JP2016114849A - Developer carrier, manufacturing method therefor, and developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developer carrying member capable of maintaining high image quality over a long period of time even when a high frictional charging developer is used, and a method for producing the same. A developer carrier having a substrate and a surface layer, the surface layer comprising: i) a molecular structure comprising a group consisting of —NH 2 group, ═NH group and —NH— bond. A cured product of a resin composition comprising a resin having at least one selected structure, ii) a quaternary phosphonium salt or a quaternary ammonium salt, iii) a metal compound of an aromatic oxycarboxylic acid, and iv) conductive particles. A developer carrier characterized by comprising: [Selection figure] None

Description

  The present invention relates to a developer carrier used in an image forming apparatus such as a copying machine and a printer using electrophotography, a method for producing the developer carrier, and a developing device using the developer carrier. .

  In recent years, the particle size of a developer has been reduced in order to improve the image quality of an electrophotographic image. The smaller the developer particle size, the greater the surface area per unit mass. Therefore, the surface charge of the developer tends to be high during the development process. Further, in order to keep the consumption of the developer low, a developer having an increased average circularity is used. However, a developer having a high average circularity is liable to be excessively charged because the area in contact with the developer carrier increases due to the smoothing of the surface.

  The excessively charged developer has a strong adhesion to the surface of the developer carrying member, so that a part of the surface of the developer carrying member is covered with the overcharged developer. In the portion covered with the excessively charged developer, the developer becomes difficult to come into contact with the developer carrying member, so that the developer is not sufficiently charged. For this reason, an excessively charged developer and a developer that is not sufficiently charged exist on the developer carrying member, so that the charge amount distribution of the developer tends to be wide.

  As a result, image defects such as sleeve ghosts and blotches are likely to occur, and image quality is likely to deteriorate. The sleeve ghost is a phenomenon in which the shape of the toner image formed on the first round of the developing sleeve (developer carrying member) appears on the second round of the developing sleeve when the image is formed. Blotch is a phenomenon in which an image on a spot or a wave pattern image due to poor charging of the developer appears.

  In order to suppress excessive charging of the developer, for example, Patent Document 1 proposes a developer carrier having a resin coating layer containing a specific quaternary ammonium salt and a specific phenol resin.

  Patent Document 2 proposes a developer carrier having a conductive resin coating layer formed using a resin composition containing a specific quaternary phosphonium salt and a specific resin.

Japanese Patent Laid-Open No. 2002-040797 JP 2010-055072 A

  The inventors of the present invention have confirmed that the developer-carrying members described in Patent Documents 1 and 2 are capable of suppressing excessive charging of the developer and providing stable charging.

  However, it has been recognized that there is still room for improvement with respect to controlling the charging property of a developer when a developer that tends to be excessively charged is used for a long period of time.

  Accordingly, an object of the present invention is to provide a developer carrying member that can be stabilized in an appropriate range while suppressing tribocharging of the developer over a long period of time even if the developer is easily charged, and a method for producing the same. Is to provide.

  Another object of the present invention is to provide a developing device capable of stably obtaining high-quality electrophotographic images over a long period of time.

According to the present invention, the substrate has a surface layer, and the surface layer is
i) Resin having at least one structure selected from the group consisting of —NH ₂ group, ═NH group and —NH— bond in the molecular structure ii) Quaternary phosphonium salt or quaternary ammonium salt iii) Aromatic Provided is a developer carrier characterized in that it is a cured product of a resin composition comprising a metal compound of oxycarboxylic acid iv) conductive particles.

  Further, according to the present invention, a negatively chargeable developer, a developer container containing the negatively chargeable developer, and a rotation for carrying and transporting the negatively chargeable developer supplied from the developer container on the surface. A developer apparatus comprising at least a developer carrier that is freely held, and a developer layer thickness regulating member that regulates the layer thickness of the negatively chargeable developer layer formed on the developer carrier. Is provided.

Furthermore, according to the present invention, there is provided a method for producing a developer carrier having a substrate and a surface layer, wherein (I) a surface of the substrate, i) a molecular structure, -NH ₂ group, = NH group And a resin having at least one structure selected from the group consisting of —NH— bonds, ii) quaternary phosphonium salts or quaternary ammonium salts, iii) metal compounds of aromatic oxycarboxylic acids, and iv) conductivity Applying a paint containing a resin composition containing particles to form a coating film having the resin composition on the surface of the substrate; and (II) forming the surface layer by curing the coating film. , A method for producing a developer bearing member is provided.

  According to the present invention, there is provided a developer carrier and a method for manufacturing the same that can stabilize the developer within an appropriate range while suppressing frictional charging of the developer over a long period even if the developer is easily charged. Is possible. It is also possible to provide a developing device that can stably obtain high-quality electrophotographic images over a long period of time.

It is a schematic diagram showing an example of a magnetic one-component developing device using a developer carrying member according to the present invention. It is a schematic diagram which shows another example of the magnetic one-component developing apparatus using the developing agent carrier which concerns on this invention. FIG. 2 is a schematic diagram illustrating an example of a non-magnetic two-component developing device using a developer carrier according to the present invention.

<< Developer carrier >>
The developer carrying member according to the present invention has a base and a surface layer. In addition, for example, an intermediate layer (for example, an elastic layer) may be provided between the base and the surface layer. The developer carrier according to the present invention can be used as a developer carrier for an electrophotographic apparatus. The developer carrier according to the present invention will be described in detail below.

<Substrate>
As the substrate, a substrate known in the field of the developer carrying member can be used, and the shape can be appropriately selected from shapes such as a hollow cylindrical shape, a solid cylindrical shape, and a belt shape. As this substrate, for example, a non-magnetic metal such as aluminum, stainless steel, and brass, or an alloy thereof, formed into a hollow cylindrical shape or a solid cylindrical shape, and polished and ground may be used. it can.

<Surface layer>
The surface layer is a cured product of a resin composition containing i) a binder resin, ii) a quaternary phosphonium salt or a quaternary ammonium salt, iii) a metal compound of an aromatic oxycarboxylic acid, and iv) a conductive particle. The binder resin is a resin having at least one structure selected from the group consisting of —NH ₂ group, ═NH group and —NH— bond in the molecular structure. Moreover, the said resin composition may further contain other additives, such as an uneven | corrugated particle | grains mentioned later.

  When the developer carrying member according to the present invention has such a surface layer, when a negatively chargeable developer is used, an excessive triboelectric charge imparting property to the developer can be suppressed, and a more appropriate triboelectric charge can be obtained. Can be stably provided. As a result, even when a developer that is easily charged is used, it is possible to adjust the triboelectric charge amount to an appropriate range over a long period of time, so that good development characteristics can be obtained. Further, since the developer carrying member according to the present invention has the surface layer having this configuration, the charge amount distribution of the developer can be narrowed, so that a high-quality electrophotographic image can be provided.

  In addition, when neither a quaternary phosphonium salt nor a quaternary ammonium salt is used, the developer carrier having a surface layer formed using a resin composition having the same composition as described above is charged. The effect of suppressing overcharging of the developer, which is easy, was low.

  On the other hand, when a developer carrier having a surface layer formed using a resin composition having the same composition as described above is used, in addition to not using a metal compound of an aromatic oxycarboxylic acid, the developer is easily overcharged. The effect which suppresses to some extent was seen. However, when the addition amount of the quaternary ammonium salt or quaternary phosphonium salt is further increased in order to suppress the excessive charging of the developer, the volume resistance of the surface layer of the developer carrier increases, thereby causing the sleeve ghost. May occur easily. This is because it becomes difficult to overcharge the developer by adding a large amount of quaternary ammonium salt or quaternary phosphonium salt. However, once the developer becomes overcharged, the charge amount on the surface of the developer carrier decreases. It becomes difficult to do. Then, it is considered that the developer that has been overcharged due to long-term use is gradually accumulated on the surface of the developer carrying member, so that sleeve ghosts and image quality are liable to occur. Further, since the wear resistance of the surface layer may be reduced by increasing the amount of quaternary ammonium salt or quaternary phosphonium salt added, further improvement has been demanded.

  On the other hand, the developer carrier having the surface layer according to the present invention uses only one of the above-mentioned aromatic oxycarboxylic acid metal compound, quaternary ammonium salt and quaternary phosphonium salt. Compared to the above, a much greater effect of suppressing excessive charging was obtained. Further, the developer carrying member according to the present invention was able to further stabilize the triboelectric charge amount of the developer.

  The following tests examined the mechanism of suppression of excessive charging of a developer that is manifested by combining these materials.

  First, a surface layer was prepared using the materials i), iii), and iv) without using any of the quaternary phosphonium salt and the quaternary ammonium salt. Then, the surface layer was immersed in an organic solvent such as chloroform in which the aromatic oxycarboxylic acid metal compound is soluble to extract components derived from the aromatic oxycarboxylic acid metal compound. As a result, the elution amount of the component derived from the aromatic oxycarboxylic acid metal compound was very small relative to the amount of the aromatic oxycarboxylic acid metal compound added.

  From this result, it was speculated that the aromatic oxycarboxylic acid metal compound was incorporated into the cured binder resin as part of the polymer as the binder resin was cured.

  Subsequently, a surface layer was produced using the materials i) to iv). And the surface layer was similarly immersed in the said organic solvent, and the component derived from the metal compound of aromatic oxycarboxylic acid was extracted. As a result, compared to the case where no quaternary phosphonium salt or quaternary ammonium salt is added to the resin composition, the component derived from the metal compound of the aromatic oxycarboxylic acid is eluted about 2-3 times more. did.

  From this result, the present inventors speculated that the following phenomenon occurred.

