JP2002244314A - Image forming method, toner and photoreceptor used for the image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming method with high picture quality and a toner, a developer and a photoreceptor for the method by which filming of the toner or the like is not caused on the photoreceptor surface, the photoreceptor surface shows extremely little wear and is hardly scratched even when the toner or the like is removed by cleaning, and the photoreceptor is not damaged. SOLUTION: In the electrophotographic image forming method, the photoreceptor has a charge transfer layer containing a charge transfer material(CTM) and polycarbonate (R) having viscosity average molecular weight of 30,000 to 50,000 in the ratio of 5/10 to 10/10 (CTM/R weight ratio). The following toner is used for the image forming method. The toner is prepared by adding hydrophobic inorganic fine particles (having <=100 nm average particle size of the primary particles) as a post-treatment agent by 0.05 to 2.0 wt.% to a toner having <=15 μm volume average particle size. The toner, developer and photoreceptor are used for the method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming method used in a printer, a copying machine, a light printing machine, and the like, and a toner and a photoreceptor used in the image forming method.

[0002]

2. Description of the Related Art Conventionally, an electrophotographic type is often used as a simple and high-quality image forming method and apparatus.
As a result, competition for technological development is intense, and the performance of electrophotographic technology has been significantly improved. Recently, higher image quality and higher durability have been demanded, and many developments have been made to satisfy the demands, and patent applications have been filed. However, its performance is not enough to meet the current demands. In particular, in order to achieve high image quality and high durability, it is necessary to use a photoreceptor which has good initial performance and has very little deterioration in performance. However, those having good initial performance as a photoreceptor and having high resolution and high sensitivity tend to have low film strength or hardness of a photosensitive material used. In order to maintain high sensitivity performance at high resolution, the material used for the photoreceptor does not deteriorate during long-term use, and toner etc. does not adhere to the photoreceptor surface and filming does not occur, It is important that abrasion or damage is not caused by operations such as cleaning for removing these surface deposits. However, there is no technology that can satisfy such requirements at present.

In recent years, in recent years, photoconductors have been repeatedly used in order to reduce dust from environmental considerations. In particular, in order to achieve high image quality and high durability, the initial performance of the photoconductor used is good, and the performance of the photoconductor repeatedly used for a long period of time including charging, exposure, development, transfer, cleaning, and static elimination is deteriorated. Very few things are needed. In order to obtain a stable image even in repeated use, the photoreceptor is required to have a high level of mechanical strength such as abrasion resistance and prevention of adhesion of toner and paper dust.

[0004] High-resolution and high-sensitivity photosensitive materials tend to have low film strength or hardness. In order to maintain high sensitivity performance at high resolution, the material used for the photoreceptor does not deteriorate during long-term use, and toner etc. does not adhere to the photoreceptor surface and filming does not occur, It is important that abrasion or damage is not caused by operations such as cleaning for removing these surface deposits. In order to solve the above-mentioned drawbacks, the material of the charge transfer layer, which is the outermost surface layer of the photoreceptor, is specified (JP-A-5-158).
No. 248) and the material specification of the cleaning blade (Japanese Patent Application Laid-Open No. 3-20768) have been studied, but they have not satisfied the recent demand for higher durability.

Further, when an inorganic oxide such as silica is added as an additive to the toner, the fluidity is improved and good charging characteristics are obtained. The developer adheres to the carrying / transporting member of the developer and the latent image carrier, and causes a development failure such as a filming phenomenon.
Even if the additive is uniformly attached to the base toner, the state of the additive in the toner changes with time, and the proportion of the additive that is buried in the base toner or detached from the base toner and released is reduced. Increase gradually. As a result, the fluidity deteriorates with the passage of time, so that the charge of the toner tends to be non-uniform, and the chargeability decreases with the lapse of time, causing toner scattering and background contamination to increase. The toner adheres to the carrying member and the latent image carrier to cause a development trouble such as a filming phenomenon, so that sufficient durability cannot be obtained.

[0006]

SUMMARY OF THE INVENTION The present invention does not cause filming of toner or the like on the surface of a photoreceptor. An object of the present invention is to provide a high-quality image forming method that does not hurt the body, a toner for the image forming method, and a photoconductor.

[0007]

In the electrophotographic image forming method and apparatus for achieving high image quality and long life with extremely little wear of the photoreceptor surface, there is a problem that filming due to toner or paper powder is apt to occur. was there. Therefore, the inventors of the present invention have intensively studied a system capable of achieving both reduced wear of the photoconductor and filming.The combination of a highly durable photoconductor having a favorable sensitivity and a high-speed response and a developer having an appropriate abrasion resistance to the photoconductor have been achieved. The inventors have found that they have extremely excellent properties, and have found that the above-mentioned object can be achieved by employing the following means, and have reached the present invention.

A first aspect of the present invention is to provide an electrophotographic image forming method, wherein a charge transfer material (CTM) and a viscosity average molecular weight are 3
50,000 to 50,000 polycarbonate (R)
An electrophotographic photoreceptor having a charge transfer layer of 10/10 (CTM / R weight ratio), and a toner having a volume average particle diameter of 15 μm or less as a post-processing agent in an amount of at least 0.05 to 2.0 wt% based on the toner. Wherein the toner to which the hydrophobic inorganic fine particles (the average particle diameter of the primary particles is 100 nm or less) is added is used.

A second aspect of the present invention is to provide an electrophotographic image forming method, wherein the charge transfer material (CTM) and the viscosity average molecular weight are 3
50,000 to 50,000 polycarbonate (R)
An electrophotographic photoreceptor having a charge transfer layer of 10/10 (CTM / R weight ratio), and an additive release rate of 0.5 to 20
% Of the image forming method.

A third aspect of the present invention is a function-separated type photoconductor in which the photoconductor contains at least a conductive substrate, a charge generation layer, and a charge transfer layer, and the charge transfer layer has an ionization potential of 5.4 to 6. 0 eV in the first image forming method.

A fourth aspect of the present invention is the first to third image forming methods, wherein the contact angle of the surface of the photoreceptor to pure water is 90 ° or more.

In a fifth aspect of the present invention, the charge transfer layer of the photoreceptor has a thickness of 10 to 35 μm.
4 is an image forming method.

A sixth aspect of the present invention is the first to fifth image forming methods, wherein the coverage of the toner with the hydrophobic inorganic fine particles is 30 to 150%.

A seventh aspect of the present invention is that the hydrophobic inorganic fine particles contain 2
The first to sixth image forming methods are characterized by being inorganic fine particles having different primary particle diameters of more than one kind.

An eighth aspect of the present invention is characterized in that the hydrophobic inorganic fine particles are silica, titanium oxide or alumina, or the hydrophobic inorganic fine particles are treated with silicone oil and / or hexamethyldisilazane. In the first to seventh image forming methods.

A ninth aspect of the present invention is that the binder resin of the toner reacts with at least (a) an epoxy resin, (b) a dihydric phenol, and (c) an alkylene oxide adduct of a dihydric phenol or its glycidyl ether. In the above-mentioned first to eighth image forming methods, the synthesized polyol resin has a polyoxyalkylene portion in a main chain.

A tenth aspect of the present invention includes a step of transferring the toner image developed on the photoreceptor to a recording material, and then cleaning the toner remaining on the photoreceptor with a brush and an elastic rubber blade. In the above-mentioned first to ninth image forming methods.

According to an eleventh aspect of the present invention, after the toner image developed on the photosensitive member is transferred to a recording material, the toner remaining on the photosensitive member is brought into contact with the photosensitive member in a counter direction by an elastic rubber. The first to tenth image forming methods are characterized by including a step of performing cleaning with a blade.

