by cutting a groove straight from the apex of the cone in the direction of the bottom, and has a sawtooth shape in which the cross section of the groove is formed of triangular irregularities. The pitch of the triangular grooves is preferably a length that divides the circumference into 30 to 60 equal parts. In this case, the contact between the conical rotor material surface and the toner particles is only at the tip of the crest of the triangular groove. Most of the contact is between the toner particles entering the groove and the surrounding toner particles.
The material of the conical rotor can be arbitrarily selected, but a material that is easy to process, has a hard surface, and does not change quality is preferable. A material that is not charged is suitable. Examples of this are SUS, Al, Cu, Au, Ag, brass, and the like.
From such a viewpoint, the toner used in the image forming method and apparatus of the present invention has an attribute measured under the following conditions in the present invention.
The conical rotor type toner fluidity evaluation device;
The apex angle of the cone; 30 degrees,
Length of conical rotor (height from top to bottom of cone); 20 mm,
Conical rotor shape; as shown in FIG.
Triangular groove pitch; Divide the circumference into 40 equal parts,
Conical rotor material: Cu.
Here, in the conical rotor shown in FIG. 1, the pitch of the triangular grooves provided therein divides the circumference into 40 equal parts.

The torque and load of the toner powder vary depending on the rotational speed of the conical rotor, that is, the rotational speed per minute (hereinafter, abbreviated as the rotational speed; the unit is rpm) and the conical rotor intrusion speed. In this measurement, in order to increase the accuracy of the measurement, the rotation speed and the penetration speed of the conical rotor are reduced so that the delicate contact state between the toner particles can be measured. Therefore, the measurement conditions were as follows.
・ Rotation speed of conical rotor: 0.1 to 100 rpm
・ Penetration speed of conical rotor: 0.5 to 150 mm / min
When the rotational speed of the conical rotor is smaller than 0.1 rpm, it is easily affected by the delicate state of the toner powder phase, which causes a problem of torque measurement variation and is not suitable for measurement. If it is higher than 100 rpm, the toner scatters and cannot be measured stably.
When the penetration speed of the conical rotor is slower than 0.5 mm / min, it is easily affected by the delicate state of the toner powder phase, and a measurement variation problem occurs, which is not suitable for measurement. When it is faster than 150 mm / min, the toner powder phase tends to be in a compacted state, and the influence of toner deformation or the like appears, which is not suitable for fluidity evaluation.

For measurement, a certain amount of toner is put into a container and set in the apparatus. Thereafter, the conical rotor is rotated to enter the toner powder phase contained in the container. Before the actual measurement is started, an operation of raising and lowering the conical rotor to bring the toner powder phase into a uniform state may be performed.
The toner powder phase may be pressurized to create a compacted state, and the conical rotor may be lowered into the compacted toner phase for measurement.
In the present invention, the measurement is performed under the following conditions.
・ Rotation speed of conical rotor: 1.0 rpm
・ Penetration speed of conical rotor: 1.0 mm / min
・ Pressurization of toner layer: pressurization for 60 seconds or more at 0.1 kg / cm ² or more
-Triangular groove pitch on the conical rotor surface: 40 parts of the bottom of the conical section-Triangular groove shape: equilateral triangle If the rotational torque is 1.5 × 10 ⁻³ Nm or more when the conical rotor enters 20 mm, it is good Shows cleanability. Preferably it is 2.0 × 10 ⁻³ Nm or more.
The reason for this is not clear, but in the operating state of the cleaning blade, toner stays in the vicinity of the contact portion between the blade and the photoconductor, forming a stationary layer, but it is newly carried on the photoconductor. It is considered that the toner is easily peeled off from the photoreceptor if the frictional force between the toners is strong when the toner comes into contact with the stationary layer.

Next, the space ratio will be described. The left side of FIG. 1 shows a state in which the toner powder filled in the measuring device is compressed with a constant load. In the present invention, the load during compression is 1.6 kg. When the space ratio is ε, the mass of the toner powder filled in the measuring device is M, the true specific gravity of the toner powder is ρ, and the volume of the toner layer is V, the space ratio ε is
ε = (V−M / ρ) / V
It is represented by A higher space ratio ε is better. The relationship between the space ratio and the cleaning property is not clear, but it is considered that the lower the space ratio, the higher the density of toner accumulated at the tip of the cleaning blade, and the easier it is to slip through the cleaning blade.

Further, since the toner having a smaller volume average particle diameter Dv can improve the reproducibility of fine lines, a toner having a maximum particle size of 8 μm or less is used. However, since the developing property and the cleaning property are lowered when the particle size is small, at least 3 μm is preferable. Further, if the particle size is less than 3 μm, the toner having a small particle diameter that is difficult to be developed on the surface of the carrier or the developing roller increases. This is not preferable because an abnormal image such as fogging is formed.
Moreover, it is preferable that the particle size distribution represented by ratio (Dv / Dn) of the volume average particle diameter Dv and the number average particle diameter Dn is in the range of 1.05-1.40. By sharpening the particle size distribution, the toner charge amount distribution can be made uniform. When Dv / Dn exceeds 1.40, the toner charge amount distribution is wide and the amount of reversely charged toner increases, making it difficult to obtain a high-quality image. If Dv / Dn is less than 1.05, it is difficult to produce and it is not practical. The particle size of the toner is 50,000 by using a Coulter Counter Multisizer (manufactured by Coulter Co., Ltd.) and selecting an aperture having a measurement hole size of 50 μm corresponding to the particle size of the toner to be measured. It is obtained by measuring the average particle size of the particles.

The toner preferably has a shape factor SF-1 in the range of 100 to 180 and a shape factor SF-2 in the range of 100 to 180 of the average circularity. 2A and 2B are diagrams schematically showing the shape of the toner particles. FIG. 2A is a diagram for explaining the shape factor SF-1, and FIG. 2B is a diagram for explaining the shape factor SF-2. The shape factor SF-1 indicates the ratio of the roundness of the toner shape and is represented by the following formula (1). This is a value obtained by dividing the square of the maximum length MXLNG of the shape formed by projecting the toner on a two-dimensional plane by the figure area AREA and multiplying by 100π / 4.
SF-1 = {(MXLNG) ² / AREA} × (100π / 4) (1)
When the value of SF-1 is 100, the shape of the toner particles is a true sphere, and becomes irregular as the value of SF-1 increases.
When the circularity of the toner is 0.95 or more, the toner particles are easily packed very densely. Further, it has been found that the above-mentioned parameters in the present invention cannot be obtained because the fluidity is very good because there are no irregularities on the surface.

The shape factor SF-2 indicates the ratio of the unevenness of the shape of the toner particles, and is represented by the following formula (2). A value obtained by dividing the square of the perimeter PERI of the figure formed by projecting the toner on the two-dimensional plane by the figure area AREA and multiplying by 100π / 4.
SF-2 = {(PERI) 2 / AREA} × (100π / 4) (2)
When the value of SF-2 is 100, unevenness does not exist on the toner surface, and as the value of SF-2 increases, the unevenness of the toner particle surface becomes more prominent.
Specifically, the shape factor is measured by taking a photograph of the toner with a scanning electron microscope (S-800: manufactured by Hitachi, Ltd.), introducing it into an image analyzer (LUSEX 3: manufactured by Nireco) and analyzing it. Calculated.

