JP2001265167A - Electrophotographic image forming device and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic image forming device, which has a belt type electrophotographic photoreceptor having superior durability and free of image defects, such as cracks, at and under high temperature and high humidity, and image unsharpness, and is capable of dealing with downsizing by using a small-sized expansion roller for the belt type electrophotographic photoreceptor and a process cartridge. SOLUTION: The electrophotographic image forming device, having respective stages for electrostatic charging, image exposing, developing, transferring and cleaning by using the belt-type electrophotographic organic photoreceptor having resin layers on a conductive substrate is characterized, in that the resin layer existing on the extreme surface with respect to the conductive substrate among the resin layers described above contains a siloxane resin and that the diameter of at least one among the tension roller of the belt-type electrophotographic organic photoreceptor is in the range of 10 to 40 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrophotographic image forming apparatus and a process cartridge.

[0002]

2. Description of the Related Art Belt-type photoreceptors have been used for high-speed and color applications because of their flexibility and design flexibility, and their durability can be made greater than that of drum types. ing. Further, application to miniaturization by reducing the tension roller of the photosensitive belt has been proposed.

[0003] However, the belt-type photoreceptor includes a driving roller and other stresses caused by the curvature of a tension roller,
Due to the stress caused by tension at the time of driving and at rest, much more severe external force than the drum type photoreceptor is received, so the joint part of the belt type photoreceptor peels off and the photosensitive layer is liable to crack in repeated use However, as a result, there is a problem that undesirable image defects are likely to occur, and therefore, it has been difficult to employ a small-diameter tension roller in which the above problem appears more conspicuously.

In recent years, a highly durable photoreceptor using a silicone hard coat technique has been proposed. However, it is still not satisfactory in terms of durability, and there is a problem in characteristics especially under high temperature and high humidity. In the case where the photosensitive layer contains a siloxane resin, the problem tends to be noticeable. Further, small-diameter toners and spherical toners are used for high image quality and high resolution, and the transfer conditions are becoming stricter.

[0005] Therefore, there has been a demand for solving the above problems.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a belt-type electrophotographic photosensitive member which has excellent durability, has no image defects such as cracks at high temperature and high humidity, and has no image blur. An object of the present invention is to provide an electrophotographic image forming apparatus and a process cartridge capable of coping with miniaturization by using a small-diameter stretching roller for a type electrophotographic photosensitive member.

[0007]

The above objects of the present invention have been attained by the following items 1 to 14.

[0008] 1. On a conductive support, using a belt-type electrophotographic organic photoconductor having a resin layer, charging, image exposure, development, transfer, in an electrophotographic image forming apparatus having each step of cleaning, in the resin layer The resin layer located on the outermost surface with respect to the conductive support contains a siloxane resin, and at least one stretch roller of the belt-type electrophotographic organic photoreceptor has a diameter of 10 to 40 mm. An electrophotographic image forming apparatus, comprising:

[0009] 2. Using a belt-type electrophotographic organic photoreceptor having a resin layer on a conductive support, in an electrophotographic image forming apparatus having respective steps of charging, image exposure, development, transfer and cleaning, the belt-type electrophotographic organic After a toner image is formed on the photoconductor, a step of transferring the toner image to a transfer material is performed.
With respect to the conductive support, the thickness loss ΔHd (μm) of the resin layer positioned on the outermost surface per rotation is 0 ≦ Hd <1 ×
2. The electrophotographic image forming apparatus according to the item 1, wherein the value is 10 ^-5 .

[0010] 3. 3. The electrophotographic image forming apparatus as described in 1 or 2, wherein the resin layer located on the outermost surface contains a siloxane resin having a crosslinked structure.

4. 4. The electrophotographic image forming apparatus according to the item 3, wherein the resin layer located on the outermost surface contains a siloxane resin having a structural unit having charge transporting performance.

5. The electrophotographic image forming apparatus according to any one of the above items 1 to 4, wherein the resin layer contains an antioxidant.

6. 6. The electrophotographic image forming apparatus according to the item 5, wherein the antioxidant is a hindered phenol antioxidant or a hindered amine antioxidant.

7. The electrophotographic image forming apparatus according to any one of the above items 1 to 6, wherein the resin layer contains organic or inorganic fine particles.

[8] The electrophotographic image forming apparatus according to any one of the above items 1 to 7, wherein the resin layer contains colloidal silica.

9. 9. The electrophotographic image forming apparatus according to any one of items 1 to 8, wherein the number average particle diameter of the toner is 3 to 8 μm.

10. 10. The electronic device according to any one of items 1 to 9, wherein the proportion of toner particles having no corners is 50% by number or more and the number variation coefficient in the number particle size distribution is 27% or less in the whole toner. Photographic image forming device.

11. The shape factor of the toner is 1.0 to 1.6
11. The electrophotographic image forming apparatus according to any one of items 1 to 10, wherein the ratio of the toner particles in the range is 65% by number or more.

[12] When the particle size of the toner is D (μm), the natural logarithm InD is plotted on the horizontal axis, and the horizontal axis is 0.23.
A histogram showing the number-based particle size distribution divided into a plurality of classes at intervals, the relative frequency (m1) of the toner particles included in the most frequent class, and the toner particles included in the next frequent class after the most frequent class. The sum (M) with the relative frequency (m2) is 7
The electrophotographic image forming apparatus according to any one of the above items 1 to 11, wherein the content is 0% or more.

13. 3. A step of sequentially transferring a toner image formed through the steps of charging, image exposure, development, transfer, separation and cleaning to a recording material for each image forming unit using the electrophotographic image forming apparatus according to 1 or 2 above. Image forming method.

14. A belt-type electrophotographic photosensitive member used in the electrophotographic image forming apparatus according to 1 or 2, and at least one selected from the group consisting of a charging step, an image exposing step, a developing step, a transferring step, a separating step, and a cleaning step. And a process cartridge which is detachable from the main body of the electrophotographic image forming apparatus.

Hereinafter, the present invention will be described in detail. The present inventors presumed that the key point of the durability of the belt-type electrophotographic photoreceptor using the small-diameter tension roller lies in the repetitive mechanical stress on the photoreceptor under high temperature and high humidity, and made extensive studies. As a result, on a conductive support, using a belt-type electrophotographic organic photoreceptor having a resin layer, charging, image exposure, development, transfer, in an electrophotographic image forming apparatus having each step of cleaning, in the electrophotographic image forming apparatus, In, with respect to the conductive support, the resin layer located on the outermost surface contains a siloxane resin, and,
Even if a belt-type electrophotographic photosensitive member using a small-sized belt-type electrophotographic photosensitive member using a small-diameter stretch roller having a diameter of at least one of the stretching rollers of the electrophotographic photosensitive member of 10 to 40 mm has high durability, And a high quality electrophotographic image with little image blur, black spots, fog, etc. was obtained.

First, the belt type electrophotographic photosensitive member according to the present invention will be described in detail. The belt type electrophotographic photoreceptor according to the electrophotographic image forming apparatus of the present invention is an endless electrophotographic photoreceptor having a photosensitive layer on a belt type support having a polymer material or the like as a constituent component. is there. In the electrophotographic image forming apparatus of the present invention, in order to drive the belt-type electrophotographic photosensitive member, support and transport are performed using several stretching rollers including rollers, but in order to minimize the transport space. It is preferable that at least one is supported and run in a form in which it is in contact with the photosensitive layer surface.

The conductive support used for the belt-type electrophotographic photoreceptor is usually prepared by preparing a support having a polymer compound as a constituent component, and then providing a conductive layer to prepare a conductive support. I do.

As the polymer compound described above, an engineering plastic base can be used.
Although not particularly limited, for example, polyethylene terephthalate, polyethylene naphthalate, polyetherimide, polyethersulfone, polycarbonate, polyarylate, and the like are preferable polymer compounds.

The thickness of the support is preferably 50 to 120 μm from the viewpoint of rigidity and flexibility.

The conductive layer may be formed by vapor deposition or sputtering of a metal or metal oxide such as aluminum or ITO (indium tin oxide), or by mixing ITO or alumina conductive fine particles with a resin. And a conductive resin film formed by coating. The conductive support preferably has a specific resistance of 10 ³ Ωcm or less at room temperature. Further, an alumite substrate or anodized alumite may be used.

In driving the belt-type electrophotographic photosensitive member according to the present invention, at least one of the tension rollers has a diameter of 1 mm.
Although it is set to a small diameter with a very high curvature of 0 to 40 mm, the resin layer located on the outermost surface of the belt type electrophotographic photosensitive member contains a siloxane resin, and the photosensitive layer has physical durability against abrasion and peeling off As a result, the size of the electrophotographic image forming apparatus can be reduced, and the obtained electrophotographic image can be obtained with high quality without blur, black spots and fog.

The resin layer on the conductive support of the belt-type electrophotographic photosensitive member according to the present invention includes an undercoat layer, a photosensitive layer, a surface layer, and further a layer such as a charge generation layer and a charge transport layer. .

The preferred layer structure of the belt-type electrophotographic photosensitive member according to the present invention will be described. The undercoat layer (UCL) used in the electrophotographic photoreceptor according to the present invention is used to improve the adhesion between the conductive support and the photosensitive layer or to prevent charge injection from the support. Provided between the photosensitive layers, as a material of the undercoat layer, a polyamide resin, a vinyl chloride resin, a vinyl acetate resin, and a copolymer resin containing two or more of the repeating units of these resins. No. Among these undercoat resins, a polyamide resin is preferable as a resin capable of reducing an increase in residual potential due to repeated use. The thickness of the undercoat layer using these resins is preferably 0.01 to 0.5 μm.

The undercoat layer most preferably used in the present invention is an undercoat layer using a curable metal resin obtained by thermosetting an organic metal compound such as a silane coupling agent or a titanium coupling agent. The thickness of the undercoat layer using a curable metal resin is preferably 0.1 to 2 μm.

The photosensitive layer of the photoreceptor according to the present invention may have a single-layer structure in which a charge generation function and a charge transport function are provided in one layer on the undercoat layer. The layer functions as a charge generation layer (CGL) and a charge transport layer (C
(TL layer). By adopting a configuration in which functions are separated, an increase in residual potential due to repeated use can be controlled to be small, and other electrophotographic characteristics can be easily controlled according to the purpose. In the photoreceptor for negative charging, a charge generation layer (CGL) is provided on the undercoat layer, and a charge transport layer (CT) is provided thereon.
(L layer). In the case of a positively charged photoreceptor, the order of the layer configuration is opposite to that of the negatively charged photoreceptor. The most preferred photosensitive layer constitution according to the present invention is a negatively charged photosensitive member constitution having the function separation structure.

The structure of the photosensitive layer of the functionally-separated negatively charged photosensitive member will be described below. The charge generation layer is made of a charge generation material (CG
M). As other substances, a binder resin and other additives may be contained as necessary.

As the charge generation material (CGM), a known charge generation material (CGM) can be used. For example, phthalocyanine pigments, azo pigments, perylene pigments, azurenium pigments, and the like can be used. Among them, CGM that can minimize the increase in residual potential due to repeated use
Has a steric and potential structure capable of forming a stable aggregation structure between a plurality of molecules, and specifically includes CGM of a phthalocyanine pigment and a perylene pigment having a specific crystal structure. For example, Bragg angle 2θ for Cu-Kα ray
CGM such as titanyl phthalocyanine having a maximum peak at 27.2 °, and benzimidazole perylene having a maximum peak at 2θ of 12.4 have almost no deterioration due to repeated use, and the residual potential increase can be reduced.

When a binder is used as a dispersion medium for CGM in the charge generation layer, a known resin can be used as the binder, but the most preferred resin is a formal resin, a butyral resin, a silicone resin, a silicone-modified butyral resin, a phenoxy resin. Resins. The ratio between the binder resin and the charge generating substance is preferably from 20 to 600 parts by mass per 100 parts by mass of the binder resin. By using these resins, the increase in residual potential due to repeated use can be minimized. The thickness of the charge generation layer is preferably from 0.01 μm to 2 μm.

The charge transport layer contains a charge transport material (CTM) and a binder resin for dispersing the CTM to form a film.
As other substances, additives such as antioxidants may be contained as necessary.

As the charge transport material (CTM), a known charge transport material (CTM) can be used. For example, triphenylamine derivatives, hydrazone compounds, styryl compounds, benzidine compounds, butadiene compounds and the like can be used. These charge transport materials are usually dissolved in a suitable binder resin to form a layer. Among these, the CTM that can minimize the increase in residual potential due to repeated use has a high mobility and a characteristic in which the ionization potential difference with the CGM to be combined is 0.5 (eV) or less, and is preferably 0. .25 (eV) or less.

The ionization potential of CGM and CTM is measured with a surface analyzer AC-1 (manufactured by Riken Keiki Co., Ltd.).

