JP2016031422A - Developing device and developing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device and a developing method with which a reduction in image density due to charge-up in a low-humidity environment can be suppressed even after a long-term printing, and the occurrence of scattering in a high-temperature and high-humidity environment can be suppressed, so as to provide good images.SOLUTION: There is provided a developing device including a developer carrier formed by using a specific resin composition and a specific developer, where the developer is a toner containing a binder resin, colorant, and wax, and the binder resin is obtained through polymerization with a polyester resin as a main component in the presence of the wax, and through a process of cooling to solidify the polyester resin after the polymerization, melting and kneading a solid into a molten state to introduce to a thin-film evaporator, and distilling off a volatile component. There is also provided a developing method using the developing device.SELECTED DRAWING: None

Description

  The present invention relates to a developing device and a developing method used in an electrophotographic image forming apparatus.

  In recent years, there has been a demand for obtaining high-quality electrophotographic images continuously for a long period of time.

  However, when development is repeatedly performed over a long period of time, a phenomenon in which the toner on the developer carrying member is excessively charged (so-called charge-up phenomenon) may occur.

  Toner that is excessively charged due to the charge-up phenomenon is attracted electrostatically and strongly to the surface of the developer carrier, so when the charge-up phenomenon occurs, the toner moves from the developer carrier to the electrostatic latent image on the photoreceptor. It becomes difficult and developability tends to be lowered.

  Further, when the charge-up phenomenon occurs, the lower layer toner that is in contact with the surface of the developer carrier among the toner layers carried on the developer carrier is strongly attracted to the developer carrier. Therefore, the contact between the toner located in the upper layer and the surface of the developer carrying member is hindered, and the toner in the upper layer becomes difficult to be charged. As described above, the generation of the toner that is not sufficiently charged may reduce the toner development amount and the image density.

  Further, this charge-up phenomenon is likely to occur in a low humidity environment where the toner is easily charged.

  As a method for solving such a problem, Patent Documents 1 and 2 propose the use of a developer carrier having a surface layer containing a charge control agent having the same polarity as the charge polarity of the toner.

  Specifically, Patent Document 1 discloses a developer carrier having a surface layer formed using a paint containing a quaternary phosphonium salt and a specific phenol resin.

  Patent Document 2 discloses a developing device in which a developer carrying body containing a quaternary phosphonium salt in a surface layer and a magnetic toner having a predetermined magnetic property are combined.

JP 2010-55072 A JP 2010-32771 A

  The inventors of the present invention have confirmed that the inventions according to Patent Documents 1 and 2 can suppress the toner charge-up and suppress the decrease in image density due to the charge-up phenomenon.

  However, in the process of developing the electrostatic latent image formed on the photoreceptor, the phenomenon that the toner adheres to the periphery of the electrostatic latent image portion (hereinafter, this phenomenon is also referred to as “scattering”) is still improved. We gained recognition that there is room for. This phenomenon was particularly noticeable when outputting an image in a high temperature and high humidity environment.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a developing device and a developing method capable of achieving both high-level suppression of developer charge-up and suppression of toner scattering.

According to the present invention, a developer, a developer container for containing the developer, a developer carrier for carrying and transporting the developer on the surface, and a developer on the developer carrier A developer layer thickness regulating member for regulating the amount of the developer, wherein the developer carrier has a base and a resin layer formed on the surface of the base, and the resin layer Is a resin (A) having at least one structure selected from the group consisting of —NH ₂ group, ═NH group and —NH— bond in the structure, and quaternary phosphonium having a structure represented by the following formula (1) It is formed using a resin composition containing a salt and conductive fine particles, and the developer is a toner containing a binder resin, a colorant and a wax, and the binder resin is: Polymerized in the presence of the wax with polyester resin as the main component A developing device characterized by being solidified by cooling after polymerization, melted and kneaded of the solidified product, introduced into a thin film evaporator in a molten state, and distilled off a volatile component Is provided.

(In the formula (1), R ₁ to R ₃ are each independently an optionally substituted alkyl group having 1 to 4 carbon atoms, which may have a substituent phenyl group and a substituted group R ₄ is an optionally substituted benzyl group, and R ₄ has an optionally substituted alkyl group having 1 to 16 carbon atoms, an optionally substituted alkenyl group, and a substituent. Or an optionally substituted alkynyl group, an optionally substituted phenyl group or an optionally substituted benzyl group, and X ⁻ is a halogen ion, OH ⁻ , an organic acid ion or an inorganic acid ion. An anion selected from
Further, according to the present invention, the developer is transported to the developing region facing the electrostatic latent image carrier using the developing device, and is carried on the electrostatic latent image carrier by the transported developer. There is provided a developing method characterized in that the developed electrostatic latent image is developed.

  According to the present invention, even when printing is performed for a long period of time, it is possible to achieve good image quality by suppressing the occurrence of scattering in a high temperature and high humidity environment while suppressing a decrease in image density due to a charge-up phenomenon in a low humidity environment. Can be provided.

1 is a schematic cross-sectional view of a thin film evaporator used for producing a developer according to the present invention. It is a schematic diagram showing an example of a developing device according to the present invention. It is a schematic diagram showing an example of a developing device according to the present invention.

  Hereinafter, the present invention will be described in detail.

  The present invention regulates a developer, a developer container for containing the developer, a developer carrier for carrying and transporting the developer on the surface, and a developer amount on the developer carrier. The present invention relates to a developing device provided with a developer layer thickness regulating member and a developing method using the developing device.

Hereinafter, the developer carrier and the developer constituting the developing device will be described.
<Developer carrier>
A developer carrier used in the developing device according to the present invention includes a base and a resin layer formed on the surface of the base.

  Further, a magnetic member may be provided inside the base.

The resin layer includes a resin (A) having at least one structure selected from the group consisting of —NH ₂ group, ═NH group and —NH— bond in the structure, and a fourth structure having the structure represented by the following formula (1). It is formed using a resin composition containing a secondary phosphonium salt and conductive fine particles.

In the formula (1), R _{1 to} R ₃ each independently represent an optionally substituted alkyl group having 1 to 4 carbon atoms, an optionally substituted phenyl group, and a substituent. Any of the benzyl groups that may have. R ₄ has an optionally substituted alkyl group having 1 to 16 carbon atoms, an alkenyl group that may have a substituent, an alkynyl group that may have a substituent, and a substituent. It may be either a phenyl group which may be substituted or a benzyl group which may have a substituent. X ⁻ is an anion selected from halogen ion, OH ⁻ , organic acid ion or inorganic acid ion.

  In the present invention, as described above, the conductive resin layer is formed using the resin composition containing the resin (A) containing a specific group in the structure and the quaternary phosphonium salt having a specific structure. This is important in order to suppress the developer charge-up phenomenon.

  In general, a quaternary phosphonium salt is used as a charge control agent for increasing the triboelectric charge amount of a positively chargeable toner. Accordingly, when the quaternary phosphonium salt is contained in the resin layer of the developer carrying member, the positive chargeability of the resin layer is increased. Therefore, the effect of increasing the negative charging property of the toner in contact with the resin layer of the developer carrying member is improved. There is. However, in the resin layer formed using the resin composition containing the quaternary phosphonium salt and the resin (A) having a specific structure, the resin layer is formed by the interaction between the resin and the quaternary phosphonium salt. It was found that the negative charge imparting property to the toner is suppressed. Therefore, by using a developer carrier having a resin layer formed by using a resin composition containing the quaternary phosphonium salt and the resin (A) having a specific structure, an excess of negatively chargeable toner can be obtained. It is possible to suppress the triboelectric charge and suppress the charge-up phenomenon.

  The reason for the behavior of the resin layer according to the present invention is not clear, but the present inventors presume as follows.

When the resin composition composed of the quaternary phosphonium salt and the resin (A) is heated and cured, the interaction between the quaternary phosphonium salt and the —NH ₂ group, ═NH group or —NH— bond causes The anion part is incorporated into the resin skeleton. As a result, it is presumed that the triboelectric charging polarity of the anion portion of the quaternary phosphonium salt is developed, and the charging of the negatively chargeable toner is suppressed.

[Quaternary phosphonium salt having the structure represented by the formula (1)]
The quaternary phosphonium salt having the structure represented by the above formula (1) will be described below.

The quaternary phosphonium salt according to the present invention has a structure represented by the above formula (1). Among them, at least three functional groups among R _{1 to} R ₄ are a butyl group which may have a substituent, a phenyl group which may have a substituent, or a benzyl group which may have a substituent. It is preferable that When at least three functional groups among R _{1 to} R ₄ are the above functional groups, not only the dispersibility of the conductive fine particles in the resin layer is improved, but also the dispersibility of the quaternary phosphonium salt is improved. It becomes possible to make it. As a result, the toner can be uniformly and stably charged, and the charge-up phenomenon can be further suppressed.

  Moreover, it is preferable that the structure of the cation part of Formula (1) is a structure shown by following formula (2). When the structure of the cation portion is the structure represented by the formula (2), the affinity with the resin in the resin layer of the developer carrying member can be further increased. Therefore, since aggregation of the quaternary phosphonium salt in the resin layer can be suppressed, the dispersibility of the quaternary phosphonium salt can be further improved.

As the organic acid ion or inorganic acid ion of X ⁻ in the above formula (1), an organic sulfate ion, an organic sulfonate ion, an organic phosphate ion, a molybdate ion, a tungstate ion, a molybdenum atom or a heteropolyacid containing a tungsten atom Ions. Among the above-mentioned anions, X ⁻ is preferably a halogen ion because the charge imparting property to the toner when added to the resin (A) is stable. Of the halogen ions, bromine ions are more preferred. When X ⁻ is bromine ion, the effect of lowering the charge amount of the toner appears more remarkably, so that the developer charge-up phenomenon can be more easily suppressed.

  Table 1 lists quaternary phosphonium salts suitably used in the present invention. Of course, the present invention is not limited to these.

  In addition, a quaternary phosphonium salt is contained in the resin layer by measuring a sample collected by grinding the surface of the developer carrier or extracting with a solvent such as chloroform by GC-MS (gas chromatograph mass spectrometer). It is possible to confirm that

[Resin (A)]
As the binder resin used for the resin layer, a resin (A) having at least one structure selected from —NH ₂ group, ═NH group and —NH— bond is used. Among them, the following resins are preferable.

  Phenol resin, polyamide resin produced using a nitrogen-containing compound as a catalyst in the production process; epoxy resin, polyamide resin using polyamide as a curing agent, or a copolymer partially containing these resins.

  These resins are preferable because they not only have excellent adhesion to the substrate of the developer carrying member and wear resistance, but can impart an appropriate triboelectric charge to the toner. Furthermore, it is possible to further improve the wear resistance by modifying the resin by crosslinking reaction with other resins, prepolymers and polymers.

