JP2003029441A - Electrophotographic photoreceptor, image forming method, image forming apparatus and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor having an intermediate layer, not causing image defects such as black spots and having good potential stability in repetitive use and to provide an image forming method, an image forming apparatus and a process cartridge each using the electrophotographic photoreceptor. SOLUTION: In the electrophotographic photoreceptor having an intermediate layer between an electrically conductive support and a photosensitive layer, the intermediate layer is an insulating layer containing n-type semiconductive particles and a binder and having formed Benard convection cells.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member (hereinafter also simply referred to as a photosensitive member) used in the field of copying machines and printers, and an image forming method and image forming apparatus using the electrophotographic photosensitive member. , Process cartridges.

[0002]

2. Description of the Related Art Electrophotographic photoreceptors are mainly transferred from inorganic photoreceptors such as Se, arsenic, arsenic / Se alloys, CdS and ZnO to organic photoreceptors which are excellent in pollution and ease of manufacture. Organic photoconductors using various materials have been developed.

In recent years, function-separated type photoconductors in which different materials are responsible for charge generation and charge transport functions have become the mainstream. Among them, a laminated photoconductor in which a charge generation layer and a charge transport layer are laminated is used. Widely used.

In addition, focusing on the electrophotographic process, latent image forming methods are roughly classified into analog image forming using a halogen lamp as a light source and digital image forming using an LED or a laser as a light source. Recently, a digital latent image forming method is rapidly becoming the mainstream as a printer for a hard copy of a personal computer, and also in an ordinary copying machine because of the ease of image processing and the ease of development to a multi-function peripheral.

In digital image formation, a laser, particularly a semiconductor laser or an LED, is used as a light source when writing image information converted into a digital electric signal on a photoreceptor as an electrostatic latent image. However, in forming a latent image with a laser beam, there is known a peculiar image problem that interference fringes are generated due to reflection on the substrate surface.

In digital writing, the writing speed is slow because the exposure beam diameter is small. Therefore, a combination with reversal development is mainly used as a developing method for the exposed portion, but as a problem peculiar to the image forming method using the reversal development, toner is originally formed on a portion where an image is to be formed as a white background portion. It is known that a black spot is generated due to a local defect of the photoconductor, which is a phenomenon in which the toner adheres to cause fog.

In order to solve these problems, a technique of using an intermediate layer in the photoconductor has been developed. For example, an electrophotographic photosensitive member is known in which an intermediate layer is provided between a conductive support and a photosensitive layer, and titanium oxide particles are dispersed in a resin in the intermediate layer. Further, a technique of an intermediate layer containing titanium oxide subjected to surface treatment is also known. For example, iron oxide disclosed in JP-A-4-303846, titanium oxide surface-treated with tungsten oxide, titanium oxide surface-treated with an amino group-containing coupling agent disclosed in JP-A-9-96916, and JP-A-9-258469. Examples thereof include titanium oxide surface-treated with an organic silicon compound and titanium oxide surface-treated with methylhydrogenpolysiloxane described in JP-A-8-328283.

However, even if these techniques are used, in a severe environment of high temperature and high humidity and low temperature and low humidity, the prevention of black spots is still insufficient, or the residual potential increases due to repeated use, and the exposed portion is exposed. There is a problem that the electric potential rises and the image density cannot be sufficiently obtained.

Further, JP-A-11-344826 proposes an electrophotographic photosensitive member having an intermediate layer using a dendritic titanium oxide surface-treated with a metal oxide or an organic compound. However, according to the results of the additional test of the embodiment disclosed in this patent, the effect of preventing black spots at high temperature and high humidity and low temperature and low humidity is not sufficient.

On the other hand, in recent years, from the viewpoint of space saving and the like, there has been a demand for downsizing of electrophotographic devices such as copying machines and printers used in offices. Generally, an electrophotographic image forming apparatus has a charger, a developing device,
A transfer device, a cleaning device, a static eliminator and the like are provided. For this reason, the size of the electrophotographic image forming apparatus largely depends on the diameter of the electrophotographic photosensitive member incorporated in the apparatus. That is, in order to reduce the size of the electrophotographic image forming apparatus, it is necessary to reduce the diameter of the electrophotographic photosensitive member arranged in the central portion of the electrophotographic image forming apparatus, and it is desired to propose a photosensitive member having a small diameter. By the way, usually, the film thickness of the organic photoconductor is at least 17 μm or more, and it has been attempted to increase the dry film thickness in order to prolong the durability, that is, the life of the electrophotographic photoconductor. Since the internal stress in the layer becomes large, there is a problem that the adhesiveness with the support or the adhesiveness between the intermediate layer and the photosensitive layer deteriorates. These adhesive properties tend to decrease as the thickness of the photosensitive layer increases and the diameter of the cylindrical support decreases. Therefore, if the diameter of the electrophotographic photosensitive member is simply reduced, the photosensitive layer will be peeled off with repeated use. Especially the diameter is 5
This tendency is remarkable in a photosensitive member having a thickness of 0 mm or less.

As a method for improving the adhesiveness, conventionally, the surface of the support is roughened, an adhesive layer is provided between the photosensitive layer and the support, and the photosensitive layer is a laminate of a charge generation layer and a charge transport layer. In the case of, the method of increasing the adhesiveness of the charge generation layer is known, but there are many adverse effects such as adversely affecting the electrostatic characteristics or the photosensitive characteristics, and it has not been possible to improve the printing durability of the electrophotographic photoreceptor. Not in.

Further, Japanese Laid-Open Patent Publication No. 3-179362 mentions a method of generating a cell structure (benard cell) in the undercoat layer to roughen the surface, but there is a description that it cannot be controlled and image defects occur. is there. Japanese Patent Application Laid-Open No. 8-248651 describes that a Benard cell is generated during dip coating of an undercoat layer, resulting in deterioration of leveling property and deterioration of electrophotographic performance. In general, the occurrence of Benard cells has been regarded as unfavorable and has been reduced.

On the other hand, in JP-A-60-32056 and JP-A-60-252359, there are positively described conductive layers and intermediate layers having Benard cells, the purpose of which is to examine measures against moire. However, there is no mention of the relation with the occurrence of black spots and the effect of improving electrophotographic characteristics.

[0014]

SUMMARY OF THE INVENTION In view of the above problems of the prior art, the present invention provides a cylindrical conductive support and an intermediate layer,
An object of the present invention is to provide an electrophotographic photoreceptor having improved adhesiveness between an intermediate layer and a photosensitive layer, at the same time not causing image defects such as cracks and black spots, and having good potential stability. Another object of the present invention is to provide an image forming method, an image forming apparatus, and a process cartridge.

[0015]

Means for Solving the Problems The present inventors have used an N-type semiconductive particle-added intermediate layer and an electrophotographic photosensitive member having a Benard cell formed in the intermediate layer, whereby image defects such as black spots are generated. It has been found that a good image can be obtained for a long period of time without a decrease in image density, fogging, cracks and the like.

That is, the object of the present invention is achieved by the following configurations. 1. In an electrophotographic photoreceptor having an intermediate layer between a conductive support and a photosensitive layer, the conductive support has a surface roughness Rz of 0.2 to 2.0 μm, and the intermediate layer has N-type semiconductive particles. An electrophotographic photosensitive member comprising: an insulating layer containing a binder and a binder cell.

2. 1. The N-type semiconductor particles are subjected to surface treatment a plurality of times, and the final surface treatment is a surface treatment with a reactive organosilicon compound.
The electrophotographic photosensitive member according to 1.

3. 3. The electrophotographic photoconductor according to the item 2, wherein the reactive organosilicon compound is methylhydrogenpolysiloxane.

4. 3. The electrophotographic photoconductor according to the item 2, wherein the reactive organosilicon compound is an organosilicon compound represented by the following general formula (1).

General formula (1) R-Si- (X) ₃ (R represents an alkyl group, an aryl group, X represents a methoxy group, an ethoxy group, a halogen group) 5. 5. The electrophotographic photoconductor according to item 4, wherein R in the general formula (1) is an alkyl group having 4 to 8 carbon atoms.

6. At least one of the plurality of surface treatments is a surface treatment of one or more compounds selected from alumina, silica, and zirconia. The electrophotographic photosensitive member described.

7. 7. The electrophotographic photoreceptor according to any one of 1 to 6 above, wherein the N-type semiconductive particles have been surface-treated with an organic silicon compound having a fluorine atom.

8. 8. The electrophotographic photosensitive member according to any one of 1 to 7 above, wherein the N-type semiconductive particles are particles having a number average primary particle size of 10 nm or more and 200 nm or less.

9. 9. The electrophotographic photosensitive member according to any one of 1 to 8 above, wherein the N-type semiconductive particles are metal oxide particles.

10. 10. The electrophotographic photosensitive member described in 9 above, wherein the metal oxide particles are titanium oxide particles.

11. 11. The electrophotographic photoreceptor according to any one of 1 to 10 above, wherein the binder of the intermediate layer is a polyamide resin.

12. Dry film thickness of the intermediate layer 0.2 to 15
Any one of the above 1 to 11, characterized in that
The electrophotographic photosensitive member according to the item.

13. The surface roughness Rmax of the intermediate layer is 0.2 to 3.0 μm.
2. The electrophotographic photosensitive member according to any one of 2.

14. In an image forming method in which an electrophotographic photosensitive member is rotated and at least charging, exposure, development using a toner, and transfer are repeated, the electrophotographic photosensitive member is
3. The electrophotographic photosensitive member according to any one of 2 above, wherein the toner has a variation coefficient of shape factor of 16% or less and a variation coefficient of number in number particle size distribution of 27% or less. Image forming method.

15. The toner has a shape factor of 1.0 to
15. The image forming method as described in 14 above, which contains 65% by number or more of toner particles in the range of 1.6.

16. The toner has a shape factor of 1.2 to
16. The image forming method as described in 15 above, which contains 65% by number or more of toner particles in the range of 1.6.

17. 14. The toner according to the above 14 to 50, wherein the toner contains 50% by number or more of toner particles having no corners.
17. The image forming method according to any one of 16.

18. The number average particle diameter of the toner is 3 to 8
The image forming method as described in any one of 14 to 17 above, wherein the image forming method is μm.

19. The particle size of the toner particles is D (μm)
Where the natural logarithm InD is plotted on the horizontal axis and the horizontal axis is divided into a plurality of classes at 0.23 intervals, and the relative frequency of toner particles included in the most frequent class in the histogram showing the number-based particle size distribution (m ₁ ) And the relative frequency (m ₂ ) of the toner particles contained in the second most frequent class, the sum (M) is 70% or more.
19. The image forming method according to any one of 18 to 18.

20. 20. The image forming method described in any one of 14 to 19 above, wherein the toner is obtained from colored particles obtained by polymerizing at least a polymerizable monomer in an aqueous medium.

21. 21. The image forming method according to any one of 14 to 20, wherein the toner is obtained from colored particles obtained by associating at least resin particles in an aqueous medium.

22. 14 to 2, wherein the toner is a styrene- (meth) acrylate resin
1. The image forming method according to any one of 1.

23. 23. An image forming apparatus using the image forming method described in any one of 14 to 22.

24. 14. The electrophotographic photosensitive member according to any one of 1 to 13 above, and at least a charging unit, an image exposing unit,
A process cartridge characterized in that any one of a developing means and a cleaning means is integrally combined, and can be freely taken in and out of an image forming apparatus.

The present invention will be described in detail below. The Benard cell of the present invention means a "Benard cell (convection cell) phenomenon" that occurs in the coating layer when the coating layer is formed, and the coating layer of the intermediate layer dispersion is dried and solidified to form the intermediate layer. In the process of forming the coating layer, that is, in the process of evaporating the solvent contained in the coating layer of the intermediate layer dispersion to solidify the coating layer, the components in the coating layer convect vertically to the coating layer. And a polygonal or partially polygonal surface shape generated by applying surface tension thereto.

The present inventors utilize the above-mentioned "Benard cell (convection cell) phenomenon" occurring in the coating layer to obtain the intermediate layer, and the intermediate layer containing N-type semiconductive particles and a binder is used. We succeeded in eliminating black spots by forming Benard cells on the surface. Benard cells refer to polygonal or partially polygonal surface shapes, preferably layers containing hexagonal shapes.
In addition, the ratio of hexagons to the polygonal shape is 10 to 1
00% (number basis) is good, preferably 20-100%
Is good. Further, the size of the Benard cell is preferably about 10 to 500 μm measured at the longest part.

The size and depth of the Benard cell in the intermediate layer of the present invention can be controlled by controlling the viscosity of the intermediate layer dispersion liquid,
Surface tension, solvent composition, type, coating amount, film thickness,
This can be done by appropriately selecting the drying conditions and the like. In particular, when N-type semiconducting particles having relatively small specific gravity and surface-treated, for example, titanium oxide particles are used for the intermediate layer, they are relatively easily generated.

