JP2014178585A - Two-component developer, image forming apparatus, and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-component developer, and others, having excellent transfer property without being influenced by a toner consumption history of the latest image for a long period of time, and having excellent durability with little decrease in chargeability due to toner spent and little changes in a carrier resistance for a long period of time.SOLUTION: The two-component developer comprises: a toner consisting of toner base particles comprising a colorant, a release agent and a binder resin, and an external additive; and a carrier. The carrier includes a core material and a coating layer covering the core material; the carrier has an arithmetic average surface roughness Ra1 of 0.50 μm to 0.90 μm; the coating layer comprises a binder resin and fine particles; and the coating layer has an average layer thickness difference of 0.02 μm to 3.0 μm. The external additive includes at least coalesced particles; the coalesced particles are aspheric secondary particles produced by coalescing primary particles; and a particle size distribution index of the coalesced particles satisfies Db/Db≤1.20.

Description

  The present invention relates to a two-component developer, an image forming apparatus, and a process cartridge.

  In recent years, the technology of copying machines and printers using an electrophotographic system is rapidly expanding from monochrome to full color, and the full color market tends to expand. In color image formation by full-color electrophotography, an electrostatic latent image is formed on an electrostatic latent image carrier, and charged toners of three colors, yellow, magenta, and cyan, are added to the electrostatic latent image. The development is performed by developing four color toners including black and forming a toner image, and then transferring and fixing the toner image onto a recording medium.

In such image formation by full color electrophotography, in order to obtain a clear full color image with excellent color reproducibility, it is necessary to keep the toner amount on the electrostatic latent image carrier faithful to the electrostatic latent image. . This is because when the amount of toner on the electrostatic latent image carrier fluctuates, the image density or the color tone of the image changes on the recording medium.
The cause of fluctuations in the toner amount on the electrostatic latent image carrier is due to fluctuations in the toner charge amount. In particular, in the hybrid development system, the difference in the toner amount on the toner carrier is as follows. It has been reported that this is due to a so-called history phenomenon (ghost phenomenon) that appears as a density difference on an image during development (see Patent Document 1).

  In the hybrid development method, as a method of eliminating the hysteresis phenomenon, after developing the electrostatic latent image on the electrostatic latent image carrier, the residual toner on the toner carrier is temporarily removed, and the surface of the toner carrier is removed. It is effective to supply a new toner to eliminate the difference in the amount of toner on the toner carrier as described above. For example, there has been proposed a method of eliminating the hysteresis phenomenon by scraping the residual toner on the toner carrier with a scraper or a toner collecting roll after developing and before resupplying the toner (see Patent Documents 2 to 4). Also proposed is a method that eliminates the hysteresis phenomenon by stabilizing the toner amount on the toner carrier by collecting the residual toner on the toner carrier on the magnetic roll by using the potential difference between copies and between papers. (See Patent Document 5). In addition, as a countermeasure against the hysteresis phenomenon using a magnetic brush, the hysteresis phenomenon is solved by stabilizing the collection and supply of toner on the developing roll by widening the full width at half maximum of the magnetic flux density of the magnetic roll. Has been proposed (see Patent Document 6). Furthermore, using a non-spherical carrier as the carrier for the two-component developer, the charge is injected up to the carrier at the tip of the magnetic brush, and the substantial distance between the developer carrier and the toner carrier is narrowed to carry the toner. By increasing the amount of toner supplied to the body at one time and supplying the toner up to the toner saturation amount on the toner carrier, the toner amount on the toner carrier is kept constant without being affected by the history of the previous image. There has been proposed a method of eliminating the history phenomenon by maintaining the above (see Patent Document 7).

  The above-mentioned hysteresis phenomenon is said to be a problem peculiar to the hybrid development system. However, even in the two-component development system, when the developer is used for a long period of time, the development ability decreases and the image density decreases. Has been reported to occur (see Patent Document 8).

The hysteresis phenomenon in the two-component development method is due to the fact that the two-component developer is not peeled off normally. The developer is peeled off by using an odd number of magnets in the developing sleeve and providing a pair of magnets of the same polarity below the rotation axis of the developing sleeve to create a peeling region where the magnetic force is almost zero. It is carried out by allowing the developer after development to drop naturally using gravity.
However, a counter charge is generated in the carrier when the amount of toner consumed in the immediately preceding image is generated, so that a mirror image force is generated between the carrier and the developer carrying member, and the developer is not normally separated in the peeling region. For this reason, the developer whose toner concentration has decreased due to toner consumption is conveyed again to the development area, and the developing ability is reduced. That is, there is a problem that the density for the first round of the sleeve is normal, whereas the density is reduced after the second round.

  As a method of eliminating the hysteresis phenomenon in the two-component development method, for example, a scooping roll having a magnet inside is arranged near the peeling area on the developing sleeve, and the developer is peeled off with the magnetic force. (See Patent Document 8). The peeled developer is pumped up by another scooping roll and then conveyed to a developer stirring chamber having a screw, where toner density is readjusted and toner is charged.

  However, according to the above proposal, since it is affected by a hysteresis phenomenon when continuously used for a long period of time, a stable toner amount cannot be supplied to the electrostatic latent image developing carrier, and it has excellent color reproducibility and a clear image. There is a problem that cannot be obtained. Further, depending on the proposal, there is a problem that the carrier resistance change due to toner spent deposition is large and the chargeability of the carrier is greatly reduced, which is a problem specific to the two-component development method. Furthermore, in order to solve the above problems, it is necessary to maintain various characteristics of the carrier so as not to cause background stains and in-machine contamination due to toner scattering. Therefore, it is strongly desired to solve such problems at the same time.

  On the other hand, the fixing of toner to a recording medium in the above-described image forming apparatus is generally a heat and heat roller system (a system in which a heating roller is directly pressed against a toner image on a recording medium and fixed in terms of energy efficiency. ) Is widely used. Toner fixing using the heating heat roller system requires a large amount of electric power for fixing. Therefore, for the purpose of energy saving, a toner having excellent low-temperature fixability that can be fixed on a recording medium at a low temperature is demanded.

  As the toner having excellent low-temperature fixability, for example, a toner using a resin having a low glass transition temperature as a binder resin has been proposed. However, since the toner using the resin having a low glass transition temperature uses a softened resin, there is a problem that it is weak in stress resistance due to development stirring and inferior in heat-resistant storage stability.

  In order to solve the heat-resistant storage problem, core particles containing a resin having a low glass transition temperature, and a shell layer (outer shell) containing a resin having a high glass transition temperature formed so as to cover the surface of the core particles There has been proposed a toner having a core-shell structure (capsule structure) having excellent heat resistance and storage stability (see Patent Documents 9 to 12). However, the toner having the core-shell structure is weak against stress during development and easily deteriorates, so that there is a problem that the transferability of the toner to a recording medium is poor.

  In order to solve the transferability problem, a toner has been proposed in which inorganic fine particles having different particle sizes are added as external additives to the surface of toner base particles (see Patent Documents 13 to 16). However, in the toner in which the inorganic fine particles having different particle diameters are added as external additives, the adhesion force of the inorganic fine particles to the toner base particles is non-uniform for each particle, and thus the toner released from the toner base particles is used. There is a problem that the inorganic fine particles contaminate the inside of the developing machine and the periphery of the photosensitive member to cause filming.

  In order to solve the filming problem, there has been proposed a toner in which amorphous particles formed by combining particles on the surface of toner base particles are added as external additives (see Patent Document 17). However, the toner to which the irregularly shaped particles are added as an external additive has a very wide particle size distribution, and there are a large amount of small particles and particles close to true spheres. However, it is easily buried in the toner base particles or detached from the toner base particles. Therefore, even with these proposals, there is a problem that transferability, filming property, and the like deteriorate.

  Therefore, two components excellent in durability without being affected by the toner consumption history of the immediately preceding image over a long period of time, and with a decrease in chargeability due to toner spent over a long period of time and a change in carrier resistance. Providing a developer is desired.

  An object of the present invention is to solve the above-described problems and achieve the following objects. In other words, the present invention is not affected by the toner consumption history of the immediately preceding image over a long period of time, and is less durable due to less deterioration in chargeability and carrier resistance due to toner spent over a long period of time. An object is to provide an excellent two-component developer.

The two-component developer of the present invention as a means for solving the above problems includes a toner comprising toner base particles containing a colorant, a release agent, and a binder resin, an external additive, and a carrier. A two-component developer comprising:
The carrier has a core and a coating layer that covers the core,
The arithmetic average surface roughness Ra1 of the carrier is 0.50 μm to 0.90 μm,
The coating layer contains a resin and fine particles, and the average layer thickness difference of the coating layer is 0.02 μm to 3.0 μm,
The external additive contains at least coalesced particles, and the coalesced particles are non-spherical secondary particles obtained by coalescing primary particles, and the particle size distribution index of the coalesced particles is expressed by the following formula: It is represented by (1).
However, in the formula (1), Db ₅₀ is the coalesced particles when the particle diameter (nm) of the coalesced particles is on the horizontal axis and the cumulative value (number%) of the coalesced particles is on the vertical axis. Represents the particle diameter of the coalesced particles having a cumulative value of 50% by number when drawn from the small particle side, and Db ₁₀ represents the particle size of the coalesced particles having the cumulative value of 10% by number. Represents the particle size.

  According to the present invention, the conventional problems can be solved, the object can be achieved, and the transferability and the toner can be maintained over a long period of time without being affected by the toner consumption history of the immediately preceding image. It is possible to provide a two-component developer excellent in durability with little decrease in chargeability due to spent and less change in carrier resistance.

FIG. 1 is a perspective view showing an example of a resistance measurement cell used for measuring the electrical resistivity of a carrier. FIG. 2 is a schematic diagram illustrating an example of a developing device. FIG. 3 is a schematic view showing an example of the image forming apparatus of the present invention. FIG. 4 is a schematic view showing another example of the image forming apparatus of the present invention. FIG. 5 is a schematic view showing an example of the process cartridge of the present invention. FIG. 6A is a diagram illustrating an example of a normal image in a vertical band chart. FIG. 6B is a diagram illustrating an example of an abnormal image in the vertical band chart. FIG. 7 is a diagram showing an example of a method for measuring the charge amount of the two-component developer of the present invention (blow-off method). FIG. 8A is a schematic diagram for explaining the interaction between the unevenness of the carrier surface and the unevenness of the external additive of the toner. FIG. 8B is a schematic diagram for explaining the interaction between the unevenness of the carrier surface and the unevenness of the external additive of the toner. FIG. 9A is a schematic diagram showing the relationship between the unevenness of the carrier surface and the toner. FIG. 9B is a schematic diagram showing the relationship between the unevenness of the carrier surface and the toner. FIG. 10 is a schematic diagram showing a state where the adhesion force between the carrier and the toner is reduced and the toner adhesion on the developer carrying member is increased. FIG. 11 is a schematic diagram showing a state in which toner cannot be held by contact with the toner at a plurality of points due to unevenness derived from the core material of the carrier, and the toner adhesion amount on the developer carrier increases. is there. FIG. 12A shows the high fluidity of the toner when there are few particles in the carrier coating layer and suppresses the burying and rolling of the external additive even when the toner is agitated and loaded on the toner. It is a model diagram which shows the state which can maintain the retention strength by contact with the carrier over time by being done. FIG. 12B shows the high fluidity of the toner when the particle size of the particles in the carrier coating layer is small. Even if the toner is agitated and a load is applied to the toner, the external additive is buried or transferred. FIG. 6 is a schematic diagram showing a state where holding force due to contact with a carrier over time can be maintained by suppressing movement. FIG. 13A-1 shows the high fluidity of the toner when a spherical external additive is used, and the external additive is buried or rolled even when the toner is agitated and a load is applied to the toner. It is a model diagram which shows the state which can maintain the retention strength by the contact with a carrier over time by being suppressed. FIG. 13A-2 realizes a high fluidity of the toner when a spherical external additive is used, and the external additive is buried or rolled even if the toner is agitated and a load is applied to the toner. It is a model diagram which shows the state which can maintain the retention strength by the contact with a carrier over time by being suppressed. FIG. 13B-1 shows the high fluidity of the toner when a non-spherical external additive (spindle type) is used, and the external additive is buried even when the toner is agitated and a load is applied to the toner. FIG. 6 is a schematic diagram showing a state where holding force due to contact with a carrier over time can be maintained by suppressing rolling and rolling. FIG. 13B-2 shows the high fluidity of the toner when a non-spherical external additive (spindle type) is used, and the external additive is buried even if the toner is agitated and a load is applied to the toner. FIG. 6 is a schematic diagram showing a state where holding force due to contact with a carrier over time can be maintained by suppressing rolling and rolling. FIG. 13C-1 shows the high fluidity of the toner when a non-spherical external additive (cohesion) is used, and the external additive is stirred even when the toner is loaded in the developing device. It is a model diagram which shows the state which can maintain the retention strength by contact with a carrier over time by burying and rolling being suppressed. FIG. 13C-2 shows the high fluidity of the toner when a non-spherical external additive (fusing) is used, and even if the toner is agitated and a load is applied to the toner, It is a model diagram which shows the state which can maintain the retention strength by contact with a carrier over time by burying and rolling being suppressed. FIG. 14 shows the high fluidity of the toner, and even if the toner is agitated and a load is applied to the toner, the embedding and rolling of the external additive are suppressed, so that It is a model diagram which shows the state which can maintain the retention strength by contact. FIG. 15 shows that the adhesion force with the developer carrier is reduced by suppressing the burying and rolling of the external additive, thereby maintaining the distance from the developer carrier and reducing the non-electrostatic adhesion force. It is a model diagram which shows the state which can be maintained. FIG. 16 shows that the adhesion to the developer carrier is suppressed by burying and rolling the external additive, thereby maintaining the distance from the developer carrier and reducing the non-electrostatic adhesion. It is a model diagram which shows the state which can be maintained. FIG. 17 is a photograph showing an example of an external additive in the toner used in the present invention. FIG. 18 is a photograph showing an example of the external additive in the toner used in the present invention. FIG. 19 is a photograph showing primary particles and secondary particles of the external additive in the toner used in the present invention. FIG. 20 is a photograph showing an example when the cohesive force of the coalesced particles is strong (when the proportion of primary particles in 1,000 coalesced particles is 30% or less). FIG. 21 is a photograph showing an example when the cohesive force of the coalesced particles is weak (when the proportion of primary particles in 1,000 coalesced particles exceeds 30%).

(Two-component developer)
The two-component developer of the present invention includes toner composed of toner base particles, an external additive, and a carrier.

The history phenomenon which is one of the problems of the present invention is different from the occurrence mechanism in the history phenomenon.
The generation mechanism of the ghost phenomenon in the present invention is not clear in detail, but is considered as follows. The toner adheres to the developer carrying member according to the immediately preceding image history, and the toner development amount of the next image varies depending on the potential of the toner attached on the developer carrying member. That is, it is considered that the toner development amount of the next image varies depending on the immediately preceding image history.
Specifically, in the non-image portion, a bias is applied from the electrostatic latent image bearing member toward the developing sleeve, so that the toner itself adheres to the developer bearing member (the toner adheres to the developer bearing member).
Since the toner developed on the development carrier has a potential, the development potential is increased by the potential of the toner on the developer carrier when the image portion is printed, and the toner development amount increases. Further, since the toner directly adhered onto the developer carrying member is consumed at the next development, the amount of toner on the developer carrying member is not constant but varies depending on the history of the immediately preceding image. That is, when there is a non-image portion or a paper-to-paper gap immediately before, the bias is applied from the electrostatic latent image carrier toward the developing sleeve when the magnetic brush passes through the region, so the image immediately after When printing a portion, the development potential increases as described above, and thus the image density increases. On the other hand, when the immediately preceding image is an image having a large image area, the toner directly attached on the developer carrying member is consumed when the immediately preceding image is developed, and the image density is lowered.
As described above, the hysteresis phenomenon which is one of the problems of the present invention is that the toner development amount on the developer bearing member fluctuates in response to the history of the immediately preceding image, and the density fluctuation of the next image appears due to the fluctuation. It is a phenomenon.

  As a result of intensive studies to achieve the above object, the present inventors have been able to suppress adhesion of the external additive added to the toner to the developer carrying member due to surface irregularities, thereby preventing the development potential from being raised and increasing the surface of the carrier. By setting the uneven shape and the unevenness of the coating layer within the specified range, the carrier hardly rolls on the developer carrying member during non-image, so that the toner development amount on the developing carrier is stabilized, and further, the carrier Since the unevenness on the surface is a predetermined value, the coated carrier can partially create a low resistance portion close to the core material resistance, and the toner developed on the developer carrier during non-image can be obtained. It was found that it is difficult to consume during printing. Even when used continuously for a long period of time, it is possible to supply a stable amount of toner without being affected by a hysteresis phenomenon, to obtain image uniformity, and to further improve the characteristics of the carrier. It was found that a carrier with excellent charge stability and low resistance change can be obtained by preventing toner spent for a long period of time.

  That is, with the configuration of the present invention, it is possible to develop a stable toner amount without being affected by the toner consumption history of the immediately preceding image over a long period of time, and to obtain a clear image with excellent color reproducibility, In addition, it has been found that a carrier satisfying the characteristics that there is little deterioration in chargeability and change in carrier resistance due to toner spent over a long period of time, and there is no occurrence of background contamination, in-machine contamination due to toner scattering, etc. can be obtained. .

Another object of the present invention is to increase the toner holding force of the carrier by strengthening the non-electrostatic bond by the interaction between the irregularities on the carrier surface and the irregularities of the external additive of the toner. Yes.
By increasing the number of contact points with the toner due to the irregularities on the carrier surface derived from the carrier core material 303, and further providing fine irregularities due to the fine particles 305 contained in the coating layer 306 on the carrier surface, an external additive for the toner It is intended to increase the toner holding force of the carrier by contacting with 302 (see FIGS. 8A and 8B). In FIG. 8A, 301 represents toner base particles, and 304 represents the difference in surface height of the carrier coating layer.
By increasing the toner holding power of the carrier, when a bias is applied from the electrostatic latent image carrier to the developing sleeve in the non-image area, the toner adheres to the developer carrier (developer carrier). And the ghost phenomenon due to the image history is suppressed.

<Career>
The carrier includes a core material and a coating layer that covers the core material, and further includes other components as necessary.

-Arithmetic average surface roughness Ra1-of the carrier
The arithmetic average surface roughness Ra1 in the carrier is 0.50 μm to 0.90 μm, and preferably 0.60 μm to 0.85 μm.
Here, the arithmetic surface roughness Ra1 represents irregularities on the carrier surface and contributes to the toner adhesion amount on the developer carrying member.
When the arithmetic average surface roughness Ra1 is less than 0.50 μm, the carrier on the developer carrier is easy to rotate, and the developer does not follow the rotation speed of the developer carrier. Developer may slip on the body. As a result, there is a speed difference between the developer carrying member and the developer, and the amount of toner adhering to the developer carrying member during non-image may increase. In addition, since the low resistance portion, that is, the coating layer is thin and there are few portions near the core material exposure, the toner developed on the developer carrying member at the time of non-image is consumed at the time of printing. The toner may fluctuate greatly.
On the other hand, when the arithmetic average surface roughness Ra1 exceeds 0.90 μm, the unevenness of the carrier itself is too large, and the wear of the carrier is biased toward the convex portion, so that the wear of the coating layer may be remarkable.
Further, regarding the relationship with the toner, when the arithmetic average surface roughness Ra1 is less than 0.50 μm, there are few contacts with the toner and the toner cannot be sufficiently retained. Further, in relation to the toner, when the arithmetic average surface roughness Ra1 exceeds 0.90 μm, the unevenness of the carrier itself is too large, so that the hazard to the toner becomes high, and the external additive 302 of the toner is increased. This is not preferable because the toner is easily embedded in the toner base particles 301 and rolling of the toner base particles 301 into the concave portions is promoted, and the function of the toner external additive 302 is easily lost (see FIGS. 9A and 9B).

  The value of the arithmetic average surface roughness Ra1 can be determined by, for example, the following measurement method. Using an OPTELICS C130 manufactured by LASERTEC, the image was captured with an objective lens magnification of 50 times and a Resolution of 0.20 μm, and the observation area was 10 μm × 10 μm centered on the top of the carrier, and 100 carriers were measured. The values obtained were used.

<Core>
The core material is not particularly limited as long as it is a magnetic material, and can be appropriately selected according to the purpose. Examples thereof include ferromagnetic metals such as iron and cobalt; iron oxides such as magnetite, hematite and ferrite; various alloys And resin particles in which a magnetic substance such as a compound is dispersed in a resin. Among these, Mn-based ferrite, Mn-Mg-based ferrite, Mn-Mg-Sr ferrite, and Mn-Mg-Ca ferrite are preferable in consideration of the environment.

