JP2009211002A - Developer carrier and developing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developer carrier that prevents an excessive amount of toner in a toner layer formed on the developer carrier even if the developer carrier is new, and can ensure stable charging of toner for a long time. <P>SOLUTION: The developer carrier has a substrate, and a conductive resin coating layer formed on the substrate. The conductive resin coating layer is formed from a mixture of quaternary ammonium salt containing a sulfur atom in its molecule, quaternary ammonium salt containing molybdenum atom in its molecule, and a binding resin. The developer carrier has a specific relation between the proportion of the sulfur atoms and the molybdenum atoms present in the surface of the conductive resin coating layer measured by X-ray photoelectron spectroscopic analysis and the proportion of the sulfur atoms and the molybdenum atoms present at a depth of 2 μm from the surface. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a developer carrier used in a developing device for developing and developing a latent image formed on an image carrier such as an electrophotographic photosensitive member or an electrostatic recording derivative, and the same. The present invention relates to a developing device.

In an electrophotographic apparatus aiming at light weight and downsizing, a one-component developing type developing apparatus is used. A developing device using a one-component developing system includes a container for storing a developer (toner), a developer carrier (developing sleeve) that is provided so as to close an opening of the container, and transports the developer. A developer regulating member (developing blade) or the like that forms toner on the carrier with a constant thickness is provided. In such a developing device, an electrophotographic image is formed through the following steps.
1) A step of applying positive or negative charge to the toner by friction between the developing sleeve and / or the developing blade and the toner;
2) Apply a small amount of toner on the developing sleeve, and by rotating the developing sleeve, the toner is transported to the developing area where the photosensitive member (photosensitive drum) on which the electrostatic latent image is formed and the developing sleeve face each other. The step of:
3) A step of developing the toner by flying the toner onto the electrostatic latent image on the surface of the photosensitive drum, causing the toner to develop, and developing the electrostatic latent image as a toner image.

  By the way, in order to meet the demand for higher image quality of electrophotographic images, the toner is becoming smaller in particle size and finer. Such a small particle size toner has a large surface area per unit mass. Therefore, the surface charge of the toner tends to increase during the development process. On the other hand, spherical toner is used to keep toner consumption low. Such a toner has a smooth surface as compared with a pulverized toner, and contains a magnetic substance, so that it is excessively charged or the amount of charge tends to become unstable. As a result, image defects such as sleeve ghost and density unevenness tend to occur. This tendency is particularly remarkable at the initial stage of use of a new developing device.

In response to such a tendency, the developing sleeve is provided with a conductive coating layer containing a quaternary ammonium salt compound that is positively charged with respect to iron powder, and is applied to a spherical toner or a negative toner manufactured by a polymerization method. On the other hand, a method for preventing excessive charging such as charge-up has been reported. (Patent Documents 1 and 2). By using such a developing sleeve, suppression of charge-up and stable improvement of charge application to the toner are recognized. However, improvement is demanded for image defects that are likely to occur in the initial stage of use of a new developing device.
JP 2003-57951 A JP 2002-311636 A

  An object of the present invention is to suppress an excessive amount of toner in a toner layer formed on a developer carrier even if it is a new developer carrier, and to stably charge the toner over a long period of time. It is an object of the present invention to provide a developer carrier that can be applied. In particular, even when a spherical toner obtained by a polymerization method or a toner having a high charge amount such as a low magnetic force toner is used, a constant amount of toner layer can be formed on the developer carrying member, and the toner can be charged. An object of the present invention is to provide a developer carrying member that can be controlled well. A developing device that can suppress image density unevenness, sleeve ghost, blotch, and the like due to excess toner supplied by the developer carrying member, can continuously obtain the effect, and has excellent durability. It is to provide.

The developer carrier according to the present invention is a developer carrier having a substrate and a conductive resin coating layer formed on the substrate, and the conductive resin coating layer contains a sulfur atom in the molecule. X-ray photoelectron spectroscopic analysis containing sulfur atoms and molybdenum atoms by being formed from a mixture containing a quaternary ammonium salt, a quaternary ammonium salt containing molybdenum atoms in the molecule, and a binder resin. The sulfur atom abundance rate on the surface of the conductive resin coating layer and the molybdenum atom abundance rate M0 (atom%) measured by the above are set to a depth of 2 μm from the surface of the conductive resin coating layer. When the sulfur atom abundance is S2 (atomic%), the molybdenum atom abundance is M2 (atomic%), the ratio of S2 to S0 is SX, and the ratio of M2 to M0 is MX. The following formulas (A) to (O And satisfies the:
(A) 0.100 ≦ S0 ≦ 1.500
(A) 0.050 ≦ M0 ≦ 1.000
(U) 0.500 ≦ SX
(D) MX ≦ 0.700
(E) 1.200 ≦ SX / MX ≦ 2.000.

  The developing device according to the present invention includes a container for storing a developer, the developer carrier, and a developer regulating member that makes the thickness of the developer formed on the surface of the developer carrier constant. It is characterized by having.

  According to the developer carrying member of the present invention, even if it is a new developer carrying member, the toner amount in the toner layer formed on the developer carrying member is suppressed from being excessive and stable with respect to the toner. Charge can be imparted over a long period of time. In particular, even when a spherical toner obtained by a polymerization method or a toner having a high charge amount such as a low magnetic force toner is used, a constant amount of toner layer can be formed on the developer carrying member, and the toner can be charged. It can be controlled well. According to the developing device of the present invention, image density unevenness, sleeve ghost, blotch, and the like caused by excess toner supplied by the developer carrying member can be suppressed, and the effects can be continuously obtained. And excellent durability.

  The developer carrier of the present invention has a substrate and a conductive resin coating layer formed on the substrate.

[Substrate]
The substrate in the development carrier of the present invention has conductivity, supports the upper conductive resin coating layer, and has strength as a developer carrier. Examples of the shape of the substrate include a cylindrical shape, a columnar shape, and a belt shape. When a non-contact developing method is used for the photosensitive drum, a cylindrical shape or a columnar shape is preferably used. Examples of the material of such a base include nonmagnetic metals or alloys such as aluminum, stainless steel, and brass, and aluminum is preferable from the viewpoint of material cost and ease of processing. The substrate is preferably molded or processed with high accuracy by polishing, grinding, etc. in order to achieve image uniformity. Specifically, the straightness in the longitudinal direction is preferably 30 μm or less, more preferably 20 μm or less, More preferably, it is 10 μm or less.

  When the developer carrier is cylindrical or columnar, the fluctuation of the gap with the photoconductor is specifically measured by abutting the vertical surface with a uniform spacer and rotating the developer carrier. It is preferable that the fluctuation of the gap with the vertical plane is 30 μm or less. More preferably, it is 20 micrometers or less, More preferably, it is 10 micrometers or less.

  When a developing method in which the photosensitive drum is brought into direct contact is used, a cylindrical substrate having a coating layer containing a rubber or elastomer such as urethane, EPDM, or silicone on a cylindrical metal core is preferably used. When a developing method using a magnetic developer is used, a substrate such as a magnet roller in which a magnet is disposed in a cylindrical metal core in order to magnetically attract and hold the developer on the developer carrier. Can be used.

[Conductive resin coating layer]
The conductive resin coating layer includes at least one quaternary ammonium salt containing a sulfur atom in the molecule, a quaternary ammonium salt containing a molybdenum atom in the molecule, and an amino group and an imino group in the molecule. And a binder resin having a group. Therefore, the conductive resin coating layer contains sulfur atoms and molybdenum atoms. In the present specification, hereinafter, a quaternary ammonium salt containing a sulfur atom in the molecule is also referred to as a “sulfur-containing quaternary ammonium salt”. Similarly, a quaternary ammonium salt containing a molybdenum atom in the molecule is also referred to as “molybdenum-containing quaternary ammonium salt”.

And the abundance of sulfur atoms on the surface of the conductive resin coating layer measured by X-ray photoelectron spectroscopy is S0 (atomic%), the abundance of molybdenum atoms is M0 (atomic%),
The sulfur atom abundance at a depth of 2 μm from the surface of the conductive resin coating layer measured by X-ray photoelectron spectroscopy is S2 (atomic%), and the molybdenum atom abundance is M2 (atomic%).
When the value of the ratio of S2 to S0 is SX and the value of the ratio of M2 to M0 is MX,
The following formulas (a) to (e) are satisfied.
(A) 0.100 ≦ S0 ≦ 1.500
(A) 0.050 ≦ M0 ≦ 1.000
(U) 0.500 ≦ SX
(D) MX ≦ 0.700
(E) 1.200 ≦ SX / MX ≦ 2.000.