When the shape of the toner particles is close to a spherical shape, the contact between the adjacent toner particles becomes a point contact, so that the attractive force between the toners becomes weak, resulting in high fluidity. The adhering force of the toner becomes weak, the transfer rate increases, and the residual toner on the photoreceptor becomes easy to clean.
The shape factors SF-1 and SF-2 of the toner are preferably 100 or more. Further, when SF-1 and SF-2 are increased, the shape becomes indeterminate, the toner charge amount distribution becomes wide, development is not faithful to the latent image, and transfer is not faithful to the transfer electric field. Image quality deteriorates. Furthermore, the transfer rate is reduced, the amount of toner remaining after transfer is increased, and a large cleaning device is required, which is disadvantageous in designing the image forming apparatus. For this reason, SF-1 preferably does not exceed 180, and SF-2 preferably does not exceed 180.

  The shape of the toner can be controlled by the manufacturing method. For example, the toner by the dry pulverization method has an irregular shape in which the toner particle surface is uneven and the toner particle shape is not constant. Even this dry pulverized toner can be made into a nearly spherical toner by applying mechanical or thermal treatment. In many cases, a toner produced by forming droplets by a suspension polymerization method or an emulsion polymerization method has a smooth surface and a nearly spherical shape. Moreover, it can be made into an ellipse by stirring in the middle of the reaction in a solvent and applying a shearing force.

  Further, as the toner having such a substantially spherical shape, a toner material solution in which a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent are dissolved or dispersed in an organic solvent, respectively. A toner that undergoes crosslinking and / or elongation reaction in an aqueous medium is preferred.

Hereinafter, the constituent material of the toner and a suitable manufacturing method will be described.
As resins, polystyrene resin, epoxy resin, polyester resin, polyamide resin, styrene acrylic resin, styrene methacrylate resin, polyurethane resin, vinyl resin, polyolefin resin, styrene butadiene resin, phenol resin, polyethylene resin, silicon resin, butyral resin, terpene There are resins, polyol resins and the like.
Examples of vinyl resins include styrene such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene, and homopolymers thereof: styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer. Polymer, styrene-vinyl naphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methacrylic copolymer Acid methyl copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer Coalescence, styrene-vinyl ethyl acetate Copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester Styrene copolymers such as copolymers: polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate and the like.
In particular, the polyester resin has a wide adjustment range of viscoelasticity at 100 to 200 ° C., and it is easy to control the special fixing of the toner.

The polyester resin is composed of a dihydric alcohol as shown in the following group A and a dibasic acid salt as shown in the group B, and further a trihydric or higher alcohol as shown in the group C or Carboxylic acid may be added as a third component.
Group A: ethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4 butanediol, neopentyl glycol, 1,4 butenediol, 1,4-bis (hydroxymethyl) cyclohexane Bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, polyoxypropylene (2,2) -2,2′-bis (4-hydroxyphenyl) propane, polyoxypropylene (3,3) -2, 2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2,0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2,0) -2,2′-bis (4 -Hydroxyphenyl) propane and the like.
Group B: maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, malonic acid, linolenic acid, or These acid anhydrides or esters of lower alcohols.
Group C: Trivalent or higher alcohols such as glycerin, trimethylolpropane and pentaerythritol, and trivalent or higher carboxylic acids such as trimellitic acid and pyromellitic acid.
As the polyol resin, an alkylene oxide adduct of an epoxy resin and a dihydric phenol, or a compound having one active hydrogen in the molecule that reacts with the glycidyl ether and the epoxy group, and an active hydrogen that reacts with the epoxy resin in the molecule. There are those obtained by reacting two or more compounds.

The following are used as the pigment used in the present invention.
Examples of black pigments include azine dyes such as carbon black, oil furnace black, channel black, lamp black, acetylene black, and aniline black, metal salt azo dyes, metal oxides, and composite metal oxides.
Examples of yellow pigments include cadmium yellow, mineral fast yellow, nickel titanium yellow, navel yellow, naphthol yellow S, Hansa yellow G, Hansa yellow 10G, benzidine yellow GR, quinoline yellow lake, permanent yellow NCG, and tartrazine lake. .
Examples of the orange pigment include molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan orange, indanthrene brilliant orange RK, benzidine orange G, and indanthrene brilliant orange GK.
Examples of red pigments include Bengala, Cadmium Red, Permanent Red 4R, Resol Red, Pyrazolone Red, Watching Red Calcium Salt, Lake Red D, Brilliant Carmine 6B, Eosin Lake, Rhodamine Lake B, Alizarin Lake, Brilliant Carmine 3B.
Examples of purple pigments include fast violet B and methyl violet lake.
Examples of blue pigments include cobalt blue, alkali blue, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partially chlorinated, first sky blue, and indanthrene blue BC.
Examples of green pigments include chrome green, chromium oxide, pigment green B, and malachite green lake.
These can use 1 type (s) or 2 or more types.
Especially for color toners, uniform dispersion of good pigments is essential. Instead of putting pigments directly into a large amount of resin, a master batch in which pigments are once dispersed at a high concentration is prepared and diluted. The method of throwing in is used.

A charge control agent is blended (internally added) inside the toner particles. However, it may be used by mixing (external addition) with toner particles. The charge control agent enables optimal charge amount control according to the development system. In particular, in the present invention, the balance between the particle size distribution and the charge amount can be further stabilized.
For controlling the toner to be positively charged, nigrosine and quaternary ammonium salts, triphenylmethane dyes, imidazole metal complexes and salts can be used alone or in combination of two or more. Further, salicylic acid metal complexes, salts, organic boron salts, calixarene compounds, and the like are used for controlling the toner to be negatively charged.
A release agent can be internally added to prevent offset during fixing. Release agents include natural waxes such as candelilla wax, carnauba wax, rice wax, montan wax and derivatives thereof, paraffin wax and derivatives thereof, polyolefin wax and derivatives thereof, sazol wax, low molecular weight polyethylene, and low molecular weight polypropylene. And alkyl phosphate esters. The melting point of these release agents is preferably 65 to 90 ° C. When the temperature is lower than this range, blocking during storage of the toner is likely to occur, and when the temperature is higher than this range, an offset is likely to occur in a region where the fixing roller temperature is low.

  Additives may be added for the purpose of improving the dispersibility of a release agent or the like. As additives, styrene acrylic resin, polyethylene resin, polystyrene resin, epoxy resin, polyester resin, polyamide resin, styrene methacrylate resin, polyurethane resin, vinyl resin, polyolefin resin, styrene butadiene resin, phenol resin, butyral resin, terpene resin, There is a polyol resin or the like, and a mixture of two or more of these resins may be used.