-Arithmetic average surface roughness Ra2- of the core material
The arithmetic average surface roughness Ra2 of the core material defines the surface roughness of the core material.
The arithmetic average surface roughness Ra2 of the core material is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.5 μm to 1.5 μm, more preferably 0.6 μm to 1.3 μm. . When the arithmetic average surface roughness Ra2 is less than 0.5 μm, it may be difficult to obtain the desired arithmetic average surface roughness Ra1 of the carrier when carrierized, and when it exceeds 1.5 μm, When the carrier is formed, the arithmetic average surface roughness Ra1 of the carrier may become too large. On the other hand, when the arithmetic average surface roughness Ra2 is within the preferred range, it is advantageous in that the amount of toner adhered onto the developer carrying member can be controlled when the carrier is formed.
The value of the arithmetic average surface roughness Ra2 can be obtained by the same method as the measuring method of the arithmetic average surface roughness Ra1.

  The ratio Ra1 / Ra2 between the arithmetic average surface roughness Ra1 of the carrier and the arithmetic average surface roughness Ra2 of the core is not particularly limited and may be appropriately selected depending on the intended purpose. 1.0 is preferable and 0.70 to 0.90 is more preferable. When the ratio Ra1 / Ra2 is less than 0.60, it means that the unevenness of the core material of the carrier is filled when the carrier is formed, and the adhesion force between the carrier and the toner is reduced, The toner adhesion on the developer carrying member may increase (see FIG. 10), and as the value approaches 1.0, the unevenness of the core material and the unevenness of the carrier are closer. Due to the unevenness derived from the toner, the toner cannot be held by contact with the toner at a plurality of points, and the toner adhesion amount on the developer carrier increases (see FIG. 11). At the same time, the fine particles responsible for durability in the coating layer of the carrier are not sufficiently added, or even if added, the particle size is small, which means that the durability effect is insufficient. On the other hand, when the ratio Ra1 / Ra2 is within the preferred range, it is advantageous in terms of both compatibility of toner adhesion to the developer carrying member and durability.

<Coating layer>
The said coating layer contains resin and microparticles | fine-particles, and also contains another component as needed.
The coating layer can be formed by applying a coating layer forming solution containing a resin and fine particles to the core material.

  The coating layer is not particularly limited as long as it is a coating layer containing the fine particles in a proportion of 50 to 500 parts by mass with respect to 100 parts by mass of the resin, and can be appropriately selected according to the purpose. However, a coating layer containing 100 to 300 parts by mass of the fine particles with respect to 100 parts by mass of the resin is preferable. When the content of the fine particles is less than 50 parts by mass, the coating layer may be scraped. When the content exceeds 500 parts by mass, the ratio of the resin that appears on the surface of the carrier becomes relatively small, and the toner May be easily spent on the carrier surface. On the other hand, when the content is within the preferable range, it is advantageous in that the coating layer is less likely to be scraped when used for a long time in a developing machine.

  The thickness of the coating layer can be controlled by the content of the resin with respect to the core material. There is no restriction | limiting in particular as content with respect to the said core material of the said resin, Although it can select suitably according to the objective, A local low resistance state can be formed with the thickness of a coating layer, 0 0.5 mass%-3.0 mass% are preferable.

There is no restriction | limiting in particular as average thickness h of the said coating layer, Although it can select suitably according to the objective, 0.2 micrometer-2 micrometers are preferable. When the average thickness is less than 0.2 μm, when the developer is stirred in the developing machine, the core material is easily exposed on the surface of the coating layer, and the change in resistance value may increase. If it exceeds 2 μm, the convex portion of the core material is not exposed, and it may be difficult to create a local low resistance state. When the thickness is within the preferable range, it is advantageous in that a carrier having a local low resistance state can be produced.
The average thickness h of the coating layer can be obtained from the average value by observing the cross section of the carrier using a transmission electron microscope (TEM), measuring the thickness of the resin portion of the coating layer covering the carrier surface, and the like. it can. Specifically, the average of measured values can be obtained by measuring the distance from the core material surface to the coating layer surface at any 50 points from the carrier cross section.

−Average layer thickness difference−
The coating layer (carrier surface) has irregularities with an average layer thickness difference of 0.02 μm to 3.0 μm.
Here, the average layer thickness difference of the coating layer represents unevenness caused by fine particles contained in the coating layer, and contributes to carrier resistance adjustment, wear resistance, and scraping of toner spent.
If the average layer thickness difference is less than 0.02 μm, the particle size of the carrier coating layer may be small when the number of particles in the carrier coating layer is small. Since there is no adhesion due to minute contact, the toner easily moves onto the developer carrying member, which causes a ghost image (see FIGS. 12A and 12B). In addition, the toner developed on the developer carrying member at the time of non-image is consumed at the time of printing, and the toner on the developer carrying member may fluctuate greatly. Moreover, since the so-called filler effect is not sufficient, the wear resistance of the coating layer may deteriorate. Furthermore, since there is almost no unevenness on the surface of the carrier, scraping of the toner spent is not sufficient, and charging stability is also an issue.
If the average layer thickness difference is larger than 3.0 μm, the resin does not have sufficient force to constrain the fine particles. As the toner transfer increases, the ghost image deteriorates.

  The average layer thickness difference can be measured, for example, by observing the cross section of the carrier using a transmission electron microscope (TEM) and measuring the thickness of the resin portion of the coating layer covering the carrier surface. Specifically, in the cross section of the carrier, the distance from the core material surface to the coating layer surface is measured at any 50 points, and the average value of the five points and the small value of the obtained measurement values are large. The difference from the average value of 5 points.

<< Resin >>
The resin is not particularly limited and may be appropriately selected depending on the purpose. For example, acrylic resin, amino resin, polyvinyl resin, polystyrene resin, halogenated olefin resin, polyester, polycarbonate, polyethylene, polyfluoride Fluorine such as vinyl, polyvinylidene fluoride, polytrifluoroethylene, polyhexafluoropropylene, copolymers of vinylidene fluoride and vinyl fluoride, terpolymers of tetrafluoroethylene, vinylidene fluoride and non-fluorinated monomers A terpolymer, a silicone resin, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, a silicone resin is preferable.

  Moreover, as said resin, resin containing the hardened | cured material of the mixture containing a silane coupling agent and a silicone resin can also be used suitably.

  There is no restriction | limiting in particular as said silicone resin, Although it can select suitably according to the objective, At least A part represented by the following general formula (A), and B part represented by the following general formula (B) A resin containing a cross-linked product obtained by hydrolyzing a copolymer containing and producing a silanol group and condensing is preferable.

In the general formula (A), ^{R 1} represents a hydrogen atom or a methyl group,, ^{R 2} represents an alkyl group having 1 to 4 carbon atoms, m is an integer of 1 to 8 X represents a molar ratio in the copolymer, and represents 10 mol% to 90 mol%.

However, the general formula (B), ^{R 1} represents a hydrogen atom or a methyl group, ^{R 2} represents an alkyl group having 1 to 4 carbon atoms, ^{R 3} is 1 to carbon atoms 8 represents an alkyl group of 1 or an alkoxy group having 1 to 4 carbon atoms, m represents an integer of 1 to 8, Y represents a molar ratio in the copolymer, and represents 10 mol% to 90 mol. %.

The silane coupling agent has a function of stably dispersing the fine particles.
There is no restriction | limiting in particular as said silane coupling agent, According to the objective, it can select suitably, For example, r- (2-aminoethyl) aminopropyl trimethoxysilane, r- (2-aminoethyl) aminopropyl Methyldimethoxysilane, r-methacryloxypropyltrimethoxysilane, N-β- (N-vinylbenzylaminoethyl) -r-aminopropyltrimethoxysilane hydrochloride, r-glycidoxypropyltrimethoxysilane, r-mercaptopropyl Trimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, vinyltriacetoxysilane, r-chloropropyltrimethoxysilane, hexamethyldisilazane, r-anilinopropyltrimethoxysilane, vinyltrimethoxysilane, octadecyldimethyl [3 (Trimethoxysilyl) propyl] ammonium chloride, r-chloropropylmethyldimethoxysilane, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, allyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane , Dimethyldiethoxysilane, 1,3-divinyltetramethyldisilazane, methacryloxyethyldimethyl (3-trimethoxysilylpropyl) ammonium chloride, and the like. These may be used alone or in combination of two or more.

  As the silane coupling agent, an appropriately prepared product or a commercially available product may be used. Examples of the commercially available product include AY43-059, SR6020, SZ6023, SH6020, SH6026, SZ6032, SZ6050, AY43-310M, SZ6030, SH6040, AY43-026, AY43-031, sh6062, Z-6911, sz6300, sz6075, sz6079, sz6083, sz6070, sz6072, Z-6721, AY43-004, Z-6187, AY43-021 AY43-043, AY43-040, AY43-047, Z-6265, AY43-204M, AY43-048, Z-6403, AY43-206M, AY43-206E, Z6341, AY43-210MC AY43-083, AY43-101, AY43-013, AY43-158E, Z-6920, Z-6940 (manufactured by Toray Silicone Co., Ltd.), and the like. These may be used alone or in combination of two or more.

  There is no restriction | limiting in particular as content of the said silane coupling agent, Although it can select suitably according to the objective, 0.1 mass%-10 mass% are preferable with respect to the said resin. When the content is less than 0.1% by mass, the adhesiveness between the core material or the fine particles and the resin is lowered, and the coating layer may fall off during long-term use. If it exceeds 50%, toner filming may occur during long-term use.

The coating layer includes a silicone resin having at least one of the silanol group and the hydrolyzable functional group, a polymerization catalyst, and, if necessary, a silicone resin having at least one of the silanol group and the hydrolyzable functional group. It can form using the composition for coating layers containing resin other than these, and a solvent.
Specifically, it may be formed by condensing silanol groups while coating the core material with the coating layer composition, or after coating the core material with the coating layer composition, It may be formed by condensation.
The method for condensing the silanol group while coating the core material with the coating layer composition is not particularly limited and can be appropriately selected according to the purpose, for example, while applying heat, light, etc. The method of coat | covering a core material with the composition for coating layers, etc. are mentioned.
The method for condensing the silanol group after coating the core material with the coating layer composition is not particularly limited and may be appropriately selected depending on the purpose. For example, the coating layer composition The method of heating after coat | covering a core material etc. are mentioned.

<< Fine particle >>
The fine particles are not particularly limited and may be appropriately selected depending on the intended purpose, but preferably include at least one selected from alumina, silica, titanium, barium, tin, and carbon.
As the fine particles, both conductive fine particles and non-conductive fine particles can be used, and conductive fine particles and non-conductive fine particles may be used in combination.

  Here, the conductive fine particles mean fine particles having a powder specific resistance of 100 Ω · cm or less, and the nonconductive fine particles mean fine particles having a powder specific resistance exceeding 100 Ω · cm.

The powder specific resistance can be measured, for example, as follows. 5 g of a sample is put in a cylindrical vinyl chloride tube having an inner diameter of 1 inch (2.54 cm), and the upper and lower sides are sandwiched between electrodes. A pressure of 10 kg / cm ² is applied to these electrodes by a press. Subsequently, an LCR meter (4216A, manufactured by Yokogawa Hewlett-Packard Co., Ltd.) is connected in this pressurized state. The resistance r (Ω) immediately after the connection is read, the total length L (cm) is measured with a caliper, and the powder specific resistance (Ω · cm) can be calculated. The calculation formula is shown in the following formula.
Powder specific resistance (Ω · cm) = {(2.54 / 2) ² × π} × r / (L-11.35)
In the above formula, r represents the resistance immediately after connection, L represents the total length when the sample is filled, and “11.35” represents the total length when the sample is not filled.

  The conductive fine particles are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include tin dioxide, oxide on a substrate such as aluminum oxide, titanium dioxide, zinc oxide, silicon dioxide, barium sulfate, and zirconium oxide. Examples thereof include conductive fine particles formed using indium or the like as a layer; conductive fine particles formed using carbon black. Among these, conductive fine particles formed by forming a layer of tin dioxide or indium oxide on a base of aluminum oxide, titanium dioxide, or barium sulfate are preferable.

  The nonconductive fine particles are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include aluminum oxide, titanium dioxide, zinc oxide, silicon dioxide, barium sulfate, and zirconium oxide.

  The powder specific resistance of the fine particles is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably −3 Log (Ω · cm) to 3 Log (Ω · cm). If the powder specific resistance is less than −3 Log (Ω · cm), the resistance of the fine particles is too low, so that it may not be sufficiently charged during frictional charging with the toner. If it exceeds (cm), the carrier resistance adjustment capability is not sufficient, so that the edge effect and the fineness of the image may be deteriorated.

  The volume average particle diameter D of the fine particles is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 50 nm to 500 nm, and more preferably 100 nm to 400 nm. By having a volume average particle diameter D within the above-mentioned numerical range, fine particles are likely to come out from the surface of the coating layer, it is easy to make a partial low resistance, and furthermore, it is easy to scrape the spent matter on the carrier surface, wear resistance Also excellent.

The volume average particle diameter D of the fine particles can be measured using, for example, an ultracentrifugal automatic particle size distribution analyzer (CAPA-700, manufactured by Horiba, Ltd.). Specifically, the measurement is performed according to the following procedure.
First, 300 mL of a toluene solution is added to 30 mL of aminosilane (SH6020, manufactured by Toray Dow Corning Co., Ltd.) in a juicer mixer. Next, 6.0 g of the sample is added, and the mixer rotation speed is set to low and dispersed for 3 minutes. An appropriate amount of the dispersion is added to 500 mL of a toluene solution prepared in advance in a 1,000 mL beaker and diluted. The obtained diluted solution is continuously stirred with a homogenizer. Next, the volume average particle diameter is measured with an ultracentrifugal automatic particle size distribution analyzer (CAPA-700, manufactured by Horiba, Ltd.).
-Measurement conditions-
Measurement condition rotational speed: 2,000 rpm
Maximum particle size: 2.0 μm
Minimum particle size: 0.1 μm
Particle size interval: 0.1 μm
Dispersion medium viscosity: 0.59 mPa · s
Dispersion medium density: 0.87 g / cm ³
Particle density: True specific gravity value measured using a dry automatic bulk density meter (Acupic 1330, manufactured by Shimadzu Corporation)

There is no restriction | limiting in particular as content of the microparticles | fine-particles in the said coating layer, Although it can select suitably according to the objective, 50 mass parts-500 mass parts are preferable with respect to 100 mass parts of binder resin, 100 masses. Part to 300 parts by mass is more preferable.
When the content is less than 50 parts by mass, the effect of preventing the coating layer from being scraped and peeled may be reduced. When the content exceeds 500 parts by mass, the proportion of the resin that appears on the carrier surface is relatively high. The toner tends to be spent on the carrier surface. On the other hand, when the content is within the preferable range, it is possible to suppress the scraping and peeling of the coating layer when used in a developing device for a long time.

The ratio of the volume average particle diameter D of the fine particles to the average thickness h of the coating layer (D / h) is not particularly limited and may be appropriately selected depending on the intended purpose. Is preferable, and 0.1 to 1.0 is more preferable.
When the D / h is less than 0.01, there are almost no irregularities due to the fine particles, the surface of the coating film is flattened, the charging performance is deteriorated due to adhesion of the toner, and the image quality. When the value exceeds 1.0, when running in a low image area, the convex portion due to the fine particles of the coating layer is scraped, resulting in a decrease in resistance and the like. May decrease. On the other hand, when the D / h is within the preferable range, it is advantageous in that durability is good and carrier adhesion can be suppressed.

There is no restriction | limiting in particular as content in the coating layer of the said fine particle, Although it can select suitably according to the objective, 10 mass%-90 mass% are preferable, 40 mass%-85 mass% are more preferable, 50 A mass% to 80 mass% is particularly preferred.
When the content is less than 10% by mass, since the proportion of fine particles on the surface of the carrier is small, the effect of relaxing contact with a strong impact on the binder resin may be reduced, and exceeds 90% by mass. In addition, since the ratio of the binder resin on the surface of the carrier is small, the charging performance may be deteriorated, and the ability of holding the fine particles by the binder resin may be insufficient.
The content of the fine particles is represented by the following formula.
Content of fine particles (mass%) = {fine particles / (fine particles + total amount of resin solids)}

<Carrier manufacturing method>
There is no restriction | limiting in particular as a manufacturing method of the said carrier, Although it can select suitably according to the objective, The said resin and the said microparticles | fine-particles are contained in the surface of the said core material using a fluid bed type coating apparatus. The method of manufacturing by apply | coating a coating layer forming solution is preferable. In addition, when apply | coating the said coating layer forming solution, you may advance condensation of the resin contained in the said coating layer, and after apply | coating the said coating layer forming solution, condensation of the resin contained in the said coating layer You may proceed. There is no restriction | limiting in particular as the condensation method of the said resin, According to the objective, it can select suitably, For example, the method etc. which give a heat | fever, light, etc. to the said coating layer formation solution, etc. are mentioned. .

<< Volume Specific Resistance of Carrier >>
The volume resistivity of the carrier is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1 × 10 ⁹ Ω · cm or more and 1 × 10 ¹⁷ Ω · cm or less, preferably 1 × 10 ⁹ Ω. More preferably, it is from cm to 1 × 10 ¹² Ω · cm. If the volume resistivity is less than 1 × 10 ⁹ Ω · cm, the amount of toner developed on the developing carrier during non-image increases, and image uniformity may not be obtained. If the volume resistivity exceeds 1 × 10 ¹⁷ Ω · cm, the toner developed on the developer carrying member is consumed during printing, and image uniformity may not be obtained. In addition, when it falls below the measurable lower limit of the high resist meter, the volume specific resistance value is not substantially obtained, and it will be treated as a breakdown.

The volume resistivity can be measured, for example, by the following method.
First, a carrier is filled in a cell consisting of an electrode having a distance between electrodes of 2 mm and a surface area of 2 cm × 4 cm, a fluororesin container containing the electrode, and tapping is performed using a tapping machine (PTM-1 type, Sankyo Piotech Co., Ltd.). Tapping operation is performed for 1 minute at a speed of 30 times / min. Next, a DC voltage of 1,000 V was applied between the two electrodes, and the DC resistance was measured with a high resist meter [high resistance meter 4329A (4329A + LJK5HVLVWDQFH, Yokogawa Hewlett-Packard Co., Ltd.)] to obtain the electrical resistivity RΩ · cm. , LogR can be calculated.

<< Weight average particle diameter Dw of carrier >>
The weight average particle diameter Dw of the carrier refers to a particle diameter at an integrated value of 50% in the particle size distribution of the core obtained by a laser diffraction / scattering method.
There is no restriction | limiting in particular as the weight average particle diameter Dw of the said carrier, Although it can select suitably according to the objective, 20 micrometers-65 micrometers are preferable. When the weight average particle diameter is within the above range, the effect of improving carrier adhesion, image quality, etc. is remarkable. This is not preferable when the weight average particle size is less than 20 μm, because the uniformity of the particles is lowered and a technique for sufficiently using the machine side has not been established, causing problems such as carrier adhesion. On the other hand, if the weight average particle diameter exceeds 65 μm, the reproducibility of image details is poor and a fine image cannot be obtained, which is not preferable.

The weight average particle diameter Dw is calculated based on the particle diameter distribution (relationship between the number frequency and the particle diameter) of the particles measured on the basis of the number.
The weight average particle diameter Dw is represented by the following formula (1).
Dw = {1 / Σ (nD ² )} × {Σ (nD ⁴ )} (1)
(In the above formula (1), D represents the representative particle size (μm) of particles present in each channel, and n represents the total number of particles present in each channel.)
The channel indicates a length for dividing the particle size range in the particle size distribution diagram into measurement width units. In the present invention, the channel has an equal length of 2 μm (particle size distribution width). Adopted.
Further, as the representative particle size of the particles existing in each channel, the lower limit value of the particle size stored in each channel was adopted.

The number average particle diameter Dp is calculated based on the particle size distribution of the particles measured on the basis of the number.
The number average particle diameter Dp is represented by the following formula (2).
Dp = (1 / N) × (ΣnD) (2)
In the above formula (2), N represents the total number of particles measured, n represents the total number of particles present in each channel, and D represents the lower limit value of the particle size present in each channel (2 μm). .