The intermediate layer dispersion liquid has a viscosity of 7 to 250.
The use of mPa · s is also preferable for forming a Benard cell. In this viscosity range, convection of the dispersion easily occurs due to evaporation of the solvent in the coating layer. On the other hand, when the dispersion has a high viscosity of more than 250 mPa · s or a low viscosity of less than 7 mPa · s, the solvent contained in the coating layer evaporates and the coating layer is solidified. This is because there is no possibility of convection of the dispersion liquid in the coating layer, or the degree of convection is too low, so that there is a possibility that it will not be formed.

Further, in the intermediate layer of the present invention, it is necessary to coat and dry so as to have a dry film thickness of 0.2 to 15 μm. The dry film thickness is preferably 0.3 to 10 μm
m, and more preferably 0.5 to 8 μm.

When the dry film thickness is less than 0.2 μm, the coating is used as a driving force for convection of each component in the coating layer, which is generated during the process in which the solvent contained in the coating layer is evaporated and the coating layer is solidified. The difference in surface tension and the difference in buoyancy between the upper and lower surfaces of the layer are not significant, and it becomes difficult to form a Benard cell on the surface.

If the film thickness is larger than 15 μm, the solvent in the coating layer evaporates due to forced drying in the step of drying the coating layer even after the surface of the coating layer is solidified, and foaming or cracking occurs in the layer. It becomes difficult to form the surface uniformly.

The N-type semiconducting particles used in the present invention are
A fine particle having a property of making a conductive carrier an electron is shown.
That is, the property that the conductive carrier is an electron means that the N
By including the type semiconductive particles in an insulating binder, it is possible to efficiently block the injection of holes from the substrate and to exhibit a property of not blocking electrons from the photosensitive layer.

The N-type semiconductor particles are specifically titanium oxide (TiO ₂ ), zinc oxide (ZnO), tin oxide (S).
Although fine particles such as nO ₂ ) can be used, titanium oxide is particularly preferably used in the present invention.

The average particle size of the N-type semiconductor particles used in the present invention is preferably in the range of 10 nm to 200 nm in terms of number average primary particle size, and more preferably 15 to 150 nm. When the thickness is less than 10 nm, no Benard cell is generated in the intermediate layer, and the effect of preventing black spots from being generated by the intermediate layer is small. On the other hand, if it is larger than 200 nm, the uniformity of the Benard cell is poor, and as a result, black spots also increase. An intermediate layer coating solution using N-type semiconductive particles having a number average primary particle size in the above range has good dispersion stability, and an intermediate layer formed from such a coating solution having a Benard cell is a black spot. In addition to the function of preventing generation, it has good environmental characteristics and has cracking resistance.

The number average primary particle size of the N-type semiconductor particles is
For example, in the case of titanium oxide, it is a measurement value as a Feret direction average diameter obtained by observing 100 particles as primary particles randomly by enlarging by 10,000 times by observation with a transmission electron microscope.

The N-type semiconducting particles used in the present invention may have a dendritic, needle-like, or granular shape, and the N-type semiconducting particles having such a shape are, for example, titanium oxide particles. As the crystal type, there are anatase type, rutile type, amorphous type, and the like, but any crystal type may be used, or two or more crystal types may be mixed and used. Among them, the rutile type is the best.

One of the surface treatments carried out on the N-type semiconductor particles of the present invention is that the surface treatment is carried out a plurality of times, and the last surface treatment among the plurality of surface treatments is the reactive organosilicon. The surface treatment is performed using a compound. Further, among the plurality of surface treatments, at least one surface treatment is at least one surface treatment selected from alumina, silica, and zirconia, and finally a surface treatment using a reactive organosilicon compound. Is preferably performed.

Alumina treatment, silica treatment, and zirconia treatment are treatments for precipitating alumina, silica, or zirconia on the surface of N-type semiconducting particles. Hydrates of silica, silica and zirconia are also included. Further, the surface treatment of the reactive organic silicon compound means that the reactive organic silicon compound is used in the treatment liquid.

Thus, the surface treatment of N-type semiconducting particles such as titanium oxide particles is performed at least twice, so that the surface of the N-type semiconducting particles is uniformly coated (treated). When the treated N-type semiconducting particles are used in the intermediate layer, the dispersibility of the N-type semiconducting particles such as titanium oxide particles in the intermediate layer is good and the image defects such as black spots do not occur. The photoconductor can be obtained.

Further, it is particularly preferable that the surface treatment is performed a plurality of times using alumina and silica, and then the surface treatment is performed with a reactive organic silicon compound.

The above-mentioned treatment of alumina and silica may be carried out at the same time, but especially the treatment of alumina is first carried out,
Next, it is preferable to perform silica treatment. Further, the treatment amount of alumina and silica when the treatment of alumina and silica is performed is preferably such that the amount of silica is larger than that of alumina.

The surface treatment of the N-type semiconductive particles such as titanium oxide with a metal oxide such as alumina, silica and zirconia can be carried out by a wet method. For example, silica,
Alternatively, the N-type semiconductive particles that have been subjected to the surface treatment of alumina can be produced as follows.

When titanium oxide particles are used as the N-type semiconducting particles, titanium oxide particles (number average primary particle diameter: 50 n
m) is dispersed in water at a concentration of 50 to 350 g / L to give an aqueous slurry, to which a water-soluble silicate or a water-soluble aluminum compound is added. Then, neutralize by adding an alkali or an acid, silica on the surface of the titanium oxide particles,
Alternatively, alumina is precipitated. Subsequently, filtration, washing and drying are performed to obtain the target surface-treated titanium oxide. When sodium silicate is used as the water-soluble silicate, it can be neutralized with an acid such as sulfuric acid, nitric acid or hydrochloric acid. on the other hand,
When aluminum sulfate is used as the water-soluble aluminum compound, it can be neutralized with an alkali such as sodium hydroxide or potassium hydroxide.

The amount of the metal oxide used in the surface treatment is 0.1 to 5 with respect to 100 parts by mass of N-type semiconducting particles such as titanium oxide particles in the charged amount during the surface treatment.
0 parts by weight, more preferably 1 to 10 parts by weight of metal oxide is used. Even when the above-mentioned alumina and silica are used, for example, in the case of titanium oxide particles, titanium oxide particles 10
It is preferable to use 1 to 10 parts by mass with respect to 0 parts by mass, and it is preferable that the amount of silica is larger than that of alumina.

The surface treatment with the reactive organic silicon compound, which is performed after the surface treatment with the above metal oxide, is preferably performed by the following wet method.

That is, the titanium oxide treated with the metal oxide is added to a solution prepared by dissolving or suspending the reactive organosilicon compound in an organic solvent or water, and the solution is stirred for several minutes to 1 hour. To do. Then, in some cases, the liquid is subjected to a heat treatment, subjected to a process such as filtration and then dried to obtain titanium oxide particles whose surface is coated with an organosilicon compound. The reactive organic silicon compound may be added to a suspension of titanium oxide dispersed in an organic solvent or water.

In the present invention, the surface of titanium oxide particles is coated with a reactive organosilicon compound,
Photoelectron spectroscopy (ESCA), Auger electron spectroscopy (Au)
ger), secondary ion mass spectrometry (SIMS), and diffuse reflection FI-IR.

The amount of the reactive organosilicon compound used for the surface treatment is 0 for the reactive organosilicon compound based on 100 parts by mass of titanium oxide treated with the metal oxide in the charged amount at the time of the surface treatment. 1 to 50 parts by mass, more preferably 1 to 10 parts by mass. When the amount of surface treatment is less than the above range, the surface treatment effect is not sufficiently imparted, and the dispersibility of titanium oxide particles in the intermediate layer deteriorates.
Further, if it exceeds the above range, the electric performance is deteriorated, and as a result, the residual potential increases and the charging potential decreases.

Examples of the reactive organosilicon compound used in the present invention include compounds represented by the following general formula (2). Any compound that undergoes a condensation reaction with a reactive group such as a hydroxyl group on the surface of titanium oxide can be used. However, it is not limited to the following compounds.

Formula (2) (R) _n -Si- (X) _4-n (wherein Si represents a silicon atom, R represents an organic group in which carbon is directly bonded to the silicon atom, and X represents Represents a hydrolyzable group, and n represents an integer of 0 to 3.) In the organosilicon compound represented by the general formula (2), R
As the organic group in which carbon is directly bonded to silicon represented by, methyl, ethyl, propyl, butyl, pentyl,
Alkyl groups such as hexyl, octyl and dodecyl, aryl groups such as phenyl, tolyl, naphthyl and biphenyl, γ
-Epoxy-containing groups such as glycidoxypropyl, β- (3,4-epoxycyclohexyl) ethyl, γ-acryloxypropyl, (meth) acryloyl group of γ-methacryloxypropyl, γ-hydroxypropyl, 2, Three
-Hydroxyl group containing dihydroxypropyloxypropyl,
Vinyl-containing groups such as vinyl and propenyl, mercapto-containing groups such as γ-mercaptopropyl, γ-aminopropyl, N-
Amino-containing groups such as β (aminoethyl) -γ-aminopropyl, halogen-containing groups such as γ-chloropropyl, 1,1,1-trifluoropropyl, nonafluorohexyl and perfluorooctylethyl, and other nitro and cyano A substituted alkyl group is mentioned. As the hydrolyzable group of X, an alkoxy group such as methoxy and ethoxy, a halogen group,
An acyloxy group may be mentioned.

The organosilicon compound represented by the general formula (2) may be used alone or in combination of two or more kinds.

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

The following compounds may be mentioned as examples of compounds in which n is 0. Tetrachlorosilane, diethoxydichlorosilane, tetramethoxysilane, phenoxytrichlorosilane, tetraacetoxysilane, tetraethoxysilane, tetraallyloxysilane, tetrapropoxysilane, tetraisopropoxysilane, tetrakis (2-methoxyethoxy) silane, tetrabutoxysilane , Tetraphenoxysilane, tetrakis (2-ethylbutoxy) silane, tetrakis (2-ethylhexyloxy) silane and the like.

Examples of the compound in which n is 1 include the following compounds. That is, trichlorosilane, methyltrichlorosilane, vinyltrichlorosilane, ethyltrichlorosilane, allyltrichlorosilane, n-propyltrichlorosilane, n-butyltrichlorosilane, chloromethyltriethoxysilane, methyltrimethoxysilane, mercaptomethyltrimethoxysilane, Trimethoxyvinylsilane, ethyltrimethoxysilane, 3,3,4
4,5,5,6,6,6-nonafluorohexyltrichlorosilane, phenyltrichlorosilane, 3,3,3-
Trifluoropropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, triethoxysilane, 3
-Mercaptopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 2-aminoethylaminomethyltrimethoxysilane, benzyltrichlorosilane, methyltriacetoxysilane, chloromethyltriethoxysilane, ethyltriacetoxysilane, phenyltrimethoxysilane, 3-allylthiopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-bromopropyltriethoxysilane, 3-allylaminopropyltrimethoxysilane, propyltriethoxysilane, hexyltrimethoxysilane, 3-aminopropyl Triethoxysilane, 3-methacryloxypropyltrimethoxysilane, bis (ethylmethylketoxime) methoxymethylsilane, pentyltriethoxysilane, octyl Triethoxysilane, a dodecyloxy triethoxy silane and the like.

Examples of the compound in which n is 2 include the following compounds. Dimethyldichlorosilane, dimethoxymethylsilane, dimethoxydimethylsilane, methyl-3,
3,3-trifluoropropyldichlorosilane, diethoxysilane, diethoxymethylsilane, dimethoxymethyl-3,3,3-trifluoropropylsilane, 3-chloropropyldimethoxymethylsilane, chloromethyldiethoxysilane, diethoxydimethyl Silane, dimethoxy-3-mercaptopropylmethylsilane, 3,3
4,4,5,5,6,6,6-nonafluorohexylmethyldichlorosilane, methylphenyldichlorosilane,
Diacetoxymethylvinylsilane, diethoxymethylvinylsilane, 3-methacryloxypropylmethyldichlorosilane, 3-aminopropyldiethoxymethylsilane, 3- (2-aminoethylaminopropyl) dimethoxymethylsilane, t-butylphenyldichlorosilane,
3-methacryloxypropyldimethoxymethylsilane,
3- (3-cyanopropylthiopropyl) dimethoxymethylsilane, 3- (2-acetoxyethylthiopropyl) dimethoxymethylsilane, dimethoxymethyl-2-
Piperidinoethylsilane, dibutoxydimethylsilane,
3-dimethylaminopropyldiethoxymethylsilane,
Examples include diethoxymethylphenylsilane, diethoxy-3-glycidoxypropylmethylsilane, 3- (3-acetoxypropylthio) propyldimethoxymethylsilane, dimethoxymethyl-3-piperidinopropylsilane, and diethoxymethyloctadecylsilane. To be

Examples of the compound in which n is 3 include the following compounds. Trimethylchlorosilane, methoxytrimethylsilane, ethoxytrimethylsilane, methoxydimethyl-3,3,3-trifluoropropylsilane, 3-
Chloropropylmethoxydimethylsilane, methoxy-3
-Mercaptopropylmethylmethylsilane and the like.

The organosilicon compound represented by the general formula (2) is preferably the organosilicon compound represented by the following general formula (1).