Examples of the resin used for the charge transport layer (CTL layer) include polystyrene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, epoxy resin, polyurethane resin,
Phenolic resin, polyester resin, alkyd resin,
Polycarbonate resins, silicone resins, melamine resins, and copolymer resins containing two or more of the repeating units of these resins. In addition to these insulating resins, polymer organic semiconductors such as poly-N-vinyl carbazole may be used.

The most preferred binder for these CTLs is a polycarbonate resin. Polycarbonate resins are most preferred for improving the dispersibility and electrophotographic properties of CTM. The ratio of the binder resin to the charge transporting material is preferably from 10 to 200 parts by mass per 100 parts by mass of the binder resin. The thickness of the charge transport layer is preferably from 10 to 40 μm.

The resin layer located on the outermost surface of the conductive support of the belt-type electrophotographic photosensitive member according to the present invention will be described.

The resin layer located on the outermost surface described above contains a siloxane resin for imparting high durability to the photosensitive layer. In particular, in the electrophotographic image forming apparatus according to claim 2, the resin layer positioned on the outermost surface of the electrophotographic photosensitive member with respect to the electroconductive support has a thickness loss ΔHd per rotation of the electrophotographic photosensitive member. (Μm) is 1 × 10 ⁻⁵ or less,
Preferably, it is 0.5 × 10 ⁻⁵ or less, more preferably 0.3 × 10 ⁻⁵ or less.

The thickness loss ΔHd (μm) described above is:
It is determined by performing the abrasion test described below.

<< Thickness loss ΔH per rotation of photoreceptor
Measurement method of d (μm) >> Under normal temperature and normal humidity environment (20 ° C., 50
% RH) The hardness of the electrophotographic photosensitive member connected to the drive unit is 70 ±
1 °, rebound resilience 35 ± 1%, thickness 2 ± 0.1 (mm),
A cleaning blade with a free length of 9 ± 0.1 mm has a contact angle of 10 ± 0.5 ° in the counter direction and a bite amount of 1.5 ±.
0.25 mm, the electrophotographic photosensitive member was rotated by a drive unit at a rotation of 0.1 to 10 seconds for one rotation of 0.1 to 0.05 (mg / mg) on the electrophotographic photosensitive member. c
m ² ), the density of the developed bulk is 0.41 ± 0.
1 g / cm < ³ > and a powder having a number average particle diameter of 10 to 40 (nm) were mixed as an external additive at 1 ± 0.1 mass (%) with respect to the toner, and the volume average particle diameter was 8.5 ± 0. Clean 2 μm toner. The film thickness variation of the electrophotographic photoreceptor when the electrophotographic photoreceptor has been rotated 100,000 times or more under the above conditions was measured, and the value was divided by the number of rotations of the electrophotographic photoreceptor. The amount of film thickness loss per rotation was taken.

The siloxane resin layer described above is typically formed by applying and drying a coating composition using an organosilicon compound represented by the following general formula (1) as a raw material.
These raw materials form a condensate (oligomer) of an organosilicon compound in a hydrophilic solvent by hydrolysis and a subsequent condensation reaction. By applying and drying these coating compositions, a resin layer containing a siloxane resin having a three-dimensional network structure can be formed.

Formula (1) (R) _n -Si- (X) _{4-n In the} formula, Si represents a silicon atom, R represents an organic group in which carbon is directly bonded to the silicon atom, and X represents a hydroxyl group. Or n represents a hydrolyzable group, and n represents an integer of 0 to 3.

In the organosilicon compound represented by the general formula (1), examples of the organic group in which carbon is directly bonded to silicon represented by R include alkyl groups such as methyl, ethyl, propyl and butyl, phenyl and tolyl. , Naphthyl, aryl groups such as biphenyl, γ-glycidoxypropyl, β-
Epoxy-containing groups such as (3,4-epoxycyclohexyl) ethyl, (meth) acryloyl groups such as γ-acryloxypropyl and γ-methacryloxypropyl, γ-hydroxypropyl and 2,3-dihydroxypropyloxypropyl Hydroxyl groups, vinyl, vinyl-containing groups such as propenyl, mercapto-containing groups such as γ-mercaptopropyl, γ-
Amino-containing groups such as aminopropyl and N-β (aminoethyl) -γ-aminopropyl; γ-chloropropyl;
Examples include a halogen-containing group such as 1,1-trifluorofluoropropyl, nonafluorohexyl, and perfluorooctylethyl, and other nitro and cyano-substituted alkyl groups. Particularly, an alkyl group such as methyl, ethyl, propyl, and butyl is preferable. Examples of the hydrolyzable group for X include an alkoxy group such as methoxy and ethoxy, a halogen group, and an acyloxy group. Particularly, an alkoxy group having 6 or less carbon atoms is preferable.

The organosilicon compounds represented by the general formula (1) may be used alone or in combination of two or more. However, it is preferable that at least one of the organosilicon compounds represented by the general formula (1) used is an organosilicon compound in which n is 0 or 1.

When n is 2 or more in the specific compound of the organosilicon compound represented by the general formula (1), a plurality of Rs may be the same or different. Similarly, when n is 2 or less, a plurality of Xs may be the same or different. When two or more organosilicon compounds represented by the general formula (1) are used, R and X may be the same or different between the respective compounds.

The resin layer is preferably formed by adding colloidal silica to a composition containing the above-mentioned organosilicon compound or its hydrolytic condensate. Colloidal silica is silicon dioxide particles dispersed in a colloidal form in a dispersion medium. Colloidal silica may be added at any stage of adjusting the composition of the coating solution. Colloidal silica may be added in the form of an aqueous or alcoholic sol, or an aerosol formed in the gas phase may be directly dispersed in the coating solution according to the present invention.

In addition, metal oxides such as titania and alumina may be added in the form of sol or particles.

The colloidal silica or the tetrafunctional (n = 0) or trifunctional (n = 1) organosilicon compound imparts elasticity and rigidity to the resin layer film according to the present invention by forming a crosslinked structure or the like. When the ratio of the bifunctional organosilicon compound (n = 2) increases, the rubber elasticity increases and the hydrophobicity increases. The monofunctional organosilicon compound (n = 3) does not become a polymer but reacts with unreacted residual SiOH groups. Work to increase the hydrophobicity.

For the surface layer which is required to have high hardness and high elasticity, at least one of tetrafunctional (n = 0) or trifunctional (n = 1) of the above-mentioned organosilicon compound is used as a raw material, and elasticity and rigidity are improved. It is preferable to form a provided siloxane resin layer.

The resin layer further comprises a resin containing a siloxane resin containing a charge transporting structural unit by a condensation reaction of the compound represented by the following general formula (2) with the organosilicon compound or the condensate thereof. By reforming into a layer,
The rise in the residual potential of the resin layer can be kept small.

Formula (2) B- (R ₁ -ZH) _{m In the} formula, B represents a monovalent or polyvalent group containing a structural unit having charge transport performance, and R ₁ represents a single bond or a divalent group. Represents an alkylene group, Z represents an oxygen atom, a sulfur atom or NH, and m represents an integer of 1 to 4.

The compound represented by the general formula (2) is subjected to a condensation reaction with a hydroxyl group on the surface of colloidal silica,
The siloxane resin layer may be incorporated.

In the present invention, a siloxane-based ceramic resin layer formed by adding a metal hydroxide other than colloidal silica (for example, a hydrolyzate of each alkoxide of aluminum, titanium and zirconium) may be used.

B in the general formula (2) is a monovalent or higher valent group having a charge transporting compound structure. Here, B includes a charge transporting compound structure in (R ₁ -Z) in the general formula (2).
The compound structure excluding the H) group has charge transporting performance, or the compound of BH in which the (R ₁ -ZH) group in the general formula (2) is substituted with a hydrogen atom has charge transporting performance. Means

The above-mentioned charge transporting compound is a compound exhibiting the property of having electron or hole drift mobility. Another definition is Time-Of-Flight.
It can be defined as a compound capable of obtaining a detection current due to charge transport by a known method capable of detecting charge transport performance such as a method.

The total amount (H) of the organosilicon compound having a hydroxyl group or a hydrolyzable group, and the condensate formed from the organosilicon compound having a hydroxyl group or a hydrolyzable group, and the compound of the formula (2) ( The composition ratio in the composition (I) is preferably from 100: 3 to 50: 100 by mass, more preferably from 100: 10 to 5: 100.
0: 100.

In the present invention, colloidal silica or another metal oxide may be added, but when colloidal silica or another metal oxide (J) is added, the total amount (H) + the compound (I) It is preferable to use 1 to 30 parts by mass of (J) based on 100 parts by mass of the total component.

When the total amount (H) is used in the above range, the surface layer of the photosensitive member according to the present invention has high hardness and elasticity. Excess or deficiency of the colloidal silica component (J) has the same tendency as the total amount (H). On the other hand, when the compound (I) is used within the above range, electrophotographic characteristics such as sensitivity and residual potential characteristics are good,
The hardness of the photoconductor surface layer is high.

For forming the siloxane resin layer, it is preferable to use a condensation catalyst in order to accelerate the condensation reaction. The condensation catalyst used here may be a catalyst that has at least one of a catalyst that acts in contact with the condensation reaction and a catalyst that acts to shift the reaction equilibrium of the condensation reaction to the production system.

As a specific condensation catalyst, a known catalyst such as an acid, a metal oxide, a metal salt, or an alkylaminosilane compound which has been conventionally used for a silicone hard coat material can be used. For example, each alkali metal salt of organic carboxylic acid, nitrous acid, sulfurous acid, aluminate, carbonic acid and thiocyanic acid, organic amine salt (tetramethylammonium hydroxide, tetramethylammonium acetate), tin organic acid salt (stannas octoate, Dibutyltin diacetate, dibutyltin dilaurate, dibutyltin mercaptide, dibutyltin thiocarboxylate, dibutyltin malate, etc.).

In the general formula (2), as the group having a charge transporting compound structure represented by B, there are a hole transport type and an electron transport type. The hole transport type is oxazole, oxadiazole, thiazole, triazole, imidazole,
Groups containing structural units such as imidazolone, imidazoline, bisimidazolidine, styryl, hydrazone, benzidine, pyrazoline, triarylamine, oxazolone, benzothiazole, benzimidazole, quinazoline, benzofuran, acridine, phenazine and groups derived from these derivatives. Is mentioned. On the other hand, the electron transport type includes succinic anhydride, maleic anhydride, phthalic anhydride, pyromellitic anhydride, melitic anhydride, tetratocyanoethylene, tetratocyanoquinodimethane, nitrobenzene, dinitrobenzene, trinitrobenzene, tetranitrobenzene, and nitrobenzene. Benzonitrile, picryl chloride,
Quinone chlorimide, chloranil, bromanyl, benzoquinone, naphthoquinone, diphenoquinone, tropoquinone, anthraquinone, 1-chloroanthraquinone, dinitroanthraquinone, 4-nitrobenzophenone, 4,
4'-dinitrobenzophenone, 4-nitrobenzalmalone dinitrile, α-cyano-β- (p-cyanophenyl) -2- (p-chlorophenyl) ethylene, 2,7-
Dinitrofluorenone, 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitrofluorenone,
9-fluoronylidenedicyanomethylenemalonitrile,
Polynitro-9-fluoronylidenedicyanomethylenemalonitrile, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, 3,5-dinitrobenzoic acid, perfluorobenzoic acid, 5-nitrosalicylic acid, 3,5-dinitro Examples include groups containing chemical structural units such as salicylic acid, phthalic acid and melitic acid, and groups derived from derivatives thereof, but are not limited to these structures.

Examples of typical compounds represented by the general formula (2) are shown below. Examples of compounds in which Z is an oxygen atom in the general formula (2) are shown below.

[0067]

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[0068]

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[0069]

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[0070]

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[0071]

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Next, in the general formula (2), examples of compounds in which Z is an NH group are shown below.

[0073]

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Next, in the general formula (2), examples of compounds in which Z is a mercapto group (SH) are shown below.

[0075]

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The most preferred compound represented by the following formula (2) is a compound wherein Z is a hydroxyl group (OH) and m is 2 or more. Compounds in which Z is a hydroxyl group (OH) and m is 2 or more form a resin layer having high hardness and a small increase in residual potential by the compound reacting with the organosilicon compound and entering the siloxane resin network structure. Can be formed.

Although the most preferred layer configuration of the photoreceptor according to the present invention has been described above, other layer configurations of the photoreceptor may be used in the present invention. For example, if a resin layer containing a siloxane resin containing a structural unit having a charge transporting property is applied to the charge transporting layer, it is possible to remove the surface layer of the above-described photoconductor layer configuration. When a resin layer containing a siloxane resin containing a structural unit having a charge transporting property is applied to a photosensitive layer having a single layer structure, an undercoat layer and a photosensitive layer having a single layer structure are formed on a cylindrical conductive support. The electrophotographic photosensitive member of the present invention can be formed from one resin layer.

