JP2003307873A - Image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming method by which an image with high image density and high picture quality can be quickly formed in the process of forming an image by developing an electrostatic latent image formed on a photosensitive layer of a photoreceptor with toner. <P>SOLUTION: An image is formed by controlling the ratio [d/v (sec)] of the outer circumference length [d (mm)] of a photoreceptor from the charging position to the developing position to the peripheral velocity of the photoreceptor [v (mm/sec)] to ≤0.50 sec. The surfaces of the toner particles are coated with inorganic fine powder and organic fine powder. The number [NI] of species of the inorganic fine powder is 2 to 5, while the number [N<SB>0</SB>] of species of the organic fine powder is 1 to 3. The total weight [WI] of the inorganic fine powder and the total weight [W<SB>0</SB>] of the organic fine powder with respect to 100 parts by weight of the toner particles, the arithmetical mean particle diameter [DI] obtained by dividing the sum of the mean particle size of each inorganic fine powder by NI, and the arithmetical mean particle diameter [D<SB>0</SB>] obtained by dividing the sum of the mean particle diameter of each organic fine powder by N<SB>0</SB>satisfy the following relations of (1), (2) and (3). They are: (1) 2.0≤WI≤5.0; (2) 0.01≤W<SB>0</SB>≤2.0; and (3) 0.1≤(D<SB>0</SB>×W<SB>0</SB>)/(DI×WI)≤5. <P>COPYRIGHT: (C)2004,JPO

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 in an image forming apparatus such as an electrophotographic copying machine or a printer, and more specifically, an electrostatic latent image formed on a photosensitive layer of a photoconductor by toner. The present invention relates to an image forming method capable of forming an image having high image density and high quality at high speed in developing and forming an image.

[0002]

2. Description of the Related Art Conventionally, as an electrophotographic image forming method, a photosensitive layer having a photosensitive layer formed on a conductive support is uniformly charged, then exposed and exposed. The electrostatic latent image is formed by dissipating the electric charge of the part, and the electrostatic latent image is visualized by developing by attaching the charged toner to the unexposed part, and the obtained visible image is recorded. A method of transferring the image on a transfer material such as paper and fixing the visible image on the transfer material by heating, pressing, etc. is widely used in image forming apparatuses such as copying machines and printers.

On the other hand, with the recent miniaturization and speeding up of the apparatus, it has been required to shorten the time required for the toner to reach the optimum charge amount for development, for example,
Japanese Unexamined Patent Publication No. 6-67452 discloses an image forming method for controlling the charge amount of toner, and various image forming methods including improvements on the photoconductor and the toner surface have been studied. However, it takes time for the toner to reach the desired charge amount, resulting in insufficient density of the image,
Regarding the problems such as fog and ghost, it has not yet been possible to fully satisfy the market demands, and high image quality such as high image density, high resolution, and high gradation that solved those problems. The current situation is that there is a strong demand for this.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned prior art. Therefore, the present invention is to develop the electrostatic latent image formed on the photosensitive layer of the photoconductor with toner. When forming an image with high image density,
An object is to provide an image forming method capable of forming a high quality image at high speed.

[0005]

The present inventor has solved the above-mentioned problems.
As a result of extensive studies to solve the problem, as an external additive for toner
Combine inorganic fine powder and organic fine powder under specific conditions
It was found that the above-mentioned object can be achieved by
That is, the present invention provides a photosensitive layer on the outer peripheral surface.
While rotating the cylindrical photosensitive member having a constant peripheral speed,
Formed on the photosensitive layer by exposing it to
The formed electrostatic latent image is developed with toner to form an image
At this time, the outer peripheral length from the charging position of the photoconductor to the developing position [d
(Mm)] to the peripheral speed [v (mm / sec)] of the photoconductor
Image with a ratio [d / v (second)] of 0.50 seconds or less.
When the toner is
Powder and organic fine powder,
Powder type [N_I], 2 to 5 types, organic fine powder type [N_O〕But
1 to 3 types, which are based on 100 parts by weight of toner particles.
Total weight parts of these inorganic fine powders [W_I], And organic
Total weight of fine powder [W _O], And their minerals
The sum of each average particle size of fine powder is N_IArithmetic mean particle size divided by
[D_I], And the sum of the respective average particle sizes of the organic fine powder is N_O
Arithmetic mean particle size divided by [D_O] Is the following formula (1),
Image formation having the relationship of (2) and (3)
The method is the gist.

2.0 ≦ W _I ≦ 5.0 (1) 0.01 ≦ W _O ≦ 2.0 (2) 0.1 ≦ (D _O × W _O ) / (D _I × W _I ) ≦ 5 (3)

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the image forming method of the present invention,
The photoreceptor has a photosensitive layer formed on a conductive support,
The conductive support is not particularly limited, for example, aluminum, stainless steel, nickel,
Metals such as copper, zinc, indium, silver, and gold, and resin films such as polyester resin, metals such as aluminum, nickel, copper, zinc, and palladium, and tin oxide, indium oxide on an insulating substrate such as paper and paper. A cylinder or a sheet or a belt having a laminated body provided with a vapor-deposited layer of a metal oxide or the like and having a cylindrical shape in which the outer circumference of the drum is covered with them is conventionally used. There are things. In this case, the thickness of the metal sheet is usually about 20 to 500 μm, and the thickness of the metal vapor deposition layer is usually about 400 to 1,000 Å.

The photosensitive layer on the outer peripheral surface of the conductive support is a single layer type composed of one layer in which a charge generating substance and a charge transporting substance are dispersed in a binder resin, or a charge generating substance. The charge generating layer dispersed in the binder resin and the charge transporting layer in which the charge transporting material is dispersed in the binder resin may be either of a laminated type and the latter laminated type is preferable.

In the present invention, the charge-generating substance for the photosensitive layer is not particularly limited, and conventionally known titanium such as Y-type oxytitanium phthalocyanine, α-type oxytitanium phthalocyanine and β-type oxytitanium phthalocyanine. Containing phthalocyanine compound,
And selenium and its alloys such as selenium-tellurium alloys, metal sulfides such as arsenic selenide, zinc sulfide, cadmium sulfide, antimony sulfide, metal oxides such as zinc oxide and titanium oxide, and silicon-based materials such as amorphous silicon Inorganic photoconductive substances such as phthalocyanine, anthraquinone, monoazo, bisazo, trisazo, polyazo, cyanine, perinone, perylene, quinacridone, polycyclic quinone, pyrylium, thiapyrylium Examples thereof include organic photoconductive substances such as various dyes and pigments such as dyes and pigments such as dyes, indigo, thioindigo, anthantrone, and pyrantrone.