  Both the aromatic oxycarboxylic acid metal compound and the quaternary phosphonium or quaternary ammonium salt are incorporated as part of the polymer as the binder resin cures. However, a quaternary phosphonium salt or a quaternary ammonium salt binds preferentially to a binder resin having a specific structure rather than a metal compound of an aromatic oxycarboxylic acid. Therefore, the presence of a large amount of aromatic oxycarboxylic acid that did not bind to the binder resin is considered to increase the elution amount of components derived from the metal compound of aromatic oxycarboxylic acid in the above test.

  The reason why the quaternary phosphonium salt or the quaternary ammonium salt preferentially binds to the binder resin over the metal compound of the aromatic oxycarboxylic acid is not known in detail. However, it is considered that the metal compound of the aromatic oxycarboxylic acid tends to exist in a state where it is not restrained by the binder resin due to the difference in ease of binding with the binder resin. As a result, a large amount of the metal compound of aromatic oxycarboxylic acid having negative chargeability is present in the surface layer in a state where it is not constrained by the binder resin. Thereby, it is considered that excessive charging of the negatively chargeable developer is greatly suppressed without adding a large amount of quaternary phosphonium salt or quaternary ammonium salt. It is presumed that image defects such as sleeve ghosts and blotches can be suppressed.

<Resin composition for surface layer formation>
The resin composition used for forming the surface layer includes the following i) to iv).

i) a resin having at least one structure selected from the group consisting of —NH ₂ group, ═NH group and —NH— bond in the molecular structure;
ii) quaternary phosphonium salts or quaternary ammonium salts,
iii) a metal compound of an aromatic oxycarboxylic acid, and
iv) Conductive particles These i) to iv) contained in the resin composition will be described below.

Resin having at least one structure selected from the group consisting of —NH ₂ group, ═NH group, —NH— bond in the molecular structure The binder resin according to the present invention has a —NH ₂ group in the molecular structure, = Having at least one structure selected from the group consisting of NH group and -NH- bond (hereinafter also referred to as NHn structure). By having the NHn structure in the molecular structure, it is possible to suppress the occurrence of blotches and sleeve ghosts that are thought to be caused by excessive tribocharging of the developer.

  Specific examples of this resin include the following.

  Resins having an NHn structure other than the main chain such as a polyurethane resin, a polyamide resin, a melamine resin, a guanamine resin, a phenol resin having an NHn structure, and a urethane-modified epoxy resin.

  Among these, in particular, the phenolic resin having the above-mentioned NHn structure has high hardness after thermosetting, excellent durability, and the paint used when forming the surface layer has a relatively low viscosity, so that it can be coated. Since it is excellent, it is preferably used. Furthermore, among these, in the production process, a phenol resin produced using a nitrogen-containing compound such as ammonia as a catalyst is more preferable.

  The nitrogen-containing compound is directly involved in the polymerization reaction and is present 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 produced, and even after the reaction is completed, the structure is represented by the following formula (3). Present in phenolic resin.

(3)

  The nitrogen-containing compound used for the production of the phenol resin may be either an acidic catalyst or a basic catalyst.

  The content of the binder resin in the resin composition (resin composition for forming the surface layer) used for forming the surface layer is 50% by mass or more based on the resin composition from the viewpoint of holding the conductive particles in the resin layer. It is preferable that Furthermore, the content of the binder resin in the resin composition is more preferably 80% by mass or less based on the resin composition from the viewpoint of suppressing the resistance of the resin layer. Further, the structure of the binder resin can be analyzed by analyzing with an analyzer such as IR (infrared absorption spectroscopy) or NMR (nuclear magnetic resonance spectroscopy).

-Quaternary phosphonium salt, quaternary ammonium salt In the present invention, a quaternary phosphonium salt or a quaternary ammonium salt is contained in the resin composition in combination with the metal compound of the aromatic oxycarboxylic acid. Is necessary to improve the good triboelectric chargeability to the developer.

(Quaternary phosphonium salt)
The quaternary phosphonium salt will be described below.

  The quaternary phosphonium salt preferably has a structure represented by the following formula (1) from the viewpoint of suppressing excessive charging.

(1)

(In formula (1), Z _{1 to} Z ₄ are each independently an alkyl group having 1 to 18 carbon atoms which may have a substituent, a phenyl group which may have a substituent, or a substituent. have a representative of a naphthyl group or an optionally substituted benzyl group, .Q ^- is a halogen ion, OH ^- it represents an or an organic acid ion).

Further, at least three functional groups of Z _{1 to} Z ₄ are a phenyl group which may have a substituent, a naphthyl group which may have a substituent, and a benzyl group which may have a substituent. Either is preferable. When at least three functional groups of Z _{1 to} Z ₄ are the above functional groups, the dispersion uniformity of the quaternary phosphonium salt with respect to the binder resin (for example, a phenol resin having an NHn structure) can be improved. . Examples of the substituent that each of the phenyl group, naphthyl group, and benzyl group may have independently include a halogen group, a nitro group, a sulfo group, and an alkyl group having 1 to 18 carbon atoms.

Q ^- The organic acid ion, an organic sulfate ion, organic sulfonate ion, organic phosphate ion, molybdate ion, tungstate ion, and include heteropolyacid ions containing molybdenum atoms or tungsten atoms.

Further, Q ⁻ is more preferably a halogen ion or OH ⁻ from the viewpoint that excessive charging can be further suppressed as a developer carrying member.

  Specific examples of the quaternary phosphonium salt are shown in the following Table 1, but of course, the present invention is not limited thereto. In Table 1 below, “Ph” represents a phenyl group.

The quaternary phosphonium salt is generally used as a positively chargeable charge control agent for increasing the charge amount of the positively chargeable developer. However, in the present invention, the quaternary phosphonium salt may be used in combination with a binder resin having at least one structure selected from the group consisting of —NH ₂ group, ═NH group and —NH— bond in the molecular structure. is important. By using a quaternary phosphonium salt together with this binder resin, the quaternary phosphonium salt itself works to relieve the positive chargeability, and the excessive friction of the negatively charged developer due to the addition of the aromatic oxycarboxylic acid metal compound. The effect of suppressing charging can be remarkably exhibited.

  The resin composition for forming the surface layer preferably has the quaternary phosphonium salt in an amount of 1 to 20 parts by mass, more preferably 1 to 10 parts by mass, with respect to 100 parts by mass of the binder resin. It is. By making the addition amount 1 part by mass or more, it is possible to further exert the effect of suppressing the excessive charge of the developer, and by making it 20 parts by mass or less, it is possible to suppress the excessive charge of the developer while maintaining the durability of the surface layer. Further improvement is possible. Furthermore, it is more preferable to set it to 10 parts by mass or less because a highly durable surface layer can be obtained.

  In addition, the presence of the component derived from the quaternary phosphonium salt in the surface layer may be caused by, for example, collecting samples collected by grinding the surface layer of the developer carrier or extracting with a solvent such as chloroform by GC / MS, LC / MS. It can be confirmed by analyzing with an analyzer such as GC / MS is a gas chromatograph mass spectrometer, and LC / MS is a liquid chromatograph mass spectrometer.

(Quaternary ammonium salt)
The structure of the quaternary ammonium salt preferably has a structure represented by the following formula (2) from the viewpoint of suppressing excessive charging.

(2)

(In the formula (2), R ₁ to R ₄ are each independently, 1 or more carbon atoms which may have a substituent group 18 an alkyl group, an optionally substituted phenyl group, the substituent have a representative of a naphthyl group or an optionally substituted benzyl group, .X ^- is a halogen ion, OH ^- it represents an or an organic acid ion).

  Examples of the substituent that each of the phenyl group, naphthyl group, and benzyl group may have independently include a halogen group, a nitro group, a hydroxyl group, and an organic acid group (for example, a sulfo group and a carboxyl group). be able to.

  Examples of organic acid ions include organic sulfate ions, organic sulfonate ions, organic phosphate ions, molybdate ions, tungstate ions, and heteropolyacid ions containing molybdenum atoms or tungsten atoms.

X ⁻ in the formula (1) is more preferably an organic acid ion from the viewpoint of suppressing application of excessive frictional charge, and more preferably an organic sulfonate ion among them.

  Although the specific example of a quaternary ammonium salt is shown in following Table 2, of course, this invention is not limited to these. In Table 2, “Ph group” represents a phenyl group.

  Similar to the quaternary phosphonium salt, the quaternary ammonium salt is generally used as a positively chargeable charge control agent for increasing the charge amount of the positively chargeable developer. However, in the present invention, by adding a quaternary ammonium salt together with a metal compound of an aromatic oxycarboxylic acid to the binder resin according to the present invention, the interaction is similar to the case where the quaternary phosphonium salt is added. As a result, reverse triboelectric charge imparting properties are exhibited. As a result, it is possible to maintain the triboelectric charging stability of the developer while preventing overcharging of the developer on the developer carrying member, and as a result, it is possible to obtain good development characteristics.

  In addition, the presence of components derived from the quaternary ammonium salt in the surface layer is determined by, for example, samples collected by grinding from the surface of the developer carrier or extraction with a solvent such as chloroform by GC / MS, LC / MS. This can be confirmed by measuring with

  The resin composition for forming the surface layer preferably has the quaternary ammonium salt in an amount of 1 part by mass or more and 20 parts by mass or less, more preferably 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the binder resin. It is. The addition amount of 1 part by mass or more can further exert the effect of suppressing the excessive charge of the developer, and the addition amount of 20 parts by mass or less further suppresses the overcharge while maintaining the durability of the surface layer. It becomes possible to improve. Furthermore, it is more preferable to set it to 10 parts by mass or less because a highly durable surface layer can be obtained.

-Aromatic oxycarboxylic acid metal compound In the present invention, an aromatic oxycarboxylic acid metal compound is contained in the resin composition for forming the surface layer to impart appropriate triboelectric charge to the developer. It is necessary to do.

