JP2015043017A - Carrier coating liquid reservoir and feeder, carrier, developer, replenishment developer and process cartridge - Google Patents

Abstract

An object of the present invention is to provide a stable charge imparting ability over a long period of time, excellent wear resistance, little change in carrier resistance, no carrier adhesion in a solid image portion due to a decrease in resistance over time, and a background in a non-image portion Provided is a carrier liquid storage / feed device capable of producing a carrier that does not cause fogging. A storage liquid feeding device for storing a coating liquid for coating a core material of a carrier and supplying the coating liquid to a coating apparatus, wherein the coating liquid for coating includes at least a binder resin and particles, and has a horizontal cross section. A stirring tank having a circular shape, a baffle provided in the stirring tank, and a stirring main wing for stirring the coating liquid for coating, the maximum area S2 of the height component of the stirring wing Is a storage and feeding device for the coating liquid for coating the carrier, which is 25% to 70% with respect to the maximum effective surface area S1 of the stirring main wing. [Selection] Figure 2

Description

  The present invention relates to a storage liquid supply device for a coating liquid for coating a carrier, a carrier, a developer, a replenishing developer, and a process cartridge.

In electrophotographic image formation, an electrostatic latent image is formed by an electrostatic charge on an image carrier such as a photoconductive material, and a charged toner particle is attached to the electrostatic latent image to form a visible image. Thereafter, the visible image is transferred to a recording medium such as paper and fixed, and an output image is obtained.
In recent years, copying and printer technologies using an electrophotographic system are rapidly expanding from monochrome to full color, and the full color market tends to expand. Color image formation by full-color electrophotography generally reproduces all colors by stacking three color toners of three primary colors, yellow, magenta and cyan, or four color toners with black toner added thereto. is there. For this reason, in order to obtain a clear full-color image having excellent color reproducibility, it is necessary to smooth the fixed toner image surface to some extent to reduce light scattering. For these reasons, the image gloss of conventional full-color copying machines and the like is often 10% to 50% of medium to high gloss.

  In general, as a method for fixing a dry toner image on a recording medium, a contact heating fixing method in which a roller or belt having a smooth surface is heated and pressed against the toner is frequently used. This method has high thermal efficiency and high-speed fixing, and is advantageous in that it can give gloss and transparency to the color toner. However, the surface of the heat-fixing member is brought into contact with the molten toner under pressure. Since the toner image is peeled from the surface of the post-heating fixing member, a so-called offset phenomenon occurs in which a part of the toner image adheres to the surface of the heat fixing member and is transferred onto another image. For the purpose of preventing this offset phenomenon, there is a method in which the surface of the heat fixing member is formed of silicone rubber or fluorine resin having excellent releasability, and further, a release oil such as silicone oil is applied to the surface of the heat fixing member. Generally adopted. However, this method is extremely effective in preventing toner offset, but requires a device for supplying release oil, and is unsuitable for downsizing the machine due to the increase in size of the fixing device. For this reason, in the case of a monochrome toner, the viscosity of the toner when melted is adjusted by adjusting the molecular weight distribution of the binder resin so that the melted toner does not break internally, and a release agent such as wax is further included in the toner. Therefore, there is a tendency to employ a method in which the release oil is not applied to the fixing roller (oilless), or the amount of oil applied is very small.

  On the other hand, in the case of color toners, as in the case of monochrome toners, there is a tendency toward oil-less for the purpose of downsizing the machine and simplifying the configuration. However, as described above, in order to improve the color reproducibility of the color toner, it is necessary to smooth the surface of the fixed image. Therefore, the viscoelasticity at the time of melting must be lowered. It is easier to offset than toner, making it more difficult for the fixing device to be oil-less or to be applied in a small amount. In addition, when a release agent is contained in the toner, the adhesion of the toner increases and the transferability to the transfer paper decreases. Further, the release agent in the toner contaminates the frictional charging member such as a carrier and lowers the chargeability, resulting in a problem that the durability is lowered.

On the other hand, regarding the carrier, there is an increasing demand for faster and more beautiful image formation, but with the recent increase in machine speed, the stress received by the developer containing the carrier and toner has also increased dramatically. Even in a carrier that has been made to have a long life, a sufficient life cannot be obtained. On the other hand, in terms of high image quality, as the toner diameter and carrier diameter are reduced, the allowable range of the image quality with respect to the charge amount distribution is narrowing, especially with respect to toner contamination (background fogging) in non-image areas. Is very likely to be a defective image.
Furthermore, in the case of a developer in which maintenance is facilitated by adding wax to the toner, the amount of toner spent is extremely large, the toner charge amount is reduced, the margin for toner scattering and background contamination is reduced, Improvements in carrier chargeability, resistance controllability, and durability are important.

  In a full-color electrophotographic system, if the carrier toner spent or the coating film is scraped (peeled off), the carrier resistance and the developer pumping amount change, and the image density, particularly the density in the highlight area, changes. The current situation is that it cannot be maintained. In addition, color stains occur due to the removal of the filler due to scraping (peeling) of the coating film, and thus there is a problem that high quality cannot be maintained with the color toner.

In order to solve the above problem, attempts have been made to include conductive particles in the binder resin covering the carrier. As the conductive particles, for example, conductive particles in which the surface of inorganic pigment particles is coated with tin dioxide and further coated with an indium oxide layer containing tin dioxide have been proposed (see Patent Documents 1 and 2).
However, the proposed conductive particles have a high specific gravity, and in coating liquids containing a binder resin, a cylindrical stirring tank, a flat blade type, an anchor type stirring blade used in a conventional slurry stirrer are used. There is a problem that even if stirring is performed, the conductive particles settle. This is because, in the agitator, a circulating flow in the rotating direction with weak agitation strength is generated, and those having a large specific gravity, such as conductive particles, have a higher sedimentation speed due to gravity than buoyancy due to agitation. It is because it ends.
When the conductive particles settle, there is a problem that the concentration ratio of the conductive particles in the coating film varies depending on the location when the coating film is formed on the core material of the carrier. This leads to a decrease in the durability of the carrier and variations in quality. For example, in a place where the abundance ratio of conductive particles is large, the coating film is missing due to the detachment of the particles, and the core material is exposed. As a result, the charge imparting ability of the carrier and the change in the resistance of the carrier increase, the occurrence of carrier adhesion in the solid image portion due to the decrease in resistance over time, the toner stain (background fogging) in the non-image portion, There is a problem that it becomes a defect image.

  Therefore, it has a stable charge imparting ability for a long period of time, excellent wear resistance, little change in carrier resistance, no carrier adhesion in a solid image portion due to a decrease in resistance over time, and background fogging in a non-image portion Therefore, it is desired to provide a storage and feeding apparatus for a coating liquid for coating a carrier that can produce a carrier that does not cause the problem.

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, the present invention has a stable charge imparting ability over a long period of time, has excellent wear resistance, has little change in carrier resistance, does not cause carrier adhesion in a solid image portion due to a decrease in resistance over time, and is non-image. It is an object of the present invention to provide a storage liquid feeding device for a carrier coating liquid that can produce a carrier that does not cause background fogging.

As a means for solving the above-mentioned problems, a storage liquid feeding device for a coating liquid for coating a carrier according to the present invention,
A storage liquid feeding device for storing a coating liquid for coating that coats the core material of a carrier and supplying the coating liquid to a coating device,
The coating liquid for coating contains at least a binder resin and particles,
A stirring tank having a circular horizontal section;
A baffle provided in the stirring vessel;
A stirring main wing for stirring the coating liquid for coating,
Maximum area _{S 2} of the height component of the stirring wing is 25% to 70% of the maximum effective surface area _{S 1} of the stirring wing.

  According to the present invention, it has a stable charge-imparting ability over a long period of time, has excellent wear resistance, has little change in carrier resistance, and does not cause carrier adhesion in a solid image portion due to a decrease in resistance over time. It is possible to provide a device for storing and feeding a coating liquid for coating a carrier capable of producing a carrier that does not cause background fogging.

FIG. 1 is a schematic view showing an example of an entire storage liquid feeding device for a carrier coating coating liquid. FIG. 2 is a schematic cross-sectional view of a stirring tank in an example of a storage liquid feeding device for a carrier coating coating liquid. FIG. 3 is a schematic view of a stirring main wing in an example of a storage liquid feeding device for a carrier coating coating liquid. Figure 4 is an explanatory diagram for explaining a maximum area S ₀ of the horizontal cross section of the agitating tank. Figure 5 is an explanatory diagram for explaining a maximum effective surface area S ₁ of the stirring wing. Figure 6 is an explanatory diagram for explaining a maximum area S ₂ and the total area S ₃ of the stirring aileron height component of the stirring wing. FIG. 7 is a schematic perspective view showing another example of the stirring main wing. FIG. 8 is a schematic perspective view showing another example of the stirring main wing. FIG. 9 is a schematic view showing an example of the process cartridge of the present invention. FIG. 10 is a schematic diagram illustrating an example of an image forming apparatus used in the present invention. FIG. 11 is a schematic view showing another example of the image forming apparatus used in the present invention. FIG. 12 is a schematic view showing an example of still another image forming apparatus (tandem color image forming apparatus) used in the present invention. FIG. 13 is a partially enlarged schematic view of the image forming apparatus shown in FIG.

(Storage and feeding device for carrier coating liquid)
An apparatus for storing and feeding a coating liquid for coating a carrier of the present invention,
A stirring tank having a circular horizontal section;
A baffle provided in the stirring vessel;
And a stirring main wing for stirring the coating liquid for coating, and further includes other means as necessary.

