JP2014056005A - Carrier for electrostatic latent image development, two-component developer for electrostatic latent image development, process cartridge, and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide carrier for electrostatic latent image development configured to supply a stable amount of toner to a carrying body for electrostatic latent image development without any influence of hysteresis even after continuous long-term use, and to prevent reduction in carrier resistance due to wear of coating liquid, and to provide a process cartridge using the carrier for electrostatic latent image development and an image forming device.SOLUTION: Carrier for electrostatic latent image development is formed of a carrier particle which includes a core particle having magnetism and a coating layer for coating the core particle. The carrier includes a first coat layer formed of a resin component for the core particle, and a second coat layer formed by containing filler in the resin. In the first coat layer, protrusions are coated at least for the core particle, and uncoated regions are formed between the adjacent protrusions.

Description

  The present invention relates to a carrier for developing an electrostatic latent image, a two-component developer using the carrier, a process cartridge, and an image forming apparatus.

  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 the full-color electrophotographic method, in order to obtain a clear full-color image, 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, image color tone, and the like fluctuate on the recording medium. The cause of the fluctuation of the toner amount on the electrostatic latent image bearing member may be the fluctuation of the toner charge amount, but in particular, the layer thickness is provided to be regulated on the developer toner conveying sleeve. Both the one-component development method that transports the toner layer to the development nip area for development, and the two-component development method that repeats the formation and movement of a magnetic brush consisting of a carrier for holding toner to provide an electrostatic latent image. In the hybrid development system in which the systems are mixed, it is reported that the difference in the toner amount on the toner carrier is due to a so-called hysteresis phenomenon (ghost phenomenon) that appears as a density difference on the image at the next development ( For example, 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 carrying member with a scraper or a toner collecting roll after developing and before resupplying the toner (see, for example, Patent Documents 2 to 4). Further, a method has been proposed in which the residual toner on the toner carrier is collected on a magnetic roll by a potential difference and the hysteresis phenomenon is eliminated by stabilizing the amount of toner on the toner carrier (see, for example, Patent Document 5). Further, a full width at half maximum, which is a half value of the peak value of the magnetic flux density of the magnetic roll, is set between the developer carrier and the toner carrier to stabilize the collection and supply of toner on the developer carrier. Thus, a method of eliminating the history phenomenon has been proposed (see, for example, 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. A method has been proposed to eliminate the hysteresis phenomenon by increasing the amount of toner supplied to the body at a time, supplying the toner until the amount of toner on the toner carrier is saturated, and keeping the amount of toner on the toner carrier constant. (For example, refer to 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, for example, Patent Document 8).

  The hysteresis phenomenon in the two-component development method is caused by the fact that the two-component developer is not normally peeled off. The developer is peeled off by using an odd number of magnets in the developing sleeve and providing a pair of magnets with the same polarity below the rotation axis of the developing sleeve to create a peeling region where the magnetic force is almost zero. Is used to let the developer after development drop naturally. However, 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. 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, the image density is normal for one round of the sleeve, whereas the image density becomes thin after the second round.

  As a method of eliminating the hysteresis phenomenon in the two-component development method, for example, a method is proposed in which a scooping roll having a magnet inside is arranged in the vicinity of the peeling area on the developing sleeve, and the developer is peeled off with the magnetic force. (For example, 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, even with the above proposal, there is a problem that a stable toner amount cannot be supplied to the electrostatic latent image developing carrier because it is affected by a hysteresis phenomenon if it is continuously used for a long time. In addition, depending on the above proposal, there is a problem that an increase in carrier resistance due to toner spent deposition, which is a problem specific to the two-component development method, cannot be reduced. For this reason, it is strongly desired to solve such problems at the same time.

  This invention is made | formed in view of this present condition, and makes it a subject to solve the said various problems in the past and to achieve the following objectives. The present invention is capable of supplying a stable toner amount to an electrostatic latent image developing carrier without being affected by a hysteresis phenomenon even when continuously used for a long period of time, and a carrier due to toner spent deposition. It is an object of the present invention to provide an electrostatic latent image developing carrier capable of reducing an increase in resistance, a process cartridge and an image forming apparatus using the electrostatic latent image developing carrier.

The hysteresis phenomenon which is the subject of the present invention is different from the occurrence mechanism in the hysteresis phenomenon in the above-described prior art.
The generation mechanism of the ghost phenomenon in the present invention is considered as follows although the details are not clear. 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.
More specifically, in the non-image area, contrary to the image area, a potential for moving the toner from the electrostatic latent image carrier toward the developing sleeve is formed, so that the toner adheres directly onto the developer carrier. (Toner adhesion occurs on the developer carrying member). When the image portion is developed at the next development in a state where the toner is adhered on the developer carrier in this way, the toner directly adhered onto the developer carrier is charged, and therefore the toner on the developer carrier is charged. The development potential is increased by the potential and the toner development amount is increased.
In addition, since the toner directly adhered onto the developer carrying member is consumed during development, the amount of adhered toner is not constant and 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, development of the subsequent image portion causes the above-described development potential to increase, and the subsequent 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 carrier is consumed when the immediately preceding image is developed, and the above-described effect of increasing the development potential is reduced. Thereafter, the image density does not increase.
As described above, the hysteresis phenomenon that is the subject of the present invention is a phenomenon in which the toner adhesion amount on the developer carrier fluctuates due to the influence of the immediately preceding image, and the density fluctuation of the next image appears due to the fluctuation. .

(1 knowledge about problem solving means)
When developing the image area during the next development with the toner attached on the developer carrier, the toner directly attached on the developer carrier is charged, so only the potential due to the toner on the developer carrier is charged. The development potential is raised and the toner development amount increases.
On the other hand, it was found from the examination results that the toner development amount has a very strong correlation with the carrier resistance. That is, the development potential raised by the low carrier resistance is alleviated, and the density fluctuation of the next image is less likely to appear. Therefore, it is desired to reduce the resistance per carrier particle by increasing the prescription amount of the conductive fine particles, but it is obvious that so-called carrier adhesion, in which the carrier is developed in the image area, increases.
As a result of diligent studies to solve the above-mentioned object, the present inventors have used the electrostatic latent image developing carrier satisfying the configuration of the present invention, so that even if it is used continuously for a long period of time, it is affected by the hysteresis phenomenon. As a result, the inventors have found that a stable toner amount can be supplied to the electrostatic latent image developing carrier without being received, and that the decrease in carrier resistance due to coating film wear can be reduced, and the present invention has been completed. It was.
The resistance of the carrier is particularly affected mainly at the developing portion, that is, the nip portion between the sleeve and the photosensitive member. It has been found that the relationship between the carrier density and the resistance is large in the nip portion. It is known that there is a limit to the amount of developer developer per unit area on the sleeve in the machine, and if it exceeds that amount, the amount of developer developer will not be stable and will cause more images such as toner dust. Therefore, the amount of developer pump per unit area on the sleeve is limited by the machine. Therefore, by reducing the carrier density, the resistance at the nip portion can be temporarily reduced without lowering the resistance per particle, and the problem has been solved.
The core in the carrier of the present invention occupies 90% or more of the volume. Therefore, it is effective to reduce the bulk density of the core material in order to reduce the bulk density of the carrier.
A resin carrier made of a mixture of a resin and a metal is a typical method for reducing the bulk density of the core material, but carrier adhesion due to a decrease in magnetization is inevitable. As a result of intensive studies, particles 1 were prepared by using MnCO ₃ , Mg (OH) ₂ , and Fe ₂ O ₃ powder as the core material and adjusting the degree of sintering when granulating from the slurry in the production process. It has been found that the bulk density of the grains can be lowered. Moreover, since sintering was not performed completely, it was found that the surface of the core material was made uneven so that the bulk density of the core material could be lowered.
By providing unevenness on the surface of the core material, it is possible to provide unevenness to the carrier after coating. As a result, the bulk density of the entire carrier can be lowered, and the carrier particles can mesh with each other at the nip portion, so that the density can be increased without imposing an excessive load on the carrier.
On the other hand, by providing unevenness on the surface of the core material, the damage to the carrier protrusion when it is turned into a carrier increases, the coating layer is easily scraped, and the resistance decreases with time, so the carrier adhesion deteriorates. . With respect to this, a method has been proposed in which the coating layer has a resistance that decreases as it goes outward from the core material, and a method in which one layer of a high resistance layer is coated on the surface of the core material (see, for example, Patent Documents 9 to 10). . However, this method results in a thick coat layer. Since the coating is selectively buried from the core recess, the degree of unevenness of the carrier decreases as the film becomes thicker.
As a result of intensive studies, the present inventor provided a layer made of a resin component or having a high resistance as an undercoat layer on at least the convex portion of the core material, and a carrier coat layer provided thereon. As a result, it was possible to obtain a carrier having irregularities on the carrier surface, a low bulk density, and a low resistance drop due to stress.