Examples of the method for producing the toner according to the present invention include a pulverization method and a polymerization method (suspension polymerization, emulsion polymerization dispersion polymerization, emulsion aggregation, emulsion association, etc.), but are not limited to these production methods.
The toner of the present invention may be modified by embedding child particles (fine particles) on the surface of the base particles. Fine irregularities can be formed on the toner surface by mixing organic resin particles, inorganic fine particles or the like that are 1/10 or less of the base particles, and fixing them to the base surface by heat treatment or the like.

As the external additive, in addition to these inorganic fine particles, general hydrophobic treated inorganic fine particles can be used together, but the average particle diameter of the hydrophobized primary particles is 1 to 300 nm, more preferably 5 nm to 70 nm. It is desirable to contain inorganic fine particles. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g.
Any known one can be used as long as the conditions are satisfied. For example, silica fine particles, hydrophobic silica, fatty acid metal salts (such as zinc stearate and aluminum stearate), metal oxides (such as titania, alumina, tin oxide, and antimony oxide), fluoropolymers, and the like may be contained.
Particularly suitable additives include hydrophobized silica, titania, titanium oxide, and alumina fine particles. Examples of silica fine particles include HDK H 2000, HDK H 2000/4, HDK H 2050EP, HVK21, HDK H 1303 (above Clariant Japan) and R972, R974, RX200, RY200, R202, R805, R812 (above Japan Aerosil). . Further, as titania fine particles, P-25 (Nippon Aerosil), STT-30, STT-65C-S (above Titanium Industry), TAF-140 (Fuji Titanium Industry), MT-150W, MT-500B, MT-600B MT-150A (taker above). Particularly, the hydrophobized titanium oxide fine particles include T-805 (Nippon Aerosil), STT-30A, STT-65S-S (above Titanium Industry), TAF-500T, TAF-1500T (above Fuji Titanium Industry), MT -100S, MT-100T (above Taka), IT-S (Ishihara Sangyo), etc.

At the same time, organic or inorganic fine particles of 80 nm to 2.0 μm may be added. For example, good results can be obtained by adding spherical silica (for example, spherical silica having an average particle diameter of 120 nm) different from HDK-H2000 as a result.
In the present invention, the toner may be supplied onto the photosensitive member separately from the toner, but if added to the toner, the toner can be supplied at a constant ratio with respect to the toner consumption. Further, the supply and control device is not necessary.
These organic or inorganic fine particles may be selected from the materials exemplified for the toner base and the external additive.

[Cleaning blade]
Next, the cleaning blade will be described.
The material for forming the cleaning blade that scrapes off the toner adhering to the photoreceptor is not particularly limited as long as it is urethane rubber. Among these, when considering the molding process of the cleaning blade, a liquid thermosetting material is used. As the production method, a prepolymer method, a one-shot method, and a pseudo one-shot method which is an intermediate between them are used.
As the liquid forming material, for example, a material mainly composed of a urethane rubber prepolymer and a curing agent is used. The prepolymer for urethane rubber is obtained by partially polymerizing polyisocyanate and polyol.
Examples of the polyisocyanate include 4,4′-diphenylmethane diisocyanate (MDI), isophorone diisocyanate (IPDI), 4,4′-dicyclohexylmethane diisocyanate (water-added MDI), trimethylhexamethylene diisocyanate (TMHDI), and tolylene diisocyanate. (TDI), carbodiimide-modified MDI, polymethylene phenyl polyisocyanate (PAPI), orthotoluidine diisocyanate (TODI), naphthylene diisocyanate (NDI), xylene diisocyanate (XDI), hexamethylene diisocyanate (HMDI), paraphenylene diisocyanate (PDI) Lysine diisocyanate methyl ester (LDI), dimethylyl diisocyanate (DDI), and the like. That. Among these, it is preferable to use MDI, TODI or the like.
Polyols used together with the above polyisocyanates include polyethylene polyols such as polyethylene adipate, polybutylene adipate, polyhexylene adipate, copolymers of ethylene adipate and butylene adipate, polycaprolactone, polyoxytetramethylene glycol, poly Examples include polyether polyols such as oxypropylene glycol. Of these, those having a molecular weight of 1500 to 3000 are preferably used. That is, if it is less than 1500, the physical properties of the resulting urethane rubber tend to decrease, and if it exceeds 3000, the viscosity of the prepolymer tends to increase, and the workability of cleaning blade molding tends to deteriorate. It is.
The urethane rubber prepolymer is prepared as follows using the polyisocyanate and polyol, for example. First, the polyisocyanate and the polyol are blended and mixed. The mixture is then reacted at a temperature of 80 to 120 ° C. for 30 to 90 minutes. Thereby, a prepolymer is obtained.

As the curing agent for the prepolymer for urethane rubber, it is preferable to use a low molecular weight polyol having a molecular weight of 300 or less. Examples of such polyols include ethylene glycol (EG), diethylene glycol (DEG), propylene glycol (PG), dipropylene glycol (DPG), 1,4-butanediol (14BD), hexanediol (HD), 1 , 4-cyclohexanediol, 1,4-cyclohexanedimethanol, xylene glycol (terephthalyl alcohol), triethylene glycol, trimethylolpropane, glycerin, pentaerythritol, and sorbitol.
And from the viewpoint of the ease of mixing operation and the characteristics of the cleaning blade to be the base of the resulting cleaning blade, a suitable combination of the prepolymer and the curing agent is a prepolymer comprising MDI and polyester polyol as the prepolymer. Examples of the curing agent include a combination of 1,4-butanediol, trimethylolpropane, and polyester polyol. The optimum combination is a prepolymer comprising MDI and polyethylene adipate as a prepolymer, and a combination of 1,4-butanediol and trimethylolpropane as a curing agent.

In the present invention, a filler having an average particle size of 0.1 to 5.0 μm is dispersed in the cleaning blade. The average particle diameter of the filler is more preferably 0.2 to 2.0 μm. The amount of the filler is preferably 1.0 to 20% by weight, and more preferably 3.0 to 8.0% by weight.
If the amount is too small, the added effect is not obtained. If the amount is too large, the strength of the cleaning blade may be reduced, or the blade surface may be inferior and adhesion to the photoreceptor may be reduced.

  Examples of the filler include silica fine particles, titanium oxide fine particles, potassium titanate fine particles, calcium carbonate, fatty acid metal salts (such as zinc stearate and aluminum stearate), metal oxides (titania, alumina, tin oxide, antimony oxide, and the like). ) And fluoropolymers.

According to the study by the present inventors, the shape of the filler is preferably a needle shape. The ratio of the acicular major axis to minor axis is preferably 5 to 1 or more, more preferably 20 to 1 or more. Regarding the average particle diameter of such a needle-like filler, the length of the major axis is defined as the particle diameter in the present invention.
By adopting such a shape, the strength of the cleaning blade is increased, and wear of the cleaning blade is suppressed even when a large number of image forming operations are performed. Further, when the fine acicular particles protrude slightly from the blade surface, the scraping effect of the paper powder or the toner composition to be fixed increases. Instead of intentionally protruding, the blade can be naturally protruded as a result of cutting into a required shape. Although it is a specific size of “slight”, it is several nanometers to several tens of nanometers from the observation result.
As such a needle-like filler, titanium oxide or calcium carbonate-based material is particularly preferable. The reason why these are particularly preferable is not clear, but it is considered that the surface is close to hydrophilicity and therefore has good affinity with urethane, which is the main component of the cleaning blade.