In the general formula (1) R-Si-X ₃ , R is an alkyl group, an aryl group, X is a methoxy group,
Represents an ethoxy group and a halogen group.

In the organosilicon compound represented by the general formula (1), an organosilicon compound in which R is an alkyl group having 4 to 8 carbon atoms is more preferred, and a specific preferred compound example is trimethoxy. Examples thereof include n-butylsilane, trimethoxy i-butylsilane, trimethoxyhexylsilane, and trimethoxyoctylsilane.

As a preferred reactive organosilicon compound used for the final surface treatment, a polysiloxane compound can be mentioned. The molecular weight of the polysiloxane compound is 1000.
Generally, those of up to 20000 are easily available, and the black spot prevention function is also good.

Especially when methylhydrogenpolysiloxane is used for the final surface treatment, good effects can be obtained.

Another surface treatment of titanium oxide of the present invention is titanium oxide particles which are surface-treated with an organic silicon compound having a fluorine atom. It is preferable to carry out the surface treatment with the organosilicon compound having a fluorine atom and the above-mentioned wet method.

That is, the above-mentioned organosilicon compound having a fluorine atom is dissolved or suspended in an organic solvent or water, untreated titanium oxide is added thereto, and such a solution is stirred for about several minutes to 1 hour. Then, the mixture is mixed, and if necessary subjected to heat treatment, dried through a step such as filtration to coat the titanium oxide surface with an organosilicon compound having a fluorine atom. The organosilicon compound having a fluorine atom may be added to a suspension prepared by dispersing titanium oxide in an organic solvent or water.

Incidentally, the fact that the titanium oxide surface is coated with an organic silicon compound having a fluorine atom means that
Photoelectron spectroscopy (ESCA), Auger electron spectroscopy (Au)
ger), secondary ion mass spectrometry (SIMS), and diffuse reflection FI-IR.

The organosilicon compound having a fluorine atom used in the present invention is 3,3,4,4,5,5,5.
6,6,6-nonafluorohexyltrichlorosilane,
3,3,3-trifluoropropyltrimethoxysilane, methyl-3,3,3-trifluoropropyldichlorosilane, dimethoxymethyl-3,3,3-trifluoropropylsilane, 3,3,4,4,5 , 5, 6, 6,
6-nonafluorohexyl methyl dichlorosilane etc. are mentioned.

Next, the surface-treated titanium oxide particles and other N-type semiconducting particles (hereinafter also referred to as surface-treated N-type semiconducting particles. In particular, surface-treated titanium oxide is used. The structure of the intermediate layer in which particles are also referred to as surface-treated titanium oxide) will be described.

The intermediate layer of the present invention is a conductive liquid prepared by dispersing surface-treated N-type semiconducting particles such as surface-treated titanium oxide obtained by performing the above-mentioned plurality of surface treatments in a solvent together with a binder resin. It is prepared by coating on a support.

The intermediate layer of the present invention is provided between the conductive support and the photosensitive layer, and improves the adhesiveness between the conductive support and the photosensitive layer, and has a barrier function for preventing charge injection from the support. Have. As the binder resin for the intermediate layer, a thermosetting resin such as a polyamide resin, a vinyl chloride resin, a vinyl acetate resin, a polyvinyl acetal resin, a polyvinyl butyral resin, a polyvinyl alcohol resin, a melamine resin, an epoxy resin or an alkyd resin, or a resin thereof. And a copolymer resin containing two or more of the repeating units of. Among these binder resins, a polyamide resin is particularly preferable, and an alcohol-soluble polyamide such as copolymerized or methoxymethylolated is particularly preferable.

The amount of the surface-treated N-type semiconductive particles of the present invention dispersed in the binder resin is, for example, in the case of surface-treated titanium oxide, 10 to 10,000 parts by mass relative to 100 parts by mass of the binder resin. Parts, preferably 50-1,
000 parts by mass. By using the surface-treated titanium oxide in this range, the dispersibility of the titanium oxide can be kept good, and a good intermediate layer without black spots can be formed.

Further, the intermediate layer of the present invention is substantially an insulating layer. Here, the insulating layer has a volume resistance of 1 × 10 ⁸ to 10 ¹⁵
Ω · cm. The volume resistance of the intermediate layer of the present invention is preferably 1 × 10 ⁹ to 10 ¹⁴ Ω · cm, more preferably,
2 × 10 ⁹ to 1 × 10 ¹³ Ω · cm is preferable. The volume resistance can be measured as follows.

Measurement conditions: JIS: C2318-1975
According to. Measuring instrument: Hiresta IP manufactured by Mitsubishi Petrochemical Co., Ltd. Measuring condition: Measuring probe HRS Applied voltage: 500 V Measuring environment: 20 ± 2 ° C., 65 ± 5 RH% When the volume resistance is less than 1 × 10 ⁸ , the charge blocking property of the intermediate layer decreases. However, the generation of black spots increases and the potential holding property of the electrophotographic photosensitive member also deteriorates, so that good image quality cannot be obtained. On the other hand, if it is larger than 10 ¹⁵ Ω · cm, the residual potential is likely to increase due to repeated image formation, and good image quality cannot be obtained.

The surface roughness of the intermediate layer of the present invention is preferably 0.20 to 3.00 μm in Rmax. Furthermore, 0.20
2.00 μm is preferable. If the Rmax is less than 0.2 μm, the adhesiveness between the charge generation layer and the intermediate layer becomes weak, and 3.0
If it is larger than μm, local concentration of electric charges occurs, and image defects such as black spots are likely to occur.

The coating solution for the intermediate layer prepared for forming the intermediate layer of the present invention is the surface-treated N such as the surface-treated titanium oxide.
It is composed of mold semiconductive particles, a binder resin, a dispersion solvent, and the like, and as the dispersion solvent, the same solvent as that used in the preparation of other photosensitive layers is appropriately used.

That is, the solvent or dispersion medium used to form the intermediate layer, photosensitive layer and other resin layers of the present invention is n-
Butylamine, diethylamine, ethylenediamine, isopropanolamine, triethanolamine, triethylenediamine, N, N-dimethylformamide, acetone, methylethylketone, methylisopropylketone, cyclohexanone, benzene, toluene, xylene, chloroform, dichloromethane, 1,2-dichloroethane, 1 , 2-dichloropropane, 1,1,2-trichloroethane, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethane, tetrahydrofuran, dioxolane, dioxane, methanol, ethanol, butanol, isopropanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, Methyl cellosolve and the like can be mentioned.

The solvent for the coating liquid for the intermediate layer is not limited to these, but methanol, ethanol, butanol, 1-propanol, isopropanol and the like are preferably used. Further, these solvents can be used alone or as a mixed solvent of two or more kinds.

As the solvent for coating the intermediate layer, it is preferable to use a mixed solvent of methanol and a straight-chain alcohol having high resin solubility in order to prevent uneven drying during coating of the intermediate layer. The ratio of the linear alcohol to the methanol is 1 to 0.05 by volume.
A mixture of 6 is preferable. By using the coating solvent as a mixed solvent in this way, the evaporation rate of the solvent can be appropriately maintained, and the occurrence of image defects due to uneven drying during coating can be suppressed.

As a dispersing means for the surface-treated titanium oxide used for preparing the coating solution for the intermediate layer, any dispersing means such as a sand mill, a ball mill or ultrasonic dispersing may be used.

As the coating processing method for producing the electrophotographic photosensitive member of the present invention, including the intermediate layer, dip coating,
Although coating processing methods such as spray coating and circular amount regulation type coating are used, the coating processing on the upper layer side of the photosensitive layer does not dissolve the lower layer film as much as possible, and in order to achieve uniform coating processing, spray coating or circular coating It is preferable to use a coating processing method such as regulated coating (a circular slide hopper is a typical example). Regarding the spray coating, for example, JP-A-3-
No. 90250 and JP-A-3-269238, and the circular amount control type coating is described in detail, for example, in JP-A-58-189061.

Next, the constitution of the photosensitive member preferably used in the present invention other than the intermediate layer will be described.

The photoconductor of the present invention can be applied to an inorganic photoconductor using selenium or amorphous silicon.
For the purpose of the present invention, it is preferable to apply the intermediate layer and surface layer of the present invention to an organic electrophotographic photoreceptor (also referred to as an organic photoreceptor).

In the present invention, the organic photoreceptor means an electrophotographic photoreceptor constituted by giving an organic compound at least one of a charge generating function and a charge transporting function which is indispensable for the construction of the electrophotographic photoreceptor. However, it includes all known organic electrophotographic photoreceptors such as a photoreceptor formed of a known organic charge generating material or an organic charge transporting material, and a photoreceptor including a polymer complex having a charge generating function and a charge transporting function.

The layer structure of the organic photoreceptor is not particularly limited, but a charge generation layer, a charge transport layer, or a charge generation / charge transport layer (a layer having the functions of charge generation and charge transport in the same layer).
It is preferable to adopt a constitution in which a photosensitive layer such as the above and a surface layer are coated thereon. Further, since the surface layer of the present invention has the function of a protective layer and the function of transporting charges, it may be used instead of the charge transporting layer.

The specific constitution of the photoconductor preferably used in the present invention will be described below. Conductive Support As the conductive support used in the photoreceptor of the present invention, a cylindrical conductive support is used.

The cylindrical conductive support of the present invention means a cylindrical support required to form an image endlessly by rotating, and has a straightness of 0.1 mm or less and a shake of 0.1 mm or less. Conductive supports in the range are preferred. If the straightness and the shake range are exceeded, good image formation becomes difficult.

The cylindrical conductive support used in the photoreceptor of the present invention preferably has a diameter of 10 to 300 mm, but the effect of the present invention is remarkably exhibited and the adhesion between the support and the intermediate layer is improved. At the same time, it is a photoreceptor using a cylindrical conductive support having a small diameter of 10 to 50 mm that has a remarkable effect of preventing the generation of black spots.

The conductive support of the present invention has a surface roughness Rz.
Is 0.2 to 2.0 μm. If Rz is less than 0.2 μm, the effect of improving the adhesiveness is small, and if Rz exceeds 2.0 μm, image defects such as black spots are likely to occur. The most preferable range of Rz is 0.3 to 1.8 μm.

In order to process the surface roughness of the conductive support into the above range, the surface of the support is roughened by cutting with a cutting tool, or sandblasting is performed by colliding fine particles with the surface of the support. Processing method, JP-A-4-20453
There is a method of processing with an ice particle cleaning apparatus described in No. 8 and a method of honing processing described in JP-A-9-236937. In addition, an anodizing method, an alumite treatment method, a buffing method, a laser ablation method described in JP-A-4-233546, a method using a polishing tape described in JP-A-8-1502, and The method of roller burnishing processing described in No. -1510 and the like can be mentioned. However, the method of roughening the surface of the support is not limited to these.

Definition and measuring method of surface roughness Rz and Rmax Rz and Rmax of the present invention are JIS B0601-1982.
Means the value of the reference length of 0.25 mm. That is, R
z is the difference between the average height of the top 5 peaks and the average height of the 5 bottom valleys over the distance of the reference length of 0.25 mm. On the other hand, Rmax is the difference between the maximum peak line and the maximum valley line.

In the examples described later, Rz and Rma described above are used.
x is a surface roughness meter (Surforder manufactured by Kosaka Laboratory Ltd.
SE-30H). However, another measuring device may be used as long as the measuring device produces the same result within the error range.

As the conductive material, a metal drum made of aluminum, nickel or the like, a plastic drum vapor-deposited with aluminum, tin oxide, indium oxide or the like, or a paper / plastic drum coated with a conductive substance can be used. It is preferable that the conductive support has a specific resistance of 10 ³ Ωcm or less at room temperature.

The conductive support used in the present invention may have a surface on which a sealed alumite film is formed. The alumite treatment is usually carried out in an acidic bath of chromic acid, sulfuric acid, oxalic acid, phosphoric acid, boric acid, sulfamic acid, etc., but anodizing treatment in sulfuric acid gives the most preferable result. In the case of anodizing treatment in sulfuric acid, it is preferable that the sulfuric acid concentration is 100 to 200 g / L, the aluminum ion concentration is 1 to 10 g / L, the liquid temperature is about 20 ° C., and the applied voltage is about 20 V. It is not limited. The average thickness of the anodized film is usually 2
It is preferably 0 μm or less, and particularly preferably 10 μm or less.

Intermediate Layer In the present invention, the above-mentioned intermediate layer having a barrier function is provided between the conductive support and the photosensitive layer.

Photosensitive Layer The photosensitive layer structure of the photoconductor of the present invention may be a single-layer photosensitive layer structure in which one layer has a charge generating function and a charge transporting function on the above-mentioned intermediate layer, but it is more preferable to use a photosensitive layer. It is preferable that the function of the layer is separated into a charge generation layer (CGL) and a charge transport layer (CTL). By adopting a constitution in which the functions are separated, the 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 negative charging photoreceptor, the charge generation layer (C
GL) and a charge transport layer (CTL) thereon. In the case of the photoconductor for positive charging, the order of the layers is the reverse of that of the photoconductor for negative charging. The most preferable photosensitive layer structure of the present invention is a negatively charged photosensitive member structure having the above-mentioned function separation structure.

