JP2002244324A - Image forming method, image forming device and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming method, an image forming device and a process cartridge having high offset property and fixing ability, made excellent in developing ability and definition, preventing the occurrence of a black spot and fogging irregularity, made good in cleaning ability and adhesiveness and stably possessing high image quality performance even in long-term use. SOLUTION: This image forming method includes a developing stage where an electrostatic latent image formed on an electrophotographic sensitive body having a photoreceptive layer on a conductive supporting body through an intermediate layer is developed with toner for developing an electrostatic charge image incorporating at least resin and colorant. The intermediate layer of the sensitive body is a layer incorporating at least either an organic metallic compound or a silane coupling agent, and toner whose variance coefficient of a shape factor is <=16% and whose number variance coefficient in number particle distribution is <=27% is used as the toner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method, an image forming apparatus, and a process cartridge used for a copying machine, a printer, and the like.

[0002]

2. Description of the Related Art At present, most image forming apparatuses that require high-speed and high-quality images employ an image forming method in which an electrostatic latent image is formed on an electrophotographic photosensitive member and developed with dry toner. I have.

The reason is that high-quality images can be formed at high speed, the performance is stable even when used for a long period of time, and color images can be formed. Therefore, it is considered that this field will continue to occupy a large area in the future, but it is also true that there are some demands for improving the performance. The biggest among them is further improvement in image quality.

The most effective countermeasures in studying high image quality are to reduce the particle size of the toner and to make the shape and surface properties of the toner uniform, and many technical studies have been made at present. .

[0005] The typical inventions developed therein include, for example, the following. The use of toner composed of toner particles having a shape coefficient variation coefficient of 16% or less and a number variation coefficient of 27% or less in the number particle size distribution (hereinafter, also referred to as “toner A”) allows an offset resistance. This improves the developing property and the fixing property, and is excellent in developing property and fine line reproducibility, and can form a high-quality image for a long time.

[0006] Further, since the toner particles having no corners have a smooth (smooth) surface and promote the fusion of the toner particles to each other, the same effect can be obtained even if the variation in shape is somewhat large. That is, the ratio of toner particles having no corners is 50% by number.
The number variation coefficient in the number particle size distribution is 27
% Or less of toner particles (hereinafter, referred to as
By using “toner B”), the anti-offset property and the fixing property are improved, the developing property and the fine line reproducibility are excellent, and a high-quality image can be formed for a long period of time.

Further, when the shape of the toner particles is made specific and the shapes are made uniform, the packing density of the toner particles in the toner layer is increased and the voids are reduced.
There is a similar effect. That is, when the shape factor is 1.2 to 1.
The toner composed of toner particles having a ratio of the toner particles in the range of 6 to 65% by number or more and a coefficient of variation of the shape coefficient of 16% or less (hereinafter also referred to as “toner C”)
By using, the anti-offset property and the fixing property are improved, the developing property and the fine line reproducibility are excellent, and a high-quality image can be formed for a long time.

[0008]

The above-mentioned toner A,
B and C have high offset resistance and fixing property,
Development has been promoted in order to form a high-quality image with excellent sharpness (fine line reproducibility) over a long period of time. However, it has been found that there are some problems.

That is, although the sharpness is good, it has been found that the amount of depletion is slightly large especially under high temperature and high humidity, and that when the photosensitive layer becomes about 15 μm, black spots increase sharply. In addition, the potential stability under high temperature and high humidity is poor, and fog unevenness tends to occur,
When durability of tens of thousands or more copies is required, the above advantage is not utilized.

Further, when the toner particle diameter is reduced and made uniform, the adhesion to the latent image forming member (electrophotographic photosensitive member) is high, so that the torque at the time of cleaning tends to be excessive, and the toner is removed by a cleaning blade. The cleaning layer has a high probability of slipping through, causing poor cleaning. Under high temperature and high humidity, the adhesiveness of the intermediate layer is weak, and the film peels off at the end of the photoconductor drum. And the occurrence of poor cleaning has also been a problem.

An object of the present invention is to find a method for improving black spots, fog spots, cleaning properties, adhesiveness, etc. while ensuring sharpness with the toner having the specific shape as described above. An object of the present invention is to provide an image forming method, an image forming apparatus, and a process cartridge having image quality performance.

[0012]

As a result of intensive studies, the present inventors have found that in order to improve the above-mentioned problems, a curable type photoconductor (sometimes simply referred to as a photoconductor) is used as an intermediate layer. It has been found that the use of the intermediate layer enables the photosensitive layer to be used without deteriorating its performance even when the thickness of the photosensitive layer is reduced to about 15 μm, and to overcome the above-mentioned disadvantages.

That is, the object of the present invention is achieved by adopting one of the following constitutions. [1] An electrostatic latent image formed on an electrophotographic photoreceptor having a photosensitive layer on a conductive support via an intermediate layer is formed by an electrostatic image developing toner containing at least a resin and a colorant. In an image forming method including a developing step of developing a visible image, the intermediate layer of the photoreceptor is a layer containing at least one of an organometallic compound and a silane coupling agent, and the toner has a shape coefficient variation coefficient of 16 % Or less, and a toner having a number variation coefficient of 27% or less in a number particle size distribution is used.

[2] The image forming method according to [1], wherein the organic metal compound contained in the intermediate layer is a metal alkoxide or an organic metal chelate.

[3] The image forming method according to [1], wherein the intermediate layer is a layer containing an organic metal chelate and a silane coupling agent.

[4] The image forming method according to any one of [1] to [3], wherein the organometallic chelate contained in the intermediate layer is represented by the general formula (1).

[5] The image forming apparatus according to any one of [1] to [4], wherein the silane coupling agent contained in the intermediate layer is represented by the general formula (2). Method.

[6] The image forming method according to any one of [1] to [5], wherein the photosensitive layer contains a hindered amine or a hindered phenol compound.

[7] From 1.0 to 1.0 of the shape factor of the toner
The image forming method according to any one of [1] to [6], wherein the ratio of the toner particles in the range of 1.6 is 65% by number or more.

[8] From 1.2 to the shape factor of the toner
The image forming method according to any one of [1] to [6], wherein the ratio of the toner particles in the range of 1.6 is 65% by number or more.

[0021]

[9] The ratio of the toner particles having no corners of the toner is 50% by number or more [1].
-The image forming method according to any one of [8].

[10] The number average particle diameter of the toner particles is 3 to 8 μm.

The image forming method according to any one of [9].

[11] The particle diameter of the toner particles is D (μ
m), the natural logarithm lnD is plotted on the horizontal axis, and in the histogram showing the number-based particle size distribution divided into a plurality of classes at intervals of 0.23, the relative frequency of the toner particles contained in the most frequent class (M1) and the relative frequency (m) of the toner particles included in the class having the highest frequency next to the mode.
The image forming method according to any one of [1] to [10], wherein the sum (M) of 2) is not less than 70%.

[12] The image forming method according to any one of [1] to [11], wherein the toner is obtained by polymerizing at least a polymerizable monomer in an aqueous medium.

[13] The image forming method according to any one of [1] to [12], wherein at least the resin particles of the toner are obtained by being associated in an aqueous medium.

[14] An electrostatic latent image formed on an electrophotographic photosensitive member having a photosensitive layer on a conductive support via an intermediate layer is developed into an electrostatic image containing at least a resin and a colorant. In an image forming method including a developing step of visualizing with a toner for use, the intermediate layer is a layer containing at least one of an organometallic compound and a silane coupling agent, and the toner has a ratio of toner particles having no corners. Is 50% by number or more and a number variation coefficient in the number particle size distribution is 27% or less.

[15] 1.0 of the shape factor of the toner
The image forming method according to [14], wherein the ratio of the toner particles in the range of 1.6 to 1.6 is 65% by number or more.

[16] 1.2 of the shape factor of the toner
The image forming method according to [14], wherein the ratio of the toner particles in the range of 1.6 to 1.6 is 65% by number or more.

[17] The number average particle diameter of the toner particles is 3 to 8 μm.
6] The image forming method according to any one of the above.

[18] The particle diameter of the toner particles is D (μ
m), the natural logarithm lnD is plotted on the horizontal axis, and in the histogram showing the number-based particle size distribution divided into a plurality of classes at intervals of 0.23, the relative frequency of the toner particles contained in the most frequent class (M1) and the relative frequency (m) of the toner particles included in the class having the highest frequency next to the mode.
The image forming method according to any one of [14] to [17], wherein the sum (M) of 2) is 70% or more.

[19] The image forming method according to any one of [14] to [18], wherein the toner is obtained by polymerizing at least a polymerizable monomer in an aqueous medium.

[20] The image forming method according to any one of [14] to [19], wherein the toner is obtained by associating at least resin particles in an aqueous medium.

[21] An electrostatic latent image formed on an electrophotographic photosensitive member having a photosensitive layer on a conductive support via an intermediate layer is developed into an electrostatic image containing at least a resin and a colorant. In an image forming method including a developing step of visualizing with a toner for use, the intermediate layer is a layer containing at least one of an organometallic compound and a silane coupling agent, and the toner has a shape factor of 1.2 to 1 6. An image forming method using a toner having a ratio of toner particles in a range of 65% by number or more and a shape coefficient variation coefficient of 16% or less.

[22] The ratio of the toner particles having no corners of the toner is 50% by number or more [2].
The image forming method according to 1).

[23] The toner according to [21] or [2], wherein the number average particle diameter of the toner particles is 3 to 8 μm.
The image forming method according to 2).

[24] The particle size of the toner particles is D (μ
m), the natural logarithm lnD is plotted on the horizontal axis, and in the histogram showing the number-based particle size distribution divided into a plurality of classes at intervals of 0.23, the relative frequency of the toner particles contained in the most frequent class (M1) and the relative frequency (m) of the toner particles included in the class having the highest frequency next to the mode.
The image forming method according to any one of [21] to [23], wherein the sum (M) of 2) is not less than 70%.

[25] The image forming method according to any one of [21] to [24], wherein the toner is obtained by polymerizing at least a polymerizable monomer in an aqueous medium.

[26] The image forming method according to any one of [21] to [25], which is obtained by associating at least resin particles of the toner in an aqueous medium.

[27] An image forming apparatus using the image forming method according to any one of [1] to [26].

[28] The image forming method according to any one of [1] to [26], wherein a photosensitive member, a charger, an image exposing unit, a developing unit, a transferring unit, a separating unit and a cleaning unit are used. A process cartridge characterized by being manufactured by combining at least one of them.

[0041]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in more detail.

<Intermediate Layer Used in the Present Invention> Next, the photoreceptor of the present invention is used to secure excellent image quality and adhesiveness when an image is formed by providing a photosensitive layer on a conductive support. It is characterized in that an intermediate layer containing at least one of an organometallic compound and a silane coupling agent is provided between the conductive support and the photosensitive layer.

<< Organic metal compound, silane coupling >>
Examples of the organometallic compound contained in the intermediate layer of the photoreceptor of the present invention include alkoxide compounds such as zirconium tetra-n-propylate, aluminum isopropylate, mono-sec-butoxyaluminum-i-propylate, and aluminum-sec-butylate. And a group 1a, a group 1b, or a group 2a of the periodic table.
Group, group 3a, group 3b, group 4a, group 4b, group 5a
3, 4, 6, 8 with a metal atom selected from Group 5, 5b and Group 8 and acetoacetate, β-diketone, acetylacetone, catechol, ethylenediamine, o-phenylenebisdimethylaniline and the like as chelating agents
An organic metal chelate compound which is molecularly coordinated in the range of the molecule may be used.

However, in the intermediate layer of the photoreceptor of the present invention, the organometallic chelate compound represented by the general formula (1) is used as the organometallic compound, and the silane coupling agent represented by the general formula (2) is used. Is preferably contained in combination.

In the general formula (1), R ₁ is a lower alkyl group, M represents a metal atom such as zirconium, titanium or aluminum, and the chelating group K represents an acetoacetic ester group or a β-diketone residue. , G, m
Represents an integer of 1 or more. However, when M is zirconium or titanium, g + m is 4, and when M is aluminum, g + m is 3.

Specific examples of the organometallic chelate compound represented by the general formula (1) include, for example, diisopropoxytitanium (methylacetoacetate) isobutoxytitanium tri (methylacetoacetate) tributoxytitanium acetylacetate Nitrate diisopropoxyaluminum (methylacetoacetonate) dibutoxytitanium bis (ethylacetoacetonate) isobutoxyaluminum (acetylacetonate) and the like.