The surface layer of the electrophotographic photosensitive member according to the present invention preferably has a contact angle with water of 90 ° or more. By setting the contact angle with water to 90 ° or more, filming of paper powder and toner fine powder can be further reduced.

As a method for increasing the contact angle of water with the siloxane resin layer having the charge transporting property to 90 ° or more, it is effective to increase the hydrophobicity of the siloxane resin layer.
As a method for this, a method of introducing an F atom-containing group into a siloxane resin, a method of introducing a dimethylsiloxane skeleton, a method of introducing an aromatic group, or a water-repellent PT
A method of adding resin particles such as FE or an organic polymer may be used.

Next, the organic particles and inorganic particles which can be used in combination with the above-mentioned colloidal silica in the resin layer according to the present invention or can be used in place of the co-idal silica include:
The following can be mentioned.

The organic particles include, for example, silicone resin, polytetrafluoroethylene, polyvinylidene fluoride, poly (chlorotrifluoroethylene), polyvinyl fluoride,
Polytetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, polytetrafluoroethylene-propylene hexafluoride copolymer, polyethylene-ethylene trifluoride copolymer, polytetrafluoroethylene-propylene hexafluoro-per Examples thereof include fluoroalkyl vinyl ether copolymer, polyethylene, polyvinyl chloride, metal stearate, polymethyl methacrylate, and melamine. The volume average particle diameter is preferably 0.01 to 5 μm, more preferably 0.05 to 5 μm. 3 μm. The amount of the organic particles contained in the resin layer according to the present invention is preferably 0.1 to 100% by mass, more preferably 1 to 50% by mass, based on the binder resin of the resin layer. If the amount is less than 1%, sufficient printing durability and lubricity cannot be imparted to the photosensitive layer, so that cleaning failure tends to occur during image formation, and the adhesion to the lower layer is not improved. If it exceeds 100% by mass, the photosensitivity of the photoreceptor decreases, and fogging is likely to occur.

As the inorganic particles, metal oxides
For example, magnesium oxide, calcium oxide, titanium oxide, zirconium oxide, tin oxide, aluminum oxide,
Examples include silicon oxide (silica), indium oxide, beryllium oxide, lead oxide, bismuth oxide, and the like. Examples of the nitride include boron nitride, aluminum nitride, and silicon nitride. Silicon, boron carbide and the like can be mentioned. The above-mentioned inorganic particles may be preferably subjected to a hydrophobizing treatment using a hydrophobizing agent such as a titanium coupling agent, a silane coupling agent, an aluminum coupling agent, or a high-molecular fatty acid.

The above-mentioned inorganic particles preferably have a volume average particle diameter of 0.01 to 5 μm, more preferably 0.05 to 5 μm.
３3 μm. The amount of the inorganic particles contained in the photoconductor surface layer is preferably 0.1 to 100% by mass, more preferably 1 to 50% by mass, based on the binder resin of the surface layer.
When the amount is less than 0.1%, sufficient printing durability, mechanical strength, or adhesiveness to the lower layer cannot be imparted to the surface layer of the photoreceptor. When the content exceeds 100% by mass, the surface roughness of the photoreceptor surface layer becomes large, and the cleaning member is damaged, resulting in poor cleaning.

The volume average particle size of the organic particles and the inorganic particles was measured by a laser diffraction / scattering type particle size distribution analyzer “LA”.
-700 "(manufactured by Horiba, Ltd.).

By adding an antioxidant to the surface layer of the siloxane resin, it is possible to effectively prevent an increase in residual potential and image blur.

The antioxidant is a typical antioxidant which reacts with an autoxidizable substance present in or on an electrophotographic photoreceptor under the conditions of light, heat, discharge and the like. It is a substance having the property of preventing or suppressing the action. Specifically, the following compounds may be mentioned.

(1) Radical chain inhibitor • Phenolic antioxidant (hindered phenol) • Amine antioxidant (hindered amine, diallyldiamine, diallylamine) • Hydroquinone antioxidant (2) Peroxidation Decomposers ・ Sulfur antioxidants (thioethers) ・ Phosphoric antioxidants (phosphites) Among the above antioxidants, the radical chain inhibitor of (1) is preferable, and particularly hindered phenol or Hindered amine antioxidants are preferred. Further, two or more kinds may be used in combination, for example, a combination of the hindered phenol antioxidant (1) and the thioether antioxidant (2) may be used. Further, a molecule containing the above structural unit, for example, a hindered phenol structural unit and a hindered amine structural unit in a molecule may be used.

Among the above antioxidants, hindered phenol-based and hindered amine-based antioxidants are particularly effective in preventing fog and image blurring at high temperature and high humidity.

The content of the hindered phenol or hindered amine antioxidant in the resin layer is 0.01 to 2
0% by mass is preferred. When the content is less than 0.01% by mass, there is no effect on fogging and image blur at high temperature and high humidity, and when the content is more than 20% by mass, the charge transport ability in the resin layer is reduced, and the residual potential tends to increase, In addition, a decrease in film strength occurs.

The antioxidant may be incorporated in the lower charge generation layer, charge transport layer, intermediate layer and the like, if necessary. The amount of the antioxidant added to these layers is preferably 0.01 to 20% by mass with respect to each layer.

Here, hindered phenol refers to compounds having a branched alkyl group at the ortho position to the hydroxyl group of the phenol compound and derivatives thereof (however, the hydroxyl group may be modified to alkoxy).

A hindered amine compound is a compound having a bulky organic group near an N atom. As the bulky organic group, there is a branched alkyl group, and for example, a t-butyl group is preferable. For example, compounds having an organic group represented by the following structural formula are preferable.

[0093]

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In the formula, R ₁₃ represents a hydrogen atom or a monovalent organic group, R _{14 to} R ₁₇ represent an alkyl group, and R ₁₈ represents a hydrogen atom, a hydroxyl group or a monovalent organic group.

As an antioxidant having a hindered phenol partial structure, for example, JP-A-1-118137 (P.
7 to P14), but the present invention is not limited thereto.

Examples of the antioxidant having a hindered amine partial structure include, for example, JP-A-1-118138 (P7-
The compounds described in P9) may also be mentioned, but the present invention is not limited thereto.

As the organic phosphorus compound, for example, there are the following compounds represented by the general formula RO-P (OR) -OR. Here, R represents a hydrogen atom, an alkyl group, an alkenyl group or an aryl group, respectively.

Examples of the organic sulfur compounds include, for example, the following compounds represented by the general formula RSR. Here, R represents a hydrogen atom, an alkyl group, an alkenyl group or an aryl group, respectively.

The following are examples of typical antioxidant compounds.

[0100]

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[0101]

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[0102]

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[0103]

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[0104]

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The following compounds are commercially available antioxidants, for example, Irganox 1076 and Irganox 101 as hindered phenols.
0, Irganox 1098, Irganox 245,
Irganox 1330, Irganox 3114, Irganox 1076, 3,5-di-t-butyl-4-
Hydroxybiphenyl, hindered amines such as SANOL LS2626, SANOL LS765, SANOL LS
770, Sanol LS744, Tinuvin 144, Tinuvin 622LD, Mark LA57, Mark LA67, Mark LA62, Mark LA68, Mark LA63, and thioethers such as Sumilizer-TPS and Sumilizer TP-D, and phosphite-based Mark 2112. , Mark PEP-8, Mark PEP-24
G, mark PEP-36, mark 329K, mark HP
-10.

In order to form a layer containing the siloxane resin according to the present invention, the siloxane resin composition is usually dissolved in a solvent and applied. Methanol as a solvent,
Alcohols such as ethanol, propanol, butanol, methyl cellosolve and ethyl cellosolve and derivatives thereof; ketones such as methyl ethyl ketone and acetone; esters such as ethyl acetate and butyl acetate are used.

The siloxane resin layer according to the present invention is preferably dried by heating. The heating promotes the crosslinking / curing reaction of the siloxane resin layer. The cross-linking and curing conditions vary depending on the type of solvent used and the presence or absence of a catalyst, but heating is preferably performed at about 60 to 160 ° C for 10 minutes to 5 hours, more preferably 90 to 120 ° C for 30 minutes to 2 hours.
Time heating is preferred.

Solvents used for dispersing and dissolving the charge generating substance and the charge transporting substance include hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as methylene chloride and 1,2-dichloroethane; methyl ethyl ketone and cyclohexanone. Ketones; esters such as ethyl acetate and butyl acetate; alcohols such as methanol, ethanol, methyl cellosolve and ethyl cellosolve and derivatives thereof; tetrahydrofuran, 1,4-dioxane and 1,3
Ethers such as dioxolane; amines such as pyridine and diethylamine; amides such as N, N-dimethylformamide; other fatty acids and phenols; one or two of sulfur and phosphorus compounds such as carbon disulfide and triethyl phosphate;
More than one species can be used.

As a coating method for producing the electrophotographic photosensitive member having the surface layer, a dip coating, a spray coating, a circular amount control type coating and the like of a coating solution can be used. In particular, in the coating process on the surface layer side of the photosensitive layer, spray coating or circular amount control type coating (a typical example is a circular slide hopper) is used to dissolve the lower layer film as much as possible and to achieve uniform coating process. Is preferred. The spray coating is described in JP-A-3-90250 and JP-A-3-269238, and the circular-amount-control type coating is described in JP-A-58-189061.

Next, a process cartridge according to the present invention will be described. In the present invention, a process cartridge which is manufactured by combining a belt-type electrophotographic photosensitive member with at least one selected from the group consisting of a charging step, an image exposure step, a development step, a transfer step, and a separation step, and is detachable. It can be.

Furthermore, the process cartridge of the present invention is
In consideration of the life of the charger portion and the case of using a non-magnetic sleeve including a magnet, it is preferable that the toner can be further added due to cost requirements. In this case, it is preferable that the magnetic particles for charging be present in the charged portion in a larger amount than the minimum required amount and circulated to further increase the durability.

Next, the structure of a color image forming apparatus using a belt-type electrophotographic photosensitive member, an image forming process, and an example of a process cartridge used for the same will be described with reference to FIGS. explain.

As the process cartridge of the present invention,
1 and 2, a photoreceptor cartridge 2 removably provided in an image forming apparatus is given as an example.

A belt-type electrophotographic photosensitive member 1 wound around an upper roller 3, a lower roller 5, a horizontal roller 7, and a pressing roller 9 in contact with the photosensitive layer surface, all of which are stretch rollers.
Is vertically stretched by the upper roller 3 and the lower roller 5, and is driven in the direction of arrow I. In addition, each of these rollers has a diameter of 22 mm.

Further, the belt-type electrophotographic photosensitive member 1 is pressed toward the closed space formed by the belt-type electrophotographic photosensitive member 1 on the surface on which the belt-type electrophotographic photosensitive member 1 moves from the bottom to the top. A pressing roller 9 is provided as guide means for guiding the electrophotographic photosensitive member 1 in the closed space direction.

A cleaning means 11 for removing the developer on the belt-type electrophotographic photosensitive member 1 is provided above the surface on which the belt-type electrophotographic photosensitive member 1 moves upward from below.

Below the cleaning means 11, a collection box 21 is provided along the belt type electrophotographic photosensitive member 1 as a collecting means for collecting the developer removed by the cleaning means 11.

Next, a latent image forming means for forming a latent image on the belt type electrophotographic photosensitive member 1 will be described. Since a four-color image forming apparatus is used as the image forming apparatus, it has four latent image forming means for each color. That is, a Y optical writing section 25Y for forming a Y (yellow) latent image on the belt-type electrophotographic photosensitive member 1 using a laser beam
An M optical writing unit 27M that forms a latent image for M (magenta) using a laser beam on the belt-type electrophotographic photosensitive member 1; A C optical writing section 29C for forming a latent image for C (cyan) and a K optical writing section 31K for forming a latent image for K (black) using a laser beam on the belt-type electrophotographic photosensitive member 1 is there.

In each of these four optical writing sections, laser light from a laser light source (not shown) is reflected by the movement of the rotation surface of the polygon mirror 37, and
Scanned, the fθ lens 39 and the cylindrical lens 4
After that, the photosensitive surface of the belt-type electrophotographic photosensitive member 1 is scanned and exposed. By this scanning exposure, an electrostatic latent image is formed on the photosensitive surface of the belt-type electrophotographic photosensitive member 1.

Next, as shown in FIGS. 1 and 3, an image forming cartridge 35 detachably provided in an image forming apparatus will be described as an example of a process cartridge according to the present invention.

In the image forming cartridge 35, four developing means for developing the electrostatic latent images of each color formed on the belt type electrophotographic photosensitive member 1 are provided. That is, a Y developing section 42Y for developing the latent image formed by the Y optical writing section 25Y, an M developing section 43M for developing the latent image formed by the M optical writing section 27M, and a C optical writing section 29C are formed. C developing unit 45C for developing the latent image that has been developed, and K developing unit 4 for developing the latent image formed by the K optical writing unit 31K.
7K.