As a particle size analyzer for measuring the particle size distribution, for example, a Microtrac particle size analyzer (model HRA9320-X100, manufactured by Honeywell) was used. The measurement conditions are as follows.
-Measurement conditions-
[1] Particle size range: 100 nm to 8 μm
[2] Channel length (channel width): 2 μm
[3] Number of channels: 46
[4] Refractive index: 2.42

<< Carrier magnetization >>
The magnetization of the carrier (magnetic moment) is not particularly limited and may be appropriately selected depending on the purpose, in a magnetic field of ^{1kOe, 40Am 2 / kg~90Am 2 /} kg is preferred.
For the measurement of the magnetization, for example, a highly sensitive vibration sample type magnetometer (VSM-P7-15, manufactured by Toei Industry Co., Ltd.) can be used. As a specific measurement method, about 0.15 g of a carrier is weighed, a cell having an inner diameter of 2.4 mm and a height of 8.5 mm (see FIG. 1) is filled with the carrier, and a magnetic field of 1,000 oerste (Oe) is obtained. Measure below. In FIG. 1, 201a represents an electrode, 201b represents an electrode, 202 represents a fluororesin container, and 203 represents a carrier.

<Toner>
The toner includes toner base particles containing a colorant, a release agent, and a binder resin, and an external additive.
The toner of the present invention achieves high fluidity of the toner, and even when a load is applied to the toner, such as stirring in a developing device, the embedding and rolling of the external additive are suppressed, so that The holding force due to contact with the carrier can be maintained (see FIGS. 13A-1 to 13C-1 and FIG. 14).
13A-1 and 13A-2 show the case where a spherical external additive is used, and FIGS. 13B-1 and 13B-2 show the case where a non-spherical external additive (spindle type) is used. 13C-2 shows the case where a non-spherical external additive (attachment) is used.
As shown in FIG. 14, when a spherical external additive is used, contact between the surface irregularities of the carrier surface layer and the toner external additive may not be sufficiently obtained due to burying or rolling of the external additive.

Further, regarding the adhesion force with the developer carrier, the adhesion to the developer carrier is increased by increasing the distance from the developer carrier by suppressing the burying and rolling of the external toner additive. Can be kept low (see FIG. 15).
In addition, regarding the adhesion force with the developer carrier, the non-electrostatic adhesion force is reduced by maintaining the distance from the developer carrier by suppressing the embedding and rolling of the toner external additive. Can be maintained (see FIG. 16).
In other words, by suppressing the burying and rolling of the external additive, the holding force (adhesive force) between the carrier is kept large, and the adhesive force with the developer carrier is kept low. When a bias is applied from the electrostatic latent image carrier to the developing sleeve, the toner is prevented from directly adhering to the developer carrier (development to the developer carrier), and depending on the image history. It is characterized by suppressing the ghost phenomenon.

  In general, when a small particle size toner is used in an electrophotographic image forming apparatus, the non-electrostatic adhesion between the toner particles and the electrostatic latent image carrier or between the toner particles and the intermediate transfer member increases. Therefore, the transfer efficiency is further reduced. In particular, when a small-diameter toner is used in a high-speed machine, non-electrostatic adhesion to the intermediate transfer member is increased by reducing the particle diameter of the toner, and the transfer nip portion, It is known that the transfer efficiency in the secondary transfer is significantly reduced because the time during which the toner particles are subjected to the transfer electric field in the nip portion of the secondary transfer is shortened.

  However, in the toner, the non-electrostatic adhesion force of the toner particles is reduced by reducing the base of the external additive, and the fixing property is inhibited even when the transfer time is shortened as in a high-speed machine. Sufficient transfer efficiency can be obtained without this. Furthermore, even when the mechanical stress over time is large as in a high-speed machine, the external additive itself is difficult to roll, so the external additive does not roll into the recess, and the function of the external additive is not lost. In addition, sufficient transfer efficiency can be maintained.

<External additive>
The external additive is not particularly limited as long as it contains at least coalesced particles, and can be appropriately selected according to the purpose.

<< coalescence particles >>
The coalesced particles are non-spherical secondary particles obtained by coalescing primary particles.
The external additive only needs to include at least the coalesced particles (secondary particles), and in addition to the coalesced particles (secondary particles), the external additives include those in the state of primary particles of the coalesced particles. May be.

-Primary particles-
The primary particles are not particularly limited and can be appropriately selected depending on the purpose. For example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, Tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride, etc. Inorganic fine particles, organic fine particles, and the like. These may be used individually by 1 type and may use 2 or more types together. Among these, silica is preferable in that the external additive can be prevented from being buried and detached from the toner base particles.

  There is no restriction | limiting in particular as a volume average particle diameter (Da) of the said primary particle, Although it can select suitably according to the objective, 20 nm-150 nm are preferable and 35 nm-150 nm are more preferable. When the primary particle is less than 20 nm, the function of the spacer effect cannot be achieved, and the embedding of the external additive in the toner base particle due to external stress may not be suppressed. Separation is likely to occur, and photoconductor filming is likely to occur.

  The volume average particle diameter (Da) of the primary particles was measured based on the particle diameter of primary particles in the coalesced particles (the length of all arrows shown in FIG. 17). In the measurement, a sample obtained by dispersing the secondary particles in an appropriate solvent (tetrahydrofuran (THF) or the like) and then removing the solvent on the substrate to dry the solid particles was subjected to a field emission scanning electron microscope (FE-). SEM, acceleration voltage: 5 kV to 8 kV, observation magnification: 8,000 times to 10,000 times), and measuring the particle diameter of primary particles in the visual field. The particle diameter of the primary particles is measured by measuring the average value of the longest length of all the aggregated particles (the length of all arrows shown in FIG. 17) (the number of particles measured: 100 or more and 200 or less). To do.

-Secondary particles-
The secondary particles are as described above, that is, coalesced particles.
The secondary particle is not particularly limited as long as it is a particle obtained by chemically bonding the primary particles with a treatment agent described later and secondary agglomerated, and can be appropriately selected according to the purpose. Silica is preferred.

  The volume average particle diameter (Db) of the secondary particles is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 80 nm to 200 nm, more preferably 100 nm to 180 nm, and particularly preferably 100 nm to 160 nm. preferable. When the volume average particle diameter is less than 80 nm, it is difficult to achieve the function of the spacer effect, and it is difficult to suppress burying due to external stress. When the volume average particle diameter exceeds 200 nm, release from the toner is likely to occur, which causes photoconductor filming. It becomes easy.

  The volume average particle diameter (Db) of the secondary particles can be measured, for example, by dispersing the secondary particles in an appropriate solvent (tetrahydrofuran (THF) or the like) and then removing the solvent on the substrate to dry it. The particle size of the coalesced particles in the field of view is measured with a field emission scanning electron microscope (FE-SEM, acceleration voltage: 5 kV to 8 kV, observation magnification: 8,000 times to 10,000 times). By doing. The particle diameter of the secondary particles is measured by measuring the longest length of aggregated particles (the length of the arrow shown in FIG. 18) (measured number of particles: 100 or more and 200 or less).

−Fusion degree of coalescence particles−
The degree of coalescence (G) is the ratio of the volume average particle diameter of the coalesced particles (secondary particles) to the volume average particle diameter of the primary particles contained in the coalesced particles (volume average particle of secondary particles). Diameter / volume average particle diameter of primary particles), and each volume average particle diameter is measured and calculated by the method described above.

  The degree of coalescence (G) of the coalesced particles (volume average particle diameter of secondary particles / volume average particle diameter of primary particles) is not particularly limited and may be appropriately selected depending on the intended purpose. .5 to 4.0 is preferable, and 2.0 to 3.0 is more preferable. When the degree of coalescence (G) is less than 1.5, the external additive tends to roll into the recesses on the surface of the toner base particles, and may not be excellent in transferability. In addition, the external additive is easily peeled off from the toner, and carrier contamination and the photoconductor are damaged.

  The content of the coalesced particles having a coalescence degree of less than 1.3 in the toner is not particularly limited and may be appropriately selected depending on the intended purpose. It is preferably 10% by number or less. The coalesced particles have a distribution in production, and the particles having a coalescence degree of less than 1.3 are particles that have not undergone coalescence, and are present in a substantially spherical state. . For this reason, it is difficult to perform the function as a variant additive characterized for suppressing burial. The measurement of the content of the coalesced particles having a coalescence degree of less than 1.3 is performed by measuring the volume average particle diameter of the primary particles and the secondary particles by 100 or more and 200 or less by the above-described method. The degree of coalescence of each coalesced particle is calculated from the obtained measured value, and the number of particles with the degree of coalescence less than 1.3 is divided by the number of measurements.

-Particle size distribution index of coalesced particles-
By using particles satisfying the following formula (1) as the particle size distribution index of the coalesced particles, the problem of filming property in the toner can be solved. By using particles having a sharp particle size distribution as represented by the following formula (1) as the coalesced particles, a toner having particularly excellent filming properties can be obtained.
However, in the formula (1), Db ₅₀ is the coalesced particles when the particle diameter (nm) of the coalesced particles is on the horizontal axis and the cumulative value (number%) of the coalesced particles is on the vertical axis. Represents the particle diameter of the coalesced particles having a cumulative value of 50% by number when drawn from the small particle side, and Db ₁₀ represents the particle size of the coalesced particles having the cumulative value of 10% by number. Represents the particle size.

The Db ₅₀ is represented, for example, by the cumulative distribution of the coalesced particles when the horizontal axis is the particle diameter (nm) of the coalesced particles and the cumulative value (number%) of the coalesced particles is the vertical axis. If the measured number of the coalesced particles is 200, it means the particle diameter of the 100th particle, and if it is 150, the particle size of the 75th coalesced particle.

The Db ₅₀ is measured by dispersing the coalesced particles in an appropriate solvent (tetrahydrofuran (THF) or the like), removing the solvent on the substrate and drying the sample, and then using a field emission scanning electron microscope. (FE-SEM, acceleration voltage: 5 kV to 8 kV, observation magnification: 8,000 times to 10,000 times) The particle diameter of coalesced particles in the visual field is measured, and the cumulative value becomes 50%. This is done by measuring the particle size of the coalesced particles. The particle diameter of the coalesced particles is determined by measuring the longest length of aggregated particles (the length of the arrow shown in FIG. 18) (measured number of particles: 100 or more and 200 or less).

The Db ₁₀ is represented by, for example, the cumulative distribution of the coalesced particles when the particle diameter (nm) of the coalesced particles is on the horizontal axis and the cumulative value (number%) of the coalesced particles is on the vertical axis. If the measured number of particles of the coalesced particles is 200, the particle size of the coalesced particles is the 20th, and if it is 150, the particle size of the fifteenth coalesced particles.

The Db ₁₀ is measured by dispersing the coalesced particles in an appropriate solvent (tetrahydrofuran (THF) or the like), and then removing the solvent on the substrate to dry the sample, using a field emission scanning electron microscope (FE-SEM, acceleration voltage: 5 kV to 8 kV, observation magnification: 8,000 times to 10,000 times) The particle diameter of coalesced particles in the visual field is measured, and the cumulative value becomes 10%. This is done by measuring the particle size of the coalesced particles. The particle diameter of the coalesced particles is determined by measuring the longest length of aggregated particles (the length of the arrow shown in FIG. 18) (measured number of particles: 100 or more and 200 or less).

The “Db ₅₀ / Db ₁₀ ” is not particularly limited as long as it is 1.20 or less, and can be appropriately selected according to the purpose, but is preferably 1.15 or less. When the “Db ₅₀ / Db ₁₀ ” exceeds 1.20, the particle size distribution of the coalesced particles is wide and the number of particles having a small particle size increases. That is, “small particle A” (particles that are not coalesced and exist in the form of primary particles) or “small particle B” (coagulant is advancing, but primary particles This means that at least one of the particles having a small particle size is large. If the “small particle A” is large, the function as a non-spherical external additive cannot be achieved and the burial resistance is poor, and thus an abnormal image may occur. When the amount of “B” is large, the function of the spacer effect cannot be achieved, and the burying of the external additive in the toner base particles due to external stress may not be suppressed. Therefore, it is necessary to reduce the “small particle A” and the “small particle B”.

  The method for reducing the “small particle A” and the “small particle B” is not particularly limited and may be appropriately selected depending on the intended purpose. A method of removing particles having a diameter is preferable.

-Shape of coalesced particles-
The shape of the coalesced particle is not particularly limited as long as it has a non-spherical shape obtained by coalescing particles, and can be appropriately selected according to the purpose. For example, FIGS. As shown, a non-spherical shape in which two or more particles are coalesced is exemplified. By using the coalesced particles, high fluidity of the toner is realized, and the embedding and rolling of the external additive are suppressed even when a load is applied to the toner such as stirring in the developing device. Thus, it is possible to maintain a high transfer rate over time. Further, the coalesced particles have high toner durability because the cohesive force (cohesive force) between the particles is maintained even under a constant stirring condition.

-Parameters of coalesced particles-
The coalesced particles are not particularly limited as long as the following formula (2) is satisfied, and can be appropriately selected according to the purpose, but it is preferable to satisfy the following formula (2-1).
Since the coalesced particles maintain the cohesive force (cohesive force) between the primary particles even under a constant stirring condition, the durability of the toner is enhanced.
However, in the formula (2) and the formula (2-1), Nx represents the number of primary particles in 1,000 particles of the external additive. The number of primary particles in 1,000 particles was agitated with a mixing stirrer at 67 Hz for 10 minutes with respect to 0.5 g of the external additive and 49.5 g of the carrier placed in a 50 mL bottle. Then, it observes and measures with a scanning electron microscope.

  When the cohesive force of the coalesced particles is strong (as shown in FIG. 20, the proportion of primary particles (for example, the particles indicated by reference numeral 4 in FIG. 20) in the 1,000 coalesced particles is 30%. In the case where the external additive in the toner is cracked or disintegrated by a load such as a developing device, the number of primary particles is reduced, and the embedding and rolling of the external additive are suppressed, and the time-lapse of the external additive is suppressed. High transfer rate can be maintained.

  When the cohesive force of the coalesced particles is weak (as shown in FIG. 21, the proportion of primary particles (for example, the particles indicated by reference numeral 4 in FIG. 21) occupying 1,000 of the coalesced particles is 30%. The external additive in the toner is cracked or disintegrated by a load such as a developing device, and the number of primary particles increases, the ratio of spherical primary particles increases, the movement of the external additive, Buried easily occurs, and it becomes difficult to maintain a high transfer rate over time.

--- Formula (2) Conditions ---
In the formula (2), the primary particles are particles that have become primary particles due to cracking or disintegration after the coalesced particles are stirred under the stirring conditions using the mixing stirrer, and the stirring is performed. Particles that have been present solely from the primary particles from the front, for example, particles in which the primary particles are not coalesced, such as the particles indicated by reference numeral 2 in FIG. 19 and reference numeral 4 in FIGS. Etc. are included. In addition, the particle | grains shown with the code | symbol 1 of FIG. 19, and the code | symbol 3 of FIGS. 20-21 are secondary particles.
In the formula (2), the shape of the primary particles is not particularly limited as long as the particles are not bonded together, and can be appropriately selected according to the purpose. 2. In many cases, the particles are present in a substantially spherical state like the particles indicated by reference numeral 4 in FIGS.

In the formula (2), the method for confirming the presence of the primary particles is not particularly limited and may be appropriately selected depending on the intended purpose, but is observed with a scanning electron microscope (SEM). Therefore, a method of confirming that the particles are present alone is preferable.
There is no restriction | limiting in particular as a measuring method of the volume average particle diameter of the said primary particle, Although it can select suitably according to the objective, A scanning electron microscope (FE-SEM, acceleration voltage: 5 kV-8 kV, observation magnification: 8) The average particle diameter of the primary particles in the field of view is measured (measured number of particles: 100 or more).

In the above formula (2), as the measurement of the primary particles in 1,000 particles, after stirring, the particles are observed with a scanning electron microscope, code 2 in FIG. 19, code 4 in FIGS. Like the particle | grains shown by (4), the particle | grains which exist only by particle | grains are measured as one primary particle.
In the formula (2), when measuring 1,000 particles, if the coalesced particles formed by coalescing a plurality of particles are confirmed by the scanning electron microscope, the coalesced particles are particles. Measure as one.

In the formula (2), a rocking mill (manufactured by Seiwa Giken Co., Ltd.) is used as the mixing stirrer.
In the formula (2), the carrier is not particularly limited and may be appropriately selected depending on the intended purpose, but a coating layer forming solution of an acrylic resin and a silicone resin containing alumina particles is applied to the surface of the sintered ferrite powder. It is preferable to use coated ferrite powder obtained by drying.
In said Formula (2), there is no restriction | limiting in particular as said 50 mL bottle, According to the objective, it can select suitably, For example, the commercially available glass bottle (made by Nidec Rika Glass Co., Ltd.) etc. are mentioned.

--Characteristics of coalesced particles--
The degree of coalescence of the coalesced particles (volume average particle diameter of secondary particles / volume average particle diameter of primary particles) is not particularly limited and may be appropriately selected depending on the intended purpose. 4.0 is preferred. When the degree of coalescence is less than 1.5, the external additive tends to roll into the recesses on the surface of the toner base particles and may not be excellent in transferability. Since the external additive is easily peeled off, it may cause carrier contamination and damage to the photoconductor, which may cause image defects over time.

  The method for confirming that the primary particles of the coalesced particles are coalesced is not particularly limited and can be appropriately selected according to the purpose, but is observed with a scanning electron microscope (SEM). Thus, a method of confirming that the primary particles are coalesced is preferable.

  By using the coalesced particles, high fluidity of the toner is realized, and the embedding and rolling of the external additive are suppressed even when a load is applied to the toner such as stirring in the developing device. Thus, it is possible to maintain a high transfer rate over time.

  There is no restriction | limiting in particular as a method to confirm that the particle | grains of the said coalesced particle are coalesced, Although it can select suitably according to the objective, A field emission type | mold scanning electron microscope (FE-SEM) The method of confirming by observing at is preferable.

-Manufacturing method of coalesced particles-
The method for producing the coalesced particle is not particularly limited and may be appropriately selected depending on the intended purpose. However, a method of producing by a sol-gel method is preferable, and specifically, the primary particle and the following will be described. A method of producing a secondary particle (fused particle) by chemical bonding by mixing or firing with a treatment agent to cause secondary aggregation is preferable. When synthesizing by the sol-gel method, coalescent particles may be prepared by a one-step reaction in the presence of the treatment agent.

-Treatment agent-
There is no restriction | limiting in particular as said processing agent, According to the objective, it can select suitably, For example, a silane processing agent, an epoxy processing agent, etc. are mentioned. These may be used alone or in combination of two or more. When silica is used as the primary particles, the Si—O—Si bond formed by the silane-based treatment agent is more heated than the Si—O—C bond formed by the epoxy-based treatment agent. From the viewpoint of stability, a silane-based treatment agent is preferable. Moreover, you may use processing adjuvants (water, 1 mass% acetic acid aqueous solution, etc.) as needed.

--- Silane treatment agent ---
There is no restriction | limiting in particular as said silane type processing agent, According to the objective, it can select suitably, For example, alkoxysilanes (tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxy) Silane, dimethyldiethoxysilane, methyldimethoxysilane, methyldiethoxysilane, diphenyldimethoxysilane, isobutyltrimethoxysilane, decyltrimethoxysilane, etc.); silane coupling agents (γ-aminopropyltolethoxysilane, γ-glycidoxy) Propyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, vinyltriethoxysilane, methylvinyldi Methoxysilane, etc.); vinyltrichlorosilane, dimethyldichlorosilane, methylvinyldichlorosilane, methylphenyldichlorosilane, phenyltrichlorosilane, N, N′-bis (trimethylsilyl) urea, N, O-bis (trimethylsilyl) acetamide, dimethyltrimethylsilyl Examples thereof include a mixture of amine, hexamethyldisilazane, and cyclic silazane.

As shown below, the silane-based treatment agent causes the primary particles (for example, silica primary particles) to form chemical bonds to form secondary aggregation.
When the silica primary particles are treated using the alkoxysilanes, the silane coupling agent, or the like as the silane treatment agent, as shown in the following formula (A), a silanol group bonded to the silica primary particles And an alkoxy group bonded to the silane-based treatment agent react to form a new Si—O—Si bond by dealcoholization and secondary aggregation.
When the silica primary particles are treated with the chlorosilanes as the silane-based treatment agent, the chloro group of the chlorosilanes and the silanol group bonded to the silica primary particles are dehydrochlorinated to form new Si. The silanol group bonded to —O—Si forms a new Si—O—Si bond by the dehydration reaction, and secondarily aggregates. Further, when the silica primary particles are treated with the chlorosilanes as the silane-based treatment agent, when water coexists in the system, the chlorosilanes are first hydrolyzed into water to generate silanol groups, The silanol groups bonded to the silanol groups and the silica primary particles form a new Si—O—Si bond by the dehydration reaction, and are secondarily aggregated.
When the silica primary particles are treated with silazanes as the silane treatment agent, a new Si-O-Si bond is formed by deammoniation of the silanol groups bonded to the amino groups and the silica primary particles. Secondary aggregation.
However, in said formula (A), R shows an alkyl group.