A twelfth aspect of the present invention resides in the first to eleventh image forming methods, wherein the developing method is reversal development.

A thirteenth aspect of the present invention is that the volume average particle size is 15 μm.
The following toners are characterized in that at least 0.05 to 2.0 wt% of hydrophobic inorganic fine particles (average particle diameter of primary particles is 100 nm or less) is added as a post-treatment agent to the following toners. 12 is a toner used in any one of the image forming methods.

A fourteenth aspect of the present invention is a charge transfer material (CT).
M) and a polycarbonate (R) having a viscosity average molecular weight of 30,000 or more and 50,000 or less having a charge transfer layer of 5/10 to 10/10 (CTM / R weight ratio). The electrophotographic photosensitive member used in any one of the image forming methods described above.

The polycarbonate used as a binder resin for the charge transfer layer (CTL) in the present invention has high abrasion resistance. Therefore, a high abrasion resistance can be obtained in the charge transfer layer having a larger composition ratio of the polycarbonate to the charge transfer material. However, such a CTL does not provide necessary electrical characteristics, charge injection from the CGL, charge mobility in the CTL, that is, high-speed response, and a significant increase in the residual potential. Further, when a large amount of charge transfer material (CTM) is contained, the charge injection property and the high-speed response can be obtained, but the wear resistance is reduced. Therefore, it is appropriate that the composition ratio (CTM / R ratio) of the charge transfer material (CTM) to the polycarbonate (R) is 5/10 or more and 10/10 (weight ratio) or less.

When the charge transfer layer (CTL) is made thicker, it is possible to reduce the deterioration of the chargeability due to the abrasion. However, the high-speed response is reduced. Further, when a thick film of CTL is coated with a polycarbonate having a large viscosity average molecular weight, a uniform film cannot be obtained. To perform a thick film coating, the viscosity average molecular weight of the polycarbonate is reduced, and It is necessary to increase the solids concentration, but this reduces the wear resistance. Therefore, the CTM / R ratio is 5/10 to 10
/ 10 (weight ratio) and when the molecular weight of R is 30,000 or more and 50,000 or less, the CTL of a thick film with little decrease in chargeability due to abrasion.
Can be applied.

Further, for a toner having a volume average particle diameter of 15 μm or less, 0.05 to 2.0 w
t% of hydrophobic inorganic fine particles (average particle diameter of primary particles is 10%)
By adding (0 nm or less), the hydrophobic inorganic fine particles moderately wear the photoreceptor surface and remove filming-causing substances on the outermost surface of the photoreceptor, thereby preventing filming.
Here, if the addition amount is less than 0.05 wt%, the abrasion property is not sufficiently exhibited, and if the addition amount is more than 2.0 wt%, the image quality is deteriorated due to the influence of the inorganic fine particles, and the filming is caused due to the influence of the inorganic fine particles themselves. Therefore, it is not preferable.
Further, by using a toner having a volume average particle diameter of 15 μm or less, a high-quality image is formed, and by using hydrophobic inorganic fine particles having a primary particle diameter of 100 nm or less, it is possible to prevent adverse effects such as susceptibility to damage to a photoreceptor, and Abrasion and charging characteristics with excellent stability can be realized.

The toner used in the present invention has an additive release rate of 0.5 to 20%, more preferably 1 to 10%.
By doing so, the inorganic fine particles appropriately wear the surface of the photoreceptor, remove the substance causing the fluming on the very surface of the photoreceptor, and prevent filming. Here, if the liberation rate is less than 0.5%, sufficient abrasion is not exhibited due to a low flow-providing effect on the toner, and if it is more than 20%, filming or the like due to the effect of the liberated additive itself occurs. Therefore, it is not preferable.

The release rate of the metal atoms of the present invention can be easily calculated by a particle analyzer. Specifically, after measuring under the following conditions using PT1000 manufactured by Yokogawa Electric Corporation, the liberation rate is determined by applying the synchronization of the emission of the metal atom based on the C atom to the following equation. <<< Measurement conditions of PT1000 manufactured by Yokogawa Electric Corporation >>> * Detection number of C in one measurement: 500 to 1500 * Noise cut level: 1.5 or less * Sort time: 20 digits * Gas: O ₃ 0.1 %, He gas Release rate of metal atoms (count number of metal atoms that did not emit light simultaneously with C atoms) / (count number of metal atoms that emitted light simultaneously with C atoms + count number of metal atoms that did not emit light simultaneously with C atoms) ) × 100

The photoreceptor used in the present invention is a function-separated type photoreceptor containing at least a conductive substrate, a charge generation layer, and a charge transfer layer, and the charge transfer layer has an ionization potential of 5.4 to 6.0 eV. This is more preferable in terms of high sensitivity and low residual potential. In the present invention, the ionization potential of the charge transfer layer refers to a value obtained as a whole of the composition constituting the charge transfer layer, and does not refer to the ionization potential of a specific constituent substance. The ionization potential of the charge transfer layer can be adjusted by a combination of a binder resin, a charge transfer material, and other additives, which are compositions of the charge transfer layer.

The photoreceptor used in the present invention is a photoreceptor having a low friction coefficient in which the surface of the photoreceptor has a contact angle of 90 ° or more with pure water, thereby realizing low abrasion of the photoreceptor. Yes, more preferred. Further, by setting the thickness of the charge transfer layer of the photoreceptor used in the present invention to 10 to 35 μm, a photoreceptor having excellent high-speed response, high image quality, and less charge reduction due to scraping can be obtained, which is more preferable. . Further, by setting the coverage of the toner used in the present invention with the hydrophobic inorganic fine particles to 30% to 150%, a higher quality image can be provided, which is more preferable. If it is smaller than this range, an image or the like in which "missing characters" are conspicuous is likely to occur, which is not preferable. On the other hand, if it is larger than this range, the abrasion on the photoreceptor tends to be too large, which is not preferable. However, in the present invention, since the inorganic fine particles partially adhere to the toner surface in an aggregated state, the actual coverage is low.

It is assumed that the coverage f in the present invention is calculated by the following general formula. f (%) = Σ (√3 / 2π × (D · ρτ) / (d · ρ
s) × C × 100) (where, the particle size of the hydrophobic inorganic fine particles is d, the particle size of the toner is D, ρt and ρs are the true specific gravities of the toner and the hydrophobic inorganic fine particles, respectively. (Weight ratio of hydrophobic inorganic fine particles / toner. If there are several types of hydrophobic inorganic fine particles, the sum of them is the coverage.)

When the hydrophobic inorganic fine particles used in the present invention are at least two kinds of inorganic fine particles having different primary particle diameters, they can function as a toner having excellent fluidity and moderate abrasion, More preferred. The coverage of the toner surface is increased by the inorganic fine particles having a small particle diameter, so that appropriate fluidity can be given to the developer, and faithful reproducibility and a development amount with respect to a latent image at the time of development can be secured. Further, aggregation and solidification of the toner during storage of the developer can be prevented.

When the hydrophobic inorganic fine particles used in the present invention are silica, titanium oxide or alumina,
It can function as a toner having an appropriate abrasion and excellent in charge stability, and is more preferable. By the hydrophobic inorganic fine particles used in the present invention are hydrophobic inorganic fine particles treated with at least silicone oil or hexamethyldisilazane, excellent environmental stability, less image defects such as "letter in characters", High image quality can be achieved, which is more preferable.

The binder resin of the toner used in the present invention is synthesized by reacting at least (a) an epoxy resin, (b) a dihydric phenol, and (c) an alkylene oxide adduct of a dihydric phenol or its glycidyl ether. Further, by using a polyol resin having a polyoxyalkylene moiety in the main chain, it is possible to maintain appropriate abrasion on the photoreceptor, which is more preferable.