This invention is based on the said knowledge by the present inventors, and as means for solving the said subject, it is as follows. That is, the present invention includes the following “electrostatic latent image developing carrier”, “process cartridge”, and “image forming apparatus”.
(1) “An electrostatic latent image developing carrier comprising carrier particles including magnetic core particles and a coating layer covering the core particles, wherein the core particles are composed of resin components. There is one coat layer and a second coat layer containing a filler in the resin. The first coat layer is coated on at least the projections with respect to the core particles, and is coated between adjacent projections. An electrostatic latent image developing carrier characterized by having no area. "
(2) “The shape factor SF-2 of the core particles is 120 to 160,
The carrier for developing an electrostatic latent image according to item (1), wherein the core particles have an arithmetic average surface roughness Ra of 0.5 μm to 1.0 μm. "
(3) The carrier for developing an electrostatic latent image according to item (1) or (2), wherein the existence probability of carrier particles satisfying the following conditions is 50% by number or more;
-In cross-sectional SEM observation, no filler is present within a radius of 0.1 μm with respect to the convex portion;
-During cross-sectional SEM observation, a filler exists in a radius of 0.3 μm with respect to a single core core recess. "
(4) The electrostatic latent image developing carrier according to any one of (1) to (3), wherein the filler has a particle size of 100 nm to 500 nm.
(5) “The filler is contained in a range of 50 to 500 parts by mass with respect to 100 parts by mass of the resin,” according to any one of the above items (1) to (4). Carrier for electrostatic latent image development. "
(6) “The resin hydrolyzes a copolymer containing at least the A part represented by the following general formula (A) and the B part represented by the following general formula (B) to form a silanol group. The electrostatic latent image developing carrier according to any one of items (1) to (5), which contains a cross-linked product obtained by condensation.

（ただし、一般式（Ａ）中、Ｒ１は、水素原子又はメチル基を表し、Ｒ２は、炭素数１〜４のアルキル基を表し、ｍは、１〜８の整数を表し、Ｘは、１０ｍｏｌ％〜９０ｍｏｌ％を表す。）

(However, in general formula (A), R1 represents a hydrogen atom or a methyl group, R2 represents a C1-C4 alkyl group, m represents the integer of 1-8, X is 10 mol. % To 90 mol%)

（ただし、一般式（Ｂ）中、Ｒ１は、水素原子又はメチル基を表し、Ｒ２は、炭素数１〜４のアルキル基を表し、Ｒ３は、炭素数１〜８のアルキル基又は炭素数１〜４のアルコキシ基を表し、ｍは、１〜８の整数を表し、Ｙは、１０ｍｏｌ％〜９０ｍｏｌ％を表す。）」

(However, in general formula (B), R1 represents a hydrogen atom or a methyl group, R2 represents a C1-C4 alkyl group, and R3 represents a C1-C8 alkyl group or C1. -4 represents an alkoxy group, m represents an integer of 1 to 8, and Y represents 10 mol% to 90 mol%.

(7) “A two-component developer for developing an electrostatic latent image, comprising the carrier for developing an electrostatic latent image according to any one of items (1) to (6) and a toner.”
(8) “The electrostatic latent image carrier and the means for developing the electrostatic latent image formed on the electrostatic latent image carrier using the developer described in (7) above are integrated. The process cartridge is characterized by being supported by. "
(9) “The means for forming an electrostatic latent image on the electrostatic latent image carrier, and the electrostatic latent image formed on the electrostatic latent image carrier, the developer according to item (7)” Means for developing the toner image using toner, means for transferring the toner image formed on the electrostatic latent image carrier to a recording medium, means for fixing the toner image transferred to the previous recording medium, and An image forming apparatus comprising:
(10) The image forming apparatus according to (9), wherein the means for forming the toner image is a means for developing using a developer having a magnetic brush to form a toner image.

  According to the present invention, various problems in the prior art can be solved, and a stable toner amount can be supplied to the electrostatic latent image developing carrier without being affected by the hysteresis even when used continuously for a long period of time. An electrostatic latent image developing carrier capable of reducing an increase in carrier resistance due to toner spent accumulation, and a process cartridge and an image forming apparatus using the electrostatic latent image developing carrier can be provided. .

FIG. 1 is a diagram illustrating an example of a process cartridge according to the present invention. FIG. 2 is a diagram illustrating an example of the image forming apparatus of the present invention. FIG. 3 is a diagram illustrating an example of a method of measuring the electrical resistivity of the electrostatic latent image developing carrier of the present invention. FIG. 4 is a perspective view showing an example of a resistance measurement cell used for measuring the electrical resistivity of the carrier for developing an electrostatic latent image of the present invention. FIG. 5 is a diagram illustrating an example of a normal image and an abnormal image in the vertical band chart. FIG. 6 is a schematic view showing a cross section of the carrier of the present invention. FIG. 7 is a schematic diagram showing the convex portions of the core particle of the present invention.

(Carrier for developing electrostatic latent images)
The carrier for developing an electrostatic latent image of the present invention includes core particles and a coating layer that covers the core particles, and further includes other components as necessary.

<Core particles>
The core particles are not particularly limited as long as they are magnetic core particles, and can be appropriately selected according to the purpose. For example, ferromagnetic metals such as iron and cobalt; oxidation of magnetite, hematite, ferrite, and the like Iron; resin particles in which magnetic materials such as various alloys and compounds are dispersed in a resin. Among these, Mn-based ferrite, Mn-Mg-based ferrite, Mn-Mg-Sr-based ferrite and the like are preferable from the viewpoint of environmental considerations.

-Core particle shape factor SF-1-
The core particles are defined by the shape factor SF-1.
SF-1 defines the degree of roundness of the particles.
As the value of SF-1 increases, the shape of the particles moves away from the circle (spherical shape).

  There is no restriction | limiting in particular as the shape factor SF-1 of the said core particle, According to the objective, it can select suitably.

  The measurement of the core particle shape factor SF-1 is performed by measuring the particle image of the core particle magnified 300 times using a scanning electron microscope (for example, FE-SEM (S-800), manufactured by Hitachi, Ltd.). Individual sampling was performed, and the obtained image information was analyzed by an image analyzer (for example, Luzex AP, manufactured by Nireco) and calculated using the following calculation formula (1).

（ただし、前記計算式（１）中、Ｌは、粒子の絶対最大長（外接円の長さ）を表し、Ａは、粒子の投影面積を表す。）

(However, in the calculation formula (1), L represents the absolute maximum length of the particle (the length of the circumscribed circle), and A represents the projected area of the particle.)

-Shape factor SF-2- of core particle
The core particles are defined by the shape factor SF-2.
SF-2 defines the degree of unevenness of particles.
When the value of SF-2 increases, the unevenness of the surface of the particles becomes severe.

  The shape factor SF-2 of the core particle is not particularly limited as long as it is 120 to 160, and can be appropriately selected according to the purpose. When the shape factor SF-2 is less than 120, the convex portions of the core particles are likely to be covered, and it may not be possible to obtain a low density merit when the carrier is formed. Further, when the shape factor SF-2 exceeds 160, not only the voids in the core particles are increased and the strength of the core particles is weakened, but also when the core is used in a developing device for a long period of time. The exposure of particles is large, and the change in the initial resistance value and the resistance value after use increases, leading to deterioration of carrier adhesion, the amount of toner on the electrostatic latent image carrier, and the way the toner image is formed fluctuates. The image density may fluctuate.

  The core particle shape factor SF-2 was measured by measuring 100 particle images of core particles magnified 300 times using a scanning electron microscope (for example, FE-SEM (S-800), manufactured by Hitachi, Ltd.). Random sampling was performed, and the obtained image information was analyzed by an image analyzer (for example, Luzex AP, manufactured by Nireco) and calculated by using the following calculation formula (2).

（ただし、前記計算式（２）中、Ｐは、粒子の周囲長を表し、Ａは、粒子の投影面積を表す。）

(In the calculation formula (2), P represents the perimeter of the particle, and A represents the projected area of the particle.)

-Arithmetic average surface roughness Ra of core particles-
The arithmetic average surface roughness Ra of the core particles defines the surface roughness of the core particles.
The meaning of defining the arithmetic average surface roughness Ra of the core particle is an atypical core particle greatly deviating from the spherical shape, and the core particle having the shape factor SF-2 in the range of 120 to 160 is used. This is because, when used, the carrier adheres more and is not a subject of the present invention.
The arithmetic average surface roughness Ra of the core particles is not particularly limited as long as it is 0.5 μm to 1.0 μm, and can be appropriately selected according to the purpose, but is preferably 0.6 μm to 0.9 μm. .

  The measurement of the arithmetic average surface roughness Ra of the core particles is performed using an optical microscope (for example, OPTELICS C130, manufactured by LASERTEC) after setting an objective lens magnification of 50 times and capturing an image with a resolution of 0.20 μm. The observation area was 10 μm × 10 μm centering on the apex of the core particles, and the average value of the surface roughness Ra of 100 core particles was measured.

-Grain diameter of core particles-
There is no restriction | limiting in particular as the grain diameter of the said core particle, Although it can select suitably according to the objective, 2 micrometers-8 micrometers are preferable.

-BET specific surface area of core particles-
The BET specific surface area of the core particles is not particularly limited and may be appropriately selected depending on the ^purpose, 0.09m ^{3 /g~0.40m} 3 / g are preferred.