In the present invention, titanium-containing phthalocyanine compounds are preferable among the charge generating substances, and Y is preferable.
Type oxytitanium phthalocyanine is particularly preferred. This Y-type oxytitanium phthalocyanine is Bragg-
The Bragg angle (2θ ± 0.2 °) 2 in the X-ray diffraction spectrum by CuKα ray by the Brentano concentration method
A crystalline oxytitanium phthalocyanine having a maximum diffraction peak at 7.3 °, which is disclosed in, for example, JP-A-62-6.
FIG. 2 of Japanese Patent Publication No. 7094 (referred to as “II type” in the publication), FIG. 1 of Japanese Patent Application Laid-Open No. 2-8256, Vol. 92, No. 3 of the Institute of Electrophotography (issued in 1990). ) 25th
0 to 258 (referred to as "Y type" in the same magazine), etc., and the maximum diffraction peak at 27.3 ° is 24.2 °, 9.7 °, and It also has a diffraction peak at 7.4 °. Further, in the present invention, it is preferable that the ratio of the area at the diffraction peaks 24.2 °, 9.7 °, and 7.4 ° to the area at the maximum diffraction peak 27.3 ° is 40% or less.

When a charge-generating substance other than the Y-type oxytitanium phthalocyanine is contained and only the other titanium-containing phthalocyanine-based compound is contained, the ratio of the Y-type oxytitanium phthalocyanine to the total charge-generating substance is contained. Is preferably 30% by weight or more, more preferably 50% by weight or more, and particularly preferably 70% by weight or more. When the charge generating substance other than the titanium-containing phthalocyanine compound is contained, the proportion of Y-type oxytitanium phthalocyanine in the total charge generating substance is preferably 40% by weight or more, and 60% by weight or more. Is more preferable, and 80% by weight or more is particularly preferable.

The charge-transporting substance for the photosensitive layer is not particularly limited, and conventionally known organic polymer compounds such as polyacenaphthylene, polyvinylanthracene, polyvinylpyrene, polyvinylcarbazole and the like,
Aromatic hydrocarbon compounds such as styrene and stilbene, and derivatives thereof, quinone compounds such as benzoquinone, naphthoquinone, anthraquinone, diphenoquinone and derivatives thereof,
Nitrogen-containing compounds such as aryl-substituted amines and aryl-substituted hydrazones and their derivatives, carbazole, acridine,
Pyrazoline, imidazole, benzimidazole, imidazolidine, imidazolone, phenazine, triazole and other nitrogen-containing heterocyclic compounds and derivatives thereof, thiazole, thiadiazole, benzothiazole and other nitrogen-containing sulfur-containing heterocyclic compounds and derivatives thereof, oxazole, oxa Examples thereof include nitrogen-containing oxygen-containing heterocyclic compounds such as diazoles and organic low-molecular compounds such as derivatives thereof.

The binder resin for the photosensitive layer is also not particularly limited, and is conventionally known, for example, styrene, butadiene, acrylic acid, methacrylic acid, acrylic acid ester, methacrylic acid ester, acrylonitrile, vinyl acetate, Examples thereof include homopolymers or copolymers of vinyl compounds such as vinyl chloride, vinyl alcohol, vinyl butyral, and vinylpyrrolidone, saturated polyester resins, polycarbonate resins, polyamide resins, polyarylate resins, and polysulfone resins.

The content ratio of the charge generating substance, the charge transporting substance and the binder resin in the photosensitive layer is 0.5 to 0.5 parts by weight of the binder resin with respect to 100 parts by weight of the charge generating substance in the laminated charge generating layer. It is preferably 500 parts by weight, more preferably 20 to 300 parts by weight. In addition, in the laminated charge transport layer, 100 to 3 parts by weight of the charge transport material is added to the binder resin 100 to 3
The amount is preferably 00 parts by weight, more preferably 150 to 250 parts by weight.

In the present invention, the photosensitive layer may contain additives such as a plasticizer, an antioxidant, a heat stabilizer, an ultraviolet absorber, an antistatic agent, a lubricant, a release agent and a flame retardant, if necessary. May be added.

An undercoat layer may be provided between the conductive support and the photosensitive layer, and the undercoat layer is alumina, silica, titania, iron oxide, zinc oxide,
Fine powders of metal oxides such as zirconium oxide, calcium titanate, strontium titanate, metal titanates such as barium titanate, titanium nitride, nitrides such as silicon nitride, titanium carbide, carbides such as silicon carbide, Usually, it is dispersed in a binder resin such as polyacrylic acid, polyvinyl alcohol, polyvinyl butyral, polyvinylpyrrolidone, polyurethane resin, polyamide resin, cellulose, casein, epoxy resin, phenol resin, melamine resin, etc., and their fine powder and binder. The resin is dissolved or dispersed in a solvent or a dispersion medium to form a coating liquid, which is applied to the surface of the support and dried to preferably 0.05 to 20 μm, more preferably 0.1 to 10 μm.
Is formed with a thickness of.

In the case of a single-layer type photosensitive layer, the laminated structure of the photoreceptor of the present invention includes, for example, support / photosensitive layer, support / undercoating layer / photosensitive layer, and the like. In the case of, for example, support / charge generation layer / charge transport layer,
Support / charge transport layer / charge generation layer, support / undercoat layer /
Examples include charge generation layer / charge transport layer, support / undercoat layer / charge transport layer / charge generation layer, and the like.

Further, a surface protective layer containing the above-mentioned binder resin or the like as a main component is further preferably formed on the surface of the photoreceptor having various laminated structures, preferably in the range of 0.01 to 20 μm, more preferably 0.1 to 20 μm. It may be provided with a thickness of 10 μm.

