JP5504822B2 - Electrophotographic carrier, electrophotographic developer, image forming method, image forming apparatus, process cartridge, and container containing electrophotographic developer - Google Patents

Description

  The present invention relates to an electrophotographic carrier, an electrophotographic developer using the carrier, an image forming method, an image forming apparatus, a process cartridge, and a container containing an electrophotographic developer.

  In recent years, printing apparatuses using an electrophotographic method have been rapidly colorized and the printing speed has been increased. Conventionally, the two-component development method has been widely used in full-color image forming apparatuses because it is suitable for high-speed printing and can easily handle non-magnetic toner. However, the full-color image apparatus needs to include a plurality of developing devices in the apparatus, and has disadvantages such as an increase in the size and weight of the apparatus as compared with a monochrome machine. In particular, the two-component developing device needs to have an electrophotographic developer storage volume and a stirring mechanism in addition to the toner, compared to the one-component developing device. It was essential to reduce the amount of developer for use.

  The electrophotographic carrier in the electrophotographic developer is subjected to mechanical friction and impact by the friction with the toner in the developing device, the rubbing member such as a sleeve and a blade, the regulating member and the stirring and conveying member such as a screw and a paddle. I have received it repeatedly. Reducing the amount of electrophotographic developer means an increase in the chance of friction between the toner and the electrophotographic carrier per printed sheet, and an increase in the frequency with which the electrophotographic carrier passes through the developing section. The fatigue of the electrophotographic carrier rapidly progresses. Combined with increased printing speed, the durability of the electrophotographic carrier, especially the high abrasion resistance of the electrophotographic carrier surface layer, and the contamination of the electrophotographic carrier surface by toner and other components (spent) are prevented. Maintaining rapid chargeability over a long period of time has become more important than ever.

  In recent digital copying machines and printers, negative-positive development is often performed using a negatively charged photoconductor, and negatively charged toner is often used. Many examples are known in which an organic compound containing nitrogen is contained in an electrophotographic carrier film in order to negatively charge the toner. For example, an example in which an aminosilane coupling agent is mixed with a silicone resin (Patent Document 1), a method using an amino compound such as melamine or guanamine or a derivative thereof (Patent Document 2), an acrylic copolymer having an amino group And the like (Patent Document 3), and a method using crosslinked resin fine particles such as melamine (Patent Document 4) are known.

  However, the durability of these electrophotographic carriers is still insufficient, and the toner is spent on the surface of the electrophotographic carrier, resulting in instability of the charge amount, reduction of the coating layer due to film scraping of the coating layer, and The accompanying resistance reduction is a problem, and a good image can be obtained in the initial stage. However, as the number of copies increases, the image quality of the copied image decreases. In addition, since the charge imparting ability to the toner is adjusted by adjusting the amount of the nitrogen-containing organic compound, there is a problem that side effects such as deterioration of the durability of the electrophotographic carrier occur.

  In order to suppress the spent on the surface of the electrophotographic carrier of the toner, attempts have been made to prevent it by using a resin having a low surface energy such as a silicone resin. However, the silicone resin is not only a toner but also an electrophotographic carrier. Since the adhesion to the core material is also reduced, the spent is suppressed, but the peeling of the coating layer made of silicone resin from the core material is promoted to cause a decrease in resistance due to the core material exposure. Further, when a low surface energy resin is used in combination with another resin, there is a problem that the composition of the surface of the electrophotographic carrier tends to be non-uniform because of low compatibility with each other.

  In order to solve such problems, for example, an electrophotographic carrier having a coating layer obtained by a polymerization reaction of at least one isocyanate compound with water and silicone or a fluorine-based amine compound on a core material has been proposed. (See Patent Document 5). According to this, it is disclosed that silicone and fluorine components with low surface energy but weak durability can be uniformly present inside the resin, and the mechanical strength can be improved by controlling the degree of crosslinking and the spent resistance can also be improved. Has been.

  However, although the electrophotographic carrier can improve the uniformity of the coating resin and prevent image quality deterioration due to the toner spent, it still has insufficient mechanical strength and is due to stress during stirring of the electrophotographic developer. There was a problem that the coating layer was easily deteriorated, and in particular, film abrasion due to insufficient mechanical strength of the coating layer was likely to occur.

  In addition, as a method for improving the adhesion of the resin coating layer of the electrophotographic carrier, there is a study of providing a resin layer having a novolak structure with excellent adhesiveness as the lowermost coating layer of at least two coating layers. (See Patent Document 6).

  However, although the above method suppresses the peeling of the coating layer due to stress, the outer layer resin improves the adhesion by giving affinity to the novolac resin, and therefore, styrene acrylic or polyester is preferable. There has been a problem that it is difficult to positively use a low surface energy resin such as a silicone resin having a low affinity for the resin. Furthermore, the coating layer having a multilayer structure means that the composition of the outermost layer of the electrophotographic carrier changes when the abrasion of the coating layer exceeds a certain level, and the toner as an electrophotographic developer is changed. This causes a large change in the charging behavior, which is not preferable from the viewpoint of extending the life.

  Thus, the present situation is that further improvement is required in order to achieve a long life while pursuing high image quality by stabilizing charging in the developer for electrophotography.

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, the present invention provides an electrophotographic carrier having a coating layer in which the charge amount can be adjusted within a desired range without causing problems of image quality degradation due to toner spent or surface wear, toner scattering, and background contamination. An object is to provide an electrophotographic developer using an electrophotographic carrier, an image forming method, an image forming apparatus, a process cartridge, and a container containing an electrophotographic developer.

  As a result of intensive studies by the present inventors in order to solve the above-mentioned problems, the coating layer containing at least a binder resin precursor and a solvent has (A) a diisocyanate compound and (B) two different chain lengths. By containing the above-mentioned amino group-modified polysiloxane and (C) a polyfunctional epoxy resin that is at least one of a phenol novolak type epoxy resin, a cresol novolak type epoxy resin, and a derivative thereof, the toner spent or surface wear is caused. The present inventors have found that the problem that the charge amount can be adjusted within a desired range can be solved without causing problems of image quality degradation, toner scattering, and background contamination, and the present invention has been completed.

The present invention is based on the above findings by the present inventors, and means for solving the above problems are as follows. That is,
<1> An electrophotographic carrier having a core material, and a coating layer containing at least a binder resin precursor and a solvent on the surface of the core material,
The binder resin precursor contains at least (A) a diisocyanate compound, (B) an amino group-modified polysiloxane represented by the following general formula (1), and (C) a polyfunctional epoxy resin. This is a carrier for electrophotography.
_{NH 2 (CH 2) 3 (} R 2 SiO) n SiR 2 (CH 2) 3 NH 2 Formula (1)
However, in the said General formula (1), R is a hydrogen atom, a halogen atom, a C1-C10 alkoxy group or an allyloxy group, a C1-C20 saturated hydrocarbon group, a C2-C20 alkenyl group. , An aralkyl group having 6 to 20 carbon atoms, an aryl group having 7 to 20 carbon atoms, a silicon atom-containing group having 1 to 10 silicon atoms, and a substituent thereof, which may be the same as each other, May be different. n represents the calculated chain length calculated from the molecular weight.
<2> (C) The electrophotographic carrier according to <1>, wherein the polyfunctional epoxy resin is at least one of a phenol novolac epoxy resin, a cresol novolac epoxy resin, and a derivative thereof.
<3> The content ratio (mc) of the (C) polyfunctional epoxy resin is a mass ratio (mc /) to the total content (mT) of the (A) diisocyanate compound and (B) both-terminal amino group-modified polysiloxane. The electrophotographic carrier according to any one of <1> to <2>, wherein mT) is 0.005 to 0.1.
<4> (B) For electrophotography according to any one of <1> to <3>, wherein the both-end amino group-modified polysiloxane is two or more kinds of both-end amino group-modified polysiloxanes having different chain lengths n. It is a career.
<5> For electrophotography according to any one of <1> to <4>, wherein the chain length n calculated from the mass average molecular weight of the amino group-modified polysiloxane represented by the general formula (1) is 10 or less. Is a career.
<6> The electrophotographic carrier according to any one of <1> to <5>, wherein the coating layer contains fine particles.
<7> An electrophotographic developer comprising the electrophotographic carrier according to any one of <1> to <6> and a toner.
<8> The electrophotographic developer according to <7>, wherein the toner charge amount is −10 μc / g to −50 μc / g when the coverage of the electrophotographic carrier with the toner is 50%.
<9> an electrostatic latent image forming step of forming an electrostatic latent image on the surface of the electrostatic latent image carrier;
A development step of developing the electrostatic latent image formed on the surface of the electrostatic latent image carrier using a developer to form a visible image;
A transfer step of transferring the visible image to a recording medium;
A fixing step of fixing the visible image transferred to the recording medium;
An electrophotographic image forming method comprising: the electrophotographic developer according to any one of <7> to <8>.
<10> an electrostatic latent image carrier;
An electrostatic latent image forming means for forming an electrostatic latent image on the surface of the electrostatic latent image carrier;
Developing means for developing an electrostatic latent image formed on the surface of the electrostatic latent image carrier with an electrophotographic developer to form a visible image;
Transfer means for transferring the visible image to a recording medium;
Fixing means for fixing the visible image transferred to the recording medium;
An electrophotographic image forming apparatus comprising: the electrophotographic developer according to any one of <7> to <8>. It is.
<11> an electrostatic latent image carrier;
Developing means for developing an electrostatic latent image formed on the surface of the electrostatic latent image carrier using an electrophotographic developer to form a visible image;
A process cartridge for an electrophotographic image forming apparatus, wherein the electrophotographic developer is the electrophotographic developer according to any one of <7> to <8>. It is.
<12> The electrophotographic apparatus according to any one of <7> to <8>, wherein the image forming apparatus according to <10> and the process cartridge according to <11> are removable. An electrophotographic developer-containing container characterized by containing a developer.

  According to the present invention, the above-described problems can be solved and the object can be achieved, and within a desired range without causing image degradation due to toner spent or surface wear, toner scattering, and background contamination. Electrophotographic carrier having coating layer capable of adjusting charge amount, electrophotographic developer, image forming method, image forming apparatus, process cartridge, and electrophotographic developer container using this electrophotographic carrier Can be provided.

FIG. 1 is a schematic view of an apparatus for measuring the charge amount of an electrophotographic developer. FIG. 2 is a schematic configuration diagram showing an example of a process cartridge used in the present invention. FIG. 3 is a schematic explanatory view showing an example in which the image forming method of the present invention is carried out by the image forming apparatus. FIG. 4 is a schematic explanatory view showing another example in which the image forming method of the present invention is carried out by the image forming apparatus. FIG. 5 is a schematic explanatory view showing an example in which the image forming method of the present invention is carried out by an image forming apparatus (tandem color image forming apparatus). 6 is a partially enlarged schematic explanatory view of the image forming apparatus shown in FIG.

(Electrophotographic carrier)
The electrophotographic carrier of the present invention comprises a core material and a coating layer.

<Core>
The material for the core material is not particularly limited and can be appropriately selected according to the purpose from known ones as two-component electrophotographic carriers for electrophotography. Examples thereof include ferrite, magnetite, iron, nickel and the like. Preferably mentioned. Moreover, in consideration of environmental aspects that have been remarkably advanced in recent years, if it is ferrite, it is not a conventional copper-zinc ferrite, for example, Mn ferrite, Mn-Mg ferrite, Mn-Mg-Sr ferrite, copper-zinc Ferrite, lithium ferrite and the like can also be used.

  In addition, the said core material is Li, Na, K, Ca, Ba, Y as a composition component of other core materials from the objective of controlling core resistance, and the objective of improving manufacturing stability, etc. as needed. , Ti, Zr, V, Ag, Ni, Cu, Zn, Al, Sn, Sb, Bi and the like may be mixed in one or more kinds. As these compounding quantities, it is preferable that it is 5 atomic% or less of the total amount of metal elements, and it is more preferable that it is 3 atomic% or less.

  As the volume average particle diameter of the core material, the volume average particle diameter is preferably 20 μm or more from the viewpoint of preventing the electrophotographic carrier from adhering (scattering) to the electrostatic latent image carrier, such as an electrophotographic carrier stripe. 100 μm or less is more preferable from the viewpoint of preventing image quality deterioration such as generation prevention, and 20 μm to 50 μm is particularly preferable for the recent improvement in image quality.

  The volume average particle diameter of the core material can be measured, for example, by using “Microtrac particle size analyzer SRA, manufactured by Nikkiso Co., Ltd.” with a range setting of 0.7 μm to 125 μm.

<Coating layer>
The coating layer is formed on the surface of the core material particles using a coating layer solution.

The coating layer solution includes at least a binder resin precursor and a solvent, and the binder resin precursor includes at least (A) a diisocyanate compound and (B) both ends represented by the following general formula (1). It contains an amino group-modified polysiloxane and (C) a polyfunctional epoxy resin, and further contains other components as necessary.
_{NH 2 (CH 2) 3 (} R 2 SiO) n SiR 2 (CH 2) 3 NH 2 Formula (1)
However, in the said General formula (1), R is a hydrogen atom, a halogen atom, a C1-C10 alkoxy group or an allyloxy group, a C1-C20 saturated hydrocarbon group, a C2-C20 alkenyl group. , An aralkyl group having 6 to 20 carbon atoms, an aryl group having 7 to 20 carbon atoms, a silicon atom-containing group having 1 to 10 silicon atoms, and a substituent thereof, which may be the same as each other, May be different. n represents the calculated chain length calculated from the molecular weight.

  The coating layer liquid is cross-linked by applying a coating liquid (coating liquid) containing a binder resin precursor and a solvent to an electrophotographic carrier core material in a later-described process, followed by a heating process. Thus, it is possible to form a finally strong coating layer having an appropriate electric resistance value on the surface of the electrophotographic carrier.

<< (A) component >>
Examples of the diisocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, modified diphenylmethane diisocyanate (modified MDI), hydrogenated xylylene diisocyanate (H-XDI), xylylene diisocyanate (XDI), hexamethylene diisocyanate (HMDI), trimethyl. Hexamethylene diisocyanate (TMHMDI), tetramethylxylylene diisocyanate (m-TMXDI), isophorone diisocyanate (IPDI), norbornene diisocyanate (NBDI), 1,3-bis (isocyanatomethyl) cyclohexane (H6XDI), 1,5-naphthalene And diisocyanate. These isocyanate compounds may be used individually by 1 type, and may use 2 or more types together. Moreover, you may use the blocked isocyanate which blocked some or all of the isocyanate group using well-known blocking agents, such as a phenol compound and oximes.