The constitution of the photosensitive layer of the function-separated negatively charged photoreceptor will be described below. Charge Generation Layer The charge generation layer contains a charge generation material (CGM). If necessary, a binder resin and other additives may be contained as other substances.

As the charge generating substance (CGM), a known charge generating substance (CGM) can be used. For example, a phthalocyanine pigment, an azo pigment, a perylene pigment, an azurenium pigment or the like can be used. Among these, CGM that can minimize the increase in residual potential with repeated use
Has a steric structure and a potential structure capable of forming a stable aggregation structure among a plurality of molecules, and specific examples thereof include a phthalocyanine pigment and a perylene pigment CGM having a specific crystal structure. For example, the Bragg angle 2θ with respect to Cu-Kα rays
CGMs such as titanyl phthalocyanine having a maximum peak at 27.2 ° and benzimidazole perylene having a maximum peak at 22.4 at 27.2 have almost no deterioration due to repeated use, and the residual potential increase can be reduced.

When a binder is used as a CGM dispersion medium in the charge generation layer, a known resin can be used as the binder, but the most preferable resin is formal resin, butyral resin, silicone resin, silicone modified butyral resin, phenoxy resin. Resin etc. are mentioned. The ratio of the binder resin to the charge generating substance is preferably 20 to 600 parts by mass with respect to 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 0.01 μm to 2 μm.

Charge Transport Layer The charge transport layer contains a charge transport material (CTM) and a binder resin for dispersing CTM to form a film. Other substances may optionally contain additives such as antioxidants.

As the charge transport material (CTM), a known charge transport material (CTM) can be used. For example, a triphenylamine derivative, a hydrazone compound, a styryl compound, a benzidine compound, a butadiene compound or the like can be used. These charge transport materials are usually dissolved in a suitable binder resin to form a layer. Among these, CTM that can minimize the increase in residual potential due to repeated use has high mobility and has a characteristic that the difference in ionization potential with CGM to be combined is 0.5 (eV) or less, and preferably 0. It is 0.25 (eV) or less.

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

The resin used for the charge transport layer (CTL) is, for example, polystyrene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd. Resins, 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, poly-
Examples include polymer organic semiconductors such as N-vinylcarbazole.

The most preferable binder for these CTLs is a polycarbonate resin. Polycarbonate resin is most preferable in improving dispersibility of CTM and electrophotographic characteristics. The ratio of the binder resin to the charge transport material is preferably 10 to 200 parts by mass with respect to 100 parts by mass of the binder resin. The thickness of the charge transport layer is preferably 10-40 μm.

Surface Layer By providing the above-described siloxane resin layer of the present invention as the surface layer of the photoconductor, a photoconductor having the most preferable layer constitution of the present invention can be obtained.

Although the most preferable photoconductor layer structure of the present invention has been exemplified above, a photoconductor layer structure other than the above may be used in the present invention.

Next, the toner used in the present invention will be described. The toner is preferably a polymerized toner in which the particle size distribution of individual toner particles and the shape are relatively uniform. Here, the polymerized toner means a toner obtained by forming a resin of a binder for a toner and forming a toner shape by polymerizing a raw material monomer of the binder resin and subsequent chemical treatment. More specifically, it means a toner obtained through a polymerization reaction such as suspension polymerization and emulsion polymerization and, if necessary, a fusion process of particles that are carried out after the polymerization reaction.

The polymerized toner used in the image forming method of the present invention is preferably a toner having a specific shape. The polymerized toner that can be preferably used in the present invention will be described below.

In the digital image forming method for developing a dot image, it is preferable to use a toner having a small variation in shape factor and particle size distribution for development in order to enhance the sharpness of the image and obtain a good image. That is, a toner having a smaller variation can more accurately reproduce a fine dot image and is less likely to cause filming that causes image defects such as black spots.

As a result of the examination from the above viewpoints, by using a toner in which the variation coefficient of the shape factor of the toner is 16% or less and the variation coefficient of the number particle size distribution of the toner is 27% or less, It has been found that it is possible to form a high-quality image over a long period of time with excellent cleaning properties and fine line reproducibility.

Preferred polymerized toners applicable to the present invention are toner particles having a shape factor in the range of 1.2 to 1.6 of 65% by number or more, and a variation coefficient of the shape factor of 1.
To use a toner that is 6% or less. It has been found that even if such a polymerized toner is used, excellent cleaning performance is exhibited in the present invention.

Further, by using toner particles having no corners of 50 number% or more and controlling the number variation coefficient in the number particle size distribution to 27% or less, excellent cleaning property, fine line reproducibility and high quality are obtained. The image quality can be formed over a long period of time.

The shape factor of the toner of the present invention is represented by the following formula and represents the degree of roundness of toner particles.

Shape factor = ((maximum diameter / 2) ² × π) / projected area Here, the maximum diameter means that when a projected image of a toner particle on a plane is sandwiched by two parallel lines, the parallel line Refers to the width of the particles at which the interval is maximum. The projected area means the area of the projected image of the toner particles on the plane.

In the present invention, this shape factor is determined by taking a photograph of the toner particles magnified 2000 times with a scanning electron microscope, and then, based on this photograph, "SCANNING" is used.
It was measured by analyzing a photographic image using "IMAGE ANALYZER" (manufactured by JEOL Ltd.). At this time, the shape factor of the present invention was measured by the above calculation formula using 100 toner particles.

The preferable polymerized toner of the present invention is that the number of toner particles having the shape factor in the range of 1.2 to 1.6 is 65% by number or more, and more preferably 7
It is 0% by number or more.

When the number of toner particles having the shape factor in the range of 1.2 to 1.6 is 65% by number or more, the triboelectrification property in the developer carrying member becomes more uniform, and the excessively charged toner is obtained. Is not accumulated and the toner is more easily exchanged than on the surface of the developer transport member, so that problems such as development ghost are less likely to occur. Further, the toner particles are less likely to be crushed, the contamination of the charging member is reduced, and the charging property of the toner is stabilized.

The method of controlling the shape factor is not particularly limited. For example, a method of spraying toner particles in a hot air stream, a method of repeatedly applying mechanical energy by impact force in a gas phase in a gas phase, or a method of adding a toner to a solvent that does not dissolve toner to give a swirling flow, etc. To prepare a toner having a shape factor of 1.2 to 1.6, and add it to a normal toner so as to be within the range of the present invention. Also, controlling the overall shape at the stage of preparing a so-called polymerization toner,
There is a method in which a toner having a shape factor of 1.0 to 1.6 or 1.2 to 1.6 is similarly added to an ordinary toner to prepare the toner.

The variation coefficient of the shape factor of the polymerized toner preferably used in the present invention is calculated by the following formula.

Coefficient of variation = [S / K] × 100 (%) [In the formula, S represents the standard deviation of the shape factors of 100 toner particles, and K represents the average value of the shape factors. The variation coefficient of the shape factor is 16% or less, preferably 14% or less. When the variation coefficient of the shape factor is 16% or less, the voids of the transferred toner layer are reduced, the fixability is improved, and the offset is less likely to occur. In addition, the charge amount distribution becomes sharp and the image quality is improved.

In order to uniformly control the shape factor and the variation coefficient of the shape factor of the toner without extremely lot variation, while being formed in the step of polymerizing, fusing and controlling the shape of the resin particles (polymer particles). An appropriate process end time may be determined while monitoring the characteristics of certain toner particles (colored particles).

Monitoring means that a measuring device is installed in-line and the process conditions are controlled based on the measurement result. That is, in the case of a polymerization toner in which measurement of a shape or the like is incorporated inline, for example, a resin toner is formed by associating or fusing resin particles in an aqueous medium, the shape and the particle size are measured while performing sequential sampling in the steps such as fusing. Is measured, and the reaction is stopped when the desired shape is obtained.

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

The number particle size distribution and the number variation coefficient of the toner are measured by Coulter Counter TA-II or Coulter Multisizer (manufactured by Coulter Co.). In the present invention, a Coulter Multisizer was used, and an interface (manufactured by Nikkaki Co., Ltd.) for outputting the particle size distribution and a personal computer were connected and used.
The aperture used in the Coulter Multisizer was 100 μm, and the volume and number of toner particles of 2 μm or more were measured to calculate the particle size distribution and average particle size. 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 diameter in the number particle size distribution.

The number variation coefficient in the number particle size distribution of toner is calculated from the following formula. Number variation coefficient = [S / Dn] × 100 (%) [In the formula, S represents the standard deviation in the number particle size distribution, and D
n indicates a number average particle diameter (μm). The toner number variation coefficient is 27% or less, preferably 25% or less. When the number variation coefficient is 27% or less, the voids of the transferred toner layer are reduced, the fixing property is improved, and the offset hardly occurs. Further, the charge amount distribution becomes sharp, the transfer efficiency is improved, and the image quality is improved.

The method of controlling the number variation coefficient 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 reducing the number variation coefficient. As a method of classifying in this liquid, there is a method of controlling the number of revolutions and separately collecting and preparing toner particles according to the difference in sedimentation speed caused by the difference in toner particle diameter.

Particularly when the toner is produced by the suspension polymerization method, the classification operation is indispensable in order to keep the number variation coefficient in the number particle size distribution at 27% or less. In the suspension polymerization method,
Before the polymerization, it is necessary to disperse the polymerizable monomer into an oil droplet having a desired size as a toner in an aqueous medium. That is, the large oil droplets of the polymerizable monomer are repeatedly mechanically sheared by a homomixer or a homogenizer to reduce the oil droplets to the size of toner particles. In the method of different shearing, the number particle size distribution of the obtained oil droplets becomes wide, and therefore,
The toner obtained by polymerizing this also has a wide particle size distribution. For this reason, classification operation is essential.

The toner particles having no corners are toner particles that do not substantially have a projection where electric charge is concentrated or a projection that is easily worn by stress, that is, as shown in FIG. In addition, when the major axis of the toner particles T is L, a circle C having a radius (L / 10) is in contact with the peripheral line of the toner particles T at one point, and when the inside is rolled, the circle C When the toner does not substantially protrude outside the toner T, it is referred to as “cornerless toner particles”. The term “when substantially not protruding” means a case where there is one or less protrusions with protruding circles. Also, "long diameter of toner particles"
The term "means the width of a particle in which the distance between the parallel lines is maximum when the projected image of the toner particle on the plane is sandwiched by two parallel lines. Note that FIGS. 1B and 1C show projected images of toner particles having corners, respectively.

The toner having no corners was measured as follows. First, an enlarged photograph of toner particles is taken with a scanning electron microscope and further enlarged to obtain a photographic image at 15,000 times. Then, the presence or absence of the above-mentioned corner is measured for this photographic image. This measurement was performed on 100 toner particles.

In the toner of the present invention, the proportion of toner particles having no corners is 50% by number or more, preferably 70% by number or more. When the ratio of the toner particles having no corners is 50% by number or more, the generation of fine particles is less likely to occur due to the stress with the developer transport member and the like,
It is possible to prevent the presence of toner with excessive adhesion to the surface of the developer transport member, suppress contamination of the developer transport member, and make the charge amount sharp. Further, the toner particles that are easily worn or broken and the toner particles having a portion where the electric charge is concentrated are reduced, the charge amount distribution becomes sharp, the chargeability becomes stable, and good image quality can be formed for a long time.

The method for obtaining toner without corners is not particularly limited. For example, as described above as a method of controlling the shape factor, a method of spraying toner particles in a hot air flow, a method of repeatedly applying mechanical energy due to impact force in a gas phase, or a method of dissolving toner It can be obtained by adding it to a solvent that does not contain it and imparting a swirling flow.

Further, in the polymerized toner formed by associating or fusing resin particles, the surface of the fused particles has many irregularities at the step of stopping the fusion, and the surface is not smooth, but in the shape controlling step. The toner having no corners can be obtained by appropriately adjusting the conditions such as the temperature, the rotation speed of the stirring blade, and the stirring time. These conditions vary depending on the physical properties of the resin particles, but for example, by setting the glass transition temperature of the resin particles or higher to a higher rotation speed, the surface becomes smooth and toner without corners can be formed.

The particle diameter of the toner of the present invention is preferably 3 to 8 μm in number average particle diameter. When the toner particles are formed by a polymerization method, this particle size can be controlled by the concentration of the aggregating agent, the amount of the organic solvent added, the fusing time, and the composition of the polymer itself.

By having the number average particle diameter of 3 to 8 μm, it is possible to reduce the presence of excessively adherent toner or toner having low adherence to the developer conveying member in the fixing step, and to improve the developability. It can be stabilized for a long period of time, the transfer efficiency is improved, the halftone image quality is improved, and the image quality of fine lines, dots, etc. is improved.

As the polymerized toner preferably used in the present invention, when the particle diameter of the toner particles is D (μm), the natural logarithm lnD is plotted on the horizontal axis, and the horizontal axis is divided into a plurality of classes at intervals of 0.23. in histogram showing the particle size distribution of number criteria, the relative frequency of the toner particles contained in the modal class (m _1), the relative frequency of the toner particles contained in the following frequent the rank of the modal class (m ₂ ) And (M) is 7
The toner is preferably 0% 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 becomes narrow, so that the toner is used in the image forming process. By using it, the occurrence of selective development can be surely suppressed.