According to the electrophotographic image forming method of the present invention, at least a toner image developed on a photoreceptor is transferred to a recording material.
By having a step of cleaning the toner remaining on the photoreceptor with a brush and an elastic rubber blade, in addition to the effect of effectively removing paper dust and filming, it is possible to suppress streak failure due to drum scratches, etc. It is effective and more preferable. Further, after transferring at least the toner image developed on the photoconductor to the recording material, a step of cleaning the toner remaining on the photoconductor with an elastic rubber blade abutted against the photoconductor in the counter direction. Having such an effect is more effective in removing paper dust and filming, and is more preferable.

According to the electrophotographic image forming method of the present invention, after the toner image developed on the photosensitive member is transferred to the recording material, the toner remaining on the photosensitive member is brought into contact with the photosensitive member in the counter direction. More preferably, the method includes a step of performing cleaning with an elastic rubber blade, and the developing method is reversal development. That is, in the reversal development, basically, the polarity of the charge of the toner and the charge of the surface of the photoreceptor are the same, so that the contribution of the van der Waals force is relatively large in the adhesion force of the toner as compared with the influence of the clone force. Since a surface having a low friction coefficient generally has a small surface energy, the van der Waals force can be reduced, which is particularly effective in a reversal developing system.

Hereinafter, the present invention will be described in more detail. However, as long as the structure and the object of the present invention can be achieved, not only those described here but also other materials, manufacturing methods, and processes can be used. The conductive support of the photoreceptor used in the present invention is not particularly limited, but may have a volume resistivity of 10 ¹⁰ Ωcm or less, such as aluminum, titanium, nickel, chromium, nichrome, hastelloy, palladium, and magnesium. , Zinc, copper, gold,
Metals such as platinum, and alloys, tin oxide, indium oxide,
By coating a metal oxide such as antimony oxide by vapor deposition or sputtering or by dispersing it in a resin binder, a plastic on a film or in a cylindrical shape,
Paper or the like, the above-mentioned metal or metal oxide or conductive carbon dispersed and contained in a film or cylindrical plastic or aluminum, aluminum alloy, iron, nickel alloy, stainless alloy,
Plates of titanium alloy and the like, and I. , I .; I. ,
A tube or the like that has been surface-treated by cutting, superfinishing, polishing, or the like after forming into a tube by a method such as extrusion or drawing can be used.

The charge generation layer comprises a charge generation substance alone or a resin layer in which the charge generation substance is dispersed or dissolved. The charge generating substance is not particularly limited. For example, C.I. Pigment Blue 25 [color index (CI) 2118]
0], C.I. Pigment Red 41 (CI 2120
0), CI Acid Red 52 (CI 4510
0), CI Basic Red 3 (CI4521)
0), a phthalocyanine-based pigment having a porphyrin skeleton, an azulenium salt pigment, a squaric salt pigment,
Anthansangthrone-based pigments, azo pigments having a carbazole skeleton (described in JP-A-53-95033),
Azo pigments having a stilbene skeleton (JP-A-53-138)
No. 229), an azo pigment having a triphenylamine skeleton (described in JP-A-53-132547), an azo pigment having a dibenzothiophene skeleton (described in JP-A-54-21728), oxadi Azo pigments having an azole skeleton (described in JP-A-54-12742), azo pigments having a fluorenone skeleton (described in JP-A-54-22834), and azo pigments having a bisstilbene skeleton (described in JP-A-54-22834) -17733), an azo pigment having a distyryloxadiazole skeleton (described in JP-A-54-2129), and an azo pigment having a distyrylcarbazole skeleton (described in JP-A-54-17)
734) and triazo pigments having a carbazole skeleton (JP-A-57-195767, JP-A-57-195767).
And phthalocyanine pigments such as C.I. Pigment Blue 16 (CI74100); C.I.
And organic pigments such as indigo pigments such as C.I.B.D. (CI73030) and perylene pigments such as Argo Scarlet B (manufactured by Violet) and Indus Scarlet R (manufactured by Bayer). Preferably a metal or metal-free phthalocyanine compound (more preferably titanyl phthalocyanine, hydroxypotassium phthalocyanine, most preferably titanyl phthalocyanine having a maximum peak at a Bragg angle 2θ of 27.2 ° with respect to Cu-Kα radiation) or an anthranthrone compound And the like are preferably used. These may be used as a mixture of two or more as necessary.

The thickness of the charge generation layer is suitably about 0.05 to 2 μm, and preferably 0.1 to 1 μm. The charge generation layer is formed by dispersing or dissolving a charge generation material together with a resin binder in a solvent, and coating and drying the charge generation material on a substrate or an undercoat layer. As the resin binder, polystin, styrene-butadiene copolymer, styrene-acrylonitrile copolymer, styrene-maleic anhydride copolymer, polyester, polyarylate, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polystyrene Vinyl acetate, polyvinylidene chloride, polyacrylate, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl acetal, polyvinyl formal, phenoxy resin, polyvinyl pyridine, poly-N-vinyl carbazole, acrylic resin, silicone resin, nitrile rubber, Thermoplastic or thermosetting resin such as chloroprene rubber, butadiene rubber, epoxy resin, melamine resin, urethane resin, phenol resin, alkyd resin, etc. Poly -N- vinylcarbazole and the like if, but not limited thereto. These binder resins are used alone or in combination. The ratio of the charge generating substance to the binder material used is 100: 0 to 10 by weight.
0:50 is preferred.

As the solvent, benzene, toluene, xylene, methylene chloride, dichlorobenzene, monochlorobenzene, dichlorobenzene, ethyl alcohol, methyl alcohol, butyl alcohol, isopropyl alcohol, ethyl acetate, butyl acetate, methyl ethyl ketone, dioxane, tetrahydrofuran , Cyclohexane, methyl cellosolve, ethyl cellosolve and the like,
It is not limited to these. These solvents can be used alone or as a mixture.

In the present invention, an undercoat layer is preferably provided between the photosensitive layer and the substrate in order to improve the charge blocking property. Such an undercoat layer generally contains a resin as a main component. Examples of such a resin include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymerized nylon and methoxymethylated nylon, polyurethane, melamine resins, phenol resins, and epoxy resins. Examples include, but are not limited to, a curable resin that forms a network structure, a silane coupling agent, and a ceramic based organic chelate compound.

A photosensitive layer is provided on the undercoat layer. The photosensitive layer may have a single layer structure or a laminated structure, but preferably has a so-called function-separated type laminated structure having a charge generation layer and a charge transfer layer. The charge transfer layer is composed of a charge transfer material (CTM) and a polycarbonate (R) having a viscosity average molecular weight of 30,000 or more and 50,000 or less.
TM / R ratio is not particularly limited except that the weight ratio is 5/10 or more and 10/10 or less.

Polycarbonates containing various skeletons are known, and all known polycarbonates can be used. For example, a polycarbonate resin containing at least one selected from a polymer or a copolymer having structural units represented by the following general formulas (1) to (4) as main repeating units may be mentioned.