The technical significance of the above formulas (a) to (e) will be described below.
(A) 0.100 ≦ S0 ≦ 1.500
(A) 0.050 ≦ M0 ≦ 1.000
In the above formulas (a) and (b), S0 (atomic%) represents the abundance of sulfur atoms on the surface of the conductive resin coating layer measured by X-ray photoelectron spectroscopy. M0 (atomic%) represents the abundance of molybdenum atoms on the surface of the conductive resin coating layer measured by X-ray photoelectron spectroscopy. By setting the abundance ratio (S0) of sulfur atoms on the surface of the conductive resin coating layer to 0.100 atomic% or more and the abundance ratio (M0) of molybdenum atoms to 0.050 atomic% or more, the initial stage of the developer carrier It is possible to suppress an excessive increase in charge imparting ability for the toner during use. And even in a low-humidity environment, it is possible to suppress a decrease in developability accompanying charge-up.

  On the other hand, by setting S0 to 1.500 atomic% or less and M0 to 1.000 atomic% or less, it is possible to suppress insufficient charging of the toner in the initial use of the developer carrier, and particularly high humidity. It is possible to suppress deterioration in developability such as low density under the environment.

In the following formulas (c) and (d), S2 (atomic%) represents the abundance of sulfur atoms at a depth of 2 μm from the surface of the conductive resin coating layer measured by X-ray photoelectron spectroscopy. M2 (atomic%) represents the abundance of the molybdenum atoms in the conductive resin coating layer measured by X-ray photoelectron spectroscopy. SX represents the value of the ratio of S2 to S0 (S2 / S0). MX represents the value of the ratio of M2 to M0 (M2 / M0).
(C) 0.500 ≦ SX
(D) MX ≦ 0.700
SX is the ratio of the sulfur atom abundance (S2) at a depth of 2 μm from the surface to the sulfur atom abundance (S0) on the surface of the conductive resin coating layer. On the other hand, it is a value relatively representing how much exists at a depth of 2 μm. The closer this value is to 1, the more uniformly it exists in the depth direction in the conductive resin coating layer. If SX is 0.500 or more, the effect of the sulfur-containing quaternary ammonium salt can prevent the toner from being overcharged, and development associated with charge-up even in a low humidity environment. The occurrence of a decrease in sex can be suppressed. In order to exert the charge control effect of the sulfur-containing quaternary ammonium salt in long-term use, SX is preferably 1.5 or less.

  On the other hand, MX is the value of the ratio of molybdenum atom abundance (M2) at a depth of 2 μm from the surface to the molybdenum atom abundance (M0) on the surface of the conductive resin coating layer. If this value is 0.700 or less, the abundance of the surface of the molybdenum-containing quaternary ammonium salt is relatively increased. For this reason, it is possible to obtain an effect of suppressing excessive charging of toner when forming an electrophotographic image using a new developer bearing member, and to suppress density unevenness due to ghosting or uneven charging, etc. An image can be obtained.

Furthermore, the relative ratio SX / MX of localization of sulfur atoms and molybdenum atoms to the surface of the conductive resin coating layer satisfies the formula (e).
(E) 1.200 ≦ SX / MX ≦ 2,000.

  The larger SX / MX, the higher the abundance of molybdenum atoms on the surface of the conductive resin coating layer compared to sulfur atoms. If SX / MX is 1.200 or more, the proportion of the molybdenum-containing quaternary ammonium salt localized on the surface side of the conductive resin coating layer increases, and the developer carrier is overcharged even in the initial use. Adhesion of toner fine powder and free external additives to the surface of the conductive resin coating layer can be suppressed. For this reason, it is possible to suppress initial ghosts and uneven density due to non-uniform charging of toner. Moreover, if SX / MX is 2.000 or less, it can suppress that molybdenum containing quaternary ammonium salt exists excessively in the conductive resin coating layer surface vicinity. For this reason, it is possible to sufficiently charge the toner, and it is possible to suppress a decrease in developability such as a low density in a high humidity environment.

  In the conductive resin coating layer, sulfur atoms exist relatively uniformly between the surface and 2 μm below the surface, and molybdenum atoms are unevenly distributed on the surface, so that even when a new developer carrier is used, it is excessive for the toner. The reason for the effect of suppressing the static charge is not clear. The reason for this is considered as follows. The sulfur-containing quaternary ammonium salt and the molybdenum-containing quaternary ammonium salt are uniformly dispersed in the binder resin containing at least one of an amino group or an imino group in the mixture, and further, a conductive resin coating layer is formed. When forming, it is taken into the structure of the binder resin. Then, the charged polarity of counter ions of ammonium ions is developed in the conductive resin coating layer, and as a result, the conductive resin coating layer containing the ammonium salt is considered to have negative chargeability.

  Here, although the sulfur-containing quaternary ammonium salt can maintain the above-described effects over a long period of time, it has a tendency to exist uniformly in the conductive resin coating layer, and is effective in the initial use. In order to achieve this, a large amount of addition tends to be required. Molybdenum-containing quaternary ammonium salts have high surface orientation, and have a suitable effect of controlling the surface conductivity of the conductive resin coating layer with a small amount of addition and suppressing excessive charging of the toner. By using the molybdenum-containing quaternary ammonium salt, it is considered that the excessive charging of the toner can be effectively suppressed even when an electrophotographic image is formed using a new electrophotographic process cartridge.

  As the abundance ratio of sulfur atoms and molybdenum atoms measured by X-ray photoelectron spectroscopic analysis at the surface of the conductive resin coating layer and 2 μm below the surface, values obtained by the following measuring methods can be adopted.

The measurement of each atomic ratio on the surface is as follows.
X-ray photoelectron spectroscopic analysis is performed under the following conditions using Quantum 2000 of ULVAC-PHI Co., Ltd.
X-ray source; Monochrome Al Kα
Xray Setting; 100 μmφ (100 W (20 KV))
Photoelectron take-off angle: 45 ° Neutralization condition: Combined analysis region of neutralization gun and ion gun: 300 × 1500 μm
Pass Energy: 11.75 eV
Step size: 0.05eV
Here, the quantitative analysis of each atom uses the following peak to determine the atomic concentration (atomic%).
C 1s (Bonding Energy: 280 eV to 295 eV),
N 1s (Bonding Energy: 395 eV to 410 eV),
O 1s (Bonding Energy: 525 eV to 540 eV),
S 2p (Bonding Energy: 160 eV to 175 eV) and Fe 2p3 (Bonding Energy: 706 eV to 730 eV).

  Measurement at a depth of 2 μm below the surface of the conductive resin coating layer was carried out by scraping the surface of the developer carrying member by 0.1 μm using a microtome in an environment of a temperature of 23 ° C. and a relative humidity of 60% RH. Same as surface measurement.

  As described above, in the conductive resin coating layer according to the present invention, molybdenum atoms derived from the quaternary ammonium salt are localized on the surface. Accordingly, when an electrophotographic image is formed using a new electrophotographic process cartridge, it is possible to suppress adhesion of overcharged toner fine powder and free external additive to the surface of the conductive resin coating layer. As a result, toner charging unevenness and local charge-up can be suppressed, and image defects such as halftone density unevenness, blotch, and ghost caused by these can be remarkably suppressed.

  Moreover, in the conductive resin coating layer which concerns on this invention, the sulfur atom originating in a quaternary ammonium salt compound will exist uniformly in the depth direction in a conductive resin coating layer. As a result, it is possible to maintain an appropriate charge imparting ability even when the durability is advanced, and to suppress a charge-up after durability in a low-humidity environment and a decrease in developability due to blotch.

  As a sulfur containing quaternary ammonium salt contained in the mixture which forms the said conductive resin coating layer, the compound represented by Formula (1) can be mentioned.

In the formula (1), R1 to R4 independently represent an alkyl group which may have a substituent or an aryl group which may have a substituent, and X ⁻ represents an acid ion containing a sulfur atom. . These alkyl groups may be linear or cyclic, and preferably have 1 to 12 carbon atoms. As the aryl group, those having 6 to 9 carbon atoms are preferable. Specific examples of the aryl group include a phenyl group, a benzyl group, a tolyl group, and a xylyl group. In addition, examples of the substituent for these groups include linear, branched, and cyclic alkyl groups. Examples of the acid ion containing a sulfur atom represented by X ⁻ include organic sulfate ions and organic sulfonate ions. Among these, those containing a sulfonate group are particularly preferred.