  Examples of the aromatic oxycarboxylic acid include salicylic acid, 3-methylsalicylic acid, 4-methylsalicylic acid, 5-methylsalicylic acid, 3,5-di-tert-butylsalicylic acid, 4-chlorosalicylic acid, 5-chlorosalicylic acid, 3, 5-Dichlorosalicylic acid, 3-methoxysalicylic acid, 4-methoxysalicylic acid, 1-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 3-hydroxy-7-methoxy-2-naphthoic acid can be suitably used. .

  The metal in the aromatic oxycarboxylic acid metal compound is preferably a divalent or higher metal. Examples of the divalent metal include Mg, Ca, Sr, Pb, Fe, Co, Ni, Zn, Cu, and Zr. Examples of the trivalent or higher metal include Al, Cr, Fe, Ni, and Zr.

  Among these metals, any metal selected from the group consisting of Al, Cr, Zn, and Zr is more preferable because appropriate triboelectric charge is imparted to the negatively chargeable developer.

  The resin composition for forming the surface layer preferably has a metal compound of aromatic oxycarboxylic acid in an amount of 1 part by mass to 40 parts by mass with respect to 100 parts by mass of the binder resin. More preferably. When the addition amount is 1 part by mass or more, an excessive charge suppressing effect can be further exhibited, and more preferably, 5 parts by mass or more can further exhibit the excessive charge suppressing effect. By controlling the amount to 40 parts by mass or less, it is possible to further improve the suppression of overcharge while maintaining the durability of the surface layer. Furthermore, it is more preferable to set it to 35 parts by mass or less because a highly durable surface layer can be obtained.

  In addition, the presence of a component derived from an aromatic oxycarboxylic acid metal compound in the surface layer is measured by, for example, a sample collected by grinding from the surface of the developer carrier or extraction with a solvent such as chloroform with an analyzer. Can be confirmed. As an analyzer, GC / MS, LC / MS, and an ultraviolet-visible spectrophotometer can be used.

-Conductive particle In this invention, in order to adjust the resistance value of a surface layer, electroconductive particle is contained in the resin composition for forming a surface layer. As the conductive particles, known conductive particles in the field of the developer carrying member can be appropriately selected and used. Examples of the conductive particles include the following.

  Fine powder of metal (aluminum, copper, nickel, silver, etc.), particles of conductive metal oxide (eg antimony oxide, indium oxide, tin oxide, titanium oxide, zinc oxide, molybdenum oxide, potassium titanate), graphite particles, Crystalline graphite, various carbon fibers, conductive carbon black.

  The said electroconductive particle may be used individually by 1 type, and may mix and use 2 or more types.

  Among the conductive particles described above, conductive carbon black, especially conductive amorphous carbon, is particularly excellent in electrical conductivity, is charged with a polymer material, imparts conductivity, and simply controls the amount added. Arbitrary conductivity can be obtained to some extent, which is preferable. Further, the dispersion stability and coating stability are also improved due to the thixotropic effect of the paint. The amount of carbon black added varies depending on the particle size, but is preferably in the range of 1 to 100 parts by mass with respect to 100 parts by mass of the binder resin. By setting it within this range, the volume resistance value of the surface layer can be brought to a desired level, and the strength of the surface layer can be sufficiently maintained.

Among the above conductive particles, graphite particles and crystalline graphite are preferable because they are excellent in conductivity and added to the surface layer to increase surface lubricity and improve the durability of the surface layer. In particular, graphite particles having a graphitization degree p (002) of 0.20 to 0.95 are more preferable because the coating strength of the surface layer and the lubricity of the surface layer can be improved. The graphitization degree p (002) is said to be the Franklin p value, and is obtained by the following formula I from the lattice spacing d (002) of graphite obtained from the X-ray diffraction diagram of the graphite particles. This p (002) value indicates the proportion of disordered portions of the stack of carbon hexagonal mesh planes. The smaller this value, the greater the degree of graphitization.
d (002) = 3.440-0.086 (1 -p 2) Formula I
The addition amount of graphite particles and crystalline graphite varies depending on the particle diameter, but is preferably in the range of 1 part by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the binder resin. By making it within this range, the surface layer can be provided with sufficient conductivity and surface lubricity.

  The volume average particle size of the conductive particles is preferably 10 nm or more from the viewpoint of dispersion stability and 20 μm or less from the viewpoint of resistance uniformity of the resin composition.

-Other additives The resin composition for forming the surface layer is provided with unevenness-imparting particles for forming unevenness from the viewpoint of making the surface roughness of the developer carrier uniform and maintaining appropriate surface roughness. It is preferable to include. The unevenness-imparting particles may have conductivity. The volume average particle diameter of the unevenness imparting particles is preferably 1 μm or more and 30 μm or less. If the particle size of the unevenness imparting particles is 1 μm or more, uniform surface unevenness can be formed, and the surface roughness can be increased by adding a small amount. In addition, the weakening of the surface layer can be suppressed, and a decrease in wear resistance can be suppressed. If it is 30 μm or less, the amount of protrusion from the surface layer can be made moderate, and the uneven charging of the developer and the decrease in the charge amount can be suppressed. Moreover, the addition amount of uneven | corrugated particle | grains is 5 mass parts or more from a viewpoint of exhibiting the effect by addition with respect to 100 mass parts of binder resin, and 100 mass parts or less are preferable from a viewpoint of abrasion-resistant maintenance.

<Physical properties of surface layer of developer carrier>
The physical properties of the surface layer of the developer carrier will be described below.

(Layer thickness, volume resistance value and surface roughness of the surface layer)
As the surface roughness of the surface layer, arithmetic average roughness Ra (JIS B0601-2001) is preferably 0.3 μm or more and 3.5 μm or less. If Ra is 0.3 μm or more, the developer is appropriately transported, and it is possible to further suppress the occurrence of thin image density due to the shortage of developer, and the occurrence of scattering and blotch due to excessive charging of the developer. Further, if Ra is 3.5 μm or less, the triboelectric charge can be uniformly applied to the developer, and the occurrence of streak unevenness, reversal fogging, and image density thin due to insufficient charging can be further suppressed.

  The layer thickness of the surface layer formed on the developer carrying member of the present invention is preferably 4 μm or more and 50 μm or less, and particularly preferably 6 μm or more and 30 μm or less. If it is 4 μm or more, the surface layer can be made uniform. If it is 50 micrometers or less, it is easy to control the roughness of a surface layer.

The volume resistance value of the surface layer in the present invention is preferably 1 × 10 ⁻¹ Ω · cm to 1 × 10 ³ Ω · cm, particularly 1 × 10 ⁻¹ Ω · cm to 1 × 10 ^2. It is preferable that it is below Ω · cm. If it is 1 × 10 ⁻¹ Ω · cm or more and 1 × 10 ³ Ω · cm or less, resistance adjustment can be easily performed by adding conductive particles to the resin composition used for forming the surface layer.

<< Method for Producing Developer Carrier >>
In the method for producing a developer carrier according to the present invention, first, a coating material having a resin composition is applied to the surface of a substrate, and a coating film is formed on the surface of the substrate. This resin composition contains i) a binder resin, ii) a quaternary phosphonium salt or a quaternary ammonium salt, iii) a metal compound of an aromatic oxycarboxylic acid, and iv) conductive particles. Thereafter, the coating film is cured (may be dried and solidified) to form a surface layer. In addition, when mixing the material for forming a surface layer, it is preferable to disperse and mix these materials i) to iv) in a solvent to form a paint, which is applied onto the surface of the substrate. The paint is preferably a paint obtained by mixing the materials i) to iv) with a solvent (for example, methanol or isopropyl alcohol) in which i) the binder resin is dissolved. As a dispersion apparatus for dispersing and mixing the materials i) to iv), a known media dispersion apparatus such as a ball mill, a sand mill, an attritor, or a bead mill, a known type using a collision type atomization method or a thin film swirl method is known. A medialess distribution device can be suitably used. Examples of a method for applying the obtained paint to the substrate include known methods such as a dipping method, a spray method, a roll coating method, an electrostatic coating method, and a ring coating method. Examples of the curing method include a heat curing method.

<< Developing device >>
Next, the developing device provided with the developer carrying member according to the present invention will be described below with a specific example. The developing device according to the present invention is not limited to the following.

  The developing device according to the present invention includes at least a negatively chargeable developer, a developer container, a developer carrier, and a developer layer thickness regulating member, and the developer according to the present invention described above is used as the developer carrier. A carrier is used. The developing container contains a negatively chargeable developer. The developer carrier is rotatably held so that a negatively charged developer supplied from a developer container is carried on the surface and conveyed. The developer layer thickness regulating member is for regulating the layer thickness of the negatively chargeable developer layer formed on the developer carrying member.

<Magnetic one-component developing device>
FIG. 1 is a schematic diagram showing an example of a magnetic one-component developing device used when a magnetic one-component developer is used as a developer.

  A developing device shown in FIG. 1 includes a developing container 503 for containing a developer, and a developing sleeve (developing) that holds the developer (not shown) contained in the container on the surface and conveys the developer. Agent carrier) 508. The developing sleeve 508 has a base 506 and a surface layer 507 formed on the base. In the developing sleeve 508, a magnetic roller 509 having magnetic poles (N1, N2, S1, and S2) is provided to magnetically attract and hold the magnetic one-component negatively chargeable developer on the developing sleeve 508. Has been placed.

  The magnetic one-component developer is sent into the developing container 503 from the developer supply container (not shown) via the developer supplying member 512. The developing container 503 is divided into a first chamber 514 and a second chamber 515, and the magnetic one-component developer fed into the first chamber 514 is formed by the developing container 503 and the partition member 504 by the stirring and conveying member 505. It passes through the gap and is sent to the second chamber 515. In the second chamber 515, a stirring and conveying member 511 for preventing the developer from staying is provided.