[0042]

Embedded image [R _{1 to} R _{8 in} the general formula (1) each represent a hydrogen atom, a halogen atom, a lower alkyl group or an aryl group, and R ₉ , R ₁₀
Represents a hydrogen atom, a lower alkyl group, or an aryl group. However, at least one of R _{1 to} R ₈ is a halogen atom, a lower alkyl group or an aryl group, or at least one of R ₉ and R ₁₀ is a lower alkyl group or an aryl group having 3 or more carbon atoms. . Further, R _{1 to} R ₈ in the general formulas (2) to (4) each represent a hydrogen atom,
A halogen atom or a lower alkyl group, R _{9 to} R _{12 each} represent a hydrogen atom, and a lower alkyl group or an aryl group Z represents an atom group necessary for forming a carbon ring or a heterocyclic ring. A ₁ represents —C (R ₁₃ ) (R ₁₄ ) —, —Si (R ₁₅ ) (R ₁₆ ) —,
_{-S -, - SO 2 -,} - CO -, - O- or - (CH ₂₎
n- (where n is an integer of 2 or more, R ₁₃ and R ₁₄ are bonded to each other to form a carbocyclic or heterocyclic ring, and R ₁₅ and R ₁₆ are each a substituted or unsubstituted alkyl or aryl group, l And m represent l (l + m) = 0.1 to 0.9), and the like, but are not limited thereto.

Examples of the CTM include carbazole derivatives, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives, imidazolidine derivatives, bisimidazolidine derivatives, styryl compounds, hydrazone compounds, and pyrazoline. Derivatives, oxazolone derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran derivatives, acridine derivatives,
Phenazine derivatives, aminostilbene derivatives, triarylamine derivatives, phenylenediamine derivatives, stilbene derivatives, benzidine derivatives, poly-N-vinylcarbazole, poly-1-vinylpyrene, poly-9-vinylanthracene, but are not limited thereto. Not necessarily. These may be used alone or in combination of two or more. The thickness of the charge transfer layer is preferably from 10 to 35 μm.

As the charge transport material, a hydrazone compound,
Pyrazoline compounds, styryl compounds, triphenylmethane compounds, oxadiazole compounds, carbazole compounds, stilbene compounds, enamine compounds, oxazole compounds, triphenylamine compounds, tetraphenylbenzidine compounds, various compounds such as azine compounds, It is preferable to select a substance having a high ionization potential of the transport substance itself. However, butadiene compounds or pyrazoline compounds tend to have a relatively low ionization potential, but the ionization potential is also affected by the substituents. You have to choose. As a substituent, an electron-accepting group such as a nitro group or a halogen atom tends to increase the ionization potential.

In the present invention, the value measured by a surface analyzer (AC-1; manufactured by Riken Keiki Co., Ltd.) was used as the ionization potential. The contact angle of the photoreceptor surface to pure water is measured using a contact angle meter CA-DT.A (Kyowa Interface Science Co., Ltd.)
The value measured by the droplet method (the detailed description of the measurement procedure is provided in the instruction manual) was used.

The photoreceptor of the present invention may be used in any of the layers of the photoreceptor in order to reduce fatigue deterioration upon repeated use or to improve durability. An antioxidant, a UV absorber, an electron-accepting substance, a surface modifier, a plasticizer and the like, and an environment-dependent reducing agent such as a plasticizer can be added in an appropriate amount as needed and used. In particular, as an additive to be added to the charge transport layer, the addition of an antioxidant is effective in adjusting the ionization potential, and the addition of the antioxidant makes it possible to increase the ionization potential. If necessary, a protective layer or the like may be provided in addition to the ordinary photosensitive layer.

A coating method is most commonly used as a layer forming method, and a coating liquid is applied by a dip coating method, a spray coating method, a blade coating method, a spinner coating method, a bead coating method, a curtain coating method, or the like. A circular amount control type coating method or the like can be used.

Examples of the inorganic fine particles added to the toner of the present invention include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, iron oxide, copper oxide, zinc oxide, and tin oxide. , Silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, red iron oxide, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride, etc. be able to. Among them, silica, titanium oxide and alumina are particularly preferred, but are not particularly limited. The amount of addition is from 0.05 to 2.
0 wt%, preferably 0.3 to 1.5 wt% can be used. As those preferably used in the present invention, MOX80 (average particle diameter, about 40 nm), OX50 (average particle diameter, about 40 nm) and TT600 (average particle diameter, about 40 nm) manufactured by Nippon Aerosil Co., Ltd., manufactured by Idemitsu Kosan Co., Ltd. IT-PB (average particle size, about 40 nm) and IT-PB
PC (average particle diameter, about 60 nm), manufactured by Fuji Titanium Industry Co., Ltd., TAF110A (average particle diameter, about 40 to 50 nm)
And TAF510 (average particle size, about 40 to 50 nm) and the like can be conveniently used. These inorganic fine particles may be used alone or in combination of two or more.

Examples of the hydrophobizing agent include dimethyl silicone oil, methylphenyl silicone oil, chlorophenyl silicone oil, methyl hydrogen silicone oil, alkyl-modified silicone oil, fluorine-modified silicone oil, polyether-modified silicone oil, and alcohol-modified silicone oil. , Amino-modified silicone oil, epoxy-modified silicone oil, epoxy / polyether-modified silicone oil, phenol-modified silicone oil, carboxyl-modified silicone oil, mercapto-modified silicone oil, acrylic,
Silicone oils such as methacryl-modified silicone oil and α-methylstyrene-modified silicone oil, silane coupling agents, silylating agents, silane coupling agents having an alkyl fluoride group, organic titanate coupling agents, and aluminum coupling agents And the like are preferred surface treatment agents, but are not particularly limited. By treating these inorganic fine particles with these hydrophobizing agents, the hydrophobic inorganic fine particles used in the present invention are prepared.

The average particle size of the primary particles of the hydrophobic inorganic fine particles used in the present invention is 100 nm or less, preferably 70 nm.
It is as follows. If it is larger than this range, the surface area of the inorganic fine particles becomes small, and the effect is hardly exhibited. The average particle diameter here is a number average particle diameter. The particle diameter of the inorganic fine particles used in the present invention can be determined by a particle size distribution measuring device using dynamic light scattering, for example, DLS-70 manufactured by Otsuka Electronics Co., Ltd.
0 and Coulter Electronics Coulter N4
However, since it is difficult to dissociate the secondary agglomeration of the particles after the silicone oil treatment, it is preferable to directly determine the particle size from a photograph obtained by a scanning electron microscope or a transmission electron microscope. In this case, at least 100 or more inorganic fine particles are observed, and the average value of the major axis is determined.

The toner for electrophotography used in the present invention is a toner for electrophotography having at least a binder resin and a colorant, for example, having a volume average particle diameter of 15 μm or less. As the developer used in the present invention, any known methods and materials can be used.

As the binder resin for the toner used in the present invention, styrene such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene and its substituted polymers; styrene-p-chlorostyrene copolymer, styrene-propylene copolymer Polymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer,
Styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene- Acrylonitrile copolymer, styrene-
Styrenes such as vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer Copolymer; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic resin, rosin, modified rosin, Examples thereof include terpene resins, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes, and the like, which can be used alone or in combination.

In consideration of the abrasion property with the photoreceptor, (a) an epoxy resin, (b) a dihydric phenol, and (c) an alkylene oxide adduct of a dihydric phenol or a glycidyl ether thereof are synthesized. It is preferable to use a polyol resin having a polyoxyalkylene moiety in the main chain as the binder resin. Here, the epoxy resin is preferably obtained by reacting a bisphenol such as bisphenol A or bisphenol F with epichlorohydrin, and the dihydric phenol includes bisphenol A and bisphenol F. Examples of the alkylene oxide adduct of dihydric phenol or glycidyl ether thereof include ethylene oxide, propylene oxide, butylene oxide, and a reaction product of a mixture thereof with a bisphenol such as bisphenol A or bisphenol F. The resulting product may be converted to glycidyl ether with epichlorohydrin or β-methyl epichlorohydrin. Further, a monohydric phenol such as phenol, cresol, isopropylphenol, aminophenol, octylphenol, nonylphenol, dodecylphenol, p-cumylphenol may be reacted.