In the case of a single-layer type, the photosensitive layer of the photosensitive member of the present invention is formed on the conductive support by using the charge generating substance, the charge transporting substance, the binder resin, the additive and the like. In the case of a laminated type, as the coating liquid dissolved or dispersed in a solvent or a dispersion medium, the charge generating substance,
And the binder resin, additives, etc., as a coating liquid dissolved or dispersed in a solvent or a dispersion medium, and the charge transport material, and the binder resin, additives, etc.,
As a coating solution dissolved or dispersed in a solvent or a dispersion medium, on the support, or on the undercoating layer formed thereon, as a dry film thickness, in the case of a single layer type, preferably 5 to 60 μm , More preferably 10 to 45 μm,
In the case of a laminated type, the charge generation layer is preferably 0.05 to 5 μm.
m, more preferably 0.1 to 2 μm, and the charge transport layer is preferably 10 to 60 μm, more preferably 15 to 40 μm.
It is made by coating so that

The solvent or dispersion medium used for preparing the coating liquid at that time is, for example, methyl alcohol,
Alcohols such as ethyl alcohol and propyl alcohol, methyl formate, ethyl acetate, methyl cellosolve, methyl cellosolve acetate, tetrahydrofuran, 1,4
-Ethers such as dioxane, esters such as ethyl acetate and butyl acetate, ketones such as acetone, methyl ethyl ketone and cyclohexanone, aromatic hydrocarbons such as benzene, toluene and xylene, chloroform, dichloromethane, 1,2-dichloroethane, 1,
Chlorinated hydrocarbons such as 1,2-trichloroethane, 1,1,1-trichloroethane, tetrachloroethane, 1,2-dichloropropane and trichloroethylene, n-butylamine, isopropanolamine, diethylamine, triethanolamine, ethylenediamine, triethylenediamine Nitrogen-containing compounds such as acetonitrile,
Examples thereof include aprotic polar solvents such as N-methylpyrrolidone, N, N-dimethylformamide, and dimethylsulfoxide, and these may be used alone or in combination of two or more kinds.

Examples of the coating method at that time include a dipping method, a spray method, a bar coater method, a blade method, a roll coater method, a wire bar method and a knife coater method. Drying is performed with hot air. Using a dryer, a steam dryer, an infrared dryer, a far infrared dryer, or the like, the temperature is usually in the range of 100 to 250 ° C, preferably 110 to 170 ° C.

Further, in the present invention, the toner for developing the electrostatic latent image formed on the photosensitive layer of the photoconductor is such that the surface of toner particles having a colorant and a binder resin as a basic composition is coated with fine powder. Become.

As the colorant in the toner particles, various inorganic and organic dyes and pigments generally used as colorants for toners of this type are used. Examples of the inorganic dyes and pigments include: Carbon black, lamp black, iron oxide, manganese oxide, copper oxide, chromium oxide,
Dark blue, ultramarine, and the like, as organic dyes and pigments, for example,
Phthalocyanine, anthraquinone, quinone, monoazo, bisazo, trisazo, polyazo, triphenylmethane, cyanine, perinone, perylene, quinacridone, polycyclic quinone, pyrylium, thiapyrylium, indigo System, thioindigo system, antoanthrone system, pyrantrone system, isoindoline system, thiazine system, nigrosine system, rhodamine system and the like, respectively.

Further, the coloring agent may have magnetism, and as the magnetic coloring agent, a ferromagnetic substance exhibiting ferrimagnetism or ferromagnetism at around 0 to 60 ° C. which is an operating environment temperature of a copying machine or the like. Specifically, for example, magnetite (Fe ₃ O ₄ ), maghematite (γ-Fe ₂ O ₃ ),
An intermediate between magnetite and maghematite, ferrite (M _x Fe _{3 -x} O ₄ ; in the formula, M is Mg, Mn, Fe,
Co, Ni, Cu, Zn, Cd, etc.) spinel ferrite, BaO.6Fe ₂ O ₃ , hexagonal ferrite such as SrO.6Fe ₂ O ₃ , Y ₃ Fe ₅ O ₁₂ , Sm ₃ Fe ₅ O
_Among garnet-type oxides such as ₁₂ and rutile-type oxides such as CrO ₂ , and metals such as Cr, Mn, Fe, Co and Ni or their ferromagnetic alloys, ferrimagnetic or near 0 to 60 ° C. Some of them exhibit ferromagnetism,
Among them, magnetite, maghematite, or an intermediate of magnetite and maghematite is preferable.

Also, the binder resin in the toner particles is not particularly limited, and is conventionally known, for example, styrene, butadiene, acrylic acid, methacrylic acid, acrylic acid ester, methacrylic acid ester, acrylonitrile, vinyl acetate, Vinyl chloride, vinyl alcohol, vinyl butyral, homopolymers or copolymers of vinyl compounds such as vinylpyrrolidone, saturated polyester resins, polycarbonate resins, polyamide resins, polyolefin resins, polyarylate resins, polysulfone resins,
Examples thereof include polyphenylene ether resin, unsaturated polyester resin, phenol resin, epoxy resin, urethane resin, and rosin-modified maleic acid resin.

The content ratio of the colorant in the toner particles is 1 to 100 parts by weight of the binder resin.
It is preferably 20 parts by weight, more preferably 2 to 15 parts by weight.

Further, the toner particles in the present invention preferably contain a charge control agent, and as the charge control agent, there are conventionally known charge controlling agents such as nigrosine dye, quaternary ammonium salt compound and triphenyl. Methane compounds,
Positively chargeable charge control agents such as imidazole compounds and polyamine resins, or chromium, cobalt, aluminum,
Metal-containing azo dyes such as iron, metal salts and metal complexes of salicylic acid or alkylsalicylic acid chromium, zinc, aluminum, etc., metal salts and metal complexes of benzylic acid, amide compounds, phenol compounds, naphthol compounds, phenolamide compounds, etc. Examples of negative charge control agents include
Of the following general formulas (I), (II), (III), (IV), and (V)
And a compound represented by the following general formula (I), (III),
And a metal salt or complex of the compound represented by (IV), and a boron complex of the compound represented by the following general formula (IV) are particularly preferable.