-Weight average particle diameter Dw of core particles-
The weight average particle diameter Dw of the core particles refers to the particle diameter at an integrated value of 50% in the particle size distribution of the core particles obtained by a laser diffraction or scattering method. There is no restriction | limiting in particular as the weight average particle diameter Dw of the said core particle, Although it can select suitably according to the objective, 10 micrometers-80 micrometers are preferable.

  The weight average particle diameter Dw of the core particles is measured by using a microtrac particle size distribution meter (HRA9320-X100, manufactured by Honeywell) as a particle diameter distribution (relationship between number frequency and particle diameter) of particles measured on a number basis. It was measured under the conditions described below using the following formula (3). Each channel represents a length for dividing the particle size range in the particle size distribution chart into measurement width units, and the lower limit value of the particle size stored in each channel is adopted as the representative particle size.

（ただし、前記計算式（３）中、Ｄは、各チャネルに存在する粒子の代表粒径（μｍ）を表し、ｎは、各チャネルに存在する粒子の総数を表す。）

(However, in the calculation formula (3), 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.)

[Measurement condition]
[1] Particle size range: 100 μm to 8 μm
[2] Channel length (channel width): 2 μm
[3] Number of channels: 46
[4] Refractive index: 2.42

<Coating layer>
The coating layer is formed of a coating layer forming solution containing a resin and a filler.
The coating layer is not particularly limited as long as it is a coating layer containing the filler 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 filler with respect to 100 parts by mass of the resin is preferable. When the content of the filler is less than 50 parts by mass, the coating layer may be scraped. When the content exceeds 500 parts by mass, the proportion 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.

  If the thickness of the coating layer is too thin, the surface of the core particles can be easily exposed by stirring in the developing machine, and the change in resistance value may increase. Deterioration of carrier adhesion due to lowering is inevitable. The thickness of the coating layer can be controlled by the content of the resin with respect to the core particles, and is determined by the total of the first coat layer and the second coat layer. There is no restriction | limiting in particular as content with respect to the said core particle of the said resin, Although it can select suitably according to the objective, A core can be formed by the thickness of a coating layer at a local low resistance state. 1.0 mass%-5.0 mass% are preferable with respect to a material.

-Resin-
There is no restriction | limiting in particular in both the 1st coat layer and the 2nd coat layer as said resin, According to the objective, it can select suitably, For example, an acrylic resin, an amino resin, a polyvinyl resin, a polystyrene resin, a halogenated olefin Resin, polyester, polycarbonate, polyethylene, polyvinyl fluoride, polyvinylidene fluoride, polytrifluoroethylene, polyhexafluoropropylene, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene, vinylidene fluoride and non-fluorinated Examples thereof include fluoroterpolymers such as terpolymers with monomers, silicone resins, and the like. These may be used individually by 1 type and may use 2 or more types together. Among these, a silicone resin is preferable.

  There is no restriction | limiting in particular as said resin, Although it can select suitably according to the objective, Resin containing the hardened | cured material of the mixture containing a silane coupling agent and a silicone resin is preferable.

--Silicone resin--
There is no restriction | limiting in particular as said silicone resin, According to the objective, it can select suitably.

  Further, it is obtained by hydrolyzing a copolymer containing at least the A part represented by the following general formula (A) and the B part represented by the following general formula (B) to form a silanol group and condense. A resin containing a cross-linked product can also be used.

（ただし、一般式（Ａ）中、Ｒ^１は、水素原子又はメチル基を表し、Ｒ^２は、炭素数１〜４の同じであっても異なっていてもよいアルキル基を表し、ｍは、１〜８の整数を表し、Ｘは、１０ｍｏｌ％〜９０ｍｏｌ％を表す。）

(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 which may be the same or different, and m is The integer of 1-8 is represented, X represents 10 mol%-90 mol%.)

（ただし、一般式（Ｂ）中、Ｒ^１は、水素原子又はメチル基を表し、Ｒ^２は、炭素数１〜４のアルキル基を表し、Ｒ^３は、炭素数１〜８のアルキル基又は炭素数１〜４のアルコキシ基を表し、ｍは、１〜８の整数を表し、Ｙは、１０ｍｏｌ％〜９０ｍｏｌ％を表す。）

(In 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, and R ³ represents an alkyl group having 1 to 8 carbon atoms or C represents an alkoxy group having 1 to 4 carbon atoms, m represents an integer of 1 to 8, and Y represents 10 mol% to 90 mol%.)

--Silane coupling agent--
The silane coupling agent can stably disperse the filler.
The silane coupling agent is not particularly limited in both the first coat layer and the second coat layer, and can be appropriately selected according to the purpose. For example, r- (2-aminoethyl) aminopropyltrimethoxysilane, r- (2-aminoethyl) aminopropylmethyldimethoxysilane, r-methacryloxypropyltrimethoxysilane, N-β- (N-vinylbenzylaminoethyl) -r-aminopropyltrimethoxysilane hydrochloride, r-glycid Xylpropyltrimethoxysilane, r-mercaptopropyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, vinyltriacetoxysilane, r-chloropropyltrimethoxysilane, hexamethyldisilazane, r-anilinopropyltrimethoxysilane , Vinyl trimethoxy Octadecyldimethyl [3- (trimethoxysilyl) propyl] ammonium chloride, r-chloropropylmethyldimethoxysilane, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, allyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, Examples include 3-aminopropyltrimethoxysilane, dimethyldiethoxysilane, 1,3-divinyltetramethyldisilazane, and methacryloxyethyldimethyl (3-trimethoxysilylpropyl) ammonium chloride. These may be used individually by 1 type and may use 2 or more types together.

  Examples of commercially available silane coupling agents 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, AY4 -158E, Z-6920, Z-6940 (all manufactured by Dow Corning Toray Co., Ltd.).

  There is no restriction | limiting in particular as an addition amount of the said silane coupling agent, Although it can select suitably according to the objective, 0.1 mass%-15 mass% are preferable with respect to the said resin. When the addition amount is less than 0.1% by mass, the adhesion of the core particles, the filler, and the resin is lowered, and the coating layer may fall off during long-term use, and 15% by mass. If it exceeds 1, toner filming may occur during long-term use.

-Filler-
There is no restriction | limiting in particular as said filler, According to the objective, it can select suitably, For example, a conductive filler, a nonelectroconductive filler, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, it is preferable to contain a conductive filler and a non-conductive filler in the coating layer. Moreover, you may use for a 1st coat layer suitably.

The conductive filler refers to a filler having a powder specific resistance value of 100 Ω · cm or less.
The said nonelectroconductive filler points out the filler whose powder specific resistance value exceeds 100 ohm * cm.
The powder specific resistance value of the filler is measured by a powder resistance measurement system (MCP-PD51, manufactured by Dia Instruments) and a resistivity meter (4-terminal 4-probe system, Loresta GP, manufactured by Mitsubishi Chemical Analytech). Was measured under the conditions of a sample of 1.0 g, an electrode interval of 3 mm, a sample radius of 10.0 mm, and a load of 20 kN.

--Conductive filler--
The conductive filler is not particularly limited and may be appropriately selected depending on the intended purpose. For example, tin oxide or oxide may be applied to a substrate such as aluminum oxide, titanium oxide, zinc oxide, barium sulfate, silicon oxide, or zirconium oxide. Examples thereof include a conductive filler formed using indium as a layer; a conductive filler formed using carbon black, and the like. Among these, a conductive filler containing aluminum oxide, titanium oxide, and barium sulfate is preferable.

--Non-conductive filler--
There is no restriction | limiting in particular as said nonelectroconductive filler, According to the objective, it can select suitably, For example, it forms using aluminum oxide, titanium oxide, barium sulfate, zinc oxide, silicon dioxide, zirconium oxide etc. Non-conductive filler etc. are mentioned. Among these, non-conductive fillers containing aluminum oxide, titanium oxide, and barium sulfate are preferable.

--Average particle size of filler--
The average particle size of the filler is not particularly limited and may be appropriately selected depending on the intended purpose. However, the filler tends to come out from the surface of the resin contained in the coating layer, thereby creating a partial low resistance. It is easy to scrape the spent matter on the carrier surface and is excellent in wear resistance, and is preferably 50 nm to 800 nm, and more preferably 200 nm to 700 nm. The average particle size of the filler is measured by randomly measuring 100 particle images of the filler magnified 10,000 times using a scanning electron microscope (for example, FE-SEM (S-800), manufactured by Hitachi, Ltd.). The particle size was sampled and the number average particle size was used.

<Other ingredients>
There is no restriction | limiting in particular as said other component, Although it can select suitably according to the objective, It is preferable to contain a catalyst in the said coating layer, and you may contain a solvent, a hardening | curing agent, etc.

-Catalyst-
The catalyst is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include titanium-based catalysts, tin-based catalysts, zirconium-based catalysts, aluminum-based catalysts, and the like. Examples include acetylacetonato complex, alkylacetoacetate complex, salicylaldehyde complex and the like. These may be used individually by 1 type and may use 2 or more types together. Among these, a titanium-based catalyst is preferable and titanium diisopropoxybis (ethyl acetoacetate) is more preferable in that the effect of promoting the condensation reaction of the silanol group is large and the catalyst is difficult to deactivate.