  When acrylic-modified polyorganosiloxane is used as the filler, blade turning, squealing, chattering, and the like can be suppressed by reducing the adhesive force with a photoreceptor as a typical example of a latent image carrier. Conventionally, when selecting a cleaning blade, there is a tendency for chatter to occur in a low temperature environment due to the environmental dependence of rubber, and it is easy to generate squeal at a high temperature, so the choice of materials used for the cleaning blade is limited However, the use of acrylic-modified polyorganosiloxane makes it easier to expand the options.

  In addition, adhesion of the toner composition to the surface of the photoreceptor can be reduced. This is presumably due to the fact that the cleaning blade is less likely to be pulled into the photoconductor by reducing the adhesion force, and the pressure applied to the toner sandwiched between the photoconductor and the cleaning blade is reduced.

  In the present invention, the above effect can be further stabilized by setting the coefficient of friction on the surface of the photoreceptor to 0.2 or less. In particular, environmental stability is improved. In addition, after forming a large number of images, wear of the cleaning blade is inevitable, and wear and scratches on the surface of the photoconductor are unavoidable. Even when a change occurs, good image formation can be maintained.

The coefficient of friction of the photoreceptor surface was measured by the method described in JP-A-2001-201899 [0047]. That is, a belt-shaped measuring member obtained by cutting medium-thick high-quality paper so that the paper scribing direction is the longitudinal direction is brought into contact with a quarter of the outer periphery of the surface of the cylindrical photosensitive member, and a load (100 g) is applied to one (lower end). After connecting the force gauge to the other side, the force gauge was moved at a constant speed, and the value of the force gauge when the belt started moving was read and calculated by the following formula.
μs = 2 / π × ln (F / W)
(Where μs: coefficient of static friction, F: force gauge reading (g), W: load (100 g))

In order to reduce the coefficient of friction on the surface of the photoreceptor, there is a method of supplying a lubricant such as fatty acid ester or metal soap to the surface of the photoreceptor. Further, a low friction material such as fluorine-containing fine particles may be added to the photoreceptor surface.
The addition amount of the low friction material is preferably 0.5 to 25% by weight of the surface of the photoreceptor. More preferably, it is 3 to 10% by weight. The amount of addition is determined by a balance with various characteristics such as electric resistance and smoothness on the surface of the photoreceptor.
In the present invention, it is particularly preferable to add acrylic-modified polyorganosiloxane.
This material is easy to spread on the surface of the photoreceptor, and the acrylic part in the molecule has a good affinity with polycarbonate and acrylic resin used as a binder for the photoreceptor, so that the surface can be covered uniformly.
Also, when the same acrylic-modified polyorganosiloxane is used in the cleaning blade, the same material has good affinity, prevents the blade from being pulled in, and maintains high adhesion. Aging and environmental stability can be maintained.
The material for the surface of the photoreceptor is not particularly limited, but polycarbonate, acrylic resin, and polyarylate resin are preferably used.

(Image forming device)
The image forming apparatus of the present invention comprises at least an electrostatic latent image carrier, an electrostatic latent image forming unit, a developing unit, a transfer unit, a fixing unit, and a cleaning unit using a cleaning blade. Furthermore, other means appropriately selected as necessary, for example, a static elimination means, a developer recycling means, a control means and the like are provided.
The image forming method of the present invention is performed using such an image forming apparatus. 4 to 6 show schematic views of examples of the image forming apparatus of the present invention.

The electrostatic latent image forming step is a step of forming an electrostatic latent image on the electrostatic latent image carrier.
There are no particular restrictions on the material, shape, structure, size, etc. of the electrostatic latent image carrier (sometimes referred to as “photoconductive insulator” or “photoconductor”), and among the known ones The shape is preferably a drum shape, and examples of the material include inorganic photoconductors such as amorphous silicon and selenium, and organic photoconductors such as polysilane and phthalopolymethine. It is done. Among these, amorphous silicon or the like is preferable in terms of long life.

  The formation of the electrostatic latent image can be performed, for example, by uniformly charging the surface of the electrostatic latent image carrier and then performing imagewise exposure, and is performed by the electrostatic latent image forming unit. be able to. The electrostatic latent image forming means includes, for example, at least a charger that uniformly charges the surface of the electrostatic latent image carrier and an exposure device that exposes the surface of the electrostatic latent image carrier imagewise. I have.

  The charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using the charger. The charger is not particularly limited and may be appropriately selected depending on the purpose. For example, a known contact charging device including a conductive or semiconductive roll, brush, film, rubber blade, etc. And non-contact chargers using corona discharge such as corotron, scorotron, etc., and known contact charging provided with conductive or semiconductive rolls, brushes, films, rubber blades, etc. A charger or a proximity charger is preferably used.

  The exposure can be performed, for example, by exposing the surface of the latent electrostatic image bearing member imagewise using the exposure device. The exposure device is not particularly limited as long as it can expose the surface of the electrostatic latent image carrier charged by the charger so as to form an image to be formed, and is appropriately selected according to the purpose. For example, various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system can be used. In the present invention, a back light system in which imagewise exposure is performed from the back side of the electrostatic latent image carrier may be employed.

-Development process and development means-
The developing step is a step of developing the electrostatic latent image using the toner or the developer of the present invention to form a visible image. The visible image can be formed, for example, by developing the electrostatic latent image using the toner or the developer of the present invention, and can be performed by the developing unit. The developing means is not particularly limited as long as it can be developed using, for example, the toner or developer of the present invention, and can be appropriately selected from known ones. For example, the toner of the present invention The toner container and the toner container according to the present invention are preferably exemplified by at least a developer containing a developer and capable of bringing the toner or the developer into contact or non-contact with the electrostatic latent image. A developing device including a cartridge is more preferable.

  The developing device may be of a dry development type, may be a single color developing device, or may be a multicolor developing device, for example, the toner or the developer. Preferable examples include a stirrer that is charged by frictional stirring and a rotatable magnet roller.

  In the developing device, for example, the toner and the carrier are mixed and agitated, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state to form a magnetic brush. . Since the magnet roller is disposed in the vicinity of the electrostatic latent image carrier (photoconductor), a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is electrically attracted. It moves to the surface of the electrostatic latent image carrier (photoconductor) by force. As a result, the electrostatic latent image is developed with the toner, and a visible image is formed with the toner on the surface of the electrostatic latent image carrier (photoconductor).

  The developer accommodated in the developing device is a developer containing the toner of the present invention, but the developer may be a one-component developer or a two-component developer. The toner contained in the developer is the toner of the present invention.