  In this developing device, first, a magnetic one-component negatively charged developer accommodated in a developing container 503 is carried on the surface of a developer carrying member 508 by the action of magnetic force by a magnet roller 509. The magnetic monocomponent negatively chargeable developer carried on the developer carrier 508 is regulated by the developer layer thickness regulating member 502 to form a developer layer on the developer carrier 508. The developer carrying member 508 rotates in the direction of arrow A, so that the developer carrying member 508 and the electrostatic latent image carrying member (photosensitive drum) 501 carrying the electrostatic latent image face each other. The developer on the developer carrier 508 is conveyed to C. The electrostatic latent image on the electrostatic latent image carrier 501 is developed with the developer conveyed by the developer carrier to form a developer image. The electrostatic latent image carrier 501 rotates in the direction of arrow B.

  FIG. 2 is a schematic diagram showing another example of a magnetic one-component developing device used when a magnetic one-component developer is used as a developer.

  The magnetic one-component developer is a friction capable of developing the electrostatic latent image on the electrostatic latent image carrier 501 by friction between the particles of the magnetic developer and friction with the surface layer on the developer carrier. Get a charged charge. In order to regulate the layer thickness of the developer layer conveyed to the development region C, an elastic blade 516 as a developer layer thickness regulating member is used. The elastic blade 516 can be formed of an elastic plate using a material having rubber elasticity such as urethane rubber and silicone rubber, or a material having metal elasticity such as phosphor bronze and stainless steel. The developer carrying member 508 may be contacted or pressed through a magnetic one-component developer.

  The layer thickness of the magnetic one-component developer formed on the developer carrier 508 is thinner than the minimum gap between the developer carrier 508 and the photosensitive drum 501 in the development region C from the viewpoint of high image quality. It is preferable that

  It is effective to incorporate the developer carrying member according to the present invention in a developing device that develops an electrostatic latent image with a magnetic one-component developer as described above, that is, a non-contact developing device.

  Further, in order to cause the magnetic one-component developer carried on the developer carrying member 508 to fly, a developing bias voltage is applied to the developer carrying member 508 by a developing bias power source 513 as bias means. When a DC voltage is used as the developing bias voltage, a voltage having a value between the potential of the image portion of the electrostatic latent image (the region visualized as the developer adheres) and the potential of the background portion is carried by the developer. Application to the body 508 is preferred.

  In order to increase the density of the developed image and improve the gradation, an alternating bias voltage is applied to the developer carrier 508 to form an oscillating electric field whose direction is alternately reversed in the development region C. Good. In this case, it is preferable to apply to the developer carrier 508 an alternating bias voltage in which a DC voltage component having an intermediate value between the potential of the developed image portion and the potential of the background portion is superimposed.

  In FIG. 1, as a developer layer thickness regulating member that regulates the layer thickness of the magnetic one-component developer layer on the developer carrier 508, a magnetic blade 502 that is spaced apart from the developer carrier 508 is provided. Used.

  The magnetic blade 502 is usually mounted on the developer container 503 so as to face the developer carrier 508 with a gap of 50 μm or more and 500 μm or less from the surface of the developer carrier 508. The magnetic lines of force from the magnetic pole N1 of the magnet roller 509 are concentrated on the magnetic blade 502, whereby a thin layer of magnetic one-component developer is formed on the developer carrier 508. In the present invention, a nonmagnetic developer layer thickness regulating member can be used instead of the magnetic blade 502. As described above, the developing device equipped with the developer carrier of the present invention may use an elastic blade that can contact the carrier via the developer as the developer layer regulating member. Magnetic blades that are spaced apart may be used.

<Non-magnetic two-component developing device>
FIG. 3 is a schematic diagram showing an example of a nonmagnetic two-component developing device used when a nonmagnetic two-component developer having a magnetic carrier and a developer is used as the developer.

  In FIG. 3, a developing sleeve (developer carrier) 1 as a developer carrier is provided in the developing chamber 11 of the developer container 5 so as to face the electrostatic latent image carrier 4 rotated in the direction of arrow a. Yes. In this developer carrier 1, a magnetic roller 2 as a magnetic field generating means is immovably arranged, and the magnetic roller 2 is arranged in the order of S1, N1, S2, N2, N3 is magnetized.

  A two-component developer 8 in which the toner 7 and the magnetic carrier 10 are mixed is accommodated in the developing chamber 11. The two-component developer 8 is fed into the stirring chamber 9 of the developing container 5 through one opening (not shown) of the partition wall 13 open at the upper end at one end of the developing chamber 11. The toner 7 is replenished from the toner chamber 12 into the stirring chamber 9 and conveyed to the other end of the stirring chamber 9 while being mixed by the first developer stirring / conveying means 14 in the stirring chamber 9. The two-component developer 8 conveyed to the other end of the stirring chamber 9 is returned to the developing chamber 11 through the other opening (not shown) of the partition wall 13. The two-component developer moved to the developing chamber 11 is a second developer agitating / conveying means 15 and a third developer agitating / conveying means that conveys the developer in a direction opposite to the conveying direction by the second developer agitating / conveying means 15. The toner is conveyed to the developer carrying member 1 while being stirred and conveyed by the conveying means 16.

  The two-component developer 8 supplied to the developer carrier 1 is magnetically constrained by the magnetic force of the magnet roller 2 and is carried on the surface of the developer carrier 1. Then, the developer carrying member 1 rotates clockwise with respect to the cross section shown in FIG. 3, and the developer carrying member 1 is regulated by the developer regulating member blade 3 provided substantially on the top of the developer carrying member 1. A thin layer of the two-component developer 8 is formed above. Thereafter, the two-component developer 8 is transported to the development area C facing the electrostatic latent image carrier 4, where the toner 7 in the two-component developer 8 is transferred to the electrostatic latent image carrier 4. Used for image development. The remaining two-component developer 8 that has not been consumed for development is collected in the developer container 5 by the rotation of the developer carrier 1. In the developing container 5, the remaining two-component developer 8 that has not been developed and is magnetically restrained on the developer carrier 1 is peeled off by the repulsive magnetic field between N2 and N3 of the same polarity. .

  In order to prevent toner scattering when the two-component developer 8 rises along the lines of magnetic force due to the magnetic pole N2, the elastic seal member 6 contacts one end of the two-component developer 8 at the bottom of the developing container 5. It is fixed and installed.

  FIG. 3 merely schematically shows the developing device, and it goes without saying that there are various forms in the shape of the developing container 5, the presence / absence of a stirring blade / conveying member, and the arrangement of magnetic poles of the magnetic roller.

<Developer>
The developer (toner) used in the developing device according to the present invention is negatively charged. In addition, this negatively chargeable developer uses a conventionally known material (for example, a binder resin, a charge control agent, a magnetic material, a colorant, a release agent, an inorganic fine powder, or the like) and a conventionally known production. What can be obtained by the method can be used.

  The particles (developer particles) constituting the developer used in the present invention preferably have a weight average particle diameter in the range of 4 μm or more and 8 μm or less from the viewpoint of high image quality. By using a developer in the above range, it is possible to easily balance the image quality and the image density. In order to achieve stable image density and image quality, the developer is preferably closer to a sphere, that is, the average circularity of developer particles is preferably close to 1.0. Specifically, in the circularity distribution of the magnetic developer particles, the number of particles having a relatively high circularity of 0.93 or more is preferably included in the developer by 60% by number or more, more preferably 75% by number or more. It is. When it is 60% by number or more, even when used repeatedly for a long period of time, it is difficult to cause a phenomenon such as a decrease in triboelectric charge amount or contamination of the developer carrier, and a decrease in image density is unlikely to occur.

  As the binder resin used for the developer, generally known resins can be used, and examples thereof include vinyl resins, polyester resins, polyurethane resins, epoxy resins, and phenol resins. Among these, vinyl resins or polyester resins are preferable from the viewpoints of developability and fixability.

  For the purpose of improving the triboelectric charge characteristics, a charge control agent can be included in the developer particles (internal addition) or mixed with the developer particles (external addition). By adding the charge control agent, it is possible to easily control the triboelectric charge amount according to the development system.

  When the developer is a magnetic developer, examples of magnetic materials include iron oxide metal oxides such as magnetite, maghemite, and ferrite, magnetic metals such as Fe, Co, and Ni, these metals and Al, Mixing alloys with metals such as Co, Cu, Pb, Mg, Ni, Sn, Zn, Sb, Be, Bi, Cd, Ca, Mn, Se, Ti, W, and V, or mixtures thereof it can. In this case, these magnetic materials may also serve as a colorant.

  As the colorant contained in the developer, a conventionally known pigment or dye can be used.

  In addition, the developer preferably contains a release agent from the viewpoint of preventing winding around the fixing device, and for example, Fischer-Tropsch wax can be used as the release agent.

  Furthermore, inorganic fine powders such as silica, titanium oxide, and alumina may be externally added to the developer in order to improve environmental stability, charging stability, developability, fluidity, storage stability and cleaning properties. preferable. Among these, silica fine powder is more preferable.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

<< Measurement method >>
First, detection methods of various substances and measurement methods of various physical properties related to the present invention will be described below.

[1] Detection of components derived from quaternary phosphonium salts and quaternary ammonium salts Using LC / MS (trade name: Agilent 1200/6100, manufactured by Agilent Technologies, Inc.) equipped with an electrospray ionization device, the following In this way, the presence of components derived from the quaternary phosphonium salt and quaternary ammonium salt in the surface layer of the developer carrying member was confirmed.

First, a developer carrying body having a surface layer was immersed in methanol to obtain a methanol solution containing an eluate from the surface layer. The obtained methanol solution containing the eluate was attached to LC / MS as a sample, ionized by electrospray ionization (ESI), and measured by LC / MS. In LC / MS, positive ion mode in which proton-added ions ([M + H] ⁺ ) generated by ESI are detected and measured, and negative ion in which proton-desorbed ions ([M + H] ⁻ ) are detected and measured. Measured in both modes of mode.

[2] Detection of components derived from metal compound of aromatic oxycarboxylic acid Surface layer of developer carrier using ultraviolet-visible spectrophotometer (trade name: V560, manufactured by JASCO Corporation) according to the method described below Thus, the presence of a component derived from a metal compound of an aromatic oxycarboxylic acid was confirmed.