Since the construction of these four developing units is the same,
The Y developing unit 42Y will be described, and the description of the other developing units will be omitted. Reference numerals 51 and 52 denote screws for stirring and transporting the Y developer (a developer is a two-component developer composed of a toner and a carrier) transported from a developer reservoir (not shown), and 53 a developing sleeve 55. And a supply roller for supplying the developer. The developing sleeve 55 carries a developer, reversely develops the electrostatic latent image on the belt-type electrophotographic photosensitive member 1, and forms a toner image on the belt-type electrophotographic photosensitive member 1.

Further, in the image forming cartridge 35,
Belt electrodes of charging means for applying charges to the belt-type electrophotographic photosensitive member 1 are provided corresponding to the developing units 42Y, 43M, 45C, and 47K of the respective colors. That is, the band electrode 61 for Y
A band electrode 63 for M, a band electrode 65 for C, and a band electrode 67 for K.

On the other hand, the charging means for each color of the present embodiment has grids 71, 73, 75, and 77 for controlling the charging potential on the belt-type electrophotographic photosensitive member 1. , 73, 75, and 77 are provided on the photosensitive member cartridge 2 side as shown in FIG.

In FIG. 1, reference numeral 81 denotes a paper feed unit,
Is provided in the cassette 83. The transfer paper P in the cassette 83 is conveyed out by the conveyance roller 85, nipped and conveyed by the conveyance roller pair 87 and the registration roller 88, and fed to the transfer unit 91.

The transfer section 91 includes a transfer pole 93 for transferring the developer image on the belt-type electrophotographic photosensitive member 1 to the transfer paper P by corona discharge, and a transfer sheet P from the belt-type electrophotographic photosensitive member 1 by AC discharge. And a separation pole 95 for separating the two.

Reference numeral 100 denotes a heat roller pair 101 which is
A fixing unit that applies heat and pressure to the transfer sheet P to fuse the toner to the transfer sheet P. Reference numeral 110 denotes a pair of conveyance rollers that pinch and convey the transfer sheet P that has been thermally fixed to a discharge tray 111.

Reference numeral 120 denotes a paper feed path through which transfer paper P of another size conveyed from a paper feed unit provided outside the apparatus passes.

Next, the operation of the above configuration will be described. When the belt-type electrophotographic photosensitive member 1 is driven in the direction of arrow I, first, a predetermined charging potential is applied to the belt-type electrophotographic photosensitive member 1 by the charging means for Y including the band electrode 61 and the grid 71.

Next, an electrostatic latent image is formed on the belt-type electrophotographic photosensitive member 1 by the Y optical writing section 25Y. Then, the toner in the developer carried on the developing sleeve 55 of the Y developing section 42Y moves onto the belt-type electrophotographic photosensitive member 1 by Coulomb force, and a toner image is formed on the belt-type electrophotographic photosensitive member 1. .

The same operation is performed for the remaining colors, that is, M,
The process is performed for C and K to form Y, M, C, and K toner images on the belt-type electrophotographic photosensitive member 1.

On the other hand, the transfer paper P is conveyed from the paper supply unit 81 to the transfer unit 91 by the conveyance roller 85 and the conveyance roller pair 87.

The fed transfer paper P is transferred to the registration rollers 8.
8, the timing is adjusted with respect to the toner image on the belt-type electrophotographic photosensitive member 1, and then synchronously fed to the transfer unit 91, charged by the transfer pole 93 of the transfer unit 91, and The upper developer image is transferred to the transfer paper P.

Further, the transfer paper P is separated from the belt-type electrophotographic photosensitive member 1 by the charge eliminating action of the separation pole 95.

Next, the transfer sheet P is heated and pressed by the fixing unit 100, the toner is fused to the transfer sheet P, and is discharged onto the discharge tray 111 by the pair of transport rollers 110. or,
Excess toner on the belt-type electrophotographic photosensitive member 1 after the transfer is removed by the blade 17 of the cleaning unit 11 and stored in the collection box 21.

According to the image forming apparatus having the above structure, the cleaning means 11 for removing excess toner on the belt-type electrophotographic photosensitive member 1 is provided above the surface on which the belt-type electrophotographic photosensitive member 1 moves from bottom to top. And cleaning means 11
By providing the collection box 21 for collecting the excess toner below, the removed toner can be dropped by gravity without using the transporting means, and the mechanism can be simplified and the apparatus can be downsized. By providing the cleaning unit 11 and the collection box 21 along the belt-type electrophotographic photosensitive member 1, it is possible to prevent the heat from the fixing unit 100 from adversely affecting the belt-type electrophotographic photosensitive member 1. it can.

Further, the belt-type electrophotographic photosensitive member 1 is bent using the pressing roller 9 in the direction of the closed space formed by the belt-type electrophotographic photosensitive member 1, and a collection box 21 is provided in the space formed by the bending. As a result, the size of the apparatus can be further reduced.

If grids 71, 73, 75, and 77 having the same life as the belt-type electrophotographic photosensitive member 1 are provided in the photosensitive-member cartridge 2, the belt-type electrophotographic photosensitive member 1 can be replaced with a single operation. The grids 71, 73, 75, 77 can be replaced, and component replacement is simplified.

Further, grids 71, 73, 75, 77
Are provided on the photoreceptor cartridge 2 and grids 71 and 7 are provided.
By integrating the belts 3, 75, 77 and the belt-type electrophotographic photosensitive member 1, grids 71, 7 having strict distance accuracy are provided.
The intervals between 3, 75, 77 and the belt-type electrophotographic photosensitive member 1 can always be maintained at a constant accuracy.

Further, the developing units 42Y, 43M, 45C, 4
The band electrodes 61, 63, 65, and 6 having the same life as the life of 7K
By providing the image forming cartridge 7 in the image forming cartridge 35, the developing unit and the band electrode can be exchanged by one operation, and the parts exchange becomes easy.

Further, since the developing unit for each color and the respective band electrodes of the charging means for each color are integrated into the image forming cartridge 35, even a multicolor image forming apparatus requires only one operation. The developing section and the band electrode can be exchanged, and parts exchange becomes easy.

Note that the present invention is not limited to the above embodiment. In the above embodiment, the description has been given of a multicolor image forming apparatus, but the present invention can be applied to a monochromatic image forming apparatus.

Next, the toner and the developer according to the present invention will be described. In the present invention, an electrostatic latent image on an image carrier can be developed using either a one-component developer or a two-component developer.

The one-component developer is composed of a magnetic toner comprising at least a magnetic powder and a binder resin, and may contain a colorant.

The two-component developer is composed of toner particles (toner) and carrier particles (carrier). In the development, a DC bias of the same polarity or opposite polarity to the toner and a developing bias in which an AC voltage is superimposed on the DC voltage are applied between the developing sleeve as a developer transporting body and the photosensitive drum, and the contact or non-contact state is applied. Performed by contact.

The toner according to the present invention has a temperature of 30.degree.
The saturated water content in the H environment is preferably from 0.1 to 2.0% by mass. Specific methods for adjusting the water content include, for example, the following.

The first means is to increase the hydrophobic component of the binder resin in the toner. In the constituent components of the binder resin, the content of the strongly hydrophobic styrene component is preferably 50% by mass or more, more preferably 60% or more, and particularly preferably 70% or more based on all monomers.

As a second means, the water content of the external additive of the toner is reduced. For that purpose, it is effective to increase the degree of hydrophobicity of the external additive as described later. The degree of hydrophobicity of the external additive is 6
It is desirable to use ones with zero or more.

As a third means, it is also an effective method to increase the amount of non-polar release agent present on the surface. For this purpose, it is particularly preferable to use a polyolefin-based wax.In order to increase the amount of polyolefin present on the surface, a method of using a mechanical pulverizer to impart frictional heat at the time of crushing to bleed out to the toner surface is used. is there.

The saturated water content of the toner according to the present invention is:
Although measured by the Karl Fischer method, in the present invention, it was measured using a Hiranuma-type automatic trace moisture analyzer AQS-724. The measurement conditions were a vaporization temperature of 110 ° C. and a vaporization time of 25 seconds.

In the toner according to the present invention, the ratio of the toner particles having no corners in the toner particles constituting the toner is 5%.
It is preferably at least 0% by number, more preferably
70% by number or more.

When the ratio of the toner particles having no corners is 50% by number or more, the gap of the transferred toner layer (powder layer) is reduced, the fixing property is improved, and the offset is hardly generated. In addition, the amount of toner particles that are easily worn or broken and the number of toner particles having a portion where charges are concentrated are reduced, the charge amount distribution is sharpened, the chargeability is stabilized, and good image quality can be formed over a long period of time.

Here, “toner particles having no corner” refers to toner particles having substantially no projections on which electric charges are concentrated or projections which are easily worn by stress.
Specifically, the following toner particles are referred to as toner particles having no corners. That is, as shown in FIG.
When the major axis is L, a circle C having a radius (L / 10)
The case where the circle C does not substantially protrude outside the toner T when the inside is rolled while contacting the inside at one point with respect to the peripheral line of the toner particle T is referred to as “toner particle having no corner”. “Cases that do not substantially protrude” refer to cases where there are no more than one protrusion having a protruding circle. Also,
The “longer diameter of the toner particle” refers to the width of the particle at which the interval between the parallel lines is the largest when the projected image of the toner particle on the plane is sandwiched between two parallel lines. FIGS. 4B and 4C show projected images of toner particles having corners, respectively.

The ratio of the toner particles having no corners was measured as follows. First, a photograph in which the toner particles were enlarged by a scanning electron microscope was taken, and further enlarged to 15.0.
Obtain a 00x photographic image. Next, the presence or absence of the corners is measured for this photographic image. This measurement was performed for 100 toner particles.

The method for obtaining a toner having no corners is not particularly limited. For example, as described above, as a method of controlling the shape coefficient, a method of spraying toner particles into a hot air flow, a method of repeatedly applying mechanical energy by an impact force in a gas phase, or a method of dissolving a toner It can be obtained by adding to a solvent that does not contain and giving a swirling flow.

In a polymerization toner formed by associating or fusing resin particles, the surface of the fused particles has many irregularities at the stage of stopping the fusion, and the surface is not smooth. By setting conditions such as the temperature, the number of rotations of the stirring blade, and the stirring time, toner having no corners can be obtained. These conditions vary depending on the physical properties of the resin particles. For example, by setting the rotation speed higher than the glass transition temperature of the resin particles, the surface becomes smooth and a toner having no corners can be formed.

In the toner according to the present invention, the coefficient of variation of the shape coefficient of the toner particles is preferably 16% or less, and the number variation coefficient in the number particle size distribution of the toner particles is preferably 27% or less. In the present invention,
The “shape factor” is represented by the following equation, and indicates the degree of roundness of the toner particles.

Shape factor = ((maximum diameter / 2) ² × π) / projected area The maximum diameter means that when a projected image of a toner particle on a plane is sandwiched between two parallel lines, the distance between the parallel lines is maximum. Means the width of the particles. The projection area refers to the area of a projected image of a toner particle on a plane.

The shape factor was determined by scanning electron microscope.
A photograph in which the toner particles were magnified by a factor of 00 was taken, and then based on the photograph, "SCANNING IMAGE A
The measurement was performed by analyzing a photographic image using "NALYZER" (manufactured by JEOL Ltd.). At this time, the shape factor according to the present invention was measured using the above formula using 100 toner particles.

In the toner according to the present invention, the ratio of the toner particles having the shape factor in the range of 1.0 to 1.6 is preferably at least 65% by number, more preferably at least 70% by number. , Particularly preferably 1.2 to 1.
The ratio of the toner particles in the range of 6 is 65% by number or more, most preferably 70% by number or more.

When the proportion of the toner particles having the shape factor in the range of 1.0 to 1.6 is 65% by number or more, the packing density of the toner particles in the toner layer transferred to the transfer material is increased. As a result, the fixing property is improved, and the offset hardly occurs. Further, the toner particles are hard to be crushed, so that the contamination of the charging member is reduced, and the charging property of the toner is stabilized.

The method for controlling the shape factor is not particularly limited. For example, a method of spraying toner particles in a hot air flow, a method of repeatedly applying mechanical energy by an impact force in a gaseous phase in a gas phase, a method of adding a toner in a solvent that does not dissolve a toner and imparting a swirling flow, etc. A method of preparing toner particles having a shape factor of 1.0 to 1.6 or 1.2 to 1.6, and adding the particles to a normal toner so as to fall within the range of the present invention. is there. Also, at the stage of preparing a so-called polymerization toner, the overall shape is controlled, and the toner particles whose shape factor is adjusted to 1.0 to 1.6 or 1.2 to 1.6 are similarly added to a normal toner. There is a way to adjust.

Among the above methods, polymerization toners are preferred in that they are simple as a production method and that they have excellent surface uniformity as compared with pulverized toners.