-Transfer process and transfer means-
The transfer step is a step of transferring the visible image to a recording medium. The intermediate transfer member may or may not be used, but the intermediate transfer member is used and the visible image is transferred onto the intermediate transfer member. A mode in which the visible image is secondarily transferred onto the recording medium after the primary transfer is preferable. The toner is composed of two or more colors, preferably a full color toner, and the visible image is transferred onto the intermediate transfer member to form a composite. An embodiment including a primary transfer step of forming a transfer image and a secondary transfer step of transferring the composite transfer image onto a recording medium is more preferable.
The transfer can be performed, for example, by charging the electrostatic latent image carrier (photoconductor) with a transfer charger using the visible image, and can be performed by the transfer unit. The transfer means includes a primary transfer means for transferring a visible image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer means for transferring the composite transfer image onto a recording medium. Embodiments are preferred. The intermediate transfer member is not particularly limited and may be appropriately selected from known transfer members according to the purpose. For example, a transfer belt and the like are preferable.

  The transfer means (the primary transfer means and the secondary transfer means) is a transfer for peeling and charging the visible image formed on the electrostatic latent image carrier (photoconductor) to the recording medium side. It is preferable to have at least a vessel. There may be one transfer means or two or more transfer means. Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device. The recording medium is not particularly limited and can be appropriately selected from known recording media (recording paper).

-Fixing process and fixing means-
The fixing step is a step of fixing the visible image transferred to the recording medium using a fixing device, and may be performed each time the toner of each color is transferred to the recording medium, or for the toner of each color. You may perform this simultaneously in the state which laminated | stacked this. There is no restriction | limiting in particular as said fixing device, Although it can select suitably according to the objective, A well-known heating-pressing means is suitable. Examples of the heating and pressing means include a combination of a heating roller and a pressure roller, a combination of a heating roller, a pressure roller, and an endless belt. The heating in the heating and pressing means is usually preferably 80 ° C to 200 ° C.
In the present invention, for example, a known optical fixing device may be used together with or in place of the fixing step and the fixing unit depending on the purpose.

-Static elimination process and static elimination means-
The neutralization step is a step of performing neutralization by applying a neutralization bias to the electrostatic latent image carrier, and can be suitably performed by a neutralization unit. The neutralization means is not particularly limited, and may be appropriately selected from known neutralizers as long as it can apply a neutralization bias to the electrostatic latent image carrier. Preferably mentioned.

-Cleaning process and cleaning means-
The cleaning step is a step of removing the toner remaining on the electrostatic latent image carrier, and can be suitably performed by a cleaning unit having the cleaning blade of the present invention. The cleaning means is not particularly limited as long as it uses the cleaning blade, and it is sufficient that the residual toner particles remaining on the electrostatic latent image carrier can be removed. You can choose.

-Recycling process and recycling means-
The recycling step is a step of recycling the electrophotographic (color) toner removed by the cleaning step to the developing unit, and can be suitably performed by the recycling unit.
There is no restriction | limiting in particular as said recycling means, A well-known conveyance means etc. are mentioned.

-Control process and control means-
The control means is a process for controlling the steps, and can be suitably performed by the control means.
The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.

One mode of carrying out the image forming method of the present invention by the image forming apparatus of the present invention (for example, the image forming apparatus shown in FIGS. 4 to 6) will be described with reference to FIG.
An image forming apparatus (100) shown in FIG. 4 includes a photosensitive drum (10) as the electrostatic latent image carrier (hereinafter referred to as “photosensitive body 10”), a charging roller (20) as the charging unit, An exposure device (30) as the exposure means, a development device (40) as the development means, an intermediate transfer member (50), a cleaning device (60) as the cleaning means having a cleaning blade, and the charge eliminating device A neutralizing lamp (70) as a means.

  The intermediate transfer member (50) is an endless belt, and is designed to be movable in the direction of the arrow by three rollers (51) that are arranged on the inner side and stretch the belt. A part of the three rollers (51) also functions as a transfer bias roller capable of applying a predetermined transfer bias (primary transfer bias) to the intermediate transfer member (50). A cleaning device (90) having a cleaning blade is disposed in the vicinity of the intermediate transfer member (50), and a developed image (image-forming particle image) is transferred to a transfer sheet (95) as a final transfer material. A transfer roller (80) as the transfer means capable of applying a transfer bias for (secondary transfer) is disposed to face the transfer roller. Around the intermediate transfer member (50), there is a corona charger (58) for applying a charge to the toner image on the intermediate transfer member (50) in the rotational direction of the intermediate transfer member (50). (10) and the intermediate transfer member (50) and the contact portion between the intermediate transfer member (50) and the transfer paper (95).

  The developing device (40) includes a developing belt (41) as the developer carrier, a black developing unit (45K), a yellow developing unit (45Y), and a magenta developing unit (45M) provided around the developing belt (41). ) And a cyan developing unit (45C). The black developing unit (45K) includes a developer accommodating portion (42K), a developer supply roller (43K), and a developing roller (44K). The yellow developing unit (45Y) includes a developer accommodating portion ( 42Y), a developer supply roller (43Y), and a development roller (44Y). The magenta development unit (45M) includes a developer container (42M), a developer supply roller (43M), and a development roller (44M). The cyan developing unit (45C) includes a developer container (42C), a developer supply roller (43C), and a developing roller (44C). Further, the developing belt (41) is an endless belt, is rotatably stretched around a plurality of belt rollers, and a part thereof is in contact with the photoreceptor (10).

  In the image forming apparatus (100) shown in FIG. 4, for example, the charging roller (20) uniformly charges the photosensitive drum (10). An exposure device (30) performs imagewise exposure on the photosensitive drum (10) to form an electrostatic latent image. The electrostatic latent image formed on the photosensitive drum (10) is developed by supplying toner from the developing device (40) to form a visible image (image forming particle image). The visible image (toner image) is transferred (primary transfer) onto the intermediate transfer member (50) by the voltage applied from the roller (51), and further transferred onto the transfer paper (95) (secondary transfer). The As a result, a transfer image is formed on the transfer paper (95). The residual toner on the photoconductor (10) is removed by the cleaning device (60) having the cleaning blade of the present invention, and the charge on the photoconductor (10) is once removed by the charge eliminating lamp (70).

  Another mode for carrying out the image forming method of the present invention by the image forming apparatus of the present invention will be described with reference to FIG. The image forming apparatus (100) shown in FIG. 5 does not include the developing belt (41) in the image forming apparatus (100) shown in FIG. 4, and a black developing unit (45K), yellow, is provided around the photoreceptor (10). Except that the developing unit (45Y), the magenta developing unit (45M), and the cyan developing unit (45C) are directly opposed to each other, the image forming apparatus (100) shown in FIG. The same effect is shown. In FIG. 5, the same components as those in FIG. 4 are denoted by the same reference numerals.