Next, in the silane coupling agent represented by the general formula (2), Q represents a halogen atom, a lower alkoxy group or an amino group which may have a substituent, and A represents a lower alkyl group or a phenyl group. Or an aryl group such as a naphthyl group, and the organic functional group Y is -BOOC (R ')
C = CH ₂ , —BNHR ″ or —BNH _2. R ′ represents a lower alkyl group; R ″ represents a lower alkyl group or an aryl group such as a phenyl group or a naphthyl group;
Is a lower alkylene group or -O-, -NH-, -CO-
Represents a lower alkylene group containing p and q represent an integer of 1 or more, r represents an integer of 0 or more, and p + q + r is 4.

Specific examples of the silane coupling agent represented by the general formula (2) include, for example, γ-methacryloxypropyltrimethoxysilane γ-methacryloxypropyltriethoxysilane γ-methacryloxypropylmethyldimethoxysilane Etc. can be given.

In the present invention, the thickness of the intermediate layer is from 0.1 to
10 μm is preferable, and particularly preferably 0.1 to 5 μm.

<< Antioxidant added to the surface layer >>
In the present invention, it is preferable to include an antioxidant in the surface layer in order to sufficiently prevent the electrophotographic performance of the photoreceptor from fatigue deterioration in the course of repeated image formation, particularly a hindered amine, a hindered phenol compound, It is preferable to contain a phosphorus compound or a sulfur compound.

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

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

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

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

[0055]

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R ₁₃ in the formula is a hydrogen atom or a monovalent organic group,
R ₁₄ , R ₁₅ , R ₁₆ and R _{17 each} represent an alkyl group, and R ₁₈ represents a hydrogen atom, a hydroxyl group or a monovalent organic group.

Examples of the antioxidant having a hindered phenol partial structure include compounds described in JP-A-1-118137 (P7 to P14), but the present invention is not limited thereto.

As an antioxidant having a hindered amine partial structure, for example, JP-A-1-118138 (P.
7 to P9), but the present invention is not limited thereto.

The following are examples of typical antioxidant compounds.

[0060]

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[0061]

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[0062]

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As the organic phosphorus compound, for example,
A compound represented by the general formula RO-P (OR) -OR is a representative one. Here, R represents a hydrogen atom, a substituted or unsubstituted alkyl group, alkenyl group or aryl group.

Further, examples of the organic sulfur compound include a compound represented by the general formula RSR. Here, R represents a hydrogen atom, a substituted or unsubstituted alkyl group, alkenyl group or aryl group.

Examples of the antioxidants that have been commercialized include the following compounds, for example, “Irganox 107”.
6, Irganox 1010, Irganox 1098, Irganox 245, Irganox 1330, Irganox 3114, Irganox 1076, 3,5-di-t-butyl- 4
-Hydroxybiphenyl "or more hindered phenols," Sanol LS2626 "," Sanol LS76 "
5, "Sanol LS770", "Sanol LS74"
4, "Tinuvin 144", "Tinuvin 622LD",
"Mark LA57", "Mark LA67", "Mark L
A62 "," mark LA68 ", and" mark LA63 "or more.

<Layer Structure of Photoreceptor> The layer structure of the photoreceptor of the present invention comprises a charge generation material (CG) on a conductive support via an intermediate layer.
M) -containing charge generation layer (CGL), a charge transport layer (CTL) containing a charge transport substance (CTM), and a surface layer (as a protective layer) may be provided in this order, or via an intermediate layer. CGL containing CGM and surface layer (C
TL) may be provided in this order, or a surface layer (as a photosensitive layer) containing CGM may be provided via an intermediate layer. Further, CGM may be provided via an intermediate layer.
And a photosensitive layer and a surface layer (as a protective layer) containing both CTM and CTM may be provided in this order.

However, in the present invention, from the viewpoint of practicability, a structure in which CGL containing CGM, CTL containing CTM, and a surface layer (as a protective layer) are provided in this order on a conductive support via an intermediate layer. Is particularly important.

<< CGM and CTM contained in the photosensitive layer >> Examples of the CGM contained in the photosensitive layer of the present invention include phthalocyanine pigments, polycyclic quinone pigments, azo pigments, perylene pigments, indigo pigments, quinacridone pigments, and azurenium pigments. And squarylium dyes, cyanine dyes, pyrylium dyes, thiopyrylium dyes, xanthene dyes, triphenylmethane dyes, styryl dyes, and the like. These CGMs are used alone or in combination with an appropriate binder resin to form a layer.

As the CTM contained in the photosensitive layer,
For example, oxazole derivatives, oxadiazole derivatives,
Thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives,
Imidazoline derivatives, bisimidazolidine derivatives, styryl compounds, hydrazone compounds, benzidine compounds, pyrazoline derivatives, stilbene compounds, amine derivatives, oxazolone derivatives, benzothiazole derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran derivatives, acridine derivatives, phenazine derivatives, amino Examples include stilbene derivatives, poly-N-vinylcarbazole, poly-1-vinylpyrene, poly-9-vinylanthracene, and the like. In these CTMs, a layer is usually formed together with a binder resin.

<< Binder Resin of Photosensitive Layer >> As the binder resin contained in the single-layered photosensitive layer and the CGL and CTL in the case of the laminated structure, polycarbonate resin, polyester resin, polystyrene resin, methacrylic resin,
Acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl butyral resin, polyvinyl acetate resin, styrene-butadiene resin, vinylidene chloride-acrylonitrile copolymer resin, vinyl chloride-maleic anhydride copolymer resin, urethane resin, silicone Resins, epoxy resins, silicone-alkyd resins, phenol resins, polysilane resins, polyvinyl carbazole, and the like.

In the present invention, the ratio of CGM to binder resin in CGL is preferably from 1: 5 to 5: 1 by mass. The thickness of the CGL is preferably 5 μm or less, particularly preferably 0.05 to 2 μm.

The CTL is formed by dissolving the CTM and the binder resin in an appropriate solvent, and applying and drying the solution. The mixing ratio of CTM and the binder resin is preferably from 3: 1 to 1: 3 by mass ratio.

The thickness of the CTL is preferably 5 to 50 μm, particularly preferably 10 to 40 μm. When a plurality of CTLs are provided, the thickness of the upper layer of the plurality of CTLs is preferably 10 μm or less. It is preferable that the thickness be smaller than the thickness of all the CTLs provided under the plurality of CTLs.

<< Solvent and Dispersant for Photosensitive Layer >> As the solvent or dispersant used for the photosensitive layer, intermediate layer and protective layer of the photoreceptor of the present invention, n-butylamine, diethylamine, ethylenediamine, isopropanolamine, Ethanolamine, triethylenediamine, N, N-dimethylformamide, acetone, methyl ethyl ketone, methyl isopropyl ketone, cyclohexanone, benzene, toluene, xylene, chloroform, dichloromethane,
1,2-dichloroethane, 1,2-dichloropropane,
1,1,2-trichloroethane, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethane,
Tetrahydrofuran, dioxolan, dioxane, methanol, ethanol, butanol, isopropanol,
Ethyl acetate, butyl acetate, dimethyl sulfoxide, methyl cellosolve and the like can be mentioned. Although the present invention is not limited to these, dichloromethane, 1,2-dichloroethane, methyl ethyl ketone and the like are preferably used. In addition, these solvents can be used alone or as a mixed solvent of two or more kinds.

<< Conductive Support >> Next, the conductive support of the electrophotographic photoreceptor of the present invention includes: 1) a metal plate such as an aluminum plate or a stainless plate, or 2) a support such as paper or a plastic film. ,
A thin metal layer such as aluminum, palladium, or gold provided by lamination or vapor deposition. 3) On a support such as paper or plastic film,
A conductive polymer, a layer provided with a conductive compound such as indium oxide, tin oxide or the like by coating or vapor deposition; 4) alumite, particularly a sealed anodized substrate;

The material of the conductive support used in the present invention is mainly aluminum, copper, brass, steel,
A belt-shaped or drum-shaped metal material such as stainless steel or another plastic material is used. Among them, aluminum excellent in cost, workability and the like is preferably used, and a thin-walled cylindrical aluminum tube usually formed by extrusion or drawing is often used.

The shape of the support may be a drum shape, a sheet shape, or a belt shape, and may be any shape suitable for the applied electrophotographic apparatus.

<< Coating Method >> Next, as a coating method for producing the electrophotographic photoreceptor of the present invention, coating methods such as dip coating, spray coating, and circular amount control type coating are used. The coating process on the surface layer side of the layer does not dissolve the lower layer film as much as possible, and in order to achieve a uniform coating process, a coating process such as a spray coating or a circular volume control type (a typical example is a circular slide hopper type). It is preferable to use The spray coating is described in detail in, for example, JP-A-3-90250 and JP-A-3-269238, and the circular amount control type coating is described in detail in, for example, JP-A-58-189061. I have.

In the present invention, a coating for compensating for surface defects of the support is provided between the support and the intermediate layer. A conductive layer for the purpose of preventing generation and the like can be provided. This conductive layer is made of carbon black,
It can be formed by applying and drying a solution in which conductive powder such as metal particles or metal oxide particles is dispersed in a suitable binder resin. The thickness of the conductive layer is preferably 5 to 40 μm, particularly preferably 10 to 30 μm.

<Toner used in the present invention> The toner A used in the present invention is composed of toner particles having a shape coefficient variation coefficient of 16% or less and a number variation coefficient in the number particle size distribution of 27% or less. You. In the toner B used in the present invention, the ratio of toner particles having no corners is 50% by number.
The number variation coefficient in the number particle size distribution is 27
% Or less. The toner C used in the present invention is composed of toner particles having a shape coefficient in the range of 1.2 to 1.6 in which the proportion of toner particles is 65% by number or more and the coefficient of variation in shape coefficient is 16% or less. Is done.

<< Shape Coefficient of Toner >> The “shape coefficient” of the toner of the present invention is represented by the following equation, and indicates the degree of roundness of toner particles.

Shape factor = ((maximum diameter / 2) ² × π) / projected area Here, the maximum diameter is defined as the parallel image obtained when a projected image of a toner particle on a plane is sandwiched between two parallel lines. Means the width of the particle at which the distance between the particles becomes maximum. The projection area refers to the area of the projected image of the toner particles on the plane. In the present invention, the shape factor can be determined by taking a photograph in which the toner particles are magnified 2,000 times with a scanning electron microscope, and then referring to the “SCCANNING IMAGE ANALYZE” based on the photograph.
R "(manufactured by JEOL Ltd.) was used to analyze photographic images. In this case, the shape factor of the present invention was measured by using the above formula using 100 toner particles.

In the toner A and the toner B according to the present invention, the ratio of the toner particles having the shape coefficient in the range of 1.0 to 1.6 is preferably 65% by number or more, more preferably 70% by number. % Or more. More preferably, the ratio of the toner particles whose shape factor is in the range of 1.2 to 1.6 is 65% by number or more, and more preferably 70% by number or more. If the shape factor is 1.
The ratio of toner particles in the range of 0 to 1.6 is 65% by number
Due to the above, the filling density of the toner particles in the toner layer transferred to the transfer material is increased, the fixing property is improved, and the offset hardly occurs. Further, the toner particles are less likely to be crushed, so that the contamination of the charging member is reduced, and the charging property of the toner is stabilized.

In the toner C of the present invention, the ratio of the toner particles whose shape factor is in the range of 1.2 to 1.6 is 6
It is necessary to be 5% by number or more, preferably 7%.
0% by number or more.

The method for controlling the shape factor is not particularly limited. For example, a method of spraying toner particles in a hot air flow, a method of repeatedly applying mechanical energy by an impact force in a gaseous phase in a gas phase, a method of adding a toner in a solvent that does not dissolve a toner and imparting a swirling flow, etc. A method of preparing toner particles having a shape factor of 1.0 to 1.6 or 1.2 to 1.6, and adding the particles to a normal toner so as to fall within the range of the present invention. is there.

In the stage of preparing a so-called polymerization toner, the overall shape is controlled, and the toner particles whose shape factor is adjusted to 1.0 to 1.6 or 1.2 to 1.6 are similarly used in ordinary toner. There is a method of adding to and adjusting the amount. Among the above methods, a polymerization toner is preferred because it is simple as a production method and has excellent surface uniformity as compared with a pulverized toner.