As a molybdenum containing quaternary ammonium salt, the compound in which X < ^- > in Formula (1) represents the acid ion containing a molybdenum atom can be mentioned. Examples of the acid ion containing a molybdenum atom represented by X ⁻ include a molybdate ion, a heteropolyacid ion containing a molybdenum atom, etc. Among these, an ion containing a molybdate ion is particularly preferable.

  Preferred specific examples of the sulfur-containing quaternary ammonium salt are shown in Tables 1-1 and 1-2, and preferred specific examples of the molybdenum-containing quaternary ammonium salt are shown in Table 1-3.

  The binder resin contained in the mixture preferably has at least one group selected from an amino group and an imino group in the molecule. The imino group may be either ═NH or —NH—. The conductive resin coating layer containing a binder resin having an amino group or an imino group acts to suppress excessive charging of the developer, and can control the application of frictional charge to the developer. This prevents the developer from being charged up on the developer carrying member, and can maintain the high charging stability of the developer even in a new developer carrying member or even at low temperature and low humidity. And a high-definition image having long-term stability can be provided.

  As the binder resin, a phenol resin or a polyamide resin synthesized using a nitrogen-containing compound such as ammonia as a catalyst, an epoxy resin or a urethane resin using polyamide as a curing agent, and a copolymer thereof may be used. it can. The phenol resin may be synthesized using any acidic or basic nitrogen-containing compound as a catalyst. Examples of the acidic nitrogen-containing compound catalyst include ammonium salts such as ammonium sulfate, ammonium phosphate, ammonium sulfamate, ammonium carbonate, ammonium acetate, and ammonium maleate, or amine salts. Examples of the basic nitrogen-containing compound catalyst include the following. ammonia. Dimethylamine, diethylamine, diisopropylamine, diisobutylamine, diamylamine, trimethylamine, triethylamine, tri-n-butylamine, triamylamine, dimethylbenzylamine, diethylbenzylamine, dimethylaniline. Diethylaniline, N, N-di-n-butylaniline, N, N-diamilaniline, N, N-di-t-amylaniline, N-methylethanolamine, N-ethylethanolamine, diethanolamine, triethanolamine, dimethyl Ethanolamine. Amino compounds such as diethylethanolamine, ethyldiethanolamine, n-butyldiethanolamine, di-n-butylethanolamine, triisopropanolamine, ethylenediamine, hexamethylenetetramine; Pyridine such as pyridine, α-picoline, β-picoline, γ-picoline, 2,4-lutidine, 2,6-lutidine, and derivatives thereof. Imidazoles such as quinoline compounds, imidazole, 2-methylimidazole, 2,4-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, and 2-heptadecylimidazole. These derivatives.

Specific examples of the polyamide resin are listed below.
Nylon 6, 66, 610, 11, 12, 9, 13, Q2 nylon and the like, nylon copolymers based on these, N-alkyl-modified nylon, N-alkoxylalkyl-modified nylon and the like.
Resins containing polyamide resin components such as various resins modified with polyamide, such as polyamide-modified phenolic resin, or epoxy resin using polyamide resin as a curing agent.

  As the urethane resin, any resin containing a urethane bond can be used, and one having a urethane bond formed by a polymerization addition reaction between polyisocyanate and polyol can be used.

Specific examples of the polyisocyanate forming the urethane resin include the following.
As aromatic polyisocyanates, TDI (tolylene diisocyanate), pure MDI (diphenylmethane diisocyanate), polymeric MDI (polymethylene polyphenyl polyisocyanate), and TODI (tolidine diisocyanate). NDI (naphthalene diisocyanate) and the like.
As aliphatic polyisocyanates, HMDI (hexamethylene diisocyanate), IPDI (isophorone diisocyanate), XDI (xylylene diisocyanate), hydrogenated XDI (hydrogenated xylylene diisocyanate). Hydrogenated MDI (dicyclohexylmethane diisocyanate).

Specific examples of the polyol include the following.
Examples of polyether polyols include PPG (polyoxypropylene glycol), polymer polyol, polytetramethylene glycol (PTMG), and the like.
Examples of polyester polyols include adipate, polycaprolactone, and polycarbonate polyol.
Examples of the polyether-based modified polyol include PHD polyol and polyether ester polyol.
In addition, epoxy-modified polyol, ethylene-vinyl acetate copolymer partially saponified polyol (saponified EVA), flame retardant polyol.

  As a content rate of the sulfur containing quaternary ammonium salt in the said mixture, 5 mass parts-60 mass parts are preferable with respect to 100 mass parts of binder resin. As a content rate of a molybdenum containing quaternary ammonium salt, 3 mass parts-25 mass parts are preferable with respect to 100 mass parts of binder resin. By setting it as such a content ratio, a sulfur atom and a molybdenum atom can be contained in the conductive resin coating layer with the above-mentioned abundance.

  Further, the mixture can contain conductive fine particles, roughened particles, lubricant, charge control agent, etc., which may be contained in the conductive resin coating layer as long as the functions of the substances are not impaired.

The conductive fine particles adjust the volume resistance value of the conductive resin coating layer, and the developer is fixed on the developer carrier by charge-up or developed by the developer carrier resulting from the charge-up of the developer. It is used to suppress poor frictional charge application to the agent. The conductive fine particles have a content in the conductive resin coating layer such that the volume resistance value of the conductive resin coating layer is 10 ⁴ Ω · cm or less, more preferably 10 ³ Ω · cm or less. Select and use.

  For measuring the volume resistance of the conductive resin coating layer, a 10 μm to 20 μm coating layer was formed on a 100 μm thick polyethylene terephthalate (PET) sheet, and a resistivity meter Loresta AP (manufactured by Mitsubishi Chemical Corporation) was used. The volume resistance value is measured using a four-terminal probe. The measurement environment is a temperature of 20 to 25 ° C. and a humidity of 50 to 60% RH.

Any material may be used for the conductive fine particles, but specific examples include the following.
Fine metal powder (aluminum, copper, nickel, silver, etc.);
Conductive metal oxides (antimony oxide, indium oxide, tin oxide, titanium oxide, zinc oxide, molybdenum oxide, potassium titanate, etc.);
Crystalline graphite;
Various carbon fibers;
Carbon black (furnace black, lamp black, thermal black, acetylene black, channel black, etc.);
Metal fiber.

  Among these conductive particles, carbon black, in particular amorphous carbon, has excellent electrical conductivity, and it can be filled with a polymer material to impart electrical conductivity, and an arbitrary conductivity can be obtained simply by controlling the amount added. This is preferable. In addition, when prepared into a paint, the thixotropic effect also improves the dispersion stability and coating stability. 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 this range, it is possible to suppress a decrease in strength (wearability) of the conductive resin coating layer, and to reduce the resistance value of the conductive resin coating layer to a desired level. The occurrence of toner sticking can be suppressed.

  In order to make the surface roughness of the conductive resin coating layer uniform and to maintain an appropriate surface roughness, the roughening particles can obtain more preferable results by adding roughening particles for forming irregularities. . The rough particles are preferably substantially spherical. When the roughened particles are spherical, a desired surface roughness can be obtained with a smaller addition amount than that of the irregular shaped particles, and a surface on which irregularities are uniformly formed can be obtained. Further, even when the surface of the conductive resin coating layer is worn, the change in the surface roughness is small, and the variation in the thickness of the toner layer formed on the developer carrier can be suppressed. For this reason, the toner can be charged uniformly, the surface of the developer carrying member can be prevented from being contaminated with toner and the occurrence of fusion, and sleeve ghosts, streaks, and unevenness can be generated in the obtained image. Can be suppressed. The volume average particle diameter of the spherical particles as the roughening particles is preferably 0.3 μm to 30 μm. If it has a volume average particle diameter in this range, the surface of the conductive resin coating layer can be formed with an appropriate surface roughness, and the above-described effects can be obtained more remarkably. Further, it is possible to suppress a decrease in mechanical strength, and it is possible to suppress the occurrence of white spots and black spots due to image streaks due to a large surface roughness and bias leak.

Here, the spherical particles refer to particles having a major axis / minor axis ratio of about 1.0 to 1.5, and the ratio of major axis / minor axis is preferably 1.0 to 1.2, more preferably. Is spherical. The true density of the spherical particles is preferably ³ g / cm ³ or less. When the true density is 3 g / cm ³ or less, an appropriate surface roughness can be imparted to the surface of the conductive resin layer without using a large amount of particles. Further, it is possible to suppress an increase in the difference from the density of the binder resin, improve the dispersibility of the spherical particles in the binder resin, and form the surface of the conductive resin coating layer with a uniform roughness. .