Another mode for carrying out the image forming method of the present invention by the image forming apparatus of the present invention will be described with reference to FIG. The tandem image forming apparatus (120) shown in FIG. 6 is a tandem color image forming apparatus. The tandem image forming apparatus (120) includes a copying apparatus main body (150), a paper feed table (200), a scanner (300), and an automatic document feeder (ADF) (400). The copying machine main body (150) is provided with an endless belt-like intermediate transfer member (50) at the center. The intermediate transfer member (50) is stretched around the support rollers (14), (15) and (16), and can be rotated clockwise in FIG. An intermediate transfer body cleaning device (17) for removing residual toner on the intermediate transfer body (50) is disposed in the vicinity of the support roller (15). The intermediate transfer member (50) stretched between the support roller (14) and the support roller (15) has four image forming units (18) of yellow, cyan, magenta, and black along the conveyance direction. A tandem developing device (120) arranged opposite to each other is arranged. An exposure device (21) is disposed in the vicinity of the tandem developing device (120). A secondary transfer device (22) is disposed on the side of the intermediate transfer member (50) opposite to the side on which the tandem developing device (120) is disposed. In the secondary transfer device (22), a secondary transfer belt (24), which is an endless belt, is stretched between a pair of rollers (23), and a transfer sheet conveyed on the secondary transfer belt (24); The intermediate transfer member (50) can contact each other. A fixing device (25) is disposed in the vicinity of the secondary transfer device (22). The fixing device (25) includes a fixing belt (26) that is an endless belt, and a pressure roller (27) that is pressed against the fixing belt (26).
In the tandem image forming apparatus (120), in the vicinity of the secondary transfer device (22) and the fixing device (25), sheet reversal is performed for reversing the transfer paper in order to form an image on both sides of the transfer paper. A device (28) is arranged.

  Next, full color image formation (color copying) using the tandem developing device (120) will be described. That is, first, a document is set on the document table (130) of the automatic document feeder (ADF) (400) or the automatic document feeder (400) is opened and the contact glass (32) of the scanner (300) is opened. A document is set on the document and the automatic document feeder (400) is closed.

  When a start switch (not shown) is pressed, when a document is set on the automatic document feeder (400), the document is transported and moved onto the contact glass (32). ) Immediately after the document is set on the scanner (300), the first traveling body (33) and the second traveling body (34) travel. At this time, light from the light source is irradiated by the first traveling body (33) and reflected light from the document surface is reflected by the mirror in the second traveling body (34), and is read through the imaging lens (35). The color original (color image) is read at (36), and is read as black, yellow, magenta and cyan image information.

  Each image information of black, yellow, magenta and cyan is stored in each image forming means (18) (black image forming means, yellow image forming means, magenta image forming means and cyan in the tandem developing device (120). Image forming means), and each toner image of black, yellow, magenta and cyan is formed in each image forming means. The black image, the yellow image, the magenta image, and the cyan image formed in this way are transferred onto the intermediate transfer member (50) that is rotationally moved by the support rollers (14), (15), and (16) in FIG. The black image formed on the black photoconductor (10K), the yellow image formed on the yellow photoconductor (10Y), the magenta image formed on the magenta photoconductor (10M), and the cyan photoconductor, respectively. The cyan image formed on the body (10C) is sequentially transferred (primary transfer). Then, the black image, the yellow image, the magenta image, and the cyan image are superimposed on the intermediate transfer member (50) to form a composite color image (color transfer image).

On the other hand, in the paper feed table (200), one of the paper feed rollers (142) is selectively rotated so that the sheet (recording paper) is fed from one of the paper feed cassettes (144) provided in the paper bank (143). ), Separated one by one by the separation roller (145), sent to the paper feed path (146), and conveyed by the conveyance roller (147) to the paper feed path (148) in the copier body (150). Guide and stop against the registration roller (49). Alternatively, the sheet feed roller (142) is rotated to feed out the sheets (recording paper) on the manual feed tray (54), separated one by one by the separation roller (52), and put into the manual feed path (53). Stop against the registration roller (49). The registration roller (49) is generally used while being grounded, but may be used in a state where a bias is applied to remove paper dust from the sheet.
Then, the registration roller (49) is rotated in synchronization with the synthesized color image (color transfer image) synthesized on the intermediate transfer member (50), and the intermediate transfer member (50), the secondary transfer device (22), The sheet (recording paper) is fed between the sheets, and the composite color image (color transfer image) is transferred (secondary transfer) onto the sheet (recording paper) by the secondary transfer device (22). A color image is transferred and formed on (recording paper). The residual toner particles on the intermediate transfer member 50 after image transfer are cleaned by the intermediate transfer member cleaning device (17).

  The sheet (recording paper) on which the color image has been transferred is conveyed by the secondary transfer device (22) and sent to the fixing device (25). In the fixing device (25), heat and pressure are applied. The composite color image (color transfer image) is fixed on the sheet (recording paper). Thereafter, the sheet (recording paper) is switched by the switching claw (55) and discharged by the discharge roller (56) and stacked on the discharge tray (57), or switched by the switching claw (55) and the sheet is reversed. The image is reversed by the device (28) and guided again to the transfer position, and an image is recorded also on the back surface. Then, the image is discharged by the discharge roller (56) and stacked on the discharge tray (57).

  In the image forming apparatus of the present invention, since the toner of the present invention is used, a high-quality image can be efficiently obtained and good residual toner can be cleaned.

FIG. 7 specifically shows a schematic view of an image forming apparatus equipped with the process cartridge of the present invention.
In the image forming apparatus equipped with the developing cartridge holding the toner or the developer of the present invention and the process cartridge having the cleaning means using the cleaning blade of the present invention, the photosensitive member is rotationally driven at a predetermined peripheral speed. . In the rotation process, the photosensitive member is uniformly charged with a positive or negative predetermined potential on its peripheral surface by the charging unit, and then receives image exposure light from an image exposing unit such as slit exposure or laser beam scanning exposure. An electrostatic latent image is sequentially formed on the peripheral surface of the body, and the formed electrostatic latent image is then developed with toner by a developing unit, and the developed toner image is transferred between the photosensitive member and the transfer unit from the paper feeding unit. Then, the image is sequentially transferred to the transfer material fed in synchronization with the rotation of the photosensitive member by the transfer means. The transfer material that has received the image transfer is separated from the surface of the photosensitive member, introduced into the image fixing means, and fixed on the image, and printed out as a copy (copy). The surface of the photoreceptor after the image transfer is cleaned by removing the transfer residual toner by the cleaning means using the cleaning blade of the present invention, and after being further neutralized, it is repeatedly used for image formation.

  In the process cartridge of the present invention, since the residual toner from the toner or developer of the present invention is cleaned, it has the above-described effects and can be mounted on the image forming apparatus. An image forming apparatus with good exchangeability can be provided.

(Polyol resin 1)
In a separable flask equipped with a stirrer, a thermometer, an N ₂ inlet, and a cooling tube, 378.4 g of a low molecular bisphenol A type epoxy resin (number average molecular weight: about 360), a high molecular bisphenol A type epoxy resin (number average molecular weight: About 2700) 86.0 g, 191.0 g of bisphenol A-type propylene oxide adduct, 274.5 g of bisphenol A, 70.1 g of p-cumylphenol, and 200 g of xylene were added. The temperature was raised to 70 to 100 ° C. in an N ₂ atmosphere, 0.183 g of lithium chloride was added, the temperature was further raised to 160 ° C., water was added under reduced pressure, and water and xylene were bubbled to make water, xylene, etc. Volatile components and polar solvent-soluble components are removed and polymerized at a reaction temperature of 180 ° C. for 6 to 9 hours, Mn: 3800, Mw / Mn: 3.9, Mp: 5000, softening point 109 ° C., Tg 58 ° C. Then, 1000 g of a polyol resin having an epoxy equivalent of 20000 or more was obtained (polyol resin 1). The reaction conditions were controlled so that no monomer component remained in the polymerization reaction. The polyoxyalkylene part of the main chain was confirmed by NMR.