<< Coefficient of Variation of Shape Factor of Toner >> The “coefficient of variation of shape coefficient” of the toner of the present invention is calculated from the following equation.

Coefficient of variation (%) = (S ₁ / K) × 100 (where S ₁ represents the standard deviation of the shape coefficients of 100 toner particles, and K represents the average value of the shape coefficients). In the toners A and C of the present invention, the coefficient of variation of the shape factor is 16% or less, and preferably 14% or less. When the variation coefficient of the shape factor is 16% or less, the gap of the transferred toner layer (powder layer) is reduced, the fixing property is improved, and the offset is less likely to occur. Further, the charge amount distribution becomes sharp, and the image quality is improved.

In order to uniformly control the shape factor of the toner and the variation coefficient of the shape factor without extremely varying lots, resin particles (polymer particles) constituting the toner of the present invention are prepared (polymerized). In the step of fusing the particles and controlling the shape, an appropriate process end time may be determined while monitoring the characteristics of the toner particles (colored particles) being formed. Monitoring means that a measuring device is incorporated in-line and process conditions are controlled based on the measurement result. That is, for example, in the case of a polymerization toner formed by incorporating measurement of shape and the like inline and assembling or fusing resin particles in an aqueous medium, the shape and particle size are sequentially measured in a process such as fusing. Is measured, and the reaction is stopped when the desired shape is obtained. Although the monitoring method is not particularly limited, the flow type particle image analyzer F
PIA-2000 (manufactured by Toa Medical Electronics Co., Ltd.) can be used. This apparatus is suitable because the shape can be monitored by performing image processing in real time while passing the sample liquid. In other words, using a pump etc. from the reaction field, constantly monitor and measure the shape etc.,
The reaction is stopped when a desired shape or the like is obtained.

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

Coefficient of number variation (%) = (S _{2 /} D _n ) × 100 (where S ₂ represents a standard deviation in the number particle size distribution,
D _n denotes the number average particle diameter ([mu] m). The number variation coefficient of the toners A and B of the present invention is 27.
% Or less, preferably 25% or less. When the number variation coefficient is 27% or less, voids in the transferred toner layer (powder layer) are reduced, so that the fixing property is improved, and offset is less likely to occur. Further, the charge amount distribution is sharpened, the transfer efficiency is increased, and the image quality is improved.

The method for controlling the number variation coefficient in the toner of the present invention is not particularly limited. For example, a method of classifying toner particles by wind force can be used, but classification in a liquid is effective for further reducing the number variation coefficient. As a method of classifying in a liquid, there is a method of separating and collecting toner particles according to a sedimentation speed difference caused by a difference in toner particle diameter by controlling a rotation speed by using a centrifugal separator. Particularly, when a toner is produced by a suspension polymerization method, the number variation coefficient in the number particle size distribution is 27%.
A classification operation is essential to achieve the following. In the suspension polymerization method, it is necessary to disperse a polymerizable monomer into oil droplets of a desired size as a toner in an aqueous medium before polymerization. That is, mechanical shearing by a homomixer, a homogenizer, or the like is repeated on a large oil droplet of the polymerizable monomer to reduce the oil droplet to the size of toner particles. In the method by the appropriate shearing, the number particle size distribution of the obtained oil droplets becomes broad,
Therefore, the particle size distribution of the toner obtained by polymerizing the polymer becomes wide. For this reason, a classification operation is required.

<< Ratio of toner particles having no corners >> In the toner particles constituting the toner B of the present invention, the ratio of the toner particles having no corners needs to be 50% by number or more, and this ratio is 70% by number. It is preferable that it is above. In the toner particles constituting the toners A and C of the present invention, the ratio of the toner particles having no corners is preferably 50% by number or more, more preferably 70% by number or more.

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

Here, “toner particles having no corner” refers to toner particles having substantially no projections on which electric charges are concentrated or projections which are easily worn by stress.
Specifically, the following toner particles are referred to as toner particles having no corners.

FIG. 1 is a diagram for explaining a toner particle having no corner and a toner particle having a corner. As shown in FIG. 1A, when the major axis of the toner particles T is L, the radius (L /
In the circle of 10), when the inside is rolled while contacting the inside at one point with respect to the peripheral line of the toner particle T, the circle becomes the toner T
The case where the toner does not substantially protrude from the outside is called "toner particles having no corners". “Cases that do not substantially protrude” refer to cases where there are no more than one protrusion having a protruding circle. Further, “the major axis of the toner particles” refers to the width of the particle at which the interval between the parallel lines is the largest when the projected image of the toner particles on the plane is sandwiched between two parallel lines. FIGS. 1B and 1C show projected images of the toner particles having corners, respectively.

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

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

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

<< Particle Particle Size of Toner >> The particle size of the toner of the present invention is preferably 3 to 8 μm in number average particle size. In the case where toner particles are formed by a polymerization method, the particle size is determined by the concentration of the coagulant, the amount of the organic solvent added, or the fusing time, and the composition of the polymer itself, in the toner manufacturing method described in detail below. Can be controlled by When the number average particle size is 3 to 8 μm, in the fixing step, toner particles having a large adhesive force that fly and adhere to the heating member to generate offset are reduced, and the transfer efficiency is increased, and the halftone The image quality is improved, and the image quality of fine lines, dots, and the like is improved.

In the toner of the present invention, when the particle size of the toner particles is D (μm), the natural logarithm InD is plotted on the horizontal axis, and the horizontal axis is divided into a plurality of classes at intervals of 0.23. In the histogram showing the particle size distribution, the sum (M1) of the relative frequency (m1) of the toner particles included in the most frequent class and the relative frequency (m2) of the toner particles included in the class having the second highest frequency after the most frequent class. ) Is preferably 70% or more.

When the sum (M) of the relative frequency (m1) and the relative frequency (m2) is 70% or more, the dispersion of the particle size distribution of the toner particles becomes narrower. Thus, the occurrence of selective development can be reliably suppressed. In the present invention, the histogram showing the number-based particle size distribution includes a natural logarithm lnD (D: particle size of individual toner particles) in a plurality of classes (0 to 0.23: 0.23 to 0.23) at intervals of 0.23. 0.46: 0.46-0.
69: 0.69-0.92: 0.92-1.15: 1.
15-1.38: 1.38-1.61: 1.61-1.
84: 1.84 to 2.07: 2.07 to 2.30: 2.
30 to 2.53: 2.53 to 2.76...) Is a histogram showing the number-based particle size distribution, which is based on the following conditions. Diameter data is
It is transferred to a computer via the / O unit, and is created by the computer using a particle size distribution analysis program.

[Measurement conditions] (1) Aperture: 100 μm (2) Sample preparation method: electrolytic 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 a dispersion treatment with an ultrasonic disperser for 1 minute.

<< Comparison with Conventionally Known Toner >> In the toner of the present invention, the ratio of toner particles having a shape factor in the range of 1.2 to 1.6 (65% by number or more in toner C) and the variation in shape factor Coefficient (16% or less for toner A and toner C) and the ratio of toner particles having no corners (5% for toner B).
0% or more), and the number variation coefficient in the number particle size distribution (27% or less for toner A and toner B).
It is distinguished from conventionally known and widely used toners.

With respect to the above numerical values of the present invention, numerical values of conventionally widely known toners will be described. This numerical value differs depending on the manufacturing method and further depending on the manufacturing conditions, but will be described in comparison with a typical one.

In the case of the pulverized toner, the shape factor is 1.2 to
The ratio of the 1.6 toner particles is about 60% by number. The variation coefficient of the shape factor is about 20%. Further, in the pulverization method, in order to reduce the particle size while repeating crushing, the toner particles have many corners, and the ratio of toner particles having no corners is 30% by number or less. Therefore,
In order to obtain a rounded toner having no corners and a uniform shape, it is necessary to perform a process of forming a spherical shape by heat or the like as described above as a method of controlling the shape coefficient. In addition, the number variation coefficient in the number particle size distribution is about 30% when the classification operation after the pulverization is performed once, and the classification operation needs to be further repeated to reduce the number variation coefficient to 27% or less. There is.

In the case of the toner obtained by the suspension polymerization method, the toner is conventionally polymerized in a laminar flow, so that substantially spherical toner particles are obtained. For example, in the toner described in JP-A-56-130762, The proportion of toner particles having a coefficient of 1.2 to 1.6 is about 20% by number, the variation coefficient of the shape coefficient is also about 18%, and the proportion of toner particles having no corners is also about 85% by number. Further, as described above as a method for controlling the number variation coefficient in the number particle size distribution, mechanical shearing is repeated for a large oil droplet of a polymerizable monomer to reduce the oil droplet to a size of about a toner particle. Therefore, the distribution of oil droplet diameters is widened, and the particle size distribution of the obtained toner is wide, and the number variation coefficient is as large as about 32%. Therefore, a classification operation is required to reduce the number variation coefficient. .

Polymerized toners formed by associating or fusing resin particles are described, for example, in JP-A-63-163.
In the toner described in Japanese Patent No. 186253, the proportion of toner particles having a shape factor of 1.2 to 1.6 is 60% by number.
The variation coefficient of the shape coefficient is about 18%, and the ratio of toner particles without corners is about 44% by number. Further, the particle size distribution of the toner is wide, and the number variation coefficient is about 30%, and a classification operation is required to reduce the number variation coefficient.

<< Method of Producing Toner >> The toner of the present invention comprises:
The toner is preferably obtained by polymerizing at least a polymerizable monomer in an aqueous medium, and is preferably a toner obtained by associating at least resin particles in an aqueous medium. Hereinafter, the method for producing the toner of the present invention will be described in detail.

The toner of the present invention is obtained by emulsion polymerization of a monomer in a suspension polymerization method or in a liquid (in an aqueous medium) to which an emulsion of necessary additives is added. ) Is prepared, and thereafter, an organic solvent, a flocculant and the like are added thereto to produce the resin particles. Here, “association” means that a plurality of the resin particles are fused together, and also includes a case where the resin particles are fused with other particles (for example, colorant particles).

An example of the method for producing the toner of the present invention is as follows. A colorant and, if necessary, a release agent are contained in a polymerizable monomer.
Various constituent materials such as a charge control agent and a polymerization initiator are added, and the various constituent materials are dissolved or dispersed in the polymerizable monomer using a homogenizer, a sand mill, a sand grinder, an ultrasonic disperser or the like. The polymerizable monomer in which these various constituent materials are dissolved or dispersed is dispersed in an aqueous medium containing a dispersion stabilizer into oil droplets of a desired size as a toner using a homomixer, a homogenizer, or the like. Thereafter, the stirring mechanism is moved to a reaction device (stirring device), which is a stirring blade described later, and heated to cause the polymerization reaction to proceed. After completion of the reaction, the toner of the present invention is prepared by removing the dispersion stabilizer, filtering, washing and drying. In the present invention, “aqueous medium” means that at least 5
It represents one containing 0% by mass or more.

Further, as a method of producing the toner of the present invention, a method of preparing by associating or fusing resin particles in an aqueous medium can also be mentioned. This method is not particularly limited.
No. 5,252, JP-A-6-329947, and JP-A-9-15904. 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, particularly, after dispersing these in water using an emulsifier, the critical aggregation concentration At the same time as adding the above flocculant and salting out, the formed polymer itself is heated and fused at a temperature equal to or higher than the glass transition temperature to gradually form a fused particle, thereby gradually growing the particle size. At this point, a large amount of water was added to stop the growth of the particle diameter, and the surface was smoothened by heating and stirring to control the shape. The toner of the invention can be formed. Here, a solvent that is infinitely soluble in water may be added together with the coagulant.