In the present invention, the histogram showing the number-based particle size distribution has a natural logarithm lnD (D: particle size of individual toner particles) at a plurality of grades (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:
1.84-2.07: 2.07-2.30: 2.30-
2.53: 2.53 to 2.76 ...), which is a histogram showing a number-based particle size distribution, and the histogram shows 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 is created by the particle size distribution analysis program in the computer.

[Measurement Conditions] (1) Aperture: 100 μm (2) Sample Preparation Method: Electrolyte Solution [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 stirred, and 10 to 20 mg of a measurement sample is added thereto. This system is prepared by subjecting it to an ultrasonic disperser for 1 minute.

Among the methods for controlling the shape factor, the polymerized toner is preferable because it is simple as a manufacturing method, and the surface uniformity is excellent as compared with the pulverized toner.

The toner of the present invention is obtained by suspension polymerization or emulsion polymerization of a monomer in a liquid containing an emulsion of necessary additives.
It can be manufactured by a method in which finely divided polymer particles are produced, and thereafter, an organic solvent, an aggregating agent and the like are added and associated. At the time of association, a method of preparing by mixing with a dispersion liquid such as a release agent or a colorant necessary for the constitution of the toner to allow association, or dispersing a toner constituent component such as a release agent or a colorant in a monomer Then, a method of emulsion polymerization may be used. Here, the association means that a plurality of resin particles and colorant particles are fused.

The aqueous medium referred to in the present invention means a medium containing at least 50% by mass of water.

That is, various constituent materials such as a coloring agent and, if necessary, a releasing agent, a charge control agent, and a polymerization initiator are added to the polymerizable monomer, and a homogenizer, a sand mill, a sand grinder, and an ultrasonic dispersion are added. Various constituent materials are dissolved or dispersed in the polymerizable monomer by a machine or the like. The polymerizable monomer in which these various constituent materials are dissolved or dispersed is dispersed in an oil droplet having a desired size as a toner in a water-based medium containing a dispersion stabilizer by using a homomixer or a homogenizer. Then, the stirring mechanism is transferred to a reaction device which is a stirring blade described later and heated to allow the polymerization reaction to proceed. After the completion of the reaction, the dispersion stabilizer is removed, filtered, washed, and dried to prepare a toner.

Further, as a method for producing the toner of the present invention, a method of preparing resin particles by associating or fusing them in an aqueous medium can be mentioned. This method is not particularly limited, but for example, JP-A-5-26
The methods shown in JP-A-5252, JP-A-6-329947 and JP-A-9-15904 can be mentioned. That is, a method of associating a plurality of resin particles and dispersed particles of a constituent material such as a colorant, or a plurality of fine particles composed of a resin and a colorant, in particular, after dispersing these in water with an emulsifier, the critical aggregation concentration At the same time as salting out by adding the aggregating agent above, while gradually growing the particle size while forming fused particles by heat fusion above the glass transition temperature of the polymer itself formed, the target particle size and After that, a large amount of water is added to stop the particle size growth, and the surface of the particles is smoothed while heating and stirring to control the shape, and the particles are heated and dried in a fluid state in a water-containing state. Can be formed. Here, an organic solvent that is infinitely soluble in water may be added simultaneously with the coagulant.

Those usable as the polymerizable monomer constituting the resin include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-chlorostyrene and 3,4- Dichlorostyrene,
p-phenylstyrene, p-ethylstyrene, 2,4-
Dimethyl styrene, p-tert-butyl styrene, p
-N-hexyl styrene, pn-octyl styrene,
pn-nonylstyrene, pn-decylstyrene, p
Styrene or styrene derivative such as -n-dodecyl styrene, methyl methacrylate, ethyl methacrylate,
N-butyl methacrylate, isopropyl methacrylate,
Methacrylate ester derivatives such as isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, dimethylaminoethyl methacrylate. , Methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate,
Acrylic ester derivatives such as n-octyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate and phenyl acrylate, olefins such as ethylene, propylene and isobutylene, vinyl chloride, vinylidene chloride, vinyl bromide , Vinyl fluoride, vinylidene fluoride, and other halogen-based vinyls, vinyl propionate, vinyl acetate, vinyl benzoate, and other vinyl esters, vinyl methyl ether, vinyl ethyl ether, and other vinyl ethers, vinyl methyl ketone, vinyl ethyl ketone , Vinyl ketones such as vinyl hexyl ketone, N-vinyl compounds such as N-vinyl carbazole, N-vinyl indole and N-vinyl pyrrolidone, vinyl compounds such as vinyl naphthalene and vinyl pyridine, acrylonitrile, Acrylonitrile, there are acrylic acid or methacrylic acid derivatives such as acrylamide. These vinyl monomers can be used alone or in combination.

Further, it is more preferable to use a combination of those having an ionic dissociative group as the polymerizable monomer constituting the resin. For example, those having a substituent such as a carboxyl group, a sulfonic acid group, and a phosphoric acid group as a constituent group of the monomer, and specifically, acrylic acid, methacrylic acid,
Maleic acid, itaconic acid, cinnamic acid, fumaric acid, maleic acid monoalkyl ester, itaconic acid monoalkyl ester, styrenesulfonic acid, allylsulfosuccinic acid, 2-acrylamido-2-methylpropanesulfonic acid, acid phosphooxyethyl Methacrylate,
3-chloro-2-acid phosphooxypropyl methacrylate and the like can be mentioned.

Further, divinylbenzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate,
It is also possible to use a polyfunctional vinyl such as neopentyl glycol diacrylate to form a resin having a crosslinked structure.

These polymerizable monomers can be polymerized using a radical polymerization initiator. In this case, an oil-soluble polymerization initiator can be used in the suspension polymerization method. As this oil-soluble polymerization initiator, 2,2'-azobis- (2,4
-Dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvalero Azo-based or diazo-based polymerization initiators such as nitrile and azobisisobutyronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, t-butyl hydroperoxide, di-t-butyl peroxide. , Dicumyl peroxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, 2,2-bis-
Examples include peroxide polymerization initiators such as (4,4-t-butylperoxycyclohexyl) propane and tris- (t-butylperoxy) triazine, and polymer initiators having a peroxide in the side chain. .

When the emulsion polymerization method is used, a water-soluble radical polymerization initiator can be used. Examples of the water-soluble polymerization initiator include persulfates such as potassium persulfate and ammonium persulfate, azobisaminodipropane acetic acid salts, azobiscyanovaleric acid and its salts, and hydrogen peroxide.

Examples of the dispersion stabilizer include tricalcium phosphate, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate. , Barium sulfate,
Examples thereof include bentonite, silica and alumina. Furthermore, polyvinyl alcohol, gelatin, methyl cellulose, sodium dodecylbenzene sulfonate, ethylene oxide adduct, higher alcohol sodium sulfate, and the like which are commonly used as surfactants can be used as the dispersion stabilizer.

The resin excellent in the present invention preferably has a glass transition point of 20 to 90 ° C. and a softening point of 8
It is preferably 0 to 220 ° C. The glass transition point is measured by a differential calorimetric method, and the softening point can be measured by a Koka type flow tester. Furthermore, these resins have a number average molecular weight (Mn) of 10 as measured by gel permeation chromatography.
00-100,000, 200 in weight average molecular weight (Mw)
It is preferably 0 to 1,000,000. Furthermore, as the molecular weight distribution, Mw / Mn is 1.5 to 100, and particularly 1.8.
The thing of -70 is preferable.

The aggregating agent used is not particularly limited, but one selected from metal salts is preferably used. Specifically, monovalent metals such as salts of alkali metals such as sodium, potassium and lithium, divalent metals such as alkaline earth metal salts such as calcium and magnesium, divalent metals such as manganese and copper. Salt of
Examples thereof include salts of trivalent metals such as iron and aluminum, and specific salts include sodium chloride, potassium chloride, lithium chloride, calcium chloride, zinc chloride, copper sulfate, magnesium sulfate, manganese sulfate and the like. You can
These may be used in combination.

It is preferable to add these coagulants at a critical coagulation concentration or higher. This critical coagulation concentration is an index relating to the stability of the aqueous dispersion, and indicates the concentration at which coagulation occurs when a coagulant is added. This critical aggregation concentration is
It greatly changes depending on the emulsified component and the dispersant itself. For example, Seizo Okamura et al., "Polymer Chemistry 1"
7, 601 (1960) edited by The Society of Polymer Science, Ltd., etc., and a detailed critical aggregation concentration can be obtained. As another method, a desired salt is added to the target particle dispersion at different concentrations, the ζ (zeta) potential of the dispersion is measured, and the salt concentration at which this value changes is determined as the critical aggregation concentration. You can also ask.

The amount of the aggregating agent added may be a critical coagulation concentration or more, but is preferably 1.2 times or more the critical coagulation concentration.
It is more preferable to add 1.5 times or more.

The infinitely soluble solvent means a solvent infinitely soluble in water, and a solvent which does not dissolve the resin formed in the present invention is selected as this solvent.
Specifically, methanol, ethanol, propanol,
Examples thereof include alcohols such as isopropanol, t-butanol, methoxyethanol, butoxyethanol, nitriles such as acetonitrile, and ethers such as dioxane. Particularly, ethanol, propanol and isopropanol are preferable.

The amount of the solvent that dissolves infinitely is 1 to 100% by volume with respect to the polymer-containing dispersion liquid to which the aggregating agent is added.
Is preferred.

In order to make the shape uniform, it is preferable to prepare colored particles, and after filtering, slurry in which 10% by mass or more of water is present with respect to the particles is fluidized and dried. Those having a polar group in the polymer are preferred. It is considered that the reason for this is that since the existing water exerts an effect of swelling the existing water to some extent with respect to the polymer having the polar group, the homogenization of the shape is particularly likely to occur.

The toner of the present invention contains at least a resin and a colorant, but may contain a releasing agent which is a fixing property improving agent, a charge control agent and the like, if necessary. Further, an external additive composed of inorganic fine particles, organic fine particles or the like may be added to the toner particles containing the resin and the colorant as main components.

The colorant used in the toner of the present invention may be any carbon black, magnetic substance, dye, pigment or the like. Examples of carbon black include channel black, furnace black, acetylene black,
Thermal black, lamp black, etc. are used. Ferromagnetic metals such as iron, nickel, and cobalt as magnetic materials,
Alloys containing these metals, compounds of ferromagnetic metals such as ferrite and magnetite, alloys containing no ferromagnetic metals but exhibiting ferromagnetism by heat treatment, such as manganese-copper-
Aluminum, manganese-copper-tin, and other types of alloys called Heusler alloys, chromium dioxide, and the like can be used.

As the dye, C.I. I. Solvent Red 1, 49, 52, 58, 63, 111, 1
22, C.I. I. Solvent Yellow 19, 44, 7
7, ibid 79, ibid 81, ibid 82, ibid 93, ibid 98, ibid 10
3, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 60, 70, 93, 9
5 and the like can be used, and a mixture thereof can also be used. As the pigment, C.I. I. Pigment Red 5,
48: 1, 53: 1, 57: 1, 122, 1
39, 144, 149, 166, 177, 1
78, ibid. 222, C.I. I. Pigment Orange 31, the same 43, C.I. I. Pigment Yellow 14, Same 17 and Same 9
3, 94, 138, C.I. I. Pigment Green 7, C.I. I. Pigment Blue 15: 3, 60 and the like, and a mixture thereof can also be used. The number average primary particle size varies depending on the type, but is generally about 10
About 200 nm is preferable.

The colorant may be added by adding polymer particles prepared by an emulsion polymerization method at the stage of aggregating by adding an aggregating agent to color the polymer, or by polymerizing a monomer. It is possible to use a method in which a coloring agent is added and polymerized to obtain colored particles. When the colorant is added at the stage of preparing the polymer, it is preferable that the surface is treated with a coupling agent or the like so as not to hinder radical polymerizability.

Further, low molecular weight polypropylene (number average molecular weight = 1500 to 9000), low molecular weight polyethylene or the like as a fixability improving agent may be added.

Similarly, the charge control agents are various known ones,
Moreover, the thing which can be disperse | distributed in water can be used. Specifically, nigrosine dyes, metal salts of naphthenic acid or higher fatty acids, alkoxylated amines,
Examples thereof include secondary ammonium salt compounds, azo-based metal complexes, salicylic acid metal salts or metal complexes thereof.

The particles of these charge control agents and fixability improvers have a number average primary particle diameter of 10 to 50 in a dispersed state.
It is preferably about 0 nm.

A suspension polymerization method toner in which a toner component such as a colorant or the like is dispersed or dissolved in a so-called polymerizable monomer is suspended in an aqueous medium and then polymerized to obtain a toner is subjected to a polymerization reaction. The shape of the toner particles can be controlled by controlling the flow of the medium in the reaction vessel. That is, when a large number of toner particles having a shape factor of 1.2 or more are formed, the flow of the medium in the reaction vessel is made turbulent, and the polymerization proceeds to exist in the aqueous medium in a suspended state. When the oil droplets gradually become polymerized and become soft particles, the particles collide with each other to promote coalescence of the particles, and particles with an irregular shape are obtained. . When spherical toner particles having a shape factor of less than 1.2 are formed, spherical particles can be obtained by avoiding collision of particles by making the flow of the medium in the reaction vessel a laminar flow. By this method, the distribution of toner shape can be controlled within the range of the present invention.