<< (B) component >>
The said both terminal amino group modified polysiloxane has a structure represented by the said General formula (1), As a commercial item, for example, PAM-E, KF-8010, X-22-161A, X- 22-5841, KF-9701, KF-857, KF-862, X-22-1660B-3 (all manufactured by Shin-Etsu Chemical Co., Ltd.) and the like.
Among these, PAM-E and KF-8010 are particularly preferable as the both-terminal amino group-modified polysiloxane.

  As said both terminal amino modified polysiloxane, it is preferable to contain 2 or more types of both terminal amino modified polysiloxane from which chain length differs rather than using it individually by 1 type. In this case, since the charge imparting ability of each amino group-modified polysiloxane having a different chain length differs depending on the toner, introduction at a desired ratio does not impair the mechanical strength of the electrophotographic electrophotographic carrier. The charge imparting ability to the toner can be freely adjusted in a wide range.

  As the both terminal amino-modified polysiloxanes, those having a chain length n calculated from the mass average molecular weight of 10 or less are particularly preferred. If the chain length n is greater than 10, it becomes difficult to form a uniform coating layer, the durability is greatly reduced, the coating layer wears and peels off, and a rapid charge imparting ability during use Deterioration may cause deterioration such as soiling.

<< (C) component >>
The said polyfunctional epoxy resin shows the polyfunctional epoxy compound which has 2-4 glycidyl groups in a molecule | numerator.
Specific examples of the polyfunctional epoxy compound include phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A type epoxy resin, ethylene glycol diglycidyl ether, glycerin triglycidyl ether, pentaerythritol tetraglycidyl ether, hydroquinone glycidyl ether, N, N-diglycidylaniline and the like can be mentioned. These polyfunctional epoxy compounds may be used individually by 1 type, and may use 2 or more types together.
Among these, the polyfunctional epoxy compound is particularly preferably a phenol novolac epoxy resin or a cresol novolac epoxy resin.

  When the binder resin precursor contains the components (A) to (C), the following effects can be obtained. That is, the adhesion to the core material is high with respect to the tough and low surface energy polymer formed by the reaction between the (A) diisocyanate compound and the (B) both-terminal amino-modified polysiloxane. The polyfunctional epoxy resin, which becomes a tough resin with high crosslink density, is intricately entangled and a film having chemical bonds partially formed on both sides is excellent in mechanical stress and effective in stain resistance. A single layer coating can be formed. Furthermore, by appropriately adjusting the ratio of amino-modified polysiloxanes having different chain lengths, a desired negative charge amount can be stably imparted to the toner over a long period of time without impairing the durability and spent resistance described above.

  Although the detailed mechanism of such an effect has not been clearly elucidated, the segment of low surface energy considered to be derived from both terminal amino-modified polysiloxanes in the single-layer coating layer has a very fine phase separation structure. This is considered to be due to the formation of a uniformly dispersed coating layer.

-Content-
The molar ratio (Mb / Ma) of the number of moles (Ma) of the (A) diisocyanate compound to the total number of moles (Mb) of the (B) both-terminal amino group-modified polysiloxane is preferably 0.5 to 3. When the molar ratio is less than 0.5 to more than 3, unreacted components are excessive and the amount of remaining low-molecular components increases, so that the mechanical strength deteriorates and the toner spent resistance deteriorates. The ability to impart a desired charge amount to the surface may be hindered, which is not preferable.

  Furthermore, as the mass ratio (mc / mT) of the content (mc) of the (C) polyfunctional epoxy resin to the total content (mT) of the (A) diisocyanate compound and (B) both-terminal amino group-modified polysiloxane, 0.005-0.1 is preferable, 0.005-0.075 is more preferable, and 0.01-0.05 is still more preferable. When mc / mT is less than 0.005, the strength of the film becomes insufficient, and when it exceeds 0.1, the amount of polyfunctional epoxy resin added becomes excessive, and it is difficult to form a uniform binder resin layer. The coating layer is not preferable because it may have a multi-layered structure or the toner spent resistance may be significantly deteriorated.

<< Other ingredients >>
The other component is not particularly limited and may be appropriately selected depending on the purpose.In order to make the electric resistance of the electrophotographic carrier appropriate, in the resin coating layer of the electrophotographic carrier, It is preferable to contain inorganic fine particles.
As the inorganic fine particles, known non-conductive materials and conductive materials can be used.

-Non-conductive material-
The non-conductive material can be contained in the coating layer, and the strength of the film is remarkably improved by selecting an appropriate content, particle size, etc., with respect to the thickness of the film formed. Can be made.
As such a non-conductive material, conventionally known materials can be used alone or in combination, and typically, silica, titanium oxide, alumina, colloidal silica having a diameter of 5 nm to 200 nm, and the like can be given.
Among these non-conductive materials, alumina fine particles are preferable in order to charge the toner negatively.

  The volume average particle diameter of the non-conductive material can be appropriately selected according to the thickness of the film, but is preferably 0.01 μm to 0.7 μm.

-Conductive material-
As the conductive material, for example, carbon black, conductive ZnO, metal powder such as Al; _SnO 2 doped with various SnO ₂ and various elements made by the _{method; TiB 2, ZnB 2, MoB} 2 , etc. Borides of silicon; silicon carbide; conductive polymers such as polyacetylene, polyparaphenylene, poly (para-phenylene sulfide), and polypyrrole. These may be used alone or in combination of two or more.
Among these, as the conductive material, a metal oxide whose surface is subjected to conductive treatment is preferable.

  The particle diameter of the metal oxide fine particles used for the thickness of the coating can be selected as appropriate. The thickness of the film here refers to the volume of the resin component that does not include the non-conductive material and the conductive material component among the components of the resin coating layer included in the electrophotographic carrier, and the magnetic material constituting the core material. It is the value divided by the surface area of the fine powder having.

  There is no restriction | limiting in particular as a volume average particle diameter of the said electroconductive material, Although it can select suitably according to the objective, 0.1 micrometer-1 micrometer are preferable. When the volume average particle diameter is less than 0.1 μm, the electrophotographic carrier may not have sufficient electric resistance adjusting ability. When the volume average particle diameter exceeds 1 μm, the conductive particles may be detached from stress. It is likely to occur, the resistance change with time becomes significant, and the image may be defective.

-Content-
Furthermore, the content of the conductive material and the non-conductive material is appropriately selected depending on the material constituting the film formed into a film, but is preferably 1% by mass to 60% by mass. When the content exceeds 60% by mass. Fine particles are likely to be detached from the film, which may cause a problem in durability.

<< Method for Forming Coating Layer >>
There is no restriction | limiting in particular as a formation method of the said coating layer, According to the objective, it can select suitably, For example, the apply | coating method etc. are mentioned.
The application method can be appropriately selected from conventionally known methods. For example, a method of applying a coating layer solution to the surface of the core material (core material particles) by means of a spray method or a dipping method, etc. Is mentioned.

  Furthermore, it is preferable to accelerate the condensation or cross-linking reaction of the coating layer resin by heating the electrophotographic carrier particles coated and formed in this way.

  This heat treatment may be continued in the coating apparatus after the coating layer is formed, or may be performed by another heating means such as a normal electric furnace or firing kiln after the coating layer is formed.

Further, the heat treatment temperature for the coating is not particularly limited and can be appropriately selected depending on the coating layer material to be used, but is preferably 120 ° C to 450 ° C, and in particular, the Curie temperature of the carrier core material for electrophotography. It is more preferable that the upper limit temperature is about the following temperature.
There is no restriction | limiting in particular as said heat processing time, Although it can select suitably according to the objective, 5 minutes-120 minutes are preferable.

<< Physical properties of electrophotographic carrier >>
The volume average particle diameter (Dw) of the electrophotographic carrier is preferably 20 μm to 65 μm, and more preferably 20 μm to 50 μm. When the volume average particle size is less than 20 μm, electrophotographic carrier adhesion may occur due to a decrease in uniformity of the core material. When the volume average particle size exceeds 65 μm, reproducibility of image details is poor. , A fine image may not be obtained.

The volume resistance of the electrophotographic carrier is preferably 10 (log Ω · cm) to 16 (log Ω · cm), more preferably 11 (log Ω · cm) to 16 (log Ω · cm). When the volume resistance is less than 10 (log Ω · cm), electrophotographic carrier adhesion may occur in the non-image area. When the volume resistance exceeds 16 (log Ω · cm), the image density at the edge portion during development is low. The so-called edge effect that is emphasized may become noticeable.
The volume resistance can be adjusted as necessary within the range of the volume resistance by adjusting the thickness of the coating layer and the content of the conductive fine particles to be contained.

(Electrophotographic developer)
The electrophotographic developer (two-component developer) of the present invention includes the electrophotographic carrier of the present invention and a toner. Thereby, electrophotographic carrier adhesion can be suppressed, and an electrophotographic developer that can cope with high image quality can be obtained.

  The mixing ratio of the toner and the electrophotographic carrier in the electrophotographic developer is preferably 2.0 parts by mass to 12.0 parts by mass of toner with respect to 100 parts by mass of the electrophotographic carrier. 2.5 mass parts-10 mass parts are more preferable.

  In the electrophotographic developer, the charge amount of the toner when the coverage of the electrophotographic carrier with the toner is 50% is preferably −50 μc / g to −10 μc / g, and −30 μc / g to -15 μc / g is more preferred. When the charge amount is less than −50 μc / g, background stain and toner scattering increase, and when it exceeds −10 μc / g, the electrophotographic carrier adheres easily.

  In the electrophotographic developer comprising the electrophotographic carrier of the present invention and a toner, the coverage of the electrophotographic carrier with the toner is preferably 10% to 90%, more preferably 20% to 80%. .

FIG. 1 is a schematic diagram for explaining a method for measuring the charge amount of a developer.
A certain amount of developer 3 is put into a conductor container 1 (cage) having metal meshes 2 (made of stainless steel) at both ends. The mesh of the metal mesh 2 is selected so that the toner 4 and the electrophotographic carrier have an intermediate particle size (mesh 20 μm), and the toner 4 is set to pass between the metal mesh 2. When a compressed nitrogen gas (1 kgf / cm ² ) is blown from the nozzle 5 for 60 seconds to cause the toner 4 to jump out of the conductor container 1, a carrier having a polarity opposite to the charge of the toner 4 remains in the conductor container 1. .

  The charge amount (Q) and the mass (M) of the protruding toner are measured, and the charge amount per unit mass is calculated as the charge amount (Q / M). The toner charge amount is expressed in μc / g. In addition, the said coverage is computed by the following formula | equation.

Coverage (%) = (Wt / Wc) × (ρc / ρt) × (Dc / Dt) × (1/4) × 100
In the above formula, Wt is the toner mass (g), Wc is the electrophotographic carrier mass (g), ρt is the toner true density (g / cm ³ ), and ρc is the electrophotographic carrier true density (g). g / cm ³ ), Dc represents the mass average particle diameter (μm) of the electrophotographic carrier, and Dt represents the mass average particle diameter (μm) of the toner.

<Toner>
The toner is not particularly limited and may be appropriately selected from those used as electrophotographic toners according to the purpose, and includes at least a binder resin and a colorant, and a release agent and a charge control agent. In addition, other components are included as necessary.

<< Binder resin >>
The binder resin is not particularly limited and may be appropriately selected from known ones according to the purpose. For example, styrene such as polystyrene, poly-p-styrene, polyvinyltoluene, or a homopolymer of a substituted product thereof. Styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-methacrylic acid copolymer Polymerization unit, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer Polymer, styrene-vinyl methyl ether copolymer, styrene-vinyl methyl ketone Copolymer, styrene-butadiene copolymer, styrene-isopropyl copolymer, styrene-copolymer such as styrene-maleic ester copolymer, polythyme methacrylate resin, polybutyl methacrylate resin, polyvinyl chloride resin , Polyvinyl acetate resin, polyethylene resin, polyester resin, polyurethane resin, epoxy resin, polyvinyl butyral resin, polyacrylic acid resin, rosin resin, modified rosin resin, terpene resin, phenol resin, aliphatic or aromatic hydrocarbon resin, aromatic Family petroleum resin. These may be used individually by 1 type and may use 2 or more types together.

<< Colorant >>
The colorant is not particularly limited and may be appropriately selected from known dyes and pigments according to the purpose. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Lead Red, Lead Red, Cadmium Red, Cad Muum Mercury Red, Antimon Zhu, Permanent Red 4R, PA Red, Faise Red, Parachlor Ortho Nitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Risor Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pogment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oh Lured, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), Indigo, Ultramarine Blue, Bitumen, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Oxidation Chrome, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Ash Examples include degreen lake, malachite green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, and litbon. These may be used individually by 1 type and may use 2 or more types together.

  The content of the colorant in the toner is preferably 1% by mass to 15% by mass, and more preferably 3% by mass to 10% by mass.

  The colorant may be used as a master batch combined with a resin. The resin is not particularly limited and may be appropriately selected from known ones according to the purpose. For example, styrene or a substituted polymer thereof, styrene copolymer, polymethyl methacrylate resin, polybutyl Methacrylate resin, polyvinyl chloride resin, polyvinyl acetate resin, polyethylene resin, polypropylene resin, polyester resin, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, fat Aromatic hydrocarbon resin, alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin and the like. These may be used individually by 1 type and may use 2 or more types together.

<< Releasing agent >>
There is no restriction | limiting in particular as said mold release agent, According to the objective, it can select suitably from well-known things, For example, waxes etc. are mentioned suitably.

  Examples of the waxes include carbonyl group-containing waxes, polyolefin waxes, long chain hydrocarbons, and the like. These may be used individually by 1 type and may use 2 or more types together. Among these, a carbonyl group-containing wax is preferable.

-Carbonyl group-containing wax-
Examples of the carbonyl group-containing wax include polyalkanoic acid esters, polyalkanol esters, polyalkanoic acid amides, polyalkylamides, dialkyl ketones, and the like. Examples of the polyalkanoic acid ester include carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18-octadecane. Examples thereof include diol distearate.

Examples of the polyalkanol ester include tristearyl trimellitic acid and distearyl maleate.
Examples of the polyalkanoic acid amide include dibehenyl amide.
Examples of the polyalkylamide include trimellitic acid tristearylamide.
Examples of the dialkyl ketone include distearyl ketone.
Of these carbonyl group-containing waxes, polyalkanoic acid esters are particularly preferred.

-Polyolefin wax-
Examples of the polyolefin wax include polyethylene wax and polypropylene wax.

-Long chain hydrocarbons-
Examples of the long chain hydrocarbon include paraffin wax and sazol wax.

-Melting point-
There is no restriction | limiting in particular as melting | fusing point of the said mold release agent, Although it can select suitably according to the objective, 40 to 160 degreeC is preferable, 50 to 120 degreeC is more preferable, and 60 to 90 degreeC is especially preferable. preferable. When the melting point is less than 40 ° C., the wax may adversely affect the heat-resistant storage stability, and when it exceeds 160 ° C., a cold offset may easily occur during fixing at a low temperature.