The “coefficient of variation of the shape coefficient” of the toner according to the present invention is calculated from the following equation. Coefficient of variation of shape coefficient = (S ₁ / K) × 100 (%) In the formula, S ₁ indicates a standard deviation of shape coefficients of 100 toner particles, and K indicates an average value of the shape coefficients.

In the toner according to the present invention, the coefficient of variation of the shape factor is preferably 16% or less, and more preferably 14% or less. Coefficient of variation of shape factor is 1
When the content is 6% or less, the voids in the transferred toner layer (powder layer) are reduced, so that the fixing property is further improved, and the offset hardly occurs. Further, the charge amount distribution becomes sharper, and the image quality is improved.

In order to uniformly control the shape factor of the toner and the variation coefficient of the shape factor without extremely varying lots, resin particles (polymer particles) constituting the toner according to the present invention are prepared (polymerized). In the step of fusing the particles and controlling the shape, an appropriate process end time may be determined while monitoring the characteristics of the toner particles (colored particles) being formed.

Monitoring means that a measuring device is incorporated in-line and the process conditions are controlled based on the measurement result. That is, for example, in the case of a polymerization toner formed by incorporating measurement such as shape in-line and assembling or fusing resin particles in an aqueous medium, the shape and particle size are sequentially sampled in a process such as fusing. Is measured, and the reaction is stopped when the desired shape is obtained.

The monitoring method is not particularly limited, but may be a flow type particle image analyzer FPIA-2000.
(Manufactured by Toa Medical Electronics Co., Ltd.) can be used. This apparatus is suitable because the shape can be monitored by performing image processing in real time while passing the sample liquid. That is, using a pump etc. from the reaction field, constantly monitoring,
The shape and the like are measured, and the reaction is stopped when the desired shape and the like are obtained.

The number particle size distribution and the number variation coefficient of the toner according to the present invention are measured with a Coulter Counter TA-II or a Coulter Multisizer (manufactured by Coulter). In the present invention, an interface (manufactured by Nikkaki) for outputting a particle size distribution and a personal computer were used by using a Coulter Multisizer.
The particle size distribution and the average particle size were calculated by measuring the volume and the number of toner particles having a size of 2 μm or more by using an aperture having a size of 100 μm in the Coulter Multisizer. The number particle size distribution represents the relative frequency of the toner particles with respect to the particle size, and the number average particle size represents the median size in the number particle size distribution. The “number variation coefficient in the number particle size distribution” of the toner is calculated from the following equation.

Number variation coefficient in number particle size distribution = (S
₂ / D _n ) × 100 (%) where S ₂ represents a standard deviation in the number particle size distribution, and D _n
Indicates a number average particle size (μm).

The number variation coefficient of the toner according to the present invention is 27.
% Or less, preferably 25% or less. When the number variation coefficient is 27% or less, voids in the transferred toner layer (powder layer) are reduced, so that the fixing property is improved, and offset is less likely to occur. Further, the charge amount distribution becomes sharp, the transfer efficiency is increased, and the image quality is improved.

The method for controlling the number variation coefficient in the toner according to the present invention is not particularly limited. For example, a method of classifying toner particles by wind force can be used, but classification in a liquid is effective for further reducing the number variation coefficient. As a method of classifying in this liquid,
There is a method in which a centrifugal separator is used to control the number of rotations to separate and collect toner particles in accordance with the difference in sedimentation velocity caused by the difference in toner particle diameter.

In particular, when a toner is produced by a suspension polymerization method, a classification operation is indispensable in order to reduce the number variation coefficient in the number particle size distribution to 27% or less. In the suspension polymerization method,
Before polymerization, it is necessary to disperse the polymerizable monomer in an aqueous medium into oil droplets of a desired size as a toner. That is, mechanical shearing by a homomixer, a homogenizer, or the like is repeated on a large oil droplet of the polymerizable monomer to reduce the oil droplet to a size of about a toner particle. In the method by a gentle shear, the number and particle size distribution of the obtained oil droplets becomes broad, and therefore,
The particle size distribution of the toner obtained by polymerizing this becomes wide. For this reason, a classification operation is required.

The particle diameter of the toner according to the present invention is preferably 3 to 8 μm in number average particle diameter. Number average particle size of 3 to 8 μm
By doing so, in the fixing process, toner particles having a large adhesive force that fly and adhere to the heating member to generate an offset are reduced, and the transfer efficiency is increased to improve the halftone image quality. Etc., the image quality is improved.

The number average particle size and the particle size distribution of the toner can be measured using a Coulter Counter TA-II, a Coulter Multisizer, a SLAD1100 (a laser diffraction type particle size measuring device manufactured by Shimadzu Corporation), or the like. In the Coulter Counter TA-II and the Coulter Multisizer, the particle size distribution in the range of 2.0 to 40 μm was measured using an aperture having an aperture diameter of 100 μm.

The method for producing the toner is not particularly limited. In the pulverization classification method, pulverization may be performed while suppressing excessive pulverization during pulverization. Further, a method of repeatedly classifying may be employed. Further, as a method for producing a so-called polymerization toner, a method for producing a toner by a suspension polymerization method or a fusion method is also preferable.

Incidentally, the polymerization method can be achieved by removing fine particles by centrifugation in a dispersion of resin particles, if necessary. In any case, the object of the present invention can be achieved as long as the above-mentioned requirements of the present invention are satisfied, whether a pulverized toner or a polymerized toner.

In the toner according to the present invention, when the particle size of toner particles is D (μm), the natural logarithm InD is plotted on the horizontal axis, and the horizontal axis is divided into a plurality of classes at intervals of 0.23. In the histogram showing the particle size distribution of, the relative frequency (m ₁ ) of the toner particles included in the most frequent class and the relative frequency (m ₂ ) of the toner particles included in the class having the next highest frequency after the most frequent class The sum (M) is preferably 70% or more.

When the sum (M) of the relative frequency (m ₁ ) and the relative frequency (m ₂ ) is 70% or more, the dispersion of the particle size distribution of the toner particles is narrowed. By using this, the occurrence of selective development can be reliably suppressed.

In the present invention, the histogram showing the number-based particle size distribution is obtained by plotting the natural logarithm InD (D: particle size of individual toner particles) in a plurality of classes (0 to 0) at intervals of 0.23.
0.23: 0.23 to 0.46: 0.46 to 0.69:
0.69 to 0.92: 0.92 to 1.15: 1.15
1.38: 1.38 to 1.61: 1.61 to 1.84:
1.84 to 2.07: 2.07 to 2.30: 2.30 to
2.53: 2.53 to 2.76...) Is a histogram showing the number-based particle size distribution, which is a particle size data of a sample measured by a Coulter Multisizer according to the following conditions. Is transferred to a computer via an I / O unit, and the computer creates the program using a particle size distribution analysis program.

[Measurement Conditions] (1) Aperture: 100 μm (2) Sample preparation method: Electrolyte [ISOTON R-1
1 (manufactured by Coulter Scientific Japan)
An appropriate amount of a surfactant (neutral detergent) is added to 50 to 100 ml, and the mixture is stirred, and 10 to 20 mg of a measurement sample is added thereto. This system is prepared by subjecting it to a dispersion treatment with an ultrasonic disperser for 1 minute.

In the case of the pulverized toner, the shape factor is from 1.2 to
The ratio of the 1.6 toner particles is about 60% by number. The variation coefficient of the shape factor is about 20%. The number variation coefficient in the number particle size distribution is about 30% when the classification operation after pulverization is performed once, and it is necessary to repeat the classification operation in order to reduce the number variation coefficient to 27% or less. .

In the case of the toner obtained by the suspension polymerization method, the toner is conventionally polymerized in a laminar flow, so that substantially spherical toner particles are obtained. For example, the toner described in JP-A-56-130762 has a shape factor Is about 20% by number, the coefficient of variation of the shape factor is also about 18%, and the proportion of toner particles without corners is also about 85% by number. Further, as described above as a method of controlling the number variation coefficient in the number particle size distribution, in order to reduce the oil droplets to the size of toner particles by repeating mechanical shearing for large oil droplets of the polymerizable monomer. In addition, the distribution of oil droplet diameters is widened, and the particle size distribution of the obtained toner is wide, and the coefficient of variation in number is as large as about 32%. A classification operation is required to reduce the coefficient of variation in number.

Polymerized toners formed by associating or fusing resin particles are described in, for example, JP-A-63-1.
No. 86253, the shape factor is 1.
The ratio of toner particles of 2 to 1.6 is about 60% by number, the variation coefficient of the shape coefficient is about 18%, and the ratio of toner particles having no corner is about 44% by number. Further, the particle size distribution of the toner is wide, the coefficient of variation in number is 30%, and a classification operation is required to reduce the coefficient of variation in number.

The structure and production method of the toner used in the present invention For the production of the toner used in the present invention, the most commonly used pulverization method, that is, the binder resin and the colorant, It may be produced by kneading and pulverizing various kinds of additives to be added and then classifying it, or may be produced by synthesizing and producing resin particles containing a release agent and a colorant in a medium.

As a method of fusing in an aqueous medium, for example, JP-A-63-186253 and JP-A-63-282749.
And a method described in JP-A No. 7-146583, and a method of forming resin particles by salting out / fusion.

The resin particles used here preferably have a weight average particle size of 50 to 2,000 nm. These resin particles may be formed by any of granulation polymerization methods such as emulsion polymerization, suspension polymerization, and seed polymerization, but are preferably used. Is an emulsion polymerization method.

Hereinafter, the monomers used for producing the resin are as follows:
In any of the production methods, a conventionally known polymerizable monomer can be used. In addition, one kind or a combination of two or more kinds can be used so as to satisfy required characteristics.

The binder resin is not particularly limited, and generally known binder resins such as a styrene resin, an acrylic resin, a styrene-acryl resin, a polyester resin, a styrene-butadiene resin, and an epoxy resin can be used. Can be used.

Examples of the resin constituting the styrene resin, the acrylic resin, and the styrene-acryl resin include styrene,
o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-chlorostyrene,
3,4-dichlorostyrene, p-phenylstyrene, p
-Ethylstyrene, 2,4-dimethylstyrene, pt
-Butylstyrene, pn-hexylstyrene, pn
-Octyl styrene, pn-nonyl styrene, pn
Styrene or a styrene derivative such as decylstyrene or pn-dodecylstyrene, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-methacrylate Octyl, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, methacrylic acid ester derivatives such as dimethylaminoethyl methacrylate, methyl acrylate, ethyl acrylate, isopropyl acrylate,
N-butyl acrylate, t-butyl acrylate, isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate, phenyl acrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate And the like are specifically exemplified as monomers constituting the resin, and these can be used alone or in combination.

Examples of other specific examples of vinyl polymers include olefins such as ethylene, propylene and isobutylene, and halogenated vinyls such as vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride and vinylidene fluoride. Vinyl esters such as vinyl propionate, vinyl acetate and vinyl benzoate; vinyl ethers such as vinyl methyl ether and vinyl ethyl ether; vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl hexyl ketone; N-vinyl carbazole; N-vinyl compounds such as N-vinylindole and N-vinylpyrrolidone; vinyl compounds such as vinylnaphthalene and vinylpyridine; acrylonitrile, methacrylonitrile, acrylamide, N-butylacrylamide, N, N-dibutylacrylamide , Methacrylamide, N- methacrylamide, there are acrylic acid or methacrylic acid derivatives such as N- octadecyl acrylamide. These vinyl monomers can be used alone or in combination.

Examples of monomers for obtaining a carboxylic acid-containing polymer with a styrene-acrylic resin (vinyl resin) include acrylic acid, methacrylic acid, α-ethylacrylic acid, fumaric acid, maleic acid, and itacone. Acid, cinnamic acid,
Monobutyl maleate, monooctyl maleate, cinnamic anhydride, methyl alkenyl succinate half ester and the like can be mentioned.

Further, a crosslinking agent such as divinylbenzene, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, and triethylene glycol dimethacrylate may be added.

The polyester resin is a resin obtained by subjecting a divalent or higher carboxylic acid and a divalent or higher alcohol component to condensation polymerization. Examples of divalent carboxylic acids are maleic acid, fumaric acid, citraconic acid, itaconic acid,
Glutacoic acid, phthalic acid, isophthalic acid, terephthalic acid,
Succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, n-dodecylsuccinic acid, n-dodecenylsuccinic acid, isododecylsuccinic acid, isododecenylsuccinic acid,
Examples thereof include n-octylsuccinic acid and n-octenylsuccinic acid, and acid anhydrides thereof can also be used.

Examples of the dihydric alcohol component constituting the polyester resin include polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl)
Propane, polyoxypropylene (3.3) -2,2-
Bis (4-hydroxyphenyl) propane, polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0)-
Etherified bisphenols such as polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, ethylene glycol, Diethylene glycol, triethylene glycol,
1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,4-butenediol, neopentyl glycol, 1,5-pentane glycol, 1,6-hexane glycol, 1,4- Examples thereof include cyclohexane dimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A, bisphenol Z, and hydrogenated bisphenol A.