As the polymerizable monomer constituting the resin, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-chlorostyrene, 3,4- Dichlorostyrene,
p-phenylstyrene, p-ethylstyrene, 2,4-
Dimethylstyrene, p-tert-butylstyrene, p
-N-hexylstyrene, pn-octylstyrene,
pn-nonylstyrene, pn-decylstyrene, p
Styrene or a styrene derivative such as -n-dodecylstyrene, methyl methacrylate, ethyl methacrylate,
N-butyl methacrylate, isopropyl methacrylate,
Methacrylate derivatives such as isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, and 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, phenyl acrylate, etc .; olefins such as ethylene, propylene, isobutylene, vinyl chloride, vinylidene chloride, vinyl bromide , Vinyl fluoride, halogenated vinyls such as vinylidene fluoride, vinyl esters such as vinyl propionate, vinyl acetate, vinyl benzoate, vinyl ethers such as vinyl methyl ether and vinyl ethyl ether, vinyl methyl ketone, vinyl ethyl ketone , Vinyl ketones such as vinylhexyl ketone, N-vinyl compounds such as N-vinylcarbazole, N-vinylindole and N-vinylpyrrolidone, vinyl compounds such as vinylnaphthalene and vinylpyridine, 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 polymerizable monomer constituting the resin in combination with one having an ionic dissociation group. For example, those having a substituent such as a carboxyl group, a sulfonic acid group, and a phosphate group as a constituent group of the monomer, specifically, acrylic acid, methacrylic acid,
Maleic acid, itaconic acid, cinnamic acid, fumaric acid, monoalkyl maleate, monoalkyl itaconate, styrenesulfonic acid, allylsulfosuccinic acid, 2-acrylamido-2-methylpropanesulfonic acid, acid phosphooxyethyl Methacrylate,
3-chloro-2-acid phosphooxypropyl methacrylate and the like.

Further, divinylbenzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate,
Polyfunctional vinyls such as neopentyl glycol diacrylate can be used to form a crosslinked resin.

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 the 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 or diazo 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-based polymerization initiators such as (4,4-t-butylperoxycyclohexyl) propane and tris- (t-butylperoxy) triazine, and polymer initiators having a peroxide in a side chain. . When an 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 acetate, azobiscyanovaleric acid and salts thereof, and hydrogen peroxide.

The dispersion stabilizers include tricalcium phosphate, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, and calcium sulfate. , Barium sulfate,
Bentonite, silica, alumina and the like can be mentioned. Further, a surfactant generally used as a surfactant such as polyvinyl alcohol, gelatin, methyl cellulose, sodium dodecylbenzenesulfonate, ethylene oxide adduct, and higher alcohol sodium sulfate can be used as a dispersion stabilizer.

As the resin excellent in the present invention, a resin having a glass transition point of 20 to 90 ° C. is preferable and a softening point of 8
The thing of 0-220 ° C is preferred. The glass transition point is measured by a differential calorimetric analysis method, and the softening point can be measured by a Koka flow tester. Furthermore, these resins have a number average molecular weight (Mn) of 10 as measured by gel permeation chromatography.
00 to 100000, weight average molecular weight (Mw) 200
Those having 0 to 1,000,000 are preferred. Further, as a molecular weight distribution, Mw / Mn is 1.5 to 100, particularly 1.8.
-70 are preferred.

The flocculant used when associating the resin particles in an aqueous medium is not particularly limited, but those selected from metal salts are preferably used.
Specifically, as a monovalent metal, for example, a salt of an alkali metal such as sodium, potassium, and lithium, and as a divalent metal, for example, a salt of an alkaline earth metal such as calcium and magnesium, or a divalent metal such as manganese or copper And salts of trivalent metals such as iron and aluminum. Specific examples of the salts include sodium chloride, potassium chloride, lithium chloride, calcium chloride, zinc chloride, copper sulfate, magnesium sulfate, and manganese sulfate. Can be mentioned. These may be used in combination. It is preferable that these coagulants are added at a critical coagulation concentration or higher. The critical aggregation concentration is an index relating to the stability of the aqueous dispersion, and indicates the concentration at which aggregation occurs when a coagulant is added. This critical aggregation concentration varies greatly depending on the emulsified component and the dispersant itself. For example, it is described in "Polymer Chemistry 17, 601 (1960), edited by The Society of Polymer Science, Japan" by Seizo Okamura et al., And a detailed critical aggregation concentration can be obtained. As another method, a desired salt is added to the target particle dispersion at a different concentration, the 、 (zeta) potential of the dispersion is measured, and the salt concentration at which this value changes is defined as the critical aggregation concentration. You can also ask. The amount of the coagulant of the present invention may be at least the critical coagulation concentration, but is preferably 1.2 times or more, more preferably 1.5 times or more the critical coagulation concentration.

As the "solvent infinitely soluble in water" used together with the coagulant, a solvent which does not dissolve the resin to be formed is selected. Specific examples include alcohols such as methanol, ethanol, propanol, isopropanol, t-butanol, methoxyethanol and butoxyethanol, nitriles such as acetonitrile, and ethers such as dioxane. Particularly, ethanol, propanol and isopropanol are preferred. The addition amount of the solvent infinitely soluble in water is preferably 1 to 100% by volume based on the polymer-containing dispersion to which the flocculant has been added. In order to make the particle shape uniform, it is preferable to prepare a colored particle, and after the filtration, it is preferable to fluidly dry a slurry in which 10% by mass or more of water is present with respect to the particle. Those having a polar group therein are preferred. It is considered that the reason for this is that the existing water exerts an effect of slightly swelling the polymer in which the polar group is present, so that the shape is particularly easily uniformized.

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

As the colorant used in the toner of the present invention, carbon black, magnetic substance, dye, pigment and the like can be arbitrarily used. As the carbon black, channel black, furnace black, acetylene black, and the like can be used.
Thermal black, lamp black and the like 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 that do not contain ferromagnetic metals but show ferromagnetism by heat treatment, such as manganese-copper-
An alloy of a type called a Heusler alloy such as aluminum, manganese-copper-tin, chromium dioxide, or 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, 79, 81, 82, 93, 98, 10
3, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 60, 70, 93, 9
5 and the like, and a mixture thereof can also be used. Examples of the pigment include C.I. I. Pigment Red 5,
48: 1, 53: 1, 57: 1, 122, 1
39, 144, 149, 166, 177, 1
78, 222, C.I. I. Pigment Orange 31, 43 and C.I. I. Pigment Yellow 14, 17, 17
3, 94, 138, C.I. I. Pigment Green 7, C.I. I. Pigment Blue 15: 3, can be used by the same 60 or the like, can be also used a mixture thereof. The number average primary particle size varies depending on the type, but generally ranges from 10 to
About 200 nm is preferable.

As a method of adding a colorant, a method of adding polymer particles prepared by an emulsion polymerization method at the stage of aggregating by adding an aggregating agent to color the polymer, or a process of polymerizing a monomer can be used. And a method of adding a colorant, polymerizing, and forming colored particles can be used. When the colorant is added at the stage of preparing the polymer, it is preferable to use the colorant after treating the surface with a coupling agent or the like so as not to inhibit the radical polymerizability.

Further, low molecular weight polypropylene (number average molecular weight = 1500 to 9000) or low molecular weight polyethylene as a fixing property improving agent may be added. Similarly, various known charge control agents, which can be dispersed in water, can be used. Specific examples include a nigrosine dye, a metal salt of naphthenic acid or a higher fatty acid, an alkoxylated amine, a quaternary ammonium salt compound, an azo metal complex, a metal salt of salicylic acid, and a metal complex thereof. The particles of the charge control agent and the fixability improver preferably have a number average primary particle diameter of about 10 to 500 nm in a dispersed state.

In the toner of the present invention, more effects can be exhibited by adding and using fine particles such as inorganic fine particles and organic fine particles as external additives. It is presumed that the reason is that the embedding and desorption 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. Further, it is preferable that these inorganic fine particles have been subjected to a hydrophobic treatment with a silane coupling agent, a titanium coupling agent, or the like. The degree of the hydrophobic treatment is not particularly limited,
Those having a methanol wettability of 40 to 95 are preferred. Methanol wettability is to evaluate the wettability to methanol. This method uses distilled water 50 in a 200 ml beaker.
0.2 g of the inorganic fine particles to be measured is weighed and added to each ml. Methanol is slowly dropped from a burette whose tip is immersed in the liquid until the whole of the inorganic fine particles becomes wet while being slowly stirred. 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 equation.

Degree of hydrophobicity = (a / (a + 50)) × 100 The amount of the external additive to be added is 0.1 to 5.
0 mass%, preferably 0.5 to 4.0 mass%. Various external additives may be used in combination.

In a suspension polymerization method toner in which a toner component such as a colorant is dispersed or dissolved in a so-called polymerizable monomer is suspended in an aqueous medium and then polymerized to obtain a toner, a polymerization reaction is performed. By controlling the flow of the medium in the reaction vessel, the shape of the toner particles can be controlled. 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 be present in the aqueous medium in a suspended state. When the oil droplets are gradually polymerized, the oil droplets become soft particles, and when the oil droplets collide, the coalescence of the particles is promoted, and particles with an irregular shape are obtained. . When forming substantially spherical toner particles having a shape factor smaller than 1.2, substantially spherical particles can be obtained by using a medium flow in the reaction vessel as a laminar flow to avoid collision of the particles. In this way,
The distribution of the toner shape can be controlled within the range of the present invention.

<Developer> When the toner of the present invention contains a magnetic material and is used as a one-component magnetic toner, for example,
When used as a two-component developer by mixing with a so-called carrier, there may be cases where a non-magnetic toner is used alone, etc., and any of them can be preferably used. It is preferably used as a two-component developer.

<Developing Method> The developing method in which the toner of the present invention can be used is not particularly limited. An example in which the present invention is applied to a non-contact developing method will be described. In the non-contact developing method, a developer layer formed on a developer carrying member (developer conveying member) does not come into contact with a photoreceptor. In order to constitute this developing method, the developer layer is a thin layer. It is preferable to be formed by. In this method, the development area on the surface of the developer carrier
A developer layer of 0 to 500 μm is formed, and the gap between the photoreceptor and the developer carrier has a larger gap than the developer layer. The thin layer is formed by a magnetic blade using a magnetic force or a method of pressing a developer layer regulating rod against the surface of the developer carrier. Furthermore, there is a method in which a urethane blade, a phosphor bronze plate or the like is brought into contact with the surface of the developer carrier to regulate the developer layer. The pressing force of the pressing regulating member is 10 to 1
50 mN / mm is preferred. When the pressing force is small, the conveyance is likely to be unstable because the regulating force is insufficient. On the other hand, when the pressing force is large, the stress on the developer is increased, and the durability of the developer is likely to be reduced. A preferred range is 30 to 100 mN / mm. The gap between the developer carrier and the surface of the photoconductor needs to be larger than the developer layer. Further, when a developing bias is applied at the time of development, either a method of applying only a DC component or a method of applying an AC bias may be used.

In the present invention, it is preferable to apply an alternating electric field between the developer carrying member (developer conveying member) and the electrostatic latent image holding member (photosensitive member). By applying this alternating electric field, the toner can fly effectively. The condition of this alternating electric field is that the AC frequency f is 200 to
8000 Hz, and an AC voltage Vp-p of 500 to 30
It is preferably 00V. When this alternating electric field is used, it is necessary that the toner has a uniform chargeability. That is, when the chargeability is distributed between the toners, the effect of pulling back the weakly chargeable toner or the like due to the alternating electric field is offset, and as a result, the effect of improving the image quality is reduced.

As the developer carrier used in the present invention, those having a magnet built in the carrier are often used, and the developer is developed by rotating the surface (sleeve) of the developer carrier. It is transported to the area. Aluminum or stainless steel whose surface is oxidized is used as the sleeve. The diameter of the developer carrier is 10 to 10 mm.
40 mm is preferred. When the diameter is small, the mixing of the developer is insufficient, and it is difficult to ensure sufficient mixing to give sufficient charge to the toner. When the diameter is large, the centrifugal force on the developer becomes large. , The problem of toner scattering is likely to occur.

When the toner of the present invention is used in a non-contact developing system, it is preferable to use it as a two-component developer by mixing it with a carrier. As the carrier constituting the two-component developer, magnetic particles made of conventionally known materials such as metals such as iron, ferrite and magnetite, and alloys of these metals with metals such as aluminum and lead can be used. Particularly, ferrite particles are preferable. The magnetic particles have a volume average particle size of 15 to 100 μm,
More preferably, the thickness is 25 to 60 μm. The volume average particle size of the carrier is typically measured by a laser diffraction type particle size distribution analyzer “HELOS (HELO) equipped with a wet disperser.
S) "(manufactured by SYMPATEC). The carrier is preferably a carrier further coated with a resin or a so-called resin-dispersed carrier in which magnetic particles are dispersed in a resin. The resin composition for coating is not particularly limited,
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 constituting the resin dispersion type carrier is not particularly limited, and known resins can be used.
For example, styrene acrylic resin, polyester resin, fluorine resin, phenol resin, and the like can be used.