<Method for producing carrier for developing electrostatic latent image>
The method for producing the carrier for developing an electrostatic latent image is not particularly limited and may be appropriately selected depending on the intended purpose. The first coat layer is a spray coat type Spira coater (Okada Seiko Co., Ltd.) described later. May be used, and the slope type coating apparatus described later may be used. However, the condition change apparatus of the spray coat type Spira coater (Okada Seiko Co., Ltd.) A method of applying the coating layer forming solution containing the resin to the convex portions of the particles is preferable. When applying the first coat layer, condensation of the resin contained in the coating layer may proceed, or after applying the first coat layer, condensation of the resin contained in the coating layer. However, it is preferable to condense the resin after applying the first coat layer.
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. .
There is no restriction | limiting in particular also about a 2nd coat layer, Although it can select suitably according to the objective, For example, it is preferable to use a spray coat type Spira coater (made by Okada Seiko Co., Ltd.).

(Condition changing device for device A Spira coater (Okada Seiko Co., Ltd.)
This method is an example, and can be appropriately changed according to the purpose. First, the spray height is changed to 0.2 mm from the rotating bed, and the spray air flow rate is suppressed to the extent that it does not scatter by bouncing back to the rotating bed. As a result, a thin coat film layer can be obtained on the rotating bed. The core material rolls from the inside to the outside according to the centrifugal force of the disk portion, so that the first coat layer can be obtained only on the convex portion.

(Apparatus B Slope type coating equipment)
The slope type coating apparatus can be described as follows. That is, one metal plate is prepared and provided with an inclination. On the other hand, a coating liquid coating apparatus is provided above. This time, 10 nozzles, similar to the spray coat type Spira coater, were arranged in a horizontal row.
First, a coating solution is applied on the slope from the nozzle. The coating amount is adjusted appropriately. However, if the amount is too small, the solvent will evaporate immediately, so that it will adhere to the metal plate, and if it is too large, the inside of the core irregularities will be coated.
After that, the core material is put on the slope where the coat layer is further drawn. Thereby, a 1st coat layer can be obtained only in a convex part.
By repeating the above several times, the first coat layer can be obtained evenly only by the convex portions. Note that it is desirable to shift the time axis between the coating process and the core material charging process. Hereinafter, this apparatus is referred to as TOYO (TO Yachted Objectst).

-Shape factor of carrier for electrostatic latent image development SF-2-
The electrostatic latent image developing carrier is defined by a shape factor SF-2.
SF-2 defines the degree of unevenness of particles.
When the value of SF-2 increases, the unevenness of the surface of the particles becomes severe.

  The shape factor SF-2 of the carrier for developing an electrostatic latent image is not particularly limited as long as it is 105 to 150, and can be appropriately selected according to the purpose. 120-145 are preferable at the point which can be performed.

  The measurement of the shape factor SF-2 of the carrier for developing an electrostatic latent image is performed by measuring the electrostatic latent image magnified 300 times using a scanning electron microscope (for example, FE-SEM (S-800), manufactured by Hitachi, Ltd.). 100 particle images of the developing carrier are sampled randomly, and the obtained image information is analyzed by an image analyzer (for example, Luzex AP, manufactured by Nireco). As described above, the following calculation formula (2 ).

（ただし、前記式（２）中、Ｐは、粒子の周囲長を表し、Ａは、粒子の投影面積を表す。）

(In the above formula (2), P represents the perimeter of the particle, and A represents the projected area of the particle.)

-Bulk density of electrostatic latent image developing carrier-
The bulk density of the electrostatic latent image developing carrier is not particularly limited as long as the bulk density is 1.8 g / cm ^{3 to} 2.4 g / cm ³ , and can be appropriately selected according to the purpose. . If the bulk density is less than 1.8 g / cm ³ , so-called carrier adhesion is likely to occur where the carrier adheres to the electrostatic latent image carrier, and if it exceeds 2.4 g / cm ³ , the problem cannot be solved. In addition, the agitation stress in the developing machine increases, and the resistance change of the electrostatic latent image developing carrier may increase.

The bulk density of the electrostatic latent image developing carrier was measured by dropping from a 25 mm height container into a 25 cm ³ container from a funnel having an orifice diameter of ³ mm.

-BET specific surface area of electrostatic latent image developing carrier-
The BET specific surface area of the electrostatic latent image carrier is not particularly limited and may be appropriately selected depending on the intended ^purpose, 2.5m ^{3 /g~6.0m} 3 / g are preferred.

-Weight average particle diameter Dw of carrier for developing electrostatic latent image-
The weight average particle diameter Dw of the carrier for developing an electrostatic latent image is a particle diameter at an integrated value of 50% in the particle size distribution of the core particles 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 for electrostatic latent image development, Although it can select suitably according to the objective, 10 micrometers-80 micrometers are preferable.

  As described above, the measurement of the weight average particle diameter Dw of the carrier for developing an electrostatic latent image is 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. It measured on the conditions as described below using the distribution meter (HRA9320-X100, the product made by Honewell), and computed using the following formula (3). Each channel represents a length for dividing the particle size range in the particle size distribution chart into measurement width units, and the lower limit value of the particle size stored in each channel is adopted as the representative particle size.

（ただし、前記式（３）中、Ｄは、各チャネルに存在する粒子の代表粒径（μｍ）を表し、ｎは、各チャネルに存在する粒子の総数を表す。）

(However, in said Formula (3), D represents the representative particle size (micrometer) of the particle | grains which exist in each channel, and n represents the total number of the particle | grains which exist in each channel.)

[Measurement condition]
[1] Particle size range: 100 μm to 8 μm
[2] Channel length (channel width): 2 μm
[3] Number of channels: 46
[4] Refractive index: 2.42

[Analysis by cross-sectional SEM]
Cross section polisher SM-09010 manufactured by JEOL was used for cross-section processing of magnetic carrier particles. Note that in sample preparation, a small amount of magnetic carrier particles are fixed so that each particle exists independently. A sample is set on a table, and processing is performed at a beam current of 140 μA using an Ar ion source with an acceleration voltage of 5 kV, and the sample cross section is cut out.
Note that the magnetic carrier particles used as samples are magnetic carriers satisfying Dw × 0.9 ≦ Dmax ≦ Dw × 1.1, where Dmax is the maximum diameter of each sample.
Further, the position of the plane including the maximum length in the direction parallel to the fixing surface of each sample is set as a distance h from the fixing surface (for example, h = r in the case of a perfect sphere having a radius r). .

A cross section is cut out in a direction perpendicular to the fixing surface within a range of 0.9 × h to 1.1 × h from the fixing surface. The sample whose cross section has been processed can be directly applied to observation with a scanning electron microscope (SEM). In observation with a scanning electron microscope, it is known that the amount of reflected electrons emitted from a sample is larger as a heavy element.
For example, in the case of a sample in which a metal such as an organic compound and an iron element is distributed in a planar shape, the amount of reflected electrons emitted from the iron element is detected more, so the iron element portion is bright on the image ( (Luminance, white). On the other hand, since the amount of reflected electrons from the organic compound composed of the light element compound is small, it appears dark on the image (low brightness and black).

In the cross-sectional observation of the magnetic carrier particle of the present invention, the metal oxide part derived from the magnetic core particle part region is bright (high brightness, white), and the region other than the magnetic core particle part is dark (low brightness, black). ) So that images with large contrast differences can be obtained.
Specifically, it observed on the following conditions using the scanning electron microscope (SEM) and S-4800 (made by Hitachi High-Technologies Corporation).
In addition, it observed after performing flushing operation.
SignalName = SE (U, LA100) AcceleratingVoltage = 5000Volt EmissionCurrent = 10000nA WorkingDistance = 4000μm LensMode = High Condencer1 = 3 ScanSpeed = Slow4 (40sec) Magnification = 1500 DataSize = 1280x960 ColorMode = Grayscale SpecimenBias = 0V
In addition to the above conditions, the reflected electron image is captured by adjusting the brightness to “Contrast 5 and Brightness-5” on the control software of the scanning electron microscope S-4800, setting the magnetic pair observation mode to OFF, and the 256th floor. Toned grayscale image was obtained.

  Specifying the magnetic core particle part region in the cross section of the magnetic carrier particle, and specifying the region other than the magnetic core particle part (resin part and / or void), image analysis of gray scale SEM reflected electron image of the magnetic carrier particle cross section Software Image-ProPlus 5.1J (Media Cybernetics) was used. The processed cross-sectional area of the magnetic carrier particles and the boundary between the background can be easily distinguished from the backscattered electron observation image.

By performing the above, a cross-sectional view of the carrier as shown in FIG. 6 can be obtained. Next, it is divided on the image into an area other than the magnetic core particle part and a magnetic core particle part area. The convex part of this invention can be specified from the outline of the core particle obtained in this way.
FIG. 7 is a diagram schematically showing the outline of the core particle of the present invention. The core particles have large and small protrusions and dents on the surface thereof. The convex part of this invention means the part which specifies the area | region where an area becomes the maximum among the area | regions surrounded by the line which connected the protrusion part of core particle, and contact | connects the outline of the area | region. That is, a bulge that is a relatively small bulge sandwiched between two protrusions and is present on the inner side of the line connecting the vertices of the two protrusions is ignored. In FIG. 7, 1-6 shown with the arrow are the convex parts of this invention.
From the cross-sectional view of the carrier of FIG. 6, the first coat layer is coated on the convex portions of the present invention, and there is a region where the first coat layer is not coated between the adjacent convex portions, and the second coat layer is It can be confirmed that it is coated.
In the present invention, it is desirable that 50% by number of carriers satisfying such conditions be present in 100 carriers, more desirably 60% by number, and even more desirably 70% by number.