Examples of the polyester resin having a crosslinked structure include the following trivalent carboxylic acids, for example,
2,4-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,2
5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, 1,
2,4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, empole trimer acid, and the like. Polyhydric alcohol component, specifically, sorbitol, 1,2,3,6-
Hexane tetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,2
By adding 5-pentatriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, etc. It can also be a crosslinked polyester resin.

[0197] Examples of the coloring agent include inorganic pigments and organic pigments. Conventionally known inorganic pigments can be used. Specific inorganic pigments are exemplified below.

Examples of black pigments include furnace black, channel black, acetylene black,
Carbon black such as thermal black and lamp black, and magnetic powder such as magnetite and ferrite are also used.

These inorganic pigments can be used alone or in combination of two or more as desired. The amount of the pigment to be added is 2 to 20% by mass, preferably 3 to 15% by mass, based on the polymer.

When used as a magnetic toner, the above-mentioned magnetite can be added. In this case, from the viewpoint of imparting predetermined magnetic characteristics, 20 to 6
It is preferable to add 0% by mass.

Conventionally known organic pigments can also be used. Specific organic pigments are exemplified below.

Examples of the pigment for magenta or red include:
C. I. Pigment Red 2, C.I. I. Pigment Red 3, C.I. I. Pigment Red 5, C.I. I. Pigment Red 6, C.I. I. Pigment Red 7, C.I. I. Pigment Red 15, C.I. I. Pigment Red 16,
C. I. Pigment Red 48: 1, C.I. I. Pigment Red 53: 1, C.I. I. Pigment Red 57:
1, C.I. I. Pigment Red 122, C.I. I. Pigment Red 123, C.I. I. Pigment Red 139,
C. I. Pigment red 144, C.I. I. Pigment Red 149, C.I. I. Pigment Red 166, C.I.
I. Pigment Red 177, C.I. I. Pigment Red 178, C.I. I. Pigment Red 222 and the like.

Examples of orange or yellow pigments include C.I. I. Pigment Orange 31, C.I. I. Pigment Orange 43, C.I. I. Pigment Yellow 12,
C. I. Pigment Yellow 13, C.I. I. Pigment Yellow 14, C.I. I. Pigment Yellow 15, C.I.
I. Pigment Yellow 17, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 94, C.I. I.
Pigment Yellow 138 and the like.

Examples of the green or cyan pigments include:
C. I. Pigment Blue 15, C.I. I. Pigment Blue 15: 2, C.I. I. Pigment Blue 15: 3,
C. I. Pigment Blue 16, C.I. I. Pigment Blue 60, C.I. I. Pigment Green 7 and the like.

These organic pigments can be used alone or in combination of two or more as desired. The amount of the pigment added is 2 to 20% by mass relative to the polymer,
１５15% by weight is selected.

The colorant can be used after surface modification. As the surface modifier, a conventionally known one can be used, and specifically, a silane coupling agent, a titanium coupling agent, an aluminum coupling agent and the like can be preferably used.

A so-called external additive can be added to the toner obtained in the present invention for the purpose of improving fluidity and cleaning property. As described above, these external additives are not particularly limited, and various inorganic particles, organic particles, and lubricants can be used.

In addition to the external additive particles, a lubricant may be added to the toner as an external additive. Lubricants include, for example, zinc, aluminum, copper, magnesium of stearic acid,
Salts such as calcium, zinc, manganese, iron of oleic acid,
Metal salts of higher fatty acids such as salts of copper, magnesium and the like, salts of zinc, copper, magnesium and calcium of palmitic acid, salts of zinc and calcium of linoleic acid, and salts of zinc and calcium of ricinoleic acid. .

The addition amount of these lubricants is preferably about 0.1 to 5% by mass based on the toner. In the toner-forming step, the above-mentioned external additive may be added to the toner particles obtained above for the purpose of improving, for example, fluidity, chargeability, and cleaning properties. As a method of adding the external additive, various known mixing devices such as a Turbula mixer, a Henschel mixer, a Nauter mixer, and a V-type mixer can be used.

The toner may contain a material capable of imparting various functions as an additive for the toner, in addition to the binder resin and the colorant. Specific examples include a release agent and a charge control agent.

As the release agent, various known ones, specifically, olefin waxes such as polypropylene and polyethylene, modified products thereof, natural waxes such as carnauba wax and rice wax, fatty acid bisamides and the like can be used. Amide waxes and the like can be mentioned. It has already been mentioned that these are preferably added as release agent particles and are preferably salted out / fused together with the resin or colorant.

Similarly, various charge control agents are also known.
What can be dispersed in water can also be used. Specifically, nigrosine dyes, metal salts of naphthenic acid or higher fatty acids, alkoxylated amines,
Quaternary ammonium salt compounds, azo metal complexes, salicylic acid metal salts or metal complexes thereof.

External Additive The external additive preferably used in the toner of the present invention has a number average particle diameter of 0.05 to 0.5 μm. When the particle size of the external additive is smaller than 0.05 μm, the physical adhesion between the toner photoreceptors is not reduced, so that the transferability is reduced, and as a result, the image density is reduced. When the particle size is larger than 0.5 μm, the external additive once adhered is easily separated and released by the stress such as stirring in the developing device, so that the released amount is accumulated in the developing device and re-used in the developing device. Aggregates, becomes a nucleus during transfer, and causes transfer omission. Further, since a large amount of the released components adhere to the surface of the photoreceptor, filming on the surface of the photoreceptor easily occurs.

The amount of the external additive to be added to the toner is 0.05 to 5.0 parts by mass of the colored particles (toner before the addition of the external additive) (hereinafter, unless otherwise specified, “parts” means “parts by mass”. Is preferred, and 1.0 to 4.0 parts is particularly preferred.
If the amount is less than 0.05 part, the effect of reducing the physical adhesive force cannot be obtained, so that the transferability tends to decrease. If the amount is more than 5.0 parts, an excessive amount of the external additive is present on the toner surface, so that the toner tends to be easily separated and released due to stress such as stirring in the developing device. Therefore, the released matter is accumulated in the developing device, re-agglomerated in the developing device, and becomes a nucleus. When this is mixed into the developed toner image, transfer omission is likely to occur at the time of transfer.
Further, since a large amount of released components adhere to the surface of the photoconductor, toner filming on the surface of the photoconductor is likely to occur.

The method of controlling the state of attachment of the external additive to the colored particles is not limited, and all generally used external addition devices for fine particles and devices for fixing or fixing to the toner surface can be used. I can do it.

Specific examples of the immobilizing device include a Henschel mixer, a Lodige mixer, and TURBO SPHE.
An RE mixer or the like can be used. Among them, the Henschel mixer can be suitably used in view of the fact that the mixing and fixing of the external additives can be performed by the same apparatus, and that the stirring and mixing can be easily performed and the external heating can be easily performed.

As the mixing method at the time of the above-mentioned fixing treatment, it is desirable to carry out the treatment at a peripheral speed of the tip of the stirring blade of 5 to 50 m / s. Preferably, the treatment is performed at 10 to 40 m / s. Further, it is preferable that the external additive is uniformly adhered to the surface of the resin particles by pre-mixing. As a method of controlling the temperature, it is preferable to adjust the temperature to a required temperature by using hot water or the like from the outside.

The method for measuring the temperature is to measure the temperature of the portion where the toner flows while the toner is being stirred and mixed. In addition, it is preferable to carry out cooling and crushing steps by flowing cold water after the fixing treatment.

As a method for controlling the degree of immobilization of the external additive on the surface of the colored particles, the colored particles and the external additive are stirred and mixed under a temperature condition of Tg−20 ≦ (stirring / mixing temperature) ≦ Tg + 20. The external additive particles can be uniformly attached to the surface of the colored particles by adjusting the arbitrary time while imparting a mechanical impact force.

Here, Tg refers to the glass transition temperature of the toner or the binder resin constituting the toner. The glass transition temperature was measured using a DSC7 differential scanning calorimeter (manufactured by PerkinElmer). The measurement method is 10
The temperature was raised from 0 ° C to 200 ° C at a rate of 10 ° C / min.
After cooling from 200 ° C to 0 ° C at a rate of ° C / min to eliminate the previous history, the temperature was raised from 0 ° C to 200 ° C at a rate of 10 ° C / min, and the endothermic peak temperature of the second heat was determined and defined as Tg. When there are a plurality of endothermic peaks, the temperature of the main endothermic peak is determined by Tg
And

As the Tg of the toner or the binder resin constituting the toner, 40 to 70 ° C. is preferably used. 4
If the temperature is lower than 0 ° C., the storage stability of the toner is poor and the toner is aggregated. If it is higher than 70 ° C., it is not preferable from the viewpoint of fixing property and productivity. From the viewpoint of imparting fluidity, an external additive may be further externally added after controlling the attachment of the external additive.

The method of measuring the number average particle diameter of the external additive was observed by observation with a transmission electron microscope, and displayed by using the one measured by image analysis.

The composition of the external additive is not particularly limited, and any external additive can be used.

For example, as inorganic external additives, various inorganic oxides, nitrides, borides and the like are preferably used. For example, silica, alumina, titania, zirconia, barium titanate, aluminum titanate, strontium titanate, magnesium titanate, zinc oxide, chromium oxide, cerium oxide, antimony oxide, tungsten oxide, tin oxide, tellurium oxide, manganese oxide, Examples include boron oxide, silicon carbide, boron carbide, titanium carbide, silicon nitride, titanium nitride, boron nitride, and the like.

Further, the inorganic external additive may be subjected to a hydrophobic treatment. When performing the hydrophobic treatment, it is preferable to perform the hydrophobic treatment with a so-called coupling agent such as various titanium coupling agents and silane coupling agents, and higher fatty acid metal salts such as aluminum stearate, zinc stearate, and calcium stearate. What has been subjected to a hydrophobic treatment is preferably used.

In the case where a resin external additive is used, the composition is not particularly limited. Generally, vinyl organic external additive particles and melamine / formaldehyde condensate,
External additive particles such as polyester, polycarbonate, polyamide and polyurethane are preferred. The reason for this is that it can be easily produced by a production method such as an emulsion polymerization method or a suspension polymerization method.

Developer The toner used in the present invention may be used as a one-component developer or a two-component developer, but is preferably a two-component developer.

When the toner is used as a one-component developer, there is a method in which the toner is used as it is as a non-magnetic one-component developer. However, usually, magnetic particles having a particle diameter of about 0.1 to 5 μm are contained in toner particles. Used as a developer. As a method of containing the same, it is common to make the non-spherical particles contain the same as the coloring agent.

Further, it can be used as a two-component developer by mixing with a carrier. In this case, as the magnetic particles of the carrier, conventionally known materials such as metals such as iron, ferrite and magnetite, and alloys of these metals with metals such as aluminum and lead are used. Particularly, ferrite particles are preferable. The magnetic particles have a volume average particle size of 15
-100 μm, more preferably 25-60 μm.

The volume average particle diameter of the carrier is typically measured by a laser diffraction type particle size distribution analyzer “HELOS” equipped with a wet disperser (SYMPATIC (SYMPIC)
(ATEC)).

The carrier is preferably a carrier in which magnetic particles are further coated with a resin, or a so-called resin-dispersed carrier in which magnetic particles are dispersed in a resin. Although there is no particular limitation on the resin composition for coating, for example, an olefin resin, a styrene resin, a styrene-acrylic resin, a silicone resin, an ester resin, a fluorine-containing polymer resin, or the like is used. The resin for forming the resin dispersion type carrier is not particularly limited, and a known resin can be used.For example, a styrene acrylic resin, a polyester resin, a fluorine-based resin, a phenol resin, or the like can be used. it can.

[0232]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto.

Example 1 << Preparation of Belt-Type Photoreceptor 1 >> (Preparation of Intermediate Layer (UCL) Composition Solution) Polyamide resin (Amilan CM-8000: manufactured by Toray Industries, Inc.) 60 g Methanol 1600 ml Deposited thickness 100μm
Coated on a polyethylene terephthalate resin support of
An intermediate layer having a thickness of 0.3 μm was formed.

(Preparation of Charge Generating Layer (CGL) Composition Solution) Y-type titanyl phthalocyanine 60 g Silicon-modified butyral resin (X-40-1211: manufactured by Shin-Etsu Chemical Co., Ltd.) 700 g 2-butanone 2000 ml The above coating composition solution was mixed, The mixture was dispersed using a sand mill for 10 hours to prepare a charge generation layer coating solution. This coating solution was applied to form a charge generation layer having a thickness of 0.2 μm.

(Preparation of Charge Transport Layer (CTL) Composition Solution) Charge transport substance (D1) 200 g Bisphenol Z-type polycarbonate (Iupilon Z300: manufactured by Mitsubishi Gas Chemical Company) 300 g 1,2-dichloroethane 2000 ml

[0236]

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The above coating composition was mixed and dissolved to prepare a charge transport layer coating liquid. This coating solution was applied on the charge generation layer to form a charge transport layer having a thickness of 20 μm.