FIG. 2 is a schematic diagram for explaining an example of the non-contact developing system. Hereinafter, the non-contact developing method will be described with reference to FIG. FIG. 2 is a schematic view of a non-contact developing type developing unit that can be suitably used in the image forming method of the present invention. 10 is a cylindrical photoreceptor, 74 is a developer carrier, 75 is a sleeve, 7
Reference numeral 6 denotes a magnet, 77 denotes a two-component developer containing the toner of the present invention, 78 denotes a developer layer regulating member, 79 denotes a development area, 80 denotes a developer layer, and 81 denotes a power supply for forming an alternating electric field. The two-component developer 77 containing the toner of the present invention is carried by the magnetic force of a developer carrier 74 having a magnet 76 therein, and is conveyed to a development area 79 by movement of a sleeve 75. During this transport, the thickness of the developer layer 80 is regulated by the developer layer regulating member 78 so that the developer layer 80 does not come into contact with the cylindrical photoreceptor 10 in the developing region 79. The minimum gap (Dsd) of the developing area 79 is equal to the thickness (about 50 to 300 μm) of the developer layer 80 conveyed to the area.
m, preferably 100 to 1000 μm (preferably 100 to 500 μm).
m). The power supply 81 is a power supply for forming an alternating electric field, and has a frequency of 200 to 8000 Hz and a voltage of 500.
AC of ~ 3000 Vp-p is preferred. The power supply 81 may have a configuration in which DC is added to AC in series as needed. In that case, the DC voltage is preferably 300 to 800V. Further, when the toner of the present invention is used in the contact type development, the layer thickness of the developer having the toner of the present invention is 0.1 to 8 mm in the development area, particularly 0.4 to 8 mm.
It is preferably about 5 mm. Further, the gap between the photoconductor and the developer carrier is 0.15 to 7 mm, particularly 0.2 to 7 mm.
It is preferably 4 mm.

Although the developing method has been described above by taking the non-contact method as an example, the present invention relates to a contact developing method, that is, a method in which a photosensitive layer is brought into contact with a developer layer formed on a developer carrying member. It goes without saying that the present invention can be applied to a method of forming an image on the top.

<Fixing Method> As a preferable fixing method used in the present invention, a so-called contact heating method can be mentioned. In particular, examples of the contact heating method include a heat and pressure fixing method, a heat roll fixing method, and a pressure contact heat fixing method in which fixing is performed by a rotating pressing member including a fixedly disposed heating element.

In the hot roll fixing method, a heat source is often provided inside a metal cylinder made of iron, aluminum or the like whose surface is coated with tetrafluoroethylene or polytetrafluoroethylene-perfluoroalkoxyvinyl ether copolymer or the like. It is formed of an upper roller and a lower roller made of silicone rubber or the like. A typical example of the heat source is one having a linear heater and heating the surface temperature of the upper roller to about 120 to 200 ° C. In the fixing section, pressure is applied between the upper roller and the lower roller to deform the lower roller and form a so-called nip. The nip width is 1 to 10 mm, preferably 1.
5-7 mm. The fixing linear velocity is 40 mm / sec to 60
0 mm / sec is preferable. When the nip is narrow, heat cannot be uniformly applied to the toner, causing uneven fixing. On the other hand, if the nip width is wide, the melting of the resin is promoted, and a problem occurs in that the fixing offset becomes excessive. A fixing cleaning mechanism may be provided for use. As this method, a method in which a silicone oil is supplied to a roller or a film after fixing, or a method in which a silicone oil-impregnated pad, roller, web or the like is used for cleaning can be used.

Next, a description will be given of a method of fixing by a rotating pressure member including a fixedly disposed heating element used in the present invention. This fixing method is a method in which a heating member fixedly disposed and a pressing member which is opposed to and pressed against the heating member and adheres the recording material to the heating member via a film through a film are used to perform pressure-contact heating and fixing. In this press-contact heat fixing device, the heating element has a smaller heat capacity than a conventional heating roller, and has a linear heating section in a direction perpendicular to the recording material passing direction. 300 ° C. The press-contact heat fixing is a method of fixing an unfixed toner image by pressing the unfixed toner image against a heating source, such as a method of passing a recording material having unfixed toner between a heating member and a pressing member as usually used. is there. By doing so, the heating is performed quickly, so that the fixing speed can be increased. However, it is difficult to control the temperature, and the so-called residual toner is adhered to the unfixed toner directly, such as the surface of the heating source, where the unfixed toner is pressed. There is also a problem that a toner offset is likely to occur, and a failure such as the recording material wrapping around the fixing device is also likely to occur.

In this fixing method, the low-heat-capacity linear heating body fixedly supported by the apparatus has a thickness of 0.2 to 5.0 mm.
0 mm, more preferably 0.5 to 3.5 mm and width 10
A resistance material is applied to an alumina substrate having a length of 240 to 400 mm and a length of 240 to 400 mm, and is supplied with electricity from both ends. Energization is performed at a cycle of 15 to 25 DC100V.
With a pulse waveform of msec, the pulse width is changed according to the temperature / energy release amount controlled by the temperature sensor. In the case of the temperature T1 detected by the temperature sensor in the low heat capacity linear heating element, the surface temperature T2 of the film facing the resistance material is lower than T1. Here, T1 is preferably 120 to 220 ° C., and the temperature of T2 is preferably 0.5 to 10 ° C. lower than the temperature of T1. Further, the film material surface temperature T3 at a portion where the film is separated from the toner surface is substantially equal to T2. The film is moved in the direction of the center arrow in FIG. 3A by contacting the heating body whose energy and temperature are controlled in this manner. Those used as fixing films are heat-resistant films having a thickness of 10 to 35 μm, for example, polyester, polyperfluoroalkoxy vinyl ether, polyimide, and polyetherimide, and in many cases, conductive films such as Teflon (registered trademark). It is an endless film in which a material is added and a release agent layer is covered with 5 to 15 μm.

In driving the film, a driving force and a tension are applied by a driving roller and a driven roller, and the film is conveyed in the direction of the arrow without wrinkles and twists. The linear velocity of the fixing device is preferably 40 to 600 mm / sec. The pressure roller has a rubber elastic layer with high release properties such as silicone rubber,
At a total pressure of 20 to 300 N, it is pressed against the heating element via the film material, and rotates under pressure.

Although an example using an endless film has been described above, it is also possible to use a film sheet sending shaft and a winding shaft as shown in FIG. Good. Further, it may be a simple cylindrical member having no drive roller or the like inside.

The above fixing device may be provided with a cleaning mechanism. As a cleaning method, a method of supplying various silicone oils to the fixing film or a method of cleaning with a pad, a roller, a web or the like impregnated with various silicone oils is used. As the silicone oil, polydimethylsiloxane, polymethylphenylsiloxane, polydiphenylsiloxane and the like can be used. Further, a siloxane containing fluorine can also be suitably used.

Next, FIG. 3 shows an example of a sectional view of the structure of this fixing device. In FIG. 3A, reference numeral 84 denotes a low-heat-capacity linear heating element fixedly supported by the apparatus. As an example, a resistance material 86 is attached to an alumina substrate 85 having a height of 1.0 mm, a width of 10 mm, and a length of 240 mm. Is applied to a width of 1.0 mm, and electricity is supplied from both ends in the longitudinal direction. Energization is performed, for example, at a DC voltage of 100 V, usually in a pulse-like waveform with a period of 20 msec, and is controlled by a signal from the temperature detecting element 87 to maintain a predetermined temperature. For this reason, the pulse width is changed in accordance with the energy release amount, and the range is, for example, 0.5 to 5 msec.

The recording paper (recording material) P carrying the unfixed toner image 93 is brought into contact via the film 88 moved to the heating element 84 controlled in this way, and the toner is thermally fixed.
The film 88 used here moves without generating wrinkles while being tensioned by the driving roller 89 and the driven roller 90. Reference numeral 95 denotes a pressure roller having a rubber elastic layer formed of silicone rubber or the like, and presses the heating body through the film at a total pressure of 40 to 200N. The unfixed toner image 93 on the recording material P is
The fixing image is guided to the fixing unit 6 and a fixed image is obtained by the above-described heating. Although the above description has been made with the endless belt, FIG.
As shown in (b), the film for feeding out the film 91 and the winding shaft 92 may be used, and the fixing film may be an end film.

<Image Forming Apparatus and Process Cartridge>
FIG. 4 is a diagram illustrating a configuration of a digital image forming apparatus (hereinafter, also simply referred to as an image forming apparatus) applied to the present invention.

In the figure, an image forming apparatus 1 includes an automatic document feeder (ADF) A, a document image reading section B for reading an image of a document conveyed by the automatic document feeder, and a read document image. Image control board C to be processed
A writing unit 12 for writing on a cylindrical photoreceptor 10 as an image carrier in accordance with data after image processing
And an image including image forming means such as a cylindrical photoreceptor 10, a charging electrode 14, a developing means 16 composed of a magnetic brush type developing device, a transfer electrode 18, a separation electrode 20, and a cleaning means 21. It has a forming section E and a storage section F for paper feed trays 22 and 24 for storing recording paper P.

The automatic document feeder A is provided with
And a document transport processing unit 28 including a roller group including a roller R1 and switching means for appropriately switching a document movement path (no reference symbol).

The original image reading section B is located below the platen glass G, can move back and forth while maintaining the optical path length, two mirror units 30, 31, a fixed imaging lens (hereinafter simply referred to as a lens) 33, and a line-shaped image forming section. Image sensor (hereinafter referred to as CCD
The writing unit D includes a laser light source 40, a polygon mirror (polarizer) 42, and the like.

When viewed from the direction of movement of the recording paper P as a transfer material, R10 is a registration roller in front of the transfer electrode 18, and H is a fixing unit downstream of the separation electrode 20.

In the embodiment, the fixing means H is composed of a roller having a built-in heating source and a pressure roller which rotates while being pressed against the roller.

Reference numeral Z denotes a cleaning means for the fixing means H, which is mainly composed of a windable cleaning web.

One document (not shown) placed on the document table 26 is transported by the document transport processor 28,
While passing under the roller R1, exposure by the exposure means L is performed.

The reflected light from the original passes through the mirror units 30 and 31 and the lens 33 at the fixed position and passes through the CCD 3
5 and is read.

The image information read by the document image reading section B is processed by the image processing means, encoded, and stored in a memory provided on the image control board C.

Further, the image data is called in accordance with the image formation, and the laser light source 40 in the writing section D is driven according to the image data, so that the cylindrical photosensitive member 10 is exposed.

Prior to the exposure, the cylindrical photoreceptor 10 rotating in the direction of the arrow (counterclockwise) is given a predetermined surface potential by the corona discharge action of the charging electrode 14. The potential decreases according to the exposure amount, and as a result, an electrostatic latent image corresponding to the image data is formed on the cylindrical photoconductor 10.

[0157] The electrostatic latent image is reversely developed by the developing means 16 to be a visible image (toner image).

On the other hand, before the leading end of the toner image on the cylindrical photosensitive member 10 reaches the transfer area, for example,
One of the recording sheets P in 2 is fed and conveyed, reaches the registration roller R10, and is regulated at the leading end.

The recording paper P is conveyed toward a transfer area by a registration roller R10 which starts rotating in synchronization with the toner image, that is, an image area on the cylindrical photoreceptor 10, so as to overlap.

In the transfer area, the toner image on the cylindrical photoreceptor 10 is transferred onto the recording paper P by the urging of the transfer electrode 18, and the recording paper P is then urged by the separation electrode 20. Separated from 10.

Thereafter, the fixing unit H is pressurized and heated to
The toner image is fused and fixed on the recording paper P, and the recording paper P
Is discharged onto a discharge tray T via a discharge path 78 and a discharge roller 79.

The reference symbol Sp on the paper feed tray 24 is
The free end is a movable plate that is constantly urged upward by an urging means such as a coil spring (not shown). As a result, the uppermost sheet comes into contact with a delivery roller described later.

The paper feed tray 22 also has the same configuration as that described above. In the embodiment, the paper feed trays 22 and 24 are arranged in two stages in the vertical direction, but may be provided with more paper feed trays.

[0164] Of the sheet feed trays, the bottom (the same as the bottom wall) of the sheet feed tray 24 arranged at the lower stage (in the embodiment, the sheet feed tray is a two-stage stack, so the lower stage is used, but the lower stage is meant). A space 25 having a predetermined gap is formed between the apparatus and the bottom wall of the apparatus main body.