  Moreover, in this invention, the phenol resin which is a thermosetting resin which has sufficient mechanical strength among said resin is preferable from a durable viewpoint.

In order for the phenol resin to have any of —NH ₂ group, ═NH group and —NH— bond, it is preferably produced using a nitrogen-containing compound such as ammonia as a catalyst in the phenol resin production process. . The nitrogen-containing compound exists in the phenol resin even after the reaction is completed. For example, when polymerized in the presence of an ammonia catalyst, it has been generally confirmed that an intermediate called ammonia resol is formed, and even after the reaction is completed, the structure represented by the following formula (3) Is present in the phenolic resin.

  The nitrogen-containing compound used as the catalyst may be either an acidic catalyst or a basic catalyst.

  For example, the following are mentioned as an acidic catalyst.

  Ammonium salts or amine salts such as ammonium sulfate, ammonium phosphate, ammonium sulfamate, ammonium carbonate, ammonium acetate, and ammonium maleate.

  Moreover, the following are mentioned as a basic catalyst.

  Ammonia; dimethylamine, diethylamine, diisopropylamine, diisobutylamine, diamylamine, trimethylamine, triethylamine, tri-n-butylamine, triamylamine, dimethylbenzylamine, diethylbenzylamine, dimethylaniline, diethylaniline, N, N-din-butyl Aniline, N, N-diamilaniline, N, N-di-t-amylaniline, N-methylethanolamine, N-ethylethanolamine, diethanolamine, triethanolamine, dimethylethanolamine, diethylethanolamine, ethyldiethanolamine, n -Amino such as butyl diethanolamine, di-n-butylethanolamine, triisopropanolamine, ethylenediamine, hexamethylenetetramine Compound: Pyridine such as pyridine, α-picoline, β-picoline, γ-picoline, 2,4-lutidine, 2,6-lutidine and derivatives thereof; quinoline compound, imidazole, 2-methylimidazole, 2,4-dimethyl Nitrogen-containing heterocyclic compounds such as imidazole and its derivatives such as imidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-heptadecylimidazole.

The resin (A) is analyzed by a measuring device such as IR (infrared absorption spectroscopy) or NMR (nuclear magnetic resonance spectroscopy), and its structure is -NH ₂ group, = NH group and -NH- bond. It is possible to confirm that it has either.

  Further, the resin layer of the developer carrying member preferably contains 1 part by mass or more and 60 parts by mass or less of a quaternary phosphonium salt with respect to 100 parts by mass of the resin (A). More preferably. When the content of the quaternary phosphonium salt is 1 part by mass or more, the charge-up of the toner can be further suppressed. In addition, if the content of the quaternary phosphonium salt is 60 parts by mass or less, the developer carrier can maintain a sufficient negative charging performance with respect to the toner, so that a decrease in image density due to a decrease in the toner charge amount is suppressed. It becomes possible to do.

[Conductive fine particles]
The developer carrying member according to the present invention contains conductive fine particles in the resin layer in order to adjust the resistance value of the resin layer. Examples of the conductive fine particles used at this time include the following.

  Fine powders of metals such as aluminum, copper, nickel and silver; conductive metal oxides such as antimony oxide, indium oxide, tin oxide, titanium oxide, zinc oxide, molybdenum oxide and potassium titanate; crystalline graphite; various carbon fibers Conductive carbon black such as furnace black, lamp black, thermal black, acetylene black, channel black; metal fiber. These conductive fine particles may be used in combination.

  Among these, conductive carbon black, especially conductive amorphous carbon, is particularly excellent in electrical conductivity, and can be given a certain degree of conductivity by simply filling the polymer material with conductivity and controlling the amount added. Is preferable. Further, the dispersion stability and coating stability are also improved due to the thixotropic effect of the paint.

  Crystalline graphite is preferable because it has excellent conductivity and, when added to the resin layer, surface lubricity increases and the toner contamination resistance of the resin layer is improved.

  Although the addition amount of electroconductive fine particles changes also with the particle sizes, it is preferable to set it as the range of 1 to 100 mass parts with respect to 100 mass parts of binder resin in a resin layer. If it is 1 part by mass or more, it is possible to reduce the resistance and high lubricity of the resin layer, and if it is 100 parts by mass or less, the resistance (abrasion resistance) of the resin layer is not greatly reduced, and the resistance is reduced. The value can be suitably reduced.

The volume resistivity of the resin layer of the developer carrying member according to the present invention, 1 × preferably ¹⁰ at ^-1 Omega · cm or more 1 × 10 ³ Ω · cm or less, 1 × ^{10 -1 Ω} · cm or more More preferably, it is 1 × 10 ² Ω · cm or less. If the volume resistance value is 1 × 10 ⁻¹ Ω · cm or more or 1 × 10 ³ Ω · cm or less, the toner can be more appropriately charged.

[Roughness imparting particles]
The resin layer according to the present invention may contain unevenness-imparting particles for forming unevenness on the surface of the resin layer as necessary. Examples of the unevenness imparting particles include the following.

  Vinyl polymers and copolymers such as polymethyl methacrylate, polyethyl acrylate, polybutadiene, polyethylene, polypropylene, polystyrene; resin particles such as benzoguanamine resin, phenol resin, polyamide resin, fluororesin, silicone resin, epoxy resin, polyester resin Oxide particles such as alumina, zinc oxide, silicone, titanium oxide and tin oxide; carbon particles; conductive particles such as resin particles subjected to a conductive treatment.

  In addition, it is also possible to use an organic compound such as an imidazole compound in the form of particles. In this case, the imidazole compound can also serve to impart a triboelectric charge to the toner.

  In addition, by treating the surface of the spherical resin particles used as irregularity imparting particles with inorganic fine powder, dispersibility in the paint and uniformity of the coating surface can be improved, and imparting triboelectric charge to toner and developing It is possible to improve the stain resistance, wear resistance and mechanical strength of the surface of the agent carrier. The spherical resin particles defined here are resin particles having a major axis / minor axis ratio measured from an observation image of an electron microscope of 1.0 to 1.2 on average.

  The volume average particle diameter of the spherical resin particles is preferably 2.0 μm or more and 20.0 μm or less, and more preferably 4.0 μm or more and 15.0 μm or less. When the volume average particle diameter of the spherical resin particles is 2.0 μm or more, it is possible to form uniform unevenness in the resin layer for sufficiently transporting the toner to the development area. When the volume average particle diameter of the spherical resin particles is 20.0 μm or less, the unevenness-imparting particles do not protrude too much from the surface of the resin layer, and the amount of toner carried on the developer carrying member is maintained at an appropriate level. Uniform triboelectric charging can be imparted. Further, when a bias voltage is applied to the developer carrying member, it is possible to suppress charge leakage to the photosensitive member.

  The surface roughness of the resin layer of the developer carrying member according to the present invention is preferably 0.30 μm or more and 2.50 μm or less in arithmetic average roughness (Ra) defined in JIS B0601-2001. If it is 0.30 μm or more, it is possible to sufficiently transport the toner to the development area, and image defects due to insufficient image density due to insufficient toner and uneven coating amount of toner on the surface of the developer carrier are caused. Can be suppressed. Further, if it is 2.50 μm or less, it is possible to make the toner imparted with frictional charge uniformly, thereby suppressing the occurrence of streak unevenness, reversal fogging, and low image density due to insufficient frictional charging.

[Resin layer thickness]
The film thickness of the resin layer is preferably in the range of 5.0 μm or more and 30.0 μm or less, although the suitable film thickness varies depending on the development method. If the film thickness is 5.0 μm or more, the resin layer covers the entire surface of the substrate without any gaps, so that the substrate is not partially exposed, and the developer can be uniformly charged with friction. . In addition, when the film thickness is 30.0 μm or less, it is easy to stably control the surface roughness.

[Method for producing developer carrier]
As the substrate used in the developer carrying member according to the present invention, there are a cylindrical member, a columnar member, a belt-like member, etc. In a developing method that is not in contact with the photosensitive member, a rigid cylindrical tube such as a metal is used. Alternatively, a solid bar is preferably used. As such a substrate, a non-magnetic metal or alloy such as aluminum, stainless steel, or brass is molded into a cylindrical shape or a cylindrical shape, and is subjected to polishing, grinding, or the like. These substrates are used after being molded or processed with high accuracy in order to improve the uniformity of the image. For example, the straightness in the longitudinal direction is preferably 30 μm or less, more preferably 20 μm or less, and still more preferably 10 μm or less. Further, the fluctuation of the gap between the developer carrier and the photosensitive member, for example, the fluctuation of the gap between the vertical surface when the developer carrier is rotated by abutting against the vertical surface through a uniform spacer is more than 30 μm. The following is preferable, preferably 20 μm or less, and more preferably 10 μm or less. In view of material cost and ease of processing, the substrate is preferably aluminum.

  As a method for forming a resin layer according to the present invention, for example, a component for forming a resin layer is dispersed and mixed in a solvent to form a paint, applied to the substrate surface to form a coating film, and then dried, solidified or cured Can be formed. For dispersion mixing of each component, a known media dispersing device such as a ball mill, a sand mill, an attritor, or a bead mill, or a known medialess dispersing device using a collision type atomization method or a thin film swirling method can be suitably used. . As a coating method for the dispersed paint, known methods such as a dipping method, a spray method, a roll coating method, and an electrostatic coating method can be applied.

<Toner (Developer)>
According to the study by the present inventors, in order to obtain the effect of the present invention, not only the toner carrying-up is suppressed by using the developer carrier, but also the charge amount is high and the charge distribution is uniform. It has been found that it is necessary to use a toner capable of being used simultaneously with the developer carrier.

  The toner (developer) according to the present invention will be described below.

  The developer according to the present invention is a toner containing a binder resin, a colorant and a wax. The binder resin is polymerized in the presence of the wax with a polyester resin as a main component. After the polymerization, the resin is cooled and solidified, and the solidified product is melt-kneaded and introduced into a thin film evaporator in a molten state. And obtained through a step of distilling off the volatile components.

  In order to suppress the scattering of the toner and improve the image quality of the electrophotographic image, it is necessary to provide the toner with a high charge amount and a uniform charge distribution within a range where the charge-up phenomenon does not occur.

  In order to increase the charge amount of the toner, it is effective to use a binder resin whose main component is a polyester resin having excellent charging performance.

  At the same time, it is important to consider a component that reduces the charge amount of the toner so that the toner is not excessively charged.

  The present inventors paid attention to wax as a component for reducing the charge amount of the toner.