  A developer carrying body having a surface layer was immersed in methanol to obtain a methanol solution containing an eluate from the surface layer. The obtained methanol solution was measured with an ultraviolet-visible spectrophotometer.

[3] Measurement of surface layer thickness and scraping amount Using a dimensional measuring instrument (trade name: LS5000 series) manufactured by Keyence Corporation that measures the outer diameter of a cylinder with laser light, a developer carrier before forming the surface layer The outer diameter (S ₀ ), the outer diameter after forming the surface layer (S ₁ ), and the outer diameter after durable use (S ₂ ) were measured. From these values, the thickness of the surface layer (S ₁ -S ₀ ) and the amount of surface layer abrasion (film abrasion) (S ₁ -S ₂ ) were calculated.

  For the measurement, a controller LS-5500 (trade name) and a sensor head LS-5040T (trade name) of the apparatus were used. After separately fixing the sensor unit to the device equipped with the developer carrier fixing jig and the sleeve feed mechanism, and dividing it into 30 parts in the longitudinal direction of the developer carrier and rotating the sleeve 90 ° in the circumferential direction Further, the outer diameter size of the developer carrier was measured at 30 locations, ie, 60 locations in total. The outer diameter dimension was the average value, and the measurement environment was a temperature of 20 ° C. or more and 25 ° C. or less and a humidity of 50% RH or more and 60% RH or less. The measurement of the outer diameter of the developer-carrying member after durable use was carried out after removing the developer adhesion adhered or fused on the surface by ultrasonic cleaning in methyl ethyl ketone for 1 minute.

[4] Measurement of Volume Average Particle Size of Conductive Particles and Concavity / Concavity-Providing Particles The volume average particle size of the conductive particles and concavity / concavity-providing particles contained in the surface layer is measured by a laser diffraction particle size distribution meter (trade name: Coulter LS- 230 type particle size distribution meter, manufactured by Beckman Coulter, Inc.).

  As a specific measuring method, first, a small amount module was used, and isopropyl alcohol (IPA) was used as a measuring solvent. The measurement system of the particle size distribution meter was washed with this IPA for 5 minutes, and the background function was executed after washing. Next, 1 mg or more and 25 mg or less of a measurement sample (conductive particles or unevenness imparting particles) was added to 50 ml of IPA, and the obtained suspension was subjected to dispersion treatment for 3 minutes with an ultrasonic disperser to obtain a test sample solution. Then, gradually add this test sample solution into the measurement system of the measurement device, and adjust the sample concentration in the measurement system so that the PIDS (polarized light scattering intensity difference) on the screen of the device is 45% or more and 55% or less. The volume average particle diameter calculated from the volume distribution was determined.

[5] Volume resistance measurement of surface layer of developer carrier 7 μm or more and 25 μm using the same paint constituting the surface layer on the developer carrier on a 100 μm thick PET (polyethylene terephthalate) sheet as a measurement sample A surface layer having the following thickness was formed. As a measuring device, the resistivity meter Loresta GP (low resistance) or Hiresta UP (high resistance) (both trade names, manufactured by Mitsubishi Chemical Analytech Co., Ltd.) are used depending on the resistance value, and the volume resistance value is measured using a 4-terminal probe. It was measured. The volume resistance was measured at a measurement environment of a temperature of 20 ° C. to 25 ° C. and a humidity of 50% RH to 60% RH.

[6] Particle size measurement of developer particles As a measurement device, a particle size distribution measurement device (trade name: Coulter Multisizer III, manufactured by Beckman Coulter, Inc.) was used. Further, an electrolytic solution (trade name: ISOTON-II, manufactured by Beckman Coulter, Inc.) was used. First, 0.1 ml or more and 5 ml or less of a surfactant (alkylbenzene sulfonate solution) was added as a dispersant in 100 ml or more and 150 ml or less of the electrolytic solution, and then 2 mg or more and 20 mg or less of a sample (developer) was added. This was subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute to 3 minutes to prepare a measurement sample. Then, the volume and number of developer particles in the test sample were measured using a 100 μm aperture of a measuring device.

  The volume distribution and the number distribution are calculated from the measurement results, and the weight-based weight average particle diameter (D4) obtained from the volume distribution and the number-based length average particle diameter (D1) obtained from the number distribution (both for each channel). The median value of the channel is the representative value for each channel).

[7] Measurement of average circularity of developer particles The average circularity of developer particles is measured and analyzed under a calibration operation using a flow type particle image analyzer (trade name: “FPIA-3000”, manufactured by Sysmex Corporation). Measured with

  A specific measurement method is as follows. First, about 20 ml of ion-exchanged water from which impure solids were previously removed was put in a glass container. About 0.2 ml of a diluted solution obtained by diluting the dispersant with ion-exchanged water about 3 times by mass was added thereto. Here, as a dispersant, a trade name: “Contaminone N” (a nonionic surfactant, an anionic surfactant, a 10% by weight aqueous solution of a neutral detergent for cleaning a precision measuring instrument having a pH of 7 consisting of an organic builder, Kogure Pharmaceutical Co., Ltd.) was used. Further, about 0.02 g of a measurement sample (developer) was added, and dispersion treatment was performed for 2 minutes using an ultrasonic disperser to obtain a dispersion for measurement. In that case, it cooled suitably so that the temperature of a dispersion liquid might be 10 degreeC or more and 40 degrees C or less. As the ultrasonic disperser, a desktop type ultrasonic cleaner disperser (trade name: “VS-150” (manufactured by Vervo Creer)) having an oscillation frequency of 50 kHz and an electric output of 150 W is used. Of ion exchange water was added, and about 2 ml of the above-mentioned Contaminone N was added to this water tank.

  For the measurement, the flow type particle image analyzer equipped with a trade name: “UPlanApro” (magnification: 10 ×, numerical aperture: 0.40) as an objective lens is used, and the sheath liquid is a particle sheath trade name: “PSE-900A”. (Sysmex Corporation) was used. The dispersion prepared according to the above procedure was introduced into the flow type particle image analyzer, and 3000 developer particles were measured in the total count mode in the HPF measurement mode. Then, the binarization threshold at the time of particle analysis was set to 85%, the analysis particle diameter was limited to a circle equivalent diameter of 1.985 μm or more and less than 39.69 μm, and the average circularity of developer particles was determined.

  In the measurement, automatic focus adjustment was performed using standard latex particles (for example, “RESEARCH AND TEST PARTICLESLATEx Microsphere Suspensions 5200A” diluted with ion-exchanged water) manufactured by Duke Scientific before the measurement was started. Thereafter, focus adjustment was performed every 2 hours from the start of measurement.

[8] Measurement of glass transition temperature (Tg) of binder resin used for developer and melting point of wax The glass transition temperature (Tg) of binder resin and the melting point of wax are measured by a differential scanning calorimeter, trade name: “Q1000 ”(Manufactured by TA Instruments) according to ASTM D3418-82.

  For the temperature correction of the device detector, the melting points of indium and zinc were used, and for the correction of heat quantity, the heat of fusion of indium was used.

  Specifically, about 10 mg of toner is precisely weighed, put in an aluminum pan, and an empty aluminum pan is used as a reference. Measurements were made at ° C / min. In the measurement, the temperature was once raised to 200 ° C., subsequently lowered to 30 ° C., and then the temperature was raised again. The maximum endothermic peak of the DSC curve in the temperature range of 30 to 200 ° C. in the second temperature raising process was defined as the maximum endothermic peak of the endothermic curve in the DSC measurement of the toner. Moreover, a specific heat change is obtained in the temperature range of 40 to 100 ° C. during this temperature raising process. At this time, the intersection of the intermediate point line of the baseline before and after the change in specific heat and the differential heat curve was defined as the glass transition temperature Tg of the binder resin.

[9] Measurement of magnetic properties of magnetic iron oxide particles contained in developer Using a vibrating sample magnetometer (trade name: VSM-P7, manufactured by Toei Kogyo Co., Ltd.), sample temperature 25 ° C., external magnetic field 795. The magnetic properties (coercivity (Hc), magnetization strength (σs), residual magnetization (σr)) of the magnetic iron oxide particles were measured at 8 kA / m.

[10] Measurement of average primary particle diameter of magnetic iron oxide particles, silica particles, and titanium oxide particles The average primary particle diameter of these particles is determined with a scanning electron microscope (magnification 40000 times to 400000 times). It can be specified by observing and measuring the ferret diameter of each of the 200 particles to determine the number average particle diameter. In Examples described later, a scanning electron microscope (trade name: S-4800, manufactured by Hitachi, Ltd.) was used.

[11] Measurement of 50% particle size (D50) based on volume distribution of magnetic carrier The particle size distribution is measured with a laser diffraction / scattering particle size distribution measuring device (trade name: Microtrac MT3300EX, manufactured by Nikkiso Co., Ltd.). went. For the measurement, a sample feeder for dry measurement (trade name: One Shot Dry Sample Conditioner Turbotrac, manufactured by Nikkiso Co., Ltd.) was attached. As the supply conditions of Turbotrac, a dust collector was used as a vacuum source, the air volume was about 33 liters / sec, and the pressure was about 17 kPa. Control was automatically performed on the software, and a 50% particle size (D50), which is a cumulative value based on volume distribution, was obtained. Control and analysis were performed using attached software (version 10.3.3-202D).

<< Developer carrier >>
Hereinafter, various materials used for the developer carrier will be described.

<Conductive particles>
As the conductive particles used for the surface layer of the developer carrying member, the following conductive particles A-1 to A-3 were used.