As a result of intensive studies by the present inventors in order to solve the above-mentioned problems, a storage liquid feeding apparatus that stores a coating liquid for coating that coats the core material of a carrier and supplies the coating liquid to the coating apparatus, A stirring tank having a circular horizontal cross section; a baffle provided in the stirring tank; and a stirring main wing for stirring the coating liquid for coating; a maximum area S of a height component of the stirring wing _2, said 25% to 70% of the maximum effective surface area S ₁ of the stirring wing, preferably the maximum effective surface area S ₁ of the stirring wing is to the maximum area S ₀ of the horizontal cross-section of the stirring tank It has been found that a remarkable improvement effect can be obtained when the content is 5% to 20%.

  In the coating liquid for coating the carrier containing at least the binder resin and the particles, it is important to solve the problem that the particle concentration can be kept uniform and the ratio of the concentration of particles in the coating film is uniform. In addition, stable quality can be obtained by uniformly distributing the particles in the coating film. That is, by improving the concentration uniformity of the particles in the coating liquid for coating, it becomes possible to maintain the same coating film state at any location of the coating film when coating, (Even if any carrier particles are taken to be the same carrier particles), the charge amount distribution and the wear resistance can be drastically improved. Furthermore, since the particles are uniformly present in the coating film, the surface of the particles is reliably covered with the binder resin, which makes it difficult to detach. In addition, unlike the case where it exists in a large aggregated state, the coating film due to the desorption of particles is eliminated, and the core material is suppressed from being exposed. Therefore, it is possible to improve the carrier adhesion in the solid image portion and the toner stain (background fogging) in the non-image portion, which are the problems of the present invention.

  As a method of stirring and maintaining a uniform coating liquid containing particles with a large density and a binder resin, the swirling flow is dominant (flow with low stirring ability) only by the rotation of the stirring blade in the prior art. High density particles settle. Therefore, the baffle and the shape of the agitation tank were studied to form an up-and-down circulation flow (a flow having a high agitation ability with respect to particle sedimentation) for improvement. As a result, sedimentation of the particles was considerably prevented, but there was a problem in that the particles were settled due to dead space behind the baffle (relative to the flow direction). Furthermore, in the present invention, it has been found that by applying a force for forming a vertical circulating flow to the stirring main wing itself, a flow can also be formed in the dead space, and the particle concentration in the entire stirring tank can be kept uniform. did.

<Stirring tank>
There is no restriction | limiting in particular about the magnitude | size, a shape, a structure, a material, etc. as said stirring tank, According to the objective, it can select suitably. Examples of the material include metals such as stainless steel, aluminum, and iron.
The shape of the stirring tank is not particularly limited as long as the horizontal cross section is circular, and can be appropriately selected according to the purpose. Examples thereof include hemispherical, columnar, and cylindrical shapes.
There is no restriction | limiting in particular about the magnitude | size of the said stirring tank, The magnitude | size of the grade normally used is preferable.
There is no restriction | limiting in particular as a structure of the said stirring tank, Although it can select suitably according to the objective, It is preferable that it is a single layer structure or a 2 layer structure.

In the present invention, in view of the fact that the distribution of the particles in the coating film of the carrier is very important for the carrier quality, in order to distribute the particles uniformly in the coating film, the coating liquid for coating up to the coating apparatus is used. Need to be fed in a uniform state. However, since the particles in the coating liquid have a high specific gravity and sedimentation easily occurs, the particles may generate a force against gravity by stirring or the like to keep the particle concentration in the coating liquid uniform. preferable.
As an apparatus generally used for solid-liquid stirring, there is a stirring with a cylindrical stirring tank and a flat blade (or anchor blade) type stirring blade. However, in these stirring devices, only a circulating flow in the rotating direction is generated, and the circulating flow that is swept up and down is weak, so that particles having a high specific gravity are settled against the gravity.
Therefore, in order not to allow the particles to settle, it is important to form not only the circulating flow in the rotating direction but also the vertical circulating flow against gravity.
In addition, by using the hemispherical stirring tank, a flow pattern is formed along the spherical shape, and not only the circulation flow in the rotating direction but also the flow pattern of the circulating flow that is swung up and down is formed at the same time. The improvement effect is remarkable for prevention of sedimentation.

<Stirring wing>
The stirring main wing is a member for stirring the coating liquid for coating.
There is no restriction | limiting in particular about the magnitude | size, a shape, a structure, a material, etc. as said stirring main wing | blade, According to the objective, it can select suitably. Examples of the material include metals such as stainless steel, aluminum, and iron, and solvent resistant plastics such as Teflon (registered trademark).
There is no restriction | limiting in particular about the shape and magnitude | size of the said stirring main blade, The shape and magnitude | size of the grade normally used are preferable.
There is no restriction | limiting in particular as a structure of the said stirring main blade, Although it can select suitably according to the objective, It is preferable that it is a single layer structure or a two-layer structure.

  In the present invention, it is effective to use a pitched blade type stirring main blade. The pitched wing is a main wing characterized in that the blade is inclined with respect to the rotational direction. In contrast, there are flat wings (or anchor wings) in which the blades are perpendicular to the direction of rotation. In the flat blade (or anchor blade), the direction in which the stirring main blade discharges the coating liquid for coating is the same as the rotation direction, that is, only the flow pattern in the rotation direction. However, in the pitched blade type, since the stirring main blade is inclined, the stirring main blade discharges the coating liquid for coating not only in the turning direction but also in the vertical direction. A flow pattern can be formed, and settling of particles can be prevented.

In the present invention, the maximum area _{S 2} of the height of the component wherein the stirring wing is 25% to 70% of the maximum effective surface area _{S 1} of the stirring wing is preferably 35% to 60%. When the maximum area S ₂ of the height component of the stirring wing is less than 25% of the maximum effective surface area S ₁ of the stirring wing, that particles becomes insufficient vertical circulating flow causes to settle If it exceeds 70%, the swirling flow is weakened, which may cause unevenness of particles.
Herein, the maximum effective surface area S ₁ of the stirring wing, with respect to the rotation direction means the largest of the surface area of the agitating wing forming a discharge force for coating the coating liquid, indicated by S ₁ in FIG. 5 The surface area of the filled portion.
Maximum effective surface area S ₁ of the stirring wing may be calculated from the sum of the surface area at the time of projecting the stirring wing in the vertical direction. Specifically, in the case of FIG. 5, the maximum effective surface area S ₁ = 4 × a × α can be obtained.

The maximum area S ₂ of the height component of the stirring wing means the largest of the area of the height component of the stirring wing to form a vertical circulation flow, the fill portion indicated by S ₂ in FIG. 6 Surface area.
Maximum area S ₂ of the height component of the stirring wing may be calculated from the sum of the areas at the time of projecting the stirring wing in the horizontal direction. That is, it can be calculated from (outer diameter d of stirring main wing × height b of stirring main wing) in FIG. Note that the height b is constant even when the stirring main wing is inclined.

In the present invention, the maximum effective surface area S ₁ of the stirring main wing is preferably 5% to 20% with respect to the maximum area S ₀ of the horizontal section of the stirring tank. When the maximum effective surface area S ₁ of the stirring wing is less than 5% of the maximum area S ₀ of the horizontal cross section of the agitating tank, low stirring capability, would occur sedimentation of particles, forming a coating film of the carrier When it exceeds 20%, it may cause non-uniformity and cause carrier adhesion in a solid image portion due to a decrease in resistance over time, toner stain (background fogging) and solid carrier adhesion in a non-image portion. The stirring ability becomes excessive, which may cause uneven distribution of particles and change in physical properties of the binder resin due to excessive stirring.
Here, the maximum area S ₀ of the horizontal cross-section of the stirring vessel, means largest of the horizontal cross-sectional area of the stirring vessel (circle area), the surface area of the filled portion indicated by S ₀ in Fig.
Maximum area S ₀ of the horizontal cross-section of the stirring vessel can be measured by calculating the circle area.

The outer diameter d of the stirring main wing is preferably 15% to 40% with respect to the maximum inner diameter D of the stirring tank. This is because, as the outer diameter d of the stirring main wing increases, the stirring energy increases, so that a high stirring effect can be obtained. In addition, a coating liquid for coating with high viscosity requires a large amount of stirring energy, but this can also be handled.
When the outer diameter d of the stirring main wing is less than 15% of the maximum inner diameter D of the stirring tank, a sufficient stirring effect may not be obtained since the discharge ability of the coating liquid for coating is small, and exceeds 40%. In addition, the discharge ability of the coating liquid for coating may be too high, and the particles may be biased to the wall surface of the stirring tank due to centrifugal force, making uniform stirring difficult.
For the same reason, the height b of the stirring main wing is preferably 2.5% to 10% with respect to the maximum inner diameter D of the stirring tank.

The inclination angle θ1 of the stirring main wing is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 15 ° to 60 °, and more preferably 30 ° to 50 °.
When the inclination angle is less than 15 °, the area where the stirring main blade contacts the coating liquid for coating during rotation is small, and the discharge capacity is decreased, and the particles may settle in the coating liquid for coating. On the other hand, when the tilt angle θ1 exceeds 60 °, the circulating flow in the rotating direction becomes strong, the vertical circulating flow that is most effective for the sedimentation of the particles becomes weak, and the particles settle in the coating liquid for coating. May end up.
The inclination angle θ1 of the stirring main wing means the inclination angle of the stirring main wing with respect to the horizontal plane, and is indicated by an angle θ1 in FIG.

  The stirring main wing is not particularly limited and may be appropriately selected depending on the purpose, but is preferably a curved plate that is curved with respect to the rotation direction (see FIG. 7). The stirring main wing is preferably curved in a concave direction with respect to the rotational direction. Conventionally, a flat plate is used as the agitating main wing, but when the agitating main wing rotates and comes into contact with the coating liquid for coating, the vector is discharged in the vertical direction compared to the flat plate. The force can be increased and the effect of improvement on the sedimentation of the particles is greatly increased.