  Wax is contained in the toner in order to improve the low-temperature fixability and releasability of the toner. On the other hand, wax is a material that is hard to be charged as compared with a binder resin of toner. For this reason, if the wax is unevenly distributed on the toner surface, the charge amount of the toner is reduced and the development cannot be performed sufficiently, so that the image density may be lowered. Also, if the amount of wax on the toner surface differs for each toner particle, a difference occurs in the charge amount for each toner particle, so that the toner charge amount distribution is likely to spread. When the charge distribution of the toner spreads, only the toner with a high charge amount is selectively developed, so-called selective development occurs. When printing is performed for a long time, the remaining toner with a low charge amount is developed. Will be. A toner having a low charge amount is unlikely to behave along an electric field formed between the developer carrying member and the photosensitive member during development. Therefore, particularly in a high-temperature and high-humidity environment where the toner charge amount tends to be low, the amount of toner adhering to the non-latent image portion on the photoreceptor is likely to increase, and the image quality is likely to deteriorate due to the scattering of the toner.

  Therefore, it is important to increase the dispersibility of the wax in the toner so that the wax does not locally exist on the toner surface, thereby obtaining a toner having a high charge amount and a uniform charge amount distribution. Become.

  Furthermore, a phenomenon that the wax existing in the toner also moves to the toner surface due to the use environment or printing for a long period of time is observed. In particular, in a high-temperature and high-humidity environment, the molecules that make up the wax are easy to move, so the phenomenon of the wax moving to the toner surface is more prominent, thereby reducing the charge amount of the toner or charging the toner. The quantity distribution sometimes spreads.

  Therefore, it is important to maintain the dispersibility of the wax in the toner even when printing is performed for a long time in a high temperature and high humidity environment.

  Accordingly, the present inventors have intensively studied to increase the dispersibility of the wax and make it difficult for the wax to migrate to the toner surface even in a high temperature and high humidity environment.

  As a result, the present inventors polymerized the binder resin according to the present invention in the presence of wax, cooled and solidified after the polymerization, melted and kneaded the solidified product, and introduced it into a thin film evaporator in a molten state. The present inventors have found that it is important that the volatile component is obtained through a process of distilling off volatile components. By using such a binder resin, the dispersion of the wax in the toner can be made uniform, and a toner having excellent charging performance and a uniform charge distribution can be obtained.

  Here, the polymerized resin obtained by polymerization in the presence of wax is referred to as an intermediate binder resin. By polymerizing in the presence of the wax to produce the intermediate binder resin, the wax can be finely and uniformly dispersed in the intermediate binder resin. In particular, when a wax having one or more functional groups (polar groups) selected from an ester group, a carboxyl group, and a hydroxyl group is used, compatibility with a binder resin having a polar polyester resin as a main component is improved. . Therefore, it is preferable because the dispersibility of the wax in the binder resin is further improved.

  It is also important to cool and solidify the intermediate binder resin after polymerization. A product obtained by cooling and solidifying the intermediate binder resin is called a solidified product. By cooling and solidifying the intermediate binder resin after polymerization, reaggregation of the finely and uniformly dispersed wax can be effectively suppressed. If reaggregation of wax occurs in the binder resin, the dispersibility of the wax inside the toner is lowered when the toner is produced, and the wax tends to be unevenly distributed on the toner surface.

  Furthermore, it is important to melt-knead the solidified product. The resin after melt-kneading will be referred to as post-kneading resin. By melt-kneading the solidified product and applying shear to the resin, the finely and uniformly dispersed wax can be uniformly dispersed throughout the resin after kneading. The solidified product may be pulverized before proceeding to the next step.

  Subsequently, it is important to go through the step of introducing the melted and kneaded resin into the thin film evaporator and distilling off the volatile components. Since the inside of the thin film evaporator is in a heated and reduced pressure state, the resin after kneading can be further polymerized by introducing the resin after kneading into the thin film evaporator. It is thought that it is taken in and fixed so as to be included in the structure.

  As described above, the binder resin mainly composed of the polyester-based resin according to the present invention is polymerized in the presence of the wax, cooled and solidified after the polymerization, and the solidified product is melt-kneaded into the thin film evaporator in a molten state. It is obtained through a step of introducing and distilling off volatile components. As a result, it is considered that the wax can be finely dispersed uniformly throughout the binder resin, and can be fixed by being included in the molecular structure of the binder resin.

  Even if the toner thus obtained is exposed to a high temperature in a printing machine under high temperature and high humidity or for a long time, the wax is included in the molecular structure of the binder resin. Migration to the toner surface is suppressed. For this reason, toner charging failure can be suppressed and the charge distribution becomes uniform, so that it is possible to obtain a toner that is difficult to decrease in density and that can provide good image quality.

  When the binder resin obtained without adding the wax at the time of polymerization of the binder resin and adding the wax only when producing the toner, it is difficult to finely disperse the wax in the binder resin. The composition of the toner surface tends to be non-uniform. As a result, the charging performance of the toner deteriorates, and the image quality and the density of the solid black image may decrease.

  In addition, when the intermediate binder resin after polymerization is not cooled and solidified once, the wax easily re-aggregates even if the wax is finely dispersed in the intermediate binder resin.

  In other words, once the intermediate binder resin after polymerization is melt-kneaded without being cooled and solidified, it takes a long time for the resin to be exposed to heat during the period from polymerization to melt-kneading, so that reaggregation between waxes tends to occur. .

  Further, when the solidified product is not melt-kneaded, it is difficult to uniformly disperse the wax throughout the resin.

  That is, when the solidified product is passed through a thin film evaporator without being melt-kneaded, the distribution of the wax in the resin is not uniform. As a result, the toner becomes a toner in which wax is localized when the toner is manufactured, and the uniformity of the charge distribution is impaired, so that the image quality is likely to be lowered.

  Further, when the thin film evaporator is not used, the wax finely dispersed throughout the binder resin is less likely to be included in the molecular structure of the binder resin. Therefore, when the toner is exposed to a high temperature in the printing machine several times in a high temperature and high humidity environment or for a long period of printing, the wax moves to the toner surface, and the density tends to decrease due to poor charging. Further, when a thin film evaporator is not used, a volatile component having a small molecular weight tends to remain in the binder resin. Volatile components having a low molecular weight tend to plasticize the binder resin. When the volatile component plasticizes the binder resin, the molecular structure of the binder resin containing the wax becomes easy to move, and the wax becomes easy to move in the binder resin. As a result, when the toner is exposed to a high temperature in the printing machine at high temperature and high humidity or for a long time, the toner tends to move to the surface of the toner, and the density is likely to decrease due to poor charging.

[Toner binder resin]
The binder resin used in the toner according to the present invention contains a polyester resin as a main component.

  The polyester resin is obtained by reacting the following alcohol component and acid component.

  Examples of the divalent alcohol component include ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1, 6-hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, hydrogenated bisphenol A, bisphenol represented by the following formula (A) and derivatives thereof; diols represented by the following formula (B) Is:

  (In the formula, R is an ethylene or propylene group, x and y are each an integer of 0 or more, and the average value of x + y is 0 to 10.)

  Examples of the divalent acid component include benzene dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and phthalic anhydride or anhydrides thereof, lower alkyl esters; alkyl dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and azelaic acid. Dicarboxylic acids and derivatives thereof such as acids or anhydrides thereof, lower alkyl esters; alkenyl succinic acids or alkyl succinic acids such as n-dodecenyl succinic acid and n-dodecyl succinic acid, or anhydrides, lower alkyl esters thereof, and the like.

  Further, a trivalent or higher alcohol component or a trivalent or higher acid component may be used as necessary.

  Examples of the trihydric or higher polyhydric alcohol component include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butane. Triol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxybenzene, etc. Is mentioned.

  Examples of the trivalent or higher polyvalent carboxylic acid component include pyromellitic acid, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2 , 4-Naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, tetra (methylenecarboxyl) methane 1,2,7,8-octanetetracarboxylic acid, empol trimer acid, and their anhydrides, lower alkyl esters;

(Wherein X is an alkylene group or alkenylene group having 5 to 30 carbon atoms having one or more side chains having 3 or more carbon atoms)
And polycarboxylic acids such as anhydrides and lower alkyl esters thereof and derivatives thereof. Of these, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, anhydrides thereof, and lower alkyl esters are preferable.

  The addition amount of the alcohol component used in the present invention is preferably 40 to 60 mol%, more preferably 45 to 55 mol%, based on all monomer components for obtaining the polyester resin. Further, the addition amount of the acid component is preferably 60 to 40 mol%, more preferably 55 to 45 mol%, based on all monomer components for obtaining the polyester resin. The trivalent or higher polyvalent component is preferably 0.1 to 60 mol% with respect to the total monomer components for obtaining the polyester resin.

  The polyester-based resin is usually obtained by generally known condensation polymerization. The polymerization reaction of the polyester resin is usually carried out in the presence of a catalyst at a temperature of about 150 to 300 ° C., preferably about 170 to 280 ° C. The reaction can be performed under normal pressure, reduced pressure, or increased pressure, but after reaching a predetermined reaction rate (for example, about 30 to 90%), the reaction system is 200 mmHg or less, preferably 25 mmHg or less, more preferably It is preferable to carry out the reaction by reducing the pressure to 10 mmHg or less.

  Examples of the catalyst include catalysts usually used for polyesterification, for example, metals such as tin, titanium, antimony, manganese, nickel, zinc, lead, iron, magnesium, calcium, germanium; and these metal-containing compounds (dibutyltin oxide, orthodibutyl). Titanate, tetrabutyl titanate, tetraisopropyl titanate, zinc acetate, lead acetate, cobalt acetate, sodium acetate, antimony trioxide, etc.).

  The binder resin of the toner according to the present invention may contain other resins as long as the polyester resin is a main component. As other resins used in the present invention, various conventionally known resins can be used, and vinyl resins are particularly preferable in terms of developability. If the polyester resin is the main component, other resins can be used alone or in combination of two or more with the polyester resin. Here, the main component means that it accounts for 50% by mass or more with respect to the total amount of the binder resin.

  Of the vinyl resins, styrene copolymers and styrene-acrylic copolymers are preferred.

  Furthermore, a desired resin can be produced by copolymerizing a monomer for adjusting the acid value of the resin with another monomer.

  Moreover, you may use a crosslinkable monomer further as a monomer used for preparation of vinyl-type resin. The content of the crosslinkable monomer is preferably 1 part by mass or less, preferably in the range of 0.001 to 0.05 parts by mass with respect to 100 parts by mass of the other vinyl monomer components.