[Conductive Particle A-1]
The β-resin was extracted from the coal tar pitch by solvent fractionation, hydrogenated and heavyized, and then the solvent-soluble component was removed with toluene to obtain a mesophase pitch. The mesophase pitch powder is finely pulverized, oxidized in air at about 300 ° C., and then heat treated at 2800 ° C. in a nitrogen atmosphere. After classification, the volume average particle size is 3.4 μm, and the graphitization degree is p. Conductive particles A-1 having (002) of 0.39 were obtained. The degree of graphitization p (002) is said to be the Franklin p value, and is obtained from the lattice spacing d (002) of graphite obtained from the X-ray diffraction pattern of the graphite particles by the following formula. This p (002) value indicates the proportion of disordered portions of the stack of carbon hexagonal mesh planes. The smaller this value, the greater the degree of graphitization.

[Conductive particles A-2]
As a raw material, a mixture of coke and tar pitch was used, and this mixture was kneaded at a temperature equal to or higher than the softening point of tar pitch, extruded, and primarily calcined at 1000 ° C. in a nitrogen atmosphere. Subsequently, impregnation with coal tar pitch was performed, followed by secondary firing at 2800 ° C. in a nitrogen atmosphere to graphitize, and further pulverize and classify to obtain conductive particles A-2 having a volume average particle size of 4.0 μm. .

[Conductive particles A-3]
Carbon black (trade name: Toka Black # 5500, manufactured by Tokai Carbon Co., Ltd.) was used as the conductive particles A-3.

<Binder resin>
As binder resins used for the surface layer of the developer carrier, the following binder resins B-1 to B-3 and binder resins b-1 to b-2 were used.

[Binder resin B-1]
Resol type phenol resin using ammonia catalyst (trade name: J-325CA, manufactured by DIC Corporation) was used as binder resin B-1.

[Binder resin B-2]
A blend of polyol (trade name: Nipponporan 5037, manufactured by Nippon Polyurethane Industry Co., Ltd.) and a curing agent (trade name: Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.) at a mass ratio of 10: 1 is used as binder resin B-2. It was.

[Binder resin B-3]
6/66/610 copolymer nylon (trade name: Elbamide 8023, manufactured by DuPont) was used as binder resin B-3.

[Binder resin b-1]
A NaOH-type resol type phenol resin GF9000 (trade name, manufactured by DIC Chemical Industries, Ltd.) was used as the binder resin b-1.

[Binder resin b-2]
Silicone resin SH804 (trade name, manufactured by Toray Dow Corning) was used as binder resin b-2.

<Quaternary phosphonium salt>
The following phosphonium salts C-1 to C-3 were used as the quaternary phosphonium salts used for the surface layer of the developer carrier.

[Quaternary phosphonium salt C-1]
Example No. 1 shown in Table 1 No. 1 quaternary phosphonium salt (trade name: Hishicolin BTPPBr, manufactured by Nippon Chemical Industry Co., Ltd.) was used as the quaternary phosphonium salt C-1.

[Quaternary phosphonium salt C-2]
Example No. 1 shown in Table 1 A quaternary phosphonium salt (trade name: Hishicolin PX-2H, manufactured by Nippon Chemical Industry Co., Ltd.), which is compound No. 9, was used as the phosphonium salt C-2.

[Quaternary phosphonium salt C-3]
A quaternary phosphonium salt represented by the following formula (4) (trade name: di-tert-butylmethylphosphonium tetraphenylborate, manufactured by Tokyo Chemical Industry Co., Ltd.) was used as the quaternary phosphonium salt C-3.

(4)

<Quaternary ammonium salt>
The following quaternary ammonium salts D-1, D-2, and D-3 were used as the quaternary ammonium salts used for the surface layer of the developer carrier.

[Quaternary ammonium salt D-1]
As the quaternary ammonium salt D-1, the example No. shown in Table 2 was used. A quaternary ammonium salt (trade name: Bontron P-51, manufactured by Orient Chemical Co., Ltd.), which is compound No. 1, was used.

[Quaternary ammonium salt D-2]
As the quaternary ammonium salt D-2, a quaternary ammonium salt represented by the following formula (5) (trade name: ARCARD 22-80, manufactured by Lion Akzo Corporation) was used.

(5)

[Quaternary ammonium salt D-3]
As the quaternary ammonium salt D-3, the example Nos. Shown in Table 2 were used. 16 was used (trade name: TP-415, manufactured by Hodogaya Chemical Co., Ltd.).

<Aromatic oxycarboxylic acid metal compound>
The following aromatic oxycarboxylic acid metal compounds E-1 to E-5 were used as the aromatic oxycarboxylic acid metal compounds used for the surface layer of the developer carrier.

[Metal Compound E-1 of Aromatic Oxycarboxylic Acid]
As the metal compound E-1 of an aromatic oxycarboxylic acid, an aluminum compound of 3,5-di-tertiary butylsalicylic acid (trade name: Bontron E101, manufactured by Orient Chemical Industries) was used.

[Metal compound E-2 of aromatic oxycarboxylic acid]
As the metal compound E-2 of the aromatic oxycarboxylic acid, a chromium compound of 3,5-di-tertiarybutyl salicylic acid (trade name: Bontron E81, manufactured by Orient Chemical Industries) was used.

[Metal Compound E-3 of Aromatic Oxycarboxylic Acid]
As the metal compound E-3 of the aromatic oxycarboxylic acid, a zinc compound of 3,5-di-tertiary butylsalicylic acid (trade name: Bontron E84, manufactured by Orient Chemical Industries) was used.

[Metal Compound E-4 of Aromatic Oxycarboxylic Acid]
A zirconium compound of 3,5-di-tertiary butylsalicylic acid (trade name: TN105, manufactured by Hodogaya Chemical Co., Ltd.) was used as the metal compound E-4 of the aromatic oxycarboxylic acid.

[Metal Compound E-5 of Aromatic Oxycarboxylic Acid]
As the metal compound E-5 of the aromatic oxycarboxylic acid, an iron compound of 3,5-di-tertiary butylsalicylic acid (trade name: Bontron X11, manufactured by Hodogaya Chemical Co., Ltd.) was used.

<Roughness imparting particles>
The following unevenness imparting particles F-1 and F-2 were used as the unevenness imparting particles used for the surface layer of the developer carrier.

[Unevenness imparting particles F-1]
Spherical carbon particles (trade name: Nikabead ICB1020, manufactured by Nippon Carbon Co., Ltd.) were used as the unevenness imparting particles F-1.

[Unevenness imparting particles F-2]
Spherical carbon particles (trade name: Nikabead ICB0520, manufactured by Nippon Carbon Co., Ltd.) were used as the unevenness imparting particles F-2.

<< Developer >>
The following developers were used for evaluation.

  [Developer Z-1]

  The raw material 1 for synthesizing the binder resin shown in Table 3 was charged into a four-necked flask together with an esterification catalyst (dibutyltin oxide), and a pressure reducing device, a water separator, a nitrogen gas introducing device, a temperature measuring device, and a stirring device were attached. And stirred at 135 ° C. under a nitrogen atmosphere. At this time, in order to obtain a desired cross-linked structure, fumaric acid was added in portions in the early and late stages of the reaction. The raw material 2 for synthesizing the binder resin (styrene: 84 mol% and 2 ethylhexyl acrylate: 14 mol%) and a mixture of benzoyl peroxide 2 mol% as a polymerization initiator were dropped from the dropping funnel over 4 hours. . Then, after reacting at 135 ° C. for 5 hours, the reaction temperature at the time of polycondensation was raised to 230 ° C. to carry out a condensation polymerization reaction. After completion of the reaction, the reaction product was taken out from the container, cooled and pulverized to obtain a binder resin 1. This binder resin 1 had a number average molecular weight (Mn) of 3,500, a glass transition temperature (Tg) of 54.5 ° C., and a softening point of 135.5 ° C.

  The raw material 3 for synthesizing the binder resin shown in Table 4 was charged into a four-necked flask together with an esterification catalyst (dibutyltin oxide), and a decompression device, a water separation device, a nitrogen gas introduction device, a temperature measurement device, and a stirring device were installed. And stirred at 135 ° C. under a nitrogen atmosphere. The raw material 4 for synthesizing the binder resin (styrene: 84 mol% and 2 ethylhexyl acrylate: 14 mol%) and a mixture of benzoyl peroxide 2 mol% as a polymerization initiator were dropped from the dropping funnel over 4 hours. . Then, after reacting at 135 ° C. for 5 hours, the reaction temperature at the time of polycondensation was raised to 230 ° C. to carry out a condensation polymerization reaction. After completion of the reaction, it was taken out from the container, cooled and pulverized to obtain a binder resin 2. This binder resin 2 had a number average molecular weight (Mn) of 6500, a glass transition temperature (Tg) of 56.8 ° C., and a softening point of 99.0 ° C.

  Next, 85 parts by mass of the binder resin 1 and 15 parts by mass of the binder resin 2 were mixed with a Henschel mixer to obtain a binder resin G-1.

  Subsequently, the materials shown in Table 5 were premixed with a Henschel mixer and then melt kneaded with a biaxial kneading extruder. At this time, the residence time was controlled so that the temperature of the kneaded resin was 150 ° C.

  The obtained kneaded product was cooled and coarsely pulverized with a hammer mill. Next, fine pulverization was performed using a pulverizer (trade name: Turbo Mill, manufactured by Turbo Industry Co., Ltd.). Here, the surfaces of the rotor and the stator were made of a chromium alloy containing chromium carbide and plated to a thickness of 150 μm and a surface hardness of HV1050. The obtained finely pulverized powder was classified using a multi-division classifier (trade name: Elbow Jet Classifier, manufactured by Nittsu Mining Co., Ltd.) using the Coanda effect to obtain magnetic developer particles having negative triboelectric charging properties. .

To 100 parts by mass of the magnetic developer particles, 1.0 part by mass of hydrophobic silica fine powder (BET specific surface area: 140 m ² / g) and 3.0 parts by mass of strontium titanate are externally added and mixed with an opening of 150 μm. Thus, a negative triboelectric developer Z-1 having a weight average particle size of 5.8 μm and an average circularity of 0.975 was obtained.