<Agitating auxiliary blade>
The stirring main wing preferably has a stirring auxiliary wing. One or a plurality of the stirring auxiliary blades may be formed on one stirring main blade.
By providing a stirring auxiliary blade on the stirring main blade, the discharge force of the coating liquid for coating in the direction of increasing the circulating flow in the vertical direction can be enhanced.
The stirring aileron total area _{S 3} of preferably 30% or less of the maximum effective surface area _{S 1} of the stirring wing, more preferably 15% to 25%. The stirring aileron total area S ₃ of, more than 30% of the maximum effective surface area S ₁ of the stirring wing, may enhance the over-vertical circulation flow, which may become a cause of uneven distribution of particles.
The total area S ₃ of the stirring aileron means the total area of the part related to the discharge of coating the coating liquid of a stirring ailerons are associated with the stirring wing, the surface area of the fill portion indicated by S ₃ in FIG. 6 It is.
Total area S ₃ of the stirring aileron can be determined by calculating the total area of the stirring aileron. That is, it can be calculated from (the width of the stirring auxiliary blade c × the height e of the stirring auxiliary blade) × the number of the stirring auxiliary blades in FIG. The height e is constant even when the auxiliary stirring blade is inclined.

The inclination angle θ2 of the stirring auxiliary blade is preferably 90 ° or less, and more preferably 60 ° to 85 °. When the inclination angle θ2 of the auxiliary stirring blade exceeds 90 °, the flow in the swirling direction formed by the main stirring blade and the flow of the vertical circulation flow are hindered, thereby reducing the stirring ability and causing sedimentation of particles. There is.
The inclination angle θ2 of the auxiliary stirring blade means the inclination angle of the auxiliary stirring blade with respect to the horizontal plane, similarly to the inclination angle θ1 of the main stirring blade, and is indicated by an angle θ2 in FIG.

<Baffle>
The stirring tank preferably has 2 to 6 baffles. Since the stirring tank has two or more baffles, the circulating flow in the rotating direction with low stirring ability is replaced with a circulating flow in the vertical direction effective for sedimentation of particles by colliding with the baffle. This greatly improves the stirring ability and has a great effect on particle sedimentation.
When the number of the baffles exceeds 6, the interval between the baffles becomes narrow, and a dead space in which the coating liquid for coating stays is generated. In the dead space, a staying phenomenon of the coating liquid for coating occurs, and no flow is formed against the sedimentation of the particles, resulting in variations in the concentration of the particles.
The length _{D 1} of the said baffle is preferably from 5% to 20% of the maximum inside diameter D of the stirring vessel, and more preferably 10% to 15%. The length D ₁ of the said baffle is less than 5% of the maximum inner diameter D of the agitating tank, there is the area of the baffle weakened the effect of replacing the smaller rotational flow in the vertical direction of the circulating flow. On the other hand, the length D ₁ of the said baffle is greater than 20% of the maximum inner diameter D of the stirring vessel, the area of the baffle is increased, it baffles rear hitting behind the rotational direction, dead space where the coating coating liquid is staying It may occur, and in the dead space, the particles may settle and cause a variation in the concentration of the particles.

  The baffle is markedly improved by being installed in the stirring tank in the vertical direction from the upper part of the stirring tank toward the lower part of the stirring tank. The baffle is installed as a baffle plate that obstructs the flow in the first place. For this reason, the installation at an angle or at an angle may cause a dead space and cause a variation in the concentration of particles.

<Coating solution for coating>
The coating liquid for coating includes at least a binder resin and particles, and includes a liquid medium and, if necessary, other components.

<< Binder resin >>
The binder resin is not particularly limited as long as it is generally used for carriers, and can be appropriately selected according to the purpose. For example, silicone resin, fluororesin, acrylic resin, acrylic resin and amino resin Reaction products, epoxy resins, polyurethane resins, fluororesin-modified silicone resins, acrylic-modified silicone resins, epoxy-modified silicone resins, urethane-modified silicone resins, and the like. These may be used individually by 1 type and may use 2 or more types together.

<< Particles >>
The particles are not particularly limited as long as they have electrical conductivity, and those having a small particle size that can be separated from the dispersing beads by filtration, that is, those having an average primary particle size of 5 nm to 500 nm are preferable. .
Examples of the particles include tin oxide, indium oxide doped tin oxide, conductively treated tin oxide, titanium oxide, zinc oxide, iron suboxide, titanium black, and carbon black. Needle-like powders (titanium oxide, zinc oxide, etc.) and flake-like powders (graphite, aluminum flakes, copper flakes, metal flakes such as nickel flakes, conductive mica, etc.) can be used. Further, a high resistance material such as hydrophobized silica or alumina powder can be used in combination. These may be used individually by 1 type and may use 2 or more types together.

<< Liquid medium >>
The liquid medium is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include petroleum solvents such as normal hexane and kerosene, halogenated hydrocarbon solvents, and aromatics such as benzene, toluene and xylene. Group solvents, ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone, alcohol solvents such as methanol, ethanol and isopropanol, ester solvents such as methyl acetate and ethyl acetate, ether solvents such as diethyl ether, tetrahydrofuran and dioxane Cyclic ethers such as ethylene glycol monomethyl ether (registered trademark = methyl cellosolve), glycol ethers such as ethylene glycol monoethyl ether (registered trademark = ethyl cellosolve), and nitrogen-containing organic solvents such as dimethylformamide. These may be used individually by 1 type and may use 2 or more types together.

The coating liquid for coating is obtained by dissolving or dispersing 0.02 parts by mass to 90 parts by mass of the binder resin in 100 parts by mass of the liquid medium, and the particles and other components as necessary. Containing.
There is no restriction | limiting in particular in the addition ratio of the said particle | grain with respect to the said binder resin, Although it can select suitably according to the objective, 5 / 100-600 / 100 is preferable by mass ratio.

<< Other ingredients >>
There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, For example, the crosslinking agent of a binder resin, a resistance regulator, etc. are mentioned.

<Method of feeding coating liquid for coating>
As a method for feeding the coating liquid for coating, it is preferable to feed by a pressurization method in which a gas is injected into a stirring tank to increase the internal pressure in order to make the concentration ratio of particles in the carrier coating film constant. As a method for feeding the coating liquid for coating, there are a gear pump, a tube pump system, and the like in the prior art. However, when feeding coating liquid containing particles, the gear pump wears the gear part, and the tube pump pulsates, the flow rate fluctuates during coating, making it difficult to form a uniform film. There's a problem. On the other hand, in the pressurization method, the above-described problem does not occur, and the liquid can always be sent to the coating apparatus in a state where the particle concentration is uniform.

<Coating equipment>
The coating apparatus is not particularly limited and may be appropriately selected depending on the purpose, but preferably has at least a spray nozzle and further includes other means as necessary.
There is no restriction | limiting in particular as said spray nozzle, According to the objective, it can select suitably, For example, the 2 fluid nozzle etc. which discharge a liquid and gas are mentioned.

<Other means>
There is no restriction | limiting in particular as said other means, According to the objective, it can select suitably, For example, a stirring means, a control means, etc. are mentioned.

Here, FIG. 1 is a schematic view showing an example of the entire apparatus for storing and feeding a coating liquid for coating a carrier according to the present invention. In FIG. 1, reference numeral 121 denotes a carrier coating liquid storage / feed device, and 122 denotes a coating device.
FIG. 2 is a schematic cross-sectional view of a stirring tank in a storage liquid feeding apparatus for a carrier coating coating liquid. 2 in 1 stirring vessel, 2 represents respectively baffles, stirrer rotation axis 3, the stirring wing 4, the stirring aileron 5, D is the maximum outer diameter of the stirring vessel, D ₁ baffle lengths.
FIG. 3 is a schematic view of a stirring main wing in a storage liquid feeding device for a carrier coating coating liquid. In FIG. 3, 3 is a stirring rotation shaft, 4 is a stirring main blade, 5 is a stirring auxiliary blade, and L is an auxiliary blade interval.
FIG. 7 is a schematic perspective view showing another example (curvature) of the stirring main wing, and FIG. 8 is a schematic perspective view showing another example (bending) of the stirring main wing.

  In the present invention, the particles present in the coating liquid for coating can be fed to the coating apparatus in a uniform state, and the concentration ratio of particles present in the carrier coating film can be made uniform. It becomes. As a result, it has a stable charge-imparting ability over a long period of time, excellent wear resistance (scraping / peeling), little change in carrier resistance, and no carrier adherence in the solid image area due to a decrease in resistance over time. In addition, it is possible to manufacture a carrier that does not cause toner contamination (background fogging) in the non-image area.

(Career)
The carrier of the present invention is produced by using the carrier liquid storage / feed device for coating of the carrier of the present invention.
Specifically, it is preferably manufactured by the carrier manufacturing method described below.

<Carrier manufacturing method>
The carrier production method used in the present invention is not particularly limited and can be appropriately selected according to the purpose.For example, a coating liquid preparation step for coating, a coating film coating step, a firing step, It is preferable to include a crushing step and a developer preparation step, and further include other steps as necessary.

-Coating liquid preparation process for coating-
The coating liquid preparation step for coating is a step in which a raw material is weighed at a desired ratio and subjected to a dispersion treatment using a disperser.
The disperser is not particularly limited as long as it is suitable for the raw material formulation, and may be any commonly used disperser, such as a homomixer, a blade rotating disperser (for example, Ebara Milder, Cavitron, etc.), Bead mill, etc.

-Coating film coating process-
The coating film coating step is a step of coating the surface of the core particles with the obtained coating liquid for coating the carrier using a coating apparatus.
The coating method is not particularly limited as long as it is a commonly used coating method, and can be appropriately selected according to the purpose. For example, a rolling fluidized bed using a spray, a core material is immersed in a dispersion liquid And a method of drying the solvent.