-Melt viscosity-
The melt viscosity of the release agent is preferably 5 cps to 1,000 cps, more preferably 10 cps to 100 cps, as measured at a temperature 20 ° C. higher than the melting point of the wax. If the melt viscosity is less than 5 cps, the releasability may be lowered, and if it exceeds 1,000 cps, the effect of improving hot offset resistance and low-temperature fixability may not be obtained.

-Content-
There is no restriction | limiting in particular as content in the said toner of the said mold release agent, Although it can select suitably according to the objective, 1 mass%-40 mass% are preferable, and 3 mass%-30 mass% are more preferable. . When the content exceeds 40% by mass, the fluidity of the toner may be deteriorated.

<< Charge Control Agent >>
The charge control agent is not particularly limited, and a positive or negative charge control agent can be appropriately selected and used according to the positive / negative of the charge charged on the photoreceptor.

-Negative charge control agent-
As the negative charge control agent, for example, a resin or compound having an electron donating functional group, an azo dye, a metal complex of an organic acid, or the like can be used.
Specifically, Bontron (product numbers: S-31, S-32, S-34, S-36, S-37, S-39, S-40, S-44, E-81, E-82, E -84, E-86, E-88, A, 1-A, 2-A, 3-A) (all manufactured by Orient Chemical Co., Ltd.), Kaya Charge (product numbers: N-1, N-2) Kaya Set Black (Part No .: T-2, 004) (all manufactured by Nippon Kayaku Co., Ltd.); Eisenspiron Black (T-37, T-77, T-95, TRH, TNS-2) (all Also manufactured by Hodogaya Chemical Co., Ltd.); FCA-1001-N, FCA-1001-NB, FCA-1001-NZ (all manufactured by Fujikura Chemical Co., Ltd.), and the like. These may be used individually by 1 type and may use 2 or more types together.

-Positive charge control agent-
Examples of the positive charge control agent include basic compounds such as nigrosine dyes; cationic compounds such as quaternary ammonium salts; and metal salts of higher fatty acids.
Specifically, Bontron (part numbers: N-01, N-02, N-03, N-04, N-05, N-07, N-09, N-10, N-11, N-13, P -51, P-52, AFP-B) (all manufactured by Orient Chemical Co., Ltd.); TP-302, TP-415, TP-4040 (all manufactured by Hodogaya Chemical Co., Ltd.); Copy Blue PR , Copy charge (part numbers: PX-VP-435, NX-VP-434) (both manufactured by Hoechst); FCA (part numbers: 201, 201-B-1, 201-B-2, 201-B-3) , 201-PB, 201-PZ, 301) (all manufactured by Fujikura Kasei Co., Ltd.); PLZ (product numbers: 1001, 2001, 6001, 7001) (all manufactured by Shikoku Kasei Kogyo Co., Ltd.), and the like. . These may be used individually by 1 type and may use 2 or more types together.

  The addition amount of the charge control agent is not particularly limited and can be appropriately selected according to the kind of the binder resin, the toner production method including the dispersion method, and the like, with respect to 100 parts by mass of the binder resin. 0.1 mass part-10 mass parts are preferable, and 0.2 mass part-5 mass parts are more preferable. When the added amount exceeds 10 parts by mass, the chargeability of the toner is too high, the effect of the charge control agent is reduced, the electrostatic attraction with the developing roller is increased, and the fluidity of the electrophotographic developer is lowered. If the amount is less than 0.1 part by mass, the charging start-up property and the charge amount may not be sufficient, and the toner image may be easily affected.

<< Other ingredients >>
There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, For example, inorganic fine particles, a fluid improvement agent, a cleaning property improvement agent, a magnetic material, metal soap, etc. are mentioned.

-Inorganic fine particles-
Examples of the inorganic fine particles include silica, titania, alumina, cerium oxide, strontium titanate, calcium carbonate, magnesium carbonate, calcium phosphate, etc., and silica hydrophobized with silicone oil, hexamethyldisilazane, or the like. It is more preferable to use fine particles or titanium oxide subjected to a specific surface treatment.

  Examples of the silica fine particles include, for example, Aerosil (product numbers: 130, 200 V, 200 CF, 300, 300 CF, 380, OX50, TT600, MOX80, MOX170, COK84, RX200, RY200, R972, R974, R976, R805, R811, R812, T805, R202, VT222, RX170, RXC, RA200, RA200H, RA200HS, RM50, RY200, REA200) (all manufactured by Nippon Aerosil Co., Ltd.), HDK (part numbers: H20, H2000, H3004, H2000 / 4, H2050EP, H2015EP) , H3050EP, KHD50), HVK2150 (all manufactured by Wacker Chemical Co., Ltd.), Cabozil (Part No .: L-90, LM-130, LM-150, M-5, PTG) MS-55, H-5, HS-5, EH-5, LM-150D, M-7D, MS-75D, TS-720, TS-610, TS-530) (all manufactured by Cabot) Can be used. These may be used alone or in combination of two or more.

  The addition amount of the inorganic fine particles is preferably 0.1 parts by mass to 5.0 parts by mass, and more preferably 0.8 parts by mass to 3.2 parts by mass with respect to 100 parts by mass of the toner base particles.

<< Manufacturing method >>
The toner production method is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a pulverization method, a monomer composition containing a specific crystalline polymer and a polymerizable monomer may be used. A polymerization method that directly polymerizes in an aqueous phase (suspension polymerization method, emulsion polymerization method), a composition containing a specific crystalline polymer and an isocyanate group-containing prepolymer directly in the aqueous phase with amines Examples thereof include a polyaddition reaction method using elongation / crosslinking, a polyaddition reaction method using an isocyanate group-containing prepolymer, a method of dissolving in a solvent, removing the solvent, and pulverizing, and a melt spraying method.

-Grinding method-
The pulverization method is, for example, a method of obtaining the toner base particles by melting or kneading the toner material, pulverizing, classifying or the like. In the case of the pulverization method, for the purpose of increasing the average circularity of the toner, the shape may be controlled by applying a mechanical impact force to the obtained toner base particles. In this case, the mechanical impact force can be applied to the toner base particles using a device such as a hybridizer or mechanofusion.

  The above toner materials are mixed, and the mixture is charged into a melt kneader and melt kneaded. As the melt kneader, for example, a uniaxial continuous kneader, a biaxial continuous kneader, or a batch kneader using a roll mill can be used. For example, KTK type twin screw extruder manufactured by Kobe Steel Co., Ltd., TEM type extruder manufactured by Toshiba Machine Co., Ltd., twin screw extruder manufactured by Casey Kay Co., Ltd., PCM type twin screw extruder manufactured by Ikegai Iron Works, Inc. A manufactured kneader or the like is preferably used. This melt-kneading is preferably performed under appropriate conditions so as not to cause the molecular chains of the binder resin to be broken. Specifically, the melt kneading temperature is performed with reference to the softening point of the binder resin. If the temperature is higher than the softening point, cutting is severe, and if the temperature is too low, dispersion may not proceed.

  In the pulverization, the kneaded product obtained by the kneading is pulverized. In this pulverization, it is preferable that the kneaded material is first coarsely pulverized and then finely pulverized. In this case, it is preferable to use a method of pulverizing by colliding with a collision plate in a jet stream, pulverizing particles by colliding with each other in a jet stream, or pulverizing in a narrow gap between a mechanically rotating rotor and a stator. It is done.

  In the classification, the pulverized product obtained by the pulverization is classified and adjusted to particles having a predetermined particle diameter. The classification can be performed, for example, by removing the fine particle portion by a cyclone, a decanter, centrifugation, or the like.

  After the pulverization and classification are completed, the pulverized product is classified into an air stream by centrifugal force or the like to produce a toner having a predetermined particle size.

-Suspension polymerization method-
The suspension polymerization method will be described later in an aqueous medium in which a colorant, a release agent, and the like are dispersed in an oil-soluble polymerization initiator, a polymerizable monomer, and a surfactant and other solid dispersants are contained. Emulsified and dispersed by an emulsification method. Thereafter, a polymerization reaction is performed to form particles, and then wet processing for attaching inorganic fine particles to the toner particle surfaces in the present invention may be performed. At that time, it is preferable to treat the toner particles from which excess surfactant and the like are removed by washing.

  Examples of the polymerizable monomer include acrylic acids, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid, maleic anhydride, and other acids, acrylamide, By using a part of acrylate or methacrylate having amino group such as methacrylamide, diacetone acrylamide or their methylol compounds, vinyl pyridine, vinyl pyrrolidone, vinyl imidazole, ethyleneimine, dimethylaminoethyl methacrylate, etc. Functional groups can be introduced.

  Further, by selecting a dispersant having an acid group or a basic group as the dispersant to be used, the dispersant can be adsorbed and left on the particle surface to introduce a functional group.

-Emulsion polymerization method-
As the emulsion polymerization method, a water-soluble polymerization initiator and a polymerizable monomer are emulsified in water using a surfactant, and a latex is synthesized by a usual emulsion polymerization method. Separately, a dispersion in which a colorant, a release agent and the like are dispersed in an aqueous medium is prepared, and after mixing, the toner is aggregated to a toner size and heat-fused to obtain a toner. Thereafter, wet processing of inorganic fine particles described later may be performed. A functional group can be introduced on the surface of the toner particles by using a latex similar to the monomer used in the suspension polymerization method.

  Among these, since the selectivity of the resin is high, the low-temperature fixability is high, the granulation property is excellent, and the particle size, particle size distribution, and shape can be easily controlled. And a polymer capable of reacting with the active hydrogen group-containing compound is dissolved or dispersed in an organic solvent to prepare a toner solution, and then the toner solution is emulsified or dispersed in an aqueous medium. A liquid is prepared, and the active hydrogen group-containing compound and a polymer capable of reacting with the active hydrogen group-containing compound are reacted in the aqueous medium to form an adhesive substrate in the form of particles, and the organic solvent What is obtained by removing is preferred.

  Examples of the toner material include an adhesive base obtained by reacting an active hydrogen group-containing compound, a polymer capable of reacting with the active hydrogen group-containing compound, a binder resin, a charge control agent, and a colorant. And, if necessary, other components such as resin fine particles and a release agent.

Further, in order to improve the fluidity, storage stability, developability, and transferability of the toner, inorganic fine particles such as hydrophobic silica fine powder may be further added and mixed with the toner base particles produced as described above. .
For mixing the additive, a general powder mixer is used, but it is preferable to equip a jacket or the like to adjust the internal temperature. In order to change the load history applied to the additive, the additive may be added midway or gradually. In this case, you may change the rotation speed, rolling speed, time, temperature, etc. of a mixer. Also, a strong load may be given first, then a relatively weak load, or vice versa. Examples of the mixing equipment that can be used include a V-type mixer, a rocking mixer, a Ladige mixer, a Nauter mixer, and a Henschel mixer. Next, the toner is obtained by passing through a sieve of 250 mesh or more to remove coarse particles and aggregated particles.

  The shape, size, etc. of the toner are not particularly limited and can be appropriately selected according to the purpose. The average circularity, volume average particle size, volume average particle size and number are as follows. It is preferable to have a ratio to the average particle size (volume average particle size / number average particle size).

  The average circularity is a value obtained by dividing the perimeter of an equivalent circle having the same projected shape as the toner shape by the perimeter of the actual particles, and is preferably 0.900 to 0.980, for example, 0.950 to 0 .975 is more preferred. Note that particles having an average circularity of less than 0.94 are preferably 15% or less.

  If the average circularity is less than 0.900, satisfactory transferability and a high-quality image free from dust may not be obtained. If the average circularity exceeds 0.980, image formation employing blade cleaning or the like is employed. In the system, defective cleaning occurs on the photoconductor and the transfer belt, and in the case of image formation with a high image area ratio such as a photographic image, an untransferred image is formed due to defective paper feeding, etc. The accumulated toner may become a transfer residual toner on the photoconductor, resulting in background smearing of the image, or it may contaminate the charging roller for charging the photoconductor in contact with the original charging ability. It may become impossible to demonstrate.

  The average circularity is measured using a flow type particle image analyzer (“FPIA-2100”, manufactured by Sysmex Corporation) and analyzed using analysis software (FPIA-2100 Data Processing Program for FPIA version 00-10). went.

  Specifically, 10% by weight surfactant (alkylbenzene sulfonate, Neogen SC-A, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) is added to a glass 100 mL beaker, and each toner 0 Add 1 g to 0.5 g, stir with microspatel, then add 80 mL of ion exchanged water. The obtained dispersion is subjected to a dispersion treatment for 3 minutes with an ultrasonic disperser (manufactured by Honda Electronics Co., Ltd.). Using the FPIA-2100, the dispersion is measured for toner shape and distribution until a density of 5,000 / μL to 15,000 / μL is obtained. In this measurement method, it is important that the concentration of the dispersion is 5,000 / μL to 15,000 / μL from the viewpoint of measurement reproducibility of the average circularity.

In order to obtain the dispersion concentration, it is necessary to change the conditions of the dispersion, that is, the amount of surfactant to be added and the amount of toner.
Similar to the measurement of the toner particle size described above, the required amount of the surfactant varies depending on the hydrophobicity of the toner, and if it is added in a large amount, noise due to bubbles is generated. If the amount is small, the toner cannot be sufficiently wetted. , Dispersion becomes insufficient. The amount of toner added varies depending on the particle size, and is small when the particle size is small and needs to be increased when the particle size is large. By adding 1 g to 0.5 g, the dispersion concentration can be adjusted to 5,000 / μL to 15,000 / μL.

  There is no restriction | limiting in particular as a volume average particle diameter of the said toner, Although it can select suitably according to the objective, 3 micrometers-10 micrometers are preferable, and 3 micrometers-8 micrometers are more preferable. When the volume average particle size is less than 3 μm, in the electrophotographic developer, the toner is fused to the surface of the electrophotographic carrier during a long period of stirring in the developing device, and the charging ability of the electrophotographic carrier is reduced. If it exceeds 10 μm, it becomes difficult to obtain a high-resolution and high-quality image, and when the balance of the toner in the electrophotographic developer is carried out, the fluctuation of the toner particle size may increase. is there.

The ratio of the volume average particle diameter to the number average particle diameter (volume average particle diameter / number average particle diameter) in the toner is preferably 1.00 to 1.25, more preferably 1.10 to 1.25. .
The volume average particle diameter and the ratio between the volume average particle diameter and the number average particle diameter (volume average particle diameter / number average particle diameter) are measured using a particle size measuring device (“Multisizer III” manufactured by Beckman Coulter, Inc.). Measurement can be performed with an aperture diameter of 100 μm, and analysis can be performed with analysis software (Beckman Coulter Multisizer 3 Version 3.51).