As the colorant for the toner used in the present invention, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium Muum yellow, yellow iron oxide, ocher, graphite, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (G
R, A, RN, R), Pigment Yellow L, Benzidine Yellow (G, GR), Permanent Yellow (NC
G), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Lead Tan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimony Vermilion, permanent red 4
R, Para Red, Phisay Red, Para Chlor Ortho Nitroaniline Red, Risor Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine Min BS, Permanent Red (F2R, F4
R, FRL, FRLL, F4RH), Fast Scarlet VD, Belcan Fast Rubin B, Brilliant Scarlet G, Lisor Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Museum, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B,
Thioindigo maroon, oil red, quinacridone red, pyrazolone red, polyazo red, chrome vermillion, benzidine orange, perinone orange,
Oil orange, cobalt blue, cerulean blue,
Alkaline blue lake, peacock blue lake, Victoria blue lake, metal-free phthalocyanine blue, phthalocyanine blue, fast sky blue, indanthrene blue (RS, BC), indigo, ultramarine, navy blue,
Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chromium Oxide, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lakes, malachite green lakes, phthalocyanine greens, anthraquinone greens, titanium oxide, zinc white, lithobon and mixtures thereof can be used. The amount used is generally 0.1 to 5 parts by weight per 100 parts by weight of the binder resin.
0 parts by weight.

The developer of the present invention may contain a charge controlling agent, if necessary. As the charge control agent, any known charge control agents can be used. For example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified) Quaternary ammonium salts), alkylamides, phosphorus simple substances or compounds,
Tungsten alone or compound, fluorine-based activator, metal salt of salicylic acid, metal salt of salicylic acid derivative and the like. Specifically, bontron 03 of a nigrosine dye, bontron P-51 of a quaternary ammonium salt, bontron S-34 of a metal-containing azo dye, E-82 of an oxynaphthoic acid-based metal complex, and E-82 of a salicylic acid-based metal complex 84, phenolic condensate E-89 (all manufactured by Orient Chemical Industries, Ltd.), quaternary ammonium salt molybdenum complex TP-
302, TP-415 (manufactured by Hodogaya Chemical Industry Co., Ltd.),
Copy charge PSY VP2 of quaternary ammonium salt
038, copy blue P of triphenylmethane derivative
R, copy charge of quaternary ammonium salt NEGV
P2036, Copy Charge NX VP434 (above, manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (manufactured by Nippon Carlit), copper phthalocyanine, perylene, quinacridone, azo pigments, other sulfonic acid groups, carboxyl groups And high molecular compounds having a functional group such as quaternary ammonium salts.

In the present invention, the amount of the charge control agent used is determined by the type of the binder resin, the presence or absence of additives used as required, and the toner production method including the dispersion method, and is uniquely limited. However, preferably, 0.1 to 100 parts by weight of the binder resin
Used in the range of 10 parts by weight. Preferably, the range is 2 to 5 parts by weight. If the amount exceeds 10 parts by weight, the chargeability of the toner is too large, and the effect of the main charge control agent is reduced,
The electrostatic attraction with the developing roller increases, which causes a decrease in the fluidity of the developer and a decrease in image density.

In order to impart a releasability to the developer used in the present invention, it is preferable that a wax is contained in the produced developer. The melting point of the wax is 40-12.
The temperature is 0 ° C., particularly preferably 50 to 110 ° C. When the melting point of the wax is too high, the fixability at low temperatures may be insufficient, while when the melting point is too low, the offset resistance and durability may decrease. The melting point of the wax is determined by a differential scanning calorimetry ( DSC)
Can be determined by: That is, the melting peak value when a few mg of the sample is ripened at a constant heating rate, for example (10 ° C./min), is defined as the melting point.

Examples of the wax that can be used in the present invention include solid paraffin wax, micro wax, rice wax, fatty acid amide wax, fatty acid wax, aliphatic monoketones, fatty acid metal salt wax, and fatty acid ester wax. And partially saponified fatty acid ester waxes, silicone varnishes, higher alcohols, and carnauba wax. Polyolefins such as low molecular weight polyethylene and polypropylene can also be used. In particular, a polyolefin having a softening point of 70 to 150 ° C by a ring and ball method is preferable,
Further, a polyolefin having a softening point of 120 to 150 ° C is preferable.

Examples of the cleaning property improver for removing the developer after transfer remaining on the photoreceptor and the primary transfer medium include fatty acid metal salts such as zinc stearate, calcium stearate, and stearic acid, for example, fine particles of polymethyl methacrylate, Examples include polymer fine particles produced by soap-free emulsion polymerization of polystyrene fine particles and the like. The polymer fine particles preferably have a relatively narrow particle size distribution and a volume average particle size of 0.01 to 1 μm.

The toner particles used in the present invention can be mainly produced by a pulverization method or a polymerization method. As the production method, for example, at least a binder resin,
A toner manufacturing method including a step of mechanically mixing a developer component containing a main charge control agent and a pigment, a step of melt-kneading, a step of pulverizing, and a step of classifying can be employed.
Further, in the mechanical mixing step and the melt kneading step, a production method in which powder other than particles serving as a product obtained in a pulverizing or classifying step is returned and reused is also included. The powder (by-product) other than the particles that become the product referred to here is mixed with the fine particles and coarse particles other than the component that becomes the product having the desired particle size obtained in the pulverization step after the step of melt-kneading, and in the subsequent classification step. It means fine particles and coarse particles other than the components that generate the desired particle size. In the mixing step or the melt-kneading step of such a by-product, it is preferable to mix the raw materials and preferably the by-product 1 at a weight ratio of the other raw materials 50 to the by-product 50 from the other raw materials 99.

The mixing step of mechanically mixing at least the developer components including the binder resin, the main charge controlling agent, the pigment, and the by-products is carried out under ordinary conditions using an ordinary mixer with rotating blades. There is no particular limitation. After the completion of the mixing step, the mixture is charged into a kneader and melt-kneaded. As the melt kneader, a uniaxial or biaxial continuous kneader or a batch kneader using a roll mill can be used. For example, a KTK twin screw extruder manufactured by Kobe Steel, a TEM extruder manufactured by Toshiba Machine Co., a twin screw extruder manufactured by KCK, a PCM twin screw extruder manufactured by Ikegai Iron Works, Bus A co-kneader or the like is preferably used. It is important that the melt-kneading is performed under appropriate conditions so as not to cause the molecular chains of the binder resin to be cut. Specifically, the melt-kneading temperature should be determined with reference to the softening point of the binder resin. If the temperature is lower than the softening point, cutting is severe, and if the temperature is too high, dispersion does not proceed. After the above melt kneading process is completed,
Next, the kneaded material is pulverized. In this pulverization step, it is preferable to first perform coarse pulverization and then finely pulverize. At this time, it crushes by colliding with the collision plate in the jet stream,
A method in which pulverization is performed with a narrow gap between a rotor that rotates mechanically and a stator is preferably used. After the completion of the pulverizing process, the pulverized material is classified in a gas stream by centrifugal force or the like,
Thus, a developer having a predetermined particle size, for example, an average particle size of 5 to 20 μm is manufactured.

In preparing the developer, in order to enhance the fluidity, storage property, developability and transferability of the developer, the hydrophobic silica mentioned above is further added to the developer produced as described above. Inorganic fine particles such as fine powder may be added and mixed. A general powder mixer is used for mixing the external additives, but it is preferable that the internal temperature can be adjusted by providing a jacket or the like.
In order to change the history of the load applied to the external additive, the external additive may be added during or gradually. Of course, the rotation speed, rolling speed, time, temperature, etc. of the mixer may be changed. A strong load may be applied first, followed by a relatively weak load, or vice versa. Examples of mixing equipment that can be used include a V-type mixer, a rocking mixer, a Lodige mixer, a Nauter mixer, a Henschel mixer, and the like.