  The core particle is not particularly limited and can be appropriately selected from those known as two-component carriers for electrophotography. For example, iron, ferrite, magnetite, hematite, cobalt, iron-based, magnetite-based, Mn -Mg-Sr ferrite, Mn ferrite, Mn-Mg ferrite, Li ferrite, Mn-Zn ferrite, Cu-Zn ferrite, Ni-Zn ferrite, Ba ferrite and the like.

-Baking process-
The firing step is a step of firing with a firing device in order to dry or crosslink the coating film of the coated core material particles.
The baking apparatus is not particularly limited and may be any apparatus that is generally used. Examples thereof include an electric furnace, a rotary kiln, and a baking apparatus using high-frequency induction heating.

-Crushing process-
The said crushing process is a process of crushing in order to break up the particle | grains aggregated by baking.
The crushing device is not particularly limited as long as the particles can be crushed into one particle. Generally, a sieving device is often used, and examples thereof include a vibrating screen and an ultrasonic vibrating screen. Furthermore, when this sieving apparatus is used, not only the aggregation of particles but also the removal of coarse particles and the removal of foreign substances can be performed at the same time, which is very efficient.

-Developer preparation process-
The developer preparation step is a step of mixing the obtained carrier particles and toner particles at an appropriate mixing ratio to prepare an electrophotographic developer and a replenishment developer.
The resulting mixture is a developer, but here is only one example of its production method and is not limited to the contents described here.

(Developer)
The developer of the present invention comprises the carrier of the present invention and a toner.
The developer is preferably a replenishment developer containing 2 to 50 parts by mass of toner with respect to 1 part by mass of the carrier.

<Toner>
The toner includes not only a color toner generally used in a single color, but also a black toner in addition to yellow, magenta, cyan, red, green, blue and the like used for full color. Further, as the toner, a general toner can be used regardless of whether it is a monochrome toner, a color toner, or a full color toner. For example, conventionally kneaded and pulverized toners and various polymerized toners that have been used in recent years can be used.

  Furthermore, a toner containing a release agent, so-called oilless toner can also be used. In general, oilless toners contain a release agent, so that the release agent easily migrates to the surface of the carrier, so-called spent is likely to occur. Can maintain good quality. In particular, oilless full color toners are generally said to be easily spent because the binder resin is soft, but it can be said that the carrier used in the present invention is very suitable.

  The binder resin used for the toner is not particularly limited, and known resins can be used. For example, styrene such as polystyrene, poly-p-styrene, polyvinyltoluene and the like, and a substituted homopolymer, styrene-p- Chlorstyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-methacrylic acid copolymer, styrene- Methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethacrylate methyl copolymer, styrene-acrylonitrile copolymer, styrene- Vinyl methyl ether copolymer, styrene-vinyl methyl ketone copolymer, Styrene copolymers such as lene-butadiene copolymer, styrene-isopropyl copolymer, styrene-maleic acid ester copolymer, polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polyester, Examples include polyurethane, epoxy resin, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or aromatic hydrocarbon resin, and aromatic petroleum resin.

  Furthermore, there is no restriction | limiting in particular as binder resin for pressure fixing, A well-known thing can be mixed and used. For example, polyolefin such as low molecular weight polyethylene and low molecular weight polypropylene, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, styrene-methacrylic acid copolymer, ethylene-methacrylic acid ester copolymer, ethylene-chlorinated Vinyl copolymer, ethylene-vinyl acetate copolymer, olefin copolymer such as ionomer resin, epoxy resin, polyester resin, styrene-butadiene copolymer, polyvinylpyrrolidone, methyl vinyl ether-maleic anhydride, maleic acid modified phenol resin And phenol-modified terpene resins. These may be used individually by 1 type and may use 2 or more types together.

  In addition, the toner used in the present invention may contain a fixing aid in addition to the binder resin, the colorant, and the charge control agent. Accordingly, it can be used in a fixing system in which toner fixing prevention oil is not applied to the fixing roll, so-called oilless system. Known fixing aids can be used. For example, polyolefins such as polyethylene and polypropylene, fatty acid metal salts, fatty acid esters, paraffin waxes, amide waxes, polyhydric alcohol waxes, silicone varnishes, carnauba waxes and ester waxes can be used, but are not limited thereto.

  The colorant used in the toner such as the color toner is not particularly limited, and known pigments and dyes that can obtain toners of yellow, magenta, cyan, and black colors can be used. These may be used individually by 1 type and may use 2 or more types together.

  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, Tartrazine Lake, Etc.

  Examples of the orange pigment include molybdenum orange, permanent orange GTR, pyrazolone orange, vulcan orange, indanthrene brilliant orange RK, benzidine orange G, indanthrene brilliant orange GK, and the like.

  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, and the like. Is mentioned.

Examples of purple pigments include Fast Violet B and Methyl Violet Lake.
Examples of the blue pigment include cobalt blue, alkali blue, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partial chlorinated product, first sky blue, and indanthrene blue BC.
Examples of the green pigment include chrome green, chromium oxide, pigment green B, malachite green lake, and the like.
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 the charge control agent include nigrosine, an azine dye containing an alkyl group having 2 to 16 carbon atoms (see Japanese Patent Publication No. 42-1627), a basic dye (for example, CI Basic Yellow 2 (C.I.). I.41000), C.I.Basic Yellow 3, C.I.Basic Red 1 (C.I. 45160), C.I.Basic Red 9 (C.I. 42500), C.I.Basic Violet 1 ( C.I. 42535), C.I.Basic Violet 3 (C.I.42555), C.I.Basic Violet 10 (C.I.45170), C.I.Basic Violet 14 (C.I. 42510) ), C.I.Basic Blue 1 (C.I.42025), C.I.Basic Blue 3 (C CI Basic Blue 5 (C.I. 42140), C.I. Basic Blue 7 (C.I. 42595), C.I.Basic Blue 9 (C.I. 522015), C.I.Basic Blue 24 (C.I.52030), C.I.Basic Blue 25 (C.I.52025), C.I.Basic Blue 26 (C.I.44045), C.I.Basic Green 1 (CI 42040), CI Basic Green 4 (CI 42000), or lake pigments of these basic dyes, CI Solvent Black 8 (CI 26150), benzoyl Quaternary ammonium salts such as methyl hexadecyl ammonium chloride and decyl trimethyl chloride, or Is a dialkyltin compound such as dibutyl or dioctyl, a dialkyltin borate compound, a guanidine derivative, a vinyl polymer containing an amino group, a polyamine resin such as a condensation polymer containing an amino group, JP-B-41-20153, JP-B No. 43-27596, JP-B 44-6397, JP-B 45-26478, metal complexes of monoazo dyes, JP-B 55-42752, JP-B 59-7385 Metal complexes of salicylic acid, dialkylsalicylic acid, naphthoic acid, dicarboxylic acid such as Zn, Al, Co, Cr, Fe, etc., sulfonated copper phthalocyanine pigments, organic boron salts, fluorine-containing quaternary ammonium salts, calixarene series Compound etc. are mentioned. In addition, for color toners other than black, naturally, the use of a charge control agent that impairs the target color should be avoided, and a white metal salt of a salicylic acid derivative is preferably used.

  As the external additive, transferability and durability are further improved by externally adding inorganic fine particles such as silica, titanium oxide, alumina, silicon carbide, silicon nitride, boron nitride and resin fine particles to the base toner particles. . This effect can be obtained by covering the wax that lowers transferability and durability with these external additives and reducing the contact area due to the toner surface being covered with fine particles. The surface of these inorganic fine particles is preferably subjected to a hydrophobic treatment, and metal oxide fine particles such as silica and titanium oxide subjected to the hydrophobic treatment are preferably used. As the resin fine particles, polymethyl methacrylate or polystyrene fine particles having an average particle size of about 0.05 μm to 1 μm obtained by a soap-free emulsion polymerization method are suitably used.

In addition, the hydrophobized silica and the hydrophobized titanium oxide are used in combination, and the external addition amount of the hydrophobized titanium oxide is larger than the hydrophobized silica external charge amount, thereby charging against humidity. The toner can also be excellent in stability. In combination with the above inorganic fine particles, silica, average particle size of the specific surface area of ^{20m 2} / ^g~50m 2 / g is conventionally used as the fine resin particles is 1/100 to 1/8 of the average particle size of the toner The durability can be improved by externally adding an external additive having a particle size larger than that of the external additive to the toner.

  In the process where the toner is mixed and stirred with a carrier in the developing device, charged, and subjected to development, the metal oxide fine particles added externally to the toner tend to be embedded in the base toner particles. This is because it is possible to prevent the metal oxide fine particles from being embedded by externally adding an external additive having a particle size larger than the fine particles to the toner.

  When the inorganic fine particles and the resin fine particles are contained (internally added) in the toner, the effect is reduced as compared with the case where the fine particles are added externally, but the effect of improving transferability and durability can be obtained and the pulverizing property of the toner can be improved. it can. In addition, since external addition and internal addition can be used together to suppress embedding of externally added fine particles, excellent transferability can be stably obtained and durability can be improved.