The reaction device for polymerized toner preferably used in the present invention will be described below. First, a reaction apparatus preferably used for producing a polymerized toner will be described.
2 and 3 are a perspective view and a cross-sectional view showing an example of a polymerized toner reaction device, respectively. In the reactor shown in FIGS. 2 and 3, a rotating shaft 3 is vertically installed at the center of a vertical cylindrical stirring tank 2 having a jacket 1 for heat exchange mounted on the outer periphery thereof, and stirring is performed on the rotating shaft 3. A lower stirring blade 40 arranged near the bottom surface of the tank 2 and a stirring blade 50 arranged further above are provided. The upper stirring blade 50 is
The stirring blades 40 located in the lower stage are arranged with a crossing angle α that precedes them in the rotational direction. In the case of producing the toner of the present invention, the crossing angle α is preferably less than 90 degrees (°). The lower limit of the intersection angle α is not particularly limited, but is preferably about 5 ° or more, and more preferably 10 ° or more. When three-stage stirring blades are provided, the intersecting angle α between adjacent stirring blades is preferably less than 90 degrees.

With such a configuration, the medium is first stirred by the stirring blade 50 arranged in the upper stage, and a downward flow is formed. Then, the stirring blade 40 arranged in the lower stage accelerates the flow formed by the stirring blade 50 in the upper stage further downward, and the stirring blade 50 itself also forms a downward flow, so that the flow as a whole is reduced. It is estimated to accelerate and proceed. As a result, a basin having a large shear stress formed as a turbulent flow is formed, and it is presumed that the shape of the obtained toner particles can be controlled.

2 and 3, the arrow indicates the direction of rotation, 7 is the upper material charging port, 8 is the lower material charging port, and 9 is.
Is a turbulent flow forming member for making stirring effective.

Here, the shape of the stirring blade is not particularly limited, but it has a rectangular plate shape, a blade with a notch, and a central portion with one or more holes, so-called slits. Things etc. can be used. Specific examples of these are shown in FIG. Stirring blade 5 shown in FIG.
a has no central hole, the stirring blade 5b shown in FIG. 6B has a large central hole 6b in the center, and the stirring blade 5c shown in FIG. 6C has a horizontally long central hole 6c (slit). ), The stirring blade 5d shown in FIG.
There is a (slit). Further, in the case of providing a three-stage stirring blade, even if the middle hole portion formed in the upper stirring blade and the middle hole portion formed in the lower stirring blade are different, they may be the same. It may be.

The gap between the upper-stage and lower-stage stirring blades having the above structure is not particularly limited, but it is preferable that there is a gap at least between the stirring blades. The reason for this is not clear, but it is considered that the stirring efficiency is improved because the flow of the medium is formed through the gap. However, the gap has a width of 0.5 to 50%, preferably a width of 1 to 30% with respect to the liquid surface height in a stationary state.

Further, the size of the stirring blades is not particularly limited, but the total height of all stirring blades is 50% to 100%, preferably 60% to 50% of the liquid surface height in a stationary state. 95
%.

On the other hand, in the case of a polymerized toner in which resin particles are associated or fused in an aqueous medium, the flow and temperature distribution of the medium in the reaction vessel at the fusion stage are controlled to further improve the shape after fusion. By controlling the heating temperature, stirring rotation number, and time in the control step, the shape distribution and shape of the entire toner can be arbitrarily changed.

That is, in the case of the polymerization toner in which the resin particles are associated or fused, the flow in the reaction device is a laminar flow,
By using a stirring blade and a stirring tank that can make the internal temperature distribution uniform, by controlling the temperature, rotation speed, and time in the fusion process and shape control process, the desired shape factor and uniform A toner having a shape distribution can be formed. The reason for this is that when fusion is performed in a laminar flow-forming place, strong stress is not applied to particles (association or agglomerated particles) in which aggregation and fusion are progressing, and in a laminar flow in which the flow is accelerated, It is presumed that, as a result of the uniform temperature distribution in the stirring tank, the shape distribution of the fused particles becomes uniform. Furthermore, heating in the subsequent shape control process,
By stirring, the fused particles gradually become spherical and the shape of the toner particles can be arbitrarily controlled.

As the stirring tank used in the production of the polymerization toner in which the resin particles are associated or fused, the same one as in the suspension polymerization method can be used. In this case, it is necessary not to provide an obstacle such as a baffle plate that forms a turbulent flow in the stirring tank.

The shape of this stirring blade is not particularly limited as long as it forms a laminar flow and does not form a turbulent flow. However, a continuous surface such as a rectangular plate shown in FIG. 4C is used. What is formed is preferable, and may have a curved surface.

Further, in the toner used in the present invention, it is possible to more effectively exhibit the effect by adding fine particles such as inorganic fine particles and organic fine particles as an external additive.
The reason for this is presumed to be that the embedding and detachment of the external additive can be effectively suppressed, and the effect is remarkable.

As the inorganic fine particles, it is preferable to use inorganic oxide particles such as silica, titania and alumina, and these inorganic fine particles are subjected to a hydrophobic treatment with a silane coupling agent or a titanium coupling agent. preferable. The degree of hydrophobic treatment is not particularly limited, but methanol wettability of 40 to 95 is preferable. Methanol wettability is an evaluation of wettability with respect to methanol. In this method, 50 ml of distilled water placed in a beaker with an internal volume of 200 ml was charged with inorganic fine particles to be measured in an amount of 0.
Weigh 2 g and add. Methanol is dripped slowly from a buret whose tip is dipped in the liquid, with slow stirring until the whole inorganic fine particles become wet. When the amount of methanol required to completely wet the inorganic fine particles is a (ml), the degree of hydrophobicity is calculated by the following formula.

Hydrophobicity = (a / (a + 50)) × 100 The addition amount of this external additive is 0.1 to 5% in the toner.
It is 0% by mass, preferably 0.5 to 4.0% by mass. Further, various external additives may be used in combination.

A fatty acid metal salt may be added as an external additive to the toner used in the present invention. Fatty acids and metal salts thereof include undecyl acid, lauric acid, tridecyl acid, dodecyl acid, myristic acid, palmitic acid, pentadecyl acid, stearic acid, heptadecyl acid, arachidic acid, montanic acid, oleic acid, linoleic acid, arachidonic acid, etc. And long-chain fatty acids thereof, and examples of the metal salt thereof include salts with metals such as zinc, iron, magnesium, aluminum, calcium, sodium and lithium. In the present invention, zinc stearate is particularly preferable. << Developer >> The toner used in the present invention may be a one-component developer or a two-component developer, but is preferably a two-component developer.

In the case of using as a one-component developer, there is a method of using the toner as it is as a non-magnetic one-component developer, but usually, the magnetic particles are made to contain magnetic particles of about 0.1 to 5 μm in the toner particles. Used as a developer. As a method of containing it, it is common to incorporate it in the non-spherical particles in the same manner as the colorant.

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

The volume average particle diameter of the carrier is typically measured by a laser diffraction type particle size distribution measuring apparatus "HELOS" equipped with a wet disperser (SYMPATIC (SYMP).
(Made by ATEC)).

The carrier is preferably a magnetic particle further coated with a resin, or a so-called resin dispersion type carrier in which magnetic particles are dispersed in a resin. The resin composition for coating is not particularly limited, but 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-dispersed carrier is not particularly limited, and known ones can be used, and for example, styrene acrylic resin, polyester resin, fluorine resin, phenol resin, etc. can be used. it can.

The two-component developer is prepared by mixing the toner and the carrier. The toner is mixed in a toner concentration of 2 to 10% by mass based on the developer.

The developing method according to the present invention is not particularly limited. Even in the contact development method in which development is performed in a state where the surface of the photoconductor and the developer layer are in contact with each other in the development area, the photoconductor and the developer layer are kept in the non-contact state in the development area, and an alternating electric field, etc. A non-contact developing method in which toner is caused to fly in the gap between the surface of the photoconductor and the developer layer by the action to develop the toner may be used.

FIG. 5 is a sectional view of an image forming apparatus as an example of the image forming method of the present invention. In FIG. 5, reference numeral 50P denotes a photosensitive drum (photosensitive member) which is an image bearing member, and is a photosensitive member in which an organic photosensitive layer is coated on the drum, and the surface layer of the present invention is coated thereon, which is grounded. It is driven and rotated clockwise. 5
Reference numeral 2 denotes a scorotron charger (charging means) for uniformly charging the peripheral surface of the photosensitive drum 50P by corona discharge. Prior to the charging by the charger 52, in order to eliminate the history of the photosensitive member in the pre-image formation, the pre-charging pre-exposure unit 51 using a light emitting diode or the like may be used to remove the charge on the peripheral surface of the photosensitive member.

After uniformly charging the photosensitive member, the image exposing device (image exposing means) 53 performs image exposure based on the image signal. The image exposure device 53 in this figure uses a laser diode (not shown) as an exposure light source. Rotating polygon mirror 53
1, the light whose optical path is bent by the reflection mirror 532 through the f.theta. Lens, etc., scans the photosensitive drum to form an electrostatic latent image.

The reversal development of the present invention means that the surface of the photoconductor is uniformly charged by the charger 52, and the image-exposed region, that is, the exposed portion potential (exposed portion region) of the photosensitive member is developed. It is an image forming method for visualizing. On the other hand, the unexposed portion potential is not developed by the developing bias potential applied to the developing sleeve 541.

The electrostatic latent image is then developed by a developing device (developing means).
It is developed at 54. A developing device 54 containing a developer composed of toner and carrier is provided on the peripheral edge of the photoconductor drum 50P, and development is performed by a developing sleeve 541 that contains a magnet, holds the developer, and rotates. The inside of the developing device 54 is composed of developer agitating / conveying members 544 and 543, a conveying amount regulating member 542, and the like, and the developer is agitated and conveyed to be supplied to the developing sleeve. Controlled by member 542. The amount of the developer conveyed varies depending on the linear velocity of the electrophotographic photosensitive member and the specific gravity of the developer, but is generally 20 to 200 m.
It is in the range of g / cm ² .

The developer is, for example, a carrier having ferrite as a core and coated with an insulating resin around the core, a coloring agent such as carbon black containing the above-mentioned styrene acrylic resin as a main material, a charge control agent, and the low molecular weight of the present invention. The toner is formed by externally adding silica, titanium oxide, or the like to colored particles made of polyolefin. The developer is transported to the developing area with its layer thickness regulated by the transport amount regulating member, and development is performed. At this time, normally, the photosensitive drum 50
Development is performed by applying a DC bias voltage between P and the developing sleeve 541, and an AC bias voltage as necessary. Also,
The developer is developed in a state of being in contact or non-contact with the photoconductor. The potential of the photoconductor is measured by providing a potential sensor 547 above the developing position as shown in FIG.

After the image formation, the recording paper P is fed to the transfer area by the rotation operation of the paper feed roller 57 when the transfer timing is adjusted.

In the transfer area, the toner on the photoconductor is transferred onto the recording paper P fed by the transfer electrode (transfer means) 58 which gives an electric charge having a polarity opposite to that of the toner.

Next, the recording paper P is separated into electrodes 5 (separation means).
9, the charge is removed, the toner is separated from the peripheral surface of the photoconductor drum 50P and conveyed to a fixing device (fixing means) 60. The heat roller 601 and the pressure roller 602 heat and press the toner to fuse the toner, and then the paper discharge roller 61. It is discharged to the outside of the device via. The transfer electrode 58 and the separation electrode 59 are withdrawn from the peripheral surface of the photosensitive drum 50P after the recording paper P has passed and are ready for the next toner image formation.

On the other hand, after the recording paper P is separated, the photosensitive drum 50P removes and cleans the residual toner by pressing the blade 621 of the cleaning device (cleaning means) 62 to remove and clean the residual toner, and the pre-charging exposure unit 51 again removes electricity and charges the charger. Upon receiving the charge from 52, the next image forming process starts.

Reference numeral 70 denotes a detachable process cartridge in which a photoconductor, a charger, a transfer device, a separator and a cleaning device are integrated.

The image forming method and the image forming apparatus of the present invention are applicable to general electrophotographic apparatuses such as electrophotographic copying machines, laser printers, LED printers and liquid crystal shutter type printers. It can also be widely applied to devices such as light printing, plate making, and facsimile.

[0208]

The present invention will be described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto. In addition, "part" in a sentence represents a "mass part."

The intermediate layer dispersions of Examples and Comparative Examples were prepared as follows. Preparation of intermediate layer dispersion liquid 1 Polyamide resin CM8000 (manufactured by Toray) 1 part Titanium oxide SMT500SAS (manufactured by Teika; surface treatment is silica treatment, alumina treatment, and methylhydrogenpolysiloxane treatment) 3 parts Methanol 10 parts sand mill The dispersion time was 10 hours with a disperser and the dispersion was carried out in a batch manner to prepare an intermediate layer dispersion liquid 1.