When the toner used in the present invention is used for a two-component developer, the toner may be mixed with a magnetic carrier, and the content ratio of the carrier to the toner in the developer is 100 parts by weight of the carrier. 1 to 10 parts by weight is preferred. As the magnetic carrier, conventionally known ones such as iron powder, ferrite powder, magnetite powder, and magnetic resin carrier having a particle diameter of about 20 to 200 μm can be used. Further, as the coating material, amino resins, for example, urea-formaldehyde resin, melamine resin, benzoguanamine resin,
Urea resin, polyamide resin, epoxy resin and the like can be mentioned. Further, polyvinyl and polyvinylidene resins, for example, acrylic resins, polymethyl methacrylate resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins, polystyrene resins such as polystyrene resins and styrene acrylic copolymer resins, polychlorinated resins Halogenated olefin resin such as vinyl, polyester resin such as polyethylene terephthalate resin and polybutylene terephthalate resin, polycarbonate resin, polyethylene resin, polyvinyl fluoride resin, polyvinylidene fluoride resin, polytrifluoroethylene resin, polyhexafluoro Propylene resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene and vinylidene fluoride Monomers including a fluoro terpolymers such, and silicone resins. If necessary, a conductive powder or the like may be contained in the coating resin. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide and the like can be used. These conductive powders preferably have an average particle size of 1 μm or less. When the average particle diameter is larger than 1 μm, it becomes difficult to control the electric resistance. Further, the toner of the present invention can be used as a one-component magnetic toner or a non-magnetic toner without using a carrier.

In the image forming system of the present invention, the load of the cleaning blade can be made lower than that of the conventional one, and the adhesion of paper dust does not occur, but this is extremely advantageous for reducing the wear of the photosensitive layer. Although any material can be used for the constituent material of the cleaning brush according to the present invention, it is preferable to use a fiber-forming polymer having hydrophobicity and high dielectric constant. Examples of such high-molecular polymers include rayon, nylon, polycarbonate, polyester, methacrylic resin, acrylic resin, polyvinyl chloride, polyvinylidene chloride, polypropylene, polystyrene, polyvinyl acetate, styrene-butadiene copolymer, and vinylidene chloride. -Acrylonitrile copolymer, vinyl chloride-
Vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone-alkyd resin, phenol formaldehyde resin, styrene-alkyd resin, polyvinyl acetal (for example, polyvinyl butyral), and the like. It is not limited to. These resins can be used alone or as a mixture of two or more. Particularly preferred are rayon, nylon, polyester, acrylic and polypropylene. The cleaning brush used in the present invention may be either conductive or insulative. A cleaning brush containing a low-resistance substance such as carbon in a constituent material and adjusted to an arbitrary resistance can be used. As a support used for the brush, metal such as stainless steel and aluminum, paper, plastic, and the like are mainly used, but the present invention is not limited thereto. The thickness of the single fiber of the brush is preferably 6 to 30 denier, and the fiber density is 4.5 × 10 ^{2 to} 15.5 × 10 ² f / cm ^2, but is not particularly limited. Here, “denier” is a numerical value obtained by measuring a weight of 9000 m of a fiber constituting the brush in units of g (gram). The brush is preferably configured such that a fur brush is provided on the surface of a cylindrical support with an adhesive layer interposed therebetween. If necessary, a member (flicker) for knocking off the toner and foreign matters adhering to the brush roller from the brush may be provided.

The elastic rubber blade used in the present invention is preferably configured to have a free end on a supporting member, but is not limited to this. It is preferable that the free end of the elastic rubber blade is pressed against the opposite side (counter) of the photosensitive drum in the rotation direction. The rubber hardness of the elastic rubber blade is JIS A 60 to 70 °, the rebound resilience is 30 to 70%, and the Young's modulus is 30 to 60 kgf /
cm ² , thickness is 1.5 to 3.0 mm, free length is 7 to 12
mm, and the pressing force on the photoreceptor is preferably 15 g / cm or less.

As the image forming process used in the present invention, all known processes satisfying the conditions such as the conventional electrophotographic process can be used. In addition, a color image forming process using two or more color toners may be used instead of the toner single color process. At the time of image reading, the signal for each separated color that has been color-separated is charged, the process of image writing by laser light exposure and the process of developing the corresponding color toner are repeated, yellow,
Four-color toner images of magenta, cyan, and black toners may be formed on the photoconductor and transferred collectively to recording paper. Further, the method of forming the toner image and the method of transferring the toner image to the recording material may be different.

In addition to the above-described image forming process, image information is stored in advance in an image memory such as a ROM or a floppy (registered trademark) disk, and if necessary, the information in the image memory is extracted and output to the image forming unit. be able to. Therefore, not only an apparatus having an image reading unit but also an apparatus for storing information from a computer or the like in a memory and outputting the information to the image forming unit is included in the image forming apparatus of the present invention. The most common of these are LED printers and LBP
(Laser beam printer).

[0068]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited to only these Examples. In the following examples, parts and percentages are by weight unless otherwise specified. The evaluation results are shown in Table 1.

Example 1 <Preparation of photoreceptor> Alcohol-soluble nylon (polyamide resin: trade name,
CM8000 manufactured by Toray Co., Ltd.) as an undercoating layer of about 0.2 μm, followed by dip coating with the following charge generation layer coating solution, followed by heating and drying at 110 ° C. for 10 minutes to obtain a charge of about 0.2 μm. A generating layer was formed. [Coating liquid for charge generation layer] A sintered zirconium oxide ball (YTZ ball) having a volume of 1/2 and a volume of 1/2 cm in a glass pot of φ15 cm and polyvinyl butyral (trade name X
(YHL), 300 parts of a cyclohexanone solution and 12 parts of Y-type titanyl phthalocyanine were charged and milled for 72 hours. Further, 500 parts of methyl ethyl ketone was additionally charged and milling was further performed for 24 hours to obtain a charge generation layer coating. Next, the following charge transfer layer coating solution was applied onto the charge generation layer by dip coating, and dried by heating at 130 ° C. for 30 minutes to form a 30 μm charge transfer layer. [Charge transfer layer coating solution] Compound represented by the following formula 2 Polycarbonate (viscosity average molecular weight 40,000) 100 parts Silicone oil 0.3 parts Methylene chloride 800 parts

[0070]

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<Preparation of Developer> [Matrix Colored Particles for Toner] 1200 parts of water 200 parts of a phthalocyanine green water-containing cake (solid content 30%) 200 parts 540 parts of carbon black (MA60 manufactured by Mitsubishi Chemical Corporation) were thoroughly stirred with a flasher. Here, a polyester resin (acid value; 3, hydroxyl value; 25, Mn; 45000,
(Mw / Mn; 4.0, Tg; 60 ° C.) 1200 parts were added, kneaded at 150 ° C. for 30 minutes, 1000 parts of xylene was added, kneading was further performed for 1 hour, water and xylene were removed, roll-cooled, and pulverized with a pulperizer. A masterbatch pigment was obtained.

Polyester resin (acid value 3: hydroxyl value)
25: Mn 45000: Mw / Mn 4.0: Tg
(60 ° C.) 100 parts, 5 parts of the above master batch, and a charge control agent (Bontron E-84 manufactured by Orient Chemical Co., Ltd.)
After mixing 4 parts with a mixer, the mixture was melt-kneaded with a two-roll mill, and the kneaded product was rolled and cooled. After that, an impingement plate type pulverizer (type I mill; manufactured by Nippon Pneumatic Industries, Ltd.) using a jet mill and a wind classifier (DS classifier; manufactured by Nippon Pneumatics Co., Ltd.) using a swirling flow were performed to obtain a volume average diameter of 13.5 μm.
m colored particles were obtained.