  Examples of the hydrophobizing agent include dimethyldichlorosilane, trimethylchlorosilane, methyltrichlorosilane, allyldimethyldichlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, and α-chloroethyl. Trichlorosilane, p-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, chloromethyltrichlorosilane, p-chlorophenyltrichlorosilane, 3-chloropropyltrichlorosilane, 3-chloropropyltrimethoxysilane, vinyltriethoxysilane, vinylmethoxy Silane, vinyl-tris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, divinyldichlorosilane, di Tylvinylchlorosilane, octyl-trichlorosilane, decyl-trichlorosilane, nonyl-trichlorosilane, (4-t-propylphenyl) -trichlorosilane, (4-t-butylphenyl) -trichlorosilane, diventyl-dichlorosilane, dihexyl- Dichlorosilane, dioctyl-dichlorosilane, dinonyl-dichlorosilane, didecyl-dichlorosilane, didodecyl-dichlorosilane, dihexadecyl-dichlorosilane, (4-t-butylphenyl) -octyl-dichlorosilane, dioctyl-dichlorosilane, didecenyl-dichlorosilane, dinonenyl-2-dichlorosilane -Ethylhexyl-dichlorosilane, di-3,3-dimethylbenchyl-dichlorosilane, trihexyl-chlorosilane, trioctyl-chloro Silane, tridecyl-chlorosilane, dioctyl-methyl-chlorosilane, octyl-dimethyl-chlorosilane, (4-t-propylphenyl) -diethyl-chlorosilane, octyltrimethoxysilane, hexamethyldisilazane, hexaethyldisilazane, diethyltetramethyldisilane Silazane, hexaphenyldisilazane, hexatolyldisilazane and the like can be mentioned. Other titanate coupling agents and aluminum coupling agents can also be used. In addition, as an external additive for the purpose of improving cleaning properties, a lubricant such as a fatty acid metal salt or a fine particle of polyvinylidene fluoride can be used in combination.

<< Toner Production Method >>
There is no restriction | limiting in particular as manufacture of the said toner, Conventionally well-known methods, such as a grinding method and a polymerization method, are applicable. For example, in the case of the pulverization method, as a device for kneading the toner, a batch type two roll, a Banbury mixer or a continuous type twin screw extruder, for example, KTK type twin screw extruder manufactured by Kobe Steel, manufactured by Toshiba Machine Co., Ltd. TEM type twin screw extruder, KCK twin screw extruder, Ikegai Iron Works PCM type twin screw extruder, Kurimoto Iron Works KEX type twin screw extruder, continuous single screw kneader, for example Buss Co-kneader etc. are preferably used. The melt-kneaded product obtained as described above is cooled and then pulverized. For pulverization, for example, coarsely pulverized using a hammer mill, a funnel plex or the like, and further, a fine pulverizer using a jet stream or mechanical pulverization A machine can be used. The pulverization is preferably performed so that the average particle diameter is 3 μm to 15 μm. Further, the pulverized product is preferably adjusted to a particle size of 5 μm to 20 μm by a wind classifier or the like.

  Next, the external additive is externally added to the base toner. The base toner and the external additive are mixed and stirred using a mixer, and the external additive is crushed and coated on the toner surface. At this time, it is important in terms of durability that external additives such as inorganic fine particles and resin fine particles are uniformly and firmly attached to the base toner.

(Process cartridge)
The process cartridge of the present invention has at least a latent electrostatic image bearing member and developing means for developing a latent electrostatic image on the latent electrostatic image bearing member with a developer to form a visible image. Depending on the situation, other means are provided.
The developer is the developer of the present invention.
The developing means includes at least a developer container that contains the toner or the developer, and a developer carrier that carries and transports the toner or developer contained in the developer container. Further, a layer thickness regulating member for regulating the thickness of the toner layer to be carried may be provided.
The process cartridge can be detachably provided in various electrophotographic image forming apparatuses, and is preferably provided detachably in the image forming apparatus of the present invention described later.

Here, as shown in FIG. 9, for example, the process cartridge includes an electrostatic latent image carrier 101, and includes a charging unit 102, a developing unit 104, a transfer unit 108, and a cleaning unit 107, and further, if necessary. And other means. In FIG. 9, reference numeral 103 denotes exposure by exposure means, and 105 denotes a recording medium.
Next, the image forming process using the process cartridge shown in FIG. 9 will be described. The electrostatic latent image carrier 101 is charged by the charging unit 102 while being rotated in the direction of the arrow, and exposure 103 by the exposure unit (not shown). An electrostatic latent image corresponding to the exposure image is formed on the surface. The electrostatic latent image is developed by the developing unit 104, and the obtained visible image is transferred to the recording medium 105 by the transfer unit 108 and printed out. Next, the surface of the latent electrostatic image bearing member after the image transfer is cleaned by the cleaning unit 107, further neutralized by a neutralizing unit (not shown), and the above operation is repeated again.

<Image Forming Apparatus and Image Forming Method>
Here, an embodiment in which the image forming method used in the present invention is carried out by the image forming apparatus used in the present invention will be described with reference to the drawings.
The image forming apparatus 100 in the example shown in FIG. 10 includes a photosensitive drum 10 (hereinafter, also referred to as “photosensitive member 10”) as an electrostatic latent image carrier, a roller-shaped charging unit 20, and an exposure unit 30. A developing unit 40, an intermediate transfer member 50, a cleaning unit 60 having a cleaning blade, and a static elimination lamp as a static elimination unit 70.

  The intermediate transfer member 50 is an endless belt, and is designed to be movable in the direction of an arrow by three rollers 51 that are arranged inside and stretched. Part of the three rollers 51 also functions as a transfer bias roller that can apply a predetermined transfer bias (primary transfer bias) to the intermediate transfer member 50. A cleaning unit 90 having a cleaning blade is disposed in the vicinity of the intermediate transfer body 50, and a developed image (image-forming particle image) is transferred (secondary transfer) onto a transfer sheet 95 as a final transfer material. A transfer roller serving as a transfer unit 80 to which a transfer bias for applying the transfer bias can be applied. Around the intermediate transfer member 50, a corona charger 58 for applying a charge to the image forming particle image on the intermediate transfer member 50 is arranged in the rotational direction of the intermediate transfer member 50 with the photosensitive member 10 and the intermediate transfer member 50. And the contact portion between the intermediate transfer member 50 and the transfer paper 95.

  The developing means 40 includes a developing belt 41 as a developer carrying member, a black developing means (unit) 45K, a yellow developing means (unit) 45Y, a magenta developing means (unit) 45M, and cyan provided around the developing belt 41. And developing means (unit) 45C. The black developing means 45K includes a developer accommodating portion 42K, a developer supply roller 43K, and a developing roller 44K, and the yellow developing means 45Y includes a developer accommodating portion 42Y, a developer supplying roller 43Y, and a developing roller 44Y. The magenta developing unit 45M includes a developer accommodating portion 42M, a developer supplying roller 43M, and a developing roller 44M, and the cyan developing unit 45C includes a developer accommodating portion 42C and a developer supplying roller 43C. And a developing roller 44C. 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 photoconductor 10.

  In the image forming apparatus 100 shown in FIG. 10, for example, the charging unit 20 uniformly charges the photosensitive drum 10. The exposure means 30 exposes the image on the photosensitive drum 10 imagewise to form an electrostatic latent image. The electrostatic latent image formed on the photosensitive drum 10 is developed by supplying image forming particles from the developing unit 40 to form a visible image (image forming particle image). The visible image (image-forming particle image) is transferred (primary transfer) onto the intermediate transfer body 50 by the voltage applied from the roller 51, and further transferred (secondary transfer) onto the transfer paper 95. As a result, a transfer image is formed on the transfer paper 95. The remaining image forming particles on the photoconductor 10 are removed by the cleaning unit 60, and the charge on the photoconductor 10 is once removed by the charge eliminating unit (static charge lamp) 70.

  Next, the image forming apparatus 100 shown in FIG. 11 does not include the developing belt 41 in the image forming apparatus 100 shown in FIG. 10, and the black developing means (developing unit) 45K and the yellow developing means ( 7 has the same configuration as that of the image forming apparatus 100 shown in FIG. 7 except that a developing unit 45Y, a magenta developing unit (developing unit) 45M, and a cyan developing unit (developing unit) 45C are directly opposed to each other. And the same effect is shown. In FIG. 11, the same components as those in FIG. 10 are denoted by the same reference numerals.

A tandem image forming apparatus 120 shown in FIG. 12 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 apparatus 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. 12. An intermediate transfer body cleaning device 17 for removing residual image forming particles 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 is a tandem type in which four image forming units 18 of yellow, cyan, magenta, and black are arranged to face each other along the conveyance direction. Developing means 120 is arranged. An exposure unit 21 is disposed in the vicinity of the tandem developing unit 120. A secondary transfer unit 22 is disposed on the side of the intermediate transfer member 50 opposite to the side on which the tandem developing unit 120 is disposed. In the secondary transfer unit 22, a secondary transfer belt 24, which is an endless belt, is stretched around a pair of rollers 23, and the transfer paper conveyed on the secondary transfer belt 24 and the intermediate transfer member 50 are in contact with each other. Is possible. A fixing unit 25 is disposed in the vicinity of the secondary transfer unit 22. The fixing unit 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, a sheet reversing device 28 for reversing the transfer paper for image formation on both sides of the transfer paper is disposed in the vicinity of the secondary transfer unit 22 and the fixing unit 25. Yes.

  Next, formation of a full-color image (color copy) using the tandem developing unit 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 a document is set on the contact glass 32 of the scanner 300. 400 is closed.