(Polyol resin 2)
The blending of the polyol resin 1 was adjusted to obtain 1000 g of a polyol resin having Mn; 3500, Mw / Mn; 3.3, Mp; 4500, a softening point of 101 ° C., Tg of 53 ° C., and an epoxy equivalent of 20000 or more (polyol resin 2).

(Manufacture of toner)
<Colored particles 1, colored particles 2>
Water 1000 parts Phthalocyanine green hydrous cake (solid content 30%) 200 parts Carbon black (# 44 manufactured by Mitsubishi Chemical Corporation) 540 parts Polyol resin 1 600 parts The above raw materials are mixed in a Henschel mixer, and water soaks into the pigment aggregate. Got a mixture. This was kneaded for 45 minutes with two rolls set at a roll surface temperature of 100 ° C., rolled and cooled, and pulverized with a pulverizer to obtain a master batch pigment.
Polyol resin 1 95 parts Master batch 10 parts Charge control agent (Bontron E-84 manufactured by Orient Chemical Co., Ltd.) 2 parts Wax (fatty acid ester wax, melting point 83 ° C., viscosity 280 mPa · s (90 ° C.)) 5 parts After mixing, the mixture was melt-kneaded for 30 minutes with a two-roll mill, and the kneaded product was rolled and cooled. Then, using a collision plate type crusher (I type mill; manufactured by Nippon Pneumatic Industry Co., Ltd.) using a jet mill and a wind classifier (DS classifier; manufactured by Nippon Pneumatic Industry Co., Ltd.) using a swirling flow, the production conditions were changed, The following black colored particles were obtained.
Colored particles 1: volume average particle size 5.3 μm
Colored particles 2: Volume average particle size 5.5 μm

<Colored particles 3, colored particles 4>
The polyol resin 1 of the black toner 1 was replaced with the polyol resin 2 to obtain black colored particles having a volume average particle size of 5.2 μm and 5.4 μm.

<Black toner 1 to black toner 4>
Resin fine particles (MP-1000 average particle size 0.4 μm, manufactured by Soken Chemical Co., Ltd.) are mixed with the colored particles 1 to 4, and the spheroidization treatment is performed using the surffusion system (manufactured by Hosokawa Micron Corporation) under different conditions. Black toner particles having an average circularity were obtained.
Black toner 1: volume average particle size 5.5 μm, average circularity 0.97
Black toner 2: Volume average particle size 5.8 μm, average circularity 0.97
Black toner 3: Volume average particle size 5.2 μm, average circularity 0.96
Black toner 4: Volume average particle size 5.7 μm, average circularity 0.98
The toner characteristics are shown below.

得られたトナーの空間率とトルクの関係を図３に示す。

FIG. 3 shows the relationship between the space ratio and torque of the obtained toner.

(Additive mixture)
Toners 1 to 4 were obtained by mixing 1.0 wt% of HDK-H2000 (primary particle diameter 12 nm) (manufactured by Clariant Japan) as inorganic fine particles with black toners 1 to 4.
Black toner 1 and 2 were mixed with 0.5 wt% of HDK-H2000 (primary particle size 12 nm) (manufactured by Clariant Japan) and 1.0 part of spherical silica (average particle size 150 nm) as inorganic fine particles to obtain toner 5. .
Black toner 1 was mixed with 0.5 wt% of HDK-H2000 (primary particle size 12 nm) (manufactured by Clariant Japan) and 1.0 part of spherical silica (average particle size 100 nm) as inorganic fine particles to obtain toner 6.
Black toner 1 is mixed with 0.5 wt% of HDK-H2000 (primary particle size 12 nm) (manufactured by Clariant Japan) as inorganic fine particles and 0.5 part of spherical acrylic resin (average particle size 2.2 microns) to prepare toner 7. Obtained.
Black toner 1 was mixed with 0.5 wt% of HDK-H2000 (primary particle size 12 nm) (manufactured by Clariant Japan) and 1.0 part of spherical silica (average particle size 150 nm) as inorganic fine particles to obtain toner 8.

<Creation of cleaning blade 1>
After mixing 5 parts by weight of spherical titanium oxide fine particles having an average particle diameter of 100 nm with 100 parts by weight of a liquid prepolymer for urethane rubber, a curing agent is added, and using these mixtures, a sheet is formed using a centrifugal molding machine. A product was produced. The obtained sheet was cut out to obtain a cleaning blade.

<Creation of cleaning blades 2-5>
Cleaning blade 2 was obtained by using 5 parts by weight of acicular titanium oxide having a major axis of 2 microns and a thickness of 0.1 microns instead of spherical titanium oxide in the production of cleaning blade 1.
Cleaning blade 3 was obtained by using 5 parts by weight of acicular calcium carbonate having a major axis of 3 microns and a thickness of 0.2 microns instead of spherical titanium oxide in the production of cleaning blade 1.
Cleaning blade 4 was obtained by using 3 parts by weight of an acrylic-modified polyorganosiloxane having an average particle size of 3.2 microns instead of spherical titanium oxide in the production of cleaning blade 1.
The cleaning blade 5 was obtained without using spherical titanium oxide in the production of the cleaning blade 1.

<Creation of cleaning blades 6-7>
Cleaning blade 6 was obtained by using 5 parts by weight of titanium oxide having an average particle size of 0.05 microns instead of spherical titanium oxide in the production of cleaning blade 1.
Cleaning blade 7 was obtained by using 5 parts by weight of titanium oxide having an average particle size of 5.5 microns instead of spherical titanium oxide in the production of cleaning blade 1.

(Trial manufacture of photoconductor)
A coat layer in which 3 parts by weight of an acrylic-modified polyorganosiloxane was dispersed in 100 parts by weight of polycarbonate was uniformly applied to the outermost surface of the IPSIO-CX8800 photoreceptor to a thickness of 2.5 microns. The obtained photoreceptor is designated as photoreceptor 2.
The photoreceptor for IPSIO-CX8800 is referred to as photoreceptor 1.

The obtained toner and the cleaning blade were evaluated using an electrophotographic printer IPSIO-CX8800 manufactured by Ricoh Co., Ltd.
The CX8800 was compared with a case where a lubricant supply mechanism for the photoconductor was attached and a case where it was removed. Note that CX8800 is applied such that the lubricant is rubbed with a brush rather than sprayed with particles. The lubricant is held in the apparatus as a rod-like solid.
The evaluation was performed on the cleaning property after forming 10,000 sheets of images in three environments with different temperatures and humidity. First, 10,000 images were formed in an environment of 21 ° C. and 50%, then 10,000 images were formed in a low temperature environment of 10 ° C. and 15%, and finally 10,000 sheets in a high humidity environment of 30 ° C. and 85%. Image formation was performed.
The results were as follows: ◎: very good, ○: good, △: not good, ×: bad.
The results are shown below.
In the above embodiment, the toner surface properties were changed by adjusting the degree of mixing and holding the resin particles on the toner surface, and the parameters defined in the present invention could be easily obtained.