--- Epoxy-based treatment agent ---
The epoxy-based treatment agent is not particularly limited and can be appropriately selected according to the purpose. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, Examples thereof include bisphenol A novolac type epoxy resins, bisphenol type epoxy resins, glycidylamine type epoxy resins, and alicyclic epoxy resins.

  As shown in the following formula (B), the epoxy treating agent chemically bonds the silica primary particles to form secondary aggregation. When the silica primary particles are treated using the epoxy-based treatment agent, silanol groups bonded to the silica primary particles add an epoxy group oxygen atom and a carbon atom bonded to the epoxy group of the epoxy-based treatment agent. Thus, a new Si—O—C bond is formed and secondary aggregation occurs.

  There is no restriction | limiting in particular as mixing mass ratio (primary particle: treatment agent) of the said processing agent and the said primary particle, Although it can select suitably according to the objective, 100: 0.01-100: 50 is preferable. . In addition, there exists a tendency for a coalescence degree to become high, so that there is much quantity of the said processing agent.

  There is no restriction | limiting in particular as a mixing method of the said processing agent and the said primary particle, According to the objective, it can select suitably, For example, the method of mixing with a well-known mixer (spray dryer etc.) etc. are mentioned. When mixing, the primary particles may be prepared and then mixed with the treatment agent, or when the primary particles are prepared, the treatment agent is allowed to coexist and prepared in a one-step reaction. May be.

  There is no restriction | limiting in particular as baking temperature of the said processing agent and the said primary particle, Although it can select suitably according to the objective, 100 to 2500 degreeC is preferable. In addition, it exists in the tendency for a coalescence degree to become high, so that the said baking temperature is high.

  There is no restriction | limiting in particular as baking time of the said processing agent and the said primary particle, Although it can select suitably according to the objective, 0.5 to 30 hours are preferable.

  There is no restriction | limiting in particular as content of the said external additive, Although it can select suitably according to the objective, 0.5 mass part-4.0 mass parts are preferable with respect to 100 mass parts of toner base particles. .

<Toner base particles>
The toner base particles contain at least a colorant, a release agent, and a binder resin, and further contain other components as necessary.

<< Binder resin >>
There is no restriction | limiting in particular as said binder resin, According to the objective, it can select suitably, For example, a polyester resin, a silicone resin, a styrene-acryl copolymer resin, a styrene resin, an acrylic resin, an epoxy resin, a diene resin Phenol resin, terpene resin, coumarin resin, amidoimide resin, butyral resin, urethane resin, ethylene-vinyl acetate copolymer resin, and the like. These may be used individually by 1 type and may use 2 or more types together. Among these, polyester resin, polyester resin and the above-mentioned other binder resins are combined in that they have excellent low-temperature fixability, can smooth the image surface, and have sufficient flexibility even when the molecular weight is lowered. Resins are particularly preferred.

-Polyester resin-
There is no restriction | limiting in particular as said polyester resin, Although it can select suitably according to the objective, An unmodified polyester resin and a modified polyester resin are preferable. It is preferable that at least a part of the unmodified polyester resin and the modified polyester resin are compatible with each other in terms of improving low-temperature fixability and hot offset resistance. For this reason, it is preferable that the modified polyester resin and the unmodified polyester resin have similar compositions.

--Unmodified polyester resin--
There is no restriction | limiting in particular as said unmodified polyester resin, According to the objective, it can select suitably, For example, unmodified polyester resins, such as a crystalline polyester resin and an amorphous polyester resin, etc. are mentioned.

  There is no restriction | limiting in particular as an acid value of the said unmodified polyester resin, Although it can select suitably according to the objective, 1KOHmg / g-50KOHmg / g are preferable, and 5KOHmg / g-30KOHmg / g are more preferable. When the acid value exceeds 50 KOHmg / g, the charging stability, particularly the charging stability against environmental fluctuations may be lowered. On the other hand, when the acid value is in a preferred range, it is advantageous in that the charging stability is excellent, the affinity between the paper and the toner is improved at the time of fixing to the paper, and the low-temperature fixing property is improved.

There is no restriction | limiting in particular as a hydroxyl value of the said non-modified polyester resin, Although it can select suitably according to the objective, 5 KOHmg / g or more is preferable. Examples of the method for measuring the hydroxyl value include a method of measuring using a method based on JIS K0070-1966.
The measurement method will be specifically described. First, 0.5 g of a sample is precisely weighed into a 100 mL volumetric flask, and 5 mL of an acetylating reagent is added thereto. Next, after heating in a warm bath at 100 ° C. ± 5 ° C. for 1 to 2 hours, the flask is removed from the warm bath and allowed to cool. Furthermore, water is added and shaken to decompose acetic anhydride. Next, in order to completely decompose acetic anhydride, the flask is again heated in a warm bath for 10 minutes or more and allowed to cool, and then the wall of the flask is thoroughly washed with an organic solvent. Furthermore, using a potentiometric automatic titrator (DL-53 Titrator, manufactured by METTLER TOLEDO) and an electrode DG113-SC (manufactured by METTLER TOLEDO), the hydroxyl value was measured at 23 ° C. and analyzed software (LabX Light Version 1). 0.00.000). The calibration of the apparatus uses a mixed solvent of 120 mL of toluene and 30 mL of ethanol. The measurement conditions of the hydroxyl value are as shown in Table A.

--- Method for synthesizing unmodified polyester resin ---
The method for synthesizing the unmodified polyester resin is not particularly limited and may be appropriately selected depending on the purpose. For example, the polyol represented by the following general formula (1) and the following general formula (2) And a method of synthesizing the resulting polycarboxylic acid by polyesterification.
However, in the said General formula (1), A represents the aromatic group or heterocyclic aromatic group which may have a C1-C20 alkyl group, an alkylene group, and a substituent, m is 2- Represents an integer of 4.
However, in said general formula (2), B represents the C1-C20 alkyl group, alkylene group, the aromatic group which may have a substituent, or a heterocyclic aromatic group, and n is 2-2. Represents an integer of 4.

---- Polyol ----
There is no restriction | limiting in particular as a polyol represented by the said General formula (1), According to the objective, it can select suitably, For example, ethylene glycol, diethylene glycol, triethylene glycol, 1, 2- propylene glycol, 1, 3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene Glycol, polypropylene glycol, polytetramethylene glycol, sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, bisphenol A, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, hydrogenated bisphenol A, hydrogenated bisphenol A ethylene oxide adduct, hydrogenated bisphenol A propylene oxide adduct, and the like. These may be used alone or in combination of two or more.

---- Polycarboxylic acid ----
There is no restriction | limiting in particular as polycarboxylic acid represented by the said General formula (2), According to the objective, it can select suitably, For example, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalate Acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, n-dodecenyl succinic acid, isooctyl succinic acid, isododecenyl succinic acid, n-dodecyl succinic acid, isododecyl succinic acid , N-octenyl succinic acid, n-octyl succinic acid, isooctenyl succinic acid, isooctyl succinic acid, 1,2,4-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-di Ruboxyl-2-methyl-2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, empor trimer Acid, cyclohexanedicarboxylic acid, cyclohexenedicarboxylic acid, butanetetracarboxylic acid, diphenylsulfonetetracarboxylic acid, ethylene glycol bis (trimellitic acid), and the like can be given. These may be used alone or in combination of two or more.

--Modified polyester resin--
The modified polyester resin is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the “active hydrogen group-containing compound” and the “polymer capable of reacting with the active hydrogen group-containing compound” are elongated. Examples thereof include resins obtained by reaction or crosslinking reaction.

--- Active hydrogen group-containing compound ---
The “active hydrogen group-containing compound” is a compound that acts as an elongation agent, a crosslinking agent, or the like when the “polymer capable of reacting with the active hydrogen group-containing compound” undergoes an elongation reaction or a crosslinking reaction in an aqueous phase. Any compound having an active hydrogen group is not particularly limited and may be appropriately selected depending on the intended purpose. The above-mentioned “polymer capable of reacting with an active hydrogen group-containing compound” will be described later. In the case of a prepolymer, amines are preferable in terms of enabling high molecular weight.

  There is no restriction | limiting in particular as said active hydrogen group, According to the objective, it can select suitably, For example, a hydroxyl group (alcoholic hydroxyl group or phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group etc. are mentioned. These may be contained singly or in combination of two or more.

  The amines that are the active hydrogen group-containing compounds are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include diamines, trivalent or higher polyamines, amino alcohols, amino mercaptans, amino acids, and the like. Examples include those obtained by blocking the amino group of amines. Examples of the diamine include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexylmethane, diamines). Cyclohexane, isophoronediamine, etc.); aliphatic diamines (ethylenediamine, tetramethylenediamine, hexamethylenediamine, etc.), and the like. Examples of the trivalent or higher polyamine include diethylenetriamine and triethylenetetramine. Examples of the amino alcohol include ethanolamine and hydroxyethylanily. Examples of the amino mercaptan include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid include aminopropionic acid and aminocaproic acid. Examples of the blocked amino groups of these amines include, for example, any of these amines (diamine, trivalent or higher polyamine, amino alcohol, amino mercaptan, amino acid, etc.) and ketones (acetone, methyl ethyl ketone, And ketimine compounds obtained from methyl isobutyl ketone and the like, and oxazolidone compounds. These may be used individually by 1 type and may use 2 or more types together. Among these, diamine and a mixture of diamine and a small amount of trivalent or higher polyamine are preferable.

--- Polymer capable of reacting with active hydrogen group-containing compound ---
The “polymer capable of reacting with the active hydrogen group-containing compound” is not particularly limited as long as it is a polymer having at least a group capable of reacting with the “active hydrogen group-containing compound”, and is appropriately selected depending on the purpose. However, it is excellent in high fluidity and transparency at the time of melting, is easy to adjust the molecular weight of the polymer component, and is excellent in low-temperature fixability and releasability. An isocyanate group-containing polyester prepolymer (hereinafter referred to as “polyester prepolymer”) is more preferable.

  The average number of isocyanate groups contained per molecule of the polyester prepolymer is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1 or more, more preferably 1.2 to 5, 1.5 to 4 is particularly preferable. When the average number is less than 1, the molecular weight of the polyester resin (RMPE) modified with a urea bond-forming group is lowered, and the hot offset resistance may be deteriorated.

The weight average molecular weight Mw of the polyester prepolymer is not particularly limited and may be appropriately selected depending on the intended purpose. 4,000 to 40,000 is preferable, and 4,000 to 30,000 is more preferable. When the weight average molecular weight Mw is less than 3,000, the heat resistant storage stability may be deteriorated, and when it exceeds 40,000, the low temperature fixability may be deteriorated.
The weight average molecular weight Mw can be measured, for example, as follows. First, the column was stabilized in a 40 ° C. heat chamber, and at this temperature, tetrahydrofuran (THF) was flowed as a column solvent at a flow rate of 1 mL / min to adjust the sample concentration to 0.05 mass% to 0.6 mass%. Measurement is performed by injecting 50 μL to 200 μL of a resin tetrahydrofuran sample solution. In the measurement of the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared by several kinds of monodisperse polystyrene standard samples and the number of counts. As a standard polystyrene sample for preparing a calibration curve, the molecular weight is 6 × 10 ² , 2.1 × 10 ² , 4 × 10 ² , 1.75 × 10 ⁴ , 1.1 × 10 ⁵ , 3.9 × 10 ^5. 8.6 × 10 ⁵ , 2 × 10 ⁶ , and 4.48 × 10 ⁶ polystyrene samples (Pressure Chemical Co. or Tosoh Corporation) are used, and at least about 10 standard polystyrene samples are preferably used. . An RI (refractive index) detector can be used as the detector.

  The method for synthesizing the polyester prepolymer is not particularly limited and may be appropriately selected depending on the intended purpose. The polycondensate of a polyol and a polycarboxylic acid, and the active hydrogen group-containing polyester resin may be combined with a polyisocyanate. Specifically, the polyol and the polycarboxylic acid are heated to 150 ° C. to 280 ° C. in the presence of a known esterification catalyst (titanium tetrabutoxide, dibutyltin oxide, etc.). In addition, a method of producing by appropriately reducing pressure as necessary, distilling water to obtain a hydroxyl group-containing polyester, and then synthesizing by reacting the hydroxyl group-containing polyester resin with the polyisocyanate at 40 ° C. to 140 ° C., etc. Is mentioned.

---- Polyol ----
The polyol is not particularly limited and may be appropriately selected depending on the intended purpose. For example, alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.), alkylene ether glycol (diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.), alicyclic diol (1,4-cyclohexanedimethanol, Hydrogenated bisphenol A, etc.), bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.), alkylene oxides of the above alicyclic diols (ethylene oxide, propylene oxide) Diol, butylene oxide, etc.) adducts, diols such as alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adducts of the above bisphenols; polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol) , Sorbitol, etc.) Trivalent or higher valent phenols (phenol novolak, cresol novolak, etc.), Trivalent or higher polyols such as alkylene oxide adducts of trivalent or higher polyphenols; Mixtures of diols and trivalent or higher polyols; Etc. These may be used individually by 1 type and may use 2 or more types together. Among these, the polyol is preferably the diol alone or a mixture of the diol and a small amount of the trivalent or higher polyol. Examples of the diol include alkylene glycols having 2 to 12 carbon atoms, alkylene oxide adducts of bisphenols (bisphenol A ethylene oxide 2 mol adduct, bisphenol A propylene oxide 2 mol adduct, bisphenol A propylene oxide 3 mol adduct, etc.) Is preferred.

  There is no restriction | limiting in particular as content in the isocyanate group containing polyester prepolymer of the said polyol, Although it can select suitably according to the objective, For example, 0.5 mass%-40 mass% are preferable, and 1 mass%- 30 mass% is more preferable, and 2 mass%-20 mass% is especially preferable. When the content is less than 0.5% by mass, the hot offset resistance deteriorates, and it may be difficult to achieve both the heat-resistant storage stability and the low-temperature fixability of the toner. When the content exceeds 40% by mass, Low temperature fixability may deteriorate.

---- Polycarboxylic acid ----
There is no restriction | limiting in particular as said polycarboxylic acid, According to the objective, it can select suitably, For example, alkylene dicarboxylic acid (succinic acid, adipic acid, sebacic acid, etc.); C4-C20 alkenylene dicarboxylic acid ( Maleic acid, fumaric acid, etc.); C8-20 aromatic dicarboxylic acids (terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, etc.); Trivalent or higher polycarboxylic acids (trimellitic acid, pyromellitic acid, etc.) 9-20 aromatic polycarboxylic acids, etc.), mixtures of dicarboxylic acids with trivalent or higher polycarboxylic acids, and the like. Any acid anhydride or lower alkyl ester selected from these polycarboxylic acids may be used. Examples of the lower alkyl ester include methyl ester, ethyl ester, isopropyl ester and the like. The mixing mass ratio (DIC: TC) between the dicarboxylic acid (DIC) and the trivalent or higher polycarboxylic acid (TC) is not particularly limited and may be appropriately selected depending on the intended purpose. : 0.01 to 10 is preferable, and 100: 0.01 to 1 is more preferable.

  The mixing ratio in the polycondensation reaction between the polyol and the polycarboxylic acid is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the hydroxyl group [OH] in the polyol and the polycarboxylic acid The equivalent ratio ([OH] / [COOH]) to the carboxyl group [COOH] in (PC) is preferably 2/1 to 1/1, more preferably 1.5 / 1 to 1/1, and 1.3 /1-1.02/1 is particularly preferable.

---- Polyisocyanate ----
The polyisocyanate is not particularly limited and may be appropriately selected depending on the intended purpose. For example, aliphatic polyisocyanate (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, octamethylene Diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, trimethylhexane diisocyanate, tetramethylhexane diisocyanate, etc .; alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); aromatic diisocyanates (tolylene diisocyanate, diphenylmethane) Diisocyanate, 1,5-naphthylene diisocyanate, diphenylene-4, '-Diisocyanate, 4,4'-diisocyanato-3,3'-dimethyldiphenyl, 3-methyldiphenylmethane-4,4'-diisocyanate, diphenyl ether-4,4'-diisocyanate, etc .; araliphatic diisocyanate (α, α , Α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanurates (tris-isocyanatoalkyl-isocyanurate, triisocyanatocycloalkyl-isocyanurate, etc.); these phenol derivatives; blocked with oximes, caprolactam, etc. And the like. These may be used alone or in combination of two or more.

  There is no restriction | limiting in particular as content in the said polyester prepolymer of the said polyisocyanate, Although it can select suitably according to the objective, 0.5 mass%-40 mass% are preferable, and 1 mass%-30 mass. % Is more preferable, and 2% by mass to 20% by mass is particularly preferable. When the content is less than 0.5% by mass, the hot offset resistance is deteriorated, and it may be difficult to achieve both heat-resistant storage stability and low-temperature fixability. Sexuality may worsen.

  The equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] of the polyisocyanate and the hydroxyl group [OH] of the active hydrogen group-containing polyester resin (in the case of a hydroxyl group-containing polyester resin) is not particularly limited, However, 5/1 to 1/1 is preferable, 4/1 to 1.2 / 1 is more preferable, and 3/1 to 1.5 / 1 is particularly preferable. When the equivalent ratio [NCO] / [OH] is less than 1/1, the offset resistance may be deteriorated, and when it exceeds 5/1, the low-temperature fixability may be deteriorated.

  In the case of reacting the polyisocyanate with the hydroxyl group-containing polyester resin, an organic solvent can be used as necessary. Examples of the organic solvent include aromatic solvents (toluene, xylene, etc.); ketones (acetone, acetone, Examples thereof include solvents inert to isocyanate groups such as methyl ethyl ketone, methyl isobutyl ketone, etc .; esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.); ethers (tetrahydrofuran, etc.).

--- Method for synthesizing modified polyester resin ---
The method for synthesizing the modified polyester resin is not particularly limited and may be appropriately selected depending on the intended purpose. For example, (1) dissolution or dissolution of a toner material containing a polymer capable of reacting with the active hydrogen group-containing compound. The dispersion may be synthesized by emulsifying or dispersing the dispersion together with the active hydrogen group-containing compound in an aqueous medium (aqueous phase), forming oil droplets, and subjecting both to an extension reaction or a crosslinking reaction in the aqueous medium. Well, (2) the solution or dispersion of the toner material is emulsified or dispersed in an aqueous medium to which the active hydrogen group-containing compound has been added in advance to form oil droplets. (3) After the toner material solution or dispersion is added and mixed in an aqueous medium, the active hydrogen group-containing compound is added to form oil droplets. The water It may be synthesized by elongation reaction or crosslinking reaction from particle interfaces in the medium. In the case of (3), a modified polyester resin is preferentially produced on the surface of the toner to be produced, and it becomes possible to provide a concentration gradient on the toner particles. The extension reaction or crosslinking reaction may be stopped by a reaction terminator (for example, a blocked monoamine such as diethylamine, dibutylamine, butylamine, laurylamine, ketimine compound, etc.) as necessary. Since the polyester coexisting with the crosslinking reaction or elongation reaction coexists, the toner exhibits good heat-resistant storage stability even when the glass transition temperature is lower than that of a conventional polyester toner.

  The number average molecular weight of the modified polyester resin is not particularly limited in the case of the urea-modified polyester resin, and can be appropriately selected according to the purpose, but is preferably 1,000 to 10,000, and preferably 1,500 to 60. , 00 is more preferable.

There is no restriction | limiting in particular as glass transition temperature (Tg) of the said modified polyester resin, Although it can select suitably according to the objective, 30 to 70 degreeC is preferable and 40 to 65 degreeC is more preferable. When the glass transition temperature (Tg) is less than 30 ° C., the heat-resistant storage stability of the toner may deteriorate, and when it exceeds 70 ° C., the low-temperature fixability may not be sufficient.
The glass transition temperature (Tg) can be measured by the following method using, for example, a TG-DSC system TAS-100 (manufactured by Rigaku Corporation).
First, about 10 mg of toner is placed in an aluminum sample container, and the sample container is placed on a holder unit and set in an electric furnace. After heating from room temperature to 150 ° C. at a rate of temperature increase of 10 ° C./min, the sample is left at 150 ° C. for 10 minutes, and the sample is cooled to room temperature and left for 10 minutes. Then, the DSC curve is measured with a differential scanning calorimeter (DSC) after heating to 150 ° C. at a temperature rising rate of 10 ° C./min in a nitrogen atmosphere. From the obtained DSC curve, using the analysis system in the TG-DSC system TAS-100 system, the glass transition temperature (Tg) is calculated from the contact point between the tangent line of the endothermic curve near the glass transition temperature (Tg) and the baseline. To do.

  The modified polyester resin is not particularly limited as long as it is a resin obtained by the synthesis method, and can be appropriately selected according to the purpose, but a urea-modified polyester resin is preferable.