The space 25 is used in a mode (mode) in which images are formed on both sides of the recording paper P, and is cooperated with a second transport path 80 (described later) for reversing the recording paper P. To achieve the reverse of the front and back.

Reference numerals 50 and 53 above the leading ends (corresponding to the leading ends of the stored recording sheets P as viewed from the sheet feeding direction) of the sheet feeding trays 22 and 24 denote sheet feeding means (hereinafter referred to as feeding Rollers), 51 and 54
Is a feed roller, and 52 and 55 are double feed prevention rollers.

The feed rollers (50, 53) and the feed rollers (51, 54) are formed as a unit, and a drive shaft connected to a drive source provided on the apparatus main body side or a locking means provided on a paper feed unit. It has a configuration that can be easily attached to and detached from.

The double feed prevention rollers (52, 55) are also unitized, and have a structure that can be easily attached to and detached from a fixing member provided at a fixing portion of the apparatus main body.

Reference numeral 60 denotes a manual paper feed tray of the manual paper feed unit, which can be opened and closed with the lower end serving as a fulcrum with respect to the main body side wall of the image forming apparatus 1.

Reference numeral 61 denotes a feed roller which is a roller for feeding the recording paper placed on the manual feed tray 60 with the image formation, 63 denotes a feed roller provided downstream of the feed roller 61, and 65 denotes a feed roller. Roller 6
3, a double feed prevention roller for preventing a plurality of sheets of recording paper P from being fed, and has substantially the same configuration as that of the above-described paper feed trays 22 and 24.

Reference numeral 66 denotes a conveyance path for the recording paper P sent out from the manual feed tray 60, which communicates with a later-described junction through a pair of conveyance rollers immediately to the left of the feed roller 63.

Reference numeral 70 denotes a first conveyance path for forming an image on the recording paper P by transfer, and extends upward from below when viewed from the moving direction of the recording paper sent from an appropriate paper feed tray. .

Reference numeral 72 denotes a paper feeding passage for recording paper stored in the upper paper feeding tray 22, reference numeral 74 denotes a paper feeding passage for recording paper stored in the lower paper feeding tray 24, and reference numeral 76 denotes both trays 2.
It is a merging portion (a part of the first conveyance path 70) where the recording papers P sent from 2 and 24 merge.

Reference numeral 78 denotes a paper discharge path for discharging the recording paper on which a predetermined image has been formed onto the paper discharge tray T.

Reference numeral 80 denotes a second conveyance path for reversing the recording paper used for forming an image on both sides of the recording paper.
The upper part of the figure communicates with the first transport path.

The second transport path 80 extends downward from above when viewed from the direction of movement of the recording paper.

The lower end of the second conveying path 80 is a conveying path extending substantially vertically, and the lower end thereof extends below the sheet feeding section of the lower sheet feeding tray 24.
0 (connected).

As understood from the above, the first transport path 7
0 and the second transport path 80 form a long loop in the longitudinal direction on one side wall side of the apparatus main body.

At the connection between the first transport path 70 and the second transport path 80, a transport means R20 (also serving as a switchback roller) comprising a pair of reversible rollers is provided.

Since the recording paper P is not continuously transported from the second transport path 80 to the first transport path 70, the connection section can be said to be a branch section that separates both transport paths.

A path leading to the space 25 is provided below the switchback roller R20, and when the recording paper P is turned upside down, the recording paper P moving through the second transport path 80 is passed through the space 25. Used to go to.

In the image forming process, the second transport path 8
When the recording paper P moving through the recording paper P is sent out toward the space 25, the rear end of the recording paper P is configured to be gripped by the switchback roller R20. 25 stores a part of the recording paper.

Reference numeral 90 denotes an (upper) branch guide which directs the recording paper P, on which an image has been formed on the first surface, to the paper discharge path 78,
Alternatively, it is controlled so as to be directed to the second transport path 80.

In other words, the image forming apparatus is controlled according to a user-set image forming mode (a mode in which an image is formed on only one side of a recording sheet or a mode in which an image is formed on both sides of a recording sheet).
It can be said that the recording paper transport path is switched.

When an image is formed in the image forming section E configured as described above, first, the surface of the cylindrical photosensitive member 10 is charged by the discharging action of the charging electrode 14 as the cylindrical photosensitive member 10 rotates. Next, an image is written in the writing section D to form an electrostatic latent image. The electrostatic latent image is developed by the developing means 16 to form a toner image. On the other hand, the paper feed trays 22, 2
4 or the recording paper P fed from the manual paper feed tray 60, the toner image is transferred by the transfer electrode 18, the recording paper P is separated by the separation electrode 20, fixed by the fixing unit H, and fixed on the discharge tray T. Is discharged to

FIG. 5 is a sectional view of the cleaning means used in the image forming apparatus of the present invention.

In FIG. 5, the cylindrical photoreceptor 10 is installed in the image forming apparatus such that the central axis of the cylinder is substantially horizontal. The term “substantially horizontal” refers to a horizontality at which the angle at which the central axis of the cylinder intersects the horizontal plane is within ± 10 degrees. A cleaning unit 21 is provided above the cylindrical photoconductor 10. As shown in the figure, the cleaning blade 211 is disposed above a line HL passing through the rotation center 10A of the cylindrical photoreceptor 10, and a position perpendicular to the central axis of the cylindrical photoreceptor 10 is set to 0 degree. When the central angle (β) is within ± 30 degrees, the tip of the cleaning blade 211 is pressed against the surface of the photoconductor to clean the toner on the photoconductor.

On the side of the frame 218 of the cleaning means 21, a sheet-like conductive member 219 and a separation claw 217 are provided on the upstream side of the cleaning blade. Both the sheet-like conductive member 219 and the separation claw 217 are cylindrical. Photoreceptor 10
Touching the surface.

Further, a support 212 is rotatably supported by a shaft 213 in the frame 218, and the base of the cleaning blade 211 is fixed to one end of the support 212. The other end 222 of the support 212 is provided so as to be exposed outside from the frame 218.

In the operating state of the cleaning means 21, the tip of the cleaning blade 211 is pressed against the cylindrical photoreceptor 10 by the elastic force of the spring S provided at the other end of the support 212. On the rear end side of the cleaning blade 211, and
An elastic plate 214 is provided at one end of the support 212 so as to be located downstream of the shaft 213 with respect to the rotation direction of the cylindrical photoconductor 10, and one end thereof is fixed. Works to prevent. Elastic plate 21
4 is preferably made of an elastic plate such as polyurethane rubber or polyethylene terephthalate.

After the toner image is transferred onto the recording paper P in the frame 218, when the residual toner on the cylindrical photoreceptor 10 is cleaned by the cleaning blade 211, the frame 2
The toner discharge members 215 and 216 for sequentially discharging the residual toner to the outside from inside 18 are provided.

FIG. 6 is a diagram illustrating in more detail the setting of the cleaning blade, sheet-like conductive member and cylindrical organic photoreceptor of the present invention.

In FIG. 6, the cleaning blade 211
Is 0 degrees above the central axis of the cylindrical photoconductor 10, the photoconductor cylinder center angle (β) is within ± 30 degrees,
It is in pressure contact with the photoconductor surface (contact point A).

In the present invention, the cleaning blade 21
Preferred values of the contact load P and the contact angle θ on the photoconductor 1 are P = 5 to 40 N / m and θ = 5 to 35 °.

Further, as shown in FIG. 3, the cleaning blade free length L represents the length from the end of the support 212 to the tip of the blade before deformation. A preferred value of the free length is L = 5 to 15 mm. The thickness of the cleaning blade is preferably 0.5 to 4 mm.

The contact load P is the cleaning blade 211
Is the vector value in the normal direction of the pressing force P ′ when the abutment is brought into contact with the cylindrical photoconductor 10.

The contact angle θ is the tangent X at the contact point A of the photosensitive member and the blade before deformation (shown by a two-dot chain line in the drawing).
And the angle formed by

As the material of the elastic rubber blade used for the cleaning blade, urethane rubber, silicone rubber, fluorine rubber, chloropyrene rubber, butadiene rubber and the like are known. Of these, urethane rubber is other rubber. It is particularly preferred in that it has excellent wear characteristics as compared with For example, urethane rubber obtained by reacting and curing a polycaprolactone ester and a polyisocyanate described in JP-A-59-30574 is preferable.

The sheet-shaped conductive member 219 is provided on the side of the frame 218 of the cleaning means 21 and on the upstream side of the cleaning blade (in the rotation direction of the photosensitive member). Is in contact with the photoreceptor surface. As a result, the charge on the toner and the photoreceptor is removed, and as a result, the cleaning property is improved, and an excessive load is not applied to the cleaning blade, and the blade failure such as turning over of the blade and squealing of the blade is prevented.

In FIG. 6, reference numeral 220 denotes a backing member (a folded polyethylene terephthalate sheet or the like) of a sheet-shaped conductive member. Reference numeral 221 denotes a toner guide (a sheet such as a polyethylene terephthalate sheet). Prevents scattering to the outside. Further, in order to effectively remove the charge of the toner or the photoconductor, it is preferable that the sheet-shaped conductive member 219 is grounded (grounded).

In the present invention, the cleaning blade contact width (the width in the direction parallel to the axis of the cylindrical photosensitive member) is preferably set to be longer than the photosensitive layer width of the organic photosensitive member. If the cleaning blade contact width is set shorter than the width of the photosensitive layer, toner is likely to slip through on both sides of the cylindrical photoconductor, and cleaning failure is likely to occur.

The cleaning blade used in the present invention is preferably an elastic rubber blade. The physical properties of the cleaning blade can be controlled to be small by controlling the rubber hardness and the rebound resilience at the same time. Can be suppressed. Blade J at 25 ± 5 ° C
When the ISA hardness is less than 65, reversal of the blade is likely to occur, and when it is more than 80, the cleaning performance decreases. When the rebound resilience exceeds 80, reversal of the blade tends to occur, and when the rebound resilience is 20 or less, the cleaning performance deteriorates. More preferable rebound resilience is 20 or more and 80.
It is as follows. The Young's modulus is preferably in the range of 294 to 588 N / cm ² . (Both the JISA hardness and the rebound resilience are measured based on the vulcanized rubber physical test method of JIS K6301. The value of the rebound resilience indicates%.) As the material of the elastic rubber blade used for the cleaning blade, urethane rubber, silicone rubber, Fluorine rubber, chloropyrene rubber, butadiene rubber, and the like are known, and among these, urethane rubber is particularly preferable because it has excellent wear characteristics as compared with other rubbers. For example,
Urethane rubbers obtained by reacting and curing polycaprolactone esters and polyisocyanates described in JP-A-59-30574 are preferred.

In the image forming method having the above-described cleaning means, the toner scraped off by the cleaning blade is difficult to separate from the surface of the photoreceptor, and cleaning failure often occurs. In particular, when the above-described cleaning means is employed in an image forming apparatus using a polymerized toner and an organic photoreceptor, poor cleaning tends to occur.

The present invention relates to an image forming method having the above-mentioned cleaning means, wherein the ratio of the width of the photosensitive layer of the organic photosensitive member to the length of the cylindrical conductive support is 80/100 to 99 /.
It is characterized by being 100.

[0205]

EXAMPLES The present invention will be described below in detail with reference to examples, but embodiments of the present invention are not limited thereto.

[A] Photoreceptor Preparation of Photoreceptor P1 The following coating solutions were sequentially applied to an aluminum drum support having a length of 380 mm and a diameter of 60 mm to prepare a photoreceptor P1.

<< Intermediate Layer >> Organometallic compound: Titanium chelate compound “TC-750” (manufactured by Matsumoto Pharmaceutical Co., Ltd.) 300 g Silane coupling agent “KBM-503” (manufactured by Shin-Etsu Chemical Co., Ltd.) 170 g 2-propanol 1500 ml To form a film having a film thickness of 0.1 on a cylindrical conductive support.
It was applied to a thickness of 5 μm.

<< CGL >> Y-type titanyl phthalocyanine (Titanyl phthalocyanine having a maximum peak at 27.2 degrees at a Bragg angle of 2θ (± 0.2) in Cu-Kα characteristic X-ray diffraction spectrum measurement) 600 g Silicone-modified butyral resin (X-40-1211M: manufactured by Shin-Etsu Chemical Co., Ltd.) 7000 g 2-butanone 20,000 ml was mixed and dispersed using a sand mill for 10 hours to prepare a charge generation layer coating solution. This coating solution was applied on the intermediate layer by a dip coating method to form a 0.2 μm-thick charge generation layer.