  The electrostatic latent image developing carrier of the present invention can supply a stable amount of toner to the electrostatic latent image developing carrier without being affected by the hysteresis even when used for a long period of time. In addition, since an increase in carrier resistance due to toner spent accumulation can be reduced, it can be suitably used as a developer described below.

(Developer)
The developer includes the aforementioned electrostatic latent image developing carrier of the present invention and toner.

<Toner>
The toner contains a binder resin, a charge control agent, and a release agent, and further contains other components as necessary.

-Binder resin-
The binder resin is not particularly limited and may be appropriately selected depending on the intended purpose. For example, styrene such as polystyrene and polyvinyltoluene and a substituted homopolymer thereof, a styrene-p-chlorostyrene copolymer, Styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-methyl methacrylate copolymer Polymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethacrylate methyl copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer Styrene-vinyl methyl ketone copolymer, styrene-butane Styrene binder resins such as ene copolymers, styrene-isoprene copolymers, styrene-maleic acid copolymers, styrene-maleic acid ester copolymers, etc .; polymethyl methacrylate, polybutyl methacrylate, etc. Acrylic binder resin: polyvinyl chloride resin, polyvinyl acetate resin, polyethylene resin, polypropylene resin, polyester resin, polyurethane resin, epoxy resin, polyvinyl butyral resin, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenol resin , Aliphatic or aliphatic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffin, paraffin wax and the like. These may be used individually by 1 type and may use 2 or more types together. Among these, polyester resins are preferable in that the melt viscosity can be further lowered while ensuring the stability of the toner during storage.

--- Polyester resin--
There is no restriction | limiting in particular as said polyester resin, According to the objective, it can select suitably, For example, the resin etc. which are obtained by the polycondensation reaction of an alcohol component and a carboxylic acid component are mentioned, It uses together with crystalline polyester resin May be used.

---- Alcohol component ---
There is no restriction | limiting in particular as said alcohol component, According to the objective, it can select suitably, For example, polyethyleneglycol, diethyleneglycol, triethyleneglycol, 1,2-propyleneglycol, 1,3-propyleneglycol, 1,4 -Diols such as propylene glycol, neopentyl glycol, 1,4-butenediol, 1,4-bis (hydroxymethyl) cyclohexane, bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, polyoxypropylenated bisphenol Etherified bisphenols such as A, divalent alcohol units in which these are substituted with a saturated or unsaturated hydrocarbon group having 3 to 22 carbon atoms, other divalent alcohol units, sorbitol, 1, 2, 3 , 6-hex Tetrol, 1,4-sorbitan, pentaesitol, dipentaerythritol, tripentaerythritol, sucrose, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methyl Examples thereof include trihydric or higher alcohol monomers such as propanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane and 1,3,5-trihydroxymethylbenzene.

--- Carboxylic acid component ---
The carboxylic acid component is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include monocarboxylic acids such as palmitic acid, stearic acid, and oleic acid, maleic acid, fumaric acid, mesaconic acid, and citraconic acid. Terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, malonic acid, divalent organic acid monomers in which these are substituted with a saturated or unsaturated hydrocarbon group having 3 to 22 carbon atoms, these Acid anhydride, dimer acid of lower alkyl ester and linolenic acid, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1, 2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicar Trisyl or higher polyhydric acids such as xyl-2-methyl-2-methylenecarboxypropane, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid embol trimer acid, anhydrides of these acids, etc. Examples thereof include carboxylic acid monomers.

--- Crystalline polyester resin ---
The crystalline polyester resin is a resin added for fixing toner at a low temperature and improving image glossiness at a low temperature. At the same time, the crystalline polyester resin undergoes a crystal transition at the glass transition temperature, and at the same time, rapidly melts from the solid state. Is a resin that exhibits a fixing function to a recording medium such as paper.

  The crystalline polyester resin is represented by the ratio between the softening point and the highest endothermic peak temperature in a differential scanning calorimeter (DSC), that is, the crystallinity index defined by the softening point / the highest endothermic peak temperature. There is no restriction | limiting in particular as said crystallinity index | exponent, Although it can select suitably according to the objective, 0.6-1.5 are preferable and 0.8-1.2 are more preferable.

  As content of the said crystalline polyester resin, 1 mass part-35 mass parts are preferable with respect to 100 mass parts of said polyester resins, and 1 mass part-25 mass parts are more preferable. When the content of the crystalline polyester resin exceeds 35 parts by mass, filming tends to occur on the surface of the image carrier, and storage stability may be deteriorated.

-Charge control agent-
The charge control agent is used for the purpose of sufficiently controlling the triboelectric chargeability of the toner.
The charge control agent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include metal complexes of monoazo dyes, nitrohumic acids and salts thereof, metal salts of salicylic acid and derivatives thereof, naphthoic salts, and dicarboxylic acids. Metal complex amino compounds such as Co, Cr and Fe; quaternary ammonium compounds and organic dyes. These may be used individually by 1 type and may use 2 or more types together. Among these, when using a color toner other than black, a white or transparent charge control agent such as a metal salt of a white salicylic acid derivative is preferable.

-Release agent-
The release agent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, low molecular weight polypropylene, low molecular weight polyethylene, carnauba wax, microcrystalline wax, jojoba wax, rice wax, montanic acid wax Etc. These may be used individually by 1 type and may use 2 or more types together.

-Other ingredients-
There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, For example, an additive, a magnetic body, a coloring agent etc. are mentioned.

--Additives--
The additive is added to impart sufficient fluidity to the toner and obtain a good image.
The additive is not particularly limited and may be appropriately selected depending on the intended purpose.For example, an abrasive, a lubricant, a fluidity-imparting agent, an anti-caking agent, etc. may be mentioned. Examples thereof include elementary organic resin fine particles such as silicon carbide; metal fine particles such as zinc stearate, cerium oxide, hydrophobic silica, and hydrophobic titanium dioxide; metal soap and fluororesin. These may be used individually by 1 type and may use 2 or more types together. Among these, hydrophobic silica is preferable in that sufficient fluidity can be imparted to the toner.

--- Magnetic material--
There is no restriction | limiting in particular as a magnetic body, According to the objective, it can select suitably, For example, ferromagnetic materials, such as iron and cobalt, magnetite, hematite, Li system ferrite, Mn-Zn system ferrite, Cu-Zn system Examples thereof include magnetic materials such as ferrite, Ni-Zn ferrite, and Ba ferrite.

--Colorant--
The colorant is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include iron black, ultramarine blue, carbon black, lamp black, Hansa Yellow G, rhodamine 6G lake, quinacridone, benzidine yellow, and chrome yellow. Rose Bengal, Calco Oil Blue, Aniline Blue, Phthalocyanine Blue, Monoazo Pigment, Triallyl Methane Dye, Nigrosine Dye, Disazo Dye, Dye Pigment, and the like. These may be used individually by 1 type and may use 2 or more types together.

<< Toner Production Method >>
As the method for producing the toner, the binder resin contains the charge control agent, the release agent, the other components, and the like, and is formed into an indefinite shape, a spherical diameter by a conventionally known polymerization method, granulation method, or the like. And the like, and the like.

The toner produced by the toner production method may be a magnetic toner or a non-magnetic toner, or a color toner or a transparent toner.
The magnetic toner is a toner containing the magnetic material.
The nonmagnetic toner is a toner that does not contain the magnetic material.
The color toner is a toner containing the colorant.
The transparent toner is a toner that does not contain the colorant.

-Toner weight average particle diameter Dw-
The weight average particle diameter Dw of the toner refers to a particle diameter at an integrated value of 50% in the particle size distribution of the core particles obtained by a laser diffraction / scattering method. There is no restriction | limiting in particular as the weight average particle diameter Dw of the said toner, Although it can select suitably according to the objective, 3.0 micrometers-9.0 micrometers are preferable, and 3.0 micrometers-6.0 micrometers are more preferable.

  The weight average particle diameter Dw of the toner was measured using a Coulter Multisizer II (manufactured by Beckman Coulter, Inc.). It calculated using the following calculation formula (3). Each channel represents a length for dividing the particle size range in the particle size distribution chart into measurement width units, and the lower limit value of the particle size stored in each channel is adopted as the representative particle size.

（ただし、前記計算式（３）中、Ｄは、各チャネルに存在する粒子の代表粒径（μｍ）を表し、ｎは、各チャネルに存在する粒子の総数を表す。）

(However, in the calculation formula (3), 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.)

[Measurement condition]
[1] Particle size range: 100 μm to 8 μm
[2] Channel length (channel width): 2 μm
[3] Number of channels: 46
[4] Refractive index: 2.42

<Method for producing developer>
The method for producing the developer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the electrostatic latent image developing carrier and the toner are mixed and stirred by a turbuler mixer. The method of manufacturing by this is mentioned.