本発明の構成とすることで、環境が変化し、かつ、多数枚画像形成を行なった後にも、良好な画像形成を行なうことができた。

By adopting the configuration of the present invention, the environment was changed, and good image formation could be performed even after a large number of images were formed.

1 is a schematic configuration diagram of a conical rotor type toner fluidity evaluation apparatus used in the practice of the present invention. FIG. 3 is a diagram schematically illustrating a toner shape. FIG. 6 is a diagram illustrating a relationship between a toner space ratio and torque. 1 is a schematic diagram illustrating an example of an image forming apparatus that performs an image forming method of the present invention. It is the schematic which shows the other example of the image forming apparatus which enforces the image forming method of this invention. 1 is a schematic view showing an example of an image forming apparatus (tandem color image forming apparatus) for carrying out an image forming method of the present invention. 1 is a schematic view of an image forming apparatus equipped with a process cartridge of the present invention.

Explanation of symbols

10 Photoconductor (Photoconductor drum)
10K black photoconductor 10Y yellow photoconductor 10M magenta photoconductor 10C cyan photoconductor 14 support roller 15 support roller 16 support roller 17 intermediate transfer cleaning device 18 image forming means 20 charging roller 21 exposure device 22 secondary transfer device 23 Roller 24 Secondary transfer belt 25 Fixing device 26 Fixing belt 27 Pressure belt 28 Sheet reversing device 30 Exposure device 32 Contact glass 33 First traveling body 34 Second traveling body 35 Imaging lens 36 Reading sensor 40 Developing device 41 Developing belt 42K Developer container 42Y Developer container 42M Developer container 42C Developer container 43K Developer supply roller 43Y Developer supply roller 43M Developer supply roller 43C Developer supply roller 44K Development roller 44Y Development roller 44M Development roller 44C Development roller 5K black developing device (unit)
45Y Yellow developer unit
45M Magenta developer unit
45C Cyan developer (unit)
49 Registration roller 50 Intermediate transfer member 51 Roller 52 Separation roller 53 Manual feed path 54 Manual feed tray 55 Switching claw 56 Discharge roller 57 Discharge tray 58 Corona charger 59 Charger 60 Cleaning device 70 Static elimination lamp 80 Transfer roller 90 Cleaning device 95 Transfer Paper 100 Image forming apparatus 110 Belt-type fixing device 120 Tandem type developing device 130 Document base 142 Paper feed roller 143 Paper bank 144 Paper feed cassette 145 Separating roller 146 Paper feed path 147 Transport roller 148 Paper feed path 150 Copying apparatus main body 200 Paper feed Table 300 Scanner 400 Automatic document feeder (ADF)

Claims (18)

A charging step of charging the latent image carrier by bringing a charging member into contact with or close to the surface of the latent image carrier carrying the latent image; a latent image forming step of forming a latent image on the latent image carrier; A latent image carrier is formed by forming a transfer electric field between a developing process in which toner is attached to the latent image on the image carrier and developing, and a surface moving member that moves while contacting the latent image carrier. A transfer step for transferring the toner image formed on the recording material sandwiched between the surface moving member or the surface moving member, and a cleaning step for cleaning the toner remaining on the latent image carrier with a cleaning blade The toner comprises a toner powder layer after uniformly pressing and compressing a powder phase of toner particles comprising at least a resin and a pigment and having an average circularity of 0.95 or more. Space factor X and cone in toner powder layer The torque value Y of the conical rotor generated when the conical rotor rotates and moves in the powder layer satisfies the relationship [Y ≧ −0.05X + 0.029]. An image forming method, wherein the cleaning blade disperses a filler having an average particle size of 0.1 to 5.0 μm. The image forming method according to claim 1, wherein a filler of the cleaning blade is made of titanium oxide or calcium carbonate. The image forming method according to claim 1, wherein the filler of the cleaning blade has a needle shape. The image forming method according to claim 3, wherein the cleaning blade further includes a spherical filler as the filler. 2. The image forming method according to claim 1, wherein the filler of the cleaning blade is an acrylic-modified polyorganosiloxane. 6. The image forming method according to claim 1, further comprising a step of supplying organic or inorganic fine particles having an average particle diameter of 80 nm or more and 2.0 μm or less to the surface of the latent image carrier. The image forming method according to claim 6, wherein the toner is added with organic or inorganic fine particles having an average particle diameter of 80 nm to 2.0 μm. The image forming method according to claim 1, further comprising a lubricant supplying step of supplying a lubricant to the surface of the latent image carrier so that a coefficient of friction of the surface of the photosensitive member is 0.2 or less. 9. The image forming method according to claim 1, wherein the latent image carrier has an acrylic modified polyorganosiloxane dispersed on a surface thereof. A latent image carrier that carries a latent image, a charging device that charges the latent image carrier by bringing a charging member into contact with or close to the surface of the latent image carrier, and a latent image forming device that forms a latent image on the latent image carrier A transfer electric field is formed between the latent image carrier and the developing device for developing the toner by attaching the toner to the latent image on the latent image carrier and the surface moving member that moves while contacting the latent image carrier. A transfer device that transfers the toner image formed on the carrier onto the recording material sandwiched between the surface moving member or the surface moving member, and the toner remaining on the latent image carrier are cleaned with a cleaning blade. And a toner powder obtained by uniformly pressing and compressing a powder phase of toner particles having an average circularity of 0.95 or more and comprising at least a resin and a pigment. Layer space ratio X and toner powder layer The torque value Y of the conical rotor generated when the conical rotor is caused to enter while rotating and the conical rotor rotates in the powder layer satisfies the relationship [Y ≧ −0.05X + 0.029]. An image forming apparatus, wherein the cleaning blade is dispersed with a filler having an average particle size of 0.1 to 5.0 μm.
The image forming apparatus according to claim 10, wherein a filler of the cleaning blade is made of titanium oxide or calcium carbonate. The image forming method according to claim 10, wherein the cleaning blade has a needle-like filler. The image forming method according to claim 12, wherein the cleaning blade further includes a spherical filler as the filler. The image forming apparatus according to claim 10, wherein a filler of the cleaning blade is an acrylic-modified polyorganosiloxane. 15. The image forming apparatus according to claim 10, wherein organic or inorganic fine particles having an average particle diameter of 80 nm to 2.0 μm are supplied to the surface of the latent image carrier. The image forming apparatus according to claim 15, wherein the toner is one to which organic or inorganic fine particles having an average particle diameter of 80 nm to 2.0 μm are added. The image forming apparatus according to claim 10, further comprising a lubricant supplying unit that supplies a lubricant to the surface of the latent image carrier to make a coefficient of friction of the surface of the photosensitive member 0.2 or less. 18. The image forming apparatus according to claim 10, wherein the latent image carrier has an acrylic modified polyorganosiloxane dispersed on a surface thereof.

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