  When a start switch (not shown) is pressed, when the document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the contact glass 32. Immediately after that, the scanner 300 is driven, and 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 received by the reading sensor 36 through the imaging lens 35 to be color. An original (color image) is read and used 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 image forming means in the tandem developing means 120. ) And image forming particle images of black, yellow, magenta and cyan are formed in each image forming means. That is, each image forming means 18 (black image forming means, yellow image forming means, magenta image forming means, and cyan image forming means) in the tandem developing means 120 is a partially enlarged schematic view of FIG. As shown in FIG. 13, the photosensitive member 10 (the black photosensitive member 10K, the yellow photosensitive member 10Y, the magenta photosensitive member 10M, and the cyan photosensitive member 10C) and charging that uniformly charges the photosensitive member. Based on the means 59 and each color image information, the photoconductor is exposed like an image corresponding to each color image (L in FIG. 13), and an electrostatic latent image corresponding to each color image is formed on the photoconductor. An exposure unit and the electrostatic latent image are developed using each color developer (black developer, yellow developer, magenta developer, and cyan developer) of the present invention, and a toner image formed by each color developer is developed. Developing means 61, a transfer charger 62 for transferring the developed toner image onto the intermediate transfer body 50, a photosensitive member cleaning means 63, and a static eliminator 64. Each monochrome image (black image, yellow image, magenta image, and cyan image) can be formed based on the image information. The black image, the yellow image, the magenta image, and the cyan image formed in this way are respectively transferred to the black photoconductor 10K on the intermediate transfer member 50 that is rotated by the support rollers 14, 15, and 16 in FIG. The black image formed above, the yellow image formed on the yellow photoconductor 10Y, the magenta image formed on the magenta photoconductor 10M, and the cyan image formed on the cyan photoconductor 10C are 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 to feed out a sheet (recording paper) from one of the paper feed cassettes 144 provided in multiple stages in the paper bank 143. Each sheet is separated and sent to the paper feed path 146, transported by the transport roller 147, guided to the paper feed path 148 in the copying machine main body 150, and abutted against the registration roller 49 and stopped. Alternatively, the sheet feed roller 142 is rotated to feed out sheets (recording paper) on the manual feed tray 54, separated one by one by the separation roller 52, put into the manual feed path 53, and abutted against the registration roller 49 and stopped. . 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) obtained by synthesizing the respective toners on the intermediate transfer member 50, and a sheet (between the intermediate transfer member 50 and the secondary transfer unit 22). Recording paper) is transferred, and the combined color image (color transfer image) is transferred (secondary transfer) onto the sheet (recording paper) by the secondary transfer means 22, whereby the color on the sheet (recording paper) is transferred. An image is transferred and formed. The residual toner on the intermediate transfer member 50 after image transfer is 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 means 22 and sent to the fixing means 25, where the combined color image (color) is generated by heat and pressure. (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 reversed by the sheet reversing device 28 and transferred again. After being guided to the position and recording an image on the back surface, the image is discharged by the discharge roller 56 and stacked on the discharge tray 57.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

Example 1
<Creation of carrier>
The following composition was dispersed with a homomixer for 10 minutes to prepare a coating solution for coating the carrier.
・ Acrylic resin solution (solid content: 50 mass%): 85 mass parts ・ Guanamine solution (solid content: 70 mass%): 26 mass parts ・ Acid catalyst (solid content: 40 mass%) ·· 1 part by mass · Silicone resin solution (solid content: 20% by mass) ... 290 parts by mass · Aminosilane (solid content: 100% by mass) · 2 parts by mass · Conductive treated titanium oxide particles (surface: ITO treatment, primary particle diameter: 50 nm, volume resistivity: 1.0 × 10 ² Ω · cm) 185 parts by mass Toluene 500 parts by mass

  The obtained coating liquid for coating the carrier was put into a stirring tank having a hemispherical shape (horizontal cross section is circular) and having a baffle as shown below. Stirring was performed using a storage liquid feeding device.

<Stirring tank>
・ Shape: hemisphere (horizontal section is circular)
・ Maximum inner diameter D: 40 cm
・ Maximum area S ₀ of horizontal section of stirring tank: 1,257 cm ² (circle area with a radius of 20 cm (20 × 20 × 3.14 = 1,257 cm ² ))

<Baffle>
・ Shape: Rectangular (thickness 10mm)
Baffle number: four baffle length _D 1: 4 cm (10% of the maximum inside diameter D of the stirring vessel)

<Stirring wing>
・ Rotation speed: 150rpm
・ Shape: Pitched airfoil (4 blades)
Maximum effective surface area S ₁ : 188.6 cm ² (15% of the maximum area S ₀ (1,257 cm ² ) of the horizontal section of the stirring tank)
・ Outer diameter d: 20 cm
・ Height b: 4.7cm
・ Inclination angle θ1: 45 °
-Maximum area S ₂ of the height component: 20 × 4.7 = 94 cm ² (50% of the maximum effective surface area S ₁ (188.6 cm ² ) of the stirring main wing)
・ Wing shape: Flat plate ・ Liquid feeding method: Pressurized liquid feeding method

  Next, a sintered ferrite powder [DFC-400M (Mn ferrite, manufactured by DOWA IP Creation Co., Ltd.)] having an average particle diameter of 35 μm is used as the core particle, and the coating liquid for coating is stored from the above-described coating liquid storage and feeding apparatus. 1 was fed to the spray nozzle, and coated on the surface of the core material particles at a coater temperature of 40 ° C. and dried by a Spira coater (Okada Seiko Co., Ltd.) so that the thickness was 0.2 μm. The obtained carrier was baked by standing in an electric furnace at 150 ° C. for 1 hour. After cooling, the ferrite powder bulk was crushed using a sieve having an aperture of 63 μm to obtain [Carrier 1].

<Production of toner>
Binder resin: Polyester resin: 100 parts by mass Release agent: Carnauba wax: 5 parts by mass Charge control agent: E-84 (manufactured by Orient Chemical Co., Ltd.): 1 part by mass Colorant: C.I. I. Pigment Yellow 180 ... 8 parts by mass Among the above materials, the colorant, the binder resin, and pure water were mixed at 1: 1: 0.5 (mass ratio) and kneaded by two rolls. Kneading was performed at 70 ° C., and then the roll temperature was raised to 120 ° C. to evaporate water and prepare a master batch in advance. Using the obtained master batch, weigh the materials so that they are the same as the above recipe, mix with a Henschel mixer, melt knead for 40 minutes at 120 ° C with two rolls, cool, and then coarsely pulverize with a hammer mill Thereafter, fine powder obtained by fine pulverization with an air jet pulverizer was classified to prepare toner base particles having a weight average particle diameter of 5 μm.
Further, yellow toner is obtained by adding 1 part by mass of silica whose surface is hydrophobized and 1 part by mass of titanium oxide whose surface is hydrophobized to 100 parts by mass of the toner base particles, and mixing with a Henschel mixer. [Toner 1] was obtained.
7 parts by mass of the obtained [Toner 1] and 93 parts by mass of [Carrier 1] were mixed and stirred to prepare a developer having a toner concentration of 7% by mass.

(Example 2)
In Example 1, except that the hemispherical stirring tank was changed to a cylindrical stirring tank having a maximum inner diameter D of 40 cm, it was converted into a carrier to obtain [Carrier 2].
A developer was produced from the obtained [Carrier 2] and [Toner 1] in the same manner as in Example 1.

Example 3
In Example 1, except that the stirring main wing was changed to the stirring main wing shown below, a carrier was formed in the same manner as in Example 1 to obtain [Carrier 3].
A developer was produced from the obtained [Carrier 3] and [Toner 1] in the same manner as in Example 1.
<Stirring wing>
・ Rotation speed: 150rpm
・ Shape: Pitched airfoil (4 blades)
Maximum effective surface area S ₁ : 188.6 cm ² (15% of the maximum area S ₀ (1,257 cm ² ) of the horizontal section of the stirring tank)
・ Outer diameter d: 20 cm
・ Height b: 2.4 cm
・ Inclination angle θ1: 22 °
-Maximum area S ₂ of the height component: 20 × 2.4 = 48 cm ² (25% of the maximum effective surface area S ₁ (188.6 cm ² ) of the stirring main wing)
・ Wing shape: Flat plate ・ Liquid feeding method: Pressurized liquid feeding method

Example 4
In Example 1, except that the stirring main wing was changed to the stirring main wing shown below, a carrier was formed in the same manner as in Example 1 to obtain [Carrier 4].
A developer was produced from the obtained [Carrier 4] and [Toner 1] in the same manner as in Example 1.
<Stirring wing>
・ Rotation speed: 150rpm
・ Shape: Pitched airfoil (4 blades)
Maximum effective surface area S ₁ : 188.6 cm ² (15% of the maximum area S ₀ (1,257 cm ² ) of the horizontal section of the stirring tank)
・ Outer diameter d: 20 cm
-Height b: 6.6 cm
・ Inclination angle θ1: 63 °
-Maximum area S ₂ of the height component: 20 × 6.6 = 132 cm ² (70% of the maximum effective surface area S ₁ (188.6 cm ² ) of the stirring main wing)
・ Wing shape: Flat plate ・ Liquid feeding method: Pressurized liquid feeding method

(Example 5)
In Example 1, except that the stirring main wing was changed to the stirring main wing shown below, a carrier was formed in the same manner as in Example 1 to obtain [Carrier 5].
A developer was produced from the obtained [Carrier 5] and [Toner 1] in the same manner as in Example 1.
<Stirring wing>
・ Rotation speed: 150rpm
・ Shape: Pitched airfoil (4 blades)
Maximum effective surface area S ₁ : 37.7 cm ² (3% of the maximum area S ₀ (1,257 cm ² ) of the horizontal section of the stirring tank)
・ Outer diameter d: 20 cm
・ Height b: 0.94cm
・ Inclination angle θ1: 45 °
-Maximum area S ₂ of the height component: 20 × 0.94 = 18.8 cm ² (50% of the maximum effective surface area S ₁ (37.7 cm ² ) of the stirring main wing)
・ Wing shape: Flat plate ・ Liquid feeding method: Pressurized liquid feeding method

(Example 6)
In Example 1, except that the stirring main wing was changed to the stirring main wing shown below, a carrier was formed in the same manner as in Example 1 to obtain [Carrier 6].
A developer was prepared from the obtained [Carrier 6] and [Toner 1] in the same manner as in Example 1.
<Stirring wing>
・ Rotation speed: 150rpm
・ Shape: Pitched airfoil (4 blades)
Maximum effective surface area S ₁ : 62.9 cm ² (5% of the maximum area S ₀ (1,257 cm ² ) of the horizontal section of the stirring tank)
・ Outer diameter d: 20 cm
・ Height b: 1.6cm
・ Inclination angle θ1: 45 °
-Maximum area S ₂ of the height component: 20 × 1.6 = 32 cm ² (50% of the maximum effective surface area S ₁ (62.9 cm ² ) of the stirring main wing)
・ Wing shape: Flat plate ・ Liquid feeding method: Pressurized liquid feeding method