(Preparation of Protective Layer (OCL) Composition Solution) Molecular sieve 4A (Wako Pure Chemical Industries, Ltd.) was added to 10 parts by mass of a polysiloxane resin composed of 80 mol% of methylsiloxane units and 20 mol% of methyl-phenylsiloxane units. The mixture was added, left to stand for 15 hours, and dehydrated. This resin was dissolved in 10 parts by mass of toluene, and 5 parts by mass of methyltrimethoxysilane and 0.2 parts by mass of dibutyltin acetate were added thereto to form a uniform solution. To this, 6 parts by mass of dihydroxymethyltriphenylamine (exemplified compound T-1) and 0.3 parts by mass of hindered amine (2-1) were added, mixed and dissolved to prepare a protective layer coating composition.

This protective layer coating composition was applied as a protective layer having a dry film thickness of 2 μm on the above-mentioned charge transport layer.
Heat curing was performed at 20 ° C. for 1 hour to produce a belt-type photoconductor 1.

<< Preparation of Belt-Type Photoreceptor 2 >> A belt-type photoreceptor 2 was prepared in the same manner as in the preparation of the belt-type photoreceptor 1, except that the following intermediate layer was used.

(Preparation of Intermediate Layer (UCL) Composition Solution) Titanium chelate compound TC-750 (Matsumoto Pharmaceutical Co., Ltd.) 300 g Silane coupling agent KBM-503 (Shin-Etsu Chemical Co., Ltd.) 170 g 2-propanol 1500 ml Dip coating was performed and dried at 150 ° C. for 30 minutes to form an intermediate layer having a thickness of 0.5 μm.

<< Preparation of Belt-Type Photoreceptor 3 >> (Preparation of Conductive Layer (PCL) Composition Solution) Phenol resin 160 g Conductive titanium oxide 200 g Methyl cellosolve 100 ml On a polyethylene terephthalate resin support having a thickness of 100 μm on which aluminum was deposited, Prepare and apply the above composition liquid,
A conductive layer having a dry film thickness of 15 μm was formed.

(Preparation of Intermediate Layer (UCL) Composition Solution) Polyamide resin (Amilan CM-8000: manufactured by Toray Industries, Ltd.) 60 g Methanol 1600 ml 1-butanol 400 ml The above intermediate layer composition solution was applied on the conductive layer to form a film. 1.
An intermediate layer of 0 μm was formed.

(Preparation of Charge Generating Layer (CGL) Composition Solution) Y-type titanyl phthalocyanine 60 g Silicone resin solution (KR5240, 15% xylene-butanol solution: manufactured by Shin-Etsu Chemical Co., Ltd.) 700 g 2-butanone 2000 ml The mixture was dispersed using a sand mill for 10 hours to prepare a charge generation layer composition liquid. This composition was applied on the intermediate layer to form a charge generation layer having a thickness of 0.2 μm.

(Preparation of Charge Transport Layer (CTL) Composition Liquid) Charge transport substance (D1) 200 g Bisphenol Z-type polycarbonate (Iupilon Z300: manufactured by Mitsubishi Gas Chemical Company) 300 g 1,2-dichloroethane 2000 ml Coated on the generating layer, thickness 20
A μm charge transport layer was formed.

(Preparation of Protective Layer (OCL) Composition Solution)
Molecular sieve 4A was added to 10 parts by mass of a polysiloxane resin composed of 80 mol% of methylsiloxane units and 20 mol% of methyl-phenylsiloxane units on the TL,
It was left for 15 hours and dehydrated. Toluene 10
The mixture was dissolved in 5 parts by mass, and 5 parts by mass of methyltrimethoxysilane and 0.2 parts by mass of dibutyltin acetate were added thereto to form a uniform solution.

To this, 6 parts by mass of dihydroxymethyltriphenylamine (exemplified compound T-1) and 0.3 part by mass of hindered phenol (1-3) were added and mixed, and this solution was dried to form a protective layer having a dry film thickness of 2 μm. 120 ° C,
Heat-curing was performed for one hour to produce a belt-type photoconductor 3.

<< Preparation of Belt-Type Photoreceptor 4 >> In the preparation of the belt-type photoreceptor 1, a photoreceptor coated up to CTL was placed on the photoreceptor.
To 10 parts by mass of a 1% by mass silanol group-containing methylpolysiloxane resin comprising 80 mol% of methylsiloxane units and 20 mol% of dimethylsiloxane units, was added toluene 10 parts by mass.
Dissolve in parts by mass, add molecular sieve 4A, add 1
It was left to stand for 5 hours for dehydration treatment. 5 parts by mass of methyltrimethoxysilane and 0.2 parts by mass of dibutyltin acetate were added thereto to form a uniform solution. To 100 parts by mass of this composition, 200 parts by mass of toluene, 40 parts by mass of 4- [N, N-bis (3,4-dimethylphenyl) amino]-[2- (triethoxysilyl) ethyl] benzene and hindered amine (2- 10) 0.3 parts by mass were added and mixed, and this solution was applied as a protective layer having a dry film thickness of 2 μm.
After heating for a long time, a belt-type photoconductor 4 was produced.

<< Preparation of Belt-Type Photoreceptor 5 >> In the preparation of belt-type photoreceptor 1, the same procedure was repeated except that dihydroxymethyltriphenylamine (Exemplified Compound T-1) in OCL was replaced with Exemplified Compound H-1. And belt type photoreceptor 5
Was prepared.

[0250]

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<< Preparation of Belt-Type Photoreceptor 6 >> A belt-type photoreceptor 6 was prepared in exactly the same manner as in the preparation of the belt-type photoreceptor 1, except that 5 parts by mass of colloidal silica was added to the protective layer.

<< Preparation of Belt-Type Photoreceptor 7 >> In the preparation of the belt-type photoreceptor 1, coating was performed in the same manner up to the charge generation layer. <Charge transport layer CTL> Charge transport material (exemplified compound T-1) 200 g Methyltrimethoxysilane 300 g Hindered phenol compound (1-3) 1 g Colloidal silica (30% methanol solution) 8 g 1-butanol 50 g 1% acetic acid 50 g Aluminum Tetraacetyl acetate 2 g Fluororesin particles (average particle size 1 μm) 10 g The above materials were mixed and dissolved to prepare a charge transport layer coating solution. This coating solution was applied on the charge generation layer, and 11
The resultant was cured by heating at 0 ° C. for 2 hours to form a charge transporting layer having a thickness of 12 μm.

<< Preparation of Belt-Type Photoreceptor 8 >> In the preparation of the belt-type photoreceptor 1, up to the charge transport layer was formed in the same manner. Further, the following coating composition was mixed and dissolved to prepare a coating composition for a protective layer.

(Preparation of Protective Layer (OCL) Composition Solution) Charge Transport Material (Exemplified Compound T-1) 400 g Methyltrimethoxysilane 1820 g Hindered Phenol Compound (2-1) 10 g Colloidal silica (30% methanol solution) 80 g 2 -Propanol 2250 g 2% acetic acid 1060 g aluminum tetraacetyl acetate 10 g silicone oil (methylphenyl silicone; KF-54) (Shin-Etsu Chemical Co., Ltd.) 1 g The above materials are mixed, dissolved and applied as a protective layer having a dry film thickness of 2 μm. At 110 ° C. for 1 hour to produce a belt-type photoreceptor 8.

<< Preparation of Belt-Type Photoreceptor 9 >> In the preparation of the belt-type photoreceptor 8, the methyltrimethoxysilane in the protective layer was changed to methyltrimethoxysilane and dimethyldimethoxysilane (6/4 mass ratio), and silicone oil was used. KF
A belt-type photoreceptor 9 was prepared in exactly the same manner except that -54 was replaced with X-22-160AS (silicone oil having a hydroxyl group at the end) (manufactured by Shin-Etsu Chemical Co., Ltd.).

<< Preparation of Belt-Type Photoreceptor 10 >> In preparing the belt-type photoreceptor 1, a commercially available primer P
C-7J (manufactured by Shin-Etsu Chemical Co., Ltd.) is diluted twice with toluene,
After application, dry at 100 ° C for 30 minutes, dry film thickness 0.3μ
m of the adhesive layer was formed.

Further, molecular sieve 4A was added to 10 parts by mass of a polysiloxane resin (containing 1% by mass of silanol groups) composed of 80% by mol of methylsiloxane units and 20% by mol of methyl-phenylsiloxane units.
It was left to stand for 5 hours for dehydration treatment. This resin was dissolved in 10 parts by mass of toluene, and 5 parts by mass of methyltrimethoxysilane and 0.2 parts by mass of dibutyltin acetate were added thereto to form a uniform solution.

To this, 6 parts by mass of dihydroxymethyltriphenylamine (Exemplified Compound T-1) was added and mixed, and this solution was applied as a protective layer having a dry film thickness of 1 μm.
After drying at 0 ° C. for 1 hour, a belt type photoreceptor 10 was produced.

<< Preparation of Belt-Type Photoconductor 11 (Comparative Example) >>
A belt-type photoreceptor 11 was manufactured in exactly the same manner as in the production of the belt-type photoreceptor 1 except that OCL was omitted (comparative photoreceptor)
Was prepared.

Next, a toner for image evaluation was prepared as follows. << Preparation of Toner 1 >> 100 parts of styrene-acryl resin having a mass ratio of styrene: butyl acrylate: butyl methacrylate = 75: 20: 5, carbon black 1
0 parts, low molecular weight polypropylene (number average molecular weight = 350
0) 4 parts were melted and kneaded, finely pulverized using a mechanical pulverizer, and classified by an air classifier to obtain colored particles having a number average particle size of 5.0 μm. 1.2% by mass of hydrophobic silica (hydrophobicity = 75 / number average primary particle size = 12 nm) was added to the colored particles to obtain a toner. This is referred to as “toner 1”.

<< Preparation of Toner 2 >> Styrene: butyl acrylate: butyl methacrylate: acrylic acid = 75:
100 parts of styrene-acryl resin having a mass ratio of 18: 5: 2, 10 parts of carbon black, and 4 parts of low molecular weight polypropylene (number average molecular weight = 3500) are melted and kneaded, and then finely ground using a mechanical grinder. The powder was pulverized and classified by an air classifier to obtain colored particles having a number average particle size of 6.0 μm. 1.2 mass% of hydrophobic silica (hydrophobicity = 75 / number average primary particle size = 15 nm) is added to the colored particles.
Was added to obtain a toner. This is referred to as “toner 2”.

<< Preparation of Toner 3 >> 100 parts of styrene-acryl resin having a mass ratio of styrene: butyl acrylate: methacrylic acid = 70: 20: 10, carbon black 10 parts, low molecular weight polypropylene (number average molecular weight =
4500 parts) were melted and kneaded, finely pulverized using a mechanical pulverizer, and classified by an air classifier to obtain colored particles having a number average particle size of 5.2 μm. 1.0 mass% of hydrophobic silica (degree of hydrophobicity = 75 / number average primary particle size = 13 nm) was added to the colored particles to obtain a toner. This is referred to as “toner 3”.

<< Preparation of Toner 4 >> 0.90 kg of sodium n-dodecyl sulfate and 10.0 L of pure water are added and stirred and dissolved. To this liquid, 1.20 kg of Regal 330R (carbon black manufactured by Cabot Corporation) was gradually added while stirring.
Next, continuous dispersion was performed for 20 hours using a sand grinder (medium type disperser). After the dispersion, the particle diameter of the dispersion was measured using an electrophoretic light scattering photometer ELS-800 manufactured by Otsuka Electronics Co., Ltd., and as a result, the weight average particle diameter was 122 nm. The solid content of the dispersion was 16.6% by mass, as measured by a static drying method. This dispersion is referred to as “colorant dispersion 1”.

0.055 kg of sodium dodecylbenzenesulfonate is mixed with 4.0 L of ion-exchanged water, and dissolved by stirring at room temperature. This is designated as an anionic surfactant solution A.

Nonylphenyl alkyl ether 0.01
4 kg is mixed with 4.0 L of ion-exchanged water and dissolved by stirring at room temperature. This is designated as nonionic surfactant solution A.

223.8 g of potassium persulfate is mixed with 12.0 L of ion-exchanged water and dissolved by stirring at room temperature. This is designated as initiator solution A.