<< CTL >> Charge transport substance (N- (4-methylphenyl) -N- {4- (β-phenylstyryl) phenyl} -p-toluidine) 225 g Polycarbonate (viscosity average molecular weight 30,000) 300 g Antioxidant Agent (Exemplified Compound 1-3) 6 g Dichloromethane 2000 ml was mixed and dissolved to prepare a charge transport layer coating solution. This coating solution was applied on the charge generation layer by a dip coating method to form a charge transport layer having a dry film thickness of 20 μm.

Preparation of Photoconductor P2 A photoconductor P2 was prepared in the same manner as P1, except that the intermediate layer of the photoconductor P1 was replaced with the following materials.

<< Intermediate Layer >> Organic metal compound; zirconium chelate compound “ZC-540” (manufactured by Matsumoto Pharmaceutical Co., Ltd.) 200 g Silane coupling agent “KBM-903” (manufactured by Shin-Etsu Chemical Co., Ltd.) 100 g methanol 700 ml ethanol 300 ml Coated on aluminum support, 150
It dried at 30 degreeC and 30 minutes, and formed the 0.5-micrometer-thick intermediate | middle layer.

Preparation of Photoreceptor P3 A photoreceptor P3 was prepared in the same manner as P1 except that the intermediate layer of the photoreceptor P1 was changed to the following material.

Silane Coupling Agent “KBM-903” (manufactured by Shin-Etsu Chemical Co., Ltd.) 300 g Water 30 ml Ethanol 1000 ml Preparation of Photoconductor P4 Photosensitizer P4 was prepared in the same manner as P1 except that the intermediate layer of photoconductor P1 was changed to the following material. A photoreceptor of body P4 was made.

Organometallic compound: Titanium chelate compound “TC-100” (manufactured by Matsumoto Pharmaceutical Co., Ltd.) 200 g Silane coupling agent “KBM-903” (manufactured by Shin-Etsu Chemical Co., Ltd.) 130 g Toluene 1000 ml Water 30 ml Preparation of photoconductor P5 (Comparative Example) Photoconductor A photoconductor P5 was prepared in the same manner as P1 except that the intermediate layer of the photoconductor P1 was replaced with the following material.

Polyamide resin “CM-8000” (manufactured by Toray Industries, Inc.) 150 g 2-propanol 1500 ml methanol 8500 ml [B] Toner Production of toner T1: Example of emulsion polymerization association method 0.90 kg of sodium n-dodecyl sulfate and pure water 10.2.
0 liter was added and dissolved by stirring. To this solution was added Regal 330R (carbon black manufactured by Cabot Corporation) 1.20.
kg was gradually added, and the mixture was stirred well for 1 hour, and then continuously dispersed for 20 hours using a sand grinder (medium type disperser). This is referred to as “colorant dispersion liquid 1”. Also,
Sodium dodecylbenzenesulfonate 0.055kg
And a solution composed of 4.0 liters of ion-exchanged water is referred to as “anionic surfactant solution A”. A solution consisting of 0.014 kg of nonylphenol polyethylene oxide adduct of 10 mol and 4.0 liters of ion-exchanged water is referred to as “nonionic surfactant solution B”. Potassium persulfate 223.8
g in 12.0 liters of ion-exchanged water is referred to as "initiator solution C".

A WAX emulsion (polypropylene emulsion having a number average molecular weight of 3000: number average primary particle diameter = 12) was placed in a 100-liter GL (glass lining) reactor equipped with a temperature sensor, a cooling pipe, and a nitrogen introducing device.
(0 nm / solid content concentration = 29.9%), 3.41 kg, the entire amount of “anionic surfactant solution A” and the entire amount of “nonionic surfactant solution B” were added, and stirring was started. Next, 44.0 liters of ion-exchanged water was added.

The heating was started, and when 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., the styrene 1
2.1 kg, 2.88 kg of n-butyl acrylate, 1.04 kg of methacrylic acid, and t-dodecyl mercaptan 54
8 g were added dropwise. After the completion of the dropwise addition, the temperature of the solution was raised to 80 ° C. ± 1 ° C., and the mixture was heated and stirred for 6 hours. Subsequently, the liquid temperature was cooled to 40 ° C. or lower, stirring was stopped, and the mixture was filtered with a pole filter to obtain a latex. This is designated as "latex-A". The glass transition temperature of the resin particles in Latex-A was 57 ° C., the softening point was 121 ° C., the molecular weight distribution was mass average molecular weight = 1270,000, and the weight average particle size was 120 nm.

A solution obtained by dissolving 0.055 kg of sodium dodecylbenzenesulfonate in 4.0 liters of ion-exchanged pure water is referred to as “anionic surfactant solution D”. A solution obtained by dissolving 0.014 kg of a 10 mol adduct of nonylphenol polyethylene oxide in 4.0 liters of ion-exchanged water is referred to as “nonionic surfactant solution E”.
A solution obtained by dissolving 200.7 g of potassium persulfate (manufactured by Kanto Chemical Co., Ltd.) in 12.0 liters of ion-exchanged water is referred to as “initiator solution F”.

A 100-liter GL reactor equipped with a temperature sensor, a cooling pipe, a nitrogen introducing device, and a comb-shaped baffle was charged with W.
3.41 kg of AX emulsion (polypropylene emulsion having a number average molecular weight of 3000: number average primary particle diameter = 120 nm / solid content concentration of 29.9%), the total amount of “anionic surfactant solution D” and the total amount of “nonionic surfactant solution E” And stirring was started. Next, ion-exchanged water 4
4.0 liters were charged. Start heating and liquid temperature is 7
When the temperature reached 0 ° C., “Initiator solution F” was added.

Then, 11.0 kg of styrene, 4.00 kg of n-butyl acrylate and 1.04 kg of methacrylic acid were used.
And a solution in which 9.02 g of t-dodecylmercaptan was previously mixed was added dropwise. After completion of dropping, the liquid temperature is set to 72 ° C.
The mixture was heated and stirred for 6 hours while controlling to ± 2 ° C. further,
The liquid temperature was raised to 80 ° C. ± 2 ° C., and the mixture was heated and stirred for 12 hours. The liquid temperature was cooled to 40 ° C. or less, and the stirring was stopped. The solution was filtered through a Pall filter, and the filtrate was used as “latex-
B ". In addition, the glass transition temperature of the resin particles in the latex-B is 58 ° C, the softening point is 132 ° C, and the molecular weight distribution is as follows: weight average molecular weight = 245,000, and weight average particle size is 11
It was 0 nm.

Sodium chloride as salting-out agent 5.36k
g in 20.0 liters of ion-exchanged water is referred to as "sodium chloride solution G". A solution obtained by dissolving 1.00 g of a fluorine-based nonionic surfactant in 1.00 liter of ion-exchanged water is referred to as “nonionic surfactant solution H”.

A 100-liter SUS reaction vessel equipped with a temperature sensor, a cooling pipe, a nitrogen introduction device, and a particle size and shape monitoring device (reactor having a two-stage stirring blade, crossing angle α of blades of 25 °). The latex-A prepared above
= 20.0 kg, latex-B = 5.2 kg, colorant dispersion 1 = 0.4 kg, and 20.0 kg of ion-exchanged water and stirred. Then, the mixture was heated to 40 ° C., and sodium chloride solution G and isopropanol (manufactured by Kanto Chemical Co.) 6.00.
kg and Nonionic surfactant solution H were added in this order.
Then, after standing for 10 minutes, the temperature was started to rise to a liquid temperature of 85 ° C. in 60 minutes, and 0.5 to 3 at 85 ± 2 ° C.
The particle size was grown while heating and stirring for salting out / fusion. Next, 2.1 liters of pure water was added to stop the particle size growth.

In a 5-liter reaction vessel equipped with a temperature sensor, a cooling pipe, and a monitoring device for particle size and shape (a reaction device having a two-stage stirring blade, the crossing angle α of the blade was 20 °),
5.0 kg of the above-prepared fused particle dispersion was added, and heated and stirred at a liquid temperature of 85 ° C. ± 2 ° C. for 0.5 to 15 hours to control the shape. Thereafter, the mixture was cooled to 40 ° C. or lower and the stirring was stopped.

Next, classification was performed in the liquid by a centrifugal sedimentation method using a centrifugal separator, followed by filtration through a sieve having openings of 45 μm, and the filtrate was used as an associated liquid. Next, non-spherical particles in the form of a wet cake were collected by filtration from the associated liquid using a Nutsche. Thereafter, the substrate was washed with ion-exchanged water. The non-spherical particles were dried at a suction air temperature of 60 ° C. using a flash jet drier, and then dried at a temperature of 60 ° C. using a fluidized bed drier. 100 of the obtained colored particles
1 part by mass of silica fine particles was externally added to the parts by mass with a Henschel mixer and mixed to obtain a toner by an emulsion polymerization association method.
In the monitoring of the salting-out / fusion step and the shape control step, the number of rotations of the stirring and the heating time are controlled to control the variation coefficient of the shape and the shape coefficient. Was adjusted to obtain toners T1-1 to T11 composed of toner particles having the shape characteristics and the particle size distribution characteristics shown in Table 1.

Production of Toner T2: Example of Suspension Polymerization Method Styrene = 165 g, n-butyl acrylate = 35
g, carbon black = 10 g, metal di-t-butylsalicylate = 2 g, styrene-methacrylic acid copolymer = 8 g, paraffin wax (mp = 70 ° C.) = 20
g was heated to 60 ° C., and was uniformly dissolved and dispersed at 12,000 rpm with a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.).
To this, 2,2'-azobis (2,4-
(Valeronitrile) = 10 g was added and dissolved to prepare a polymerizable monomer composition.

Then, 450 g of a 0.1 mol / L aqueous sodium phosphate solution was added to 710 g of ion-exchanged water, and 68 g of 1.0 mol / L calcium chloride was gradually added while stirring at 13000 rpm with a TK homomixer. Was prepared. The polymerizable monomer composition was added to the suspension, and the mixture was stirred with a TK homomixer at 10,000 rpm for 20 minutes to granulate the polymerizable monomer composition. Then, using a reactor having a two-stage stirring blade configuration (intersection angle α is 45 °),
The reaction was performed for 15 hours. Tricalcium phosphate was dissolved and removed with hydrochloric acid, and then classified in a liquid by a centrifugal sedimentation method using a centrifugal separator, followed by filtration, washing and drying.

To 100 parts by mass of the obtained colored particles, 1 part by mass of silica fine particles was externally added and mixed with a Henschel mixer to obtain a toner by a suspension polymerization method.

By monitoring during the polymerization and controlling the liquid temperature, the number of rotations of stirring, and the heating time, the variation coefficient of the shape and the shape coefficient are controlled. The coefficients were arbitrarily adjusted to obtain toners T2-1 to T3-1 comprising toner particles having the shape characteristics and the particle size distribution characteristics shown in Table 1.

Production of Toner T3: Example of Suspension Polymerization Method In the production example of toner T2, a reactor having a two-stage stirring blade configuration (intersection angle α was 15 °) and a centrifugal separator were used. A toner T3-1 consisting of toner particles having the shape characteristics and particle size distribution characteristics shown in Table 1 was obtained in the same manner except that classification in the liquid was not performed.

Production of Toner T4: Example of Pulverization Method Styrene-n-butyl acrylate copolymer resin 100 k
g, 10 kg of carbon black and 4 parts by mass of polypropylene are preliminarily mixed by a Henschel mixer, melt-kneaded by a twin-screw extruder, coarsely ground by a hammer mill, and ground by a jet mill, The obtained powder is dispersed in a hot air stream of a spray dryer (20
Particles whose shape was adjusted (at 0 to 300 ° C. for 0.05 seconds) were obtained. These particles were repeatedly classified by an air classifier until the target particle size distribution was obtained. To 100 parts by mass of the obtained colored particles, 1 part by mass of silica fine particles was externally added and mixed with a Henschel mixer to obtain a toner by a pulverization method. In this way,
Toners T4-1 to T3-1 comprising toner particles having the shape characteristics and the particle size distribution characteristics shown in Table 1 were obtained by controlling the shape and the coefficient of variation of the shape coefficient, and further adjusting the coefficient of variation of the particle size and the particle size distribution.