---- Urea-modified polyester resin ---
The urea-modified polyester resin may contain a urethane bond in addition to the urea bond. In this case, the molar ratio of the urea bond to the urethane bond (urea bond / urethane bond) is not particularly limited and may be appropriately selected depending on the intended purpose. Preferably, 80/20 to 20/80 is more preferable, and 60/40 to 30/70 is particularly preferable. When the urea bond in the content molar ratio (urea bond / urethane bond) is less than 10, the hot offset resistance may be deteriorated.

  The urea-modified polyester resin is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include the resins described in (1) to (10).

(1) A polyester prepolymer obtained by reacting a polycondensate of bisphenol A ethylene oxide 2 mol adduct and isophthalic acid with isophorone diisocyanate and uread with isophorone diamine, bisphenol A ethylene oxide 2 mol adduct and isophthalic acid A resin containing a mixture with a polycondensate.

(2) A polyester prepolymer obtained by reacting a polycondensate of bisphenol A ethylene oxide 2-mole adduct and isophthalic acid with isophorone diisocyanate and uread with isophorone diamine, bisphenol A ethylene oxide 2-mole adduct and terephthalic acid A resin containing a mixture with a polycondensate.

(3) A bisphenol A ethylene oxide 2-mole adduct / bisphenol A propylene oxide 2-mole adduct and a polyester prepolymer obtained by reacting a polycondensate of terephthalic acid with isophorone diisocyanate and urethanized with isophorone diamine, and bisphenol A ethylene A resin comprising a mixture of an oxide 2 mol adduct / bisphenol A propylene oxide 2 mol adduct and a polycondensate of terephthalic acid.

(4) A polyester prepolymer obtained by reacting a polycondensate of bisphenol A ethylene oxide 2 mol adduct / bisphenol A propylene oxide 2 mol adduct and terephthalic acid with isophorone diisocyanate, and bisphenol A propylene A resin comprising a mixture of an oxide 2 mol adduct and a polycondensate of terephthalic acid.

(5) A polyester prepolymer obtained by reacting a polycondensate of bisphenol A ethylene oxide 2-mole adduct and terephthalic acid with isophorone diisocyanate and uread with hexamethylenediamine, bisphenol A ethylene oxide 2-mole adduct, and terephthalate A resin containing a mixture with an acid polycondensate.

(6) Polyester prepolymer obtained by reacting a polycondensate of bisphenol A ethylene oxide 2 mol adduct and terephthalic acid with isophorone diisocyanate and uread with hexamethylenediamine, and bisphenol A ethylene oxide 2 mol adduct / bisphenol A A resin comprising a mixture of propylene oxide 2 mol adduct and a polycondensate of terephthalic acid.

(7) A polyester prepolymer obtained by reacting a polycondensate of bisphenol A ethylene oxide 2 mol adduct and terephthalic acid with isophorone diisocyanate with urea and ethylenediamine 2 mol adduct and terephthalic acid A resin containing a mixture with a condensate.

(8) Polyester prepolymer obtained by reacting a polycondensate of bisphenol A ethylene oxide 2 mol adduct and isophthalic acid with diphenylmethane diisocyanate, and urethanized with hexamethylenediamine, bisphenol A ethylene oxide 2 mol adduct and isophthalic acid A resin containing a mixture with a polycondensate.

(9) A polyester prepolymer obtained by reacting a polycondensate of bisphenol A ethylene oxide 2 mol adduct / bisphenol A propylene oxide 2 mol adduct and terephthalic acid / dodecenyl succinic anhydride with diphenylmethane diisocyanate was uread with hexamethylenediamine. And a mixture of bisphenol A ethylene oxide 2-mole adduct / bisphenol A propylene oxide 2-mole adduct and terephthalic acid polycondensate.

(10) A polyester prepolymer obtained by reacting a polycondensate of bisphenol A ethylene oxide 2 mol adduct and isophthalic acid with toluene diisocyanate and uread with hexamethylenediamine, bisphenol A ethylene oxide 2 mol adduct and isophthalic acid A resin containing a mixture with a polycondensate.

  The method for synthesizing the urea-modified polyester resin is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the urea-modified polyester resin can be produced by a one-shot method, specifically, the active hydrogen group-containing compound. And the like, and an isocyanate group-containing polyester prepolymer as a polymer that can react with the active hydrogen group-containing compound is subjected to an elongation reaction or a crosslinking reaction in an aqueous medium. The extension reaction or the crosslinking reaction is not particularly limited, and can be appropriately selected according to the combination of the polymer capable of reacting with the active hydrogen group-containing compound and the active hydrogen group-containing compound. 10 minutes to 40 hours are preferable, and 2 hours to 24 hours are more preferable.

  In the synthesis of the urea-modified polyester resin, the mixing ratio of the isocyanate group-containing polyester prepolymer and the amines is not particularly limited and may be appropriately selected depending on the intended purpose. The mixing equivalent ratio [NCO] / [NHx] of the isocyanate group [NCO] of the above and the amino group [NHx] in the amines is preferably 1/3 to 3/1, and 1/2 to 2/1. More preferred is 1 / 1.5 to 1.5 / 1. If the mixing equivalent ratio ([NCO] / [NHx]) is less than 1/3, the low-temperature fixability may be reduced. If it exceeds 3/1, the molecular weight of the urea-modified polyester resin is reduced. Hot offset resistance may deteriorate.

  In the synthesis of the urea-modified polyester resin, when the isocyanate group-containing polyester prepolymer and the amines are reacted, an organic solvent can be used as necessary. Examples of the solvent include aromatic solvents. (Toluene, xylene, etc.); Ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); Esters (ethyl acetate, etc.); Amides (dimethylformamide, dimethylacetamide, etc.); Ethers (tetrahydrofuran, etc.) Examples of the solvent are inert to the solvent.

<< Colorant >>
The colorant is not particularly limited and may be appropriately selected depending on the purpose, for example, known dyes and pigments. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G G), cadmium yellow, yellow iron oxide, ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment red, pigment yellow L, benzidine yellow (G, GR), Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Lead Red, Lead Red, Cadmium Red, Cadmium Mercury Red , Antimon Zhu, Permanent Red 4 , Para Red, Faise Red, Parachlor Ortho Nitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B , Brilliant Scarlet G, Risor Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroo , Oil Red, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal-free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), Indigo, Ultramarine Blue, Bitumen, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green , Chromium oxide, pyridian, emerald green, pigment green B, naphthol green B, green gold, Acid green lake, malachite green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, lithopone, and the like. These may be used alone or in combination of two or more.

  There is no restriction | limiting in particular as content with respect to the said toner of the said coloring agent, Although it can select suitably according to the objective, 1 mass%-15 mass% are preferable, and 3 mass%-10 mass% are more preferable. When the content is less than 1% by mass, a reduction in the coloring power of the toner is observed. When the content exceeds 15% by mass, poor dispersion of the pigment in the toner, a reduction in the coloring power, and the electrical characteristics of the toner. May cause a drop.

  The colorant can also be used as a master batch combined with the resin. There is no restriction | limiting in particular as said resin, According to the objective, it can select suitably, For example, a polyester resin, styrene or its substituted polymer (poly p-chlorostyrene, polyvinyl toluene, etc.), styrene-based copolymer Copolymer (styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer) Polymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene- α-Chloromethyl methacrylate copolymer, styrene-acrylonitrile Copolymer, Styrene-vinyl methyl ketone copolymer, Styrene-butadiene copolymer, Styrene-isoprene copolymer, Styrene-acrylonitrile-indene copolymer, Styrene-maleic acid copolymer, Styrene-maleic acid ester copolymer Polymers), polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride resin, polyvinyl acetate resin, polyethylene resin, polypropylene resin, epoxy resin, epoxy polyol resin, polyurethane resin, polyamide resin, polyvinyl butyral resin, polyacrylic acid resin Rosin, modified rosin, terpene resin, aliphatic hydrocarbon resin, alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax, and the like. These may be used individually by 1 type and may use 2 or more types together.

  There is no restriction | limiting in particular as a manufacturing method of the said masterbatch, According to the objective, it can select suitably, For example, mixing thru | or kneading | mixing the resin for the said masterbatch, the said coloring agent, an organic solvent, etc. with high shear force. And a manufacturing method. The organic solvent is added to enhance the interaction between the colorant and the binder resin. In addition, the other production method of the masterbatch is not particularly limited and can be appropriately selected according to the purpose, but the wet cake of the colorant can be used as it is and does not need to be dried. An aqueous paste containing water of a colorant called a flushing method is mixed or kneaded together with the binder resin and an organic solvent, the colorant is transferred to the resin side, and water and organic solvent components are removed to produce the paste. preferable. When mixing or kneading, a high shear dispersion device such as a three roll mill is preferably used.

-Release agent-
The release agent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include plant waxes (carnauba wax, cotton wax, wood wax, rice wax, etc.), animal waxes (honey beeswax, lanolin). Waxes and waxes such as mineral wax (such as ozokerite and cercin), petroleum wax (such as paraffin, microcrystalline, and petrolatum); synthetic hydrocarbon wax (such as Fischer-Tropsch wax and polyethylene wax), and synthetic wax ( Esters, ketones, ethers, etc.) other than natural waxes; 1,2-hydroxystearic amide, stearic amide, phthalic anhydride, fatty acid amides such as chlorinated hydrocarbons; low molecular weight crystalline polymers Some polymethacrylate n-stearyl, polymethacrylate n Poly homopolymers or copolymers of acrylate lauryl etc. - crystalline polymer having a long chain alkyl group in the side chain of (acrylic acid n- stearyl ethyl methacrylate copolymer, etc.) and the like; and the like. Among these, since it can act effectively as a release agent between the fixing roller and the toner interface, high temperature offset resistance can be improved without applying a release agent such as oil to the fixing roller. A wax having a melting point of 50 ° C. to 120 ° C. is preferable because it can be used.

  There is no restriction | limiting in particular as melting | fusing point of the said mold release agent, Although it can select suitably according to the objective, 50 to 120 degreeC is preferable and 60 to 90 degreeC is more preferable. If the melting point is less than 50 ° C., the wax may adversely affect storage stability. If the melting point exceeds 120 ° C., cold offset may easily occur during fixing at a low temperature. The melting point of the release agent is determined by measuring the maximum endothermic peak using a differential scanning calorimeter (TG-DSC system, TAS-100, manufactured by Rigaku Corporation).

  The melt viscosity of the release agent is not particularly limited and may be appropriately selected depending on the intended purpose. However, the measured value at a temperature 20 ° C. higher than the melting point of the wax is preferably 5 cps to 1,000 cps, 10 cps to 100 cps is more preferable. If the melt viscosity is less than 5 cps, the releasability may be lowered, and if it exceeds 1,000 cps, the effect of improving hot offset resistance and low-temperature fixability may not be obtained.

  There is no restriction | limiting in particular as content in the said toner of the said mold release agent, Although it can select suitably according to the objective, 40 mass% or less is preferable and 3 mass%-30 mass% are more preferable. When the content exceeds 40% by mass, the fluidity of the toner may be deteriorated.

  The release agent is preferably present in a dispersed state in the toner base particles, and for this purpose, the release agent and the binder resin are preferably incompatible with each other. The method for finely dispersing the release agent in the toner base particles is not particularly limited and may be appropriately selected depending on the purpose. For example, the release agent is dispersed by applying a kneading shear force during toner production. The method etc. are mentioned.

  The dispersion state of the release agent can be confirmed by observing a thin film slice of toner particles with a transmission electron microscope (TEM). The dispersion diameter of the release agent is preferably small, but if it is too small, there are cases where bleeding during fixing is insufficient. Therefore, if the release agent can be confirmed at a magnification of 10,000, the release agent is present in a dispersed state. If the release agent cannot be confirmed at a magnification of 10,000, even if finely dispersed, exudation at the time of fixing becomes insufficient.

<Other ingredients>
The other components are not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include layered inorganic minerals, magnetic materials, cleaning improvers, fluidity improvers, charge control agents, and the like. .

-Layered inorganic mineral-
The modified layered inorganic mineral is not particularly limited as long as it is an inorganic mineral in which layers having a thickness of several nm are laminated, and can be appropriately selected according to the purpose. For example, montmorillonite, bentonite, hectorite, attapulgite , Sepiolite, or a mixture thereof. These may be used alone or in combination of two or more. Among these, a modified layered inorganic mineral is preferable because it can be modified when the toner is granulated, has a charge control function, and is excellent in low-temperature fixing, and a layered inorganic mineral having a montmorillonite-based basic crystal structure is an organic cation. Organic modified montmorillonite and bentonite are particularly preferred from the viewpoint that the modified layered inorganic mineral modified with the above is more preferable, and the viscosity can be easily adjusted without affecting the toner characteristics.

  The modified layered inorganic compound preferably modifies at least part of the layered inorganic mineral with organic ions. By modifying at least a part of the layered inorganic mineral with organic ions, the layer has an appropriate hydrophobicity, the oil phase containing the toner composition and / or the toner composition precursor has a non-Newtonian viscosity, Can be modified.

  There is no restriction | limiting in particular as content in the said toner base particle of the said modified | denatured layered inorganic mineral, Although it can select suitably according to the objective, 0.05 mass%-5 mass% are preferable.

-Magnetic material-
There is no restriction | limiting in particular as said magnetic material, According to the objective, it can select suitably, For example, iron powder, magnetite, a ferrite, etc. are mentioned. Among these, white is preferable in terms of color tone.

-Cleaning improver-
The cleaning property improving agent is not particularly limited as long as it is an agent added to the toner in order to remove the developer after transfer remaining on the photosensitive member or the primary transfer medium, and is appropriately selected according to the purpose. Examples thereof include fatty acid metal salts such as zinc stearate, calcium stearate and stearic acid, polymer fine particles produced by soap-free emulsion polymerization such as polymethyl methacrylate fine particles and polystyrene fine particles. There is no restriction | limiting in particular as a volume average particle diameter of the said polymer fine particle, Although it can select suitably according to the objective, A thing with a comparatively narrow particle size distribution is preferable, and 0.01 micrometer-1 micrometer are more preferable.

-Fluidity improver-
The fluidity improver is an agent that performs surface treatment to increase hydrophobicity and prevents deterioration of flow characteristics and charging characteristics even under high humidity. For example, a silane coupling agent, a silylating agent, Examples thereof include a silane coupling agent having a fluoroalkyl group, an organic titanate coupling agent, an aluminum coupling agent, silicone oil, and modified silicone oil. The fluidity improver may be surface-treated with silica, titanium oxide or the like, and in this case, it is preferably used as hydrophobic silica or hydrophobic titanium oxide or the like.

-Charge control agent-
The charge control agent is not particularly limited and may be appropriately selected depending on the intended purpose.For example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, Alkoxy amine, quaternary ammonium salt (including fluorine-modified quaternary ammonium salt), alkylamide, phosphorus simple substance or compound, tungsten simple substance or compound, fluorine activator, salicylic acid metal salt, salicylic acid derivative metal salt, copper Examples thereof include phthalocyanine, perylene, quinacridone, azo pigments, and other polymer compounds having a functional group such as a sulfonic acid group, a carboxyl group, and a quaternary ammonium salt.

  Trade names of the charge control agents include, for example, Nigrosine dye Bontron 03, quaternary ammonium salt Bontron P-51, metal-containing azo dye Bontron S-34, and oxynaphthoic acid metal complex E-82. , Salicylic acid metal complex E-84, phenol condensate E-89 (above, manufactured by Orient Chemical Co., Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical) Kogyo Co., Ltd.), quaternary ammonium salt copy charge PSY VP2038, triphenylmethane derivative copy blue PR, quaternary ammonium salt copy charge NEG VP2036, NX VP434 (above, Hoechst), LRA-901 LR-147 (manufactured by Nippon Carlit Co., Ltd.) and the like.

  The content of the charge control agent is not particularly limited and may be appropriately selected depending on the purpose, but is preferably 0.1 parts by mass to 10 parts by mass with respect to 100 parts by mass of the binder resin. 0.2 mass part-5 mass parts are more preferable. When the content exceeds 10 parts by mass, the chargeability of the toner is too large, the effect of the main charge control agent is reduced, the electrostatic attraction force with the developing roller is increased, and the flowability of the developer is reduced. The image density may be reduced. The charge control agent may be melt-kneaded with a masterbatch and resin and then dissolved and dispersed, or may be added when directly dissolving or dispersing in the organic solvent, and is fixed after the toner particles are produced on the toner surface. You may make it.

<Toner production method>
There is no restriction | limiting in particular as a manufacturing method of the said toner, According to the objective, it can select suitably, For example, the method of manufacturing by the pulverization method, the method of manufacturing by the polymerization method, etc. are mentioned. Among these, the method of producing by a polymerization method is preferable in that the toner can be reduced in particle size.

<< Crushing method >>
The pulverization method is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a method of producing toner base particles by melting or kneading a toner material and pulverizing or classifying it. For the purpose of setting the average circularity of the toner to 0.97 to 1.0, the shape may be controlled by applying a mechanical impact force to the obtained toner base particles. In this case, examples of a method for applying the mechanical impact force include a method using a device such as a hybridizer or mechanofusion. Further, the toner base particles produced in this manner are treated with an external additive to obtain a toner.

<< Polymerization method >>
There is no restriction | limiting in particular as said polymerization method, According to the objective, it can select suitably, For example, suspension polymerization method, solution suspension polymerization method, emulsion polymerization aggregation method, etc. are mentioned. Among these, the emulsion polymerization aggregation method is preferable, and the dissolution suspension method is more preferable.

-Emulsion polymerization aggregation method-
The emulsion polymerization aggregation method is not particularly limited and may be appropriately selected depending on the intended purpose, but preferably includes an aggregation step, a fusion step, a washing or drying step, and an external addition treatment step. Includes a method of producing toner base particles by dispersing or emulsifying an oil phase containing a toner composition or a toner composition precursor in an aqueous phase (aqueous medium) and granulating it. Further, the toner of the present invention can be obtained by treating the toner base particles thus produced with an external additive.

-Aggregation process-
In the aggregation step, a resin particle dispersion prepared by emulsion polymerization, a layered inorganic mineral modified at least partially with organic ions, a colorant dispersion, and, if necessary, a release agent dispersion are mixed to form aggregated particles. This is a step of preparing a dispersion. Aggregated particles in the aggregated particle dispersion are aggregated by heteroaggregation. For the purpose of stabilizing the aggregated particles and controlling the particle size / particle size distribution, an ionic surfactant having a polarity different from that of the aggregated particles or a compound having a monovalent or higher charge such as a metal salt may be added. it can.

  In the aggregating step, the emulsifying power of the emulsifier can be adjusted by pH to generate agglomeration, thereby adjusting agglomerated particles. At the same time, an aggregating agent may be added in order to obtain agglomerated particles having a narrower particle size distribution stably and rapidly. The flocculant is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably a compound having a monovalent or higher charge, specifically, a water-soluble surfactant such as a nonionic surfactant. Agents, acids such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid, oxalic acid, metal salts of inorganic acids such as magnesium chloride, sodium chloride, aluminum sulfate, calcium sulfate, ammonium sulfate, aluminum nitrate, silver nitrate, copper sulfate, sodium carbonate, acetic acid Aliphatic acids such as sodium, potassium formate, sodium oxalate, sodium phthalate, potassium salicylate, metal salts of aromatic acids, metal salts of phenols such as sodium phenolate, metal salts of amino acids, triethanolamine hydrochloride, Examples thereof include inorganic acid salts of aliphatic and aromatic amines such as aniline hydrochloride. Among these, a metal salt of an inorganic acid is preferable because it is excellent in stability of the aggregated particles, stability of the aggregating agent with respect to heat and time, and removal during washing. The amount of the flocculant added is not particularly limited, and varies depending on the valence of the charge. The mass% or less is preferable. The addition amount is preferably smaller, and a compound having a higher valence is advantageous in that the addition amount can be reduced.

-Fusion process-
The fusing step is a step of forming the toner base particles by heat fusing the aggregated particle dispersion. In the previous stage of the fusing step, there can be provided an attaching step in which other fine particle dispersion is added to and mixed with the aggregated particle dispersion to uniformly attach the fine particles to the surface of the aggregated particles to form adhered particles. In order to strengthen the adhesion of the layered inorganic mineral modified at least partly with organic ions, the layered inorganic mineral modified at least partly with organic ions is adhered, and other fine particle dispersions are added and mixed. Thus, it is possible to provide an attachment step in which fine particles are uniformly attached to the surface of the aggregated particles to form attached particles. These adhered particles are formed by heteroaggregation or the like. This adhered particle dispersion is also fused by heating to a temperature equal to or higher than the glass transition point of the resin particles to form fused particles. The fused particles are present as a colored fused particle dispersion in the aqueous medium, and at the same time, the fused particles are removed from the aqueous medium in the washing step, and at the same time, impurities mixed in the respective steps are removed or dried. A toner as a powder is obtained.