(Container with developer)
The developer-containing container contains the developer containing the above-described electrostatic latent image developing carrier and toner of the present invention in a container.
The developer-containing container is easy to store and transport, has excellent handleability, and can be suitably used for replenishing the developer by being detachably attached to a process cartridge described later.

There is no restriction | limiting in particular as said container containing a developing agent, A conventionally well-known container can be used according to the objective, For example, it has a container main body and a cap.

  The container body is not particularly limited in size, shape, structure, material, etc., and can be appropriately selected according to the purpose. As the shape, a cylindrical shape is preferable, and as the structure, spiral irregularities are formed on the inner peripheral surface, and the toner as the contents can be transferred to the discharge port side by rotating, and the spiral portion Part or all of the structure preferably has a bellows function, and the material is preferably a polyester resin, polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, polyacrylic acid, polycarbonate resin, ABS resin, polyacetal resin, or the like. .

  There is no restriction | limiting in particular about the magnitude | size, a shape, a structure, a material, etc. as said cap, According to the objective, it can select suitably.

(Replenishment developer)
The replenishment developer includes the aforementioned electrostatic latent image developing carrier of the present invention 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.

  The replenishment developer is not particularly limited as long as it contains 2 to 50 parts by mass of the toner with respect to 1 part by mass of the electrostatic latent image developing carrier. Although it can be selected, it is preferable to contain 5 to 1220 parts by mass of the toner. When the toner is contained in a ratio of less than 2 parts by mass with respect to 1 part by mass of the electrostatic latent image developer carrier, the amount of replenishment carrier is excessive, the carrier is excessively supplied, and the carrier concentration in the developing device is Since it becomes too high, the charge amount of the toner may easily increase. Further, when the toner charge amount increases, the developing ability may decrease and the image density may decrease. When the amount of the toner exceeds 50 parts by mass with respect to 1 part by mass of the electrostatic latent image developer carrier, the ratio of the carrier in the replenishment developer is reduced. Carrier replacement may be reduced, and the effect on carrier deterioration may not be expected.

(Process cartridge)
The process cartridge according to the present invention includes an electrostatic latent image carrier and an electrostatic latent image formed on the electrostatic latent image carrier, the developer including the above-described electrostatic latent image developing carrier and toner according to the present invention. The developing means using the agent is formed so as to be integrally supported.

An embodiment of the process cartridge of the present invention will be described with reference to FIG.
As shown in FIG. 1, the process cartridge (10) includes an electrostatic latent image carrier (11), a charging device (12) for charging the electrostatic latent image carrier, and the electrostatic latent image carrier. A developing device (13) for developing the formed electrostatic latent image using the developer of the present invention to form a toner image, and transferring the toner image formed on the electrostatic latent image carrier to a recording medium After that, it has a cleaning device (14) for removing the toner remaining on the electrostatic latent image carrier and is detachable from the main body of an image forming apparatus such as a copying machine or a printer.

(Image forming apparatus and image forming method)
The image forming apparatus according to the present invention includes a unit for forming an electrostatic latent image on the electrostatic latent image carrier and the electrostatic latent image formed on the electrostatic latent image carrier. A means for developing using a developer including an electrostatic latent image developing carrier and a toner to form a toner image; a means for transferring a toner image formed on the electrostatic latent image carrier to a recording medium; Means for fixing the toner image transferred to the recording medium. The means for forming the toner image is not particularly limited and may be appropriately selected depending on the intended purpose. However, a means for developing using a developer having a magnetic brush to form a toner image is preferable.

  The image forming method of the present invention includes a step of forming an electrostatic latent image on an electrostatic latent image carrier and the electrostatic latent image formed on the electrostatic latent image carrier described above. Developing with a developer containing an electrostatic latent image developing carrier and a toner to form a toner image; transferring the toner image formed on the electrostatic latent image carrier onto a recording medium; Fixing the toner image transferred to the recording medium. The step of forming the toner image is not particularly limited and may be appropriately selected depending on the intended purpose. However, a step of developing using a developer having a magnetic brush to form a toner image is preferable.

An embodiment of the image forming apparatus of the present invention will be described with reference to FIG.
As shown in FIG. 2, first, the electrostatic latent image carrier (20) is rotated at a predetermined peripheral speed, and the peripheral surface of the electrostatic latent image carrier 20 is positive or negative by the charging device (32). Are uniformly charged to a predetermined potential. 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 developer containing the electrostatic latent image developing carrier and toner of the present invention. Development is performed to form a toner image. 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), the images are sequentially transferred onto the transfer paper fed between them. 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 copied as a copy (copy) of the image forming apparatus. Printed out. On the other hand, the surface of the electrostatic latent image carrier (20) after the toner image is transferred is cleaned by removing the residual toner by the cleaning device (60), and then removed by the static eliminator (70). And used repeatedly for image formation.

Hereinafter, typical embodiments of the present invention will be described as follows, but the present invention is not limited to these examples.
In the following description, “parts” and “%” mean “parts by weight” and “% by weight” unless otherwise specified.
Further, the shape factor SF-1, the shape factor SF-2, the arithmetic average surface roughness Ra, the powder specific resistance value of the filler, the weight average particle size of the core particles, and the average particle size of the fillers measured in Examples and Comparative Examples The diameter and the average particle diameter of the toner are values obtained by measurement by the measurement method described above.

<Manufacture of core particles>
[Core Particle Production Example 1: Production of Core Particle 1]
MnCO ₃ , Mg (OH) ₂ , Fe ₂ O ₃ , and SrCO ₃ powder were weighed so as to have the following component composition and mixed to obtain a mixed powder. This mixed powder was temporarily fired in a heating furnace at 840 ° C. for 1 hour in the air atmosphere, and the obtained temporarily fired product was cooled and pulverized to obtain a powder having an average particle diameter of 3 μm. To this powder, a dispersant (1% by mass), which is a water-soluble polymer material, and water are added to form a slurry. This slurry is supplied to a spray dryer and granulated to obtain a granulated product having an average particle size of about 40 μm. Obtained. This granulated product was loaded into a firing furnace and fired at 1110 ° C. for 3 hours in a nitrogen atmosphere. The obtained fired product was pulverized with a pulverizer, and the particle size was adjusted by sieving to obtain [core particle 1] (spherical ferrite particle) having a weight average particle size of about 35 μm. When the component analysis of this [core particle 1] was performed, it was MnO (40.0 mol%), MgO (10.1 mol%), Fe2O3 (50 mol%), SrO (0.4 mol%) as originally targeted. . [Core particle 1] had SF-1 of 145, SF-2 of 119, Ra of 0.98 μm, and a bulk density of 2.0.

[Core Particle Production Example 2: Production of Core Particle 2]
Without pre-firing in the core particle production example 1, the slurry was supplied to a spray dryer and granulated to obtain a granulated product having an average particle size of about 40 μm. This granulated product was loaded into a firing furnace and fired at 1,300 ° 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 [Core Particle 2] (spherical ferrite particle) having a weight average particle size of about 35 μm. SF-1 of this [core particle 2] was 125, SF-2 was 119, Ra was 0.51 μm, and the bulk density was 2.4.

[Core Particle Production Example 3: Production of Core Particle 3]
The core particle production example 2 was carried out in the same manner except that it was calcined at 1,350 ° C. for 5 hours in a nitrogen atmosphere to obtain [core particle 3] (spherical ferrite particle) having a weight average particle diameter of about 35 μm. SF-1 of this [core particle 3] was 120, SF-2 was 111, Ra was 0.50 μm, and the bulk density was 2.4.

[Core Particle Production Example 4: Production of Core Particle 4]
MnCO ₃ , Mg (OH) ₂ , Fe ₂ O ₃ , and SrCO ₃ powder were weighed to have the following component composition to obtain a powder having an average particle size of 3 μm. A dispersant (1% by mass) and water were added to this 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. This granulated product was loaded into a firing furnace and fired at 1250 ° 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 [core particles 4] (spherical ferrite particles) having a weight average particle size of about 35 μm. When the component analysis of this [core particle 4] was conducted, they were MnO (46.2 mol%), MgO (0.7 mol%), and Fe2O3 (53 mol%) as originally targeted. Moreover, SF-1 of [core particle 4] was 130, SF-2 was 128, Ra was 0.45 μm, and the bulk density was 2.4.

<Conductive fine particles>
[Conductive Fine Particle Production Example 1: Production of Conductive Fine Particle 1]
100 g of aluminum oxide (AKP-30, manufactured by Sumitomo Chemical Co., Ltd.) was dispersed in 1 L of water to form a suspension, and heated to 70 ° C. Next, a solution of 150 g of stannic chloride and 4.5 g of phosphorus pentoxide in 1.5 L of 2N hydrochloric acid and 12% by mass of ammonia water over 3 hours so that the pH of this suspension is 7-8. It was dripped. After dropping, the cake obtained by filtering and washing the suspension was dried at 110 ° C. Then, this dry powder was treated in a nitrogen stream at 500 ° C. for 1 hour to obtain [conductive fine particles 1]. The obtained [Conductive fine particles 1] had an average particle diameter of 600 nm and a volume resistivity of 10 Ω · cm.

[Conductive fine particle example 2]
EC-700 (particle size: 350 nm, manufactured by Titanium Industry Co., Ltd.) was adopted as the conductive fine particles 2 to produce a carrier.

[Conductive fine particle example 3]
As the conductive fine particles 3, an oxygen-deficient tin oxide-coated barium sulfate powder (manufactured by Mitsui Metals, trade name: Pastorran 4310, particle size: 100 nm) was used to produce a carrier.

[Example 4 of conductive fine particles]
A carrier was manufactured using S-2000 (Gemco particle size: 30 nm) as the conductive fine particles 4.

[Example 5 of conductive fine particles]
A carrier was manufactured using AA03 (particle size: 350 nm, manufactured by Titanium Industry Co., Ltd.) as the conductive fine particles 5.

<Synthesis of copolymer>
[Resin 1]
The weight average molecular weight was determined in terms of standard polystyrene using gel permeation chromatography. The viscosity was measured at 25 ° C. according to JIS-K2283. The non-volatile content was calculated according to the following formula by weighing 1 g of the coating composition in an aluminum dish and measuring the weight after heating at 150 ° C. for 1 hour.
Non-volatile content (%) = (weight before heating−weight after heating) × 100 / weight before heating

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-methacryloxypropyltris (trimethylsiloxy) silane 84. represented by CH ₂ = CMe—COO—C ₃ H ₆ —Si (OSiMe ₃ ) ₃ (wherein Me is a methyl group). 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′- A mixture of 0.58 g (3 mmol) of azobis-2-methylbutyronitrile 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-methylbutyrate). A total amount of ronitrile (0.64 g = 3.3 mmol) was mixed at 90 to 100 ° C. for 3 hours and radical copolymerized to obtain a methacrylic copolymer.
The weight average molecular weight of the obtained methacrylic copolymer was 33,000. Subsequently, it diluted with toluene so that the non volatile matter of this methacrylic copolymer solution might be 25 weight%. The viscosity of the copolymer solution thus obtained was 8.8 mm ² / s, and the specific gravity was 0.91.

[Resin 2]
As the resin 2, a silicon resin solution [solid content: 20% by weight] (SR2410: manufactured by Toray Dow Corning Silicone) was used.

<Coating solution application process>
The coating liquid application method was examined in three types: the above-described apparatus A, apparatus B, and the state before changing the height of apparatus A (referred to as apparatus C for convenience).

<Manufacture of carriers>
[Example 1: Production of carrier A]
(I) First coat layer / resin 1 [solid content 25% by weight] 3.3 parts by weight Resin 2 [solid content 20% by weight] 36.7 parts by weight aminosilane [solids content 100% by weight] 0.8% by weight (SH6020: manufactured by Toray Dow Corning Silicone)]
-Conductive fine particles None-Toluene 13.5 parts by weight together with 1000 parts of 0.5 mm Zr beads was dispersed for 1 hour with a paint shaker, and then the beads were removed with a mesh to obtain a resin coating film forming solution. Using the above-mentioned [core particle 1]: 5000 parts by weight as a core material, a solution obtained by adding 1.9 parts by weight of TC-750 (manufactured by Matsumoto Fine Chemical Co., Ltd.) [solid content 60% by weight] to the above coating film forming solution. The surface of the core particles was coated with the apparatus A at a coater temperature of 75 ° C. and dried. The obtained carrier was baked by being left in an electric furnace at 280 ° C. for 1 hour in a nitrogen atmosphere. After cooling, the ferrite powder bulk was crushed using a sieve having an aperture of 63 μm.

(Ii) Second coat layer / resin 1 [solid content 25% by weight] 54.4 parts by weight Resin 2 [solid content 20% by weight] 612.2 parts by weight aminosilane [solids content 100% by weight] 14.1% by weight (SH6020: manufactured by Toray Dow Corning Silicone)
-Conductive fine particles 2 250.0 parts by weight-Toluene 238.5 parts by weight with a 0.5 mm Zr bead 1000 parts and dispersed with a paint shaker for 1 hour, then the beads are removed with a mesh to obtain a resin coating film forming solution It was. Carrier obtained in the first coat layer as a core material: 5000 parts by weight, and 33.2 parts by weight of TC-750 (manufactured by Matsumoto Fine Chemical Co., Ltd.) [solid content 60% by weight] was added to the coating film forming solution. The solution was applied to the surface of the core particles by the apparatus C at a coater internal temperature of 75 ° C. and dried. The obtained carrier was baked by standing at 230 ° C. for 1 hour in an electric furnace under a nitrogen atmosphere. After cooling, the ferrite powder bulk was crushed using a sieve having an aperture of 63 μm to obtain [Carrier A].

[Example 2: Production of carrier B]
Coating method shown in Tables 1 and 2 using the core material, resin (resin 1 and resin 2), conductive fine particles, and silane coupling agent shown in Tables 1 and 2 by the method according to Example 1. In the firing step, the first coat layer and the second coat layer were provided on the core material to produce carrier B.

[Example 3: Production of carrier C]
Coating method shown in Tables 1 and 2 using the core material, resin (resin 1 and resin 2), conductive fine particles, and silane coupling agent shown in Tables 1 and 2 by the method according to Example 1. The carrier C was manufactured by providing the first coat layer and the second coat layer on the core material in the firing step.

[Example 4: Production of carrier D]
Coating method shown in Tables 1 and 2 using the core material, resin (resin 1 and resin 2), conductive fine particles, and silane coupling agent shown in Tables 1 and 2 by the method according to Example 1. The carrier D was manufactured by providing the first coat layer and the second coat layer on the core material in the firing step.

[Example 5: Production of carrier E]
Coating method shown in Tables 1 and 2 using the core material, resin (resin 1 and resin 2), conductive fine particles, and silane coupling agent shown in Tables 1 and 2 by the method according to Example 1. The carrier E was manufactured by providing the first coat layer and the second coat layer on the core material in the firing step.

[Example 6: Production of carrier F]
Coating method shown in Tables 1 and 2 using the core material, resin (resin 1 and resin 2), conductive fine particles, and silane coupling agent shown in Tables 1 and 2 by the method according to Example 1. The carrier F was manufactured by providing the first coat layer and the second coat layer on the core material in the firing step.

[Example 7: Production of carrier G]
Coating method shown in Tables 1 and 2 using the core material, resin (resin 1 and resin 2), conductive fine particles, and silane coupling agent shown in Tables 1 and 2 by the method according to Example 1. In the firing step, the first coat layer and the second coat layer were provided on the core material, and the carrier G was manufactured.

[Example 8: Production of carrier H]
Coating method shown in Tables 1 and 2 using the core material, resin (resin 1 and resin 2), conductive fine particles, and silane coupling agent shown in Tables 1 and 2 by the method according to Example 1. The carrier H was manufactured by providing the first coat layer and the second coat layer on the core material in the firing step.

[Example 9: Production of carrier J]
Coating method shown in Tables 1 and 2 using the core material, resin (resin 1 and resin 2), conductive fine particles, and silane coupling agent shown in Tables 1 and 2 by the method according to Example 1. In the firing step, the first coat layer and the second coat layer were provided on the core material to produce carrier J.

[Example 10: Production of carrier K]
Coating method shown in Tables 1 and 2 using the core material, resin (resin 1 and resin 2), conductive fine particles, and silane coupling agent shown in Tables 1 and 2 by the method according to Example 1. The carrier K was manufactured by providing the first coat layer and the second coat layer on the core material in the baking step.

[Comparative Example 1: Production of Carrier L]
Coating method shown in Tables 1 and 2 using the core material, resin (resin 1 and resin 2), conductive fine particles, and silane coupling agent shown in Tables 1 and 2 by the method according to Example 1. In the firing step, the first coat layer and the second coat layer were provided on the core material, and the carrier L was manufactured.

[Comparative Example 2: Production of Carrier M]
Coating method shown in Tables 1 and 2 using the core material, resin (resin 1 and resin 2), conductive fine particles, and silane coupling agent shown in Tables 1 and 2 by the method according to Example 1. The carrier M was manufactured by providing the first coat layer and the second coat layer on the core material in the firing step.

[Comparative Example 3: Production of Carrier N]
Coating method shown in Tables 1 and 2 using the core material, resin (resin 1 and resin 2), conductive fine particles, and silane coupling agent shown in Tables 1 and 2 by the method according to Example 1. In the baking process, the first coat layer and the second coat layer were provided on the core material, and the carrier N was manufactured.

[Comparative Example 4: Production of Carrier P]
Coating method shown in Tables 1 and 2 using the core material, resin (resin 1 and resin 2), conductive fine particles, and silane coupling agent shown in Tables 1 and 2 by the method according to Example 1. In the firing step, the first coat layer and the second coat layer were provided on the core material, and the carrier P was manufactured.

[Comparative Example 5: Production of carrier Q]
Coating method shown in Tables 1 and 2 using the core material, resin (resin 1 and resin 2), conductive fine particles, and silane coupling agent shown in Tables 1 and 2 by the method according to Example 1. In the firing step, the first coat layer and the second coat layer were provided on the core material to produce carrier Q.

[Comparative Example 6: Production of carrier R]
Coating method shown in Tables 1 and 2 using the core material, resin (resin 1 and resin 2), conductive fine particles, and silane coupling agent shown in Tables 1 and 2 by the method according to Example 1. In the baking process, the first coat layer and the second coat layer were provided on the core material, and the carrier R was manufactured.

[Comparative Example 7: Production of carrier S]
The first coat layer is not provided, and the core material, resin (resin 1 and resin 2), conductive fine particles, and silane coupling agent shown in Table 1 and Table 2 are used according to the method according to Example 1, and Table 1 is used. In the coating process and the firing process shown in Table 2, only the second coat layer was provided on the core material, and the carrier S was manufactured.

[Comparative Example 8: Production of carrier T]
The first coat layer is not provided, and the core material, resin (resin 1 and resin 2), conductive fine particles, and silane coupling agent shown in Table 1 and Table 2 are used according to the method according to Example 1, and Table 1 is used. In the coating step and the firing step shown in Table 2, only the second coat layer was provided on the core material, and the carrier T was manufactured.

[Comparative Example 9: Production of carrier U]
The first coat layer is not provided, and the core material, resin (resin 1 and resin 2), conductive fine particles, and silane coupling agent shown in Table 1 and Table 2 are used according to the method according to Example 1, and Table 1 is used. In the coating process and the firing process shown in Table 2, only the second coat layer was provided on the core material, and the carrier U was manufactured.

(Development of developer)
[Carrier A] to [Carrier U] (930 parts by mass) obtained in Examples and Comparative Examples and a toner (70 parts by mass) for a commercially available digital full-color printer (RICOH Pro C901, manufactured by Ricoh Company) were mixed. Then, the developer for evaluation was prepared by stirring for 5 minutes at 81 rpm using a Turbuler mixer. The replenishment developer was prepared using the carrier and the toner so that the toner concentration was 10% by mass.

(Evaluation)
The carriers for developing electrostatic latent images obtained in Examples and Comparative Examples were evaluated. The results are shown in Tables 3 and 4.

<Print evaluation>
Each produced developer and each supplied 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 8% (size of one character; about 2 mm × 2 mm) After printing 50,000 sheets, another 100,000 sheets were printed.

<Evaluation of the effects of historical phenomena>
In order to evaluate the influence of the history phenomenon, after printing 50,000 sheets in the print evaluation, the vertical band chart shown in FIG. 5 was printed. Then, the influence of the immediately preceding image history was evaluated by measuring the density difference between one round (a) and one round (b) of the sleeve (toner carrier). For the measurement, a color value measuring device (X-Rite 938, manufactured by X-Rite) was used. The average density difference obtained by measuring the center, rear, and front of the sleeve at three locations was defined as ΔID, and evaluated according to the following evaluation criteria. The smaller the value of ΔID, the smaller the influence of the history of the previous image, and “◎: very good” and “○: good” are passed, “Δ: unacceptable”, “×: practical use”. “Unable to level” was rejected.
In addition, “△ to ○” was given as acceptable if the test results in ◯ or △.
[Evaluation criteria]
A: ΔID ≦ 0.01
○: 0.01 <ΔID ≦ 0.03
Δ: 0.03 <ΔID ≦ 0.06
×: 0.06 <ΔID

<Evaluation of resistance change of electrostatic latent image developing carrier>
The difference between the resistance value of the electrostatic latent image developing carrier in the developer at the time of printing 50,000 sheets and the resistance value of the electrostatic latent image developing carrier in the developer at the time of printing 150,000 sheets is measured. The resistance change of was evaluated. As shown in FIG. 3, the measurement was carried out using a blow-off cage (7) having a mesh of 795 mesh and an electrostatic latent image developing carrier (3) obtained by sucking and removing the toner (5) from the developer. Further, as shown in FIG. 4, the resistance value of the electrostatic latent image developing carrier is measured from a fluororesin container containing electrodes (1a) and (1b) having a distance between electrodes of 2 mm and a surface area of 2 × 4 cm. The cell is filled with the electrostatic latent image developing carrier (3), a DC voltage of 1,000 V is applied between the two electrodes, and a DC resistance is applied with a high resistance meter (4329A + LJK 5HVLVWDQFH OHWHU, produced by Yokogawa Hewlett-Packard). Measured and calculated ΔLogR at the time of printing 0 sheets. In addition, “◎: very good”, “◯: good”, “Δ: acceptable” were accepted, and “×: level that was not practically usable” was rejected.
[Evaluation criteria]
A: ΔLogR ≦ 0.4
○: 0.4 <ΔLogR ≦ 0.7
Δ: 0.7 <ΔLogR ≦ 1.3
×: 1.3 <ΔLogR

<Carrier adhesion>
Carrier adhesion (solid part)
When carrier adhesion occurs, it may cause damage to the photosensitive drum and the fixing roller, resulting in a decrease in image quality. Even if carrier adhesion occurs on the photoconductor, only a part of the carrier is transferred to the paper, and thus evaluation was made by the following method. It is an evaluation of the developer when printing 150,000 sheets.
Adhered to a solid image (30 mm × 30 mm) under the development conditions described above (charge potential (Vd): −600 V, potential after exposure of a portion corresponding to an image portion (solid original): −100 V, development bias: DC −500 V). The number of carriers was counted on the photoconductor to evaluate solid carrier adhesion.
The symbols described in the table are ◎: very good, ○: good, Δ: unusable, x: poor.

  The cross-sectional photograph observation was implemented about each carrier particle of the carrier A-the carrier U of the said Example and comparative example. The results are shown in the following table.

  As described above, by using the produced electrostatic latent image developing carrier of the present invention, a stable toner amount can be obtained for electrostatic latent image developing without being affected by a hysteresis phenomenon even when continuously used for a long period of time. It was found that the increase in carrier resistance due to toner spent deposition can be reduced.

DESCRIPTION OF SYMBOLS 1a Electrode 1b Electrode 2 Fluororesin 3 Electrostatic latent image developing carrier 5 Toner 7 Brokerage 10 Process cartridge 11 Photoconductor 12 Charging device 13 Developing device 14 Cleaning device 20 Electrostatic latent image carrier 32 Charging device 33 Exposure device 40 Developing device 50 Transfer device 60 Cleaning device 70 Static elimination device 100 Image forming device

JP 2007-25893 A Japanese Patent No. 3356948 JP 2005-157002 A JP 11-231652 A Japanese Patent Application Laid-Open No. 07-072733 Japanese Patent Application Laid-Open No. 07-128983 Japanese Patent Application Laid-Open No. 07-092813 Japanese Patent Laid-Open No. 11-065247 JP 2007-272165 A JP 2007-61730 A

Claims (10)

  A carrier for developing an electrostatic latent image comprising carrier particles including magnetic core particles and a coating layer covering the core particles, the first coat layer comprising a resin component with respect to the core particles; And having a second coat layer containing a filler in the resin, the first coat layer being coated at least on the protrusions with respect to the core particles, and having an uncoated region between adjacent protrusions. A carrier for developing an electrostatic latent image. The shape factor SF-2 of the core particles is 120 to 160,
2. The electrostatic latent image developing carrier according to claim 1, wherein the arithmetic average surface roughness Ra of the core particles is 0.5 μm to 1.0 μm. The carrier for developing an electrostatic latent image according to claim 1 or 2, wherein the existence probability of carrier particles satisfying the following conditions is 50% by number or more.
-In cross-sectional SEM observation, there is no filler in the range of radius 0.1um with respect to the convex part.
-At the time of cross-sectional SEM observation, a filler exists in the range of radius 0.3um with respect to the recessed part of one core material grain.   4. The electrostatic latent image developing carrier according to claim 1, wherein the filler has a particle diameter of 100 nm to 500 nm.   5. The electrostatic latent image developing carrier according to claim 1, wherein the filler is contained in a range of 50 to 500 parts by mass with respect to 100 parts by mass of the resin. The resin hydrolyzes a copolymer containing at least the A part represented by the following general formula (A) and the B part represented by the following general formula (B) to produce a silanol group for condensation. The electrostatic latent image developing carrier according to any one of claims 1 to 5, which contains a cross-linked product obtained by the following process.

(However, in 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 represents an integer of 1 to 8, and X represents Represents 10 mol% to 90 mol%.)

(In 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, and R ³ represents an alkyl group having 1 to 8 carbon atoms or C represents an alkoxy group having 1 to 4 carbon atoms, m represents an integer of 1 to 8, and Y represents 10 mol% to 90 mol%.)   A two-component developer for developing an electrostatic latent image, comprising the carrier for developing an electrostatic latent image according to claim 1 and a toner.   The electrostatic latent image carrier and the means for developing the electrostatic latent image formed on the electrostatic latent image carrier using the developer according to claim 7 are integrally supported. Feature process cartridge.   A means for forming an electrostatic latent image on the electrostatic latent image carrier and an electrostatic latent image formed on the electrostatic latent image carrier using the developer according to claim 7 to develop toner Comprising: means for forming an image; means for transferring a toner image formed on the electrostatic latent image carrier to a recording medium; and means for fixing the toner image transferred to the previous recording medium. Image forming apparatus.   The image forming apparatus according to claim 9, wherein the means for forming the toner image is a means for developing using a developer having a magnetic brush to form a toner image.

Images