  Specifically, 0.5 mL of 10 mass% surfactant (alkylbenzene sulfonate Neogen SC-A, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) is added to a 100 mL glass beaker, and 0.5 g of each toner is added. Stir with microspatel, then add 80 mL of ion exchanged water. The obtained dispersion is subjected to a dispersion treatment for 10 minutes with an ultrasonic disperser (W-113MK-II, manufactured by Honda Electronics Co., Ltd.). The dispersion is measured using the Multisizer III and Isoton III (manufactured by Beckman Coulter, Inc.) as the measurement solution. In the measurement, the toner sample dispersion is dropped so that the concentration indicated by the apparatus is 8 ± 2%. In this measurement method, it is important that the concentration is 8 ± 2% from the viewpoint of measurement reproducibility of the particle size. Within this concentration range, no error occurs in the particle size.

  Although the charge amount of the toner varies depending on the actual use process, it cannot be determined unconditionally. However, in the combination with the electrophotographic carrier particles according to the configuration of the present invention, the saturation charge amount is 3 μC in absolute value. / G to 40 μC / g are preferable, and 5 μC / g to 30 μC / g are more preferable.

  The coloration of the toner is not particularly limited and can be appropriately selected according to the purpose, and can be at least one selected from black toner, cyan toner, magenta toner, and yellow toner. The toner can be obtained by appropriately selecting the type of the colorant, but is preferably a color toner.

(Container for electrophotographic developer)
The electrophotographic developer-containing container used in the present invention contains the electrophotographic developer of the present invention in a container.

  There is no restriction | limiting in particular as said container, It can select suitably from well-known things, For example, the thing etc. which have an electrophotographic developer container main body and a cap are mentioned suitably.

  The electrophotographic developer container body is not particularly limited in size, shape, structure, material, and the like, and can be appropriately selected according to the purpose. For example, the shape may be a cylindrical shape or the like Preferably, the inner peripheral surface is formed with spiral irregularities, and the toner as the contents can be transferred to the discharge port side by rotating, and part or all of the spiral part has a bellows function. And the like are particularly preferred.

  The material of the electrophotographic developer container main body is not particularly limited, and those having good dimensional accuracy are preferable. For example, a resin is preferably used. For example, polyester resin, polyethylene resin, polypropylene resin, polystyrene resin, Preferable examples include vinyl chloride resin, polyacrylic acid, polycarbonate resin, ABS resin, polyacetal resin, and the like.

  The electrophotographic developer-containing container of the present invention is easy to store and transport, has excellent handleability, and is detachably attached to the process cartridge and image forming apparatus of the present invention, which will be described later. It can be used suitably for replenishment.

(Process cartridge)
The process cartridge of the present invention develops an electrostatic latent image carrier carrying an electrostatic latent image and the electrostatic latent image carried on the electrostatic latent image carrier using an electrophotographic developer. And at least developing means for forming a visible image, and further having other means appropriately selected as necessary.

  As the developing means, an electrophotographic developer container for accommodating the electrophotographic developer of the present invention, and an electrophotographic developer accommodated in the electrophotographic developer container and carrying and transporting the electrophotographic developer. At least a developer carrying member for electrophotography, and a layer thickness regulating member for regulating the thickness of the toner layer to be carried.

  The process cartridge can be detachably mounted on various electrophotographic image forming apparatuses, and is preferably detachably mounted on an image forming apparatus used in the present invention described later.

  Here, for example, as shown in FIG. 2, the process cartridge includes an electrostatic latent image carrier 101, and includes a charging unit 102, a developing unit 104, a transfer unit 108, and a cleaning unit 107. And other means. In FIG. 2, reference numeral 103 denotes exposure by exposure means, and 105 denotes a recording medium.

  Next, the image forming process using the process cartridge shown in FIG. 2 will be described. The electrostatic latent image carrier 101 is rotated by the charging means 102 while rotating in the direction of the arrow, and the exposure 103 by the exposure means (not shown). An electrostatic latent image corresponding to the exposure image is formed on the surface. The electrostatic latent image is developed by the developing unit 104, and the obtained visible image is transferred to the recording medium 105 by the transfer unit 108 and printed out. Next, the surface of the latent electrostatic image bearing member after the image transfer is cleaned by the cleaning unit 107, further neutralized by a neutralizing unit (not shown), and the above operation is repeated again.

(Image forming method and image forming apparatus)
The image forming method of the present invention includes at least an electrostatic latent image forming step, a developing step, a transfer step, and a fixing step, and other steps appropriately selected as necessary, for example, a static elimination step, a cleaning step. , Recycling process, control process, etc.
The image forming apparatus used in the present invention includes at least an electrostatic latent image carrier, an electrostatic latent image forming unit, a developing unit, a transfer unit, and a fixing unit, and further appropriately selected as necessary. The other means, for example, a static elimination means, a cleaning means, a recycling means, a control means, etc. are provided.

<Electrostatic latent image forming step and electrostatic latent image forming means>
The electrostatic latent image forming step is a step of forming an electrostatic latent image on the electrostatic latent image carrier.
The latent electrostatic image bearing member (sometimes referred to as “electrophotographic photosensitive member”, “photosensitive member”, “image bearing member”) is not particularly limited in terms of material, shape, structure, size, and the like. Although it can be appropriately selected from known ones, the shape is preferably a drum shape, and examples of the material include inorganic photoreceptors such as amorphous silicon and selenium, and organic materials such as polysilane and phthalopolymethine. And a photoconductor (OPC). Among these, amorphous silicon is preferable in terms of long life.

  The formation of the electrostatic latent image can be performed, for example, by uniformly charging the surface of the electrostatic latent image carrier and then performing imagewise exposure, and is performed by the electrostatic latent image forming unit. be able to.

  The electrostatic latent image forming means includes, for example, at least a charger that uniformly charges the surface of the electrostatic latent image carrier and an exposure device that exposes the surface of the electrostatic latent image carrier imagewise. Prepare.

  The charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using the charger.

  The charger is not particularly limited and may be appropriately selected depending on the purpose. For example, a known contact charging device including a conductive or semiconductive roll, brush, film, rubber blade, etc. And non-contact chargers using corona discharge such as corotrons and corotrons.

Further, the charger is preferably one that is arranged in contact or non-contact with the electrostatic latent image carrier and charges the surface of the electrostatic latent image carrier by applying DC and AC voltages in a superimposed manner.
The charger is a charging roller that is disposed in close proximity to the electrostatic latent image carrier via a gap tape. The electrostatic latent image carrier is applied by applying a direct current and an alternating voltage to the charging roller. Those that charge the body surface are preferred.

  The exposure can be performed, for example, by exposing the surface of the latent electrostatic image bearing member imagewise using the exposure device.

  The exposure device is not particularly limited as long as it can expose the surface of the electrostatic latent image carrier charged by the charger so as to form an image to be formed, and is appropriately selected according to the purpose. For example, various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system can be used.

  In the present invention, a back light system in which imagewise exposure is performed from the back side of the electrostatic latent image carrier may be employed.

<Development process and development means>
The developing step is a step of developing the electrostatic latent image using the electrophotographic developer of the present invention to form a visible image.

  The visible image can be formed, for example, by developing the electrostatic latent image using the electrophotographic developer of the present invention, and can be performed by the developing unit.

  The developing means is not particularly limited as long as it can be developed using, for example, the electrophotographic developer of the present invention, and can be appropriately selected from known ones. For example, the electron of the present invention Preferably, the electrophotographic developer according to the present invention includes a photographic developer and at least a developing device capable of bringing the electrophotographic developer into contact or non-contact with the electrostatic latent image. A developing device provided with a container containing an agent is more preferable.

  The developing unit may be a dry developing type, a wet developing type, a single color developing unit, or a multi-color developing unit. For example, a preferable example includes a stirrer that frictionally stirs and charges the electrophotographic developer and a rotatable magnet roller.

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

<Transfer process and transfer means>
The transfer step is a step of transferring the visible image onto a recording medium. After the primary transfer of the visible image onto the intermediate transfer member using an intermediate transfer member, the visible image is transferred onto the recording medium. A primary transfer step of forming a composite transfer image by transferring a visible image onto an intermediate transfer body using two or more colors, preferably full color toner as the toner, and a composite transfer image; A mode including a secondary transfer step of transferring the transfer image onto the recording medium is more preferable.

  The transfer can be performed, for example, by charging the latent electrostatic image bearing member (photoconductor) of the visible image using a transfer charger, and can be performed by the transfer unit. The transfer means includes a primary transfer means for transferring a visible image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer means for transferring the composite transfer image onto a recording medium. Embodiments are preferred.

  The intermediate transfer member is not particularly limited and can be appropriately selected from known transfer members according to the purpose. For example, a transfer belt and the like are preferable.

The transfer means (the primary transfer means and the secondary transfer means) is a transfer for peeling and charging the visible image formed on the electrostatic latent image carrier (photoconductor) to the recording medium side. It is preferable to have at least a vessel. There may be one transfer means or two or more transfer means.
Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.

  The recording medium is not particularly limited and can be appropriately selected from known recording media (recording paper).

<Fixing process and fixing means>
The fixing step is a step of fixing the visible image transferred to the recording medium using a fixing unit, and may be performed each time the toner of each color is transferred to the recording medium, or for the toner of each color. You may perform this simultaneously in the state which laminated | stacked this.

  The fixing unit (fixing device) is not particularly limited and may be appropriately selected depending on the intended purpose. However, a known heating and pressing unit is preferable. Examples of the heating and pressing means include a combination of a heating roller and a pressure roller, a combination of a heating roller, a pressure roller, and an endless belt.

  The fixing device includes a heating body including a heating element, a film in contact with the heating body, and a pressure member in pressure contact with the heating body through the film, and the film and the pressure member It is preferably a unit that heats and fixes a recording medium on which an unfixed image is formed. The heating in the heating and pressing means is usually preferably 80 ° C to 200 ° C.

  In the present invention, for example, a known optical fixing device may be used together with or in place of the fixing step and the fixing unit depending on the purpose.

<< Static elimination process and static elimination means >>
The neutralization step is a step of performing neutralization by applying a neutralization bias to the electrostatic latent image carrier, and can be suitably performed by a neutralization unit.

  The neutralization means is not particularly limited, and may be appropriately selected from known neutralizers as long as it can apply a neutralization bias to the electrostatic latent image carrier. Preferably mentioned.

<< Cleaning process and cleaning means >>
The cleaning step is a step of removing the toner remaining on the electrostatic latent image carrier and can be suitably performed by a cleaning unit.

  The cleaning means is not particularly limited as long as it can remove the electrophotographic toner remaining on the electrostatic latent image carrier, and can be appropriately selected from known cleaners. Suitable examples include brush cleaners, electrostatic brush cleaners, magnetic roller cleaners, blade cleaners, brush cleaners, and web cleaners.

<< Recycling process and recycling means >>
The recycling step is a step of recycling the toner removed by the cleaning step to the developing unit, and can be suitably performed by the recycling unit.

  There is no restriction | limiting in particular as said recycling means, A well-known conveyance means etc. are mentioned.

<< Control process and control means >>
The control step is a step of controlling each of the steps, and can be suitably performed by a control unit.

  The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.

  One mode of carrying out the image forming method of the present invention by the image forming apparatus will be described with reference to FIG. An image forming apparatus 100 shown in FIG. 3 includes a photosensitive drum 10 (hereinafter referred to as “photosensitive member 10”) as the electrostatic latent image carrier, a charging roller 20 as the charging unit, and an exposure as the exposure unit. The apparatus 30 includes a developing device 40 as the developing means, an intermediate transfer member 50, a cleaning device 60 as the cleaning means having a cleaning blade, and a static elimination lamp 70 as the static elimination means.

  The intermediate transfer member 50 is an endless belt, and is designed to be movable in the direction of the arrow in the figure by three rollers 51 that are arranged on the inner side and stretch the belt. Part of the three rollers 51 also functions as a transfer bias roller that can apply a predetermined transfer bias (primary transfer bias) to the intermediate transfer member 50. An intermediate transfer member cleaning blade 90 is disposed in the vicinity of the intermediate transfer member 50, and a transfer bias for transferring a visible image (toner image) to the recording medium 95 (secondary transfer) is applied. Possible transfer rollers 80 as the transfer means are arranged to face each other. Around the intermediate transfer member 50, a corona charger 58 for applying a charge to the visible image on the intermediate transfer member 50 is connected to the electrostatic latent image carrier 10 in the rotation direction of the intermediate transfer member 50. The contact portion between the intermediate transfer member 50 and the contact portion between the intermediate transfer member 50 and the recording medium 95 is disposed.

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

  In the image forming apparatus 100 shown in FIG. 3, for example, the charging roller 20 uniformly charges the photosensitive drum 10. The exposure device 30 performs imagewise exposure on the photosensitive drum 10 to form an electrostatic latent image. The electrostatic latent image formed on the photosensitive drum 10 is developed by supplying toner from the developing device 40 to form a visible image (toner image). The visible image (toner image) is transferred (primary transfer) onto the intermediate transfer member 50 by the voltage applied from the roller 51, and further transferred (secondary transfer) onto the transfer paper 95. As a result, a transfer image is formed on the transfer paper 95. The residual toner on the photoconductor 10 is removed by the cleaning device 60, and the charge on the photoconductor 10 is temporarily removed by the charge eliminating lamp 70.

  Another mode for carrying out the image forming method of the present invention by the image forming apparatus will be described with reference to FIG. The image forming apparatus 100 shown in FIG. 4 does not include the developing belt 41 in the image forming apparatus 100 shown in FIG. 4, and a black developing unit 45K, a yellow developing unit 45Y, a magenta developing unit 45M, The cyan developing unit 45C has the same configuration as that of the image forming apparatus 100 shown in FIG. In FIG. 4, the same components as those in FIG. 3 are denoted by the same reference numerals.

  Another mode for carrying out the image forming method of the present invention by the image forming apparatus of the present invention will be described with reference to FIG. The tandem image forming apparatus shown in FIG. 5 is a tandem type color image forming apparatus. The tandem image forming apparatus includes a copying apparatus main body 150, a paper feed table 200, a scanner 300, and an automatic document feeder (ADF) 400.