-Cleaning process-
The washing step involves adding several times the amount of acidic or basic water to the fused particles, stirring, and then adding several times the amount of acidic or basic water to the solid content obtained by filtration. In addition, the mixture is stirred and then filtered. This is repeated several times until the pH of the filtrate reaches about 7, and a colored toner is obtained.

--- Drying process--
In the drying step, the toner obtained in the washing step is dried at a temperature lower than the glass transition point. At this time, if necessary, dry air may be circulated or heated under vacuum conditions.

-Dissolution suspension method-
The dissolution suspension method is not particularly limited and may be appropriately selected depending on the intended purpose, but a method of production by aqueous granulation is preferable, an oil phase preparation step, an aqueous phase preparation step, an emulsification or dispersion step, The method of manufacturing by including a solvent removal process, a washing | cleaning thru | or drying process, and an external additive process process is more preferable.

  Specific examples of the dissolution suspension method are not particularly limited and may be appropriately selected depending on the intended purpose. At least the binder resin and the colorant are dissolved or dispersed in an organic solvent, and the dissolution or suspension is performed. A method of producing a toner by adding a dispersion base in an aqueous phase to emulsify or disperse the toner base particles obtained by removing the organic solvent from the emulsified or dispersed liquid and an external additive is preferable. .

  Among the dissolution suspension methods, an ester extension method is preferred, and specific examples of the ester extension method include at least the active hydrogen group-containing compound, a polymer that can react with the active hydrogen group-containing compound, the binder resin, And the coloring agent is dissolved or dispersed in an organic solvent, the dissolved or dispersed material is added to an aqueous phase and emulsified or dispersed, and the active hydrogen group-containing compound and the active hydrogen group-containing are contained in the emulsified or dispersed liquid. A method of producing a toner by mixing a toner base particle obtained by extending or cross-linking a polymer capable of reacting with a compound and removing the organic solvent from the emulsion or dispersion, and an external additive is preferable. .

-Oil phase preparation process-
The oil phase preparation step is a step of preparing an oil phase (solution or dispersion of toner material) by dissolving or dispersing a toner material containing at least the binder resin and the colorant in an organic solvent. Further, components other than the polymer capable of reacting with the active hydrogen group-containing compound in the toner material may be added and mixed in an aqueous medium in the preparation of an aqueous phase described later, or a solution or dispersion of the toner material. May be added to the aqueous medium together with the dissolved or dispersed liquid.
There is no restriction | limiting in particular as said organic solvent, Although it can select suitably according to the objective, The organic solvent whose boiling point is less than 150 degreeC is preferable at the point which solvent removal is easy. The organic solvent having a boiling point of less than 150 ° C. is not particularly limited and may be appropriately selected depending on the intended purpose. For example, toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1 1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, and the like. These may be used individually by 1 type and may use 2 or more types together. Among these, ethyl acetate, toluene, xylene, benzene, methylene chloride, 1,2-dichloroethane, chloroform, carbon tetrachloride and the like are preferable, and ethyl acetate is particularly preferable.
There is no restriction | limiting in particular as the usage-amount of the said organic solvent, Although it can select suitably according to the objective, 40 mass parts-300 mass parts are preferable with respect to 100 mass parts of said toner materials, and 60 mass parts-140 mass parts. Part is more preferable, and 80 parts by mass to 120 parts by mass is particularly preferable.

--Aqueous phase preparation process--
The aqueous phase preparation step is a step of preparing an aqueous phase (aqueous medium). There is no restriction | limiting in particular as said aqueous phase, According to the objective, it can select suitably, For example, water, the solvent miscible with water, these mixtures, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, water is preferable. Examples of the miscible solvent include alcohol (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methylcellosolv (registered trademark), etc.), lower ketones (acetone, methyl ethyl ketone, etc.), etc. Is mentioned.

--Emulsification or dispersion process--
The emulsification or dispersion step is a step of obtaining an emulsification or dispersion by dispersing the oil phase in the aqueous phase. The toner material is not necessarily mixed when the particles are formed in the aqueous phase, and may be added after the particles are formed. For example, the particles containing no colorant may be formed. Thereafter, a coloring agent can be added by a known dyeing method.
There is no restriction | limiting in particular as the usage-amount of the water phase with respect to 100 mass parts of said toner materials, Although it can select suitably according to the objective, 50 mass parts-2,000 mass parts are preferable, 100 mass parts-1, 000 parts by mass is more preferable. If the amount used is less than 50 parts by mass, the toner material may be poorly dispersed, and toner particles having a predetermined particle size may not be obtained. If it exceeds 2,000 parts by mass, it is not economical. There is. Moreover, a dispersing agent can also be used as needed. It is preferable to use a dispersant because the particle size distribution becomes sharp and the dispersion is stable.

  The dispersant used in the emulsification or dispersion step is not particularly limited and can be appropriately selected depending on the purpose. For example, an anionic surfactant, a cationic surfactant, a nonionic surfactant, Amphoteric surfactants, anionic surfactants having fluoroalkyl groups, cationic surfactants having fluoroalkyl groups, inorganic compounds (tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, hydroxyapatite, etc.), fine particle polymers (MMA polymer fine particle 1 μm, MMA polymer fine particle 3 μm, styrene fine particle 0.5 μm, styrene fine particle 2 μm, styrene-acrylonitrile fine particle polymer 1 μm, etc.). Among these, a surfactant having a fluoroalkyl group is preferable in that the effect can be obtained in a very small amount.

  There is no restriction | limiting in particular as content of the said dispersing agent, Although it can select suitably according to the objective, In the case of a resin fine particle dispersion, 0.01 mass%-1 mass% are preferable, 0.02 mass% -0.5 mass% is more preferable, and 0.1 mass% -0.2 mass% is especially preferable. When the content is less than 0.01% by mass, aggregation may occur in a state where the pH of the emulsification or dispersion is not sufficiently basic. There is no restriction | limiting in particular as content of the said dispersing agent, Although it can select suitably according to the objective, In the case of a colorant dispersion or a mold release agent dispersion, 0.01 mass%-10 mass% are preferable. 0.1 mass% to 5 mass% is more preferable, and 0.5 mass% to 0.2 mass% is particularly preferable. When the content is less than 0.01% by mass, the stability between the particles is different at the time of agglomeration, so that the release of specific particles may occur. When the content exceeds 10% by mass, the particle size distribution of the particles becomes wide. In some cases, it may be difficult to control the particle size.

  As a trade name of the dispersing agent, for example, Surflon S-111, S-112, S-113, S-121 (above, manufactured by Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC -129, FC-135 (above, manufactured by Sumitomo 3M Co., Ltd.), Unidyne DS-101, DS-102, DS-202 (above, manufactured by Daikin Industries, Ltd.), MegaFuck F-l0, F-l20, F- 113, F-150, F-191, F-812, F-824, F-833 (above, manufactured by DIC Corporation), Xtop EF-102, 103, 104, 105, 112, 123A, 123B, 132, 306A, 501, 201, 204 (above, manufactured by Tochem Products Co., Ltd.), Fantent F-100, F-300, F150 (above, Neos Inc.) ), SGP, SGP-3G (above, manufactured by Soken Co., Ltd.), PB-200H (manufactured by Kao Corporation), Technopolymer SB (manufactured by Sekisui Plastics Co., Ltd.), Micropearl (manufactured by Sekisui Fine Chemical Co., Ltd.) Is mentioned.

  When the dispersant is used, the dispersant may remain on the surface of the toner particles. However, it is preferable to remove it after the reaction in terms of the charged surface of the toner. Furthermore, it is preferable to use a solvent that can dissolve the modified polyester after the reaction of the polyester prepolymer, in that the particle size distribution becomes sharp and the viscosity of the toner material is lowered. The solvent is preferably a volatile solvent having a boiling point of less than 100 ° C. in terms of easy removal. For example, toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1 , 2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, methanol, and other water-miscible solvents. These may be used individually by 1 type and may use 2 or more types together. Among these, aromatic solvents such as toluene and xylene, and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform, and carbon tetrachloride are preferable.

  When the dispersant is used, it is preferable to use a dispersion stabilizer. When a polymeric protective colloid is used as the dispersion stabilizer, there is no particular limitation as long as it is a substance that stabilizes the dispersed droplets with organic fine particles insoluble in water, etc., and it is appropriately selected according to the purpose. For example, acids such as acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride; β-hydroxyethyl acrylate, methacrylic acid Β-hydroxyethyl acid, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, γ-hydroxypropyl methacrylate, 3-chloro-2-hydroxypropyl acrylate, methacrylic acid 3 -Chloro-2-hydroxypropyl, diethylene glycol monoacrylate, di (Meth) acrylic monomers containing hydroxyl groups such as ethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate, N-methylolacrylamide, N-methylolmethacrylamide; vinyl methyl ether, vinylethyl Ethers such as ether and vinylpropyl ether or ethers of vinyl alcohol; esters of vinyl alcohol such as vinyl acetate, vinyl propionate and vinyl butyrate with a carboxyl group-containing compound; acrylamide, methacrylamide, diacetone acrylamide or These methylol compounds; acid chlorides such as acrylic acid chloride and methacrylic acid chloride; vinylpyridine, vinylpyrrolidone, vinylimidazole, ethyleneimine, etc. Homopolymers or copolymers such as compounds having a nitrogen atom or a heterocyclic ring thereof; polyoxyethylene, polyoxypropylene, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, Polyoxyethylenes such as polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene nonyl phenyl ester; celluloses such as methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose; It is done.

  When an acid such as calcium phosphate salt or an alkali-soluble compound is used as the dispersion stabilizer, the calcium phosphate salt is dissolved from the fine particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and washing with water. It is preferable to remove. The removal of the calcium phosphate salt may be performed by other operations such as degradation with an enzyme.

  The disperser used in the emulsification or dispersion step is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a low-speed shear disperser, a high-speed shear disperser, a friction disperser, a high pressure Examples thereof include a jet disperser and an ultrasonic disperser. Among these, a high-speed shearing disperser is preferable in that the particle diameter of the dispersion (oil droplets) can be controlled to 2 μm to 20 μm. When the high-speed shearing disperser is used, conditions such as the number of rotations, the dispersion time, and the dispersion temperature can be appropriately selected according to the purpose. There is no restriction | limiting in particular as said rotation speed, Although it can select suitably according to the objective, 1,000 rpm-30,000 rpm are preferable, and 5,000 rpm-20,000 rpm are more preferable. There is no restriction | limiting in particular as said dispersion | distribution time, Although it can select suitably according to the objective, In the case of a batch system, 0.1 minute-5 minutes are preferable. There is no restriction | limiting in particular as said dispersion | distribution temperature, Although it can select suitably according to the objective, 0 degreeC-150 degreeC is preferable under pressure, and 40 degreeC-98 degreeC is more preferable. In general, dispersion is easier when the dispersion temperature is higher.

-Solvent removal process-
The solvent removal step is a step of removing the organic solvent from the emulsion or dispersion (dispersion liquid such as an emulsion slurry). The method for removing the organic solvent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a method of gradually elevating the temperature of the entire reaction system to evaporate the organic solvent in the oil droplets, dispersion Examples include a method of removing the organic solvent in the oil droplets by spraying (spray dryer, belt dryer, rotary kiln, etc.) the liquid in a dry atmosphere (gas heated with air, nitrogen, carbon dioxide, combustion gas, etc.). By this method, the desired quality can be sufficiently obtained in a short time. When the organic solvent is removed, toner base particles are formed.

--Washing or drying process--
The washing or drying step is a step of washing or drying the toner base particles. The toner base particles may be further classified. The classification may be performed by removing fine particle portions in a liquid by a cyclone, a decanter, centrifugation, or the like, or may be performed after drying. The obtained unnecessary fine particles or coarse particles can be used again for forming fine particles. At that time, fine particles or coarse particles may be in a wet state.

--External additive treatment process--
The external additive processing step is a step of mixing and processing the toner base particles after drying and the external additive containing the coalescing particles satisfying specific parameters defined in the present invention. The toner of the present invention can be obtained by mixing the toner base particles and the external additive. There is no restriction | limiting in particular as an apparatus used for the said mixing, Although it can select suitably according to the objective, Henschel mixer (made by Nippon Coke Industries Co., Ltd.) is preferable. A mechanical impact force may be applied in order to prevent the particles such as the external additive from being detached from the surface of the toner base particles. The method for applying the mechanical impact force is not particularly limited and can be appropriately selected depending on the purpose. For example, a method for applying the impact force to the mixture using blades rotating at high speed, For example, a method may be used in which the mixture is charged and accelerated to cause the particles or particles to collide with an appropriate collision plate. There is no restriction | limiting in particular as an apparatus used for the said method, According to the objective, it can select suitably, For example, remodeling and grind | pulverizing an Ong mill (made by Hosokawa Micron Corporation) and an I type mill (made by Nippon Pneumatic Co., Ltd.) Examples include an apparatus in which the air pressure is lowered, a hybridization system (manufactured by Nara Machinery Co., Ltd.), a kryptron system (manufactured by Kawasaki Heavy Industries, Ltd.), and an automatic mortar.

<< Toner Characteristics >>
The ratio (Dw / Dn) between the weight average particle diameter (Dw) and the number average particle diameter (Dn) in the toner is not particularly limited and may be appropriately selected depending on the intended purpose. Is preferable, and 1.00-1.30 is more preferable. When the ratio (Dw / Dn) is less than 1.00, in the case of a two-component developer, the toner is fused to the surface of the carrier during long-term agitation in the developing device, and the chargeability of the carrier is deteriorated or the cleaning property is deteriorated. In the case of a one-component developer, toner filming on the developing roller and toner fusion to a member such as a blade may be likely to occur because the toner is thinned. When the ratio (Dw / Dn) exceeds 1.30, it becomes difficult to obtain a high-resolution and high-quality image, and when the balance of the toner in the developer is performed, the toner particle diameter varies. May grow.

  The average circularity of the toner is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.94 to 0.99. If the average circularity is less than 0.94, the image uniformity during development deteriorates, and the toner transfer efficiency from the electrostatic latent image bearing member to the intermediate transfer member or from the intermediate transfer member to the recording material decreases and becomes uniform. Transfer may not be obtained. The toner is prepared by emulsification in an aqueous medium, and is particularly effective for reducing the particle size of a color toner and obtaining a shape having an average circularity in the above range. The average circularity was measured using a flow particle image analyzer (FPIA-2000, manufactured by Sysmex Corporation). In a predetermined container, 100 mL to 150 mL of water from which impure solids were removed in advance was added, and 0.1 mL to 0.5 mL of a surfactant was added as a dispersant, and about 0.1 g to 9.5 g of a measurement sample was further added. . The suspension in which the sample is dispersed is subjected to dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the concentration and dispersion of the toner are adjusted to 3,000 / μL to 10,000 / μL. It was measured.

The weight average particle diameter of the toner used in the two-component developer of the present invention is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 3.0 μm to 9.0 μm, and preferably 3.0 μm to 6 0.0 μm is more preferable.
The weight average particle diameter can be measured using, for example, Coulter Multisizer II (manufactured by Coulter Counter).

<Method for producing developer>
The method for producing the developer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a method for producing the developer by mixing the carrier and the toner and stirring the mixture with a turbuler mixer. Is mentioned.

<Replenishment developer>
The replenishment developer includes the carrier and the toner. Further, the replenishment developer can be applied to an image forming apparatus that forms an image while discharging excess developer in the developing device. Further, the developing device using the replenishment developer can obtain a stable image quality for a very long time. That is, the image forming apparatus using the replenishment developer replaces the deteriorated carrier in the development apparatus and the undegraded carrier in the replenishment developer, and keeps the charge amount stable for a long period of time. Therefore, a stable image can be obtained. This method is particularly effective when printing a large image area. Deterioration at the time of printing a large image area is mainly due to a decrease in carrier charging ability due to toner spent on the carrier. However, using this method, the amount of carrier replenishment increases when the image area is large. The frequency with which the changed carriers are replaced increases.
There is no restriction | limiting in particular as content of the carrier in the said developer for replenishment, Although it can select suitably according to the objective, 3 to 30 mass% is preferable.
The mixing ratio of the replenishment developer is preferably 2 to 50 parts by mass, more preferably 5 to 12 parts by mass of toner with respect to 1 part by mass of the carrier. When the amount of the toner is less than 2 parts by mass, the amount of replenishment carrier is excessive, the carrier is excessively supplied, and the carrier concentration in the developing device becomes too high. Further, when the charge amount of the toner increases, the developing ability decreases and the image density decreases. On the other hand, when the amount of the toner exceeds 50 parts by mass, the carrier ratio in the replenishment developer decreases, so that the replacement of carriers in the image forming apparatus decreases, and the effect on carrier deterioration may not be expected.

<Developing device>
The developing device includes the two-component developer of the present invention, and appropriately has other structures as necessary. Preferably, the developer is filled in a storage container whose shape is easily deformed, and has a developer replenishing device that sucks the replenishing developer with a suction pump and supplies the developer to the developing device.

FIG. 2 is a diagram illustrating an example of a developing device according to the present invention. A developing device 40 disposed opposite to the photoreceptor 20 as an electrostatic latent image carrier includes a developing sleeve 41 as a developer carrier, a developer accommodating member 42, a doctor blade 43 as a regulating member, and a support case. 44 etc.
To a support case 44 having an opening on the side of the photoconductor 20, a toner hopper 45 serving as a toner storage unit that stores the toner 21 is joined. A developer containing portion 46 containing the toner 21 and the carrier 23 adjacent to the toner hopper 45 is used to stir the toner 21 and the carrier 23 so as to give the toner 21 a frictional or peeling charge. A developer stirring mechanism 47 is provided. Inside the toner hopper 45, a toner agitator 48 and a toner replenishing mechanism 49 are disposed as toner supplying means rotated by a driving means (not shown). The toner agitator 48 and the toner replenishing mechanism 49 send out the toner 21 in the toner hopper 45 toward the developer accommodating portion 46 while stirring. A developing sleeve 41 is disposed in a space between the photoconductor 20 and the toner hopper 45. The developing sleeve 41, which is rotationally driven in the direction of the arrow in the figure by a driving means (not shown), is disposed in the interior thereof so as not to change relative position with respect to the developing device 40 in order to form a magnetic brush by the carrier 23. In addition, it has a magnet (not shown) as magnetic field generating means. A doctor blade 43 is integrally attached to the developer accommodating member 42 on the side facing the side attached to the support case 44. In this example, the doctor blade 43 is disposed in a state where a certain gap is maintained between the tip of the doctor blade 43 and the outer peripheral surface of the developing sleeve 41.

(Image forming apparatus and image forming method)
The image forming apparatus of the present invention uses an electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, and the electrostatic latent image using a developer. Development means for forming a visible image by developing, transfer means for transferring the visible image to a recording medium, and fixing means for fixing the transferred image transferred to the recording medium, Other means are provided as necessary.
The developer is the two-component developer of the present invention.

The image forming method used in the present invention includes an electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier, and developing the electrostatic latent image with a developer to make the visible image visible. A development step for forming an image, a transfer step for transferring the visible image to a recording medium, a fixing step for fixing the transferred image transferred to the recording medium, and further including other steps as necessary. It becomes.
The developer is the two-component developer of the present invention.

  In the image forming apparatus, the linear speed of transfer of the toner image to the recording medium in the secondary transfer unit, that is, the so-called printing speed is not particularly limited and can be appropriately selected according to the purpose, but is 300 mm / sec to 1 1,000 mm / sec is preferable. The transfer time at the nip portion of the secondary transfer means is not particularly limited and can be appropriately selected according to the purpose, but is preferably 0.5 msec to 20 msec.

  The image forming apparatus is preferably a tandem type having a plurality of sets of an electrostatic latent image carrier, a charging unit, an exposure unit, a developing unit, a primary transfer unit, and a cleaning unit. In the so-called tandem type in which a plurality of electrostatic latent image carriers are arranged and developed one color at the time of each rotation, an electrostatic latent image forming step, a developing step, and a transferring step are performed for each color. Since each color toner image is formed, the difference between the single-color image formation speed and the full-color image formation speed is small, and there is an advantage that it can cope with high-speed printing. However, since each color toner image is formed on a separate electrostatic latent image carrier and each color toner layer is stacked (color overlap) to form a full color image, the chargeability between the toner particles of each color is improved. If there are variations in characteristics such as differences, a difference occurs in the amount of toner developed by toner particles of each color, the change in the hue of the secondary color due to color superposition increases, and the color reproducibility decreases.

  In the toner used in the tandem type image forming apparatus, the amount of developing toner for controlling the balance of each color is stabilized (there is no variation among the toner particles of each color), and the toner particles of each color are static. It is preferable that the adhesion to the electrostatic latent image carrier and the recording medium is uniform.