As a manufacturing method for manufacturing a binder resin having a polyester-based resin and a resin other than the polyester-based resin, for example, the manufacturing methods shown in the following (a) to (d) can be given.
(A) A polyester resin and another resin are separately polymerized and then mixed to prepare a binder resin.
(B) A polyester resin is polymerized first, and another resin is polymerized in the presence of the polyester resin to produce a binder resin.
(C) The other resin is polymerized first, and the polyester resin is polymerized in the presence of the other resin to produce a binder resin.
(D) A polyester resin and another resin are simultaneously polymerized to produce a binder resin.

  Of the methods for producing the binder resins (a) to (d), the method (b) is particularly preferred.

  Further, the binder resin mainly composed of the polyester resin according to the present invention is preferably a hybrid resin in which a polyester resin and a vinyl resin are chemically bonded. Since the binder resin of the toner is the above-described hybrid resin, the wax is not only included in the molecular structure of the polyester resin but also included in the molecular structure of the vinyl resin, so that it is stronger. This is because the wax is fixed to the surface.

Examples of the hybrid resin include the following.
A polyester resin and a vinyl resin obtained by polymerizing a monomer component having a carboxylic acid ester group such as (meth) acrylic acid ester are formed by a transesterification reaction.
A polyester resin and a vinyl resin obtained by polymerizing a monomer component having a carboxylic acid group such as (meth) acrylic acid is formed by an esterification reaction.
A product formed by polymerizing a vinyl monomer in the presence of an unsaturated polyester resin polymerized using a monomer having an unsaturated group such as fumaric acid.

  Thus, the hybrid resin can be obtained by containing a monomer component capable of reacting with both resins in the vinyl resin and / or polyester resin and reacting them.

Moreover, as a manufacturing method of the hybrid resin used by this invention, the manufacturing method shown to the following (1) thru | or (5) can be mentioned, for example.
(1) After separately producing a vinyl resin and a polyester resin, dissolving and swelling in a small amount of an organic solvent, adding an esterification catalyst and an alcohol, and performing a transesterification reaction by heating, A method for obtaining a hybrid resin having a vinyl resin.
(2) A method of producing a hybrid resin having a polyester resin and a vinyl resin by reacting a polyester resin in the presence of the vinyl resin after the vinyl resin is produced. The hybrid resin is produced by a reaction between a vinyl resin (a vinyl monomer can be added if necessary) and a polyester monomer (alcohol, carboxylic acid) and / or a polyester resin. Also in this case, an organic solvent can be appropriately used.
(3) A method of producing a hybrid resin having a polyester resin and a vinyl resin by producing and reacting a vinyl resin in the presence of the polyester resin after production. The hybrid resin is produced by a reaction between a polyester resin (a polyester monomer can be added as necessary), a vinyl monomer, and / or a vinyl resin.
(4) A method of producing a hybrid resin by adding a vinyl monomer and / or a polyester monomer (alcohol, carboxylic acid) in the presence of these polymer components after the production of a vinyl resin and a polyester resin. Also in this case, an organic solvent can be appropriately used.
(5) A vinyl resin, a polyester resin, and a hybrid having a vinyl resin and a vinyl resin by mixing a vinyl monomer and a polyester monomer (alcohol, carboxylic acid) and continuously performing an addition polymerization and a condensation polymerization reaction. A method for producing a resin. Also in this case, an organic solvent can be appropriately used.

  In the production methods (1) to (5) above, the vinyl resin and / or the polyester resin can use a plurality of polymer components having different molecular weights and degrees of crosslinking.

  Among the production methods of the hybrid resins (1) to (5), the production method (3) is more preferable. In particular, those obtained by dissolving an unsaturated polyester resin capable of reacting with a vinyl monomer in a vinyl monomer and polymerizing a mixture of the polyester resin and the vinyl monomer by a bulk polymerization method are preferred.

  Bulk polymerization can increase the molecular weight of a vinyl resin, so that a polyester resin is hybridized to a vinyl resin with a high molecular weight to obtain a gel structure with a high molecular weight and a high molecular weight between cross-linking points. Is possible. Therefore, it becomes easy to take in the wax uniformly. In addition, since the bulk polymerization method does not require a step such as evaporation of the solvent as compared with the solution polymerization method, the binder resin can be obtained at low cost. Compared with the suspension polymerization method, it does not contain impurities such as dispersants, so it has less influence on the charging performance of the toner and provides excellent developability. ,preferable.

  When the hybrid resin in which the polyester resin and the vinyl resin are chemically bonded is contained, it is important that the polyester resin is an unsaturated polyester resin. The unsaturated polyester resin used in the hybrid resin preferably has a main peak in the molecular weight distribution of 2000 to 30000 (more preferably 3000 to 20000) in the GPC molecular weight distribution of THF (tetrahydrofuran) solubles. .

  Furthermore, a linear unsaturated polyester resin not containing a gel component is particularly preferable.

  The unsaturated polyester resin used in the present invention preferably has a number average molecular weight (Mn) of 2000 to 20000, more preferably 3000 to 10,000. In addition, the unsaturated polyester resin has excellent chargeability when the hydroxyl value is preferably 10 to 110 mgKOH / g (more preferably 15 to 90 mgKOH / g, more preferably 20 to 70 mgKOH / g). This is preferred for the sake of illustration.

  When bulk polymerization of vinyl monomers is carried out in the presence of unsaturated linear polyester resins, the main chain is a vinyl resin having a large molecular weight and high linearity, and the low molecular weight polyester resin is branched from the vinyl resin. A hybrid resin having a structure is obtained. Furthermore, the acid group and the hydroxyl group in the hybrid resin having this branched structure form an ester bond between molecules to form a gel component.

  As an acid component having an unsaturated group for obtaining an unsaturated polyester resin, unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid and itaconic acid, or anhydrides thereof, lower alkyl esters and the like are preferably used. These unsaturated dicarboxylic acids are preferably added at a ratio of 0.1 to 10 mol% (more preferably 0.3 to 5 mol%, still more preferably 0.5 to 3 mol%) with respect to the total acid component of the polyester monomer. It is to be. When the unsaturated dicarboxylic acid is added in this range, the unsaturated group concentration in the low molecular weight polyester molecule is optimal.

  When a hybrid resin in which a polyester resin and a vinyl resin are chemically bonded is contained, an unsaturated polyvalent carboxylic acid ester monomer is preferably used for the vinyl resin. Unsaturated polycarboxylic acid ester monomers include, for example, aliphatic unsaturated polycarboxylic acids such as fumaric acid, maleic acid, itaconic acid, mesaconic acid, citraconic acid, and aromatic unsaturated polycarboxylic acids such as phenylene diacrylic acid. And ester derivatives of polyvalent carboxylic acids.

  When a highly reactive unsaturated polyvalent carboxylic acid ester monomer is contained in the vinyl resin, the hydroxyl group in the hybrid resin having a branched structure and the ester between the molecules are reduced by the pressure during polymerization or by a thin film evaporator. Can be combined. When an unsaturated polyvalent carboxylic acid ester monomer is used for the vinyl resin, since the binder resin is connected by an ester bond between molecules, the wax is more easily included in the molecular structure and immobilized.

  In particular, in the present invention, an unsaturated dicarboxylic acid monoester is preferable in that the wax can be fixed in the binder resin by selecting a more reactive monomer.

  By depressurization during polymerization or with a thin film evaporator, an ester bond can be formed between the hydroxyl groups in the hybrid resin having a branched structure between the molecules. When an unsaturated dicarboxylic acid monoester having higher reactivity is used, an ester bond between the molecules of the binder resin can be efficiently formed, so that the probability that the wax is included and immobilized in the molecular structure is further increased.

  From the viewpoint of easily forming an anhydride group, the preferred unsaturated dicarboxylic acid monoester is a maleic acid monoester or a fumaric acid monoester, and more preferably a maleic acid monoester. Of these, monobutyl maleate is particularly preferred from the viewpoints of reactivity with copolymerized styrene or acrylate monomers and ease of formation of acid anhydrides.

[Kneading machine]
A kneader that can be used when melt-kneading the solidified product used in the present invention will be described. A well-known thing can be used as a kneading machine. The temperature of the molten binder resin discharged from the kneader is preferably 100 ° C. or higher and 200 ° C. or lower from the viewpoint of the share of the binder resin and the dispersibility of the wax.

[Thin film evaporator]
The thin film evaporator used in the present invention will be described.

  The thin film evaporator is not particularly limited as long as it is an apparatus that can depressurize the binder resin as a thin film, but FIG. 1 shows a preferable apparatus as the thin film evaporator. As shown in FIG. 1, the thin film evaporator includes a tank unit 10 and a rotating shaft 11 that rotates in the tank, and the rotating shaft 11 includes a stirring blade 12. Further, the thin film evaporator has a steam outlet 2, heating medium inlets 5 and 6, and heating medium outlets 3 and 4 that serve as a heating medium path for heating the tank 10. It is preferable that a plurality of stirring blades 12 are provided in the longitudinal direction of the rotating shaft 11 and have a certain degree of inclination in the circumferential direction. When the molten binder resin is introduced into the thin film evaporator from the inlet 1, the molten resin is uniformly dispersed on the inner wall surface of the tank 10 by the distributor 8. The distributor 8 and the agitating blade 12 have a narrow clearance with an inner wall surface, and are provided with a mechanism for forcibly thinning the film by being driven and rotated by an upper motor (not shown). Due to the rotating operation of the stirring blade 12, the molten resin thinned is forcibly transferred to the lower resin outlet 7 side while the surface layer portion is constantly updated. During this time, the molten resin is finally discharged from the outlet 7 through the screw 7 through the screw 7 while being decompressed and preferably heated in the tank 10.

  The thickness of the binder resin to be made into a thin film can be adjusted by the distance between the inner wall surface of the tank 10 and the stirring blade 12, but is preferably 1 to 5 mm, more preferably 2 to 4 mm.

  When the atmospheric pressure in the tank is preferably 0.3 Pa or more and 500 Pa or less, more preferably 0.5 Pa or more and 200 Pa or less, the polymerization of the binder resin proceeds in the tank, which is preferable for obtaining the effects of the present invention.

  The tank 10 is preferably heated. In particular, when heated at 50 ° C. or higher and 250 ° C. or lower, more preferably 100 ° C. or higher and 200 ° C. or lower, and even more preferably 150 ° C. or higher and 190 ° C. or lower, the polymerization of the binder resin easily proceeds. Further, the temperature of the binder resin when introducing the molten binder resin into the thin film evaporator is preferably matched with the temperature of the tank 10.

〔wax〕
The toner according to the present invention contains a wax.