  The copying apparatus main body 150 is provided with an endless belt-like intermediate transfer member 50 at the center. The intermediate transfer member 50 is stretched around the support rollers 14, 15, and 16 and can rotate clockwise in FIG. 5. An intermediate transfer member cleaning device 17 for removing residual toner on the intermediate transfer member 50 is disposed in the vicinity of the support roller 15. The intermediate transfer member 50 stretched between the support roller 14 and the support roller 15 is a tandem type in which four image forming units 18 of yellow, cyan, magenta, and black are arranged to face each other along the conveyance direction. A developing device 120 is disposed. An exposure device 21 is disposed in the vicinity of the tandem developing device 120. A secondary transfer device 22 is disposed on the side of the intermediate transfer member 50 opposite to the side on which the tandem developing device 120 is disposed. In the secondary transfer device 22, a secondary transfer belt 24 that is an endless belt is stretched around a pair of rollers 23, and a recording medium (transfer paper) conveyed on the secondary transfer belt 24 and an intermediate transfer member 50. Can contact each other. A fixing device 25 is disposed in the vicinity of the secondary transfer device 22. The fixing device 25 includes a fixing belt 26 that is an endless belt, and a pressure roller 27 that is pressed against the fixing belt 26.

  In the tandem image forming apparatus, a sheet reversing device 28 for reversing the transfer paper for image formation on both sides of the transfer paper is disposed in the vicinity of the secondary transfer device 22 and the fixing device 25. .

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

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

  Each image information of black, yellow, magenta, and cyan is stored in each image forming unit 18 (black image forming unit, yellow image forming unit, magenta image forming unit, and cyan image) in the tandem developing device 120. Each of the image forming units forms black, yellow, magenta, and cyan toner images. That is, each image forming means 18 (black image forming means, yellow image forming means, magenta image forming means, and cyan image forming means) in the tandem type developing device 120 is a static image as shown in FIG. An electrostatic latent image carrier 10 (black electrostatic latent image carrier 10K, yellow electrostatic latent image carrier 10Y, magenta electrostatic latent image carrier 10M, and cyan electrostatic latent image carrier 10C); The electrostatic latent image bearing member 10 is uniformly charged, and the electrostatic latent image bearing member is exposed (L in FIG. 6) for each color image corresponding to each color image information. An exposure device that forms an electrostatic latent image corresponding to each color image on the electrostatic latent image carrier, and each color toner (black toner, yellow toner, magenta toner, and cyan toner) Develop with A developing device 61 for forming a toner image with each color toner, a transfer charger 62 for transferring the toner image onto the intermediate transfer member 50, a cleaning device 63, and a static eliminator 64 are provided. Each single color image (black image, yellow image, magenta image, and cyan image) can be formed based on the color image information. The black image, the yellow image, the magenta image, and the cyan image formed in this way are respectively transferred to the black electrostatic latent image carrier 10K on the intermediate transfer member 50 that is rotationally moved by the support rollers 14, 15, and 16. Black image formed on top, yellow image formed on electrostatic latent image carrier 10Y for yellow, magenta image formed on electrostatic latent image carrier 10M for magenta, and electrostatic latent image carrier for cyan The cyan image formed on 10C is sequentially transferred (primary transfer). Then, the black image, the yellow image, the magenta image, and the cyan image are superimposed on the intermediate transfer member 50 to form a composite color image (color transfer image).

  On the other hand, in the paper feed table 200, one of the paper feed rollers 142 is selectively rotated to feed out a sheet (recording paper) from one of the paper feed cassettes 144 provided in multiple stages in the paper bank 143. Each sheet is separated and sent to the paper feed path 146, transported by the transport roller 147, guided to the paper feed path 148 in the copying machine main body 150, and abutted against the registration roller 49 and stopped. Alternatively, the sheet feed roller 142 is rotated to feed out sheets (recording paper) on the manual feed tray 54, separated one by one by the separation roller 52, put into the manual feed path 53, and abutted against the registration roller 49 and stopped. . The registration roller 49 is generally used while being grounded, but may be used in a state where a bias is applied to remove paper dust from the sheet. Then, the registration roller 49 is rotated in synchronization with the synthesized color image (color transfer image) synthesized on the intermediate transfer member 50, and a sheet (recording paper) is interposed between the intermediate transfer member 50 and the secondary transfer device 22. The secondary color transfer device 22 transfers the composite color image (color transfer image) onto the sheet (recording paper), thereby transferring the color image onto the sheet (recording paper). Is formed. The residual toner on the intermediate transfer member 50 after image transfer is cleaned by the intermediate transfer member cleaning device 17.

  The sheet (recording paper) on which the color image has been transferred is conveyed by the secondary transfer device 22 and sent to the fixing device 25, where the combined color image (color) is generated by heat and pressure. (Transfer image) is fixed on the sheet (recording paper). Thereafter, the sheet (recording paper) is switched by the switching claw 55 and discharged by the discharge roller 56 and stacked on the discharge tray 57, or switched by the switching claw 55 and reversed by the sheet reversing device 28 and transferred again. After being guided to the position and recording an image on the back surface, the image is discharged by the discharge roller 56 and stacked on the discharge tray 57.

  EXAMPLES The present invention will be specifically described below with reference to examples of the present invention, but the present invention is not limited to these examples.

Example 1
<Preparation of Electrophotographic Carrier 1>
9 parts by mass of diisocyanate (component (A), B-830: manufactured by Mitsui Chemicals Polyurethane Co., Ltd.), 2.14 parts by mass of both end amino group-modified polysiloxanes having a chain length of 0.2 (component (B), PAM-E) : Shin-Etsu Chemical Co., Ltd.) and 0.56 parts by mass of diethylene glycol diglycidyl ether (component (C), EX-850: manufactured by Nagase Chemtech Co., Ltd.), thermal initiator 0.0056 parts by mass (in diethylene glycol diglycidyl ether) 1% by mass) (Sun aid SI-80L: manufactured by Sanshin Chemical Industry Co., Ltd.) was mixed, dissolved in a THF solution so as to be 20% by mass, and stirred at room temperature for 12 hours. Subsequently, it was dispersed with a homomixer for 10 minutes to prepare [Coating Layer Liquid 1].
The mass ratio (mc / mT) of the content (mc) of component (C) to the total content (mT) of component (A) and component (B) is 0.05.

  Next, using a ferrite powder (saturation magnetic moment 65 emu / g at 1 k gauss) as a core material, a rolling fluid type coating apparatus is used so that the [coating layer liquid 1] has a thickness of 1.0 μm on the core material surface. After being used, it was dried at 60 ° C. for 10 minutes to obtain an electrophotographic carrier precursor. The obtained electrophotographic carrier precursor was baked in an electric furnace at 180 ° C. for 60 minutes, and after cooling, the ferrite powder bulk was crushed using a sieve having an opening of 90 μm, and [electrophotographic carrier] 1] was produced.

The mass average particle diameter (Dw) of the obtained [Electrophotographic carrier 1] was measured using “Microtrac particle size analyzer SRA (manufactured by Nikkiso Co., Ltd.) and in a range of 0.7 μm to 125 μm.
Moreover, the volume resistivity (LogR) was measured with a high resist meter (manufactured by Yokogawa Hewlett-Packard Co., Ltd., High Resistance Meter). The results are shown in Table 6.

<Preparation of Toner 1>
-Synthesis of organic fine particle emulsion-
In a reaction vessel in which a stir bar and a thermometer are set, 683 parts by mass of water, 11 parts by mass of an ethylene oxide adduct sulfate sulfate salt (Eleminol RS-30, manufactured by Sanyo Chemical Industries, Ltd.), 166 parts by mass of methacrylic acid Part, 110 parts by mass of butyl acrylate, and 1 part by mass of ammonium persulfate were stirred at 3,800 rpm for 30 minutes to obtain a white emulsion. This was heated to raise the system temperature to 75 ° C. and reacted for 4 hours. Further, 30 parts by mass of a 1% by mass ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 6 hours to form a vinyl-based resin (methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt copolymer). An aqueous dispersion [fine particle dispersion 1] was obtained.

  The obtained [Fine Particle Dispersion 1] was measured with a particle size distribution analyzer (LA-920, manufactured by Horiba, Ltd.), and the volume average particle size was 110 nm. Further, a portion of the obtained [fine particle dispersion 1] was dried to isolate the resin component. The glass transition temperature (Tg) of the resin was 58 ° C., and the mass average molecular weight was 130,000.

-Preparation of aqueous phase-
990 parts by weight of water, 83 parts by weight of [Fine Particle Dispersion 1], 37 parts by weight of an aqueous solution of 48.3% by weight of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7, manufactured by Sanyo Chemical Industries, Ltd.), and 90 parts by weight of ethyl acetate Were mixed and stirred to obtain a milky white liquid. This is designated as [Aqueous Phase 1].

-Synthesis of low molecular weight polyester-
229 parts by mass of bisphenol A ethylene oxide 2-mole adduct, 529 parts by mass of bisphenol A propylene oxide 3-mole adduct, 208 parts by mass of terephthalic acid, adipic acid 46 parts by mass and 2 parts by mass of dibutyltin oxide were added, reacted at 230 ° C. under normal pressure for 7 hours, further reacted at a reduced pressure of 10 mmH to 15 mmHg for 5 hours, and then trimellitic anhydride 44 mass in the reaction vessel. A low molecular weight polyester 1 was obtained by reacting at 180 ° C. for 3 hours under normal pressure. [Low molecular weight polyester 1] had a number average molecular weight of 2,300, a weight average molecular weight of 6,700, a glass transition temperature (Tg) of 43 ° C., and an acid value of 25 mgKOH / g.

-Synthesis of intermediate polyester and prepolymer-
In a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, 682 parts by mass of bisphenol A ethylene oxide 2 mol adduct, 81 parts by mass of bisphenol A propylene oxide 2 mol adduct, 283 parts by mass of terephthalic acid, 22 parts by mass of merit acid and 2 parts by mass of dibutyltin oxide were added, reacted at 230 ° C. for 7 hours under normal pressure, and further reacted for 5 hours at a reduced pressure of 10 mmHg to 15 mmHg to obtain [Intermediate Polyester 1]. [Intermediate Polyester 1] had a number average molecular weight of 2,200, a weight average molecular weight of 9,700, a glass transition temperature (Tg) of 54 ° C., an acid value of 0.5 mgKOH / g, and a hydroxyl value of 52 mgKOH / g.

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

-Synthesis of ketimine compounds-
In a reaction vessel equipped with a stirrer and a thermometer, 170 parts by mass of isophoronediamine and 75 parts by mass of methyl ethyl ketone were charged and reacted at 50 ° C. for 4 hours and half to obtain [ketimine compound 1]. The amine value of the obtained [ketimine compound 1] was 417.

-Production of master batch (MB)-
1,200 parts by weight of water, 540 parts by weight of carbon black (Printex35, manufactured by Dexa) [DBP oil absorption = 42 mL / 100 mg, pH = 9.5], and 1,200 parts by weight of the low molecular weight polyester resin were added. The mixture was mixed with a mixer (manufactured by Mitsui Mining Co., Ltd.), and the mixture was kneaded at 110 ° C. for 1 hour using two rolls, cooled by rolling, and pulverized with a pulverizer to obtain [Masterbatch 1].

-Preparation of oil phase-
378 parts by mass of [Low molecular polyester 1], 100 parts by mass of carnauba wax, and 947 parts by mass of ethyl acetate were charged in a container in which a stir bar and a thermometer were set, and the temperature was raised to 80 ° C. with stirring. This was maintained for 5 hours and then cooled to 30 ° C. in 1 hour. Next, 500 parts by mass of [Masterbatch 1] and 500 parts by mass of ethyl acetate were charged into the container and mixed for 1 hour to obtain [Raw material solution 1].

  [Raw material solution 1] 1,324 parts by mass are transferred into a container, and using a bead mill (Ultra Visco Mill, manufactured by IMEX), liquid feeding speed is 1 kg / hour, disk peripheral speed is 6 m / second, 0.5 mm zirconia beads. The carbon black and the wax were dispersed under the condition of 80% by volume and 3 passes. Next, 1,324 parts by mass of a 65% by weight ethyl acetate solution of [low molecular weight polyester 1] was added, and the mixture was subjected to two passes with a bead mill under the above conditions to obtain [Pigment / Wax Dispersion 1]. The solid content concentration of [Pigment / Wax Dispersion 1] (130 ° C., 30 minutes) was 50 mass%.

-Emulsification and solvent removal-
[Pigment / Wax Dispersion 1] 749 parts by mass, [Prepolymer 1] 115 parts by mass, and [Ketimine Compound 1] 2.9 parts by mass are placed in a container, and TK homomixer (manufactured by Tokushu Kika Co., Ltd.) After mixing at 5,000 rpm for 2 minutes, 1,200 parts of [Aqueous phase 1] was added to the container and mixed with a TK homomixer at 13,000 rpm for 25 minutes to obtain [Emulsion slurry 1].

  [Emulsion slurry 1] was put into a container equipped with a stirrer and a thermometer, and after removing the solvent at 30 ° C. for 8 hours, aging was carried out at 40 ° C. for 24 hours to obtain [Dispersion slurry 1].

-Washing and drying-
[Dispersion Slurry 1] 100 parts by mass were filtered under reduced pressure to obtain a filter cake (a), washed and filtered as follows, and dried to obtain [Mother toner particles 1].
(1) 100 parts by mass of ion-exchanged water was added to the filter cake (a), mixed with a TK homomixer (10 minutes at a rotation speed of 12,000 rpm), and then filtered to obtain a filter cake (b).
(2) Add 100 parts by mass of a 10% by mass aqueous sodium hydroxide solution to the filter cake (b), mix with a TK homomixer (30 minutes at 12,000 rpm), filter under reduced pressure, and filter cake (c). Obtained.
(3) 100 parts by mass of 10% by mass hydrochloric acid was added to the filter cake (c), mixed with a TK homomixer (10 minutes at 12,000 rpm), and then filtered to obtain a filter cake (d).
Add 300 parts by mass of ion-exchanged water to the filter cake (d) of (4), mix with a TK homomixer (10 minutes at 12,000 rpm), and then filter twice to obtain [Filter cake 1]. It was.

  [Filter cake 1] was dried at 45 ° C. for 48 hours in a circulating dryer. Thereafter, the mixture was sieved with a mesh of 75 μm to prepare [Toner Base Particle 1] having a volume average particle size of 6.1 μm, a number average particle size of 5.4 μm, and an average circularity of 0.972.

-Preparation of [Toner 1]-
Finally, 0.7 parts by weight of hydrophobic silica and 0.3 parts by weight of hydrophobic titanium oxide are mixed with 100 parts by weight of the obtained [toner base particle 1] using a Henschel mixer to prepare [Toner 1]. did.

<Preparation of electrophotographic developer (two-component developer) 1>
The produced [Toner 1] and [Electrophotographic carrier 1] were adjusted so that the coverage of the electrophotographic carrier with the toner was 50%, and stirred with a tumbler mixer (manufactured by Shinmaru Enterprises). Electrophotographic developer 1] was prepared.

<Evaluation of [Electrophotographic Developer 1]>
Using the obtained [Electrophotographic developer 1], the toner charge amount (μC / g) when the coverage was 50% was measured as follows. Further, peeling and scraping of the coating layer, toner spent property, image density, toner scattering property, and background stain were evaluated. The respective evaluation results are shown in Table 6.