  It is preferable that the charging unit applies at least a DC voltage on which an alternating voltage is superimposed. By applying a DC voltage with an alternating voltage superimposed on it, the surface voltage of the electrostatic latent image carrier can be stabilized at a desired value compared to when only a DC voltage is applied. Is possible. Further, it is preferable that the charging unit performs charging by bringing a charging member into contact with the electrostatic latent image carrier and applying a voltage to the charging member. By charging the electrostatic latent image bearing member with a charging member and applying a voltage to the charging member for charging, the effect of uniform charging obtained by applying a DC voltage superimposed with an alternating voltage is further improved. It becomes possible to make it.

  The fixing means is composed of a magnetic metal and heated by electromagnetic induction, is stretched between a fixing roller arranged in parallel with the heating roller, the heating roller and the fixing roller, and is heated by the heating roller. At the same time, an endless belt-shaped toner heating medium (heating belt) rotated by these rollers is pressed against the fixing roller via the heating belt and rotated in the forward direction with respect to the heating belt to form a fixing nip portion. By having the pressure roller, the temperature of the fixing belt rises in a short time, and stable temperature control becomes possible. Further, even when a recording medium having a rough surface is used, the fixing belt acts in a state corresponding to the surface of the transfer paper to some extent at the time of fixing, so that sufficient fixing properties can be obtained.

  The fixing unit is preferably an oilless type or a small amount of oil application type. In order to achieve this, it is preferable to fix the toner particles containing a release agent (wax) and further finely dispersed in the toner particles. In the case where the release agent is easily oozed out during fixing due to the toner in which a small amount of the release agent is dispersed in the toner particles, and the oil application effect is reduced in the oil-less fixing device or in the trace amount oil application fixing device. Also, the transfer of toner to the belt side can be suppressed. In order for the release agent to exist in a dispersed state in the toner particles, it is preferable that the release agent and the binder resin are not compatible. Further, in order to finely disperse the release agent in the toner particles, for example, there is a method using a shearing force of kneading at the time of toner production. The dispersion state of the release agent can be determined by observing a thin film slice of toner particles with a TEM. The dispersion diameter of the release agent is preferably small, but if it is too small, there are cases where the seepage during fixing is insufficient. Therefore, if the release agent can be confirmed at a magnification of 10,000, it is determined that the release agent exists in a dispersed state. If the size is 10,000 times and the release agent cannot be confirmed, even if finely dispersed, there is a case where the bleeding at the time of fixing is insufficient.

Here, an embodiment of the image forming apparatus of the present invention will be described with reference to FIG.
As shown in FIG. 3, the electrostatic latent image carrier 20 is rotationally driven at a predetermined peripheral speed, and the peripheral surface of the electrostatic latent image carrier 20 is uniformly charged to a predetermined positive or negative potential by the charging device 32. Is done. Next, the peripheral surface of the electrostatic latent image carrier 20 is exposed by the exposure device 33, and electrostatic latent images are sequentially formed. Furthermore, the electrostatic latent image formed on the peripheral surface of the electrostatic latent image carrier 20 is developed by the developing device 40 using the two-component developer of the present invention including a carrier and toner to form a toner image. Is done. Next, the toner image formed on the peripheral surface of the electrostatic latent image carrier 20 is synchronized with the rotation of the electrostatic latent image carrier 20, and the electrostatic latent image carrier 20 and the transfer device 50 are fed from the paper feeding unit. The images are sequentially transferred onto the transfer paper fed during the period. Further, the transfer paper onto which the toner image has been transferred is separated from the peripheral surface of the electrostatic latent image carrier 20, introduced into the fixing device and fixed, and then transferred to the outside of the image forming apparatus as a copy (copy). Printed out. On the other hand, after the toner image is transferred, the surface of the electrostatic latent image carrier 20 is cleaned by the cleaning device 60 after the remaining toner is removed, and then the static electricity is removed by the static eliminator 70 to repeatedly form images. used.

  In the image forming apparatus of the present invention, it is preferable that the developer for replenishment is replenished to the developing device and development is performed while discharging the excess developer in the developing device. The replenishment developer is preferably filled in a storage container whose shape is easily deformed, and is provided with a developer replenishment device that sucks the replenishment developer with a suction pump and supplies the replenishment developer to the developing device. .

  FIG. 4 is a schematic view showing another example of the image forming apparatus of the present invention. In FIG. 4, the photosensitive member 20 is provided with at least a photosensitive layer on a conductive support. The photosensitive member 20 is driven by driving rollers 24a and 24b, and is charged by a charging device 32, image exposure by an exposure device 33, development by a developing device 40, transfer using a transfer device 50 having a corona charger, exposure light source before cleaning. 26, the pre-cleaning exposure by the nozzle 26, the cleaning by the brush-like cleaning means 64 and the cleaning blade 61, and the static elimination by the static eliminator 70 are repeated. Note that pre-cleaning exposure is performed on the photoconductor 20 (of course, in this case, the support is translucent) from the support side.

(Process cartridge)
The process cartridge of the present invention comprises at least an electrostatic latent image carrier and developing means for visualizing the electrostatic latent image on the electrostatic latent image carrier using a developer. Other means are provided as necessary.
The developer is the two-component developer of the present invention.

An embodiment of the process cartridge will be described with reference to FIG.
A process cartridge 10 shown in FIG. 5 includes an electrostatic latent image carrier 11, a charging device 12 for charging the electrostatic latent image carrier, and an electrostatic latent image formed on the electrostatic latent image carrier. A developing device 13 for developing a toner image by developing using the two-component developer and a toner image formed on the electrostatic latent image bearing member after transferring the toner image to a recording medium; It has a cleaning device 14 for removing toner remaining on it, and is detachable from a main body of an image forming apparatus such as a copying machine or a printer.

  The process cartridge is preferably one that discharges excess developer and is newly replenished with developer. An electrostatic latent image carrier and an electrostatic latent image on the electrostatic latent image carrier. And a developing device that visualizes the image, and is detachably mounted on the main body of the image forming apparatus that replenishes the developer for replenishment and discharges the developer from the developing device. It is preferable. Moreover, it is preferable that the developing device in the process cartridge has the developer in the developing device.

Examples of the present invention will be described below, but the present invention is not limited to these examples.
In addition, the arithmetic average surface roughness Ra1 of the carrier, the arithmetic average surface roughness Ra2 of the core material, the average layer thickness difference of the coating layer, the weight average particle size of the core material, and the average particle size of the fine particles measured in Examples and Comparative Examples Diameter, average particle diameter of toner, particle size distribution index of coalesced particles (Db ₅₀ / Db ₁₀ ), number of primary particles in 1000 particles of external additive (Nx), fine particle size relative to average thickness h of coating layer The ratio D / h of the volume average particle diameter D is a value obtained by measurement by the measurement method described above.

(External Additive Production Examples 1 to 10)
-Production of external additives 1-10-
The external additives 1 to 9 are produced by mixing primary particles having various volume average particle diameters described in Table 1 below and a treatment agent with a spray dryer and firing them under the conditions described in Table 1. Thus, the primary particles were produced by coalescence. In addition, the external additive 10 was produced by subjecting the primary particles having the volume average particle diameters shown in Table 1 to a hydrophobic treatment, but without the treatment with the treatment agent.
The treating agent was prepared by adding 0.1 part by mass of a processing aid (water or 1% by mass acetic acid aqueous solution) to 1 part by mass of methyltrimethoxysilane. Table 1 shows the volume average particle diameter, shape, and the like of secondary particles produced by coalescing the primary particles.

* The ratio (%) of primary particles is a ratio determined by the following formula, (Nx / 1000) × 100, from the number of primary particles Nx in 1,000 external additive particles.

(Toner Production Example 1)
<Manufacture of toner base particles>
-Synthesis of crystalline polyester resin-
In a 5-liter four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple, 2,300 g of 1,6-hexanediol, 2530 g of fumaric acid, 291 g of trimellitic anhydride, and hydroquinone4. 9 g was added and reacted at 160 ° C. for 5 hours, then heated to 200 ° C. and reacted for 1 hour, and further reacted at 8.3 kPa for 1 hour to obtain crystalline polyester resin 1.
The obtained crystalline polyester resin 1 had an DSC endothermic peak temperature of 120 ° C., a number average molecular weight Mn of 1,500, a weight average molecular weight Mw of 9,000, and an SP value of 10.8.

-Synthesis of non-crystalline polyester (low molecular polyester) resin-
In a 5-liter four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, 229 parts by mass of a bisphenol A ethylene oxide 2 mol adduct, 529 parts by mass of a bisphenol A propylene oxide 3 mol adduct, Add 208 parts by mass of terephthalic acid, 46 parts by mass of adipic acid and 2 parts by mass of dibutyltin oxide, react at 230 ° C. for 7 hours under normal pressure, and further react for 4 hours at a reduced pressure of 10 mmHg to 15 mmHg. 44 parts by mass of trimellitic acid was added and reacted at 180 ° C. for 2 hours under normal pressure to obtain [Amorphous Polyester 1].

-Synthesis of polyester prepolymer-
In a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, 682 parts by mass of bisphenol A ethylene oxide 2 mol adduct, 81 parts by mass of bisphenol A propylene oxide 2 mol adduct, 283 parts by mass of terephthalic acid, 22 parts by mass of merit acid and 2 parts by mass of dibutyltin oxide were added, reacted at 230 ° C. for 8 hours under normal pressure, and further reacted for 5 hours at a reduced pressure of 10 mmHg to 15 mmHg to obtain [Intermediate Polyester 1].
The obtained [Intermediate Polyester 1] had a number average molecular weight of 2,100, a weight average molecular weight of 9,500, a glass transition temperature Tg of 55 ° C., an acid value of 0.5 mgKOH / g, and a hydroxyl value of 51 mgKOH / g. It was.

  Next, 410 parts by mass of [Intermediate Polyester 1], 89 parts by mass of isophorone diisocyanate, and 500 parts by mass of ethyl acetate are placed in a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe. The reaction was performed for a while to obtain [Prepolymer 1]. [Prepolymer 1] had a free isocyanate mass% of 1.53%.

-Synthesis of ketimine-
In a reaction vessel equipped with a stirrer and a thermometer, 170 parts by mass of isophoronediamine and 75 parts by mass of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to obtain [ketimine compound 1]. The amine value of the obtained [ketimine compound 1] was 418.

-Preparation of masterbatch (MB)-
1,200 parts by mass of water, carbon black (Printtex 35, manufactured by Dexa) [DBP oil absorption = 42 mL / 100 mg, pH = 9.5] 540 parts by mass, and 1,200 parts by mass of the above [Amorphous Polyester 1] In addition, the mixture was mixed with a Henschel mixer (manufactured by Nippon Coke Kogyo Co., Ltd.), and the mixture was kneaded at 150 ° C. for 30 minutes using two rolls, cooled by rolling, and pulverized with a pulverizer to obtain [Masterbatch 1]. .

-Preparation of oil phase-
In a container in which a stir bar and a thermometer are set, 378 parts by mass of the above [Non-crystalline polyester 1], 110 parts by mass of carnauba wax, a charge control agent (CCA, salicylic acid metal complex E-84, manufactured by Orient Chemical Industry Co., Ltd.) 22 parts by mass and 947 parts by mass of ethyl acetate were charged, the temperature was raised to 80 ° C. with stirring, the temperature was kept at 80 ° C. for 5 hours, and then cooled to 30 ° C. in 1 hour. Next, 500 parts by mass of [Masterbatch 1] and 500 parts by mass of ethyl acetate were charged in a container and mixed for 1 hour to obtain [Raw material solution 1].

  Transfer 1324 parts by mass of the above [Raw Material Solution 1] to a container and use a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.). Filled with 80% by volume of zirconia beads, carbon black and wax were dispersed under conditions of 3 passes. Subsequently, 1,042.3 parts by mass of a 65% by mass ethyl acetate solution of [Amorphous Polyester 1] was added, and one pass was performed with a bead mill under the above conditions to obtain [Pigment and Wax Dispersion 1]. The obtained [Pigment and Wax Dispersion 1] had a solid content concentration (130 ° C., 30 minutes) of 50% by mass.

-Preparation of crystalline polyester dispersion-
100 g of [Crystalline Polyester Resin 1] and 400 g of ethyl acetate were put into a metal 2 L container, dissolved by heating at 75 ° C., and then rapidly cooled in an ice-water bath at a rate of 27 ° C./min. To this, 500 mL of glass beads (diameter 3 mm) was added, and pulverized for 10 hours with a batch type sand mill (manufactured by Campehapio) to obtain [Crystalline Polyester Dispersion 1].

-Synthesis of organic fine particle emulsion-
In a reaction vessel in which a stir bar and a thermometer are set, 683 parts by mass of water, 11 parts by mass of sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries, Ltd.), 138 parts by mass of styrene Part, 138 parts by weight of methacrylic acid, and 1 part by weight of ammonium persulfate were added and stirred at 400 rpm for 15 minutes to obtain a white emulsion. The system was heated to raise the system temperature to 75 ° C. and reacted for 5 hours. Further, 30 parts by mass of a 1% by mass aqueous ammonium persulfate solution was added, and the mixture was aged at 75 ° C. for 5 hours. [Fine particle dispersion 1] was obtained.
The volume average particle diameter of the obtained [fine particle dispersion 1] measured by a particle size distribution measuring device (LA-920, manufactured by Horiba, Ltd.) was 0.14 μm. A portion of the obtained [fine particle dispersion 1] was dried to isolate the resin component.

-Preparation of aqueous phase-
990 parts by weight of water, 83 parts by weight of the above [fine particle dispersion 1], 37 parts by weight of 48.5% by weight aqueous solution of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7, manufactured by Sanyo Chemical Industries, Ltd.), and 90 parts by weight of ethyl acetate The parts were mixed and stirred to obtain a milky white liquid. This was designated as [Aqueous Phase 1].

-Emulsification and solvent removal-
[Pigment and Wax Dispersion 1] 664 parts by mass, [Prepolymer 1] 109.4 parts by mass, [Crystalline Polyester Dispersion 1] 73.9 parts by mass, and [Ketimine Compound 1] 4.6 Part by mass is put in a container, and mixed with TK homomixer (Primix Co., Ltd.) at 5,000 rpm for 1 minute. Then, 1,200 parts by mass of [Aqueous phase 1] is added to the container, and the number of revolutions is increased with TK homomixer The mixture was mixed at 13,000 rpm for 20 minutes to obtain [Emulsion slurry 1].
[Emulsion slurry 1] was put into a container equipped with a stirrer and a thermometer, and after removing the solvent at 30 ° C for 8 hours, aging was carried out at 45 ° C for 4 hours to obtain [Dispersion slurry 1].

-Cleaning and drying-
After filtering 100 parts by mass of [Dispersion Slurry 1] under reduced pressure, washing and drying were performed as follows.
(1): 100 parts by mass of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
(2): 100 parts by mass of a 10% by mass aqueous sodium hydroxide solution was added to the filter cake of (1), mixed with a TK homomixer (30 minutes at 12,000 rpm), and then filtered under reduced pressure.
(3): 100 parts by mass of 10 mass% hydrochloric acid was added to the filter cake of (2), mixed with a TK homomixer (10 minutes at 12,000 rpm), and then filtered.
(4): Add 300 parts by mass of ion-exchanged water to the filter cake of (3), mix with a TK homomixer (rotation speed 12,000 rpm for 10 minutes), and then filter twice to perform [Filter cake 1]. Obtained.
[Filter cake 1] was dried at 45 ° C. for 48 hours in a circulating drier, and sieved toner base particles were obtained with an opening of 75 μm mesh.

-External treatment-
100 parts by mass of the obtained toner base particles, 2.0 parts by mass of the external additive 1 in Table 1, 2.0 parts by mass of silica having an average particle diameter of 20 nm, and titanium oxide having an average particle diameter of 20 nm of 0. Six parts by mass were mixed with a Henschel mixer, and passed through a sieve having a mesh size of 500 mesh to obtain toner 1.

(Toner Production Examples 2 to 10)
In the toner production example 1, toners 2 to 10 were produced in the same manner as in the toner production example 1 except that the external additive 1 was replaced with the external additives 2 to 10 shown in Table 1.

(Manufacture example 1 of a core material)
MnCO ₃ , Mg (OH) ₂ , Fe ₂ O ₃ , and SrCO ₃ powders were weighed and mixed to obtain a mixed powder.
The mixed powder was calcined at 850 ° C. for 1 hour in an air atmosphere in a heating furnace, and the obtained calcined product was cooled and pulverized to obtain a powder having an average particle size of 3 μm or less.
A dispersant and water were added to the powder to form a slurry, which was supplied to a spray dryer and granulated to obtain a granulated product having an average particle size of 40 μm.
The obtained granulated material was loaded into a firing furnace and fired at 1,180 ° C. for 4 hours in a nitrogen atmosphere. The obtained fired product was pulverized by a pulverizer, and then the particle size was adjusted by sieving to obtain spherical ferrite particles (core material 1) having a volume average particle size of 35 μm.
It was carried out resulting component analysis of the core _{1, MnO: 40.0mol%, MgO} : 10.0mol%, Fe 2 O 3: 50mol%, SrO: was 0.4 mol%. Moreover, arithmetic mean surface roughness Ra2 was 0.63 micrometer.

(Manufacturing example 2 of core material)
Similar to Production Example 1 of the core material, a granulated product having an average particle size of about 40 μm was obtained. The granulated product was loaded into a firing furnace and fired at 1,120 ° C. for 4 hours in a nitrogen atmosphere. The obtained fired product was pulverized with a pulverizer, and the particle size was adjusted by sieving to obtain spherical ferrite particles (core material 2) having a volume average particle size of about 35 μm.
It was carried out resulting component analysis of the core member _{2, MnO: 40.0mol%, MgO} : 10.0mol%, Fe 2 O 3: 50mol%, SrO: was 0.4 mol%. Moreover, arithmetic mean surface roughness Ra2 was 0.85 micrometer.

(Manufacturing example 3 of core material)
A granulated product having an average particle size of about 40 μm was obtained in the same manner as in Production Example 1 of the core material. The granulated product was loaded into a firing furnace and fired at 1,080 ° C. for 4 hours in a nitrogen atmosphere. The obtained fired product was pulverized with a pulverizer, and then the particle size was adjusted by sieving to obtain spherical ferrite particles (core material 3) having a volume average particle size of about 35 μm.
The obtained core material 3 had an arithmetic average surface roughness Ra2 of 1.03 μm.

(Manufacturing example 4 of core material)
MnCO ₃ , Mg (OH) ₂ , Fe ₂ O ₃ , and CaCO ₃ powders were weighed and mixed to obtain a mixed powder.
The mixed powder was calcined in a heating furnace at 850 ° C. for 1 hour in the air atmosphere, and the obtained calcined product was cooled and pulverized to obtain a powder having an average particle size of 3 μm or less.
A dispersant and water were added to the powder to form a slurry, which was supplied to a spray dryer and granulated to obtain a granulated product having an average particle size of about 40 μm.
The granulated product was charged into a firing furnace and fired at 1,200 ° C. for 5 hours in a nitrogen atmosphere.
The obtained fired product was pulverized with a pulverizer, and the particle size was adjusted by sieving to obtain spherical ferrite particles (core material 4) having a volume average particle size of about 35 μm.
It was carried out resulting component analysis of the core _{4, MnO: 44.3mol%, MgO} : 0.7mol%, Fe 2 O 3: 53mol%, CaO: was 2.0 mol%. The arithmetic average surface roughness Ra2 was 0.68 μm.

(Manufacturing example 5 of core material)
MnCO ₃ , Mg (OH) ₂ and Fe ₂ O ₃ were weighed and mixed to obtain a mixed powder.
The mixed powder was calcined in a heating furnace at 900 ° C. for 3 hours in the air atmosphere, and the obtained calcined product was cooled and pulverized to obtain a powder having an average particle diameter of 1 μm.
A dispersant and water were added to the powder to form a slurry, which was supplied to a spray dryer and granulated to obtain a granulated product having an average particle size of about 40 μm.
The granulated product was loaded into a firing furnace and fired at 1,250 ° C. for 5 hours in a nitrogen atmosphere.
The obtained fired product was pulverized by a pulverizer, and then the particle size was adjusted by sieving to obtain spherical ferrite particles (core material 5) having a volume average particle size of about 35 μm.
Was subjected to component analysis of the obtained core material 5, MnO: 46.2mol%, MgO : 0.7mol%, Fe 2 O 3: was 53 mol%. Moreover, arithmetic mean surface roughness Ra2 was 0.45 micrometer.