  Specific examples of the wax include Biscol (registered trademark) 330-P, 550-P, 660-P, TS-200 (Sanyo Chemical Industries), high wax 400P, 200P, 100P, 410P, 420P, 320P, 220P, 210P, 110P (Mitsui Chemicals), Sazol H1, H2, C80, C105, C77 (Schumann Sazol), HNP-1, HNP-3, HNP-9, HNP-10, HNP-11, HNP- 12 (Nippon Seiki Co., Ltd.), Unilin (registered trademark) 350, 425, 550, 700, Unicid (registered trademark), Unicid (registered trademark) 350, 425, 550, 700 (Toyo Petrolite Co., Ltd.), Kirou, Beeswax, rice wax, candelilla wax, carnauba wax (available at Celerica NODA Inc.) And the like.

  Examples of the wax include those with a sharp molecular weight distribution using a press perspiration method, a solvent method, a recrystallization method, a vacuum distillation method, a supercritical gas extraction method, or a fused liquid crystal deposition method, and low molecular weight solid compounds ( Solid fatty acids, solid alcohols) and other impurities are preferably removed.

  The endothermic peak temperature (melting point) in the differential scanning calorimeter (DSC) measurement of the wax is preferably 60 ° C. or higher and 100 ° C. or lower, more preferably 70 ° C. or higher and 90 ° C. or lower. Within this range, it is possible to achieve both ease of fine dispersion during polymerization of the binder resin and suppression of wax transfer to the toner surface when the toner is left for a long time in a high temperature and high humidity environment.

  In the present invention, the wax is used together with a binder resin raw material (monomer or the like) and polymerized in the presence of the wax to be dispersed in the binder resin in advance.

  Two types of wax may be used.

  When two types of wax are used, it is preferable to use wax a having a melting point of 60 ° C. or higher and 100 ° C. or lower and wax b having a melting point higher than that of the wax a and 70 ° C. or higher and 120 ° C. or lower. It is preferable for obtaining developability.

  The total amount of wax contained in the toner is 2 to 20 parts by weight, more preferably 2 to 15 parts by weight, and still more preferably 2 parts by weight with respect to 100 parts by weight of the resin from the viewpoint of the balance between fixing performance and developability. Thru | or 10 mass parts.

[Colorant]
As the colorant according to the present invention, a black colorant, a yellow colorant, a magenta colorant, and a cyan colorant can also be used.

  As the black colorant, carbon black, grafted carbon, and those that are toned in black using the following yellow / magenta / cyan colorants can be used.

  As the yellow colorant, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, allylamide compounds, and the like are used.

  As the magenta colorant, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, perylene compounds, and the like are used.

  As the cyan colorant, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds, and the like can be used. These colorants can be used alone or in combination and further in the form of a solid solution.

  The colorant is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in the toner. The content of the colorant is preferably used by adding 1 to 20 parts by mass with respect to 100 parts by mass of the binder resin.

  The toner according to the present invention may be a magnetic toner containing a magnetic material in addition to the colorant. In this case, the magnetic material can also serve as a colorant.

  In the present invention, the magnetic material contained in the magnetic toner includes iron oxides such as magnetite, maghemite, and ferrite; metals such as iron, cobalt, and nickel, or these metals aluminum, cobalt, copper, lead, magnesium, tin And alloys of metals such as zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium, and mixtures thereof.

  These ferromagnetic materials preferably have an average particle size of 2 μm or less, more preferably 0.05 to 0.5 μm. Further, the content of the magnetic material is preferably 20 to 200 parts by mass, more preferably 40 to 150 parts by mass with respect to 100 parts by mass of the binder resin.

[Charge control agent]
The toner according to the present invention may contain a charge control agent.

  Examples of the negatively chargeable charge control agent for controlling the toner to be negatively chargeable include the following substances.

  For example, an organic metal compound and a chelate compound are effective, and there are a monoazo metal compound, an acetylacetone metal compound, an aromatic hydroxycarboxylic acid, and an aromatic dicarboxylic acid metal compound. Other examples include aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and metal salts thereof, anhydrides, esters, and phenol derivatives such as bisphenol.

  Specific examples of negatively chargeable charge control agents include Spiron Black TRH, T-77, T-95 (Hodogaya Chemical Co., Ltd.), BONTRON (registered trademark) S-34, S-44, S-. 54, E-84, E-88, E-89 (manufactured by Orient Chemical Co., Ltd.).

  The use amount of these charge control agents is preferably 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the binder resin.

[Flowability improver]
A fluidity improver may be added to the toner according to the present invention.

  The fluidity improver can be added to the toner particles to increase the fluidity before and after the addition.

As the fluidity improver, those having a specific surface area by nitrogen adsorption measured by the BET method of preferably 30 m ² / g or more, more preferably 50 m ² / g or more give good results. Further, the addition amount of the fluidity improver is preferably 0.01 to 8 parts by mass, more preferably 0.1 to 4 parts by mass with respect to 100 parts by mass of the toner. is there.

[Other additives]
The toner according to the present invention can be used as a one-component developer by mixing with the fluidity improver and, if necessary, further mixing with another external additive (for example, a charge control agent). Further, it can be used as a two-component developer together with a magnetic carrier. Conventionally known magnetic carriers can be used in the two-component development method. Specifically, particles having an average particle diameter of 20 to 300 μm, such as metal such as surface oxidized or unoxidized iron, nickel, cobalt, manganese, chromium, rare earth, and alloys or oxides thereof, are preferably used.

  Further, those obtained by adhering or coating substances such as styrene resin, acrylic resin, silicone resin, fluorine resin, polyester resin on the surface of the carrier particles are preferably used.

[Developer production method]
In the method for producing a developer according to the present invention, there is no particular limitation except that the developer is produced using a binder resin obtained through the following steps. The binder resin according to the present invention is obtained by polymerizing a polyester resin as a main component in the presence of the wax. After the polymerization, the resin is cooled and solidified, and the solidified product is melted and kneaded into a thin film evaporator in a molten state. It is obtained through a process of introducing and distilling off volatile components.

  For example, when the pulverization method is employed, the toner can be obtained as follows.

  First, the resin, colorant, and other additives obtained through the above steps are sufficiently mixed by a mixer such as a Henschel mixer or a ball mill, and then a heat kneader such as a heating roll, a kneader or an extruder is used. Melt knead. The obtained kneaded product is cooled and solidified, and pulverized and classified to obtain toner particles. Further, if necessary, an external additive is sufficiently mixed with the toner particles by a mixer such as a Henschel mixer to obtain a toner.

  In addition to the wax dispersed in the binder resin when the toner is produced, a wax may be further added. The reason why the wax can be added also during the toner production is that the wax further added during the production of the toner is easily dispersed in the binder resin due to the influence of the wax previously dispersed in the binder resin. It is thought that.

<Developing apparatus and developing method>
Next, an example of the developing device according to the present invention will be specifically described with reference to FIGS. In addition, the developing method according to the present invention will be described.

  FIG. 2 is a schematic view of an example of a developing device according to the present invention.

  In FIG. 2, an electrostatic latent image carrier, for example, a photosensitive drum 601 that carries an electrostatic latent image formed by a known process, rotates in the direction of arrow B. The developing sleeve 608 (developer carrying member) carries a one-component magnetic developer having magnetic toner particles supplied to the developing container 603 and rotates in the direction of arrow A, thereby developing sleeve 608 and photosensitive drum 601. The developer is transported to the developing region D facing each other. As shown in FIG. 2, a magnet (magnet roller) 609 is disposed in a developing sleeve 608 that is rotatably held in order to magnetically attract and hold the developer on the developing sleeve 608. A developing sleeve 608 used in the developing device according to the present invention has a resin layer 607 coated on a metal cylindrical tube 606 as a base. The developing container is divided into a first chamber 614 and a second chamber 615, and the magnetic developer existing in the first chamber 614 passes through a gap formed by the developing container 603 and the partition member 604 by the stirring and conveying member 605. And sent to the second chamber 615. The magnetic developer is carried on the developing sleeve 608 by the action of magnetic force by the magnet roller 609. A stirring member 611 is provided in the second chamber 615 to prevent the developer from staying. The developer obtains a triboelectric charge capable of developing the electrostatic latent image on the photosensitive drum 601 by friction between the magnetic toners and the resin layer 607 on the developing sleeve 608.

  In FIG. 2, an elastic regulating blade having an elastic member is used as the developer layer thickness regulating member 616 that regulates the layer thickness of the developer on the developing sleeve 608. Examples of the elastic regulating blade having an elastic member include those made of an elastic plate made of a material having rubber elasticity such as urethane rubber or silicone rubber, or a material having metal elasticity such as phosphor bronze or stainless steel. The elastic regulating blade 616 may be used in contact with or pressed against the developing sleeve 608 via the toner. In the system having this form, the surface of the toner can be imparted with frictional charge as compared with the prior art. With it, you can get a great effect.

  This is due to the following reason. In a developing device that contacts or presses an elastic regulating blade, a thin layer of developer can be formed on the developing sleeve 608 while the toner coat layer is subjected to strong regulation. Further, by using the toner (developer) and the developing sleeve (developer carrying member) defined in the present invention, the triboelectric charge amount of the toner on the developing sleeve can be kept high and uniform. This is because the development characteristics can be further improved.

  The contact pressure of the elastic regulating blade 616 with respect to the developing sleeve 608 is preferably a linear pressure of 5 g / cm to 50 g / cm (4.9 N / m to 49 N / m). When the contact pressure is within the above range, the regulation of the developer can be stabilized, and the amount of developer carried on the developer carrying member and the amount of triboelectric charge can be optimized. In addition, the restrictions on the developer become weak, and problems such as fogging and developer leakage are less likely to occur. Further, the developer is hardly deteriorated and the developer is hardly fused to the sleeve and the elastic regulation blade.

  Further, as shown in FIG. 3, a magnetic blade disposed away from the developing sleeve may be used as the developer layer thickness regulating member instead of the elastic regulating blade.

  2 and 3 schematically show an example of the developing device according to the present invention. In addition to the layer thickness regulating member described above, there are various forms such as the shape of the developing container 603 (hopper), the presence / absence of the stirring blades 605 and 611, the arrangement of the magnetic poles, the shape of the supply member 612, and the presence / absence of the supply container. Needless to say.

<Measurement method>
Next, a method for measuring physical properties according to the present invention will be described.

(1) Measurement of the arithmetic average roughness (Ra) of the surface of the developer carrier The arithmetic average roughness (Ra) of the surface of the developer carrier is measured based on the surface roughness of JIS-B0601 (2001). A measuring device “SURFCOM 1500DX” (manufactured by Tokyo Seimitsu Co., Ltd.) was used, and the measurement conditions were a cutoff of 0.8 mm, an evaluation length of 8 mm, and a feed rate of 0.6 mm / s. The measurement positions are a total of three positions, the middle position between the developer carrier and the both ends of the coating. Further, after rotating the 90 ° developer carrier, the same three locations, and further 90 ° developer carrier. After the rotation, the measurement was similarly performed at three points, a total of nine points, and the average value was taken.