[0028]

[Chemical 1]

[In the formula (I), A, B, C, and D each independently represent an aromatic ring which may have a substituent, and Q
Represents a direct bond or a divalent linking group. ]

Examples of the aromatic ring represented by A, B, C and D in the formula (I) include benzene ring, naphthalene ring, anthracene ring, phenanthrene ring and the like. Among them, benzene ring, Or a naphthalene ring is preferable,
A benzene ring is particularly preferred. Further, as the substituents on these aromatic rings, for example, a hydrocarbon group, an alkoxy group, an alkylthio group, a dialkylamino group, a nitro group,
A cyano group, a hydroxyl group, a halogen atom and the like can be mentioned.
A halogen atom is preferred. Examples of the divalent linking group for Q include an oxygen atom, a sulfur atom, an alkylene group, an alkenylene group, an alkylimino group, and the like, and among them, the number of carbon atoms which may have a substituent is 1 to 1. An alkylene group of 4,
Alternatively, an alkenylene group having 2 to 4 carbon atoms which may have a substituent is preferable. The metal in the metal salt or metal complex of the compound of formula (I) is preferably an alkali metal or an alkaline earth metal, particularly preferably potassium or sodium.

[0031]

[Chemical 2]

[In the formula (II), R ¹ and R ² each independently represent a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, a halogen atom or a hydrogen atom, and R 1 ³ and R
⁴ are each independently C 1 which may have a substituent
~ 5 hydrocarbon groups or hydrogen atoms, n and m are
It is an integer of 0 or more, and n + m is 4 to 10. ]

Here, R in the formula (II)¹, R²,
R³, And R^FourAs, charcoal which may have a substituent
An alkyl group having a prime number of 1 to 5 or a hydrogen atom is preferable, and R is
¹And R ²Has 3 to 5 carbon atoms which may have a substituent.
An alkyl group, R³And R^FourIs a hydrogen atom
Particularly preferred. Also, it is preferable that n + m is 6 to 9.
It is particularly preferable that it is 8.

[0034]

[Chemical 3]

[In the formula (III), R ⁵ and R ⁶ each independently represent a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or a hydrogen atom. ]

Here, R ⁵ and R ⁶ in the formula (III) are preferably an alkyl group having 3 to 5 carbon atoms which may have a substituent. As the metal in the metal salt or metal complex of the compound of formula (III), a divalent or trivalent metal is preferable, and chromium, aluminum or zinc is particularly preferable.

[0037]

[Chemical 4]

[In the formula (IV), E and F each independently represent an aromatic ring which may have a substituent. ]

Here, examples of the aromatic ring of E and F in the formula (IV) include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring and the like, among which a benzene ring or an anthracene ring is preferable, A benzene ring is particularly preferred. Further, examples of the substituent in these aromatic rings include a hydrocarbon group, an alkoxy group, an alkylthio group, a dialkylamino group, a nitro group, a cyano group, a hydroxyl group, a halogen atom and the like. Are preferred. As the metal in the metal salt or metal complex of the compound of formula (IV), a divalent or trivalent metal is preferable, and chromium, aluminum or zinc is particularly preferable. Also preferred is a boron complex of the compound of formula (IV).

[0040]

[Chemical 5]

[In the formula (V), R ⁷ , R ⁸ , R ⁹ and R ¹⁰
Each independently has 1 to 1 carbon atoms which may have a substituent.
5 hydrocarbon groups, nitro groups, cyano groups, halogen atoms,
Or a hydrogen atom, R ¹¹ and R ¹² are each independently N
A phenylcarbamoyl group or a hydrogen atom, M
Represents a trivalent metal, and X ⁺ represents a proton, an ammonium ion, or an alkali metal ion. ]

Here, R ⁷ , R ⁸ in the formula (V),
At least one of R ⁹ and R ¹⁰ is preferably a nitro group or a chlorine atom, M is preferably chromium or iron, and X ⁺ is a proton, potassium ion, or sodium. Ions are preferred.

The content ratio of the charge control agent in the toner particles is preferably 0.01 to 10 parts by weight, and 0.1 to 5 parts by weight, based on 100 parts by weight of the binder resin.
More preferably, it is parts by weight.

Further, in the present invention, it is preferable that the toner particles further contain waxes for the purpose of improving releasability at the time of fixing to the transfer material, and the waxes are conventionally known. , For example, low molecular weight polyethylene, low molecular weight polypropylene, polyolefin wax such as low molecular weight ethylene-propylene copolymer, paraffin wax, stearic acid ester, behenic acid ester,
Ester waxes having long chain aliphatic groups such as montanic acid esters, hydrogenated castor oil, plant waxes such as carnauba wax, ketones having long chain alkyl groups such as distearyl ketone, silicones having alkyl groups, stearic acid And higher fatty acids, long-chain fatty alcohols, (partial) esters of pentaerythritol and the like with long-chain fatty acids, and higher fatty acid amides such as oleic acid amide and stearic acid amide. Also, low molecular weight polytetrafluoroethylene and the like are useful. The waxes in the present invention preferably have a melting point of 50 to 100 ° C.

The content of the waxes in the toner particles is preferably 0.1 to 25 parts by weight, more preferably 5 to 15 parts by weight, based on 100 parts by weight of the binder resin.

Further, in the present invention, the toner particles include various known internal additives for modifying the toner's tackiness, cohesiveness, fluidity, chargeability, surface resistance, etc., such as silicone oil and silicone. It may contain a varnish or the like.

The method for producing the toner particles in the present invention is not particularly limited, and for example, the colorant, the powdery particles of the binder resin, the charge control agent, the waxes, etc. may be used, for example. After uniformly mixing with a mixer such as a tumbler blender, a ribbon blender, a V-type blender, a Henschel mixer, and a super mixer, the mixture is melt-kneaded with a kneader such as a uniaxial or biaxial extruder to obtain a resin composition for toner particles. None, the resin composition is coarsely pulverized or further medium pulverized by, for example, a jaw crusher, a gyratory crusher, a roll mill, a hammer mill, a feather mill, etc., and an average particle diameter is usually about 50 to 3,000 μm, preferably About 50-500
After forming coarse particles of about μm, the coarse particles are finely pulverized by, for example, a roll mill, a hammer mill, a ball mill, a jet mill or the like into a powder of about several tens of μm or less, and the obtained powder is subjected to, for example, inertia classification. System elbow jet, centrifugal force classifying microplex, DS separator, etc. to classify toner particles of a specified particle size, and then, if necessary, spheronizing means such as mechanofusion method or surffusion method. Pulverization method, or the binder resin component monomer, the colorant, and the charge control agent,
A suspension polymerization method in which suspension polymerization is performed in the presence of the wax or the like, an emulsion obtained by emulsion polymerization of the binder resin component monomer is stirred in the presence of the colorant, the charge control agent, the wax or the like. Examples thereof include an emulsion polymerization aggregation method in which emulsion particles are aggregated (associated).