-Measurement of toner charge amount-
[Electrophotographic developer 1] 0.5 g was put in a conductor container (cage) having metal meshes (made of stainless steel) at both ends. The mesh opening of the metal mesh was set to 20 μm. Compressed nitrogen gas (1 kgf / cm ² ) is blown from the nozzle for 60 seconds, causing [Toner 1] to jump out of the conductor container, leaving a carrier having a polarity opposite to that of [Toner 1] in the conductor container. It was. The charge amount (Q) and the mass (M) of the protruded [toner 1] are measured, and the charge amount per unit mass is defined as the charge amount (Q / M), and the coverage of [toner 1] is 50%. The toner charge amount (μC / g) at this time was calculated.

-Evaluation of peeling and scraping of coating layer-
Each of the produced electrophotographic developers was subjected to a running evaluation of 200,000 sheets using a tandem color image forming apparatus (imagio Neo450, manufactured by Ricoh Co., Ltd.), and the resistance reduction amount of the electrophotographic carrier after the running was completed. The ratio (resistance reduction after 200,000 sheets run / resistance reduction at the initial stage of run) was evaluated according to the following criteria.
〔Evaluation criteria〕
◎: 1/10 or more ○: 1/100 or more and less than 1/10 △: 1/1000 or more and less than 1/100 ×: less than 1/1000

  Here, the amount of resistance reduction refers to the electrophotographic carrier before running between the resistance measurement parallel electrodes: electrodes having a gap of 2 mm, DC200V is applied, and the resistance value after 30 seconds is the high resist meter (Yokogawa Hewlett-Packard Co., Ltd.) An electrophotographic carrier obtained by removing the toner in the electrophotographic developer after running from the value (R1) obtained by converting the value measured by the company High Resistance Meter into volume resistivity using the blow-off device. It means the amount obtained by subtracting the value (R2) measured by the same method as the resistance measuring method, and the target value is 2.0 [Log (Ω · cm)] or less. Moreover, since the cause of resistance reduction is detachment | desorption from the core material of the coating layer of the carrier for electrophotography, the amount of resistance reduction can be suppressed by reducing scraping. Normally, the resistance before running in the initial run is the largest.

-Evaluation of toner spent property-
Using the produced [Electrophotographic developer 1] using a tandem color image forming apparatus (image Neo Neo 450, manufactured by Ricoh Co., Ltd.), a chart of 20% image area is adjusted to an image density of 1.4 ± 0.2. The amount of change (μc / g) in the charge amount (μc / g) of the electrophotographic developer after output of 200,000 sheets is controlled while the toner density is controlled (the decrease amount of charge amount after 200,000 sheet run / charge amount at the initial stage of run). In comparison with the initial value before output, the evaluation was made according to the following criteria. The charge amount was measured by a blow-off method.
〔Evaluation criteria〕
◎: Less than 15% ○: 15% or more and less than 30% △: 30% or more and less than 50% ×: 50% or more

  As the toner spends on the electrophotographic carrier, the composition of the outermost surface of the electrophotographic carrier changes, and the charge amount decreases. It is determined that the smaller the change in the charge amount before and after the run, the less the toner spent on the electrophotographic carrier.

-Evaluation of image density-
[Electrophotographic developer 1] is applied to a copy paper (TYPE6000 <70W>, manufactured by Ricoh Co., Ltd.) using a tandem color image forming apparatus (image Neo 450, manufactured by Ricoh Co., Ltd.). A solid image having an adhesion amount of 1.00 ± 0.05 mg / cm ² was formed. The solid image was repeatedly formed on 200,000 copy sheets.

The image density of the solid image obtained at the initial stage and after the 200,000 sheet endurance test was visually observed, and the image after the 200,000 sheet endurance test was evaluated based on the following criteria. Note that the higher the image density obtained, the higher the density image can be formed.
〔Evaluation criteria〕
◎: No change in image density and high image quality was obtained ○: Image density was slightly reduced, but high image quality was obtained △: Image density was lowered and image quality was lowered ×: Image density was significantly reduced , Image quality is greatly reduced

-Evaluation of toner scattering property-
In-machine toner contamination when 200,000 sheets of an image area ratio of 5% are continuously output using [Electrophotographic Developer 1] by a tandem type color image forming apparatus (Imagio Neo 450, manufactured by Ricoh Co., Ltd.). The degree of was visually evaluated in four stages according to the following criteria.
〔Evaluation criteria〕
A: There is no toner contamination in the image forming apparatus and it is in a good state. ○: There is no toner contamination in the image forming apparatus and it is in a good state. Δ: There is toner contamination in the image forming apparatus, but it is actually used. Possible level ×: Toner contamination in the image forming apparatus is severe and is not practically usable.

-Evaluation of dirt-
Using [Electrophotographic Developer 1], an image background portion when 200,000 sheets of an image area ratio of 5% are continuously output by a tandem color image forming apparatus (image Neo 450, manufactured by Ricoh Co., Ltd.) The degree of soiling was visually evaluated according to the following criteria.
〔Evaluation criteria〕
○: No background stain on the image background △: Some background stain on the image background ×: Background stain on the image background

-Comprehensive evaluation-
The above evaluation results were combined and evaluated according to the following criteria.
〔Evaluation criteria〕
A: Three or more in the evaluation of toner charge amount, coating layer peeling / scraping, toner spent property, image density, toner scattering property, and scumming ○: toner charging amount, coating layer peeling / scraping, toner Of the evaluations of spent property, image density, toner scattering property, and background stain, the number of 未 満 is less than 3 △: toner charge amount, coating layer peeling / scraping, toner spent property, image density, toner scattering property, and background stain Among the evaluations, the number of ◎ is 0 ×: Among the evaluations of toner charge amount, coating layer peeling / scraping, toner spent property, image density, toner scattering property, and background contamination, the number of × is 3 or more. Table 6 shows.

(Example 2)
<Preparation of Electrophotographic Carrier 2>
9 parts by mass of diisocyanate (component (A), B-830: made by Mitsui Chemicals Polyurethane), 2.14 parts by mass of both-end amine-modified polysiloxane having a chain length of 0.2 (component (B), PAM-E: Shin-Etsu Chemical) Manufactured by Kogyo Co., Ltd.), 0.56 parts by mass of 1,6-bis (2,3-epoxypropoxy) naphthalene (component (C), EPICLON HP4032D: manufactured by DIC), 0.0056 parts by mass of thermal initiator (1,6-bis (1% by mass with respect to (2,3-epoxypropoxy) naphthalene) (Sun-Aid SI-80L: manufactured by Sanshin Chemical Industry Co., Ltd.) was mixed, dissolved in THF solution to 20% by mass, and stirred at room temperature for 12 hours. Next, 5.6 parts by mass of alumina fine particles (Sumira Condam AA-04: manufactured by Sumitomo Chemical Co., Ltd.) were added and dispersed with a homomixer for 10 minutes to prepare [Coating Layer Liquid 2], which was used instead of [Coating Layer Liquid 1]. [Electrophotographic carrier 2] was prepared in the same manner as in Example 1 except that.
The mass ratio (mc / mT) of the content (mc) of component (C) to the total content (mT) of component (A) and component (B) is 0.05.

  Table 6 shows the mass average particle diameter (Dw) and volume resistivity (Log R) of the obtained [Electrophotographic carrier 2].

<Preparation of Electrophotographic Developer 2>
[Electrophotographic developer] in the same manner as in Example 1, except that [Electrophotographic carrier 1] was changed to [Electrophotographic carrier 2] in the production of [Electrophotographic developer 1] in Example 1. 2] was produced.

<Evaluation of Electrophotographic Developer 2>
The evaluation of [Electrophotographic developer 2] was carried out in the same manner as the evaluation of [Electrophotographic developer 1] in Example 1, and the results are shown in Table 6.

(Example 3)
<Preparation of Electrophotographic Carrier 3>
9 parts by mass of diisocyanate (component (A), B-830: made by Mitsui Chemicals Polyurethane), 2.14 parts by mass of both-end amine-modified polysiloxane having a chain length of 0.2 (component (B), PAM-E: Shin-Etsu Chemical) Manufactured by Kogyo Co., Ltd.), 0.56 parts by mass of cresol type novolak (component (C), EP4050G: manufactured by Asahi Organic Materials Co., Ltd.), 0.0056 parts by mass of thermal initiator (1% by mass with respect to cresol type novolak) (Sun Aid SI -80L: Sanshin Chemical Co., Ltd.), dissolved in a THF solution to 20% by mass, stirred at room temperature for 12 hours, and then dispersed with a homomixer for 10 minutes to prepare [Coating layer solution 3]. [Electrophotographic carrier 3] was prepared in the same manner as in Example 1 except that it was used instead of [Coating layer solution 1].
The mass ratio (mc / mT) of the content (mc) of component (C) to the total content (mT) of component (A) and component (B) is 0.05.

  Table 6 shows the mass average particle diameter (Dw) and volume resistivity (Log R) of the obtained [Electrophotographic carrier 3].

<Preparation of developer 3 for electrophotography>
[Electrophotographic developer] in the same manner as in Example 1, except that [Electrophotographic carrier 1] was changed to [Electrophotographic carrier 3] in the production of [Electrophotographic developer 1] in Example 1. 3] was produced.

<Evaluation of Electrophotographic Developer 3>
The evaluation of [Electrophotographic developer 3] was carried out in the same manner as in the evaluation of [Electrophotographic developer 1] in Example 1, and the results are shown in Table 6.

(Example 4)
<Preparation of Electrophotographic Carrier 4>
9 parts by mass of diisocyanate (component (A), B-830: made by Mitsui Chemicals Polyurethane), 2.14 parts by mass of both-end amine-modified polysiloxane having a chain length of 0.2 (component (B), PAM-E: Shin-Etsu Chemical) Manufactured by Kogyo Co., Ltd.), 0.56 parts by mass of cresol type novolak (component (C), EP4080G: manufactured by Asahi Organic Materials Co., Ltd.), 0.0056 parts by mass of thermal initiator (1% by mass with respect to cresol type novolak) (Sun Aid SI -80L: Sanshin Chemical Co., Ltd.) is mixed, dissolved in a THF solution so as to be 20% by mass and stirred at room temperature for 12 hours, and then 5.6 parts by mass of alumina fine particles (Sumilacon Dam AA-04: manufactured by Sumitomo Chemical Co., Ltd.). ) And dispersed for 10 minutes with a homomixer to prepare [Coating layer solution 4], and [Electrophotographic carrier 4] in the same manner as in Example 1 except that it was used instead of [Coating layer solution 1]. It was produced.
The mass ratio (mc / mT) of the content (mc) of component (C) to the total content (mT) of component (A) and component (B) is 0.05.

  Table 6 shows the mass average particle diameter (Dw) and volume resistivity (LogR) of the obtained [Electrophotographic carrier 4].

<Preparation of Electrophotographic Developer 4>
[Electrophotographic developer] in the same manner as in Example 1, except that [Electrophotographic carrier 1] was changed to [Electrophotographic carrier 4] in the production of [Electrophotographic developer 1] in Example 1. 4] was produced.

<Evaluation of Electrophotographic Developer 4>
The evaluation of [Electrophotographic developer 4] was carried out in the same manner as in the evaluation of [Electrophotographic developer 1] in Example 1, and the results are shown in Table 6.

(Example 5)
<Preparation of Electrophotographic Carrier 5>
9 parts by mass of diisocyanate (component (A), B-830: made by Mitsui Chemicals Polyurethane), 2.14 parts by mass of both-end amine-modified polysiloxane having a chain length of 0.2 (component (B), PAM-E: Shin-Etsu Chemical) Manufactured by Kogyo Co., Ltd.), 0.01 part by mass of cresol type novolak (component (C), EP4080G: manufactured by Asahi Organic Materials Co., Ltd.), 0.0001 part by mass of thermal initiator (1% by mass with respect to cresol type novolak) (Sun Aid SI -80L: Sanshin Chemical Co., Ltd.) is mixed, dissolved in a THF solution so as to be 20% by mass and stirred at room temperature for 12 hours, and then 5.6 parts by mass of alumina fine particles (Sumilacon Dam AA-04: manufactured by Sumitomo Chemical Co., Ltd.). ) And dispersed with a homomixer for 10 minutes to prepare [Coating layer solution 5], and [Electrophotographic carrier 5] in the same manner as in Example 1 except that it was used instead of [Coating layer solution 1]. It was produced.
In addition, mass ratio (mc / mT) with respect to the total content (mT) of (A) component and (B) component of content (mc) of (C) component is 0.001.

  Table 6 shows the mass average particle diameter (Dw) and volume resistivity (Log R) of the obtained [Electrophotographic Carrier 5].

<Preparation of Electrophotographic Developer 5>
[Electrophotographic developer] in the same manner as in Example 1 except that [Electrophotographic carrier 1] was changed to [Electrophotographic carrier 5] in the production of [Electrophotographic developer 1] in Example 1. 5] was produced.

<Evaluation of Electrophotographic Developer 5>
The evaluation of [Electrophotographic developer 5] was carried out in the same manner as the evaluation of [Electrophotographic developer 1] in Example 1, and the results are shown in Table 6.

(Example 6)
<Preparation of Electrophotographic Carrier 6>
9 parts by mass of diisocyanate (component (A), B-830: made by Mitsui Chemicals Polyurethane), 2.14 parts by mass of both-end amine-modified polysiloxane having a chain length of 0.2 (component (B), PAM-E: Shin-Etsu Chemical) Manufactured by Kogyo Co., Ltd.), 0.11 parts by mass of cresol type novolak (component (C), EP4080G: manufactured by Asahi Organic Materials Co., Ltd.), 0.0011 parts by mass of thermal initiator (1% by mass with respect to cresol type novolak) (Sun Aid SI -80L: Sanshin Chemical Co., Ltd.) is mixed, dissolved in a THF solution so as to be 20% by mass and stirred at room temperature for 12 hours, and then 5.6 parts by mass of alumina fine particles (Sumilacon Dam AA-04: manufactured by Sumitomo Chemical Co., Ltd.). ) And dispersed for 10 minutes with a homomixer to prepare [Coating layer solution 6], and [Electrophotographic carrier 6] in the same manner as in Example 1 except that it was used instead of [Coating layer solution 1]. It was produced.
The mass ratio (mc / mT) of the content (mc) of component (C) to the total content (mT) of component (A) and component (B) is 0.01.

<Preparation of Electrophotographic Developer 6>
[Electrophotographic developer] in the same manner as in Example 1 except that [Electrophotographic carrier 1] was changed to [Electrophotographic carrier 6] in the production of [Electrophotographic developer 1] in Example 1. 6] was produced.