(Production Example 1 of Conductive Fine Particles)
100 g of aluminum oxide (manufactured by Sumitomo Chemical Co., Ltd., AKP-30) was dispersed in 1 liter of water to form a suspension, and this liquid was heated to 70 ° C. A solution obtained by dissolving 100 g of stannic chloride and 3 g of phosphorus pentoxide in 1 liter of 2N hydrochloric acid and 12% by mass of aqueous ammonia were dropped into the suspension over 2 hours so that the pH of the suspension was 7-8. did. After dropping, the cake obtained by filtering and washing the suspension was dried at 110 ° C. Next, this dried powder was treated in a nitrogen stream at 500 ° C. for 1 hour to obtain conductive fine particles 1.

(Production example 2 of conductive fine particles)
A tin oxide fine powder (primary particle size 50 nm) having a BET surface area of 50 m ² / g is heated in contact with acetone gas in a nitrogen atmosphere, and maintained at a temperature of 300 ° C. for 2 hours to perform surface modification treatment, Conductive particles 3 were obtained.
100 g of aluminum oxide (manufactured by Sumitomo Chemical Co., Ltd., AKP-30) was dispersed in 1 liter of water to form a suspension, and this liquid was heated to 70 ° C. To this suspension, a solution of 10 g of stannic chloride and 0.30 g of phosphorus pentoxide dissolved in 100 mL of 2N hydrochloric acid and 12% by mass aqueous ammonia was added for 12 minutes so that the pH of the suspension would be 7-8. It was dripped. After dropping, the cake obtained by filtering and washing the suspension was dried at 110 ° C. Next, this dry powder was treated in a nitrogen stream at 500 ° C. for 1 hour to obtain conductive fine particles 2.

(Production Example 3 of Conductive Fine Particles)
As conductive fine particles, Black Pearls-2000 (manufactured by Cabot, particle size: 12 nm, specific surface area 1,500 mm ² / g, aspect ratio 3), 100 g of aluminum oxide (manufactured by Sumitomo Chemical Co., Ltd., AKP-30) in 1 liter of water. Dispersed to form a suspension, and this liquid was heated to 70 ° C. A suspension of 150 g of stannic chloride and 4.5 g of phosphorus pentoxide in 1.5 liters of 2N hydrochloric acid and 12% by mass aqueous ammonia was added to the suspension so that the pH of the suspension was 7-8. The solution was added dropwise over 3 hours. After dropping, the cake obtained by filtering and washing the suspension was dried at 110 ° C. Next, this dried powder was treated in a nitrogen stream at 500 ° C. for 1 hour to obtain conductive fine particles 3.

(Synthesis example 1 of carrier coating layer resin)
300 g of toluene was charged into a flask equipped with a stirrer, and the temperature was raised to 90 ° C. under a nitrogen gas stream. Subsequently, 3-methacryloxypropyl represented by the following structural formula: CH ₂ ═CMe—COO—C ₃ H ₆ —Si (OSiMe ₃ ) ₃ (wherein Me is a methyl group) Tris (trimethylsiloxy) silane 84.4 g (200 mmol, Silaplane TM-0701T, manufactured by Chisso Corporation), 3-methacryloxypropylmethyldiethoxysilane 39 g (150 mmol), methyl methacrylate 65.0 g (650 mmol), and 2 , 2'-azobis-2-methylbutyronitrile 0.58 g (3 mmol) was added dropwise over 1 hour. After completion of the dropwise addition, a solution prepared by dissolving 0.06 g (0.3 mmol) of 2,2′-azobis-2-methylbutyronitrile in 15 g of toluene was further added (2,2′-azobis-2-methylbutyro A total amount of nitrile 0.64 g, 3.3 mmol) was mixed at 90 ° C. to 100 ° C. for 3 hours and radical copolymerized to obtain a methacrylic copolymer (coating layer resin 1).
The resulting coating layer resin 1 had a weight average molecular weight of 33,000. Subsequently, it diluted with toluene so that the non volatile matter of this resin 1 might be 25 mass%. The viscosity of the coating layer resin 1 solution thus obtained was 8.8 mm ² / s, and the specific gravity was 0.91.

(Synthesis example 2 of carrier coating layer resin)
Synthesis of the carrier coating layer resin in Synthesis Example 1 of the carrier coating layer resin except that 39 g of 3-methacryloxypropylmethyldiethoxysilane was replaced with 37.2 g (150 mmol) of 3-methacryloxypropyltrimethoxysilane. In the same manner as in Example 1, radical copolymerization was performed to obtain a methacrylic copolymer (coating layer resin 2).
The resulting coating layer resin 2 had a weight average molecular weight of 34,000. Subsequently, it diluted with toluene so that the non volatile matter of this methacrylic copolymer solution might be 25 mass%. The viscosity of the coating layer resin 2 solution thus obtained was 8.7 mm ² / s, and the specific gravity was 0.91.

(Preparation of carrier coating layer resin 3)
118.69 parts by mass of acrylic resin solution (Hitaroid 3001, manufactured by Hitachi Chemical Co., Ltd., solid content 50 mass%), 37.18 parts by mass of guanamine solution (My Coat 106, manufactured by Mitsui Cytec Co., Ltd., solid content 70 mass%) , 0.68 parts by mass of acidic catalyst (Catalyst 4040, manufactured by Mitsui Cytec Co., Ltd., solid content: 40% by mass), 400 parts by mass of toluene and 400 parts by mass of butyl cellosolve are dispersed for 10 minutes with a homomixer, and the coating layer resin 3 A solution was prepared.

Example 1
<Preparation of two-component developer>
-Fabrication of carrier-
A coating layer forming solution (solid content: 10% by mass) having the following composition was prepared by media dispersion for 2 hours. The obtained coating layer forming solution was applied to the core material 1 of Production Example 1 of the core material of 1,000 parts by mass and dried. Here, application | coating thru | or drying were performed using the fluid bed type | mold coating apparatus which controlled the temperature in a fluid tank to each 70 degreeC. The obtained carrier was baked at 180 ° C. for 2 hours in an electric furnace to obtain carrier 1.
The properties of the carrier 1 of Example 1 obtained are shown in Table 2.

[Composition of coating layer forming solution]
・ Coating layer resin (Resin 2 in Synthesis Example 2 of coating layer resin, solid content: 75 mass%): 30 parts by mass ・ Conductive fine particles of Production Example 1 of conductive fine particles: 1—56 parts by mass Titanium diisopropoxybis (ethyl acetoacetate), ORGATICS TC-750, manufactured by Matsumoto Fine Chemical Co., Ltd.] ... 4 parts by mass Silane coupling agent (SH6020, manufactured by Toray Dow Corning Co., Ltd.) 6 parts by mass-Toluene: remaining

-Production of developer-
930 parts by mass of the obtained carrier 1 and 70 parts by mass of the toner 1 produced in the toner production example 1 were mixed and stirred at 81 rpm for 5 minutes using a turbuler mixer to produce a two-component developer. did.

(Examples 2-75 and Comparative Examples 1-16)
Example 1 was the same as Example 1 except that the type of core material, type of fine particles, dispersion method, production method, carrier, toner, and the like were changed as shown in Table 2, Table 3, and Table 4. A two-component developer was prepared.
In Examples 74 and 75, as the replenishment developer, the same two-component developer prepared in Examples 74 and 75 was filled in the toner cartridge, and the premix ratio was 5 mass% and 10 mass%. It added so that it might become.

  Next, various characteristics were evaluated for each of the two-component developers obtained in Examples and Comparative Examples as described below. The results are shown in Table 2, Table 3, and Table 4.

<Evaluation of the effect of previous image history (effect of ghost image)>
Each produced developer and each replenishment developer are set in a commercially available digital full-color printer (RICOH Pro C901, manufactured by Ricoh Co., Ltd.), and a character chart with an image area of 2% (size of one character: about 2 mm × 2 mm) 100,000 sheets were output. After that, the vertical band charts of the normal image and the abnormal image shown in FIG. 6A and FIG. 6B are printed, and the influence of the immediately preceding image history is evaluated by measuring the density difference between the sleeve one round (a) and one round after (b). did. For the measurement, a color measuring device (X-Rite 938, manufactured by X-Rite) was used. Measurement was performed at three locations of the center, rear, and front of the sleeve, and the average density difference was taken as ΔID. The evaluation criteria were as follows.
〔Evaluation criteria〕
◎: ΔID is 0.01 or less ○: ΔID is more than 0.01 and 0.03 or less Δ: ΔID is more than 0.03 and 0.06 or less ×: ΔID is more than 0.06 Here, ◎, ○, △, and × are ◎: very good, ◯: good, △: acceptable, ×: unusable levels for practical use, ◎, ○, and △ are acceptable, It was rejected.

<Transferability>
After transferring the image area ratio 20% chart from the photoconductor to the paper, the transfer residual toner on the photoconductor immediately before the cleaning is transferred to a white paper with a scotch tape (manufactured by Sumitomo 3M Co., Ltd.). , Manufactured by Macbeth Co.) and evaluated according to the following criteria.
〔Evaluation criteria〕
A: The difference from the blank is less than 0.005.
(Circle): The difference with a blank is 0.005-0.010.
(Triangle | delta): The difference with a blank is 0.011-0.02.
X: The difference with a blank exceeds 0.02.

<Durability evaluation>
Each developer was set in a modified machine obtained by modifying a commercially available digital full-color printer (Ricoh Co., Ltd., IPSiO CX8200) (Ricoh Co., Ltd., RICOH Pro C901), and 100,000 sheets of single color running evaluation were performed. . The amount of decrease in charge and the amount of decrease in resistance after this running was evaluated.

<< Evaluation of charge reduction >>
The charge reduction amount was measured by a general blow-off method (TB-200, manufactured by Toshiba Chemical Co., Ltd.) on a sample that was mixed and frictionally charged at a ratio of 7% by mass of toner to 93% by mass of the carrier before running. The carrier obtained by removing the toner in the developer after running by the blow-off device was subtracted from the charged amount (Q1) obtained by subtracting the charged amount (Q2) measured by the same method as described above.
If the charge reduction amount is within 10.0 μc / g, there is no problem in practical use. Further, since the cause of the decrease in the charge amount is the toner spent on the carrier surface, the toner spent can be evaluated based on the charge decrease amount.

<< Evaluation of resistance drop >>
The amount of decrease in resistance is calculated by inserting a carrier before running between electrodes of a resistance measurement parallel electrode (gap 2 mm), applying a DC of 1,000 V, and measuring a resistance value after 30 seconds using a high resist meter (4329A + LJK 5HVLVWDQFH 0HWHU, horizontal Carrier obtained by removing the toner in the developer after running with the blow-off device (see FIG. 7) from the static resistance value (R1) obtained by converting the value measured by Kawa Hewlett-Packard Co., Ltd. into volume resistivity. Was the amount obtained by subtracting the value (R2) measured by the same method as the resistance measuring method. In FIG. 7, 3 is a carrier, 5 is a toner, and 7 is a brokerage.
If the static resistance value (R1) is 8.0 Log (Ω · cm) or more, it is at a level that causes no problem in actual use.
If the absolute value of the resistance reduction amount is within 3.0 Log (Ω · cm), it is at a level causing no problem in actual use.
Further, the cause of the resistance change is scraping of the carrier coating layer, toner spent, removal of fine particles having a large particle size in the coating layer, and the like, and the occurrence of these is evaluated by the static resistance value and the resistance decrease amount. be able to.
[Durability Evaluation Criteria]
○: Static resistance value is 8.5 Log (Ω · cm) or more, resistance reduction amount is within 3.0 Log (Ω · cm), and charge reduction amount is within 10 μc / g. Δ: Static resistance value is 8.0 Log (Ω).・ Cm) or more and less than 8.5 Log (Ω · cm), the resistance reduction amount is within 3.0 Log (Ω · cm), and the charge reduction amount is within 10 μc / g ×: Static resistance value is 8.0 Log (Ω · cm ), The resistance reduction amount exceeds 3.0 Log (Ω · cm), or the charge reduction amount exceeds 10 μc / g.

* “Coating layer thickness of carrier” in Table 2-1 was obtained by calculation from the prescribed amount, and “Measured coating layer thickness of carrier” is a value obtained by actually measuring the thickness of the coating layer.

* In Table 2-2, “Ratio D / h” represents the volume average particle diameter D of the fine particles with respect to the average thickness h of the coating layer.
* In Table 2-2, “particle size of fine particles” is the primary particle size of the particles alone, “dispersed particle size” is the particle size in the coating layer, and some particles are overlapped. The particle size included.

* In Table 2-4, “ratio of primary particles (%)” is determined from the number Nx of primary particles in 1,000 external additive particles by the following formula: (Nx / 1000) × 100 It is a ratio.

* “Thickness of coating layer of carrier” in Table 3-1 was obtained by calculation from the prescribed amount, and “Measured coating layer thickness of carrier” is a value obtained by actually measuring the thickness of the coating layer.

* In Table 3-2, “Ratio D / h” represents the volume average particle diameter D of the fine particles with respect to the average thickness h of the coating layer.
* In Table 3-2, “Particle size” is the primary particle size of the particles alone, “Dispersed particle size” is the particle size in the coating layer, and there are some overlapping particles. The particle size included.

* In Table 3-4, “ratio of primary particles (%)” is obtained from the number of primary particles Nx in 1,000 external additive particles by the following formula: (Nx / 1000) × 100 It is a ratio.

* In Table 4-1, “carrier coating layer thickness” is obtained by calculation from the prescribed amount, and “carrier actual coating layer thickness” is a value obtained by actually measuring the thickness of the coating layer.

* In Table 4-2, “Ratio D / h” represents the volume average particle diameter D of the fine particles with respect to the average thickness h of the coating layer.
* In Table 4-2, “particle size of fine particles” is the primary particle size of the particles alone, and “dispersed particle size” is the particle size in the coating layer. The particle size included.

* In Table 4-4, “ratio of primary particles (%)” is obtained from the number Nx of primary particles in 1,000 particles of the external additive by the following formula: (Nx / 1000) × 100 It is a ratio.

  From the above results, by using the two-component developers of Examples 1 to 75, transfer performance and charging by toner spent over a long period of time are not affected by the toner consumption history of the immediately preceding image over a long period of time. It has been found that durability is improved with little decrease in property and change in carrier resistance.

As an aspect of this invention, it is as follows, for example.
<1> A two-component developer comprising toner base particles containing a colorant, a release agent, and a binder resin, a toner comprising an external additive, and a carrier,
The carrier has a core and a coating layer that covers the core,
The arithmetic average surface roughness Ra1 of the carrier is 0.50 μm to 0.90 μm,
The coating layer contains a resin and fine particles, and the average layer thickness difference of the coating layer is 0.02 μm to 3.0 μm,
The external additive contains at least coalesced particles, and the coalesced particles are non-spherical secondary particles obtained by coalescing primary particles, and the particle size distribution index of the coalesced particles is expressed by the following formula: A two-component developer represented by (1).
However, in the formula (1), Db ₅₀ is the coalesced particles when the particle diameter (nm) of the coalesced particles is on the horizontal axis and the cumulative value (number%) of the coalesced particles is on the vertical axis. Represents the particle diameter of the coalesced particles having a cumulative value of 50% by number when drawn from the small particle side, and Db ₁₀ represents the particle size of the coalesced particles having the cumulative value of 10% by number. Represents the particle size.
<2> The two-component developer according to <1>, wherein the external additive satisfies the following formula (2).
However, in the formula (2), Nx represents the number of primary particles in 1,000 particles of the external additive, and Nx represents 0.5 g of the external additive in a 50 mL bottle and The mixture is stirred with a mixing stirrer under conditions of 67 Hz and 10 minutes with respect to 49.5 g of the carrier, and then observed and measured with a scanning electron microscope.
<3> The two-component development according to any one of <1> to <2>, wherein the ratio D / h of the volume average particle diameter D of the fine particles to the average thickness h of the coating layer is 0.01 to 1.0. It is an agent.
<4> The two-component developer according to any one of <1> to <3>, wherein the content of the fine particles in the coating layer is 40% by mass to 85% by mass.
<5> The ratio Ra1 / Ra2 between the arithmetic average surface roughness Ra1 of the carrier and the arithmetic average surface roughness Ra2 of the core is 0.60 to 1.0, in any one of <1> to <4> The two-component developer described.
<6> Replenishment developer containing toner and carrier is replenished to the developing means in which the two-component developer containing toner and carrier is accommodated, and surplus in the developing means The two-component developer according to any one of <1> to <5>, which is used in an image forming apparatus that performs development while discharging the developed developer.
<7> An electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, and developing the electrostatic latent image using a developer. An image forming apparatus having at least developing means for forming a visual image, transfer means for transferring the visible image to a recording medium, and fixing means for fixing the transferred image transferred to the recording medium,
An image forming apparatus, wherein the developer is the two-component developer according to any one of <1> to <6>.
<8> An electrostatic latent image carrier, and at least developing means for visualizing the electrostatic latent image on the electrostatic latent image carrier using a developer,
A process cartridge, wherein the developer is the two-component developer according to any one of <1> to <6>.

DESCRIPTION OF SYMBOLS 10 Process cartridge 11 Photoconductor 12 Charging apparatus 13 Developing apparatus 14 Cleaning apparatus 20 Electrostatic latent image carrier (photosensitive body)
21 toner 23 carrier 24a, 24b driving roller 26 exposure light source 32 before cleaning 32 charging device 33 exposure device 40 developing device 41 developing sleeve 42 developer accommodating member 43 doctor blade 44 support case 45 toner hopper 46 developer accommodating portion 47 developer agitating mechanism 48 toner agitator 49 toner replenishing mechanism 50 transfer device 60 cleaning device 61 cleaning blade 64 brush-like cleaning means 70 static elimination device

JP 2007-25893 A Japanese Patent No. 3356948 JP 2005-157002 A JP 11-231652 A Japanese Unexamined Patent Publication No. 7-72733 Japanese Patent Laid-Open No. 7-128983 Japanese Patent Laid-Open No. 7-92913 Japanese Patent Laid-Open No. 11-65247 Japanese Patent No. 3030741 JP 2000-112174 A JP 2001-201891 A JP 2001-235894 A Japanese Patent Laid-Open No. 3-100161 Japanese Patent No. 3328013 JP-A-9-319134 Japanese Patent No. 3056122 JP 2010-224502 A

Claims (8)

A two-component developer comprising toner base particles containing a colorant, a release agent, and a binder resin, a toner comprising an external additive, and a carrier,
The carrier has a core and a coating layer that covers the core,
The arithmetic average surface roughness Ra1 of the carrier is 0.50 μm to 0.90 μm,
The coating layer contains a resin and fine particles, and the average layer thickness difference of the coating layer is 0.02 μm to 3.0 μm,
The external additive contains at least coalesced particles, and the coalesced particles are non-spherical secondary particles obtained by coalescing primary particles, and the particle size distribution index of the coalesced particles is expressed by the following formula: A two-component developer represented by (1).
However, in the formula (1), Db ₅₀ is the coalesced particles when the particle diameter (nm) of the coalesced particles is on the horizontal axis and the cumulative value (number%) of the coalesced particles is on the vertical axis. Represents the particle diameter of the coalesced particles having a cumulative value of 50% by number when drawn from the small particle side, and Db ₁₀ represents the particle size of the coalesced particles having the cumulative value of 10% by number. Represents the particle size. The two-component developer according to claim 1, wherein the external additive satisfies the following formula (2).
However, in the formula (2), Nx represents the number of primary particles in 1,000 particles of the external additive, and Nx represents 0.5 g of the external additive in a 50 mL bottle and The mixture is stirred with a mixing stirrer under conditions of 67 Hz and 10 minutes with respect to 49.5 g of the carrier, and then observed and measured with a scanning electron microscope.   The two-component developer according to claim 1, wherein a ratio D / h of the volume average particle diameter D of the fine particles to the average thickness h of the coating layer is 0.01 to 1.0.   The two-component developer according to any one of claims 1 to 3, wherein the content of the fine particles in the coating layer is 40% by mass to 85% by mass.   The two-component developer according to any one of claims 1 to 4, wherein a ratio Ra1 / Ra2 between the arithmetic average surface roughness Ra1 of the carrier and the arithmetic average surface roughness Ra2 of the core is 0.60 to 1.0. .   To the developing means containing a two-component developer containing toner and carrier, a replenishment developer containing toner and carrier is replenished to the developing means, and the development in excess in the developing means The two-component developer according to claim 1, which is used in an image forming apparatus that performs development while discharging the agent. An electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, and developing the electrostatic latent image with a developer to form a visible image An image forming apparatus having at least developing means for forming, transfer means for transferring the visible image to a recording medium, and fixing means for fixing the transferred image transferred to the recording medium,
An image forming apparatus, wherein the developer is the two-component developer according to claim 1. An electrostatic latent image carrier, and at least developing means for visualizing the electrostatic latent image on the electrostatic latent image carrier using a developer,
A process cartridge, wherein the developer is the two-component developer according to any one of claims 1 to 6.