600 parts of water 1200 parts of Pigment Yellow 17 water-containing cake (50% of solid content) was thoroughly stirred with a flasher. Here, a polyester resin (acid value; 3, hydroxyl value; 25, Mn; 45000,
(Mw / Mn; 4.0, Tg; 60 ° C.) 1200 parts were added, kneaded at 150 ° C. for 30 minutes, 1000 parts of xylene was added, kneading was further performed for 1 hour, water and xylene were removed, roll-cooled, and pulverized with a pulperizer. Further, two passes were performed with three rolls to obtain a master batch pigment.

Polyester resin (acid value; 3, hydroxyl value;
25, Mn; 45000, Mw / Mn; 4.0, Tg;
(60 ° C.), 100 parts, 5 parts of the above-mentioned master wasp and 4 parts of a charge controlling agent (Bontron E-84 manufactured by Orient Chemical Co., Ltd.) were mixed by a mixer, then melt-kneaded by a two-roll mill, and the kneaded material was rolled and cooled. Thereafter, pulverization and classification were performed in the same manner as in the production example of the black colored particles to obtain yellow colored particles having a volume average diameter of 13.2 μm. 600 parts of water and Pigm
ent Red 57 water-containing cake (50% solid content) 12
00 parts were stirred well with a flasher. Here, a polyester resin (acid value; 3, hydroxyl value; 25, Mn; 450)
(200, Mw / Mn; 4.0, Tg; 60 ° C), kneaded at 150 ° C for 30 minutes, kneaded at 150 ° C for 30 minutes, kneaded with 1000 parts of xylene, kneaded for 1 hour, removed water and xylene, rolled and cooled, and pulped with a pulperizer. The mixture was pulverized and further passed through a three-roll mill for two passes to obtain a master batch pigment.

Polyester resin (acid value; 3, hydroxyl value;
25, Mn; 45000, Mw / Mn; 4.0, Tg;
(60 ° C.) 100 parts of a polyester resin, 5 parts of the above master batch, and 4 parts of a charge controlling agent (Bontron E-84 manufactured by Orient Chemical Co., Ltd.) were mixed by a mixer, then melt-kneaded by a two-roll mill, and the kneaded material was rolled and cooled. . Thereafter, pulverization and classification were performed in the same manner as in the production example of black colored particles to obtain magenta colored particles having a volume average diameter of 13.5 μm.

[0076] 600 parts of water and Pigment Blue
e 15: 3 1200 parts of a water-containing cake (solid content 50%) was thoroughly stirred with a flasher. Here, a polyester resin (acid value; 3, hydroxyl value; 25, Mn; 45000,
(Mw / Mn; 4.0, Tg; 60 ° C.) 1200 parts were added, kneaded at 150 ° C. for 30 minutes, 1000 parts of xylene was added, kneading was further performed for 1 hour, water and xylene were removed, roll-cooled, and pulverized with a pulperizer. The mixture was further passed through a three-roll mill for two passes to obtain a master batch pigment.

Polyester resin (acid value; 3, hydroxyl value;
25, Mn; 45000, Mw / Mn; 4.0, Tg;
(60 ° C.) 100 parts, the above-mentioned master batch 3 parts, and a charge controlling agent (Bontron E-84 manufactured by Orient Chemical Co., Ltd.)
After mixing 4 parts with a mixer, the mixture was melt-kneaded with a two-roll mill, and the kneaded product was rolled and cooled. Thereafter, pulverization and classification were performed in the same manner as in the production example of black colored particles, and the volume average diameter was 13.
4 μm of cyan colored particles were obtained.

[Mixing with External Additives] 100 parts by weight of the obtained four colored particles and 1.0 part by weight of hydrophobic silica H2000 (average particle diameter of primary particles: 10 nm, Clariant Japan) were mixed using a Henschel mixer. , Aperture 50μ
By removing the aggregate by passing through a sieve of m, an electrophotographic toner was obtained.

[Mixing of Carrier and Toner] A ferrite carrier having an average particle diameter of 50 μm coated with a silicone resin at an average thickness of 0.3 μm is used, and a container is rolled with 5 parts by weight of each color toner per 100 parts by weight of the carrier. The mixture was uniformly mixed and charged by using a turbuler mixer of a type which was stirred to prepare a developer.

<Image Forming Apparatus> The photoreceptor and the developer prepared as described above are developed by a four-color developing unit using a two-component developer on a single drum-shaped photoreceptor to form an intermediate transfer member. Imagio Color 2800, a full-color laser copying machine that sequentially transfers and transfers all four colors to transfer paper at once
(Ricoh) was evaluated using a modified apparatus. The evaluation machine is a reversal development system in which the polarity of the electrostatic latent image on the photoconductor and the polarity of the non-magnetic one-component developer are the same.

Example 2 Example 1 was repeated except that the ionization potential was adjusted to 5.7 eV by changing the type and amount of the antioxidant added to the charge transfer layer of the photoreceptor. Was evaluated.

Example 3 In Example 1, the polycarbonate resin of the charge transfer layer of the photoreceptor was changed to a siloxane copolymerized polycarbonate having a contact angle of 98 ° with pure water (compound of the following formula 3 having a viscosity average molecular weight of 40,000). Except for this, evaluation was performed in the same manner as in Example 1.

[0083]

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Example 4 Evaluation was made in the same manner as in Example 1 except that the thickness of the charge transfer layer (CTL) of the photosensitive member was changed to 11 μm.

Embodiment 5 The volume average particle diameter of the toner and the primary particle diameter of the hydrophobic inorganic fine particles are set within the range defined in claim 1 so that the coverage of the toner with the hydrophobic inorganic fine particles in Example 1 is 33%. The amount of addition was adjusted.

Example 6 The volume average particle diameter of the toner and the primary particle diameter of the hydrophobic inorganic fine particles are set within the range defined in claim 1 so that the coverage of the toner with the hydrophobic inorganic fine particles in Example 1 is 140%. The amount of addition was adjusted.

Example 7 In Example 1, with respect to 100 parts by weight of the colored particles, 0.5 part by weight of hydrophobic silica H2000 (average particle diameter of primary particles: 10 nm, Clariant Japan) and titanium dioxide MT
Evaluation was carried out in the same manner as in Example 1 except that 0.6 part by weight of -150 AFM (average particle diameter of primary particles: 15 nm, Taker) was mixed.

Example 8 In Example 1, 0.2 parts by weight of hydrophobic silica H2000 (average particle diameter of primary particles: 10 nm, Clariant Japan) and 100 parts by weight of colored particles were mixed with hydrophobic silicone oil-treated silica RY50 (primary particles). Average particle size 40
nm, Nippon Aerosil) 1 part by weight, (titanium dioxide MT
The evaluation was performed in the same manner as in Example 1 except that 0.3 parts by weight of -150 AFM (average particle diameter of primary particles: 15 nm, Taker) was mixed.

Example 9 Colloidal silica fine powder AEROSIL as an external additive
TT600 (manufactured by Nippon Aerosil Co., Ltd., average primary particle size:
(0.04 μm) and 100 g of dimethyl silicone oil [KF-96, 100cs (manufactured by Shin-Etsu Chemical Co., Ltd.)] diluted with a solvent were mixed with a Henschel mixer (manufactured by Mitsui Miike), dried, and dried at 260 ° C. Heat treatment was performed to obtain silica a surface-treated with 35% by weight of dimethyl silicone oil. Methyltrimethoxysilane 40
g of methanol-water (95: 5) in which 100 g of washed titania CR-EL (manufactured by Ishihara Sangyo Co., Ltd., average primary particle diameter: 0.3 μm) was added, followed by ultrasonic dispersion. Next, after evaporating methanol and the like in the dispersion with an evaporator and drying, the dispersion is heat-treated in a dryer set at 120 ° C., pulverized in a mortar, and titania surface-treated with 40% by weight of methyltrimethoxysilane. a was obtained. Evaluation was performed in the same manner as in Example 1 except that the above silica a and titania a were used.