(2) Measurement of volume resistance value of resin layer of developer carrier The same coating liquid as that for forming a resin layer on the developer carrier is formed on a polyethylene terephthalate (PET) sheet having a thickness of 100 μm. Then, a 20 μm resin layer was formed, and the volume resistance value was measured with a resistivity meter Loresta AP (manufactured by Mitsubishi Chemical Corporation) using a 4-terminal probe. The measurement environment was a temperature of 20 to 25 ° C. and a humidity of 50 to 60% RH.

(3) Measurement of particle size of conductive particles and particles in coating solution Particle size of conductive particles and particles in coating solution is measured by Coulter LS-230 type particle size distribution meter (trade name) , Manufactured by Beckman Coulter, Inc.). As a measuring method, a small amount module is used, and isopropyl alcohol (IPA) is used as a measuring solvent. The measurement system of the particle size distribution analyzer was washed with IPA for 5 minutes, and the background function was executed after washing. Next, 1 mg of a measurement sample is added to 50 ml of IPA. The solution in which the sample was suspended was subjected to a dispersion treatment with an ultrasonic disperser for 1 minute to obtain a sample solution. Then, the sample solution is gradually added to the measurement system of the measurement device, and the measurement is performed by adjusting the sample concentration in the measurement system so that the PIDS on the screen of the device is 45% to 55%. The volume average particle diameter calculated from the above was obtained.

(4) Measurement of glass transition point (Tg) of resin for toner and melting point of wax In the present invention, the glass transition point of the binder resin in which the wax is dispersed (hereinafter also referred to as toner resin) is determined by a differential scanning calorimeter ( DSC measuring apparatus) and Q-1000 (TA Instruments Japan) were used for measurement according to the following conditions. As the glass transition point of the resin for toner, a temperature at which an endothermic peak measured at temperature increase II of the following temperature curve was detected was used.

Sample: 10 mg
Measurement method: A sample was put in an aluminum pan, and an empty aluminum pan was used as a reference.

Temperature curve: Temperature increase I (20 ° C. → 180 ° C., temperature increase rate 10 ° C./min.)
Temperature drop I (180 ° C. → 10 ° C., temperature drop rate 10 ° C./min.)
Temperature increase II (10 ° C. → 180 ° C., temperature increase rate 10 ° C./min.)
Regarding the melting point of the wax, the endothermic peak was measured in the same manner except that the object to be measured was changed from the resin for toner to the wax, and the temperature of the obtained endothermic peak was taken as the melting point of the wax.

(5) Measurement of molecular weight distribution of resin for toner by GPC Stabilize the column in a heat chamber at a temperature of 40 ° C., flow THF at a flow rate of 1 ml / min as a solvent to the column at this temperature, and inject 100 μl of the THF sample solution. And measured. In measuring the molecular weight of the sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithmic value and the count value of a calibration curve prepared from several types of monodisperse polystyrene standard samples. As a standard polystyrene sample for preparing a calibration curve, TSK standard polystyrene (trade name: A-2500) manufactured by Tosoh Corporation was used.

The detector used was an RI (refractive index) detector. As the column, Tosoh Corp. _{TSKgel G1000H (H XL), G2000H} (H XL), G3000H (H XL), G4000H (H XL), G5000H (H XL), G6000H (H XL), G7000H (H _XL ) and TSKgull column (both trade names) were used.

  In addition, the sample solution was adjusted so that the concentration of the component soluble in THF was 0.8% by mass, allowed to stand at a temperature of 25 ° C. for several hours, and then shaken sufficiently to mix well with THF (sample mixing). It was allowed to stand for 12 hours or more until the unity disappeared. At that time, the standing time in THF was set to 24 hours. Thereafter, a sample processed filter (pore size 0.5 μm, for example, Mysori Disc H-25-2 (manufactured by Tosoh Corporation)) can be used as a GPC sample. The sample concentration was adjusted so that the resin would be 5 mg / ml.

(6) Measurement of toner particle size Coulter Multisizer III (trade name, manufactured by Beckman Coulter, Inc.) was used as a measuring device. As the electrolytic solution, first-grade sodium chloride was used and a 1% NaCl aqueous solution was used. As a dispersant, 0.5 ml of alkylbenzene sulfonate was added to 100 ml of the electrolytic aqueous solution, and 10 mg of a measurement sample was further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for 1 minute, and the volume and number distribution of the measurement sample are measured by using the measurement apparatus with a 100 μm aperture as the aperture. Was calculated. From this result, the weight-based weight average particle diameter (D ₄ ) determined from the volume distribution was determined.

  EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited to this at all.

  In the following description, “part” and “%” mean “part by mass” and “% by mass”, respectively, unless otherwise specified.

<Quaternary phosphonium salt>
As the quaternary phosphonium salt used for the resin layer of the developer carrying member, the following quaternary phosphonium salts 1 to 6 were used.

[Quaternary phosphonium salt 1]
In Table 1, Exemplified Compound No. A quaternary phosphonium salt (manufactured by Nippon Chemical Industry Co., Ltd., trade name: Hishicolin BTPPBr) shown as 1 was designated as quaternary phosphonium salt 1.

[Quaternary phosphonium salt 2]
In Table 1, Exemplified Compound No. The quaternary phosphonium salt (produced by Tokyo Chemical Industry Co., Ltd., ethyltriphenylphosphonium bromide) shown as 2 was used as the quaternary phosphonium salt 2.

[Quaternary phosphonium salt 3]
In Table 1, Exemplified Compound No. A quaternary phosphonium salt (manufactured by Junsei Kagaku Co., Ltd .: butyltriphenylphosphonium iodide) shown as 6 was used as the quaternary phosphonium salt 3.

[Quaternary phosphonium salt 4]
In Table 1, Exemplified Compound No. A quaternary phosphonium salt (produced by Alfa Aesar: butyltriphenylphosphonium chloride) shown as 8 was used as the quaternary phosphonium salt 4.

[Quaternary phosphonium salt 5]
In Table 1, Exemplified Compound No. The quaternary phosphonium salt shown as 9 (manufactured by Tokyo Chemical Industry Co., Ltd., tetraethylphosphonium bromide) was used as the quaternary phosphonium salt 5.

[Quaternary phosphonium salt 6]
In Table 1, Exemplified Compound No. The quaternary phosphonium salt (manufactured by Tokyo Chemical Industry Co., Ltd., tetraethylphosphonium chloride) shown as 10 was used as the quaternary phosphonium salt 6.

<Conductive fine particles>
As the conductive fine particles used for the developer carrying member, the following conductive fine particles 1 and 2 were used.

[Conductive fine particles 1]
As a raw material, β-resin was extracted from coal tar pitch by solvent fractionation, hydrogenated and heavyized, and then the solvent-soluble component was removed with toluene to obtain mesophase pitch. The mesophase pitch powder is finely pulverized, oxidized in air at 300 ° C., and then heat-treated at 2800 ° C. in a nitrogen atmosphere to obtain graphite particles having a volume average particle diameter of 3.4 μm through classification. The conductive fine particles 1 were used.

[Conductive fine particles 2]
Conductive carbon black (trade name: Toka Black # 5500, manufactured by Tokai Carbon Co., Ltd.) was used as the conductive fine particles 2.

<Roughness imparting particles>
As the irregularity imparting particles used for the resin layer of the developer carrier, spherical particles (trade name: Nikabead ICB1020 manufactured by Nippon Carbon Co., Ltd.) were used.

<Resin (A)>
As the binder resin (resin (A)) used for the resin layer of the developer carrying member, the following binder resins 1 to 3 were used. The binder resins 1 and 3 have either —NH ₂ group, ═NH group or —NH— bond in the structure, and the binder resin 2 has —NH ₂ group in the structure = It has neither NH group nor —NH— bond.

[Binder resin 1]
A resol type phenolic resin solution (manufactured by DIC Corporation, trade name: J-325) produced using an ammonia catalyst was used as the binder resin 1.

[Binder resin 2]
A resol-type phenol resin solution (manufactured by DIC Corporation, trade name: GF9000) prepared using a NaOH catalyst was used as the binder resin 2.

[Binder resin 3]
A melamine resin solution (manufactured by Sanwa Chemical Co., Ltd., trade name: MW30M) was used as the binder resin 3.

<Wax>
As the wax, a wax having a low melting point and a wax having a high melting point were used. The following wax 1 or 2 was used as the wax having a low melting point. Fischer-Tropsch wax (melting point: 105 ° C.) was used as the wax having a high melting point.

[Wax 1]
A polar wax having a hydroxyl group as a functional group and a melting point of 75 ° C.

[Wax 2]
An ester wax having an ester group as a functional group and a melting point of 70 ° C.

<Binder-containing toner resin>
As the binder resin for the toner containing wax, the following toner resins 1 to 14 were used. Table 2 shows the outline of each binder resin of the toner resins 1 to 14 and the conditions of the thin film evaporator.

[Toner Resin 1]
The following raw materials were mixed to obtain a vinyl monomer / polyester resin mixture.
Unsaturated polyester resin P-1 74.0 parts by mass (Bisphenol A propion oxide: 1.15 mol / terephthalic acid: 0.400 mol / isophthalic acid: 0.588 mol / fumaric acid: 0.0120 mol) Tg = 60 ° C., peak molecular weight = 7700, number average molecular weight = 4600)
・ Vinyl monomer ・ Styrene 18.0 parts by mass ・ Butyl acrylate 6.0 parts by mass ・ Monobutyl maleate 2.0 parts by mass ・ Polymerization initiator 0.08 parts by mass (2,5-dimethyl-2,5-bis (T-Butylperoxy) hexyne (10 hour half-life temperature 128.4 ° C.))
-Wax a (wax 1) 3.0 parts by mass-Wax b (Fischer-Tropsch wax (melting point 105 ° C)) 2.0 parts by mass After polymerizing this vinyl monomer / polyester resin mixture at 120 ° C for 10 hours, The temperature was raised to 150 ° C. and held for 4 hours to polymerize the unreacted vinyl monomer. Thereafter, the temperature was further raised to 180 ° C., and the pressure was reduced for 5 hours to carry out a crosslinking reaction and alcohol removal, whereby a hybrid resin I was obtained.