[0231]

[Table 1]

[Manufacture of developer] Toners T1-1 to T4-
Each of No. 3 and a 45 μm ferrite carrier coated with a styrene-methacrylate copolymer were mixed with 200 g of the carrier for 20 g of the toner to prepare a developer for evaluation.

[Evaluation] As shown in Table 2, a combination of a photoreceptor and a developer was set, and a digital copying machine (corona charging, laser exposure, reversal development, basically) having the image forming process shown in FIG. , Electrostatic transfer, nail separation, and cleaning blade).

However, in order to allow the photosensitive member and the cleaning blade to blend in before the start of the evaluation, setting powder (polyvinylidene fluoride powder) was sprayed on the photosensitive member and the cleaning blade, and the photosensitive member was rotated for one minute.

The copying conditions were as follows: 200,000 continuous copies were made in a high-temperature and high-humidity environment (30 ° C., 80% RH), which is considered to be the most severe, and the fog unevenness, sharpness, and black spots of the copied images were evaluated according to the following evaluation criteria. Was done. Black spots were evaluated when the thickness of the photosensitive layer became about 15 μm.

The evaluation was performed by copying an original image having a character rate of 7%, a portrait image of a person, a solid white image, and a solid black image, each of which is equal to 1/4, on A4 neutral paper and performing solid white printing. Image, solid black image, fine line image, image (black spot defect:
(Black pot) was evaluated.

Regarding the fog unevenness, the absolute reflection density of each image was measured using RD-918 manufactured by Macbeth.

For the fine line image, the sharpness was determined by visually checking the number of fine lines per 1 mm which can be determined from the copy image of the fifth generation.

The black spots were evaluated by measuring the particle size and the number of black spots using an image analyzer “Omnicon 3000” (manufactured by Shimadzu Corporation).
It was judged by whether m ² there is nothing per.

Regarding the cleaning property, 10 sheets of the original image having a ratio of solid black image 4: solid white image 1 of A3 paper were continuously copied 10 times, and it was determined whether or not cleaning failure occurred in the solid white portion.

Fog unevenness: Judgment based on solid white image density A: 0.005 or less (good) O: Greater than 0.005 and less than 0.01 (level that causes no practical problem) ×: 0.01 or more (a practical problem occurs) ) Sharpness: judged by fine line image 画像: 8 lines / mm or more (good) ○: 5.6 lines / mm or more, 7.1 lines / mm or less (a level that does not cause any practical problem) ×: 5 lines / mm or less ( Cleaning performance: Judgment based on the occurrence of poor cleaning in solid white areas ◎: No toner slippage occurs on 200,000 sheets ○: No toner slippage occurs up to 100,000 sheets ×: Less than 100,000 sheets Occurrence of toner slippage Black spots ：: 1 black spot of 0.1 mm or more / 100 cm ² or less: good ：: 2-3 black spots of 0.1 mm or more / 100c
m ² : Level having no practical problem ×: 4 black dots of 0.1 mm or more / 100 cm ² or more: There is a practical problem Other evaluation conditions Other evaluation conditions of the above digital copying machine were set as follows.

Charging Conditions Charger: Scorotron charger, initial charging potential was -750
Adjusted to V.

Exposure conditions The exposure amount was set so that the exposure portion potential was -50V.

Developing conditions DC bias: -550 V was set.

Transfer pole: Corona charging was adopted. Table 2 shows the evaluation results.

[0246]

[Table 2]

As is clear from Table 2, in the examples satisfying the conditions of the present invention, image characteristics such as black spots, fog unevenness, sharpness, uniformity, and cleaning properties are clearly improved.

[0248]

According to the present invention, toners having specific particle shapes or particle distributions represented by the following toners A, B and C have high offset and fixing properties, and are excellent in developability and sharpness. Without impairing the problem, namely, black spots, fog spots, cleaning properties,
It is possible to provide a method, an image forming apparatus, and a process cartridge, which have a method for improving the adhesiveness and the like and have stable high image quality even in long-term use.

Toner A: The coefficient of variation of the shape factor is 16% or less, and the coefficient of variation of number in the particle size distribution is 27%.
A toner composed of the following toner particles.

Toner B: The ratio of toner particles having no corners is 5
A toner composed of toner particles having 0% by number or more and a number variation coefficient in a number particle size distribution of 27% or less.

Toner C: A toner composed of toner particles having a shape coefficient in the range of 1.2 to 1.6 in which the proportion of toner particles is 65% by number or more and the coefficient of variation of the shape coefficient is 16% or less. .

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a toner particle having no corner and a toner particle having a corner.

FIG. 2 is a schematic diagram illustrating an example of a non-contact developing method.

FIG. 3 is a diagram illustrating an example of a fixing method to which the present invention is applied.

FIG. 4 is a configuration diagram of a digital image forming apparatus applied to the present invention.

FIG. 5 is a sectional view of a cleaning unit used in the image forming apparatus of the present invention.

FIG. 6 is a diagram illustrating settings of a cleaning blade, a sheet-shaped conductive member, and a cylindrical organic photoconductor of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image forming apparatus 10 Cylindrical photoreceptor 14 Charging electrode 16 Developing means 18 Transfer electrode 20 Separation electrode 22, 24, 60 Paper feed tray 40 Laser light source A Automatic document feeder (commonly called ADF) B Document image reading section C Image control board D Writing section P Recording paper (recording material) R10 Registration roller

Continued on the front page (72) Inventor Ken Omura 2970, Ishikawacho, Hachioji-shi, Tokyo Konica Corporation (72) Inventor Mao 2970, Ishikawacho, Hachioji-shi, Tokyo Konica Corporation F-term (reference) 2H005 AB06 EA05 EA10 2H068 AA16 AA21 AA42 BA12 BA16 BA57 BA58 FA27

Claims (28)

[Claims] 1. An electrostatic latent image formed on an electrophotographic photosensitive member having a photosensitive layer on a conductive support via an intermediate layer,
In an image forming method including a developing step of visualizing with an electrostatic image developing toner containing at least a resin and a colorant, the intermediate layer of the photoreceptor contains at least one of an organometallic compound and a silane coupling agent. An image forming method, wherein a toner having a shape coefficient variation coefficient of 16% or less and a number variation coefficient in a number particle size distribution of 27% or less is used as the toner. 2. The image forming method according to claim 1, wherein the organic metal compound contained in the intermediate layer is a metal alkoxide or an organic metal chelate. 3. The image forming method according to claim 1, wherein the intermediate layer is a layer containing an organic metal chelate and a silane coupling agent. 4. The image forming method according to claim 1, wherein the organometallic chelate contained in the intermediate layer is represented by the following general formula (1). General formula (1) (R ₁ O) _g -M- (K) _m (wherein R ₁ is an alkyl group, M is zirconium,
Represents titanium or aluminum. K represents an acetoacetate group or a β-diketone residue. g and m represent an integer of 1 or more. However, when M is zirconium or titanium, g + m is 4, and when M is aluminum, g + m is 3. ) 5. The image forming method according to claim 1, wherein the silane coupling agent contained in the intermediate layer is represented by the following general formula (2). Formula (2) (Q) _p- Si (Y) _q- (A) _r (wherein Q represents a halogen atom, an alkoxy group or an amino group, A represents an alkyl group or an aryl group, and Y represents- BOOC (R ') C = CH 2, -BNHR " or -B
Represents NH ₂ . R 'represents an alkyl group, R "represents an alkyl group or an aryl group, B represents an alkylene group or an alkylene group containing -O-, -NH-, -CO-, and p and q are integers of 1 or more. And r represents an integer of 0 or more, and p + q + r is 4.) 6. The image forming method according to claim 1, wherein the photosensitive layer contains a hindered amine or a hindered phenol compound. 7. A toner having a shape factor of 1.0 to 1.6.
The image forming method according to any one of claims 1 to 6, wherein the ratio of the toner particles falling within the range is 65% by number or more. 8. The toner according to claim 1, wherein said toner has a shape factor of 1.2 to 1.6.
The image forming method according to any one of claims 1 to 6, wherein the ratio of the toner particles falling within the range is 65% by number or more. 9. The toner according to claim 1, wherein the ratio of the cornerless toner particles of the toner is 50% by number or more.
The image forming method according to claim 1. 10. The toner particles having a number average particle size of 3 to 3.
10. The method according to claim 1, wherein the thickness is 8 μm.
Item. 11. 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 shows the number-based particle size distribution divided into a plurality of classes at intervals of 0.23. In the histogram, the sum (M) of the relative frequency (m1) of the toner particles included in the most frequent class and the relative frequency (m2) of the toner particles included in the next most frequent class after the most frequent class is 70%. The image forming method according to claim 1, wherein: 12. The image forming method according to claim 1, wherein the toner is obtained by polymerizing at least a polymerizable monomer in an aqueous medium. 13. The image forming method according to claim 1, wherein at least resin particles of the toner are obtained by being associated in an aqueous medium. 14. An electrostatic latent image formed on an electrophotographic photosensitive member having a photosensitive layer on a conductive support via an intermediate layer for developing an electrostatic image containing at least a resin and a colorant. In an image forming method including a developing step of visualizing with a toner, the intermediate layer is a layer containing at least one of an organometallic compound and a silane coupling agent, and the toner has a ratio of toner particles having no corners. An image forming method, comprising using a toner having a number of 50% or more and a number variation coefficient of 27% or less in a number particle size distribution. 15. The toner according to claim 1, wherein said toner has a shape factor of 1.0 to 1.
The image forming method according to claim 14, wherein the ratio of the toner particles in the range of 6 is 65% by number or more. 16. The toner according to claim 1, wherein said toner has a shape factor of 1.2 to 1.
The image forming method according to claim 14, wherein the ratio of the toner particles in the range of 6 is 65% by number or more. 17. The toner according to claim 17, wherein the number average particle diameter of the toner particles is 3 to 3.
The image forming method according to claim 14, wherein the thickness is 8 μm. 18. When the particle size of the toner particles is D (μm), the natural logarithm InD is plotted on the horizontal axis, and the horizontal axis shows the number-based particle size distribution divided into a plurality of classes at intervals of 0.23. In the histogram, the sum (M) of the relative frequency (m1) of the toner particles included in the most frequent class and the relative frequency (m2) of the toner particles included in the next most frequent class after the most frequent class is 70%. The image forming method according to any one of claims 14 to 17, wherein: 19. The image forming method according to claim 14, wherein the toner is obtained by polymerizing at least a polymerizable monomer in an aqueous medium. 20. The image forming method according to claim 14, wherein the toner is obtained by associating at least resin particles in an aqueous medium. 21. An electrostatic latent image formed on an electrophotographic photosensitive member having a photosensitive layer on a conductive support via an intermediate layer for developing an electrostatic image containing at least a resin and a colorant. In an image forming method including a development step of developing with a toner, the intermediate layer is a layer containing at least one of an organometallic compound and a silane coupling agent, and the toner has a shape factor of 1.2 to 1. 6, the ratio of the toner particles is 65% by number or more, and the variation coefficient of the shape coefficient is 1
An image forming method using a toner of 6% or less. 22. The method according to claim 21, wherein a ratio of the toner particles having no toner corner is 50% by number or more.
2. The image forming method according to 1., 23. The number average particle diameter of the toner particles is 3 to
The image forming method according to claim 21, wherein the thickness is 8 μm. 24. When the particle size of the toner particles is D (μm), the natural logarithm lnD is plotted on the horizontal axis, and the horizontal axis shows the number-based particle size distribution divided into a plurality of classes at 0.23 intervals. In the histogram, the sum (M) of the relative frequency (m1) of the toner particles included in the most frequent class and the relative frequency (m2) of the toner particles included in the next most frequent class after the most frequent class is 70%. The image forming method according to any one of claims 21 to 23, wherein: 25. The image forming method according to claim 21, wherein the toner is obtained by polymerizing at least a polymerizable monomer in an aqueous medium. 26. The image forming method according to claim 21, wherein the toner is obtained by associating at least resin particles of the toner in an aqueous medium. 27. An image forming apparatus using the image forming method according to claim 1. Description: 28. A photoconductor, and at least one of a charger, an image exposure device, a developing device, a transfer device, a separator, and a cleaning device, using the image forming method according to claim 1. Description: A process cartridge characterized by being made by combining the above.