Preparation of Intermediate Layer Dispersions 2 to 7 Intermediate Layer Dispersions 2 to 2 were prepared in the same manner as Intermediate Layer Dispersion 1 except that titanium oxide, its surface treatment, particle size, and solvent were changed as shown in Table 1. 7 was produced.

Preparation of Intermediate Layer Dispersion Liquid 8 (Comparative Example) 1 part of polyamide resin CM8000 (manufactured by Toray Industries, Inc.) was added to and dissolved in a mixed solvent of 7 parts of methanol and 3 parts of 1-propanol to obtain intermediate layer dispersion liquid 8. It was made.

Preparation of Intermediate Layer Dispersion Liquid 9 (Comparative Example) Instead of titanium oxide particles, silica particles (Aerosil R8) were used.
05, Tegusa Co .: not N-type semiconducting particles) was prepared in the same manner as Intermediate Layer Dispersion Liquid 1 to prepare Intermediate Layer Dispersion Liquid 9.

[0213]

[Table 1]

In Table 1, those listed in the primary treatment column are substances deposited on the surface of titanium oxide particles after the primary treatment,
The items described in the secondary treatment column indicate the substances used in the secondary treatment.

Preparation of Photoreceptors 1 to 10 The following intermediate layer coating solution 1 was prepared, coated on a cylindrical aluminum substrate whose surface roughness was changed as shown in Table 2 by a dip coating method, and dried. The film thickness was also changed as shown in Table 2 to form the intermediate layers 1 to 10. In the present invention, the drying condition is low temperature drying and is controlled slowly so that Benard cells are easily generated stably. Drying conditions are 60 ℃, 10 minutes, 4
It was dried at 0 ° C. for 30 minutes.

The volume resistance of each intermediate layer after drying was in the range of 1 × 10 ^{10 to} 3 × 10 ¹¹ Ω · cm under the above measurement conditions. <Intermediate layer (UCL) coating liquid 1> The intermediate layer dispersion liquid 1 was diluted 2-fold with the same mixed solvent, and allowed to stand overnight and then filtered (filter; Rigimesh filter manufactured by Nippon Pall Ltd. nominal filtration accuracy: 5 μm, pressure). 5 × 10 ⁴ Pa).

The following coating solutions were mixed and dispersed using a sand mill to prepare a charge generation layer coating solution. This coating solution is applied by a dip coating method to form a dry film thickness of 0.3 on each of the intermediate layers.
The charge generation layers 1 to 10 having a thickness of μm were formed.

<Charge Generating Layer (CGL) Coating Solution> Y-type oxytitanyl phthalocyanine (Cu-Kα characteristic X-rays has a maximum peak angle of 2θ of 27.3 at 27.3) 20 g Polyvinyl butyral (# 6000-C, electric Chemical Industry Co., Ltd.) 10 g t-butyl acetate 700 g 4-methoxy-4-methyl-2-pentanone 300 g The following coating solutions were mixed and dissolved to prepare a charge transport layer coating solution. This coating solution was applied onto the charge generating layers 1 to 10 by a dip coating method to form a charge transporting layer having a dry film thickness of 24 μm to prepare photoconductors 1 to 10.

<Charge Transport Layer (CTL) Coating Liquid> Charge Transport Agent (4- (2,2-diphenylvinyl) phenyl-di-p-trilylamine) 75 g Polycarbonate Resin (Upilon Z300: Mitsubishi Gas Chemical Co., Inc.) 100 g Chloride Methylene 750 g Preparation of Photoreceptors 11 to 18 In the preparation of the photoreceptor 4 described above, the intermediate layer dispersion 1 of the intermediate layer coating solution 1 was changed to the intermediate layer dispersions 2 to 9 to prepare the intermediate layer coating solutions 2 to 9. Except that the intermediate layers 2 to 9 were formed by using the intermediate layer coating liquids 2 to 9, the photosensitive member 4 (base surface roughness Rz:
1.0 μm) and the photoconductor 11
~ 18 were produced. The drying conditions are the same as the manufacturing conditions of the photoconductor 1.

The volume resistance of these intermediate layers 2 to 9 was in the range of 0.5 × 10 ^{10 to} 6 × 10 ¹⁰ Ω · cm under the above measurement conditions.

The contents of each of the above intermediate layers are shown in Table 2 including the evaluation of occurrence of Benard cells.

Evaluation 1 (Evaluation of Intermediate Layer) Further, the surface of the intermediate layer was observed with a scanning electron microscope at a magnification of 200, and a concave portion having a shape as shown in FIG. It was confirmed that they were formed on the front, back, left and right (Benard cell structure), and the following judgment was made. 6A shows a hexagonal concave portion, and b shows a spot-shaped concave portion.

⊚: Polygonal recesses with the longest length of 20 to 200 μm are formed in 50% or more of the intermediate surface layer. ○: Polygonal recesses with the longest length of 20 to 200 μm are 10 to 10 of the intermediate surface layer. 49% generation ×: Polygonal recesses with a maximum length of 20 to 200 μm were less than 10% of the intermediate surface layer XX: Polygonal recesses with a maximum length of 20 to 200 μm were generated on the intermediate surface layer at all The evaluation results are shown in Table 2.

[0224]

[Table 2]

Preparation of Toners 1-1 to 1-5 (Example of Emulsion Polymerization Association Method) 0.90 kg of sodium n-dodecyl sulfate and pure water 10.
Add 0 L and dissolve with stirring. To this solution, legal 330
After gradually adding 1.20 kg of R (carbon black manufactured by Cabot Corporation) and stirring well for 1 hour, the mixture was continuously dispersed for 20 hours using a sand grinder (medium type disperser). This is designated as "colorant dispersion liquid 1". Further, a solution composed of 0.055 kg of sodium dodecylbenzenesulfonate and 4.0 L of ion-exchanged water is referred to as "anionic surfactant solution A".

0.014 kg of nonylphenol polyethylene oxide adduct of 0.014 kg and ion-exchanged water of 4.0 L
The solution consisting of is referred to as "Nonionic surfactant solution B".
223.8 g of potassium persulfate, 12.0 L of ion-exchanged water
The solution dissolved in was designated as "initiator solution C".

In a 100 L GL (glass lining) reaction kettle equipped with a temperature sensor, a cooling pipe, and a nitrogen introducing device, W
AX emulsion (polypropylene emulsion having a number average molecular weight of 3000: number average primary particle size = 120 nm / solid content concentration = 29.9%) 3.41 kg and "anionic surfactant solution A" and the total amount and "nonionic surfactant solution B" Add the whole amount and start stirring. The structure of the stirring blade is shown in Fig. 4.
The configuration of (c) is adopted. Next, ion-exchanged water 44.0L
Add.

When heating was started and the liquid temperature reached 75 ° C., the entire amount of “initiator solution C” was added dropwise. Then, while controlling the liquid temperature to 75 ° C ± 1 ° C, styrene 1
2.1 kg, n-butyl acrylate 2.88 kg, methacrylic acid 1.04 kg and t-dodecyl mercaptan 54
8 g and is added dropwise. After the dropping was completed, the liquid temperature was raised to 80 ° C. ± 1 ° C., and the mixture was heated and stirred for 6 hours. Then, the liquid temperature is cooled to 40 ° C. or lower, stirring is stopped, and the mixture is filtered with a pole filter to obtain “latex-A”.

The resin particles in Latex-A had a glass transition temperature of 57 ° C., a softening point of 121 ° C., a molecular weight distribution of weight average molecular weight = 127,000, and a mass average particle diameter of 12.
It was 0 nm.

A solution prepared by dissolving 0.055 kg of sodium dodecylbenzenesulfonate in 4.0 L of ion-exchanged pure water is referred to as "anionic surfactant solution D". Also,
A solution in which 0.014 kg of a 10-mol addition product of nonylphenol polyethylene oxide is dissolved in 4.0 L of ion-exchanged water is referred to as “nonionic surfactant solution E”.

Potassium persulfate (manufactured by Kanto Chemical Co., Inc.) 200.
A solution prepared by dissolving 7 g in 12.0 L of ion-exchanged water is referred to as "initiator solution F".

A 100 L GL reactor equipped with a temperature sensor, a cooling pipe, a nitrogen introducing device, and a comb-shaped baffle (the stirring blade is configured as shown in FIG. 4 (c)) is charged with WAX emulsion (polypropylene emulsion having a number average molecular weight of 3000: number average). Primary particle size = 120 nm / solid content concentration 29.9%) 3.4
1 kg, the total amount of "anionic surfactant solution D" and the total amount of "nonionic surfactant solution E" are added, and stirring is started.
Next, 44.0 L of ion-exchanged water is added. When heating is started and the liquid temperature reaches 70 ° C., “initiator solution F” is added. Next, 11.0 kg of styrene, 4.00 kg of n-butyl acrylate and 1.04 of methacrylic acid.
A solution in which kg and 9.02 g of t-dodecyl mercaptan were mixed in advance was added dropwise. After the dropping is completed, the liquid temperature is set to 7
The temperature was controlled to 2 ° C ± 2 ° C, and the mixture was heated and stirred for 6 hours. Furthermore, 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 lower and stirring is stopped. After filtering with a pole filter, this filtrate was designated as "latex-B".

The resin particles in Latex-B had a glass transition temperature of 58 ° C., a softening point of 132 ° C., a molecular weight distribution of weight average molecular weight = 245,000 and a mass average particle diameter of 11 ° C.
It was 0 nm.

Sodium chloride as a salting-out agent 5.36k
A solution prepared by dissolving g in 20.0 L of ion-exchanged water is referred to as “sodium chloride solution G”.

A solution prepared by dissolving 1.00 g of a fluorine-based nonionic surfactant in 1.00 L of ion-exchanged water is referred to as "nonionic surfactant solution H".

100 L of S equipped with a temperature sensor, a cooling pipe, a nitrogen introducing device, a particle size and shape monitoring device
In the US reactor (the structure of the stirring blade is shown in FIG. 4 (c)), the latex-A = 20.0 kg, the latex-B = 5.2 kg, the colorant dispersion liquid 1 = 0.4 kg, and the ion-exchanged water prepared above were added. Add 20.0 kg and stir. Then, 40
After heating to 0 ° C., sodium chloride solution G, 6.00 kg of isopropanol (manufactured by Kanto Chemical Co., Inc.), and nonionic surfactant solution H are added in this order. Then, after leaving it for 10 minutes, the temperature rise is started and the liquid temperature is raised to 85 ° C. in 60 minutes.
Particle diameter growth is performed while salting out / fusing by heating and stirring at 85 ± 2 ° C. for 0.5 to 3 hours (salting out / fusing step). Next, 2.1 L of pure water is added to stop grain size growth.

5.0 kg of the fused particle dispersion liquid prepared above was placed in a 5 L reaction vessel (a stirring blade configuration is shown in FIG. 4C) equipped with a temperature sensor, a cooling tube, and a particle size and shape monitoring device. 0.5 to 0.5 at the liquid temperature of 85 ℃ ± 2 ℃
The shape was controlled by heating and stirring for 15 hours (shape controlling step).
Then, the temperature is cooled to 40 ° C. or lower and stirring is stopped. Next, using a centrifuge, classification is performed in the liquid by a centrifugal sedimentation method, and the mixture is filtered through a sieve having an opening of 45 μm to obtain the filtrate as an association liquid. Then, using a Nutsche filter, wet cake-like non-spherical particles were collected from the association liquid by filtration. Then, it was washed with ion-exchanged water.

The non-spherical particles were dried at a suction temperature of 60 ° C. using a flash jet dryer, and then at a temperature of 60 ° C. using a fluidized bed dryer. To 100 parts by mass of the obtained colored particles, 1 part by mass of silica fine particles was externally added and mixed by a Henschel mixer to obtain a toner by an emulsion polymerization association method.

In the salting-out / fusion step and shape control step, the shape and the coefficient of variation of the shape coefficient are controlled by controlling the number of revolutions of the stirring blade and the heating time of the liquid temperature. By adjusting the coefficient of variation of the particle size and the particle size distribution by classification, the toners 1-1 to 1-1 shown in Table 3
1-5 was obtained. The composition is styrene / n-butyl acrylate / methacrylic acid = 0.758 / 0.162 / 0.08
It was 0 mol% and the Tg of the resin was about 57 ° C.

Preparation of Toner 2-1 (Example of Emulsion Polymerization Association Method) As in the case of Toner 1-1, in the monitoring of the salting out / fusion step and the shape control step, the stirring rotation speed and heating time should be controlled. To control the variation coefficient of the shape and the shape factor, and further adjust the variation coefficient of the particle size and the particle size distribution by the in-liquid classification, and the toner 2 shown in Table 3 is obtained.
-1 was obtained. Also, the resin composition is styrene of toner 1-1 /
n-butyl acrylate / methacrylic acid = 0.758 /
From 0.162 / 0.080 mol%, styrene / n-butyl acrylate / n-butyl methacrylate = 0.8
Changed to 7 / 0.035 / 0.095 mol%. The Tg of the resin was 67 ° C.