The obtained hybrid resin I is cooled and solidified, and then pulverized to obtain a solidified product. The obtained solidified product was melt-kneaded, and this resin was introduced into a thin film evaporator (EXEVA EX-02 type) in a molten state for treatment. The processing conditions using the thin film evaporator were as follows: resin thickness: 3 mm, jacket temperature setting: 180 ° C., stirring rotation speed: 250 rpm, and vacuum degree: 1 Torr. The feed amount was 50 kg / m ² h.

  After the treatment by the thin film evaporator, the resin was taken out from the thin film evaporator and pulverized to obtain a toner resin 1.

[Toner Resin 2]
In the production example of the toner resin 1, as shown in Table 2, a toner resin 3 was obtained in the same manner as in the production example of the toner resin 1 except that the wax 1 was changed to the wax 2.

[Toner Resin 3]
In the production example of the toner resin 1, as shown in Table 2, the toner resin 3 was obtained in the same manner as in the production example of the toner resin 1 except that the amount of the wax 1 was changed.

[Toner Resin 4]
In the production example of the toner resin 1, as shown in Table 2, a toner resin 4 was obtained in the same manner as in the production example of the toner resin 1 except that the wax b was not added.

[Toner Resin 5]
-Bisphenol A propylene oxide 2-mole adduct 40.0 parts by mass-Bisphenol A propylene oxide 3-mole adduct 26.0 parts by mass-Terephthalic acid 12.0 parts by mass-Isophthalic acid 12.0 parts by mass-Tetrabutyl titanate 0. 2 parts by mass The above materials were placed in a polymerization kettle and reacted at 220 ° C. for 10 hours while distilling off the water produced under a nitrogen stream. Next, 10.0 parts by weight of trimellitic anhydride, 3.0 parts by weight of wax 1 and 2.0 parts by weight of Fischer-Tropsch wax (melting point 105 ° C.) were added, and the reaction was performed for 2 hours under normal pressure sealing to obtain Resin II. It was.

  After cooling and solidifying the obtained resin II, the solidified product was melted and kneaded, and further this resin was introduced into a thin film evaporator (EXEVA EX-02 type) in a molten state for treatment. It was. The conditions for the treatment by the thin film evaporator were the same as those for the resin 1 for toner.

  After the treatment by the thin film evaporator, the resin was taken out from the thin film evaporator and pulverized to obtain a toner resin 5.

[Toner Resin 6]
In the production example of the toner resin 5, as shown in Table 2, a toner resin 6 was obtained in the same manner as in the production example of the toner resin 5 except that the wax 1 was changed to the wax 2.

[Toner Resin 7]
In the production example of the toner resin 1, as shown in Table 2, the toner resin 1 was prepared in the same manner as in the production example of the toner resin 1 except that the addition amounts of the unsaturated polyester P-1 and the vinyl monomer were changed. Resin 7 was obtained.

[Toner Resin 8]
In the production example of the toner resin 1, as shown in Table 2, a toner resin 8 was obtained in the same manner as in the production example of the toner resin 1 except that no wax was added.

[Toner Resin 9]
In the production example of the resin 1 for toner, the production example of the resin 1 for toner is performed except that the hybrid resin I is melted and kneaded without being cooled and solidified and introduced into a thin film evaporator (EXEVA EX-02 type) in a molten state. In the same manner as above, a toner resin 9 was obtained.

[Toner Resin 10]
In the production example of the resin 1 for toner, the solidified product obtained by pulverizing the hybrid resin I after cooling and solidification was introduced into a thin film evaporator (EXEVA EX-02 type) without melting and kneading. In the same manner as in the resin 1 production example, a toner resin 10 was obtained.

[Toner Resin 11]
Production example of toner resin 1 in the production example of resin 1 for toner, except that the solidified product obtained by pulverizing hybrid resin I after cooling and solidification was melt-kneaded and then not introduced into a thin film evaporator. In the same manner as above, a toner resin 11 was obtained.

[Toner Resin 12]
-Styrene 70.0 parts by mass-N-butyl acrylate 24.0 parts by mass-Monobutyl maleate 6.0 parts by mass-Di-t-butyl peroxide 1.0 part by mass-Wax a (Wax 1) 3.0 Part by mass / wax b (Fischer-Tropsch wax (melting point: 105 ° C.)) 2.0 part by mass The above material was dropped into 200.0 parts by mass of xylene over 4 hours and polymerized under reflux of xylene to obtain Resin III. It was.

  After the obtained resin III was cooled and solidified and pulverized, the solidified product was melted and kneaded, and this resin was introduced into a thin film evaporator (EXEVA EX-02 type) in a molten state. The conditions of the thin film evaporator were the same as those for the toner resin 1.

  After the treatment by the thin film evaporator, the resin was taken out from the thin film evaporator and pulverized to obtain a toner resin 12.

[Toner Resin 13]
In the production example of the resin 1 for toner, the same procedure as in the production example of the resin 1 for toner was performed except that the hybrid resin I was polymerized and then pulverized without being cooled and solidified and melt-kneaded and not introduced into the thin film evaporator. A toner resin 13 was obtained.

[Toner Resin 14]
In the production example of the resin 5 for toner, in the same manner as in the production example of the resin 5 for toner, except that the resin II is polymerized, not cooled and solidified and melt-kneaded, and not pulverized without being introduced into the thin film evaporator. Toner resin 14 was obtained.

<Paint for forming resin layer of developer carrier>
(Preparation of paint 1)
Methanol was added to the following materials to adjust the solid content to 40%, and this was dispersed for 2 hours in a sand mill (using glass beads having a diameter of 1 mm as media particles).
-Binder resin 1 100 parts by mass-Conductive fine particles 1 60 parts by mass-Conductive fine particles 2 6 parts by mass-Quaternary phosphonium salt 1 10 parts by mass-Convex / concave imparting particles 30 parts by mass The glass beads were separated using a sieve. Then, methanol was added so that the solid content concentration was 30% to obtain a paint 1.

(Preparation of paint 2-16)
As shown in Table 3, the coating material 2 was changed in the same manner as in Table 3, except that the type and addition amount of the binder resin, and the addition amount of the conductive fine particles, the quaternary phosphonium salt, and the unevenness imparting particles were changed. ~ 16 were obtained respectively.

(Preparation of paint 17)
As shown in Table 3, the same as paint 1 except that the quaternary phosphonium salt used in paint 1 was changed to a quaternary ammonium salt (trade name: A-902, manufactured by Carrinet). Thus, paint 17 was obtained.

<Developer carrier>
(Preparation of developer carrier 1)
As a substrate, a cylindrical aluminum tube having an outer diameter of 20.0 mmφ and an arithmetic average roughness (Ra) of 0.2 μm with masking on the upper and lower ends was prepared. The substrate was erected vertically and rotated at a constant speed, and the paint 1 was applied while lowering the spray gun at a constant speed. Subsequently, the coating layer was dried and cured by heating at 190 ° C. for 30 minutes in a hot air drying oven to form a resin layer on the substrate, thereby producing a developer carrier 1. The volume resistance and arithmetic average roughness Ra of the developer carrier 1 were measured and found to be 0.52 Ω · cm and 1.35 μm, respectively. Table 3 shows the configuration and physical properties of the resin layer of the developer carrier 1.

(Preparation of developer carriers 2 to 17)
In the developer carrier 1, developer carriers 2 to 17 were prepared in the same manner as the developer carrier 1 except that the type of paint was changed as shown in Table 3. Table 3 shows the constitution and physical properties of the resin layer of each developer carrier.

<Toner>
(Manufacture of toner 1)
-Toner resin 1 100 parts by mass-Magnetic substance (average particle size 0.2 [mu] m) 95 parts by mass-Charge control agent (product name: T-77, manufactured by Hodogaya Chemical Co., Ltd.) 2 parts by mass The above raw materials were set at 450 rpm After premixing for 3 minutes with a Henschel mixer, the set temperature was adjusted so that the direct temperature near the outlet of the kneaded product was 150 ° C. or more and 160 ° C. or less by a biaxial kneading extruder set at 130 rpm, and melt kneading. The obtained kneaded product is cooled and coarsely pulverized by a cutter mill, and then the obtained coarsely pulverized product is finely pulverized using a turbo mill (manufactured by Turbo Kogyo Co., Ltd.) and a multi-division classifier using the Coanda effect is used. Then, toner particles 1 were obtained.

1.3 parts by mass of hydrophobic silica fine particles (BET 200 m ² / g silica fine particles produced by vapor phase oxidation of silicon halogen compound surface-treated with hexamethyldisilazane) with respect to 100 parts by mass of toner particles 1 Then, 0.6 part by mass of strontium titanate having a number average primary particle size of 0.9 μm was externally added and mixed with a Henschel mixer to obtain toner 1. Table 4 shows the configuration and physical properties of Toner 1.

  The wax shown in Table 4 was added at the time of toner production and is not already contained in the toner resin.

(Production of toners 2 to 14)
As shown in Table 4, in the toner 1, the toners 2 to 14 were prepared in the same manner as the toner 1 except that the type of toner resin, the type of wax added at the time of toner production, and the amount added were changed. Was made. Table 4 shows the formulation and physical properties of each toner.

(Preparation of Toner 15)
-Resin for toner 6 100.0 parts by mass-Fischer-Tropsch wax (melting point 105 ° C) 5.0 parts by mass-Charge control agent (aluminum 3,5-di-t-butylsalicylate compound) 0.5 parts by mass I. Pigment Blue 15: 3 8.0 parts by mass The above formulation was mixed with a Henschel mixer (FM-75 type, manufactured by Mitsui Miike Chemical Co., Ltd.), and then a twin-screw kneader (PCM-30 type, Kneaded by Ikekai Tekko Co., Ltd. The obtained kneaded material was cooled and coarsely pulverized to 1 mm or less with a hammer mill to obtain a coarsely pulverized material. The obtained coarsely crushed material was finely pulverized with a mechanical pulverizer (T-250, manufactured by Turbo Kogyo Co., Ltd.). Further, the obtained finely pulverized product is classified, and further subjected to spheroidization treatment 5 times using a hybridizer (manufactured by Nara Machinery Co., Ltd.) to obtain toner particles 15 having a weight average particle diameter (D4) of 5.8 μm. It was.

  Toner particles 15: 100.0 parts by mass, titanium oxide fine particles: 0.2 parts by mass (primary average particle diameter of 50 nm surface-treated with 15% by mass of isobutyltrimethoxysilane), silica fine particles: 0.8 parts by mass (hexamethyl) A primary average particle diameter of 16 nm surface-treated with 20% by mass of disilazane) and 1: 0.5 parts by mass of inorganic fine particles were mixed with a Henschel mixer (FM-75 type, manufactured by Mitsui Miike Chemical Co., Ltd.) to obtain a toner. 15 was obtained. Table 4 shows the configuration and physical properties of the toner 15.