Among these, in the present invention, the emulsion polymerization aggregation method is preferable, and in this case, it is preferable to use the fine particles of the wax as a seed in the emulsion polymerization of the binder resin component monomer to perform seed polymerization.

The toner according to the present invention is obtained by coating the surface of the toner particles with an inorganic fine powder and an organic fine powder, and as the inorganic fine powder, there are conventionally known ones such as alumina and silica. Titania, zinc oxide,
Metal oxides / hydroxides of zirconium oxide, cerium oxide, talc, hydrotalcite, etc., metal titanate salts of calcium titanate, strontium titanate, barium titanate, etc., nitrides such as titanium nitride, silicon nitride, etc. Titanium, carbides such as silicon carbide, and ferrite, magnetic powders such as magnetite, and as organic fine powders thereof, conventionally known, for example, styrene resins, acrylic resins, benzoguanamine resins, resins such as melamine resins, And, for example, calcium oleate, zinc oleate,
Examples include higher fatty acid metal salts such as calcium stearate and zinc stearate. Among these,
Alumina, silica and titania are preferable as the inorganic fine powder, and styrene resin and acrylic resin are preferable as the organic fine powder.

The average particle size of these fine powders is preferably 0.01 to 1 μm in the inorganic fine powder,
More preferably, it is 0.01 to 0.5 μm. Further, in the organic fine powder, it is preferably 0.05 to 3 μm, more preferably 0.1 to 1 μm. still,
Here, the average particle diameter is obtained as an arithmetic average value of particle diameters of 500 arbitrary particles measured by a transmission electron microscope, and when it is not circular, it is equal to the area of a projected image by image processing. The diameter of the circle was defined as the particle size.

The inorganic fine powder is preferably, for example, one surface-treated with a silane coupling agent, silicone oil or the like, whereby the degree of hydrophobization is preferably 50 or more, and 60 or more. Is more preferable. In addition, here, the degree of hydrophobicity is 0.20 g of a precisely weighed sample.
Was collected in a beaker, 50 ml of pure water was added, and methanol was injected onto the liquid surface while stirring with a magnetic stirrer. From the injection amount of methanol at the time when no sample was observed on the liquid surface, It is calculated. Hydrophobicity = [methanol injection amount / (50 + methanol injection amount)] × 100

In the present invention, the inorganic fine powder type [N _I ] is 2 to 5 types, the organic fine powder type [N _O ] is 1 to 3 types, and it is based on 100 parts by weight of the toner particles. The total weight part [W _I ] of the inorganic fine powder, the total weight part [W _O ] of the organic fine powder, and the sum of the average particle diameters of the inorganic fine powder are N _I.
Arithmetic average particle diameter was divided in [D _I], and an arithmetic average particle diameter of the total of the average particle size divided by N _O of the fine organic fine powder [D _O]
Must have the relationships of the following formulas (1), (2), and (3).

2.0 ≦ W _I ≦ 5.0 (1) 0.01 ≦ W _O ≦ 2.0 (2) 0.1 ≦ (D _O × W _O ) / (D _I × W _I ) ≦ 5 (3)

Total weight part of the inorganic fine powder [W_I〕But
Less than the above range, and the total weight part of the organic fine powder
[W_O] If the above range is exceeded, the fluidity of the toner will be poor.
On the other hand, the total weight of the inorganic fine powder is decreased.
Quantity part [W_I] If the above range is exceeded, the film
And the total weight of the organic fine powder is
Quantity part [W_OIs less than the above range, the toner is charged as a toner.
Becomes unstable, and the image of the obtained image is
The quality will be reduced. In addition, the above [(D_O× W _O) /
(D_I× W_I)] Is a high-quality image even if the value is outside the above range.
Will be difficult to obtain.

In the present invention, in order to coat the surface of the toner particles with the inorganic fine powder and the organic fine powder to form a toner, the inorganic fine powder and the organic fine powder are added to the toner particles. Then, the mixture is uniformly stirred and mixed by a mixer such as a Henschel mixer.

The toner of the present invention has a particle size distribution of 50 when measured with a Multisizer manufactured by Coulter.
% Of volume average particle diameter [D _v (μm)] at cumulative frequency of 5
The ratio [D _v / D _n ] to the number average particle size [D _n (μm)] at 0% cumulative frequency is preferably 1.0 to 1.25, and 1.0 to 1.20. Is more preferable. Further, the proportion of particles having a particle size of 5.0 μm or less is 10 number% or more, the proportion of particles of 8.0 to 12.7 μm is 40 number% or less, and the proportion of particles of 16.0 μm or more is 2 number% or less, Moreover, it is particularly preferable that the volume average particle diameter [D _v ] at a cumulative frequency of 50% is 4 to 10 μm.

The circularity at a cumulative frequency of 50% of the circularity calculated by the following equation using a flow type particle image analyzer "FPIA-2100" manufactured by Sysmex Co.
Preferably, it has 0.92 to 1.0,
More preferably, it has 0.94 to 1.0. Circularity = circumference of a circle having the same area as the area of the particle projection image / circumference of the particle projection image

Here, the "circularity at a cumulative frequency of 50% of the circularity" means the circularity 0 to 1 obtained by the above equation.
Represents the circularity at the 50% cumulative frequency in the distribution curve with the horizontal axis as the horizontal axis and the cumulative frequency as 0 to 100% as the vertical axis.

Also, a dynamic viscoelasticity measuring device "MR" manufactured by UBM
-500 ", frequency 1H on parallel plate
The storage elastic modulus measured under the condition of z is the value measured at 150 ° C. for the toner for single color and the value measured at 120 ° C. for the toner for full color, and the storage elastic modulus at 1% strain [G It is _{preferable that} “ _1% (Pa)” and the storage elastic modulus at 30% strain [G ′ _30% (Pa)] have the relationship of the following formulas (4) and (5).

1.0 × 10 ² ≦ G ′ _1% ≦ 1.0 × 10 ⁴ (4) 1.0 ≦ G ′ _1% / G ′ _30% ≦ 10.0 (5)

As the toner in the present invention, a magnetic two-component coexisting magnetic powder such as ferrite or magnetite as a carrier for conveying the toner to the electrostatic latent image portion by magnetic force, or those magnetic powders are used as the toner. It may be either a magnetic one-component contained in the toner, or a non-magnetic one-component without using magnetic powder in the toner, but a non-magnetic one-component,
Alternatively, it is preferably for magnetic single component. As the magnetic powder as a carrier, for example, polyvinylidene fluoride,
Those surface-treated with a fluororesin such as polytetrafluoroethylene are preferred.

The image forming method of the present invention will be described with reference to the drawings when a non-magnetic one-component toner is used.
FIG. 1 is a schematic view showing an embodiment of an image forming apparatus used in the image forming method of the present invention, in which 1 is a photosensitive member, 1a is a conductive support, 1b is a photosensitive layer, 2 is a charging device, and 3 is a charging device. Is an exposure device, 4 is a developing device, 4a is a developing roller, 4b is a toner supply roller, 4c is a blade, 4d is an agitator, 5 is a transfer device, 6 is a cleaning device, 7 is a fixing device, and 7a.
Is a lower fixing member, 7b is an upper fixing member, 7c is a heating device, T is toner, and P is recording paper. The charging device 2, the exposure device 3, the developing device 4, the transfer device 5, and the cleaning device 6 are photosensitive. It is arranged along the outer peripheral surface of the body 1.

Here, the photosensitive member 1 is made of a conductive metal such as aluminum, and is formed on the outer peripheral surface of the drum-shaped support member 1a which is rotatable by a rotary drive mechanism (not shown). And a photosensitive layer 1b. Also, the charging device 2
Is composed of a scorotron charger, a roller charger, and the like arranged in contact with the outer peripheral surface of the photoconductor 1, and uniformly charges the surface of the photoconductor 1 to a predetermined potential. Also, the exposure apparatus 3 is LE
D, a light source irradiating device such as a laser beam, and forms an electrostatic latent image on the photosensitive layer 1b of the photosensitive member 1.

The developing device 4 is composed of a metal roll of iron, stainless steel, aluminum, nickel or the like, or a metal roll of which the outer peripheral surface is coated with silicon resin, fluorine resin, urethane resin or the like. And a developing roller 4a which is arranged so as to be in contact with the outer peripheral surface of the photosensitive drum 1 so as to be rotatable by a rotary drive mechanism (not shown) and which brings the toner T carried on the outer peripheral surface into contact with the outer peripheral surface of the photoconductor 1. And the like, which is abutted against the developing roller 4a and is rotatably arranged by a rotation driving mechanism (not shown), and carries the toner T stored in the developing device 4 and supplies it to the developing roller 4a. Roller 4b and resin such as silicon resin or urethane resin, metal such as stainless steel, aluminum, copper, brass, phosphor bronze, or metal whose surface is coated with resin Thus, the outer peripheral surface of the developing roller 4a is pressed by a spring or the like, and the blade 4c for regulating the layer thickness of the toner T supplied to the outer peripheral surface of the developing roller 4a by the toner supply roller 4b, and a rotation driving mechanism. It has a blade shape that can be rotated by (not shown), and is composed of an agitator 4d that agitates the toner T stored in the developing device 4.

The transfer device 5 is composed of a transfer charger, a transfer roller, a transfer belt, and the like, which are arranged in contact with the outer peripheral surface of the photoconductor 1, and have a polarity opposite to the charging potential of the toner T and a predetermined voltage. The applied toner image formed on the photoconductor 1 is transferred to the recording paper P. The cleaning device 6 includes a cleaning member such as a blade and a fur brush, and scrapes off the toner T remaining on the outer peripheral surface of the photoconductor 1. or,
The fixing device 7 has the same material as the lower fixing member 7a including a roller in which a metal tube made of stainless steel, aluminum or the like is coated with a silicon resin, a fluororesin or the like, or a sheet in which a metal sheet is coated with a resin or the like. And an upper fixing member 7b provided in pressure contact with the lower fixing member 7a, and a heating device 7c is internally provided in any one of the members 7a and 7b (the upper fixing member 7b in the drawing). The toner T in the toner image on the recording paper P is heated to a molten state and fixed on the recording paper P.

Then, in the image forming method of the present invention,
While rotating the cylindrical photoreceptor 1 having the photosensitive layer 1b on the outer peripheral surface of the conductive support 1a at a constant peripheral speed, its surface is uniformly charged to a predetermined potential by the charging device 2, and then,
The exposed toner is exposed by the exposure device 3 to dissipate the electric charge in the exposed portion to form an electrostatic latent image on the photosensitive layer 1b, and the unexposed portion is charged toner carried on the developing roller 4a of the developing device 4. By attaching T, the electrostatic latent image is visualized and developed, the obtained toner image is transferred to the recording paper P by the transfer device 5, and the transferred toner T on the recording paper P is fixed by the fixing device. The heating and pressure are applied by means of 7 to fix the recording paper P. The outer peripheral surface of the photoconductor 1 is cleaned by the cleaning device 6,
The same operation as described above is repeated.

At this time, in the image forming method of the present invention, the outer peripheral length [d] from the charging position to the developing position of the photosensitive member 1
(Mm)] to the peripheral speed [v (mm / sec)] of the photoconductor 1 [d / v (sec)] is 0.50 sec or less to form an image.

[0068]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. In addition, each production example of the photoconductor and the toner particles used in the following Examples and Comparative Examples, and the inorganic fine powder and the organic fine powder are shown below.

<Production Example 1 of Photoreceptor> On a cylindrical aluminum support having a diameter of 30 mm, Cu was used as a charge generating substance.
Bragg angle (2θ ± 0.2 °) 27.3 °, 24.2 °, 9.7 in X-ray diffraction spectrum by Kα ray
Coating solution containing 200 parts by weight of Y-type oxytitanium phthalocyanine having a diffraction peak at 7 ° and 7.4 °, and 100 parts by weight of polyvinyl butyral (“Denka butyral # 6000C” manufactured by Denki Kagaku Kogyo Co., Ltd.) as a binder resin. Then, a charge generation layer having a thickness of 0.4 μm is formed by drying, and 70 parts by weight of N-methyl-3-carbazolecarbaldehydediphenylhydrazone as a charge transport material and a polycarbonate resin ( Mitsubishi Chemical Corporation "Novarex 8025
A ”) 100 parts by weight, and a coating solution containing 2 parts by weight of p-nitrobenzoyloxybenzalmalononitrile are applied and dried to form a charge transport layer having a film thickness of 15 μm. Was prepared.

<Production Example 1 of Toner Particles> As a colorant,
40% by weight of cyan pigment (Pigment Blue 15: 3)
10 parts by weight of masterbatch, 100 parts by weight of saturated polyester resin as a binder resin, 1 part by weight of a boron complex of benzylic acid which is a compound of the general formula (IV) as a charge control agent ("LR-147" manufactured by Japan Carlit Co., Ltd.), And 5 parts by weight of paraffin wax having a melting point of 80 ° C. are mixed in a Henschel mixer, and then melt-kneaded using a twin-screw extruder to prepare a resin composition for toner, and after cooling, coarsely crushed by a hammer mill, Then, finely pulverized by a supersonic jet mill, the obtained powder was classified by an air classifier, and further spheroidized by a surffusion method to produce toner particles.

<Production Example 2 of Toner Particles> The same procedure as in Production Example 1 of toner particles described above except that the paraffin wax was not used and the spheroidizing treatment by the surffusion method was not performed. , Toner particles were produced.

<Production Example 3 of Toner Particles> Ester wax containing tetrastearic acid ester of pentaerythritol as a main component (“UNISTAR H476” manufactured by NOF CORPORATION).
0 "30 parts by weight together with sodium dodecylbenzene sulfonate 1.67 parts by weight and demineralized water 68.33 parts by weight, and emulsified under high pressure shearing to obtain ester wax fine particles having an average particle size of 0.26 μm. An emulsion was prepared, and then 53.1 parts by weight of the ester wax emulsion obtained above and 406 parts by weight of demineralized water were charged into a reactor having an internal volume of 3 liters, and the mixture was stirred under a nitrogen stream for 90 minutes.
After the temperature was raised to ℃, 1.6 parts by weight of 8% hydrogen peroxide aqueous solution and 1.6 parts by weight of 8% ascorbic acid aqueous solution were added, followed by 80 parts by weight of styrene and 20 parts of butyl acrylate.
Parts by weight, acrylic acid 1 part by weight, hexanediol diacrylate 0.8 parts by weight, and a mixture of 0.45 parts by weight of trichlorobromomethane as a chain transfer agent and 0.01 parts by weight of 2-mercaptoethanol, and 10 weight%
An emulsifier aqueous solution of 1 part by weight of sodium dodecylbenzenesulfonate aqueous solution and 25 parts by weight of demineralized water was added over 5 hours, and 9 parts by weight of 8% hydrogen peroxide aqueous solution and 9 parts by weight of 8% ascorbic acid aqueous solution were added over 6 hours. In addition, the emulsion was copolymerized with the ester wax fine particles as a seed under stirring and cooled to obtain a primary particle emulsion of a styrene-butyl acrylate-acrylic acid-based copolymer. Then, 100 parts by weight of the polymer primary particle emulsion obtained above as a solid content and 0.5 part by weight of a 10% by weight sodium dodecylbenzenesulfonate aqueous solution were charged into a reactor having an internal volume of 1 liter and mixed uniformly. Later, a cyan pigment as a colorant (Pigment Blue 1
5.7 parts by weight of a 35% by weight aqueous dispersion of 5: 3) was added as a solid content and uniformly mixed, and subsequently 0.6 part by weight of aluminum sulfate was added dropwise as an aqueous solution, and the mixture was stirred under a 2
The temperature was raised to 50 ° C. over 0 minutes and kept for 1 hour, and further raised to 53 ° C. over 6 minutes, and when the volume average particle diameter reached 7.1 μm, aluminum sulfate was again made into an aqueous solution. 0.07 parts by weight was added dropwise, the temperature was raised to 55 ° C. over 10 minutes with stirring, the temperature was maintained for 30 minutes, and further 3 parts by weight of a 10% by weight sodium dodecylbenzenesulfonate aqueous solution was added.
The temperature was raised to 95 ° C. over 35 minutes with stirring, and the temperature was maintained for 3.5 hours, followed by cooling, filtration, washing with water, and drying to produce toner particles as the primary particle aggregates.

<Inorganic Fine Powder> (1) Silica having an average particle size of 0.04 μm and a degree of hydrophobization of 70. (2) Silica having an average particle size of 0.015 μm and a degree of hydrophobicity of 60. (3) Silica having an average particle diameter of 0.012 μm and a degree of hydrophobicity of 70. (4) Titania having an average particle size of 0.015 μm and a degree of hydrophobization of 70. <Organic fine powder> (1) Acrylic resin beads having an average particle size of 0.3 μm. (2) Styrene resin beads having an average particle size of 0.2 μm.

Examples 1 to 3 Inorganic fine powders and organic fine powders shown in the following Table 1 were added to 100 parts by weight of the toner particles of Production Example 1, and each toner was produced by stirring and mixing with a Henschel mixer. .

The obtained toner has a particle size distribution measured by using Multisizer manufactured by Coulter Co., which is a ratio [D _v / _Dv ] of the volume average particle size [D _v ] to the number average particle size [D _n ].
D _n ] is 1.16, the proportion of particles having a particle size of 5.0 μm or less is 12.2% by number, and the proportion of particles of 8.0 to 12.7 μm is 9.9% by number, 16. The proportion of particles of 0 μm or more was 0.3% by number, the volume average particle diameter [D _v ] was 7.9 μm, and measurement was performed using a flow particle image analyzer “FPIA-2100” manufactured by Sysmex Corporation. The circularity is 0.93, and using a dynamic viscoelasticity measuring device "MR-500" manufactured by UBM, a 1% strain was measured by a parallel plate at a frequency of 1 Hz and at 120 ° C. Storage elastic modulus [G ′ _1% ] is 5.8 × 10 ³ Pa, storage elastic modulus [G ′ _30% ] at 30% strain is 2.9 × 10 ³ Pa,
G'1 _% / G '30 _% was 2.0.

Subsequently, using the image forming apparatus shown in FIG. 1, the outer peripheral length [d] from the charging position to the developing position of the photosensitive member is 23.6 mm, and the peripheral speed [v] of the photosensitive member is 250 m.
m / sec, and the ratio [d] of peripheral length [d] to peripheral speed [v]
/ V] is set to 0.09 seconds and the electrostatic latent image formed on the photosensitive layer of the photoconductor of Production Example 1 is developed with each of the toners described above in an environment of a temperature of 25 ° C. and a relative humidity of 60%. The image quality such as image density, resolution, and gradation of the image on each recording paper obtained in the initial stage and after 5,000 actual images were recorded by “10” panelists “good”, “ The result was evaluated according to the following criteria, and the results are shown in Table 1 below.

⊚: 10 people judged to be good. ○: 9 people judged to be good. Δ: 5 to 8 people judged to be good. X: 4 or less people judged to be good.

Example 4 Toners prepared by adding the inorganic fine powders and the organic fine powders shown in Table 1 below to 100 parts by weight of the toner particles of Production Example 3 and stirring and mixing with a Henschel mixer were used. An image was formed in the same manner as in Example 1 and the image characteristics thereof were evaluated. The results are shown in Table 1 below.

The obtained toner had a particle size distribution measured using a Multisizer manufactured by Coulter, and the ratio [D _v ] of the volume average particle size [D _v ] to the number average particle size [D _n ] was [D _n ].
_v / D _n] is 1.18, and the proportion of particles smaller than the particle diameter 5.0μm 12.0 number%, 8.0～12.7Myu
The ratio of particles of m is 16.1% by number, the ratio of particles of 16.0 μm or more is 0.3% by number, and the volume average particle diameter [D
_v ] is 7.5 μm, the circularity measured using a flow particle image analyzer “FPIA-2100” manufactured by Sysmex Co. is 0.95, and the dynamic viscoelasticity measuring device “MR” manufactured by UBM Co. -500 ", the storage elastic modulus at 1% strain [G'1 _% ] measured at 120 ° C in a parallel plate at a frequency of 1 Hz is 4.3 x 10 ³ Pa, 30.
Storage elastic modulus at ₃₀ % strain [G ′ _30% ] is 1.9 × 10 ³ P
a, G'1 _% / G '30 _% was 2.3.

Comparative Example 1 Inorganic fine powder and organic fine powder shown in the following Table 1 were added to 100 parts by weight of the toner particles of Production Example 2, and the toner produced by stirring and mixing with a Henschel mixer was used. An image was formed in the same manner as in Example 1 and the image characteristics thereof were evaluated. The results are shown in Table 1 below.

The obtained toner had a particle size distribution measured using a Multisizer manufactured by Coulter, and the ratio [D _v ] of the volume average particle size [D _v ] to the number average particle size [D _n ] was [D _n ].
_v / D _n] is a 1.29, and the proportion of particles smaller than the particle size 5.0μm 9.8 number%, 8.0～12.7Myuemu
20.8% by number, the number of particles having a particle size of 16.0 μm or more is 3.3% by number, the volume average particle diameter [D _v ] is 7.8 μm, and flow type particles manufactured by Sysmex Co., Ltd. The circularity measured using an image analyzer "FPIA-2100" is 0.91, and using a dynamic viscoelasticity measuring device "MR-500" manufactured by UBM, a condition of a frequency of 1 Hz on a parallel plate. 1%, measured at 120 ° C below
Storage elastic modulus [G ' _1% ] at strain of 11.8 × 10 ³ P
a, Storage elastic modulus at 30% strain [G '30 _% ] is 7.0 × 1
0 ³ Pa and G'1 _% / G '30 _% were 1.7.

[0082]

[Table 1]

[0083]

According to the present invention, when an electrostatic latent image formed on a photosensitive layer of a photoconductor is developed with toner to form an image, an image having high image density and high quality can be formed at high speed. It is possible to provide an image forming method capable of performing the above.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of an image forming apparatus used in an image forming method of the present invention.

[Explanation of symbols]

1; photoconductor 1a; conductive support 1b; photosensitive layer 2; Charging device 3; Exposure device 4; Developing device 4a: developing roller 4b: toner supply roller 4c; blade 4d; agitator 5: Transfer device 6; Cleaning device 7: Fixing device 7a; lower fixing member 7b; upper fixing member 7c; heating device T: Toner P: Recording paper

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 9/087 G03G 15/00 303 15/00 303 9/08 381

Claims (5)

[Claims] 1. An electrostatic latent image formed on a photosensitive layer by exposing a cylindrical photosensitive body having a photosensitive layer on its outer peripheral surface at a constant peripheral speed while being uniformly charged and then exposed. When developing with toner to form an image, the ratio [d / v] of the outer peripheral length [d (mm)] from the charging position to the developing position of the photoconductor to the peripheral speed [v (mm / sec)] of the photoconductor (Seconds)] is 0.50 seconds or less to form an image, the toner particles are coated on their surfaces with an inorganic fine powder and an organic fine powder, and the inorganic fine powder species [N _I ] is 2 to 5
Species, a is 1 to 3 or organic fine powder species [N _O], the total weight of the end thereof of the inorganic fine powder with respect to 100 parts by weight of the toner particles [W _I], and the total weight of the powder organic fine [W
_O ], and the arithmetic mean particle diameter [D _I ] obtained by dividing the sum of the respective average particle diameters of the inorganic fine powder by N _I , and the arithmetic operation obtained by dividing the sum of the respective mean particle diameters of the organic fine powder by N _O. An image forming method, characterized in that the average particle diameter [D _O ] has a relationship of the following formulas (1), (2), and (3). 2.0 ≦ W _I ≦ 5.0 (1) 0.01 ≦ W _O ≦ 2.0 (2) 0.1 ≦ (D _O × W _O ) / (D _I × W _I ) ≦ 5 (3) 2. The image forming method according to claim 1, wherein the toner particles are composed of primary particle aggregates obtained by stirring and mixing polymer primary particles as a binder resin component in the presence of at least a colorant. . 3. The image forming method according to claim 1, wherein the toner particles contain waxes having a melting point of 50 to 100 ° C. 4. The toner has a circularity of 0.92 to 1.0 at a cumulative frequency of 50% of the circularity calculated by the following formula.
The image forming method according to claim 1, further comprising: Circularity = circumference of a circle having the same area as the area of the particle projection image / circumference of the particle projection image 5. The toner has a storage elastic modulus at 1% strain [G ′ _1% (Pa)] and a storage elastic modulus at 30% strain [G ′ _30% (G ′ _30% (in dynamic viscoelasticity measurement at 120 ° C. Pa)] has the relationship of the following formulas (4) and (5).
5. The image forming method according to any one of 4 to 4. 1.0 × 10 ² ≦ G ′ _1% ≦ 1.0 × 10 ⁴ (4) 1.0 ≦ G ′ _1% / G ′ _30% ≦ 10.0 (5)