(Example 7)
In Example 1, except that the stirring main wing was changed to the stirring main wing shown below, it was converted into a carrier in the same manner as in Example 1 to obtain [Carrier 7].
A developer was prepared from the obtained [Carrier 7] and [Toner 1] in the same manner as in Example 1.
<Stirring wing>
・ Rotation speed: 150rpm
・ Shape: Pitched airfoil (4 blades)
Maximum effective surface area S ₁ : 251.4 cm ² (20% of the maximum area S ₀ (1,257 cm ² ) of the horizontal section of the stirring tank)
・ Outer diameter d: 20 cm
・ Height b: 6.3cm
・ Inclination angle θ1: 45 °
-Maximum area S ₂ of the height component: 20 × 6.3 = 126 cm ² (50% of the maximum effective surface area S ₁ (251.4 cm ² ) of the stirring main wing)
・ Wing shape: Flat plate ・ Liquid feeding method: Pressurized liquid feeding method

(Example 8)
In Example 1, except that the stirring main wing was changed to the stirring main wing shown below, a carrier was formed in the same manner as in Example 1 to obtain [Carrier 8].
A developer was prepared from the obtained [Carrier 8] and [Toner 1] in the same manner as in Example 1.
<Stirring wing>
・ Rotation speed: 150rpm
・ Shape: Pitched airfoil (4 blades)
Maximum effective surface area S ₁ : 276.5 cm ² (22% of the maximum area S ₀ (1,257 cm ² ) of the horizontal section of the stirring tank)
・ Outer diameter d: 20 cm
・ Height b: 6.9cm
・ Inclination angle θ1: 45 °
-Maximum area S ₂ of the height component: 20 × 6.9 = 138 cm ² (50% of the maximum effective surface area S ₁ (276.5 cm ² ) of the stirring main wing)
・ Wing shape: Flat plate ・ Liquid feeding method: Pressurized liquid feeding method

Example 9
In Example 1, except that the stirring main wing was changed to the stirring main wing shown below, it was converted into a carrier in the same manner as in Example 1 to obtain [Carrier 9].
A developer was produced from the obtained [Carrier 9] and [Toner 1] in the same manner as in Example 1.
<Stirring wing>
・ Rotation speed: 150rpm
・ Shape: Pitched airfoil (4 blades)
Maximum effective surface area S ₁ : 188.6 cm ² (15% of the maximum area S ₀ (1,257 cm ² ) of the horizontal section of the stirring tank)
・ Outer diameter d: 20 cm
・ Height b: 4.7cm
・ Inclination angle θ1: 45 °
-Maximum area S ₂ of the height component: 20 × 4.7 = 94 cm ² (50% of the maximum effective surface area S ₁ (188.6 cm ² ) of the stirring main wing)
-Blade shape: curved-Liquid feeding method: Pressurized liquid feeding method

(Example 10)
In Example 1, except that the following two auxiliary stirring blades were installed on top of the four stirring main blades, a carrier was formed in the same manner as in Example 1 to obtain [Carrier 10].
A developer was produced from the obtained [Carrier 10] and [Toner 1] in the same manner as in Example 1.
<Agitating auxiliary blade>
-Total area S _{3 of the} auxiliary stirring blade: 28.29 cm ² (15% of the maximum effective surface area S ₁ (188.6 cm ² ) of the main stirring blade)
-Stirring auxiliary blade inclination angle θ2: 80 °

(Example 11)
In Example 10, except that the stirring auxiliary blade was changed to the stirring auxiliary blade shown below, it was converted into a carrier in the same manner as in Example 10 to obtain [Carrier 11].
A developer was produced from the obtained [Carrier 11] and [Toner 1] in the same manner as in Example 1.
<Agitating auxiliary blade>
-Total area S _{3 of the} auxiliary stirring blade: 28.29 cm ² (15% of the maximum effective surface area S ₁ (188.6 cm ² ) of the main stirring blade)
-Stirring auxiliary blade tilt angle θ2: 0 °

(Example 12)
In Example 10, except that the stirring auxiliary blade was changed to the stirring auxiliary blade shown below, it was converted into a carrier in the same manner as in Example 10 to obtain [Carrier 12].
A developer was prepared from the obtained [Carrier 12] and [Toner 1] in the same manner as in Example 1.
<Agitating auxiliary blade>
-Total area S _{3 of the} auxiliary stirring blade: 28.29 cm ² (15% of the maximum effective surface area S ₁ (188.6 cm ² ) of the main stirring blade)
-Stirring auxiliary blade inclination angle θ2: 90 °

(Example 13)
In Example 10, a carrier was obtained in the same manner as in Example 10 except that the auxiliary stirring blade was changed to the following auxiliary stirring blade to obtain [Carrier 13].
A developer was produced from the obtained [Carrier 13] and [Toner 1] in the same manner as in Example 1.
<Agitating auxiliary blade>
-Total area S _{3 of the} auxiliary stirring blade: 28.29 cm ² (15% of the maximum effective surface area S ₁ (188.6 cm ² ) of the main stirring blade)
-Stirring auxiliary blade inclination angle θ2: 95 °

(Example 14)
In Example 10, except that the auxiliary stirring blade was changed to the auxiliary stirring blade shown below, a carrier was formed in the same manner as in Example 10 to obtain [Carrier 14].
A developer was prepared from the obtained [Carrier 14] and [Toner 1] in the same manner as in Example 1.
<Agitating auxiliary blade>
-Total area S _{3 of the} auxiliary stirring blade: 56.58 cm ² (30% of the maximum effective surface area S ₁ (188.6 cm ² ) of the main stirring blade)
-Stirring auxiliary blade inclination angle θ2: 80 °

(Example 15)
In Example 10, except that the auxiliary stirring blade was changed to the auxiliary stirring blade shown below, a carrier was formed in the same manner as in Example 10 to obtain [Carrier 15].
A developer was produced from the obtained [Carrier 15] and [Toner 1] in the same manner as in Example 1.
<Agitating auxiliary blade>
-Total area S _{3 of the} auxiliary stirring blade: 66.01 cm ² (35% of the maximum effective surface area S ₁ (188.6 cm ² ) of the main stirring blade)
-Stirring auxiliary blade inclination angle θ2: 80 °

(Example 16)
In Example 1, except that the baffle was changed to the baffle shown below, a carrier was formed in the same manner as in Example 1 to obtain [Carrier 16].
A developer was produced from the obtained [Carrier 16] and [Toner 1] in the same manner as in Example 1.
<Baffle>
・ Shape: Rectangular (thickness 10mm)
-Number of baffles: 4-Baffle length D ₁ : 1.2 cm (3% of maximum inner diameter D (40 cm) of stirring tank)

(Example 17)
In Example 1, except that the baffle was changed to the baffle shown below, a carrier was formed in the same manner as in Example 1 to obtain [Carrier 17].
A developer was produced from the obtained [Carrier 17] and [Toner 1] in the same manner as in Example 1.
<Baffle>
・ Shape: Rectangular (thickness 10mm)
-Number of baffles: 4-Baffle length D ₁ : 2 cm (5% of the maximum inner diameter D (40 cm) of the stirring tank)

(Example 18)
In Example 1, except that the baffle was changed to the baffle shown below, a carrier was formed in the same manner as in Example 1 to obtain [Carrier 18].
A developer was produced from the obtained [Carrier 18] and [Toner 1] in the same manner as in Example 1.
<Baffle>
・ Shape: Rectangular (thickness 10mm)
-Number of baffles: 4-Baffle length D ₁ : 8 cm (20% of the maximum inner diameter D (40 cm) of the stirring tank)

(Example 19)
In Example 1, except that the baffle was changed to the baffle shown below, a carrier was formed in the same manner as in Example 1 to obtain [Carrier 19].
A developer was produced from the obtained [Carrier 19] and [Toner 1] in the same manner as in Example 1.
<Baffle>
・ Shape: Rectangular (thickness 10mm)
-Number of baffles: 4-Baffle length D ₁ : 8.8 cm (22% of the maximum inner diameter D (40 cm) of the stirring tank)

(Example 20)
In Example 1, except that the baffle was changed to the baffle shown below, a carrier was formed in the same manner as in Example 1 to obtain [Carrier 20].
A developer was produced from the obtained [Carrier 20] and [Toner 1] in the same manner as in Example 1.
<Baffle>
・ Shape: Rectangular (thickness 10mm)
-Number of baffles: 7-Baffle length D ₁ : 4 cm (10% of the maximum inner diameter D (40 cm) of the stirring tank)

(Example 21)
In Example 1, except that the feeding of the coating liquid for coating the carrier was changed to a tube pump, it was converted into a carrier in the same manner as in Example 1 to obtain [Carrier 21].
A developer was produced from the obtained [Carrier 21] and [Toner 1] in the same manner as in Example 1.

(Example 22)
In Example 1, except that the shape of the stirring main blade was changed to Example 9 and the auxiliary stirring blade was changed to Example 10, it was converted into a carrier in the same manner as in Example 1 to obtain [Carrier 22].
A developer was produced from the obtained [Carrier 22] and [Toner 1] in the same manner as in Example 1.

(Comparative Example 1)
In Example 1, except that it changed from the hemispherical stirring tank to the rectangular parallelepiped stirring tank, it was converted into a carrier in the same manner as in Example 1 to obtain [Carrier 26].
A developer was produced from the obtained [Carrier 26] and [Toner 1] in the same manner as in Example 1.

(Comparative Example 2)
In Example 1, except that no baffle was provided, a carrier was formed in the same manner as in Example 1 to obtain [Carrier 27].
A developer was produced from the obtained [Carrier 27] and [Toner 1] in the same manner as in Example 1.