  The ratio of major axis / minor axis is obtained by taking an electron micrograph of the surface of a sample prepared under the same conditions as the conductive resin coating layer, and measuring the major axis length A (μm) and the minor axis length from the electron micrograph. The thickness B (μm) is measured, and the major axis / minor axis C = A / B is calculated. This measurement is performed 20 times, and the ratio of particle major axis / minor axis can be obtained with a 50% value.

  Moreover, the measured value measured using the dry-type density meter Accupic 1330 (made by Shimadzu Corporation) can be employ | adopted for the true density of uneven | corrugated formation particle | grains.

Furthermore, it is preferable that the roughened particles have conductivity. By making the rough particles conductive, it is possible to suppress the accumulation of charge on the surface, and to prevent the toner from roughing and adhering to the particles. Can be suppressed. For this reason, it is possible to obtain the effect of further improving the chargeability of the toner and further improving the developability. The conductivity of the rough particles is preferably 10 ⁶ Ω · cm or less, more preferably 10 ⁶ Ω · cm to 10 ⁻³ Ω · cm. Since the rough particles have conductivity in this range, even if the rough particles are exposed on the surface due to wear of the conductive resin coating layer, the toner to the developer carrier is obtained using the rough particles as a core. The effect of suppressing contamination and fusion can be fully enjoyed.

  The content of the roughened particles in the conductive resin coating layer can be in the range of, for example, 1 part by mass to 50 parts by mass with respect to 100 parts by mass of the binder resin.

  The lubricant that may be contained in the mixture can increase the lubricity of the surface of the conductive resin coating layer and improve the durability of the conductive resin coating layer. A lubricant that is solid at room temperature is preferable because it can suppress exudation from the conductive resin coating layer. Specific examples of such a solid lubricant include crystalline graphite, molybdenum disulfide, boron nitride, mica, graphite fluoride, silver-niobium selenide, calcium chloride-graphite, talc, and zinc stearate. Can be mentioned. Of these, crystalline graphite is preferable because it does not impair the conductivity of the conductive resin coating layer even when used in combination with roughened particles. In particular, graphitized particles having a graphitization degree p (002) of 0.20 to 0.95 as a conductive substance described in JP-A No. 2003-323041 are the coating strength of the conductive resin coating layer. It is preferable because the surface lubricity can be improved. The solid lubricant preferably has a volume average particle size of 0.2 μm to 20 μm, more preferably 1 μm to 15 μm. If the volume average particle diameter of the solid lubricant is in the above range, sufficient lubricity can be obtained and a conductive resin coating layer having a uniform surface can be obtained.

  The addition amount of the solid lubricant is preferably in the range of 1 part by mass to 100 parts by mass with respect to 100 parts by mass of the binder resin. By containing the solid lubricant in this range, it is possible to suppress the developer from adhering to the surface of the conductive resin coating layer. Moreover, the fall of the intensity | strength (wear resistance) of a conductive resin coating layer can be suppressed.

  The charge control agent that may be contained in the mixture imparts more uniform conductivity to the conductive resin coating layer. As the charge control agent, for example, the following can be used. Modified products with nigrosine and fatty acid metal salts. Diorganotin oxide (butyltin oxide, dioctyltin oxide, dicyclohexyltin oxide, etc.). Diorganotin borates (thibutyltin borate, dioctyltin borate, dicyclohexyltin borate). Guanidines. Imidazole compounds.

  The content of the charge control agent is preferably 1 part by mass to 100 parts by mass with respect to 100 parts by mass of the coating resin. If the content of the charge control agent is 1 part by mass or more, the charge control of the conductive resin coating layer is performed. If the content is 100 parts by mass or less, the occurrence of poor dispersion in the conductive resin coating layer is suppressed. A decrease in strength can be suppressed.

[Method of forming conductive resin coating layer]
A method for forming the conductive resin coating layer will be described below. It is possible to employ a method in which the above mixture is appropriately mixed using a dispersion medium, each component is dispersed in the dispersion medium to form a coating liquid, applied onto a substrate, and the coating film is dried, solidified or cured. In order to prepare a coating liquid by dispersing each component, a dispersing device using beads such as a sand mill, a paint shaker, a dyno mill, and a pearl mill can be suitably used. Moreover, as a coating method, methods, such as a dipping method, a spray method, and a roll coat method, can be applied. In particular, the spray method is suitable because it can easily control the existence state of sulfur atoms and molybdenum atoms in the conductive resin coating layer by combining with the solvent species described later.

  The dispersion medium used for the coating liquid is preferably a solvent that dissolves the binder resin. Such a solvent preferably has a boiling point of 80 ° C to 165 ° C, more preferably 100 ° C to 130 ° C. The higher the boiling point of the solvent used, the less the tendency for the sulfur-containing quaternary ammonium salt to localize in the vicinity of the surface of the coating film, especially in the case of sulfur-containing quaternary ammonium salts that are soluble in alcohol and other solvents. Is strong. On the other hand, the molybdenum-containing quaternary ammonium salt has a higher surface orientation as the boiling point of the solvent used increases, and tends to promote localization on the coating film surface. In particular, when a solvent having a boiling point of 100 ° C. to 130 ° C. is used, the tendency to localize on the surface of the coating film is increased. However, when a solvent having a boiling point exceeding 160 ° C. is used, the surface orientation is moderated.

  Moreover, it is preferable that a dispersion medium is contained in 30 mass%-70 mass% in a coating liquid. If the content of the solvent having the boiling point in the coating liquid is 30% by mass or more, the localization of the sulfur-containing quaternary ammonium salt on the surface of the coating film is alleviated, so that the toner is charged. It can suppress that the provision effect reduces. Further, if the content of the dispersion medium having the above boiling point in the coating liquid is 70% by mass or less, localization of molybdenum atoms on the coating film surface is promoted, and a new developer carrier is used. The effect of stabilizing the initial charging of the toner can be obtained.

  Specific examples of the dispersion medium having a boiling point of 80 ° C. or higher include isopropyl alcohol, sec-butyl alcohol, cyclohexane, and toluene. Isopropyl alcohol, sec-butyl alcohol and the like can be preferably used. Specific examples of the dispersion medium having a boiling point of 100 ° C. to 130 ° C. include n-butyl alcohol, isobutyl alcohol, methyl cellosolve, methyl isobutyl ketone, isobutyl acetate, and m-xylene. n-butyl alcohol, isobutyl alcohol and the like can be preferably used.

[Surface roughness of conductive resin coating layer]
The surface roughness of the conductive resin coating layer is preferably arithmetic mean roughness Ra (JIS B0601-2001) of 0.4 μm to 1.5 μm, more preferably 0.5 μm to 1.2 μm. . When the surface roughness is in the above numerical range, the amount of toner on the developer carrying member can be made stable and constant, the toner can be uniformly charged, and the conductive resin coating layer has abrasion resistance. And developer resistance are also excellent.

  As the arithmetic average roughness (Ra) of the surface of the conductive resin coating layer, a measurement value measured as follows can be adopted according to JIS B0601 (2001). Using a surf coder SE-3500 (manufactured by Kosaka Laboratories), measurement is performed under conditions of a cutoff of 0.8 mm, an evaluation length of 4 mm, and a feed rate of 0.5 mm / s. Then, an average value of the measured values of a total of 9 points of 3 points in the axial direction × 3 points in the circumferential direction is defined as Ra.

  Furthermore, the surface roughness of the conductive resin coating layer is preferably expressed as follows. The conductive resin coating layer preferably has the following relationship in the surface shape measured using a focus optical system laser. In the following formula, A represents a constant area of a region where the convex portion is not formed by the rough particles, and B represents a volume of the convex portion due to minute unevenness formed on the surface of the region of the constant area A.

4.5 ≦ B / A ≦ 6.5
B / A represents the degree of fine unevenness formed by particles other than the roughening particles. If B / A is 6.5 or less, the degree of minute unevenness on the surface of the developer carrying member becomes small. Therefore, the uneven shape is also made uniform, and in particular, when an elastic blade is used as a developer regulating member and a spherical toner is used, the toner generated from the uneven portion of the uneven surface formed on the surface of the conductive resin coating layer Can be suppressed. As a result, there is an effect that generation of image streaks and image density unevenness is suppressed. Further, if B / A is 4.5 or more, the surface of the developer carrying member has moderately minute irregularities, the releasability from the toner is improved, and the sleeve ghost and toner contamination due to the charge-up of the toner. Is less likely to occur.