Toners 3-1 to 3-2 (Example of emulsion polymerization association method) In the same manner as Toner 1-1, stirring rotation speed and heating time are controlled in the salting out / fusion step and the shape control step monitoring. In this way, the variation coefficient of the shape and the shape coefficient is controlled, and the variation coefficient of the particle size and the particle size distribution is arbitrarily adjusted by the in-liquid classification.
-1 to 3-2 were obtained. The resin composition is styrene / n-butyl acrylate / n-butyl methacrylate = 0.67.
/0.03/0.30 mol%.

[0242]

[Table 3]

Preparation of Developer Mixing each of the toners 1-1 to 3-2 with a 45 μm ferrite carrier coated with a styrene-methacrylate copolymer at a ratio of 19.8 g of toner and 200.2 g of carrier, respectively. Thus, eight kinds of developers 1-1 to 3-2 corresponding to each toner were prepared.

Evaluation 2 (Evaluation of Image) Konica 7050 (laser digital copying machine manufactured by Konica Corporation: equipped with a cartridge in which a photoconductor, a charger, a developing device, a cleaning device and a charge eliminator are integrated) is attached to photoconductors 1 to 1. No. 18 was mounted and evaluation was carried out by reversal development. The image forming conditions of the charging condition and the cleaning condition were set as follows. Table 4 shows combinations of the photoconductors and the toners (Nos. 1 to 20) used for evaluation.

Charging conditions Charging device: Initial charging potential is -650 V Development condition DC bias: Approximately -500 V Developer layer regulation; Magnetic H-Cut system developing sleeve diameter: 40 mm Transfer pole; Corona charging system, transfer dummy current value: 45 μA Cleaning conditions Elastic rubber blade; free length: 9 mm, thickness: 2 mm,
Hardness: 70 °, impact resilience: 35, photoconductor contact pressure (linear pressure): 15 g / cm Evaluation item As described above, in the combination of the photoconductor and the developer described in Table 4 (No. 1 to 20), Attach the photoconductor and toner,
Under the environment of 30 ° C. and 80% RH, 100,000 copies were actually copied, and the following evaluation items were evaluated.

For copying, an original image in which a character image with a pixel ratio of 7%, a human face photograph, a solid white image, and a solid black image are equally divided into quarters is copied in A4 to obtain a solid white image and a solid black image. Images and thin line images were evaluated.

The criteria for judging each evaluation item are as follows. Crack evaluation The surface of the sample coated up to the intermediate layer was observed to see if cracks occurred. After that, a photoconductor was prepared, 100,000 copies were actually copied under the above environmental conditions, and evaluated according to the following evaluation criteria.

⊚: No cracks are generated in the intermediate layer or fine cracks that do not appear in the image, no problem ○: Minor cracks appearing in the image are generated in the intermediate layer, practically no problem ×: In the intermediate layer Cracks grow and grow on the image,
There is a problem in practical use. Adhesion evaluation After copying 100,000 sheets, film peeling of the photoconductor was evaluated. The evaluation criteria are shown below.

⊚: No film peeling ○: There is slight film peeling at the edges, but not in the image area.
No problem in practical use x: Film peeling occurred in the image area. Practically problematic fog: Judgment by solid white image density For fog, after copying 100,000 sheets, the density of each image was measured for absolute reflection density using RD-918 manufactured by Macbeth. If the increase in residual potential increases, the image density decreases, and if the decrease in charging potential increases, fogging occurs.
Further, if the uniformity of the charging potential decreases, the image unevenness increases.

⊚: Solid white image density is less than 0.005 (good) ◯: Solid white image density is 0.005 or more and less than 0.01 (no problem in practical use) ×: 0.01 or more (problem in practical use) Sharpness: Judgment by fine line image Sharpness was visually judged after the number of fine lines per 1 mm that can be discriminated by the copy image of the fifth generation was prepared after copying 100,000 sheets.

⊚: 6 lines / mm or more (good) O: 4 lines / mm or more and 5 lines / mm or less (at a level where there is no practical problem) ×: 3 lines / mm or less (with practical problem) Image unevenness: 100,000 0.4 after copying the original image
Copy the halftone image of the density of 0.4 to the density of 0.4, and judge by the density difference of the copied images (ΔHD = maximum density−minimum density) ◎: ΔHD is 0.05 or less (good) ○: ΔHD is more than 0.05 Larger than 0.1 (no problem in practical use) ×: ΔHD is 0.1 or more (problem in practical use) Black spots Black spots have a major axis of 0.4 m after 100,000 copies.
It was judged by the number of black spots of m or more per A4 sheet.
The major axis of the black spot can be measured with a microscope equipped with a video printer.

⊚: Black spot frequency of 0.4 mm or more: All copied images were 3
No./A4 or less ○: 0.4 mm or more black spot frequency: 4 / A4 or more, 1
9 or more / A4 or less occurred 1 or more (no problem in practical use) ×: Black spot frequency of 0.4 mm or more: 20 / A4 or more occurred 1 or more (problem in practical use) Evaluation results are shown in Table 4. .

[0253]

[Table 4]

From Tables 2 and 4, the photoconductors 2 to 7 of the present invention having the intermediate layer in which the intermediate layer of the present invention contains N-type semiconductive particles to form a Benard cell (N in combination No.
o. 2 to No. 7) and 9 to 16 (No. 9 to No. 16 in the combination No.), the adhesiveness of the intermediate layer is good, the occurrence of cracks is suppressed, and good characteristics are obtained in image evaluation. On the other hand, in the photoconductor 18 (combination No. 18) using the intermediate layer formed only from the binder other than the present invention, Benard cells are not formed, and as a result, black spots and image unevenness often occur, Sharpness is also decreasing. On the other hand, even if the intermediate layer has N-type semiconducting particles, black spots are remarkably generated in the photoconductor 8 (combination No. 8) having a surface roughness Rz of the substrate of 2.5 μm. Photoreceptor 1 (combination No. 1), which is thin and has no Benard cells, has poor adhesion.
Fog and black spots are also noticeable. Intermediate layer photoreceptor 18 using silica particles (non-semiconductive particles) (combination number.
Also in 18), the occurrence of Benard cells is weak, the occurrence of cracks in the intermediate layer is large, and the occurrence of black spots is large. Further, in the combination of the photoconductor and the toner, even if the photoconductor of the present invention is used, the variation of the shape factor of the toner is larger than 16% (combination No. 19), and the number variation coefficient of the number particle size distribution is 27. In the combination (combination No. 20) larger than%, the sharpness is slightly lowered.

[0255]

The surface roughness Rz of the conductive support is 0.2 to.
The photoreceptor of the present invention having a thickness of 2.0 μm and containing N-type semiconducting particles and having an intermediate layer in which a Benard cell is formed improves the adhesiveness between the support and the intermediate layer or the photosensitive layer, and reverse development. An electrophotographic image having a remarkable effect of improving the occurrence of black spots, which is peculiar to, and having excellent sharpness is provided. Further, a good electrophotographic image can be provided by using the image forming method, the image forming apparatus, and the process cartridge in which the photosensitive member is combined with the toner having a small variation in shape coefficient and particle size distribution.

[Brief description of drawings]

FIG. 1A is an explanatory diagram showing a projected image of toner particles without corners, and FIGS. 1B and 1C are explanatory diagrams showing projected images of toner particles with corners.

FIG. 2 is a perspective view showing an example of a polymerized toner reaction device.

FIG. 3 is a cross-sectional view showing an example of a polymerized toner reaction device.

FIG. 4 is a schematic view showing a specific example of the shape of a stirring blade.

FIG. 5 is a sectional view of an image forming apparatus as an example of an image forming method of the present invention.

FIG. 6 is a diagram in which a large number of polygons are formed in front, back, left and right (Benard cell structure).

[Explanation of symbols]

50P photoconductor drum (or photoconductor) 51 Pre-charge exposure unit 52 Charger 53 Image exposure device 54 Developer 541 Development sleeve 543,544 developer stirring and conveying member 547 potential sensor 57 Paper Feed Roller 58 transfer electrode 59 Separation electrode (separator) 60 fixing device 61 Paper ejection roller 62 cleaning device 70 Process cartridge

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 9/087 G03G 9/08 325 (72) Inventor Shinichi Hamaguchi 1st Sakura Town, Hino City, Tokyo Konica Stock Association In-house F-term (reference) 2H005 AA01 AB06 CA04 EA05 EA10 2H068 AA43 AA44 AA48 AA59 BA58 BB28 CA06 CA29 CA33 CA60 FA08 FA27 FA30

Claims (24)

[Claims] 1. An electrophotographic photosensitive member having an intermediate layer between a conductive support and a photosensitive layer, wherein the conductive support has a surface roughness Rz of 0.2 to 2.0 μm, and the intermediate layer has N. An electrophotographic photoreceptor comprising an insulating layer containing type semiconductive particles and a binder, and having a Benard cell formed therein. 2. The N-type semiconductor particles are subjected to surface treatment a plurality of times, and the final surface treatment is a surface treatment with a reactive organosilicon compound.
The electrophotographic photosensitive member according to 1. 3. The electrophotographic photosensitive member according to claim 2, wherein the reactive organosilicon compound is methylhydrogenpolysiloxane. 4. The electrophotographic photosensitive member according to claim 2, wherein the reactive organosilicon compound is an organosilicon compound represented by the following general formula (1). General formula (1) R-Si- (X) ₃ (R is an alkyl group, an aryl group, X is a methoxy group, an ethoxy group, a halogen group.) 5. R in the general formula (1) has 4 to 8 carbon atoms.
The electrophotographic photosensitive member according to claim 4, wherein the electrophotographic photosensitive member is an alkyl group up to 6. The surface treatment of at least one of the plurality of surface treatments is a surface treatment of one or more compounds selected from alumina, silica, and zirconia. The electrophotographic photosensitive member according to any one of 1. 7. The electrophotographic photosensitive member according to claim 1, wherein the N-type semiconductor particles are surface-treated with an organic silicon compound having a fluorine atom. 8. The N-type semiconducting particles have a number average primary particle size of 1
The electrophotographic photosensitive member according to claim 1, wherein the electrophotographic photosensitive member is a particle having a size of 0 nm or more and 200 nm or less. 9. The electrophotographic photosensitive member according to claim 1, wherein the N-type semiconductive particles are metal oxide particles. 10. The electrophotographic photosensitive member according to claim 9, wherein the metal oxide particles are titanium oxide particles. 11. The electrophotographic photosensitive member according to claim 1, wherein the binder of the intermediate layer is a polyamide resin. 12. The dry film thickness of the intermediate layer is 0.2 to 15 μm.
m is any one of Claims 1-11 characterized by the above-mentioned.
The electrophotographic photosensitive member according to the item. 13. The surface roughness Rmax of the intermediate layer is 0.
2 to 3.0 μm.
The electrophotographic photosensitive member according to any one of 1. 14. An image forming method in which an electrophotographic photosensitive member is rotated, and at least charging, exposure, development using a toner, and transfer are repeated, wherein the electrophotographic photosensitive member is formed.
3. The electrophotographic photosensitive member according to any one of 2 above, wherein the toner has a variation coefficient of shape factor of 16% or less and a variation coefficient of number in number particle size distribution of 27% or less. Image forming method. 15. The toner has a shape factor of 1.0 to 1.
15. The image forming method according to claim 14, wherein the number of toner particles in the range of 6 is 65% by number or more. 16. The toner has a shape factor of 1.2 to 1.
16. The image forming method according to claim 15, further comprising 65% by number or more of toner particles in the range of 6. 17. The toner according to claim 14, wherein the toner contains 50% by number or more of toner particles having no corners.
17. The image forming method according to any one of 16. 18. The number average particle diameter of the toner is 3 to 8 μm.
The image forming method according to any one of claims 14 to 17, wherein m is m. 19. When the particle diameter of the toner particles is D (μm), the natural logarithm lnD is plotted on the horizontal axis, and the horizontal axis indicates a number-based particle size distribution divided into a plurality of classes at 0.23 intervals. The sum (M) of the relative frequency (m ₁ ) of the toner particles included in the most frequent class in the histogram and the relative frequency (m ₂ ) of the toner particles included in the next most frequent class is 70. % Or more, Claim 1 characterized by the above-mentioned.
The image forming method according to any one of 4 to 18. 20. The image forming method according to claim 14, wherein the toner is obtained from colored particles obtained by polymerizing at least a polymerizable monomer in an aqueous medium. . 21. The image forming method according to claim 14, wherein the toner is obtained from colored particles obtained by associating at least resin particles in an aqueous medium. 22. The toner according to claim 14, wherein the toner is a styrene- (meth) acrylate resin.
1. The image forming method according to any one of 1. 23. An image forming apparatus using the image forming method according to any one of claims 14 to 22. 24. The electrophotographic photosensitive member according to claim 1, and at least a charging unit, an image exposing unit,
A process cartridge characterized in that any one of a developing means and a cleaning means is integrally combined, and can be freely taken in and out of an image forming apparatus.