(Comparative Example 3)
In Example 1, except that the stirring main wing was changed to the following stirring main wing, it was converted into a carrier in the same manner as in Example 1 to obtain [Carrier 28].
A developer was produced from the obtained [Carrier 28] and [Toner 1] in the same manner as in Example 1.
<Stirring wing>
・ Rotation speed: 150rpm
・ Shape: Pitched airfoil (4 blades)
Maximum effective surface area S ₁ : 188.6 cm ² (15% of the maximum area S ₀ (1,257 cm ² ) of the horizontal section of the stirring tank)
・ Outer diameter d: 20 cm
・ Height b: 1.9cm
・ Inclination angle θ1: 18 °
-Maximum area S ₂ of height component: 20 × 1.9 = 38 cm ² (20% of the maximum effective surface area S ₁ (188.6 cm ² ) of the stirring main wing)
・ Wing shape: Flat plate ・ Liquid feeding method: Pressurized liquid feeding method

(Comparative Example 4)
In Example 1, except that the stirring main wing was changed to the following stirring main wing, it was converted into a carrier in the same manner as in Example 1 to obtain [Carrier 29].
A developer was produced from the obtained [Carrier 29] and [Toner 1] in the same manner as in Example 1.
<Stirring wing>
・ Rotation speed: 150rpm
・ Shape: Pitched airfoil (4 blades)
Maximum effective surface area S ₁ : 188.6 cm ² (15% of the maximum area S ₀ (1,257 cm ² ) of the horizontal section of the stirring tank)
・ Outer diameter d: 20 cm
・ Height b: 7.1 cm
・ Inclination angle θ1: 68 °
-Maximum area S ₂ of the height component: 20 × 7.1 = 142 cm ² (75% of the maximum effective surface area S ₁ (188.6 cm ² ) of the stirring main wing)
・ Wing shape: Flat plate ・ Liquid feeding method: Pressurized liquid feeding method

  Next, using the developers prepared in Examples 1 to 22 and Comparative Examples 1 to 4, the background fogging and the solid carrier adhesion over time were evaluated as follows. The results are shown in Tables 1-6.

<Skin cover>
A developer is set on a commercially available digital full-color printer (made by Ricoh Co., Ltd., imgio MPC5000), and an A4 size image with an image area of 5% is output by 1 sheet / 1000 JOB, and then an A3 size with an image area of 0%. An image was output, and the toner fog state of the background portion was observed and evaluated according to the following criteria.
〔Evaluation criteria〕
AA: No background fog A: The background fog is observable with a magnifying glass B: The background fog is almost unnoticeable to the naked eye C: Some background fog is observed D: The background fog is clearly seen

<Attachment of solid carrier over time>
The developer was set on a commercially available digital full color printer (Imagio MPC5000, manufactured by Ricoh Co., Ltd.), and a running evaluation of 300,000 sheets in a single color was performed. Then, the solid carrier adhesion of the developer after the running was evaluated.
The solid image carrier adhesion evaluation method was evaluated by fixing the background potential to 150 V using the copying machine, developing a solid image on A3 size paper, and observing with a magnifying glass. The number of white spots on the image and the total number of carriers actually attached were measured and evaluated according to the following criteria.
〔Evaluation criteria〕
AA: 0 A: 1 to 2 B: 3 to 6 C: 7 to 10 D: 11 or more

As an aspect of this invention, it is as follows, for example.
<1> A storage liquid feeding device that stores a coating liquid for coating a core material of a carrier and supplies the coating liquid to a coating device,
The coating liquid for coating contains at least a binder resin and particles,
A stirring tank having a circular horizontal section;
A baffle provided in the stirring vessel;
A stirring main wing for stirring the coating liquid for coating,
Maximum area S ₂ of the height of the component wherein the stirring wing is in storage feeding devices coating the coating liquid carrier which is a 25% to 70% of the maximum effective surface area S ₁ of the stirring wing is there.
<2> maximum effective surface area S ₁ of the stirring wing is storage of coating coating liquid carrier according to the stirring tank the is 5% to 20% of the maximum area S ₀ of the horizontal cross section of the <1> It is a liquid feeding device.
<3> The carrier liquid storage / feed device according to any one of <1> to <2>, wherein the stirring main wing is a curved plate that is curved with respect to a rotation direction.
<4> The carrier liquid storage / feed device according to any one of <1> to <3>, wherein an inclination angle θ1 of the stirring main blade is 15 ° to 60 °.
<5> the stirring wing has a stirring aileron, the agitating aileron total area S ₃ of any said more than 30% of the maximum effective surface area S ₁ of the stirring wing of <1> to <4> A device for storing and feeding a coating liquid for coating a carrier according to claim 1.
<6> The apparatus for storing and feeding a coating liquid for coating a carrier according to any one of <1> to <5>, wherein an inclination angle θ2 of the auxiliary stirring blade is 90 ° or less.
<7> The storage liquid feeding device for a coating liquid for coating a carrier according to any one of <1> to <6>, wherein the stirring tank has 2 to 6 baffles.
<8> length D ₁ of the baffle, feed storage coating coating liquid carrier according to any one of <7> 5% the a 20% <1> of the maximum inner diameter D of the stirring vessel It is a liquid device.
<9> The carrier coating liquid according to any one of <1> to <8>, wherein the carrier coating liquid is fed by injecting gas into the stirring tank and increasing the internal pressure of the stirring tank. It is a storage liquid feeding device.
<10> A carrier produced by using the storage and feeding apparatus for a coating liquid for coating a carrier according to any one of <1> to <9>.
<11> A developer comprising the carrier according to <10> and a toner.
<12> The developer according to <11>, wherein the developer contains 2 to 50 parts by mass of toner with respect to 1 part by mass of the carrier.
<13> A process cartridge having at least an electrostatic latent image carrier and developing means for developing the electrostatic latent image on the electrostatic latent image carrier with a developer to form a visible image,
The developer is the developer according to <11> or the replenishment developer according to <12>.

DESCRIPTION OF SYMBOLS 1 Stirring tank 2 Baffle 3 Stirring rotating shaft 4 Stirring main wing 5 Stirring auxiliary wing 10 Photoconductor (photosensitive drum)
10K photoconductor for black 10Y photoconductor for yellow 10M photoconductor for magenta 10C photoconductor for cyan 18 image forming means 20 roller charging means 21 exposure means 22 secondary transfer means 25 fixing means 30 exposure means 40 developing means 45K black developing means (Development unit)
45Y yellow development means (development unit)
45M Magenta development means (development unit)
45C Cyan development means (development unit)
50 Intermediate transfer body 58 Corona charger 59 Charging means 60 Cleaning means 61 Developing means 62 Transfer charger 63 Photoconductor cleaning means 64 Static eliminator 70 Static elimination means (static elimination lamp)
DESCRIPTION OF SYMBOLS 80 Transfer roller 90 Cleaning means 95 Transfer paper 100 Image forming apparatus 101 Process cartridge 110 Belt type fixing device 120 Tandem type developing means 121 Storage liquid supply device for coating liquid for carrier coating 122 Coating device 150 Copying device main body

JP-A-6-338213 Japanese Patent Laid-Open No. 7-14430

Claims (13)

A storage liquid feeding device for storing a coating liquid for coating that coats the core material of a carrier and supplying the coating liquid to a coating device,
The coating liquid for coating contains at least a binder resin and particles,
A stirring tank having a circular horizontal section;
A baffle provided in the stirring vessel;
A stirring main wing for stirring the coating liquid for coating,
The maximum area S ₂ of the height of the component stirring wing is, the storage feeding device of coating coating liquid carrier which is a 25% to 70% of the maximum effective surface area S ₁ of the stirring wing. The maximum effective surface area S ₁ of the stirring wing is, the stirring tank storage feeding device of coating coating liquid carrier according to claim 1 is 5% to 20% of the maximum area S ₀ of the horizontal section.   The storage and feeding apparatus for a coating liquid for coating a carrier according to claim 1, wherein the stirring main wing is a curved plate that is curved with respect to the rotation direction.   4. The apparatus for storing and feeding a coating liquid for coating a carrier according to claim 1, wherein an inclination angle [theta] 1 of the stirring main wing is 15 [deg.] To 60 [deg.]. Has the stirring wing is stirred ailerons, the agitating aileron total area S ₃ of the carrier according to any one of claims 1 to 4 wherein more than 30% of the maximum effective surface area S ₁ of the stirring wing Storage and feeding device for coating liquid for coating.   The storage liquid feeding device for a coating liquid for coating a carrier according to any one of claims 1 to 5, wherein an inclination angle θ2 of the auxiliary stirring blade is 90 ° or less.   The apparatus for storing and feeding a coating liquid for coating a carrier according to any one of claims 1 to 6, wherein the stirring tank has 2 to 6 baffles. The length D ₁ of the baffle, the storage feeding device of the coating coating liquid carrier according to any one of claims 1 to 7 is 5% to 20% of the maximum inside diameter D of the stirring vessel.   9. The storage and feeding apparatus for a carrier coating liquid according to claim 1, wherein the carrier coating liquid is fed by injecting gas into the stirring tank and increasing the internal pressure of the stirring tank.   A carrier manufactured using the storage liquid feeding device for a coating liquid for coating a carrier according to any one of claims 1 to 9.   A developer comprising the carrier according to claim 10 and a toner.   The developer according to claim 11, wherein the developer contains 2 to 50 parts by mass of toner with respect to 1 part by mass of the carrier. A process cartridge having at least an electrostatic latent image carrier and developing means for developing the electrostatic latent image with a developer on the electrostatic latent image carrier to form a visible image;
The process cartridge according to claim 11, wherein the developer is the developer according to claim 11 or the replenishment developer according to claim 12.