    In order to form a surface satisfying the above relationship on the conductive resin coating layer, a coating prepared by adding particles having a smaller diameter than the rough particles (hereinafter also referred to as “small particle”) to the mixture. It can be formed by adjusting the dispersion state in the liquid, the coating method, and the like. As a method for controlling B / A depending on the dispersion state of the small-diameter particles, there is a method in which the small-diameter particles are dispersed in the conductive resin coating layer so that the volume average particle diameter is 0.5 to 4.0 μm. it can. When the volume average particle diameter of the small-diameter particles is 0.5 μm or more, minute irregularities can be formed on the surface of the conductive resin coating layer by the small-diameter particles, and B / A can be 4.5 or more. . On the other hand, if the volume average particle size is 4.0 μm or less, it is possible to suppress the unevenness imparted to the surface of the conductive resin coating layer by the small particle from being excessively large, and B / A can be made 6.5 or less. . Control of the volume average particle size of the graphitized particles in the conductive resin coating layer is achieved by means of adjusting the particle size distribution by pulverization and classification of the small particle particles used and the dispersion strength of the small particle particles in the conductive resin coating layer. It is possible by adjusting.

  Here, B / A can employ a measurement value obtained by the following measurement method.

  This is performed using an ultra-deep shape measuring microscope (trade name: VK-8500; manufactured by KEYENCE). This device irradiates an object with a laser emitted from a light source, and measures the shape of the object based on objective lens position information that maximizes the amount of reflected light received by the light receiving element at the confocal position. To do.

The measurement conditions are as follows.
Objective lens magnification: 100x Optical zoom magnification: 1x Digital zoom magnification: 1x RUN MODE: Lens movement pitch in the direction of color ultra-deep height: 0.1 μm
Laser gain: 716
Laser offset: -335
Shutter (camera setting): 215
A region of area A (4 × 10 ⁻¹⁰ m ² ) of 20 μm in the horizontal direction and 20 μm in the vertical direction where there is no projection formed by rough particles on the surface of the conductive resin coating layer is appropriately selected and measured.

The measurement result is analyzed by image analysis (software VK-H1W Version 1.07; manufactured by KEYENCE), and correction processing is performed. First, tilt correction processing is performed to correct the overall tilt. The correction target is only height data, and the correction method is an automatic mode of surface correction. Next, in order to remove noise components, smoothing is performed by filtering. The processing conditions are shown below.
Processing size: Number of times of smoothing processing in 3 × 3 area: 1 time File type: simple average Next, after converting the height data obtained by measurement into CSV text data, the conductivity in the entire area to be measured The average height of the surface irregularities was calculated by averaging the height from the bottom of the conductive resin coating layer, and the value was used as the reference plane.

Thereafter, from the surface area / volume measurement mode in the image analysis software VK-H1W, the volume B (m ³ ) of the minute unevenness observed in the range corresponding to the area A of the measurement region was calculated. 20 or more points are measured, the average value B is calculated, and B / A is obtained.

[Thickness of conductive resin coating layer]
The thickness of the conductive resin coating layer is preferably 25 μm or less because a uniform film thickness can be obtained. More preferably, it is 20 micrometers or less, More preferably, it is 4 micrometers-20 micrometers. This thickness varies depending on the material to be used in the conductive resin coating layer can be obtained by the 4000mg / m ² ~20000mg / m ² as a coating mass.

  The thickness of the conductive resin coating layer was measured by taking an electron micrograph of the cross section after cutting the conductive resin coating layer with Micro Gruber MG-1 (trade name; manufactured by NTT Electronics Corporation). The layer thickness is measured in the photomicrograph. Measurement can be performed at 10 locations of the conductive resin coating layer, and the average value can be defined as the layer thickness.

[Developer]
The developing device of the present invention includes a container for storing a developer, the developer carrying member, and a developer regulating member that makes the thickness of the developer formed on the surface of the developer carrying member constant. ing.

  An example of the developing device of the present invention is shown in the schematic block diagram of FIG. The developing device shown in FIG. 1 is a developing device for developing an electrostatic latent image formed and supported on a latent image carrier (photoconductor) 1 by a known process, and a developing sleeve (developer carrier). 8 is provided to face the photoreceptor 1. The developing sleeve has a metal cylindrical tube (base) 6 and a conductive resin coating layer 7 formed thereon. In the hopper (container) 3 in which the magnetic toner 4 of the one-component magnetic developer is accommodated or accommodated, an agitating blade 10 for agitating the magnetic toner is provided. The magnetic toner 4 supplied from the hopper 3 to the developing sleeve 8 is carried on the developing sleeve 8, and the developing sleeve 8 rotates in the arrow A direction so that the developing sleeve 8 and the photosensitive member 1 face each other. It is conveyed to. A magnet 5 for magnetically guiding and holding the magnetic toner 4 on the developing sleeve 8 is disposed in the developing sleeve 8. The magnetic toner 4 obtains a triboelectric charge that enables development of the electrostatic latent image on the photoreceptor 1 by friction with the developing sleeve 8 and / or the layer thickness regulating blade (developer regulating member) 11. In the developing device of the present invention, the thickness of the thin layer of the magnetic toner 4 formed on the developing sleeve 8 by the layer thickness regulating blade 11 is smaller than the minimum gap between the developing sleeve 8 and the photoreceptor 1 in the developing region. Further, it is preferable that the thickness is thinner. The developing device of the present invention is particularly effective for a non-contact type developing device that develops an electrostatic latent image with such a thin magnetic toner layer. A developing bias voltage is applied to the developing sleeve 8 by a power source 9 in order to fly the carried magnetic toner 4. When a DC voltage is used as the developing bias voltage, the developing sleeve 8 is applied to a potential intermediate between the potential of the electrostatic latent image (the region visualized by the adhesion of the magnetic toner 4) and the potential of the background portion. It is preferable. On the other hand, in order to increase the density of the developed image or improve the gradation, an alternating bias voltage may be applied to the developing sleeve 8 to form an oscillating electric field whose direction is alternately reversed in the developing region. In this case, it is preferable to apply to the developing sleeve 8 an alternating bias voltage in which a DC voltage component that can be applied is superimposed on an intermediate potential between the electrostatic latent image potential and the background potential.

  In the developing device, the shape of the hopper, the presence / absence of a stirring blade, the shape of the developer regulating member, the arrangement of the magnetic poles, and the like are not limited thereto.

  In the developing device, as the magnetic toner, a toner charged to a polarity for developing the electrostatic latent image by friction with the developing sleeve is selected and used. In so-called normal development, in which toner is attached to a high potential portion of an electrostatic latent image for visualization, toner charged to a polarity opposite to that of the electrostatic latent image is used. On the other hand, in so-called reversal development in which toner is attached to a low potential portion of an electrostatic latent image for visualization, toner charged with the same polarity as that of the electrostatic latent image is used. Here, the high potential and the low potential are expressed by absolute values.

[Developer]
The developer applied to the developing device can be appropriately selected for its charging polarity by regular development and reversal development as described above. Hereinafter, as an example of a developer suitable for the developing device, a pulverization method, The positively charged toner produced by the polymerization method will be described. The toner by the pulverization method is, for example, a binder resin, a magnetic material, a release agent, a charge control agent, and optionally a component necessary as a magnetic toner such as a colorant and other additives, etc., a mixer such as a Henschel mixer or a ball mill. Mix thoroughly. Subsequently, it is obtained by melt-kneading using a heat kneader such as a heating roller, a kneader, an extruder, etc., cooling and solidifying, pulverizing, classification, and surface treatment as necessary. Either the classification or the surface treatment may be performed first. In the classification step, it is preferable to use a multi-division classifier for improving production efficiency. In the pulverization step, a mechanical impact type or jet type pulverization apparatus can be used. The toner thus obtained is preferably subjected to spheroidizing treatment and surface smoothening treatment by various methods. Compared with pulverized toner particles that are not subjected to this kind of treatment, it is easier to enclose the magnetic material, and the transferability of the developer is improved, and the consumption of the developer can be suppressed by the effect. As a spheroidizing treatment or surface smoothing treatment method, a method using a mechanical force by passing toner through a minute gap between the blade and the liner by means of a device having a stirring blade or blade and a liner or casing or the like is used. Can do.

  In addition, the toner obtained by the polymerization method can be obtained by, for example, suspending and polymerizing a mixture mainly containing a monomer serving as a toner binder resin in water. Specifically, a monomer composition obtained by uniformly dissolving or dispersing a polymerizable monomer, a colorant, a polymerization initiator, and if necessary, a crosslinking agent, a charge control agent, a release agent, and other additives. And Thereafter, the monomer composition is dispersed in an aqueous phase containing a dispersion stabilizer using a stirrer to obtain an appropriate particle size, and a polymerization reaction is performed to obtain a toner having a desired particle size.