<Magnetic carrier>
(Production of magnetic carrier)
The following mixture is added to 100 parts by mass of Mn-Mg-ferrite particles having a 50% volume-based particle size (D50) of 33 μm, and further dried under reduced pressure at 70 ° C. for 5 hours while stirring and mixing with a solution vacuum kneader. And the solvent was removed.
・ Silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd .: KR271) 1 part by mass ・ 0.5 part by mass of γ-aminopropyltriethoxysilane ・ 98.5 parts by mass of toluene Thereafter, baking is performed at 140 ° C. for 2 hours, and a sieve shaker (300MM-2 type, Tsutsui RIKEN MACHINERY Co., Ltd .: 75 μm opening), a magnetic carrier having a D50 of 38 μm was obtained.

Example 1
The developer carrier and toner provided in the Canon copier iR2000 were replaced with developer carrier 1 and toner 1, respectively, the distance between the developer carrier and the photoconductor was 290 μm, and the following evaluation was performed. It was.

<1> Image Quality As an initial (first image) image quality evaluation, a test chart of a line image (line width 190 μm) is copied at an image ratio of 5.5% under a high temperature and high humidity environment (30 ° C., 80% RH). The printed matter obtained by this was used. Then, the printed matter was measured by personal IAS (manufactured by Quality Engineering Associates) to obtain a scattering index (a numerical value representing how lines are blurred as defined by ISO 13660). The image quality was evaluated by the obtained scattering index.

  Thereafter, 150,000 copies were made in a two-sheet intermittent mode using a text chart with a printing ratio of 6% under the same high temperature and high humidity environment as the initial stage. Then, after printing 150,000 sheets, a printed matter was obtained using the same test chart as in the initial stage (first sheet), and the image quality after printing 150,000 sheets was evaluated in the same manner as in the initial stage. Table 5 shows the evaluation results obtained at the initial stage and after printing 150,000 sheets.

The evaluation criteria for image quality evaluation are as follows.
Rank A: Spattering index less than 23 Rank B: Scattering index from 23 to less than 26 Rank C: Scattering index from 26 to less than 29 Rank D: Scattering index from 29 to less than 32 Rank E: Scatter index from 32 to 35 Rank F: Scattering index from 35

<2> Image Density As an initial (first sheet) image density evaluation, copy a test chart of a solid circle image with a diameter of 5 mm and an image ratio of 5.5% in a normal temperature and low humidity environment (23 ° C., 5% RH). The printed matter obtained by the above was used. Then, the image density of a solid circle part having a diameter of 5 mm on the printed matter was measured with a reflection densitometer “RD918” (trade name, manufactured by Macbeth), and the average value of the 10 points was evaluated as the image density.

  Thereafter, 150,000 copies were made in a two-sheet intermittent mode using a text chart with a printing ratio of 6% under the same room temperature and low humidity environment as the initial stage. Then, after printing 150,000 sheets, a printed matter was obtained using the same test chart as in the initial stage (first sheet), and the image density after printing 150,000 sheets was evaluated in the same manner as in the initial stage. Table 5 shows the evaluation results obtained at the initial stage and after printing 150,000 sheets.

  It was judged that the higher the image density, the better the image.

The evaluation criteria for image density evaluation are as follows.
Rank A: Image density 1.40 or more Rank B: Image density 1.35 or more and less than 1.40 Rank C: Image density 1.30 or more and less than 1.35 Rank D: Image density 1.25 or more and less than 1.30 Rank E : Image density of 1.20 or more and less than 1.25 Rank F: Image density of less than 1.20

<3> Fog The reflectance of the solid white area on the printed material after the initial (first sheet) and after 150,000 sheets obtained in the evaluation of the image density in <2> above was randomly measured at 10 points, and the lowest value was not determined. The fog density was obtained by subtracting the reflectance (average value at 10 locations) of the transfer paper used. This value was evaluated according to the following criteria. The reflectance was measured by a reflectance meter “TC-6DS” (trade name, manufactured by Tokyo Denshoku Co., Ltd.). The obtained evaluation results are shown in Table 5.
Rank A: fog density less than 0.5 Rank B: fog density from 0.5 to less than 1.0 Rank C: fog density from 1.0 to less than 1.5 Rank D: fog density from 1.5 to less than 2.0 Rank E : Fog density of 2.0 or more and less than 3.0 rank F: fog density of 3.0 or more

(Examples 2 to 16 and Comparative Examples 1 to 8)
The combinations of developer carrier and toner used for evaluation were changed as shown in Table 5, and in the same manner as in Example 1, Examples 2 to 16 and Comparative Examples 1 to 8 were evaluated. The test results are shown in Table 5.

(Examples 17 to 19 and Comparative Example 8)
The electrophotographic apparatus used for the evaluation was changed from the Canon copying machine iR2000 used in Example 1 to the Canon copying machine iR1750. Furthermore, the number of printed sheets was changed from 150,000 to 1 million. Evaluations of Examples 17 to 19 and Comparative Example 8 were performed in the same manner as the evaluation performed in Example 1 except that the electrophotographic apparatus and the number of printed sheets were changed as described above. The evaluation results are shown in Table 6.

(Example 20)
In Example 1, the electrophotographic apparatus used for the evaluation was changed from the Canon copying machine iR2000 to the Canon multifunction machine iRC4580, and the number of printed sheets was changed from 150,000 to 1,000,000. Similar to the evaluation, evaluation of Example 20 was performed. At this time, a two-component developer in which 92 parts by mass of magnetic carrier and 8 parts by mass of toner 15 were mixed by a V-type mixer was used. The evaluation results are shown in Table 6.

  In Comparative Example 1, the image density and image quality after 150,000 sheets in a high temperature and high humidity environment and a normal temperature and low humidity environment were D ranks. This is presumably because the toner contains a binder resin whose main component is not a polyester resin.

  In Comparative Example 2, the image density and image quality after 150,000 sheets in a high temperature and high humidity environment and a normal temperature and low humidity environment were D rank. This is presumably because the toner contains a binder resin obtained by polymerization in the absence of wax.

  In Comparative Example 3, the image density and image quality after 150,000 sheets in a high temperature and high humidity environment and a normal temperature and low humidity environment were D rank. This is presumably because the toner contains a binder resin that has not undergone a cooling and solidification step after polymerization.

  In Comparative Example 4, the image density and image quality after 150,000 sheets in a high temperature and high humidity environment and a normal temperature and low humidity environment were D rank. This is presumably because the toner contains a binder resin that has not undergone a kneading step after polymerization.

  In Comparative Example 5, the image density and image quality after 150,000 sheets in a high temperature and high humidity environment and a normal temperature and low humidity environment were D rank. This is presumably because the toner contains a binder resin that does not use a thin film distiller after polymerization.

  In Comparative Example 6, the image density and image quality after 150,000 sheets in a high temperature and high humidity environment and a normal temperature and low humidity environment were D rank. This is presumably because the quaternary phosphonium salt was not contained in the resin layer of the developer carrying member.

In Comparative Example 7, the image quality, image density and fogging after 150,000 sheets in a high temperature and high humidity environment and a normal temperature and low humidity environment were D ranks. This is presumably because the resin layer of the developer carrying member contains a resin having no structure of —NH ₂ group, ═NH group and —NH— bond.

In Comparative Example 8, the image density and image quality after 150,000 sheets in a high temperature and high humidity environment and a normal temperature and low humidity environment were D rank. This is considered to be because the toner contains a binder resin whose main component is not a polyester resin. In Comparative Example 9, the image density and image quality after 150,000 sheets in a high temperature and high humidity environment and a normal temperature and low humidity environment are D ranks. there were. This is presumably because a resin that does not go through a cooling and kneading step after polymerization and does not use a thin film distiller was used for the toner.

  In Comparative Example 10, the image density and image quality after 1 million sheets in a high temperature and high humidity environment and a normal temperature and low humidity environment were D rank. This is presumably because a resin that does not go through a cooling and kneading step after polymerization and does not use a thin film distiller was used for the toner.

Claims (9)

Developer,
A developer container for containing the developer;
A developer carrying member for carrying and transporting the developer on the surface;
A developer layer thickness regulating member for regulating the amount of developer on the developer carrying member;
A developing device comprising:
The developer carrier has a base and a resin layer formed on the surface of the base,
The resin layer is
A resin (A) having at least one structure selected from the group consisting of —NH ₂ group, ═NH group and —NH— bond in the structure;
A quaternary phosphonium salt having a structure represented by the following formula (1), and
It is formed using a resin composition containing conductive fine particles,
The developer is a toner containing a binder resin, a colorant and a wax,
The binder resin is a polyester-based resin as a main component, polymerized in the presence of the wax, cooled and solidified after polymerization, melted and kneaded the solidified product, introduced into a thin film evaporator in a molten state, A developing device obtained through a step of distilling off volatile components.

(In the formula (1), R ₁ to R ₃ are each independently an optionally substituted alkyl group having 1 to 4 carbon atoms, which may have a substituent phenyl group and a substituted group R ₄ is an optionally substituted benzyl group, and R ₄ has an optionally substituted alkyl group having 1 to 16 carbon atoms, an optionally substituted alkenyl group, and a substituent. Or an optionally substituted alkynyl group, an optionally substituted phenyl group or an optionally substituted benzyl group, and X ⁻ is a halogen ion, OH ⁻ , an organic acid ion or an inorganic acid ion. An anion selected from Among R _{1 to} R ₄ of the quaternary phosphonium salt having the structure represented by the formula (1), at least three functional groups may have a butyl group or a substituent which may have a substituent. The developing device according to claim 1, wherein the developing device is a good phenyl group or a benzyl group which may have a substituent. The developing device according to claim 1, wherein the structure of the cation part of the quaternary phosphonium salt having the structure represented by the formula (1) is a structure represented by the following formula (2).
4. The developing device according to claim 1, wherein X ⁻ of the quaternary phosphonium salt having the structure represented by the formula (1) is a bromine ion. 5.   The resin layer contains 1 part by mass or more and 60 parts by mass or less of a quaternary phosphonium salt having a structure represented by the formula (1) with respect to 100 parts by mass of the resin (A). The developing device according to any one of 1 to 4.   The developing device according to claim 1, wherein the resin (A) is a phenol resin.   The developing device according to claim 1, wherein the wax has at least one functional group selected from an ester group, a carboxyl group, and a hydroxyl group.   The developing device according to claim 1, wherein the developer layer thickness regulating member is an elastic regulating blade.   Using the developing device according to any one of claims 1 to 8, the developer is transported to a developing region facing the electrostatic latent image carrier, and the electrostatic latent image is carried by the transported developer. A developing method comprising developing an electrostatic latent image carried on a body.