Comparative Example 1 Evaluation was made in the same manner as in Example 1 except that the viscosity average molecular weight of the polycarbonate resin used for the charge transfer layer of the photosensitive member was changed to 20,000.

Comparative Example 2 Evaluation was made in the same manner as in Example 1 except that the viscosity average molecular weight of the polycarbonate resin used for the charge transfer layer of the photosensitive member was changed to 60,000.

Comparative Example 3 In Example 1, the composition ratio (CTM / R ratio) of the charge transfer material (CTM) to the polycarbonate (R) was 4 by weight.
Evaluation was performed in the same manner as in Example 1 except that the value was / 10.

Comparative Example 4 In Example 1, the composition ratio (CTM / R ratio) between the charge transfer material (CTM) and the polycarbonate (R) was 1 by weight.
Evaluation was performed in the same manner as in Example 1 except that the value was 1/10.

Comparative Example 5 Evaluation was made in the same manner as in Example 1 except that the addition amount of the hydrophobic inorganic fine particles was 0.03 parts by weight based on 100 parts by weight of the colored particles.

Comparative Example 6 Evaluation was made in the same manner as in Example 1 except that 2.5 parts by weight of hydrophobic inorganic fine particles were added to 100 parts by weight of the colored particles.

Comparative Example 7 Evaluation was made in the same manner as in Example 1 except that the average particle size of the primary particles of the hydrophobic inorganic fine particles was changed to 120 nm.

Comparative Example 8 In Example 1, the toner had a volume average particle diameter of 16.8 μm.
Evaluation was performed in the same manner as in Example 1 except that m was used.

<Evaluation Conditions> For each item, the image quality was evaluated after running 100,000 copies of an image chart having a 7% image area. (1) Filming properties In a high-temperature and high-humidity environment (30 ° C., 80% RH), further 5000
The filming state was visually evaluated from the surface observation of the photoreceptor after the running output of one sheet. ：: good, ×: many occurrences. (2) Amount of Depletion The film thickness of the photoreceptor drum after the running output of 100,000 sheets was measured, and the depleted film thickness was calculated from the difference from the initial value. ◎: 0.50 μm or less, ◎: 0.51 to 2.00 μm, ×: 2.01 μm or more. Image evaluation Check the image sample after running output of 100,000 sheets to see the presence or absence of image defects due to photoreceptor deterioration such as background fog, white streaks and black streaks in halftone images, unevenness in density, image density, fine line reproducibility, The vividness of the image was examined. Judging them comprehensively, those with few image defects and excellent image quality ◎,
Excellent was evaluated as O, slightly inferior as Δ, and extremely poor as X. The results are shown in Table 1.

[0099]

[Table 1]

[0100]

According to the present invention, the photoreceptor surface does not cause filming of toner or the like on the photoreceptor surface, and even if it is removed by cleaning, the photoreceptor surface is hardly worn, scarcely damaged, and does not damage the photoreceptor. A high-quality image forming method, a toner that can be used in the image forming method, and a photoconductor can be provided.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 9/087 G03G 9/08 371 9/08 371 374 374 375 375 321 333 (72) Inventor Yasutaka Iwamoto Tokyo 1-3-6 Nakamagome, Tokyo Ota-ku, Ricoh Co., Ltd. (72) Inventor Hiroshi Nakai 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (72) Inventor Hiroto Higuchi Ota-ku, Tokyo 1-3-6 Nakamagome F-term in Ricoh Co., Ltd. (Reference) 2H005 AA01 AA08 CA07 CA12 CA15 CA26 CB07 CB13 EA05 EA07 2H068 AA13 AA28 AA34 AA35 BB25 BB52 4J002 CG011 CG021 CG031 ER016 EU0EU EU EU 206

Claims (14)

[Claims] In an electrophotographic image forming method, a charge-transfer substance (CTM) and a polycarbonate (R) having a viscosity average molecular weight of 30,000 or more and 50,000 or less are used in 5/10 to 10/10 (C).
An electrophotographic photoreceptor having a charge transfer layer (TM / R weight ratio), and a toner having a volume average particle diameter of 15 μm or less as a post-treatment agent in an amount of at least 0.05 to 2.0
wt% of hydrophobic inorganic fine particles (average particle diameter of primary particles is 1
(00 nm or less). 2. In an electrophotographic image forming method, a charge transfer material (CTM) and a polycarbonate (R) having a viscosity average molecular weight of 30,000 or more and 50,000 or less are mixed in a 5/10 to 10/10 (C)
An image forming method using an electrophotographic photoreceptor having a charge transfer layer (TM / R weight ratio) and a toner having an additive release rate of 0.5 to 20%. 3. The photoreceptor is a function-separated type photoreceptor containing at least a conductive substrate, a charge generation layer, and a charge transfer layer,
The charge transfer layer has an ionization potential of 5.4 to 6.0.
3. The image forming method according to claim 1, wherein the voltage is eV. 4. The contact angle of the surface of the photoreceptor to pure water is 9
The image forming method according to claim 1, wherein the angle is 0 ° or more. 5. The charge transfer layer thickness of the photoreceptor is 10 to 35.
The image forming method according to claim 1, wherein the thickness is μm. 6. The toner according to claim 1, wherein the coverage of the toner with the hydrophobic inorganic fine particles is 30 to 150%.
The image forming method according to any one of the above. 7. The image forming method according to claim 1, wherein the hydrophobic inorganic fine particles are two or more types of inorganic fine particles having different primary particle diameters. 8. The method according to claim 1, wherein the hydrophobic inorganic fine particles are silica, titanium oxide, alumina, or hydrophobic inorganic fine particles treated with silicone oil and / or hexamethyldisilazane. 2. The image forming method according to 1., 9. A binder resin synthesized by reacting at least (a) an epoxy resin, (b) a dihydric phenol, and (c) an alkylene oxide adduct of a dihydric phenol or a glycidyl ether thereof.
The image forming method according to any one of claims 1 to 8, wherein the resin is a polyol resin having a polyoxyalkylene moiety in a main chain. 10. The method according to claim 1, further comprising the step of transferring the toner image developed on the photoconductor to a recording material, and then cleaning the toner remaining on the photoconductor with a brush and an elastic rubber blade. 10. The image forming method according to any one of 1 to 9. 11. After transferring the toner image developed on the photoreceptor to a recording material, the toner remaining on the photoreceptor is cleaned by an elastic rubber blade abutted on the photoreceptor in a counter direction. The image forming method according to claim 1, further comprising a step. 12. The image forming method according to claim 1, wherein the developing method is reversal developing. 13. A toner having a volume average particle size of 15 μm or less as a post-treatment agent in an amount of at least 0.05 to
The toner used in the image forming method according to any one of claims 1 to 12, wherein 2.0 wt% of hydrophobic inorganic fine particles (primary particles have an average particle diameter of 100 nm or less) are added. 14. A charge transfer material (CTM) and a polycarbonate (R) having a viscosity average molecular weight of 30,000 or more and 50,000 or less,
The electrophotographic photoreceptor used in the image forming method according to any one of claims 1 to 12, further comprising a charge transfer layer having a charge transfer ratio of / 10/10 to 10/10 (CTM / R weight ratio).