<Evaluation of Electrophotographic Developer 6>
The evaluation of [Electrophotographic developer 6] was carried out in the same manner as the evaluation of [Electrophotographic developer 1] in Example 1, and the results are shown in Table 6.

(Example 7)
<Preparation of Electrophotographic Carrier 7>
9 parts by mass of diisocyanate (component (A), B-830: made by Mitsui Chemicals Polyurethane), 2.14 parts by mass of both-end amine-modified polysiloxane having a chain length of 0.2 (component (B), PAM-E: Shin-Etsu Chemical) Manufactured by Kogyo Co., Ltd.), 0.28 parts by mass of cresol type novolak (component (C), EP4080G: manufactured by Asahi Organic Materials Co., Ltd.), 0.0028 parts by mass of thermal initiator (1% by mass with respect to cresol type novolak) (Sun Aid SI -80L: Sanshin Chemical Co., Ltd.) was mixed, dissolved in a THF solution to 20% by mass and stirred at 60 ° C for 4 hours, and then 5.6 parts by mass of alumina fine particles (Sumilacon Dam AA-04: Sumitomo Chemical Industries). [Coating layer solution 7] was prepared by dispersing for 10 minutes with a homomixer, and was used in the same manner as in Example 1 except that it was used instead of [Coating layer solution 1]. It was produced.
In addition, mass ratio (mc / mT) with respect to the total content (mT) of (A) component and (B) component of content (mc) of (C) component is 0.025.

<Preparation of Electrophotographic Developer 7>
[Electrophotographic developer] in the same manner as in Example 1 except that [Electrophotographic carrier 1] was changed to [Electrophotographic carrier 7] in the production of [Electrophotographic developer 1] in Example 1. 7] was produced.

<Evaluation of Electrophotographic Developer 7>
The evaluation of [Electrophotographic developer 7] was carried out in the same manner as the evaluation of [Electrophotographic developer 1] in Example 1, and the results are shown in Table 6.

(Example 8)
<Preparation of Electrophotographic Carrier 8>
Diisocyanate 14 parts by mass (component (A), B-830: manufactured by Mitsui Chemicals Polyurethane Co., Ltd.) 3.34 parts by mass of both-end amine-modified polysiloxane having a chain length of 0.2 (component (B), PAM-E: Shin-Etsu) Chemical Industry), cresol type novolak 0.87 parts by mass (component (C), EP4050G: manufactured by Asahi Organic Materials Co., Ltd.), thermal initiator 0.0087 parts by mass (1% by mass with respect to cresol type novolak) ( Sun Aid SI-80L (manufactured by Sanshin Chemical Industry Co., Ltd.) was mixed and dissolved in a THF solution so as to be 20% by mass and stirred at room temperature for 12 hours to obtain a solution 8A.

  In another container, diisocyanate 11 parts by mass (component (A), B-830: manufactured by Mitsui Chemicals Polyurethanes Co., Ltd.) and chain end 7.9, both ends amine-modified polysiloxane 8.37 parts by mass (component (B), KF-8010: manufactured by Shin-Etsu Chemical Co., Ltd.), 0.97 parts by mass of cresol type novolak (EP4050G: manufactured by Asahi Organic Materials Co., Ltd.), 0.0097 parts by mass of thermal initiator (1% by mass with respect to cresol type novolak) ) (Sun-Aid SI-80L: manufactured by Sanshin Chemical Industry Co., Ltd.) was dissolved in a THF solution so as to be 20% by mass and stirred at room temperature for 12 hours, followed by stirring at 50 ° C. for 4 hours to obtain Solution 8B.

The solution 8A and the solution 8B thus obtained were mixed so as to have a mass ratio of 75:25, and 5.6 parts by mass of alumina fine particles (Sumira Condam AA-04: manufactured by Sumitomo Chemical Co., Ltd.) were added, and the mixture was mixed with a homomixer for 10 minutes. [Coating layer solution 8] was prepared by dispersing, and [Electrophotographic carrier 8] was prepared in the same manner as in Example 1 except that it was used instead of [Coating layer solution 1].
The mass ratio (mc / mT) of the content (mc) of component (C) to the total content (mT) of component (A) and component (B) is 0.05.

  Table 6 shows the mass average particle diameter (Dw) and volume resistivity (Log R) of the obtained [Electrophotographic carrier 8].

<Preparation of Electrophotographic Developer 8>
[Electrophotographic developer] in the same manner as in Example 1, except that [Electrophotographic carrier 1] was changed to [Electrophotographic carrier 8] in the production of [Electrophotographic developer 1] in Example 1. 8] was produced.

<Evaluation of Electrophotographic Developer 8>
The evaluation of [Electrophotographic developer 8] was carried out in the same manner as the evaluation of [Electrophotographic developer 1] in Example 1, and the results are shown in Table 6.

Example 9
<Preparation of Electrophotographic Carrier 9>
[Coating layer solution 9] was prepared in the same manner as in Example 8, except that the mixing ratio (mass ratio) of Solution 8A and Solution 8B in Example 8 was changed from 75:25 to 50:50. A carrier 9 was produced in the same manner as in Example 8 except that this [Coating Layer Liquid 9] was used instead of [Coating Layer Liquid 8], and [Coating Layer Liquid 9] was used instead of [Coating Layer Liquid 8]. [Electrophotographic carrier 9] was produced in the same manner as in Example 8 except that was used.

  Table 6 shows the mass average particle diameter (Dw) and volume resistivity (Log R) of the obtained [Electrophotographic carrier 9].

<Preparation of electrophotographic developer 9>
[Electrophotographic developer] in the same manner as in Example 1, except that [Electrophotographic carrier 1] was changed to [Electrophotographic carrier 9] in the production of [Electrophotographic developer 1] in Example 1. 9] was produced.

<Evaluation of Electrophotographic Developer 9>
The evaluation of [Electrophotographic developer 9] was carried out in the same manner as the evaluation of [Electrophotographic developer 1] in Example 1, and the results are shown in Table 6.

(Example 10)
<Preparation of Electrophotographic Carrier 10>
[Coating layer solution 10] was prepared in the same manner as in Example 8, except that the mixing ratio (mass ratio) of the solution 8A and the solution 8B in Example 8 was changed from 75:25 to 25:75. A carrier 9 was produced in the same manner as in Example 8 except that this [Coating layer solution 10] was used instead of [Coating layer solution 8], and [Coating layer solution 10] instead of [Coating layer solution 8]. [Electrophotographic carrier 10] was produced in the same manner as in Example 2 except that was used.

  Table 6 shows the mass average particle diameter (Dw) and volume resistivity (Log R) of the obtained [Electrophotographic carrier 10].

<Preparation of Electrophotographic Developer 10>
[Electrophotographic developer] in the same manner as in Example 1, except that [Electrophotographic carrier 1] was changed to [Electrophotographic carrier 10] in the production of [Electrophotographic developer 1] in Example 1. 10].

<Evaluation of Electrophotographic Developer 10>
The evaluation of [Electrophotographic developer 10] was carried out in the same manner as in the evaluation of [Electrophotographic developer 1] in Example 1, and the results are shown in Table 6.

(Example 11)
<Preparation of Electrophotographic Carrier 11>
9 parts by mass of diisocyanate (component (A), B-830: made by Mitsui Chemicals Polyurethane), 2.14 parts by mass of both-end amine-modified polysiloxane having a chain length of 0.2 (component (B), PAM-E: Shin-Etsu Chemical) Manufactured by Kogyo Co., Ltd.), 0.56 parts by mass of cresol type novolac glycidyl ether (component (C), YDCN-700-2: manufactured by Tohto Kasei Co., Ltd.), thermal initiator 0.0056 parts by mass (based on cresol type novolac glycidyl ether) (1% by mass) (Sun Aid SI-80L: Sanshin Chemical Co., Ltd.) was mixed and dissolved in a THF solution to 20% by mass and stirred at room temperature for 12 hours, and further stirred at 50 ° C. for 2 hours. Next, [Coating layer solution 11] was prepared by dispersing for 10 minutes with a homomixer, and [Electrophotographic carrier 11] was produced in the same manner as in Example 1 except that it was used instead of [Coating layer solution 1]. .
The mass ratio (mc / mT) of the content (mc) of component (C) to the total content (mT) of component (A) and component (B) is 0.05.

  Table 6 shows the mass average particle diameter (Dw) and volume resistivity (Log R) of the obtained [Electrophotographic carrier 11].

<Preparation of developer 11 for electrophotography>
[Electrophotographic developer] in the same manner as in Example 1, except that [Electrophotographic carrier 1] was changed to [Electrophotographic carrier 11] in the production of [Electrophotographic developer 1] in Example 1. 11] was produced.

<Evaluation of Electrophotographic Developer 11>
The evaluation of [Electrophotographic developer 11] was carried out in the same manner as the evaluation of [Electrophotographic developer 1] in Example 1, and the results are shown in Table 6.

(Example 12)
<Preparation of Electrophotographic Carrier 12>
Diisocyanate 6 parts by mass (component (A), B-830: made by Mitsui Chemicals Polyurethane), 4.56 parts by mass of both ends amine-modified polysiloxane having a chain length of 7.9 (component (B), KF8010: manufactured by Shin-Etsu Chemical Co., Ltd.) ), Cresol type novolak glycidyl ether 0.53 parts by mass (component (C), YDCN-700-2: manufactured by Tohto Kasei), thermal initiator 0.0053 parts by mass (1% by mass with respect to cresol type novolac glycidyl ether) (Sun aid SI-80L: manufactured by Sanshin Chemical Industry Co., Ltd.) was mixed and dissolved in a THF solution so as to be 20% by mass and stirred at room temperature for 12 hours, and then stirred at 50 ° C. for 2 hours. Subsequently, [Coating layer solution 12] was prepared by dispersing with a homomixer for 10 minutes, and [Electrophotographic carrier 12] was produced in the same manner as in Example 1 except that it was used instead of [Coating layer solution 1]. .
The mass ratio (mc / mT) of the content (mc) of component (C) to the total content (mT) of component (A) and component (B) is 0.05.

  Table 6 shows the mass average particle diameter (Dw) and volume resistivity (Log R) of the obtained [electrophotographic carrier 12].

<Preparation of Electrophotographic Developer 12>
[Electrophotographic developer] in the same manner as in Example 1 except that [Electrophotographic carrier 1] was changed to [Electrophotographic carrier 12] in the production of [Electrophotographic developer 1] in Example 1. 12] was produced.

<Evaluation of Electrophotographic Developer 12>
The evaluation of [Electrophotographic developer 12] was performed in the same manner as in the evaluation of [Electrophotographic developer 1] in Example 1, and the results are shown in Table 6.

(Example 13)
<Preparation of Electrophotographic Carrier 13>
9 parts by mass of diisocyanate (component (A), B-830: made by Mitsui Chemicals Polyurethane), 2.14 parts by mass of both-end amine-modified polysiloxane having a chain length of 0.2 (component (B), PAM-E: Shin-Etsu Chemical) Manufactured by Kogyo Co., Ltd.), 0.56 parts by mass of cresol type novolak glycidyl ether (component (C), YDCN-700-2: manufactured by Tohto Kasei Co., Ltd.), 0.0056 parts by mass of thermal initiator (cresol type novolak glycidyl ether) 1% by mass) (Sun aid SI-80L: manufactured by Sanshin Chemical Industry Co., Ltd.), dissolved in THF solution to 20% by mass and stirred at room temperature for 12 hours, and further at 50 ° C. for 2 hours. Stir to obtain solution 13A.

  In another container, 6 parts by mass of diisocyanate (component (A), B-830: manufactured by Mitsui Chemicals Polyurethanes Co., Ltd.), 4.56 parts by mass of both-end amine-modified polysiloxane having a chain length of 7.9 (component (B) , KF8010: manufactured by Shin-Etsu Chemical Co., Ltd.), cresol type novolac glycidyl ether 0.53 part by mass (component (C), YDCN-700-2: manufactured by Toto Kasei Co., Ltd.), thermal initiator 0.0053 part by mass (cresol) 1% by mass with respect to the type novolac glycidyl ether) (Sun-Aid SI-80L: manufactured by Sanshin Chemical Industry Co., Ltd.), dissolved in THF solution to 20% by mass and stirred at room temperature for 12 hours, and further The mixture was stirred at 50 ° C. for 2 hours to obtain a solution 13B.

The solution 13A and the solution 13B thus obtained were mixed at a mass ratio of 75:25, and 5.6 parts by mass of alumina fine particles (Sumira Condam AA-04: manufactured by Sumitomo Chemical Co., Ltd.) were added, and the mixture was mixed with a homomixer. [Coating layer solution 13] was prepared by dispersing for 10 minutes, and [Electrophotographic carrier 13] was produced in the same manner as in Example 1 except that it was used instead of [Coating layer solution 1].
The mass ratio (mc / mT) of the content (mc) of component (C) to the total content (mT) of component (A) and component (B) is 0.05.

  Table 6 shows the mass average particle diameter (Dw) and volume resistivity (Log R) of the obtained [Electrophotographic carrier 13].

<Preparation of Electrophotographic Developer 13>
[Electrophotographic developer] in the same manner as in Example 1 except that [Electrophotographic carrier 1] was changed to [Electrophotographic carrier 13] in the production of [Electrophotographic developer 1] in Example 1. 13].

<Evaluation of Electrophotographic Developer 13>
The evaluation of [Electrophotographic developer 13] was performed in the same manner as in the evaluation of [Electrophotographic developer 1] in Example 1, and the results are shown in Table 6.

(Example 14)
<Preparation of Electrophotographic Carrier 14>
[Coating layer solution 14] was prepared in the same manner as in Example 13 except that the mixing ratio (mass ratio) of the solution 13A and the solution 13B in Example 13 was changed from 75:25 to 50:50. A carrier 14 was prepared in the same manner as in Example 13 except that this [Coating layer solution 14] was used instead of [Coating layer solution 13], and [Coating layer solution 14] was used instead of [Coating layer solution 13]. [Electrophotographic carrier 14] was produced in the same manner as in Example 13 except that was used.

  Table 6 shows the mass average particle diameter (Dw) and volume resistivity (Log R) of the obtained [Electrophotographic carrier 14].

<Preparation of Electrophotographic Developer 14>
[Electrophotographic developer] in the same manner as in Example 1 except that [Electrophotographic carrier 1] was changed to [Electrophotographic carrier 14] in the production of [Electrophotographic developer 1] in Example 1. 14].

<Evaluation of Electrophotographic Developer 14>
The evaluation of [Electrophotographic developer 14] was carried out in the same manner as in the evaluation of [Electrophotographic developer 1] in Example 1, and the results are shown in Table 6.