  Such toner preferably has an average circularity of 0.970 or more in particles having an equivalent circle diameter of 3 μm or more and 400 μm or less measured by a flow type particle image measuring apparatus. By increasing the average circularity in this way, it becomes easy to triboelectrically charge the surface of individual toner particles, and can be uniformly charged. The toner particles having such a high degree of spheroidization are generally highly charged, and depending on the usage situation, the charge amount may become too high and charge up may occur. However, the developer carrying member of the present invention can impart appropriate charge to the toner particles having a high degree of spheroidization from the initial use to the end of durability.

  A value obtained by the following method can be adopted as the average circularity of the toner particles.

  Measurement is performed in a 23 ° C./60 RH environment using a flow type particle image analyzer FPIA-2100 manufactured by Sysmex Corporation. Measure the particles in the range of the equivalent circle diameter of 0.60 μm to 400 μm, obtain the circularity of the measured particle by the following formula, and further calculate the total circularity in terms of the total number of particles in the equivalent circle diameter of 3 μm to 400 μm. The divided value is defined as the average circularity.

Circularity a = L ₀ / L
In the equation, L ₀ indicates the circumference of a circle having the same projection area as the particle image, and L is the periphery of the particle projection image that has been image-processed with an image processing resolution of 512 × 512 (pixels of 0.3 μm × 0.3 μm). Indicates length.

This circularity is an index of the degree of unevenness of the toner particles, and indicates 1.00 when the toner is a perfect sphere, and the circularity becomes smaller as the surface shape becomes more complicated. As a specific measurement method, 0.5 ml of alkylbenzene sulfonate is added as a dispersant to 250 ml of water from which impurities in the container have been removed in advance, and about 0.5 g of a measurement sample is further added. The suspension in which the sample is dispersed is dispersed for 2 minutes with an ultrasonic transmitter, and the circularity distribution of the particles is measured by setting the dispersion concentration to 20,000 / μl to 10,000,000 / μl. Specifically, the ultrasonic transmitter and conditions are as follows.
UH-150 (manufactured by SMT Corporation)
OUTPUT level: 5
The constant mode sample dispersion is passed through a flow channel (expanding along the flow direction) of a flat and flat flow cell (thickness: about 200 μm). A strobe and a CCD camera are mounted on opposite sides of the flow cell so as to form an optical path that passes across the thickness of the flow cell. While the sample dispersion is flowing through the flow cell, strobe light is irradiated at 1/30 second intervals. As a result, the particles in the sample dispersion are photographed as a two-dimensional image having a certain range parallel to the flow cell. From the area of the two-dimensional image of each particle, the diameter of a circle having the same area is calculated as the equivalent circle diameter. The circularity of each particle is calculated from the projected area of the two-dimensional image of each particle and the perimeter of the projected image using the above circularity calculation formula.

  The toner preferably has a weight average particle diameter of 3 μm to 10 μm in order to develop finer latent image dots faithfully and make it applicable to a high-quality electrophotographic apparatus. If the weight average particle diameter is 3 μm or more, it is possible to suppress a decrease in transfer efficiency and to reduce the residual toner on the photoconductor, and to suppress the photoconductor scraping and toner fusion in the contact charging step. Furthermore, it is possible to suppress an increase in the surface area of the entire toner, to suppress a decrease in fluidity and agitation as a powder, and to uniformly charge each toner particle. An image can be obtained. Further, when the weight average particle diameter of the toner is 10 μm or less, it is possible to obtain a high resolution image in which characters and line images are not scattered.

As the weight average particle diameter of the toner particles, a value obtained by the following measuring method can be adopted. As a measuring device, Coulter Multisizer II (manufactured by Beckman Coulter, Inc.) is used. As the electrolyte, first grade sodium chloride is used to prepare an approximately 1% NaCl aqueous solution. As a measurement method, 0.5 ml of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant to 100 ml of the electrolytic aqueous solution, and 10 mg of a measurement sample is added. The electrolyte solution in which the sample is suspended is subjected to a dispersion process for about 1 minute with an ultrasonic disperser, and the volume distribution is measured by measuring the volume and number of the measurement sample using the 100 μm aperture or the 30 μm aperture as the aperture by the measuring device. And the number distribution. From this result, the weight-based weight average particle diameter (D ₄ ) obtained from the volume distribution (with the median value of each channel as the representative value for each channel) is obtained.

  Hereinafter, the developer carrier and the developing device of the present invention will be described in detail, but the technical scope of the present invention is not limited thereto.

[Example 1]
[Preparation of developer carrier]
A coating solution for the conductive resin coating layer provided on the surface of the developing sleeve was prepared at the following mixing ratio.
Resol type phenolic resin P1 (J325: manufactured by Dainippon Ink & Chemicals, Inc.) (ammonia catalyst used, containing 40% methanol): 250 parts by mass graphitized particles A: 80 parts by mass of conductive carbon black (Conductex 975: Columbia Carbon Co., Ltd.) Manufactured): 20 parts by mass of sulfur-containing quaternary ammonium salt (Exemplary Compound 1): 45 parts by mass of molybdenum-containing quaternary ammonium salt (Exemplary Compound 2-1): 15 parts by mass of conductive spherical particles (Nikabeads PC1020: manufactured by Nippon Carbon Co., Ltd.) ): 12 parts by mass Isobutyl alcohol: 250 parts by mass Methanol: 150 parts by mass.

  As graphitized particles A, mesocarbon microbeads obtained by heat treatment of heavy coal-based oil are washed and dried, then mechanically dispersed in an atomizer mill, and carbonized by primary heat treatment at a temperature of 900 ° C. in a nitrogen atmosphere. I let you. Next, secondary dispersion was performed with an atomizer mill, followed by heat treatment in a nitrogen atmosphere at a temperature of 2800 ° C., followed by classification and use of a volume average particle size of 3.6 μm. The above material was dispersed in a sand mill using glass beads. As a dispersion method, the above methanol, conductive carbon black and crystalline graphite are added to 100 parts by mass of the above-mentioned resol type phenol resin solution, and dispersed for 2 hours in a sand mill using glass beads having a diameter of 1 mm as media particles. Thus, a coating intermediate M1 was obtained. Next, a sand mill using glass beads having a diameter of 2 mm as media particles by adding sulfur-containing quaternary ammonium salt, molybdenum-containing quaternary ammonium salt and conductive spherical particles to the remaining 50 parts by mass of the resol type phenol resin solution. Was dispersed for 30 minutes to obtain paint intermediate J1. The coating intermediate M1, the coating intermediate J1, and ethanol were mixed and stirred to obtain a coating liquid L1.

  Using this coating solution, an aluminum cylindrical tube ground to an outer diameter of 20 mm and centerline average roughness Ra of 0.2 μm is vertically set up, rotated at a constant speed, and masked at the upper and lower ends, and spray gun Was applied while lowering at a constant (50 mm / s) speed. The coating was carried out under the conditions that the temperature was 28 ° C. and the relative humidity was 40%, and the temperature of the coating solution was controlled at 28 ° C. in a thermostatic bath. Subsequently, the coating film of the coating liquid is cured by heating at 150 ° C. for 30 minutes in a hot air drying furnace to form a conductive resin coating layer having a thickness of 10.0 μm. Obtained.

  About the obtained developer carrier, S0, M0, S2, M2, B / A, and surface roughness Ra were measured by the above-mentioned method, and SX and MX were obtained. The results are shown in Table 2.

[Image evaluation]
Furthermore, image formation was performed using the developer carrier S-1 and image evaluation was performed. For the image evaluation, the developer carrier was removed from a new cartridge for a commercially available laser beam printer LesserJet2015 (manufactured by Hewlett Packard), and the developer was removed. Next, a magnet and a flange were attached so that the developer carrier S-1 could be attached to the cartridge, and the developer carrier S-1 was attached to the cartridge, filled with the following developer T-1, and an image was output by a LesserJet 2015 machine. Image output is performed under a low temperature / low humidity environment (L / L) of 15 ° C./10% RH and a high temperature / high humidity environment (H / H) of 30 ° C./85% RH. The fog was evaluated as follows. These results are shown in Table 3.