[Developer Z-2]
A negative electrode having a weight average particle diameter of 6.5 μm and an average circularity of 0.950 was prepared in the same manner as Developer Z-1, except that the amount of magnetic iron oxide particles added was changed from 50 parts by mass to 60 parts by mass. A triboelectrically magnetic developer Z-2 was obtained.

[Developer Z-3]
-Binder resin 1 70 parts by mass-Binder resin 2 30 parts by mass-Fischer-Tropsch wax 5 parts by mass-Aluminum compound of 3,5-ditertiary butylsalicylic acid (Bontron E101 manufactured by Orient Chemical Co., Ltd.) 0.5 parts by mass Part ・ C. I. Pigment Blue 15: 3 8 parts by mass

  After mixing the above materials with a Henschel mixer (trade name: FM-75 type, manufactured by Mitsui Miike Chemical Co., Ltd.), a twin-screw kneader (trade name: PCM-30 type, Ikekai Tekko Co., Ltd.) set at a temperature of 150 ° C. Kneading). 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 (trade name: T-250, manufactured by Turbo Kogyo Co., Ltd.). Furthermore, the obtained finely pulverized product was classified, and further subjected to spheroidization treatment 5 times using a hybridizer (manufactured by Nara Machinery Co., Ltd.), weight average particle diameter (D4) 5.6 μm, average circularity 0. 962 developer particles 1 were obtained.

  The resulting developer particles 1: 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 masses Parts (primary average particle size 16 nm surface-treated with 20% by mass of hexamethyldisilazane, mixed with Henschel mixer (FM-75 type, manufactured by Mitsui Miike Chemical Co., Ltd.)) to obtain a non-magnetic developer Z-3 The obtained nonmagnetic developer Z-3 had a weight average particle diameter (D4) of 5.6 μm and an average circularity of 0.962.

  The developers Z-1 to Z-3 used in this embodiment all have an average circularity of 0.950 or higher, and thus have high fluidity and are easily charged.

<Magnetic carrier 1>
100 parts by mass of Mn-Mg-ferrite particles having a 50% particle size (D50) of 33 μm based on volume, 1 part by mass of silicone resin (trade name: KR271, manufactured by Shin-Etsu Chemical Co., Ltd.), γ-aminopropyltriethoxysilane A mixed liquid of 5 parts by mass and 98.5 parts by mass of toluene was added, and further dried under reduced pressure at 70 ° C. for 5 hours while stirring and mixing with a solution vacuum kneader to remove the solvent. Then, it baked at 140 degreeC for 2 hours, and sieved with the sieve shaker (300MM-2 type | mold, Tsutsui physics and chemistry machine: 75 micrometers opening), and obtained the magnetic carrier 1 whose D50 is 38 micrometers.

[Example 1]
Methanol was added to the materials shown in Table 6 below to adjust the solid content to 45 mass%, and this was adjusted to a sand mill (trade name: Sand Grinder LSG-4U-08, manufactured by Imex Corporation) (glass beads with a diameter of 1 mm as media particles). Use) for 2 hours. Subsequently, after separating the glass beads using a sieve, methanol was added so that the solid content concentration was 33% by mass to obtain a paint.

  Next, a cylindrical aluminum tube having an outer diameter of 20 mmφ (diameter) masked on the upper and lower end portions (both ends in the axial direction of the substrate) and an arithmetic average roughness (Ra) of 0.2 μm was prepared as the substrate. . The substrate was erected vertically and rotated at a constant speed, and the paint was applied while lowering the spray gun from the upper end of the substrate at a constant speed. Subsequently, a developer carrier T1 was produced by heating and drying the coating layer in a hot air drying oven at a temperature of 150 ° C. for 30 minutes.

The layer thickness of the surface layer of the developer carrier T1 was 17 μm, the surface roughness Ra was 1.34 μm, and the volume resistance value of the surface layer was 6 × 10 ⁻¹ Ω · cm. The table shows the additive materials and physical properties of the developer carrier T1 surface layer. In Table 7, “(part)” means part by mass, and “(part)” of the binder resin means part by mass of resin solids.

  The surface layer of the developer carrier T1 was immersed in methanol, and a sample from which the surface layer components were eluted was measured using LC / MS. The peak of m / z = 319.25 was detected by LC / MS (Positive ion mode) measurement, and this peak overlaps with the peak of the C-1 compound alone, so the C-1 compound is contained in the surface layer. It was confirmed that

  Further, the surface layer of the developer carrier T1 was immersed in methanol, and the methanol solution from which the surface layer components were eluted was measured with an ultraviolet-visible spectrophotometer. In the measured spectrum, a peak was detected at 308 nm to 313 nm. Since this peak overlaps with the peak of E-1 alone, it was confirmed that the E-1 compound was contained in the surface layer.

<Evaluation 1>
For the evaluation, an electrophotographic image forming apparatus (trade name: iR2020, manufactured by Canon Inc.) was used. The electrophotographic image forming apparatus is provided with a non-contact type developing apparatus using the magnetic one-component developer shown in FIG. That is, the developing device includes a magnetic one-component developer and an elastic blade as a developer layer thickness regulating member.

  The following evaluation was performed by replacing the developer carrier and the toner provided in the electrophotographic image forming apparatus with the developer carrier T1 and the developer Z-1, respectively.

  The printing is performed in a high temperature and high humidity environment (hereinafter also referred to as H / H) at a temperature of 30 ° C. and a humidity of 80% RH, and a normal temperature and low humidity environment (hereinafter also referred to as N / L) at a temperature of 23 ° C. and a humidity of 5% RH. Made in the environment. Further, as an image sample for printing, a test chart having a printing ratio of 1.5% including characters, solid circle images, and square images was used. The following evaluations (1) to (5) were performed after printing 10 sheets (initial) and after printing 150,000 sheets (after durability).

  The results obtained from the evaluations (1) to (5) below are shown in Tables 8 and 10.

(1) Sleeve Ghost The evaluation of sleeve ghost after printing 10 sheets (initial stage) was performed under the environments of H / H and N / L. As an image sample for evaluation, a solid black square and a circular image are alternately arranged at equal intervals on a white background in an area corresponding to one circumference of the developer carrying member at the front end of the image, and the other portions are halftone. The test chart was used. Then, in the printed matter on which the test chart was printed, how the sleeve ghost of the hieroglyph image appears on the halftone image was visually evaluated.

  Further, after printing 150,000 sheets (after endurance), a printed matter was obtained using the same test chart as in the initial stage, and the sleeve ghost after endurance was evaluated by the same method as in the initial stage.

The evaluation criteria for sleeve ghost evaluation are as follows.
A: No difference in shading is observed.
B: A slight difference in light and shade is seen.
C: A slight difference in density is seen, but the shape of the hieroglyphics cannot be clearly recognized.
D: The density difference appears more than one round of the developing sleeve (developer carrier).

(2) Image quality Evaluation of image quality after printing 10 sheets (initial) was performed under the above H / H and N / L environments. As an image sample for evaluation, a test chart of a line image (line width 190 μm) with an image ratio of 5.5% was used. Then, the printed matter on which this test chart was printed was evaluated by calculating the scattering index (a numerical value representing the blurring of the lines defined by ISO 13660) by measuring with a personal IAS (manufactured by Quality Engineering Associates). .

  Further, after 150,000 sheets were printed (after endurance), a printed matter was obtained using the same test chart as in the initial stage, and the image quality after endurance was evaluated by the same method as in the initial stage.

The evaluation criteria for image quality evaluation are as follows.
A: Spattering index less than 26 B: Scattering index of 26 or more and less than 30 C: Scattering index of 30 or more and less than 34 D: Scattering index of 34 or more

(3) Blotch In the printed matter used in the evaluation after printing 10 sheets (initial) and after printing 150,000 sheets (after endurance) in the N / L environment of “(1) Sleeve Ghost” above, triboelectric charging to the developer The presence or absence of speckled images or wave pattern images (blotches) resulting from poor application was visually observed.

  When the blotch existed, x was described in the column of the evaluation result in Table 8 or 9, and when it did not exist, it was described as ◯.

  In addition, when a blotch is generated in the initial evaluation, the blotch after the endurance is evaluated, and the above “(1) Sleeve Ghost”, “(2) Image Quality”, and “(( 5) Evaluation of “triboelectric charge amount of developer on developer carrying member and photoreceptor” was stopped.

(4) Abrasion resistance of surface layer of developer carrying body Before use and after endurance in the H / H environment of the “(1) Sleeve Ghost”, the outer diameter of the developer carrying body was measured. And the amount of surface layer abrasion was calculated from the difference in outer diameters obtained. The amount of scraping of the surface layer was measured at 30 points at equal intervals in the longitudinal direction of the developer carrier, and further 30 points after rotating the sleeve 90 ° in the circumferential direction, a total of 60 points on the developer carrier. The outer diameter was measured. The average value was taken as the total shaving amount. In measurement after endurance, the surface of the developer carrying member was washed with isopropanol.

(5) Triboelectric charge amount of developer on developer carrier and photoconductor In order to confirm the relationship between sleeve ghost and triboelectric charge amount of developer, the following method is used on the developer carrier and the photoconductor. The triboelectric charge amount of the above developer was measured.

  The amount of triboelectric charge of the developer on the developer carrying member and the photosensitive member was performed in the environments of H / H and N / L. In addition, as an image sample for evaluation, a full solid black image and a full solid white image were used.

  First, a solid black image was printed after printing 10 image samples for printing (initial stage), and printing was interrupted in the middle of the printing. Then, the developer carrying member and the photoconductor are taken out from the electrophotographic image forming apparatus, and the developer carried on the developer carrying member during solid black image development, and the developer carried on the photoconductor are removed. The samples were sucked and collected by a metal cylindrical tube and a cylindrical filter, respectively. At that time, the charge amount Q stored in the condenser through the metal cylindrical tube and the mass M of the collected developer were measured. From these values, the triboelectric charge quantity Q / M (mC / kg) per unit mass of the developer on the developer carrying member and the developer on the photosensitive member at the time of printing a solid black image was calculated.