A 100 L reactor equipped with a temperature sensor, a cooling pipe, and a nitrogen introducing device had a number average molecular weight (Mn) of 35.
Then, 3.41 kg of the polypropylene emulsion of No. 00, anionic surfactant solution A and nonionic surfactant solution A are added, and stirring is started. Then 44.0 L of ion exchanged water
Add. Heating is started, and when the liquid temperature reaches 75 ° C., the entire amount of the initiator solution A is added. Thereafter, the liquid temperature is reduced to 7
While controlling at 5 ° C. ± 1 ° C., 12.1 kg of styrene, 2.88 kg of n-butyl acrylate and 1.04 of methacrylic acid
kg and 548 g of t-dodecyl mercaptan. Further, the liquid temperature was raised to 80 ° C. ± 1 ° C., and the mixture was heated and stirred for 6 hours. The liquid temperature is cooled to 40 ° C. or less, and the stirring is stopped. The mixture was filtered through a pole filter, and this was mixed with latex A1
And In addition, the glass transition temperature (Tg) of the resin particles in the latex A1 was 57 ° C., the softening point was 121 ° C., and the molecular weight distribution was such that the weight average molecular weight was 127,000 and the weight average particle size was 120 nm.

200.7 g of potassium persulfate is mixed with 12.0 L of ion-exchanged water and dissolved by stirring at room temperature. this,
Initiator solution B.

The nonionic surfactant solution A is put into a 100 L reaction vessel equipped with a temperature sensor, a cooling pipe, a nitrogen introducing device, and a comb baffle, and stirring is started. Next, 44.0 L of ion-exchanged water is charged.

Heating is started, and when the liquid temperature reaches 70 ° C., an initiator solution B is added. At this time, styrene 1
1.0 kg, 4.00 kg of n-butyl acrylate, 1.04 kg of methacrylic acid, and t-dodecyl mercaptan 9.
And a solution obtained by previously mixing 02 g with the mixture. Thereafter, the mixture was heated and stirred for 6 hours while controlling the liquid temperature to 72 ° C. ± 2 ° C. Further, the liquid temperature was raised to 80 ° C. ± 2 ° C., and the mixture was heated and stirred for 12 hours. The liquid temperature is cooled to 40 ° C. or less, and the stirring is stopped. The solution was filtered through a pole filter, and the filtrate was used as latex B1. The Tg of the resin particles in latex B1 was 58 ° C., the softening point was 132 ° C., and the molecular weight distribution was such that the weight average molecular weight was 245,000 and the weight average particle size was 110 nm.

Sodium chloride as a salting-out agent was added to 5.36.
kg and 20.0 L of ion-exchanged water are added and stirred and dissolved.
This is designated as sodium chloride solution A.

The latex A1 prepared above was placed in a 100 L SUS reaction vessel equipped with a temperature sensor, a cooling pipe, a nitrogen introducing device, and a comb baffle (the stirring blade was an anchor blade).
0.0 kg, 5.2 kg of latex B1, 0.4 kg of colorant dispersion 1 and 20.0 kg of ion-exchanged water are added and stirred. Next, the mixture is heated to 35 ° C., and sodium chloride solution A is added. Thereafter, the temperature is raised after being left for 5 minutes, and the temperature is raised to a liquid temperature of 85 ° C. in 5 minutes (heating rate = 10 ° C.).
° C / min). The mixture is heated and stirred at a liquid temperature of 85 ° C. ± 2 ° C. for 6 hours to cause salting out / fusion. Thereafter, the mixture is cooled to 30 ° C. or lower and the stirring is stopped. The mixture is filtered through a sieve having an opening of 45 μm, and the filtrate is used as an association liquid (1). Then use a centrifuge,
Non-spherical particles in the form of a wet cake were collected by filtration from the associating liquid (1). Thereafter, the substrate was washed with ion-exchanged water.

The colored particles in the form of a wet cake which had been washed as described above were dried with warm air at 40 ° C. to obtain colored particles. The number average particle size of the colored particles was 7.1 μm. Further, 1.0% by mass of hydrophobic silica (hydrophobicity = 65, number average primary particle size = 12 nm) is added to the colored particles,
"Toner 4" was obtained.

<< Preparation of Toner 5 >> Coloring particles of which the particle size was changed by changing the fusing condition of the toner 4 were prepared, and the coloring particles were treated with hydrophobic silica (hydrophobicity = 65, number average primary particle size). = 12 nm) was added to give 1.0% by mass to obtain “Toner 5” having a number average particle size of 3.5 μm.

The properties of each of the toners were evaluated, and the measurement results are shown in Table 1.

[0276]

[Table 1]

<< Method of Measuring Number Average Particle Diameter of Toner >> Method of Measuring Sum of Number Distribution Relative Frequency of Toner Particles: Data of the particle diameter of each toner measured by a Coulter Multisizer are sent to a computer via an I / O unit. It was transferred and the sum M of the relative frequencies m ₁ and m ₂ was obtained in the computer.

<< Preparation of Developer >> A ferrite carrier coated with a silicone resin and having a volume average particle diameter of 45 μm was mixed with each of the above-mentioned toners, namely, toners 1 to 5, and a developer having a toner concentration of 6% was adjusted. , For evaluation. These five types of developers correspond to the toner, and
And

The number average particle size of the carrier is typically measured by a laser diffraction type particle size distribution analyzer “HELOS” equipped with a wet disperser (SYMPATIC (SYMPIC)
(ATEC)).

Subsequently, a ferrite carrier coated with a silicone resin and having a volume average particle diameter of 45 μm was mixed with each of the toners described above to prepare a developer having a toner concentration of 6%, which was used for evaluation. These developers are referred to as developers 1 to 5, respectively, corresponding to the toner.

Next, the combinations of the developer and the photoreceptor shown in Table 2 were mounted on a copying machine equipped with the belt-type electrophotographic photoreceptor shown in FIG. 1 and subjected to high temperature and high humidity (30 ° C., 80%
Under RH) conditions, the images after the initial rotation of 50,000 and 1,000,000 were evaluated. Table 2 shows the results.

The method of image evaluation is as described below. (1) Image Evaluation The image density and fog were measured using a densitometer “RD-918” (manufactured by Macbeth) for the 50,000th revolution, the image density was absolute density, and the fog was zero on paper. Measured in relative concentration. The presence or absence of image blur was visually evaluated.

A. Image density ・ ・ ・: 1.4 or more / good ・ ・ ・: 1.2 to less than 1.4 / no problem in practical use ×: less than 1.2 / impractical b. Fog ◎: less than 0.001 / good ○: 0.001 or more to less than 0.003 / no problem in practical use ×: 0.003 or more / impractical c. Image blur ◎ ・ ・ ・ 5 or less out of 50,000 sheets, good ○○ 6 to 20 out of 50,000 sheets, no practical problem × ・ ・ ・ 21 out of 50,000 sheets (2) Fine line reproducibility The line width of a line image corresponding to a 2-dot line image signal was measured by a print evaluation system "RT2000" (manufactured by Yarman Corporation).

A: Line width of first formed image (L
Both 1) and the line width (L2000) of the 2000th formed image are 200 μm or less, and the change in line width (L1−L2000) is 1 μm.
Good: 0 μm or less ○: Change in line width is 15 μm or less, and practically acceptable ×: In other cases, practically impossible (3) Evaluation of image defects and black spots The particle size and the number of black dots were measured using an image analyzer "Omnikon 3000" (manufactured by Shimadzu Corporation), and the particle size and the number of black dots were measured.
Judgment was made based on how many black spots of 0.1 mm or more per 100 cm ² .

Other large ones such as cracks and cuts were visually judged. The criterion for black spot evaluation is as follows.

A. Black spots: One black spot of 0.1 mm or more / 100 cm ²
Below, good ○: 2-3 pieces / 100 cm ² , no problem in practical use ×: 4 pieces / 100 cm ² or more, impractical b. Crack ◎ ・ ・ ・ No cracks and cracks on photoconductor ×× Many cracks and cracks (4) Difference in thickness loss of photoconductor (μm) Unused photoconductor thickness-after 1,000,000 rotations The difference in photoreceptor thickness was measured.

A method for measuring the film thickness of the electrophotographic photosensitive member according to the present invention will be described. The film thickness of the photosensitive layer is measured at random at 10 locations of uniform thickness, and the average value is defined as the film thickness of the photosensitive layer. The film thickness measuring device is an eddy current type film thickness measuring device EDDY56.
0C (HELMUT FISCHER GMBTE C
O company).

(5) Absolute value (μm) of the difference in film thickness at 3 cm from the center and the end of the photoreceptor Uneven wear (Δd (μm)) = (thickness of the center of the photoreceptor at one million rotations) -3 cm from the end of the 1 millionth rotation).

The results obtained are shown in Table 2.

[0290]

[Table 2]

In each case, no cracks or uneven wear of the photoreceptor were observed, and no fog occurred at the initial stage and after 50,000 rotations.
In addition, the density of the solid black portion was 1.4 or more in reflection density, and a high-resolution, high-quality image with no image blur, no image defects such as black spots was obtained. Further, the amount of wear of the photoconductor at the end of one million rotations was very small at 10 μm or less.

[0292]

According to the present invention, there is provided a belt-type electrophotographic photosensitive member having excellent durability, free from image defects such as cracks under high temperature and high humidity, and free from image blur. By using a small-diameter stretch roller, it was possible to provide an electrophotographic image forming apparatus and a process cartridge capable of responding to miniaturization.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of an electronic image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a configuration example of a process cartridge including a photosensitive member cartridge in FIG.

FIG. 3 is a schematic view of a configuration example of a process cartridge including an image forming cartridge in FIG.

FIG. 4A is an explanatory diagram showing a projected image of a toner particle having no corner, and FIGS. 4B and 4C are explanatory diagrams showing a projected image of a toner particle having a corner.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 belt-type electrophotographic photosensitive member 2 photosensitive member cartridge 3 upper roller 5 lower roller 7 lateral roller 9 pressing roller 11 cleaning means 35 image forming cartridge 61, 63, 65, 67 band electrode 71, 73, 75, 77 grid

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 9/08 G03G 9/08

Claims (14)

[Claims] 1. An electrophotographic image forming apparatus comprising a belt-type electrophotographic organic photoreceptor having a resin layer on a conductive support and having respective steps of charging, image exposure, development, transfer and cleaning. In the resin layer, the resin layer located on the outermost surface with respect to the conductive support contains a siloxane resin, and at least one of the stretching rollers of the belt type electrophotographic organic photoreceptor has a diameter of 10%. An electrophotographic image forming apparatus having a size of about 40 mm. 2. An electrophotographic image forming apparatus comprising a belt-type electrophotographic organic photoreceptor having a resin layer on a conductive support and having respective steps of charging, image exposure, development, transfer and cleaning. After forming a toner image on a belt-type electrophotographic organic photoconductor, a step of transferring the toner image to a transfer material is performed.
With respect to the conductive support, the thickness loss ΔHd (μm) of the resin layer positioned on the outermost surface per rotation is 0 ≦ Hd <1 ×
2. The electrophotographic image forming apparatus according to claim 1, wherein the value is 10 ^-5 . 3. The electrophotographic image forming apparatus according to claim 1, wherein the resin layer located on the outermost surface contains a siloxane resin having a crosslinked structure. 4. The electrophotographic image forming apparatus according to claim 3, wherein the resin layer located on the outermost surface contains a siloxane resin having a structural unit having charge transport performance. 5. The electrophotographic image forming apparatus according to claim 1, wherein the resin layer contains an antioxidant. 6. The electrophotographic image forming apparatus according to claim 5, wherein the antioxidant is a hindered phenol antioxidant or a hindered amine antioxidant. 7. The electrophotographic image forming apparatus according to claim 1, wherein the resin layer contains organic or inorganic fine particles. 8. The electrophotographic image forming apparatus according to claim 1, wherein the resin layer contains colloidal silica. 9. The electrophotographic image forming apparatus according to claim 1, wherein the number average particle diameter of the toner is 3 to 8 μm. 10. The toner according to claim 1, wherein the proportion of toner particles having no corners is 50% by number or more and the number variation coefficient in the number particle size distribution is 27% or less in the whole toner. 2. The electrophotographic image forming apparatus according to claim 1. 11. The toner particle according to claim 1, wherein the ratio of the toner particles having a shape factor of the toner in the range of 1.0 to 1.6 is 65% by number or more. 13. The electrophotographic image forming apparatus according to item 13. 12. When the particle size of the toner is D (μm), the natural logarithm InD is plotted on the horizontal axis, and the horizontal axis is 0.23.
A histogram showing the number-based particle size distribution divided into a plurality of classes at intervals, the relative frequency (m1) of the toner particles included in the most frequent class, and the toner particles included in the next frequent class after the most frequent class. The sum (M) with the relative frequency (m2) is 7
The electrophotographic image forming apparatus according to any one of claims 1 to 11, wherein the amount is 0% or more. 13. A toner image formed through the steps of charging, image exposure, development, transfer, separation and cleaning for each image forming unit using the electrophotographic image forming apparatus according to claim 1 or 2. An image forming method, which comprises a step of sequentially transferring to a material. 14. A group comprising: a belt-type electrophotographic photosensitive member used in the electrophotographic image forming apparatus according to claim 1; and a charging step, an image exposing step, a developing step, a transferring step, a separating step, and a cleaning step. A process cartridge made by combining at least one selected from the group consisting of: and detachable from the electrophotographic image forming apparatus main body.