[toner]
An aqueous solution containing ferrous hydroxide was prepared by mixing 1.0 equivalent of a caustic soda solution with respect to iron ions in an aqueous ferrous sulfate solution. Air was blown in while maintaining the pH of the aqueous solution at around 9, and an oxidation reaction was performed in 90 seconds to prepare a slurry liquid for generating seed crystals. Subsequently, the ferrous sulfate aqueous solution was added to this slurry liquid so that it might become 1.0 equivalent with respect to the original alkali amount (sodium component of caustic soda). Thereafter, the slurry liquid was maintained at pH 8, and the oxidation reaction was advanced while blowing air, and the magnetic particles produced after the oxidation reaction were washed, filtered and once taken out. At this time, a small amount of water-containing sample was collected and the water content was measured. Next, this water-containing sample is re-dispersed in another aqueous medium without being dried, the pH is adjusted to about 6, and the silane coupling agent (n-C ₉ H ₁₇ Si (OCH ₃ ) ₃ ) is stirred sufficiently. 2 parts by mass with respect to 100 parts by mass of magnetic iron oxide were added to perform coupling treatment. The amount of the magnetic material is a value obtained by subtracting the water content from the water-containing sample. The produced magnetic particles are washed, filtered and dried by a conventional method, and then the slightly agglomerated particles are crushed to obtain a surface-treated magnetic material 1 having an average particle size of 0.20 μm and a hydrophobicity of 83. Obtained.

Next, the following materials were uniformly dispersed and mixed using an attritor (Mitsui Miike Chemical Co., Ltd.).
Styrene: 78 parts by mass n-butyl acrylate: 22 parts by mass Divinylbenzene: 0.5 parts by mass Saturated polyester resin (acid value 8, peak molecular weight (Mp) 12000): 2 parts by mass negatively chargeable charge control agent (Hodogaya) Chemical Industry Co., Ltd., trade name: T-77): 1 part by mass surface-treated magnetic substance-1: 88 parts by mass.

  The monomer composition was heated to 60 ° C., and 7 parts of ester wax (maximum endothermic peak 72 ° C. in DSC) was added and dissolved therein. The polymerization initiator 2,2-azobis (2, 4 parts of 4-dimethylvaleronitrile) was dissolved.

On the other hand, it was warmed to 0.1M-Na ₃ PO ₄ aqueous solution 451 parts of the closing and 60 ° C. to 709 parts of ion-exchanged water, was added to 1.0 M-CaCl ₂ aqueous solution 67.7 parts Ca ₃ (PO _{4 2} ) An aqueous medium containing ₂ was obtained. In the aqueous medium, the polymerizable monomer composition was charged, and stirred at 10,000 rpm for 15 minutes in a TK type homomixer (Special Machine Industries Co., Ltd.) at 60 ° C. in an N ₂ atmosphere. Granulated. Thereafter, the mixture was reacted at 70 ° C. for 5 hours while stirring with a paddle stirring blade. Thereafter, the liquid temperature was maintained at 80 ° C., and stirring was further continued for 4 hours. After completion of the reaction, distillation was further carried out at 80 ° C. for 2 hours, after which the suspension was cooled, hydrochloric acid was added to dissolve the dispersant, filtered, washed with water, and dried to give black particles having a weight average particle diameter of 7.5 μm. Got.

100 parts by mass of the black particles and 1.2 parts by mass of hydrophobic silica fine powder were mixed using a Henschel mixer (Mitsui Miike Chemical Co., Ltd.) to prepare a magnetic developer T-1. Here, the hydrophobic silica fine powder is obtained by treating silica having a primary particle diameter of 12 nm with hexamethyldisilazane and then treating with silicone oil, and setting the BET value after treatment to 120 m ² / g.

[Image density]
In the image formation test, a solid image is output at the initial stage and at the end of the durability evaluation, and the density is measured using a Macbeth reflection densitometer (RD918: manufactured by Macbeth) to measure the relative density with respect to an image of a white background portion where the original density is 0.00. The evaluation was made according to the following criteria.
A: Very good 1.40 or more B: Good 1.35 or more, less than 1.40 C: No practical problem 1.00 or more, less than 1.35 D: Practical problem Less than 1.00 [Ghost]
An image corresponding to one round of the sleeve at the tip of the image is placed on a white background with solid black images (squares and circles) arranged at equal intervals, and the other portions are output as halftones. The degree of appearance of a ghost in the image of the image was evaluated according to the following criteria.
A: No difference in shading is observed.
B: A slight shade difference can be confirmed depending on the viewing angle.
C: A ghost is clearly confirmed visually. Practical level lower limit.
D: Ghost appears clearly as light and shade. The density difference can be measured with a reflection densitometer.

[Halftone image unevenness]
A halftone image is output, and blotches (spots, ripples, or carpets) that are likely to occur due to excessive toner charging, and the presence or absence of uneven image density due to uneven charging of the toner are based on the following criteria: evaluated.
A: Neither image nor sleeve can be confirmed at all.
B: A slight density difference can be confirmed on the image.
C: An image defect whose density difference can be visually confirmed is confirmed on the image.
D: An image defect clearly visible on the image is confirmed, and the density difference can be clearly measured with a reflection densitometer.

[Fog]
Ten points of the reflectance of the solid white image in the appropriate image and the reflectance of the unused transfer paper were randomly measured using TC-6DS (manufactured by Tokyo Denshoku). (Worst value of reflectance of solid white image-average value of reflectance of unused transfer paper) was defined as fog density and evaluated according to the following criteria.
A: 1.0% or less (fogging is not visually recognized)
B: 1.0% to 2.0% (Fog is not recognized unless watched)
C: 2.0% to 3.0% (although there is fog, there is no practical problem)
D: 3.0% or more (fogging is conspicuous NG level)
[Example 2]
A developer carrier S-2 was prepared in the same manner as in Example 1 except that the blending ratio of the molybdenum-containing quaternary ammonium salt was changed to 30 parts by mass, its physical properties were measured, and this was used to form an image. And the obtained image was evaluated.

[Example 3]
A developer carrier S-3 was prepared in the same manner as in Example 1 except that the blending ratio of the molybdenum-containing quaternary ammonium salt was changed to 5 parts by mass, its physical properties were measured, and this was used to form an image. And the obtained image was evaluated.

[Example 4]
A developer carrier S-4 was prepared in the same manner as in Example 1 except that the blending ratio of isobutyl alcohol was changed to 350 parts by weight and the blending ratio of methanol to 250 parts by weight, and its physical properties were measured and used. Then, image formation was performed, and the obtained images were evaluated.

[Example 5]
A developer carrier S-5 was prepared in the same manner as in Example 1 except that the coating conditions of the coating liquid were changed to a temperature of 40 ° C. and a relative humidity of 15%, and the physical properties thereof were measured and used. Image formation was performed and the obtained image was evaluated.

[Example 6]
A developer carrier S-6 was produced in the same manner as in Example 1 except that the coating conditions of the coating liquid were changed to a temperature of 28 ° C. and a relative humidity of 80%, and the physical properties thereof were measured and used. Image formation was performed and the obtained image was evaluated.

[Example 7]
A developer carrier S-7 was prepared in the same manner as in Example 1 except that the coating condition of the coating liquid was changed to a temperature of 38 ° C., its physical properties were measured, and image formation was performed using this. The obtained image was evaluated.

[Example 8]
A developer carrier S-8 was prepared in the same manner as in Example 1 except that the molybdenum-containing quaternary ammonium salt was changed to Exemplified Compound 2-2, its physical properties were measured, and this was used to form an image. The obtained images were evaluated.

[Example 9]
A developer carrier S-9 was produced in the same manner as in Example 1 except that the molybdenum-containing quaternary ammonium salt was changed to Exemplified Compound 2-5, its physical properties were measured, and this was used to form an image. The obtained images were evaluated.

[Example 10]
The developer carrier S- is the same as in Example 1 except that the mixing ratio of the sulfur-containing quaternary ammonium salt is changed to 75 parts by mass and the mixing ratio of the molybdenum-containing quaternary ammonium salt is changed to 30 parts by mass. 10 was produced. The physical properties of the obtained developer carrying member S-10 were measured, image formation was performed using the measured physical properties, and the obtained images were evaluated.

[Example 11]
A developer carrier S-11 was prepared in the same manner as in Example 1 except that a coating liquid composed of a mixture of the following materials was used in Example 1, its physical properties were measured, and image formation was performed using this. The obtained images were evaluated.
Resol type phenol resin (J325: manufactured by Dainippon Ink & Chemicals, Inc.) (ammonia catalyst used, containing 40% methanol): 350 parts by mass conductive carbon black (Conductex 975: manufactured by Columbia Carbon Co.): 100 parts by mass containing sulfur Quaternary ammonium salt (Exemplary Compound 1): 60 parts by mass of molybdenum-containing quaternary ammonium salt (Exemplary Compound 2-1): 20 parts by mass of conductive spherical particles (Nikabeads PC1020: manufactured by Nippon Carbon Co., Ltd.): 15 parts by mass of isobutyl alcohol : 270 parts by mass Methanol: 130 parts by mass [Example 12]
A developer carrier S-12 was prepared in the same manner as in Example 1 except that the blending ratio of the graphitized particles A was changed to 30 parts by weight and 70 parts by weight of conductive carbon black was used, and the physical properties thereof were measured. Then, image formation was performed using this, and the obtained image was evaluated.

[Example 13]
As the graphitized particles B, after the production in the same manner as the graphitized particles A, the classification conditions were changed to prepare particles having a volume average particle size of 6.8 μm. A developer carrier S-13 was prepared in the same manner as in Example 1 except that the graphitized particles B were used in place of the graphitized particles A, the physical properties thereof were measured, and image formation was performed using this. Images were evaluated.

[Example 14]
Graphitized particles C were prepared in the same manner as graphitized particles A, and the classification conditions were changed to prepare particles having a volume average particle diameter of 11.2 μm. A developer carrier S-14 was prepared in the same manner as in Example 1 except that the graphitized particles C were used in place of the graphitized particles A, the physical properties thereof were measured, and image formation was performed using this. Images were evaluated.

[Example 15]
Instead of the resole-type phenol resin P1, resole-type phenol resin P2 (TD-2443-LV: manufactured by Dainippon Ink & Chemicals, Inc.) (NaOH catalyst used, containing 40% methanol) was used. Other than that, developer carrying body S-15 was produced like Example 1, the physical property was measured, image formation was performed using this, and the obtained image was evaluated.

[Example 16]
A developer carrier S-16 was prepared in the same manner as in Example 1 except that the blending ratio of isobutyl alcohol was changed to 350 parts by weight and the blending ratio of methanol to 100 parts by weight, and the physical properties thereof were measured and used. Then, image formation was performed, and the obtained images were evaluated.

[Example 17]
A developer carrier S-17 was prepared in the same manner as in Example 1 except that the blending ratio of isobutyl alcohol was changed to 150 parts by weight and the blending ratio of methanol to 300 parts by weight. Then, image formation was performed, and the obtained images were evaluated.

[Example 18]
A developer carrier S-18 was produced in the same manner as in Example 1 except that the blending ratio of isobutyl alcohol was changed to 450 parts by weight and the blending ratio of methanol was changed to 0 part by weight. Then, image formation was performed, and the obtained images were evaluated.

[Example 19]
A developer carrier S-19 was produced in the same manner as in Example 1 except that the blending ratio of isobutyl alcohol was changed to 0 parts by mass and the blending ratio of methanol to 450 parts by weight, and its physical properties were measured and used. Then, image formation was performed, and the obtained images were evaluated.

[Example 20]
A developer carrier S-20 was produced in the same manner as in Example 1 except that isopropyl alcohol was used in place of isobutyl alcohol, the physical properties thereof were measured, and image formation was performed using the developer carrier S-20. Evaluation was performed.

[Example 21]
A developer carrier S-21 was prepared in the same manner as in Example 16 except that isopropyl alcohol was used instead of isobutyl alcohol, the physical properties thereof were measured, and image formation was performed using the developer carrier S-21. Evaluation was performed.

[Example 22]
A developer carrier S-22 was prepared in the same manner as in Example 18 except that carbitol was used in place of isobutyl alcohol, the physical properties thereof were measured, and image formation was performed using the developer carrier S-22. Evaluation was performed.

[Example 23]
A developer carrier S-23 was prepared in the same manner as in Example 18 except that isopropyl alcohol was used instead of isobutyl alcohol, the physical properties thereof were measured, and image formation was performed using the developer carrier S-23. Evaluation was performed.

[Example 24]
Instead of the resole-type phenol resin P1, a resin solution in which 140 parts by mass of 6/66/610 copolymer nylon resin (Elbamide 8023: manufactured by DuPont) was dissolved in 250 parts by mass of methanol was used. Other than that, developer carrying body S-24 was produced like Example 1, the physical property was measured, image formation was performed using this, and the obtained image was evaluated.

[Example 25]
Instead of the resole-type phenol resin P1, a resin solution in which 100 parts by mass of an epoxy resin (2056: manufactured by Three Bond Co., Ltd.) and 50 parts by mass of a curing agent (2191: manufactured by Three Bond Co., Ltd.) was dissolved in 250 parts by mass of toluene was used. Other than that, developer carrying body S-25 was produced like Example 1, the physical property was measured, image formation was performed using this, and the obtained image was evaluated.

  Table 2 shows the physical properties of the developer-carrying members according to Examples 1 to 25. In addition, Tables 3-1 and 3-2 show the results of image evaluation using the developer carrier according to Examples 1 to 25.

[Comparative Example 1]
A developer carrier H-1 was prepared in the same manner as in Example 1 except that the mixing ratio of the sulfur-containing quaternary ammonium salt and the molybdenum-containing quaternary ammonium salt was changed to 0 part by mass, and the physical properties thereof were measured. Then, image formation was performed using this, and the obtained image was evaluated.

[Comparative Example 2]
The blending ratio of isobutyl alcohol was changed to 150 parts by weight, the blending ratio of methanol was changed to 50 parts by weight, and the coating solution was applied at a temperature of 45 ° C. and a relative humidity of 15%. Otherwise, a developer carrier H-2 was prepared in the same manner as in Example 1, the physical properties thereof were measured, image formation was performed using this, and the obtained image was evaluated.

[Comparative Example 3]
The blending ratio of isobutyl alcohol was changed to 400 parts by weight, the blending ratio of methanol to 300 parts by weight, the temperature of the coating solution was changed to 15 ° C., and the coating was performed at 15 ° C. and 40% relative humidity. Otherwise, a developer carrier H-3 was produced in the same manner as in Example 1, the physical properties thereof were measured, image formation was performed using this, and the obtained image was evaluated.

[Comparative Example 4]
A developer carrier H-4 was prepared in the same manner as in Example 1 except that the blending ratio of the molybdenum-containing quaternary ammonium salt was changed to 1.5 parts by mass, and its physical properties were measured. Formation was performed and the resulting images were evaluated.

[Comparative Example 5]
A developer carrier H-3 was prepared in the same manner as in Example 1 except that the mixing ratio of the sulfur-containing quaternary ammonium salt was changed to 5 parts by mass, its physical properties were measured, and this was used for image formation. And the obtained image was evaluated.

  Table 2 shows the physical properties of the developer carrying members according to Comparative Examples 1 to 5. In addition, Table 4-1 and Table 4-2 show the results of image evaluation using the developer carrier according to Comparative Examples 1 to 5.

It is a schematic block diagram which shows an example of the image development apparatus of this invention.

Explanation of symbols

1 Photoconductor (latent image carrier)
2 Developing roller 3 Hopper (container)
4 Magnetic toner (developer)
6 Metal cylindrical tube (base)
7 Conductive resin coating layer 8 Development sleeve (developer carrier)

Claims (3)

A developer carrier having a substrate and a conductive resin coating layer formed on the substrate,
The conductive resin coating layer is formed by a mixture containing a quaternary ammonium salt containing a sulfur atom in the molecule, a quaternary ammonium salt containing a molybdenum atom in the molecule, and a binder resin. Contains sulfur and molybdenum atoms,
The sulfur atom abundance on the surface of the conductive resin coating layer measured by X-ray photoelectron spectroscopy is S0 (atomic%), and the molybdenum atom abundance is M0 (atomic%).
The abundance of sulfur atoms at a depth of 2 μm from the surface of the conductive resin coating layer is S2 (atomic%), the abundance of molybdenum atoms is M2 (atomic%),
When the value of the ratio of S2 to S0 is SX and the value of the ratio of M2 to M0 is MX,
A developer carrier characterized by satisfying the following formulas (a) to (e):
(A) 0.100 ≦ S0 ≦ 1.500
(A) 0.050 ≦ M0 ≦ 1.000
(U) 0.500 ≦ SX
(D) MX ≦ 0.700
(E) 1.200 ≦ SX / MX ≦ 2.000.   It has a container for containing a developer, the developer carrying member, and a developer regulating member that makes the thickness of the developer formed on the surface of the developer carrying member constant. Development device.   The developing device according to claim 2, wherein the container contains a developer.

Images