(Example 15)
<Preparation of Electrophotographic Carrier 15>
[Coating layer solution 15] was prepared in the same manner as in Example 13 except that the mixing ratio (mass ratio) of the solution 13A and the solution 13B in Example 13 was changed from 75:25 to 25:75. A carrier 15 was prepared in the same manner as in Example 13 except that this [Coating layer solution 15] was used instead of [Coating layer solution 13], and [Coating layer solution 15] was used instead of [Coating layer solution 13]. [Electrophotographic carrier 15] was produced in the same manner as in Example 13 except that was used.

  Table 6 shows the mass average particle diameter (Dw) and volume resistivity (Log R) of the obtained [Electrophotographic carrier 15].

<Preparation of Electrophotographic Developer 15>
[Electrophotographic developer] in the same manner as in Example 1, except that [Electrophotographic carrier 1] was changed to [Electrophotographic carrier 15] in the production of [Electrophotographic developer 1] in Example 1. 15].

<Evaluation of Electrophotographic Developer 15>
The evaluation of [Electrophotographic developer 15] was carried out in the same manner as in the evaluation of [Electrophotographic developer 1] in Example 1, and the results are shown in Table 6.

(Comparative Example 1)
<Preparation of Electrophotographic Carrier 16>
The following materials are diluted with toluene so that the solid content concentration becomes 20%, and then dispersed with a homomixer for 10 minutes to prepare [Coating layer solution 16]. Instead of [Coating layer solution 1], [Coating layer solution 1] An electrophotographic carrier 16 was produced in the same manner as in Example 1 except that the layer solution 16] was used.
-Silicone resin solution (SR2405, manufactured by Toray Dow Corning Co., Ltd.)
Solid content 50% by mass) 14 parts by mass Aminosilane coupling agent (manufactured by Toray Dow Corning Co., Ltd.,
SH6020, solid content 100% by mass) 0.14 parts by mass Carbon black (MA100R: manufactured by Mitsubishi Chemical Industries) 1.0 part by mass

  Table 6 shows the mass average particle diameter (Dw) and volume resistivity (LogR) of the obtained [Electrophotographic carrier 16].

<Preparation of Electrophotographic Developer 16>
[Electrophotographic developer] in the same manner as in Example 1 except that [Electrophotographic carrier 1] was changed to [Electrophotographic carrier 16] in the production of [Electrophotographic developer 1] in Example 1. 16] was produced.

<Evaluation of Electrophotographic Developer 16>
The evaluation of [Electrophotographic developer 16] was carried out in the same manner as in the evaluation of [Electrophotographic developer 1] in Example 1, and the results are shown in Table 6.

(Comparative Example 2)
<Preparation of Electrophotographic Carrier 17>
The following materials were diluted with toluene so that the solid content concentration was 20%, and then dispersed with a homomixer for 10 minutes to prepare [Coating layer solution 17]. [Coating layer solution 1] was replaced with [Coating layer solution 1]. An electrophotographic carrier 17 was produced in the same manner as in Example 1 except that the layer solution 17] was used.
Acrylic resin (methyl methacrylate 60% by mass, butyl acrylate 34% by mass,
2 mass parts guanamine solution (Mitsui Cytec Co., Ltd., Mycoat 106,
(Solid content 77% by mass) 1.3 parts by mass / silicone resin solution (manufactured by Dow Corning Toray, SR2405,
Solid content 50% by mass) 8 parts by mass Aminosilane coupling agent (manufactured by Toray Dow Corning Co., Ltd.,
SH6020, solid content 100% by mass) 0.12 parts by mass Alumina fine particles (Sumitomo Chemical Co., Ltd. Sumirakondam, AA-04,
Particle size 0.4μm) 3 parts by mass

  Table 6 shows the mass average particle diameter (Dw) and volume resistivity (Log R) of the obtained [Electrophotographic carrier 17].

<Preparation of Electrophotographic Developer 17>
[Electrophotographic developer] in the same manner as in Example 1, except that [Electrophotographic carrier 1] was changed to [Electrophotographic carrier 17] in the production of [Electrophotographic developer 1] in Example 1. 17].

<Evaluation of Electrophotographic Developer 17>
The evaluation of [Electrophotographic developer 17] was carried out in the same manner as the evaluation of [Electrophotographic developer 1] in Example 1, and the results are shown in Table 6.

(Comparative Example 3)
<Preparation of Electrophotographic Carrier 18>
4 parts by mass of carbon black (VXC-72: manufactured by Cabot) was added to 40 parts by mass of trifunctional isocyanate (D110N: manufactured by Takeda Pharmaceutical Co., Ltd.) and 20 parts by mass of diisocyanate (Sumijoule T: manufactured by Sumitomo Bayer Urethane). Ethyl acetate was added and mixed by heating at 60 ° C. Next, 20 parts by mass of both-end amine-modified polysiloxane (X-22-161A: manufactured by Shin-Etsu Chemical Co., Ltd.) and 5 parts by mass of diethylenetriamine are mixed and dissolved in an ethyl acetate solution so that the total solid content concentration becomes 20% by mass. Then, the mixture was dispersed with a homomixer for 10 minutes to prepare [Coating layer solution 18], and the same procedure as in Example 1 was performed except that [Coating layer solution 18] was used instead of [Coating layer solution 1]. Thus, an electrophotographic carrier 18 was produced.

  Table 6 shows the mass average particle diameter (Dw) and volume resistivity (Log R) of the obtained [Electrophotographic carrier 18].

<Preparation of Electrophotographic Developer 18>
[Electrophotographic developer] in the same manner as in Example 1, except that [Electrophotographic carrier 1] was changed to [Electrophotographic carrier 18] in the production of [Electrophotographic developer 1] in Example 1. 18].

<Evaluation of Electrophotographic Developer 18>
The evaluation of [Electrophotographic developer 18] was carried out in the same manner as in the evaluation of [Electrophotographic developer 1] in Example 1, and the results are shown in Table 6.

(Comparative Example 4)
<Preparation of Electrophotographic Carrier 19>
The following materials are diluted with THF so that the solid content concentration becomes 20%, and then dispersed with a homomixer for 10 minutes to prepare [Coating layer solution 19]. Instead of [Coating layer solution 1], [Coating layer solution 1] An electrophotographic carrier 19 was produced in the same manner as in Example 1 except that the layer solution 19] was used.
-Cresol type novolac resin (EP4080G) 10 parts by mass-Aminosilane coupling agent (manufactured by Dow Corning Toray,
SH6020, solid content 100% by mass) 0.16 parts by mass / alumina fine particles (Sumitomo Chemical Co., Ltd., Sumirakondam, AA-04,
Particle size 0.4μm) 3 parts by mass

Table 6 shows the mass average particle diameter (Dw) and volume resistivity (Log R) of the obtained [Electrophotographic Carrier 19].
<Preparation of Electrophotographic Developer 19>
[Electrophotographic developer] in the same manner as in Example 1, except that [Electrophotographic carrier 1] was changed to [Electrophotographic carrier 19] in the production of [Electrophotographic developer 1] in Example 1. 19].

<Evaluation of Electrophotographic Developer 19>
The evaluation of [Electrophotographic developer 19] was carried out in the same manner as the evaluation of [Electrophotographic developer 1] in Example 1, and the results are shown in Table 6.

  The components of the coating layer liquids of Examples 1 to 15 and Comparative Examples 1 to 4 are summarized in Tables 1 to 5.

  The electrophotographic carriers of Examples 1 to 15 obtained very good overall results with respect to peeling and scraping of the coating layer, toner spent property, image density, toner scattering property and background stain. On the other hand, Comparative Example 1 to Comparative Example 4 are generally inferior in peeling and scraping of the coating layer, toner spent property, image density, toner scattering property, and background stain as compared with Example 1 to Example 15. all right.

The electrophotographic carrier of the present invention and the electrophotographic developer using the electrophotographic carrier can be used in a desired range without causing problems of image quality deterioration, toner scattering and background contamination due to toner spent and surface wear. Since the charge amount can be adjusted, it is suitably used for developing a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method or the like.
Since the image forming apparatus, the image forming method, and the process cartridge of the present invention use the electrophotographic developer of the present invention and can form an extremely high quality image, for example, a laser printer, direct digital plate making, etc. It can be widely used in full-color copiers, full-color laser printers, full-color plain paper fax machines, etc. using direct or indirect electrophotographic multicolor image development systems.

1 Conductor container (cage)
2 Metal mesh 3 Electrophotographic developer 4 Toner 5 Nozzle 10 Electrostatic latent image carrier (photosensitive drum)
10K Black electrostatic latent image carrier 10Y Yellow electrostatic latent image carrier 10M Magenta electrostatic latent image carrier 10C Cyan electrostatic latent image carrier 14 Support roller 15 Support roller 16 Support roller 17 Intermediate transfer member cleaning Device 18 Image forming means 20 Charging roller 21 Exposure device 22 Secondary transfer device 23 Roller 24 Secondary transfer belt 25 Fixing device 26 Fixing belt 27 Pressure roller 28 Sheet reversing device 30 Exposure device 32 Contact glass 33 First traveling body 34 First 2 traveling body 35 imaging lens 36 reading sensor 40 developing device 41 developing belt 42K electrophotographic developer container 43K electrophotographic developer supply roller 44K developing roller 45K black developing unit 42Y electrophotographic developer container 43Y electrophotographic Developer supply roller 44Y development Roller 45Y Yellow development unit 42M Electrophotographic developer container 43M Electrophotographic developer supply roller 44M Development roller 45M Magenta development unit 42C Electrophotographic developer container 43C Electrophotographic developer supply roller 44C Development roller 45C Cyan Development unit 49 Registration roller 50 Intermediate transfer member 51 Roller 52 Separation roller 53 Manual feed path 54 Manual feed tray 55 Switching claw 56 Ejection roller 57 Ejection tray 58 Corona charger 60 Cleaning device 61 Development device 62 Transfer charger 63 Cleaning device 64 Static eliminator 70 Static elimination lamp 80 Transfer roller 90 Cleaning blade for intermediate transfer member 95 Recording medium 100 Image forming apparatus 101 Electrostatic latent image carrier 102 Charging means 103 Exposure by exposure means 104 Development means 10 Recording medium 107 Cleaning means 108 Transfer means 120 Tandem developer 130 Document table 142 Paper feed roller 143 Paper bank 144 Paper feed cassette 145 Separation roller 146 Paper feed path 147 Conveyance roller 148 Paper feed path 150 Copier main body 160 Charging device 200 Feed Paper table 300 Scanner 400 Automatic document feeder (ADF)
L exposure

Japanese Patent No. 2744790 JP-A-8-6307 Japanese Patent No. 3654778 Japanese Patent No. 2998633 Japanese Patent No. 3374656 JP 2008-40270 A

Claims (9)

An electrophotographic carrier having a core material and a coating layer obtained by crosslinking the binder resin precursor on the surface of the core material,
The binder resin precursor contains at least (A) a diisocyanate compound, (B) an amino group-modified polysiloxane represented by the following general formula (1), and (C) a polyfunctional epoxy resin. ,
The content (mc) of the (C) polyfunctional epoxy resin in the binder resin precursor is based on the total content (mT) of the (A) diisocyanate compound and the (B) both-terminal amino group-modified polysiloxane. A carrier for electrophotography , wherein the mass ratio (mc / mT) is 0.005 to 0.1 .
_{NH 2 (CH 2) 3 (} R 2 SiO) n SiR 2 (CH 2) 3 NH 2 Formula (1)
However, in the said General formula (1), R is a hydrogen atom, a halogen atom, a C1-C10 alkoxy group or an allyloxy group, a C1-C20 saturated hydrocarbon group, a C2-C20 alkenyl group. , An aralkyl group having 6 to 20 carbon atoms, an aryl group having 7 to 20 carbon atoms, a silicon atom-containing group having 1 to 10 silicon atoms, and a substituent thereof, which may be the same as each other, May be different. n represents the calculated chain length calculated from the molecular weight. An electrophotographic carrier having a core material and a coating layer obtained by crosslinking the binder resin precursor on the surface of the core material,
The binder resin precursor contains at least (A) a diisocyanate compound, (B) an amino group-modified polysiloxane represented by the following general formula (1), and (C) a polyfunctional epoxy resin. ,
The electrophotographic carrier, wherein the polyfunctional epoxy resin (C) is at least one of a phenol novolac epoxy resin, a cresol novolac epoxy resin, and derivatives thereof .
_{NH 2 (CH 2) 3 (} R 2 SiO) n SiR 2 (CH 2) 3 NH 2 Formula (1)
However, in the said General formula (1), R is a hydrogen atom, a halogen atom, a C1-C10 alkoxy group or an allyloxy group, a C1-C20 saturated hydrocarbon group, a C2-C20 alkenyl group. , An aralkyl group having 6 to 20 carbon atoms, an aryl group having 7 to 20 carbon atoms, a silicon atom-containing group having 1 to 10 silicon atoms, and a substituent thereof, which may be the same as each other, May be different. n represents the calculated chain length calculated from the molecular weight. (B) The electrophotographic carrier according to claim 1, wherein the both-terminal amino group-modified polysiloxane is two or more terminal-terminal amino group-modified polysiloxanes having different chain lengths n. The electrophotographic carrier according to claim 1, wherein the coating layer contains fine particles. An electrophotographic developer comprising the electrophotographic carrier according to claim 1 and a toner. An electrostatic latent image forming step of forming an electrostatic latent image on the surface of the electrostatic latent image carrier;
The electrostatic latent image formed on the surface of the electrostatic latent image carrier is developed with a developer to form a visible image.
Developing process
A transfer step of transferring the visible image to a recording medium;
A fixing step of fixing the visible image transferred to the recording medium;
An image forming method according to claim 5, wherein the developer is the electrophotographic developer according to claim 5. An electrostatic latent image carrier;
An electrostatic latent image forming means for forming an electrostatic latent image on the surface of the electrostatic latent image carrier;
Developing means for developing an electrostatic latent image formed on the surface of the electrostatic latent image carrier with an electrophotographic developer to form a visible image;
Transfer means for transferring the visible image to a recording medium;
Fixing means for fixing the visible image transferred to the recording medium;
An image forming apparatus comprising: the electrophotographic image forming apparatus according to claim 5, wherein the electrophotographic developer is the electrophotographic developer according to claim 5. An electrostatic latent image carrier;
Developing means for developing an electrostatic latent image formed on the surface of the electrostatic latent image carrier using an electrophotographic developer to form a visible image;
A process cartridge for an electrophotographic image forming apparatus comprising: the electrophotographic developer according to claim 5, wherein the electrophotographic developer is an electrophotographic developer according to claim 5. An image forming apparatus according to claim 7 and a process cartridge according to claim 8, wherein the image forming apparatus is detachable and contains the developer for electrophotography according to claim 5. Container with developer.