  Next, the developer carrying member and the photosensitive member were returned to the original positions in the electrophotographic image forming apparatus, and a full white image was printed. Thereafter, the developer carrying member is taken out from the electrophotographic image forming apparatus, and the developer carried on the developer carrying member after the entire solid white image is developed is the same method as when the above-described solid black image is printed. It was collected at. Then, the triboelectric charge amount Q / M (mC / kg) per unit mass of the developer on the developer carrying member at the time of printing the entire solid white image was calculated.

  Next, after printing 150,000 sheets of image samples for printing (after endurance), in the same manner as the measurement of the triboelectric charge amount of the initial developer, the developer is supported when printing a solid black image after endurance. The triboelectric charge amount per unit mass of the developer on the body and the developer on the photoreceptor was calculated. In addition, the triboelectric charge amount per unit mass of the developer on the developer carrying member when printing the entire solid white image was also calculated.

[Examples 2 to 19]
Developer carriers T2 to T19 were produced in the same manner as the developer carrier T1 of Example 1, except that the configuration of the developer carrier was changed as shown in Table 7. In Examples 2 to 19, the developer carrying bodies T2 to T19 obtained were evaluated using the developer Z-1 and in the same manner as in Example 1. The obtained evaluation results are shown in Tables 8, 10 and 11.

  Examples 1 to 19 were good results as shown in Tables 8, 10 and 11.

[Comparative Examples 1-5]
Developer carriers S1 to S5 were produced in the same manner as the developer carrier T1 of Example 1, except that the configuration of the developer carrier was changed as shown in Table 7. In Comparative Examples 1 to 5, the obtained developer carriers S1 to S5 were evaluated by the same method as in Example 1 using Developer Z-1. The obtained evaluation results are shown in Tables 9 and 12.

Example 20
As in Example 1, a coating material having a solid content of 33% by mass shown in Table 7 was used, and grinding was performed with an outer diameter of 20 mmφ (diameter) with an upper and lower end masked as the base and an arithmetic average roughness Ra of 0.2 μm. A processed aluminum cylindrical tube was prepared. The substrate was erected vertically and rotated at a constant speed, and the paint was applied while lowering the spray gun from the upper end of the substrate at a constant speed. Subsequently, a developer carrier T20 was produced by heating and drying the coating layer in a hot air drying furnace at a temperature of 150 ° C. for 30 minutes.

  The layer thickness of the surface layer of the developer carrier T20 was 17 μm, and the surface roughness Ra was 0.87 μm. Table 7 shows the additive materials and physical properties of the surface layer of the developer carrier T20.

<Evaluation 2>
For the evaluation, an electrophotographic image forming apparatus (trade name: iR1750, manufactured by Canon Inc.) was used. The electrophotographic image forming apparatus includes the non-contact type developing apparatus using the magnetic one-component developer shown in FIG. That is, the developing device includes a magnetic one-component developer and a magnetic blade as a developer layer thickness regulating member.

  Evaluation was performed by replacing the developer carrier and the toner provided in the electrophotographic image forming apparatus with the developer carrier T20 and the developer Z-2, respectively.

  Note that printing was performed in the same environment as in the above <Evaluation 1>. Further, the test chart having a printing ratio of 1.5% similar to the above <Evaluation 1> was also used for the image sample for printing. The image evaluation was performed after printing 10 sheets (initial) and after printing 1 million sheets (after durability).

  About the evaluation method, it evaluated by the method similar to Example 1 except that the number of printed sheets of a durability test differs. The obtained evaluation results are shown in Tables 8 and 11.

  Example 20 gave good results as shown in Tables 8 and 11.

Example 21
As in Example 1, a coating material having a solid content of 33% by mass shown in Table 7 was used, and grinding was performed with an outer diameter of 20 mmφ (diameter) with an upper and lower end masked as the base and an arithmetic average roughness Ra of 0.2 μm. A processed aluminum cylindrical tube was prepared. The substrate was erected vertically and rotated at a constant speed, and the paint was applied while lowering the spray gun from the upper end of the substrate at a constant speed. Subsequently, a developer carrier T21 was produced by heating and drying the coating layer in a hot air drying oven at a temperature of 150 ° C. for 30 minutes.

  The layer thickness of the surface layer of the developer carrier T21 was 17 μm, and the surface roughness Ra was 2.03 μm. Table 7 shows the additive materials and physical properties of the surface layer of the developer carrier T21.

<Evaluation 3>
For the evaluation, an electrophotographic image forming apparatus (trade name: iRC4580, manufactured by Canon Inc.) was used. The electrophotographic image forming apparatus includes the developing device using the nonmagnetic two-component developer shown in FIG.

  The cyan developing device provided in the electrophotographic image forming apparatus was removed. Then, a magnet roller and a flange were mounted on the developer carrier T21 and incorporated in the cyan developer. As the developer, a two-component developer in which 92 parts by mass of magnetic carrier 1 and 8 parts by mass of developer Z-3 were mixed by a V-type mixer was used. This developer was installed at the position of the cyan developer unit of iRC4580, and evaluation was performed by forming an image with a single cyan color.

  Note that printing was performed in the same environment as in the above <Evaluation 1>. Further, the test chart having a printing ratio of 1.5% similar to the above <Evaluation 1> was also used for the image sample for printing. The evaluation was performed after printing 10 sheets (initial) and after printing 1 million sheets (after durability).

  About the evaluation method, it evaluated by the method similar to Example 1 except that the number of printed sheets of a durability test differs. The obtained evaluation results are shown in Tables 8 and 11.

  Example 21 gave good results as shown in Tables 8 and 11.

  From the comparison of the sleeve ghost evaluation results shown in Tables 8 to 9 and the developer triboelectric charge amounts shown in Tables 10 to 12 obtained in Examples 1 to 21 and Comparative Examples 1 to 5, the sleeve ghosts were obtained. Is presumed to occur in the cases [1] and [2] below.

  [1] The absolute value of the triboelectric charge amount Q / M of the developer on the developer carrying member is large, that is, the developer is overcharged.

  [2] The difference in the triboelectric charge amount of the developer on the developer carrying member during full black printing and full white printing is large, and / or the friction between the developer on the developer carrying member and the photosensitive member. The charge amount difference is large, that is, the developer charge amount distribution is broad.

  Further, the blotch is presumed to occur when the absolute value of the triboelectric charge quantity Q / M of the developer on the developer carrying member is large, that is, when the developer is overcharged.

  From the above results, it has been found that the present invention can provide a developer carrying member capable of appropriately maintaining the triboelectric charge from the surface layer to the developer.

501 Electrostatic latent image carrier (photosensitive drum)
502 Developer layer thickness regulating member (magnetic blade)
503 Development container 504 Partition member 505 Agitating and conveying member 506 Base 507 Surface layer 508 Developer carrier (developing sleeve)
509 Magnet (Magnet Roller)
511 Agitating and conveying member 512 Developer supply member 513 Development bias power source 514 First chamber 515 Second chamber 516 Developer layer thickness regulating member (elastic blade)
N1, N2, N3, S1, S2 Magnetic pole A Development sleeve rotation direction B Electrostatic latent image carrier (photosensitive drum) rotation direction C Development area

Claims (6)

A developer carrier having a substrate and a surface layer,
The surface layer is
i) a resin having at least one structure selected from the group consisting of —NH ₂ group, ═NH group and —NH— bond in the molecular structure;
ii) quaternary phosphonium salts or quaternary ammonium salts,
iii) a metal compound of an aromatic oxycarboxylic acid, and
iv) conductive particles,
A developer carrying member, which is a cured product of a resin composition comprising:   2. The developer carrying member according to claim 1, wherein the metal in the metal compound of the aromatic oxycarboxylic acid is any metal selected from the group consisting of Al, Cr, Zn, and Zr. The developer carrying member according to claim 1 or 2, wherein the quaternary phosphonium salt has a structure represented by the following formula (1).

(1)
(In formula (1), Z _{1 to} Z ₄ are each independently an alkyl group having 1 to 18 carbon atoms which may have a substituent, a phenyl group which may have a substituent, or a substituent. Represents a naphthyl group that may have a substituent, or a benzyl group that may have a substituent, and Q ⁻ represents a halogen ion, OH ^−, or an organic acid ion. The developer carrying member according to any one of claims 1 to 3, wherein the quaternary ammonium salt has a structure represented by the following formula (2).

(2)
(In the formula (2), R ₁ to R ₄ are each independently, 1 or more carbon atoms which may have a substituent group 18 an alkyl group, an optionally substituted phenyl group, the substituent Represents a naphthyl group that may have a substituent, or a benzyl group that may have a substituent, and X ⁻ represents a halogen ion, OH ^−, or an organic acid ion. Negatively chargeable developer,
A developer container containing the negatively chargeable developer;
A developer carrier that is rotatably held to carry and convey the negatively charged developer supplied from the developer container on the surface; and
A developing device comprising at least a developer layer thickness regulating member for regulating the layer thickness of the negatively chargeable developer layer formed on the developer carrying member,
The developing device according to claim 1, wherein the developer carrying member is the developer carrying member according to claim 1. A method for producing a developer carrier having a substrate and a surface layer,
(I) on the surface of the substrate,
i) a resin having at least one structure selected from the group consisting of —NH ₂ group, ═NH group and —NH— bond in the molecular structure;
ii) quaternary phosphonium salts or quaternary ammonium salts,
iii) a metal compound of an aromatic oxycarboxylic acid, and
iv) conductive particles,
Applying a paint having a resin composition comprising: forming a coating film having the resin composition on the surface of the substrate;
(II) curing the coating film to form the surface layer;
A method for producing a developer carrying member, comprising: