JP2020144212A - Electrophotographic toner, two-component developer, toner storage unit, image forming apparatus, and image forming method - Google Patents

Abstract

To provide a large particle diameter toner that restricts scattering of toner and is excellent in suppliability.SOLUTION: An electrophotographic toner contains at least a binder resin and an external additive, and the toner satisfies requirements that (1) the volume average particle diameter (Dv) is 12 μm or more and 20 μm or less, and (2) the amount of extraction of silicone oil in the toner with chloroform is 60 ppm or more and 140 ppm or less with respect to the toner.SELECTED DRAWING: None

Description

The present invention relates to an electrophotographic toner, a two-component developer, a toner accommodating unit, an image forming apparatus, and an image forming method.

In recent years, surface processing by thick printing has become widespread for the purpose of increasing added value in the printing field.
As a means for realizing thick printing in electrophotographic, a means using a toner having a large particle size can be considered. However, when a large particle size toner is used, the amount of charge in the toner is low, so that the toner is likely to be scattered in the actual machine, and the density change of the toner is also large, so that the toner replenishment property is likely to be deteriorated.
As a means for controlling these, a method of adjusting the fluidity of the toner can be considered. In Patent Documents 1 to 5, the development stability and transfer stability in the actual machine are improved and the occurrence of photoconductor filming is suppressed by using the external additive treated with silicone oil.

An object of the present invention is to provide a large particle size toner which suppresses toner scattering and has excellent replenishability.

The above problem can be solved by the toner of the present invention having the following configuration.
A toner having at least a binder resin and an external additive, wherein the toner satisfies the following requirements (1) and (2).
(1) The volume average particle diameter (Dv) is 12 μm or more and 20 μm or less.
(2) The amount of silicone oil extracted with chloroform in the toner is 60 ppm or more and 140 ppm or less with respect to the toner.

It is possible to provide a large particle size toner that suppresses toner scattering and has excellent replenishability.

FIG. 1 is a schematic configuration diagram of an example of the image forming apparatus of the present invention.

The toner of the present invention is a toner having at least a binder resin and an external additive, and is characterized in that the toner satisfies the following requirements (1) and (2).
(1) The volume average particle diameter (Dv) is 12 μm or more and 20 μm or less.
(2) The amount of silicone oil extracted with chloroform in the toner is 60 ppm or more and 140 ppm or less with respect to the toner.
The volume average particle size (Dv) of the toner in the present invention means the volume average particle size (Dv) of the toner population particles.

Hereinafter, embodiments of the toner, the two-component developer, the toner accommodating unit, and the image forming apparatus of the present invention will be described in detail.

<Toner>
The toner of the present invention contains a matrix particle and an external additive.
The base particles contain a binder resin and, if necessary, other components.

<External agent>
It is preferable to contain silica treated with silicone oil as the external additive. Due to the presence of the silicone oil, the adhesive force between the toners can be improved and the scattering of the toner can be suppressed. Further, since the density change can be suppressed, the deterioration of the replenishability in the actual machine can be suppressed.
The amount of silicone oil in the toner can be calculated by extraction, but the amount extracted with chloroform is preferably 60 ppm or more and 140 ppm or less, and particularly preferably 100 ppm or more and 140 ppm or less. If the amount of silicone oil extracted is less than 60 ppm, it is not effective in suppressing toner scattering and improving replenishability. On the other hand, if it exceeds 140 ppm, the fluidity of the toner deteriorates remarkably, and the replenishability deteriorates.

As the external additive, silica that has not been treated with silicone oil may be contained, and can be appropriately selected depending on the intended purpose.
The external additive other than silica is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include inorganic particles.
The inorganic particles are not particularly limited and may be appropriately selected depending on the intended purpose. For example, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, fluorine compound, iron oxide, etc. Copper oxide, zinc oxide, tin oxide, silica sand, clay, mica, silica stone, silica soil, chromium oxide, cerium oxide, red iron oxide, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, Examples thereof include silicon carbonate and silicon nitride. These may be used alone or in combination of two or more. When two or more types are used in combination, it is preferable to select them so as to have resistance to development stress such as idling.
Among these, titanium oxide, strontium titanate, and alumina are preferable.

<Mother particles>
The matrix particles (also referred to as “toner matrix particles”) contain a binder resin and, if necessary, other components.
The volume average particle diameter (Dv) of the parent particles is preferably 12 μm or more and 20 μm or less, and particularly preferably 15 μm or more and 18 μm or less. If the volume average particle size is less than 12 μm, it becomes difficult to obtain a sufficient amount of adhesion, and as a result, the toner concentration becomes low, and it becomes difficult to obtain the effect of thick printing. Further, when the volume average particle diameter exceeds 20 μm, the toner scattering and the deterioration of the replenishability become remarkable, and the improvement by the combined use of silicone oil becomes small.
The solidification density of the parent particles is preferably 0.610 or less. When the compaction density is 0.610 or less, the change in toner density can be suppressed, and the replenishability can be improved.

<< Bundling resin >>
The binder resin is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a styrene resin (a homopolymer or copolymer containing styrene or a styrene substituent), a vinyl chloride resin, or styrene. / Vinyl acetate copolymer, rosin-modified maleic acid resin, phenol resin, epoxy resin, polyethylene resin, polypropylene resin, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene / ethyl acrylate copolymer, xylene resin, polyvinyl butyral Examples thereof include resins, petroleum-based resins, and hydrogenated petroleum-based resins.

Examples of the styrene resin (monopolymer or copolymer containing styrene or styrene substituent) include polystyrene, chloropolystyrene, polyα-methylstyrene, styrene / chlorostyrene copolymer, styrene / propylene copolymer, and styrene. / Butadiene copolymer, styrene / vinyl chloride copolymer, styrene / vinyl acetate copolymer, styrene / maleic acid copolymer, styrene / acrylic acid ester copolymer (styrene / methyl acrylate copolymer, styrene / Ethyl acrylate copolymer, styrene / butyl acrylate copolymer, styrene / octyl acrylate copolymer, styrene / phenyl acrylate copolymer, etc.), styrene / methacrylate copolymer (styrene / methyl methacrylate) Copolymer, styrene / ethyl methacrylate copolymer, styrene / butyl methacrylate copolymer, styrene / phenyl methacrylate copolymer, etc.), styrene / α-methyl chloroacrylate copolymer, styrene / acrylonitrile / acrylic Examples thereof include acid ester copolymers.
These may be used alone or in combination of two or more. Among these, polyester resin is preferable from the viewpoint of low temperature fixability and environmental safety (VOC due to residual monomer).

<<< Polyester resin >>
As the polyester resin, all commonly known polyester resins obtained by polycondensation reaction of alcohol and acid can be used.
Examples of the alcohol include diols, etherified bisphenols, divalent alcohol monomers in which these are substituted with saturated or unsaturated hydrocarbon groups having 3 to 22 carbon atoms, and trihydric or higher alcohol single amounts. The body etc. can be mentioned.

Examples of the diols include polyethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-propylene glycol, neopentyl glycol, 1,4-butenediol and the like. Can be mentioned.
Examples of the etherified bisphenols include 1,4-bis (hydroxymethyl) cyclohexane, bisphenol A, hydrogenated bisphenol A, polyoxyethylene bisphenol A, and polyoxypropylene bisphenol A.

Examples of the trihydric or higher alcohol monomer include sorbitol, 1,2,3,6-hexanetetrol, 1,4-salbitan, pentaesritol dipentaesritol, and tripentaesritol. , Citrus, 1,2,4-butantriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butantriol, trimethylolethane, trimethylolpropane, Examples thereof include 1,3,5-trihydroxymethylbenzene.
These may be used alone or in combination of two or more.

Examples of the carboxylic acid include monocarboxylic acids, divalent organic acid monomers, anhydrides of these acids, dimers of lower alkyl esters and linoleic acids, and trivalent or higher polyvalent carboxylic acid monomers. And so on.
Examples of the monocarboxylic acid include palmitic acid, stearic acid, and oleic acid.
Examples of the divalent organic acid monomer include maleic acid, fumaric acid, mesaconic acid, citraconic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebatic acid, and malonic acid, which have 3 carbon atoms. Examples thereof include those substituted with ~ 22 saturated or unsaturated hydrocarbon groups.

Examples of the trivalent or higher polyvalent carboxylic acid monomer include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2. , 4-Naphthalene tricarboxylic acid, 1,2,4-butane tricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxy-2-methyl-2-methylenecarboxypropane, tetra (methylenecarboxyl) methane , 1,2,7,8-octanetetracarboxylic acid embol trimeric acid, anhydrides of these acids and the like.
These may be used alone or in combination of two or more.

The method for producing the binder resin is not particularly limited and may be appropriately selected. For example, bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization and the like can be used.

<< Other ingredients >>
The other components are not particularly limited as long as they are used for ordinary toner, and can be appropriately selected depending on the intended purpose. For example, a colorant, a mold release agent, a trivalent or higher metal salt, and the like. Examples include wax dispersants.

<< Colorant >>
Examples of the colorant used for the toner of the present invention include carbon black, lamp black, iron black, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa yellow G, rhodamine 6C lake, calco oil blue, chrome yellow, quinacridone, and benzidine yellow. Conventionally known dyes and pigments such as dyes and pigments such as rosebengal and triallylmethane dyes can be used. These can be used alone or in combination, and can be used as a black toner or a full-color toner.
The content of these colorants is preferably 1% by mass to 30% by mass, more preferably 3% by mass to 20% by mass, based on the binder resin component of the toner.

<< Metal salt of trivalent or higher >>
The toner of the present invention preferably contains a trivalent or higher valent metal salt. By containing the metal salt, a cross-linking reaction with the acidic group of the binder resin proceeds at the time of fixing to form a weak three-dimensional cross-link, thereby obtaining high-temperature offset resistance while maintaining low-temperature fixability. Can be done.
As the metal salt, for example, at least one selected from a metal salt of a salicylic acid derivative and an acetylacetonate metal salt is preferable. The metal is not particularly limited as long as it is a trivalent or higher valent ion metal, and examples thereof include iron, zirconium, aluminum, titanium, and nickel.
As the trivalent or higher metal salt, a trivalent or higher salicylic acid metal compound is preferable.
The content of the metal salt is, for example, preferably 0.5 to 2 parts by mass, and more preferably 0.5 to 1 part by mass with respect to 100 parts by mass of the toner. When the content is 0.5 parts by mass to 2 parts by mass, the following problems can be prevented.
・ Defects with poor hot offset resistance ・ Defects with poor gloss and low temperature fixability

<< Release agent >>
The toner of the present invention preferably contains an ester wax as a release agent. Since the ester wax has low compatibility with a general polyester binder resin, it easily exudes to the surface at the time of fixing, exhibits high releasability, and can secure high low temperature fixability.

Further, the ester wax is preferably 4 parts by mass to 8 parts by mass, and more preferably 5 parts by mass to 7 parts by mass with respect to 100 parts by mass of the toner. If the content is less than 4 parts by mass, the exudation to the surface at the time of fixing is insufficient, the releasability is deteriorated, and the low temperature fixing property and the high temperature offset resistance are lowered. When the content is more than 8 parts by mass, the amount of the release agent deposited on the surface of the toner increases, the storage stability as the toner is lowered, and the filming property to the photoconductor or the like is lowered.

As the ester wax, it is preferable to use a synthetic monoester wax. Examples of synthetic monoester waxes include monoester waxes synthesized from long-chain linear saturated fatty acids and long-chain linear saturated alcohols. The long-chain linear saturated fatty acid is represented by the general formula C _n H _{2n + 1} COOH, and is preferably about n = 5 to 30, and more preferably n = 13 to 29. The long-chain linear saturated alcohol is represented by CnH2n + 1OH, preferably about n = 5 to 30, and more preferably n = 14 to 30.

Specific examples of long-chain linear saturated fatty acids include capric acid, undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecanoic acid, palmitic acid, heptadecanoic acid, tetradecanoic acid, stearic acid, nonadecanic acid, and aramonic acid. Examples thereof include behenic acid, lignoceric acid, cerotic acid, heptacosanoic acid, montanic acid and melissic acid. On the other hand, specific examples of long-chain linear saturated alcohols include amyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, capryl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, lauryl alcohol, tridecyl alcohol, and myristyl alcohol. Examples thereof include pentadecyl alcohol, cetyl alcohol, heptadecyl alcohol, stearyl alcohol, nonadecil alcohol, eikosyl alcohol, ceryl alcohol and heptadecanool, which have substituents such as lower alkyl group, amino group and halogen. You may.

（前記一般式（１）中、Ｒ_１及びＲ_２は、エチレン基、プロピレン基等の炭素数２〜４のアルキレン基である。Ｒ_３及びＲ_４は、水素原子、炭素数１〜６の直鎖アルキル基、又は分岐状アルキル基であり、例えば、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、ｔ−ブチル基、ヘキシル基、などが挙げられる。また、ｘ及びｙは、正の整数であり、その和は１〜１６、特に好ましくは２〜６である。）
なお、アルコール成分には、芳香族アルコール成分以外の多価アルコールが含まれていてもよい。 << Wax Dispersant >>
The toner of the present invention preferably contains a wax dispersant, and the wax dispersant is polycondensed as a monomer containing at least an aromatic alcohol component and a carboxylic acid component having an aliphatic dicarboxylic acid having 9 or more and 14 or less carbon atoms. More preferably, it is a hybrid resin in which a styrene resin component and a styrene resin component containing styrene, acrylic acid and an acrylic acid derivative are bonded.
Here, the aromatic alcohol component is preferably one represented by the following general formula (1).

(In the general formula (1), R ₁ and R ₂ are alkylene groups having 2 to 4 carbon atoms such as an ethylene group and a propylene group. R ₃ and R ₄ are hydrogen atoms and carbon atoms 1 to 6. It is a linear alkyl group or a branched alkyl group, and examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a t-butyl group, a hexyl group, and the like. It is a positive integer, the sum of which is 1-16, particularly preferably 2-6.)
The alcohol component may contain a polyhydric alcohol other than the aromatic alcohol component.

The carboxylic acid component having an aliphatic dicarboxylic acid having 9 or more and 14 or less carbon atoms is preferably a linear alkanedicarboxylic acid, and examples thereof include azelaic acid, sebacic acid, dodecanedioic acid, and tetradecanedioic acid. The carboxylic acid component may contain a polyvalent carboxylic acid compound other than the carboxylic acid component having an aliphatic dicarboxylic acid having 9 or more and 14 or less carbon atoms, and oxalic acid, malonic acid, maleic acid, and fumal. An aliphatic dicarboxylic acid such as an acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, succinic acid substituted with an alkyl group having 1 to 30 carbon atoms or an alkenyl group having 2 to 30 carbon atoms, Aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, trimellitic acid, 2,5,7-naphthalene tricarboxylic acid, pyromellitic acid and other trivalent or higher aromatics Examples thereof include group carboxylic acids, acid anhydrides thereof, and alkyl esters having 1 or more and 3 or less carbon atoms.

Compared with the polyester resin used as the binder resin for the toner of the present invention, the hybrid resin has good compatibility with general wax, so that the dispersed state of the wax tends to be small. In addition, the hybrid resin has a weak internal cohesive force and is superior in pulverizability to the polyester resin. Therefore, even if the wax dispersion state is the same, the probability that the interface between the wax and the resin becomes a crushed surface is low as in the case of polyester resin, and the wax existing on the surface of the toner particles can be suppressed, so that the toner can be used as a toner. Heat-resistant storage stability can be improved.
Further, the hybrid resin tends to have properties close to those of polyester, and does not significantly impair the low temperature fixability and internal cohesive force of polyester.

The wax dispersant is preferably contained in an amount of 8 parts by mass or less with respect to 100 parts by mass of the toner. By containing the wax dispersant, the effect of dispersing the wax can be obtained, and stable improvement in heat-resistant storage stability can be expected regardless of the manufacturing method. In addition, the wax diameter becomes smaller due to the dispersion effect of the wax, and the filming phenomenon on the photoconductor or the like can be suppressed. When the content of the wax dispersant is more than 8 parts by mass, the amount of incompatible components with respect to the polyester resin increases and the dispersibility of the wax becomes too high, so that the filming resistance is improved, but the wax at the time of fixing The exudation to the surface is deteriorated, and the low temperature fixability and hot offset resistance are deteriorated.

<Developer>
The developer of the present invention contains at least the toner and, if necessary, other components such as carriers which are appropriately selected.
Therefore, it is possible to stably form a high-quality image with excellent transferability and chargeability. The developer may be a one-component developer or a two-component developer, but when used in a high-speed printer or the like corresponding to an improvement in information processing speed in recent years, the life of the developer may be long. A two-component developer is preferable because it improves.
The carrier can be appropriately selected depending on the intended purpose, and examples thereof include a magnetic carrier and a resin carrier.

The magnetic carrier is preferably magnetic fine particles. Examples of the magnetic fine particles include spinel ferrites such as magnetite and gamma iron oxide; spinel ferrites containing one or more metals other than iron (Mn, Ni, Zn, Mg, Cu, etc.); barium ferrites and the like. Magnetoplanbite type ferrite; iron or alloy particles having an oxide layer on the surface can be mentioned. Among these, ferromagnetic fine particles such as iron are preferable when high magnetization is particularly required.

The shape of the carrier may be granular, spherical, or needle-shaped. Further, in consideration of chemical stability, it is preferable to use magnetoplumbite-type ferrite such as spinel ferrite containing magnetite and gamma iron oxide and barium ferrite. A resin carrier having a desired magnetization can also be used by selecting the type and content of the ferromagnetic fine particles. The magnetic property of the carrier at this time is preferably 30 to 150 emu / g at a magnetization strength of 1,000 oersted.

Such a resin carrier can be produced by spraying a melt-kneaded product of magnetic fine particles and an insulating binder resin with a spray dryer. Specifically, by reacting and curing a monomer or a prepolymer in an aqueous medium in the presence of magnetic fine particles, a resin carrier in which magnetic fine particles are dispersed in a condensed binder can be produced.

The chargeability can be controlled by fixing positively or negatively charged fine particles or conductive fine particles on the surface of the magnetic carrier, or by coating with a resin.
Silicone resin, acrylic resin, epoxy resin, and fluororesin are used as the surface coating material, and positive or negatively charged fine particles or conductive fine particles can be included in the coating, but the silicone resin and acrylic resin can be used. preferable.
The mixing ratio of the electrophotographic toner of the present invention and the magnetic carrier is preferably 2% by mass to 10% by mass as the toner concentration.

When the volume average particle diameter (Dv) of the toner in the present invention is Dt and the volume average particle diameter (Dv) of the carrier is Dc, the particle diameter ratio Dc / Dt is preferably 3.0 or more. When Dc / Dt is 3.0 or more, the amount of charge does not become excessive, and a sufficient amount of toner adhering to the image can be obtained.

<Toner storage unit>
The toner accommodating unit in the present invention means a unit accommodating toner in a unit having a function of accommodating toner. Here, examples of the toner storage unit include a toner storage container, a developing device, and a process cartridge.
The toner containing container means a container containing toner.
A developer has a means for accommodating and developing toner.
The process cartridge is a cartridge in which at least an electrostatic latent image carrier (also referred to as an image carrier) and a developing means are integrated, accommodates toner, and is detachable from an image forming apparatus. The process cartridge may further include at least one selected from charging means, exposing means, and cleaning means.

By mounting the toner accommodating unit of the present invention on an image forming apparatus to form an image, external addition on the photoconductor can be used not only in normal temperature and humidity but also in a low temperature and low humidity environment for a long period of time. Taking advantage of the characteristics of the toner, which does not generate abnormal images due to filming by the agent and can stably secure a high image density, it has long-term image stability and forms high-quality, high-definition images. can do.

<Image forming device and image forming method>
The image forming apparatus of the present invention has at least an electrostatic latent image carrier, an electrostatic latent image forming means, and a developing means, and further has other means, if necessary.
The image forming method according to the present invention includes at least an electrostatic latent image forming step and a developing step, and further includes other steps if necessary.
The image forming method can be suitably performed by the image forming apparatus, the electrostatic latent image forming step can be preferably performed by the electrostatic latent image forming means, and the developing step is the developing means. The other steps can be more preferably performed by the other means.

The image forming apparatus of the present invention more preferably includes an electrostatic latent image carrier, an electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, and the electrostatic latent image carrying. A developing means provided with toner, which develops the electrostatic latent image formed on the body with toner to form a toner image, and a toner image formed on the electrostatic latent image carrier are recorded on a recording medium. It includes a transfer means for transferring to the surface and a fixing means for fixing the toner image transferred to the surface of the recording medium.
Further, the image forming method of the present invention more preferably includes an electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier, and the said one formed on the electrostatic latent image carrier. A developing step of developing an electrostatic latent image with toner to form a toner image, a transfer step of transferring the toner image formed on the electrostatic latent image carrier to the surface of a recording medium, and the recording. It includes a fixing step of fixing the toner image transferred to the surface of the medium.

The toner is used in the developing means and the developing process. Preferably, the toner image is formed by using a developer containing the toner and, if necessary, other components such as carriers.

<Electrostatic latent image carrier>
The material, structure, and size of the electrostatic latent image carrier (hereinafter, also referred to as “photoreceptor”) are not particularly limited and may be appropriately selected from known materials. , Inorganic photoconductors such as amorphous silicon and selenium, and organic photoconductors such as polysilane and phthalopolymethine.

<Electrostatic latent image forming means>
The electrostatic latent image forming means is not particularly limited as long as it is a means for forming an electrostatic latent image on the electrostatic latent image carrier, and can be appropriately selected depending on the intended purpose. Examples thereof include a means having at least a charging member for charging the surface of the electrostatic latent image carrier and an exposure member for exposing the surface of the electrostatic latent image carrier in an image manner.

<Development means>
The developing means is not particularly limited as long as it is a developing means including toner that develops the electrostatic latent image formed on the electrostatic latent image carrier to form a visible image, depending on the purpose. Can be selected as appropriate.

<Other means>
Examples of the other means include transfer means, fixing means, cleaning means, static elimination means, recycling means, control means and the like.

The image forming apparatus of the present invention preferably does not have a lubricant applying means. The lubricant applying means is a means for applying a lubricant to a photoconductor.
The lubricant refers to a lubricant applied to the surface of a photoconductor or the like. Examples of the lubricant include zinc stearate and the like.

The purpose of applying the lubricant is, for example, as follows.
-By lowering the friction coefficient μ, the behavior of the cleaning blade edge is stabilized and the cleaning means is assisted.
-Protects the surface of the photoconductor from the charging current when an AC voltage is applied to the charging roller.
-By scraping the lubricant applied to the surface of the image carrier, etc. using a cleaning blade, it is possible to suppress the adhesion of toner components to the image carrier, etc., and the contamination by external additives, paper particles, etc.

As a method of applying the lubricant, for example, there is a method of applying the lubricant to the surface of the image carrier with a brush roller, and the lubricant solid body, which is a mass of the lubricant, is scratched with a coating brush to obtain the lubricant and is applied to the surface of the image carrier. be able to.
In general, in an image forming apparatus excluding the lubricant applying means, the behavior of the cleaning blade edge is not stable, which causes cleaning failure, and the cleaning blade is in direct contact with an image carrier or the like, so that surface wear increases. ..
However, in the present invention, since the dysplasia of the external additive is high, the above-mentioned cleaning failure is unlikely to occur.

Next, one aspect of carrying out the method of forming an image by the image forming apparatus of the present invention will be described with reference to FIG.
FIG. 1 is a schematic configuration diagram of an example of the image forming apparatus. Around the photoconductor drum (hereinafter referred to as a photoconductor) 110 as an image carrier, a charging roller 120 as a charging device, an exposure device 130, a cleaning device 160 having a cleaning blade, a static elimination lamp 170 as a static elimination device, and development The apparatus 140 and the intermediate transfer body 150 as the intermediate transfer body are arranged. The intermediate transfer body 150 is suspended by a plurality of suspension rollers 151, and is configured to travel in an endless manner in the direction of an arrow by a driving means such as a motor (not shown). A part of the suspension roller 151 also serves as a transfer bias roller that supplies a transfer bias to the intermediate transfer body, and a predetermined transfer bias voltage is applied from a power source (not shown). A cleaning device 190 having a cleaning blade for the intermediate transfer body 150 is also provided. Further, a transfer roller 180 is arranged as a transfer means for transferring the developed image to the transfer paper 1100 as the final transfer material facing the intermediate transfer body 150, and the transfer roller 180 applies a transfer bias by a power supply device (not shown). Be supplied. A corona charger 152 as a charge applying means is provided around the intermediate transfer body 150.

The developing apparatus 140 includes a developing belt 141 as a developing agent carrier, a black (hereinafter referred to as Bk) developing unit 145K, a yellow (hereinafter referred to as Y) developing unit 145Y, and magenta (hereinafter referred to as magenta) arranged around the developing belt 141. It is composed of a developing unit (called magenta) 145M and a cyan (hereinafter referred to as C) developing unit 145C. Further, the developing belt 141 is stretched over a plurality of belt rollers and is configured to travel in an endless manner in the direction of the arrow by a driving means such as a motor (not shown), and the developing belt 141 and the photoconductor 110 are in contact with the photoconductor 110. It moves at almost the same speed.

Since the configuration of each development unit is common, the following description is given only for the Bk development unit 45K, and for the other development units 145Y, 145M, and 145C, the parts corresponding to those in the Bk development unit 145K in the drawing are described. Y, M, and C are added after the numbers assigned to those in the unit, and the description thereof will be omitted. The Bk developing unit 145K is arranged so that a developing tank 142K containing a high-viscosity and high-concentration liquid developer containing toner particles and a carrier liquid component and a lower portion thereof are immersed in the liquid developer in the developing tank 142K. It is composed of a pumping roller 143K and a coating roller 144K in which the developer pumped from the pumping roller 143K is thinned and applied to the developing belt 141. The coating roller 144K has conductivity, and a predetermined bias is applied from a power source (not shown).

Subsequently, the operation of the image forming apparatus according to the present embodiment will be described.
In FIG. 1, the photoconductor 110 is uniformly charged by the charging roller 120 while being rotationally driven in the direction of the arrow, and then the reflected light from the document is image-projected onto the photoconductor 110 by an optical system (not shown) by the exposure apparatus 130. Form an electrostatic latent image. This electrostatic latent image is developed by the developing device 140 to form a toner image as a manifest image. The developer layer on the developing belt 141 is peeled off from the developing belt 141 in a thin layer state by contact with the photoconductor in the developing region, and shifts to a portion on the photoconductor 110 where a latent image is formed. The toner image developed by the developing device 140 is transferred to the surface of the intermediate transfer body 150 at the contact portion (primary transfer region) between the photoconductor 110 and the intermediate transfer body 150 moving at a constant velocity (primary). Transcription). When performing transfer in which three colors or four colors are superimposed, this step is repeated for each color to form a color image on the intermediate transfer body 150.

The corona charger 152 for applying an electric charge to the superimposed toner image on the intermediate transfer body is installed on the downstream side of the contact-opposing portion between the photoconductor 110 and the intermediate transfer body 150 in the rotation direction of the intermediate transfer body 150. It is installed at a position on the upstream side of the contact-opposing portion between the intermediate transfer body 150 and the transfer paper 1100. Then, the corona charger 152 imparts a true electric charge to the toner image having the same polarity as the charging polarity of the toner particles forming the toner image, and the electric charge is sufficient for good transfer to the transfer paper 1100. To the toner image. After being charged by the corona charger 152, the toner image is collectively transferred onto the transfer paper 1100 conveyed in the direction of the arrow from the paper feed section (not shown) by the transfer bias from the transfer roller 180 (secondary transfer). .. After that, the transfer paper 1100 to which the toner image is transferred is separated from the photoconductor 110 by a separating device (not shown), fixed by a fixing device (not shown), and then discharged from the device. On the other hand, in the photoconductor 110 after transfer, the untransferred toner is collected and removed by the cleaning device 160, and the residual charge is removed by the static elimination lamp 170 in preparation for the next charging. A color image is usually formed of four colored toners. One to four toner layers are formed in one color image. The toner layer passes through primary transfer (transfer from the photoconductor to the intermediate transfer belt) and secondary transfer (transfer from the intermediate transfer belt to the sheet).

Although the present invention relates to the toner for electrophotographic described in <1> below, the following <2> to <10> are included as embodiments of the invention.
<1> A toner having at least a binder resin and an external additive, wherein the toner satisfies the following requirements (1) and (2).
(1) The volume average particle diameter (Dv) is 12 μm or more and 20 μm or less.
(2) The amount of silicone oil extracted with chloroform in the toner is 60 ppm or more and 140 ppm or less with respect to the toner.
<2> The electrophotographic toner according to <1> above, which has a compaction density of 0.610 (g / cm ³ ) or less.
<3> The electrophotographic toner according to <1> or <2> above, wherein the volume average particle diameter (Dv) of the toner is 15 μm or more and 18 μm or less.
<4> The electrophotographic toner according to any one of <1> to <3>, wherein the amount of the silicone oil extracted with chloroform in the toner is 100 ppm or more and 140 ppm or less with respect to the toner.
<5> The electrophotographic toner according to any one of <1> to <4> above, wherein the toner contains silica treated with silicone oil as an external additive.
<6> A two-component developer containing the toner and a carrier according to any one of <1> to <5> above, wherein the volume average particle diameter (Dv) of the toner is Dt, and the carrier. A two-component developer having a particle size ratio Dc / Dt of 3.0 or more when the volume average particle size (Dv) is Dc.
<7> A toner storage unit containing the toner according to any one of <1> to <5> above.
<8> Electrostatic latent image carrier and
An electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier,
A developing means including toner, which develops the electrostatic latent image formed on the electrostatic latent image carrier with toner to form a toner image.
A transfer means for transferring the toner image formed on the electrostatic latent image carrier to the surface of the recording medium, and
A fixing means for fixing the toner image transferred to the surface of the recording medium is included.
An image forming apparatus, wherein the toner is the toner according to any one of <1> to <5>.
<9> The image forming apparatus according to <8>, wherein the image forming apparatus does not have a mechanism for applying a lubricant on the photoconductor drum.
<10> An electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier,
A developing step of developing the electrostatic latent image formed on the electrostatic latent image carrier with toner to form a toner image, and
A transfer step of transferring the toner image formed on the electrostatic latent image carrier to the surface of the recording medium, and
Including a fixing step of fixing the toner image transferred to the surface of the recording medium.
An image forming method, wherein the toner is the toner according to any one of <1> to <5>.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. However, "part" represents "mass part" unless otherwise specified.

<Measurement of toner volume average particle size>
The toner volume average particle size is measured as follows.
First, 0.1 to 5 ml of a surfactant (preferably alkylbenzene sulfonate) was added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution.
Here, the electrolytic solution is a solution prepared by preparing an approximately 1% NaCl aqueous solution using primary sodium chloride, and for example, ISOTON-II (manufactured by Coulter) can be used.
Here, 2 to 20 mg of the measurement sample is further added.
The electrolytic solution in which the sample is suspended is dispersed with an ultrasonic disperser for about 1 to 3 minutes, and the weight and number of toner particles or toners are measured with a Coulter Multisizer II using a 100 μm aperture as an aperture. , Volume distribution and number distribution were calculated.
From the obtained distribution, the volume average particle size and the number average particle size of the toner were obtained.
The channels are: 2.00 to less than 2.52 μm; 2.52 to less than 3.17 μm; 3.17 to less than 4.00 μm; 4.0 to less than 5.04 μm; 5.04 to less than 6.35 μm; 6 .35 to less than 8.00 μm; 8.00 to less than 10.08 μm; 10.08 to less than 12.70 μm; 12.70 to less than 16.00 μm; 16.0 to less than 20.20 μm; 20.20 to 25. Less than 40 μm; 25.40 to less than 32.00 μm; 13 channels less than 32.00 to 40.30 μm were used, and particles having a particle size of 2.00 μm or more and less than 40.30 μm were targeted.

<Measurement of toner compaction density>
The hardening density (g / cm ³ ) of the toner is such that a cylindrical container with a diameter of 5.03 cm, a height of 5.03 cm, and a volume of 100 cm ³ is fitted with a cylindrical cap, powder is added to the upper edge, and the tap height is 1. 0.8 cm tapping is performed 180 times. After completion, the measurement was performed by removing the cap, scraping the powder on the upper surface of the container and weighing it.

<Measurement of silicone oil amount in toner>
The amount of free silicone oil (silicone oil free amount) in the toner was measured by a quantification method consisting of the following procedures (1) to (3).
(1) Extraction of free silicone oil The toner of the sample was immersed in chloroform, stirred and left to stand.
Chloroform was newly added to the solid content after removing the supernatant by centrifugation, and the mixture was stirred and left to stand.
This operation was repeated to remove free silicone oil from the sample.
(2) Quantification of carbon content The quantification of the carbon content in the sample from which the free silicone oil was removed was measured with a CHN elemental analyzer (CHN coder MT-5 type (manufactured by Yanako)).
(3) Quantification of the amount of silicone oil released The amount of silicone oil released (mass%) was calculated by the following formula (1).
Silicone oil release amount = (C0-C1) / C × 100 × 37/12 ・ ・ ・ (1)
C, C0, C1, and the coefficient 37/12 in the above equation (1) represent the following values and meanings.
C: Carbon content in the treatment agent silicone oil (mass%)
C0: Carbon content (mass%) in the sample before the extraction operation
C1: Carbon content (mass%) in the sample after the extraction operation
Coefficient 37/12: Conversion coefficient from the amount of C in the structure of polydimethylsiloxane to the total amount

<Manufacturing example>
<< Manufacturing of polyester resin >>
258 parts of bisphenol A propylene oxide 2 mol adduct, 1,344 parts of bisphenol A ethylene oxide 2 mol adduct, 800 parts terephthalic acid, and a condensation catalyst in a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube. 1.8 parts of tetrabutoxytitanate was added, and the mixture was reacted at 230 ° C. for 6 hours while distilling off the generated water under a nitrogen stream. Next, the reaction was carried out under a reduced pressure of 5 mmHg to 20 mmHg for 1 hour, cooled to 180 ° C., 10 parts of trimellitic anhydride was added, and under a reduced pressure of 5 mmHg to 20 mmHg, the weight average molecular weight was 30,000 and the number average molecular weight was several. Was reacted until the amount reached 2,300 to obtain a polyester resin.

<< Manufacture of monoester wax >>
In a 1-liter four-necked flask equipped with a thermometer, a nitrogen introduction tube, a stirrer and a cooling tube, 50 parts of cerotic acid as a fatty acid component, 50 parts of palmitic acid, and 100 parts of ceryl alcohol as an alcohol component are added. The reaction product was distilled off at 220 ° C. under a nitrogen stream, and the reaction was carried out at normal pressure for 15 hours or more to obtain a monoester wax having a melting point of 70.5 ° C.

<< Manufacture of toner matrix particles >>
(Manufacturing Example 1)
-Polyester resin (Mw: 30,000, Mn: 2,300) 90.0 parts-Styrene acrylic copolymer (EXD-001 manufactured by Sanyo Kasei Co., Ltd.) 5.0 parts (Tg68 ° C, Mw13,000)
・ Monoester wax (mp70.5 ℃) 5.0 parts ・ Salicylic acid derivative zirconium salt 0.9 parts (Product name: TN-105, Manufacturing company name: Hodogaya Chemical Co., Ltd.)
The above toner raw materials are premixed using a Henshell mixer (FM20B manufactured by Nippon Coke Industries Co., Ltd.), and then melted at a temperature of 100 ° C. to 130 ° C. using a uniaxial kneader (Buss, Conida kneader). Kneaded. The obtained kneaded product was cooled to room temperature and then roughly pulverized to 200 μm to 300 μm in Rohtoplex. Next, using a counter jet mill (manufactured by Hosokawa Micron Co., Ltd., 100 AFG), fine pulverization was performed while appropriately adjusting the pulverized air pressure so that the weight average particle size was 15.4 ± 0.3 μm, and then an air flow classifier (100 AFG). EJ-LABO manufactured by Matsubo Co., Ltd.) appropriately adjusts the louver opening so that the volume average particle size is 16.0 ± 0.4 μm and the volume average particle size / number average particle size ratio is 1.25 or less. While classifying, toner matrix particles A were obtained.

(Manufacturing Example 2)
In Production Example 1, the volume average particle size was 12.0 ± 0.4 μm and the volume average particle size / number average particle size ratio was 1.25 or less by the same procedure except that the fine pulverization and classification conditions were changed. Toner matrix particles B were obtained.

(Manufacturing Example 3)
In Production Example 1, the volume average particle size was 19.0 ± 0.4 μm and the volume average particle size / number average particle size ratio was 1.25 or less by the same procedure except that the fine pulverization and classification conditions were changed. Toner matrix particles C were obtained.

(Manufacturing Example 4)
In Production Example 1, the volume average particle size was 10.0 ± 0.4 μm and the volume average particle size / number average particle size ratio was 1.25 or less by the same procedure except that the fine pulverization and classification conditions were changed. Toner matrix particles D were obtained.

(Manufacturing Example 5)
In Production Example 1, the volume average particle size was 22.0 ± 0.4 μm and the volume average particle size / number average particle size ratio was 1.25 or less by the same procedure except that the fine pulverization and classification conditions were changed. Toner matrix particles E were obtained.

(Manufacturing Example 6)
・ Silicone resin (organo straight silicone) 100 parts ・ Toluene 100 parts ・ γ- (2-aminoethyl) aminopropyltrimethoxysilane 5 parts ・ Carbon black 10 parts Disperse the above mixture with a homomixer for 20 minutes and coat layer. A forming solution was prepared. This coating layer forming liquid was applied to a spherical ferrite surface having an average particle size of 55 μm so that the average film thickness was 0.20 μm using a fluidized bed coating device to form an internal resin layer. Using a fluidized bed coating device, the temperature inside the fluidized bed was controlled to 70 ° C. for coating and drying. The obtained carrier was fired in an electric furnace at 180 ° C. for 2 hours, and then the particle size was adjusted by sieving to obtain a carrier A having a volume average particle diameter of 55 μm.

(Manufacturing Example 7)
In Production Example 6, a carrier B having a volume average particle diameter of 35 μm was obtained by the same procedure as in Production Example 6 except that spherical ferrite having an average particle diameter of 35 μm was used.

<< Manufacture of toner >>
(Example 1)
Manufacture of Toner 1 (Manufacture of Toner 1 for Examples 1A and 1B shown in Table 3)
RY-300 (Aerosil: 0.75 parts) and RY-50 (Aerosil: 0.35 parts) are added to 100 parts of toner matrix particles A, and a Henschel mixer (FM20C / made by Nippon Coke Industries Co., Ltd.) Toner 1 was obtained by repeating rotation 1 min and stop 1 min 16 times at a rotation speed of 3,176 rpm using I).

(Example 2)
Production of Toner 2 Toner 2 was obtained by the same procedure except that RY-300 (manufactured by Aerosil: 0.65 parts) and RY-50 (manufactured by Aerosil: 0.30 parts) were used in the production of toner 1.

(Example 3)
Production of Toner 3 Toner 3 was obtained by the same procedure except that RY-300 (manufactured by Aerosil: 0.50 parts) and RY-50 (manufactured by Aerosil: 0.25 parts) were used in the production of toner 1.

(Example 4)
Production of Toner 4 Toner 4 was obtained by the same procedure except that RY-300 (manufactured by Aerosil: 0.40 parts) and RY-50 (manufactured by Aerosil: 0.20 parts) were used in the production of toner 1.

(Example 5)
Manufacture of Toner 5 In the manufacture of toner 1, the procedure is the same except that toner matrix particles B are used and RY-300 (Aerosil: 0.75 parts) and RY-50 (Aerosil: 0.35 parts). Toner 5 was obtained.

(Example 6)
Manufacture of Toner 6 In the manufacture of toner 1, the procedure is the same except that toner matrix particles C are used and RY-300 (Aerosil: 0.75 parts) and RY-50 (Aerosil: 0.35 parts). Toner 6 was obtained.

(Example 7)
Manufacture of toner 7)
Toner 7 was obtained by the same procedure except that RY-300 (manufactured by Aerosil: 0.80 parts) and RY-50 (manufactured by Aerosil: 0.45 parts) were used in the production of toner 1.

(Comparative Example 1)
Production of Toner 8 Toner 8 was obtained by the same procedure except that RY-300 (manufactured by Aerosil: 0.90 parts) and RY-50 (manufactured by Aerosil: 0.45 parts) were used in the production of toner 1.

(Comparative Example 2)
Production of Toner 9 Toner 9 was obtained by the same procedure except that RY-300 (manufactured by Aerosil: 0.30 parts) and RY-50 (manufactured by Aerosil: 0.15 parts) were used in the production of toner 1.

(Comparative Example 3)
Production of Toner 10 In the production of toner 1, the procedure is the same except that the toner matrix particles D are used and RY-300 (Aerosil: 0.75 parts) and RY-50 (Aerosil: 0.35 parts). Toner 10 was obtained.

(Comparative Example 4)
Manufacture of Toner 11 In the manufacture of toner 1, the procedure is the same except that the toner matrix particles E are used and RY-300 (Aerosil: 0.75 parts) and RY-50 (Aerosil: 0.35 parts). Toner 11 was obtained.

(Comparative Example 5)
Production of Toner 12 Toner 12 was obtained by the same procedure except that RY-300 (manufactured by Aerosil: 0.83 parts) and RY-50 (manufactured by Aerosil: 0.45 parts) were used in the production of toner 1.

<< Manufacture of 2-component developer >>
(Manufacturing of developer 1)
Carrier A and toner 1 were uniformly mixed and charged at 48 rpm for 5 minutes using a turbobler mixer (manufactured by Willie et Bacoffen (WAB)) to prepare a developer 1. The mixing ratio of the toner and the carrier was adjusted to the toner concentration of the initial developer of the evaluator: 4% by mass.

(Manufacturing of developers 2 to 13)
In the production of the developing agent 1, the developing agents 2 to 13 were produced by the same procedure except that the type of toner or the type of carrier was changed as shown in Table 2 below.

Toner scattering property, toner replenishing property, and image density were evaluated using the above-mentioned developers 1 to 13.
The evaluation method is shown below, and the evaluation results are shown in Table 3.

<Toner scattering property>
A dust amount measuring device (for example, a laser dust monitor (manufactured by Hitachi Electronics Engineering Co., Ltd.)) is installed in advance in the downstream part of the developing area in the image forming apparatus, and a 5% image density chart is output to measure scattered toner after copying. The actual weight value of was measured.
Based on this, the overall toner scattering amount level was evaluated on a scale of ⊚, ◯, Δ, and ×. In the evaluation, ◎, ○, and △ were judged to be acceptable, and × was judged to be unacceptable.
⊚: When there is almost no toner scattering ○: When there is little toner scattering △: When there is but not much toner scattering ×: When there is a lot of toner scattering and it becomes a problem

<Toner replenishment>
120 g of toner was filled in the toner container (the capacity of the toner container is 1,200 mL). The toner container was shaken to sufficiently stir the toner. The toner storage container was attached to a replenishment device equipped with a transfer nozzle. The amount of toner discharged from the replenishment device was measured by rotating the toner storage container and operating the replenishment device.
Condition: Toner container rotation speed: 100 rpm
Transfer screw pitch in the transfer nozzle of the replenishment device: 12.5 mm
Transport screw outer diameter: 10 mm
Transport screw shaft diameter: 4 mm
Transport screw rotation speed: 500 rpm
The toner replenishability from the container body at that time was evaluated according to the following evaluation criteria.
◎, ○, and △ were accepted, and × was rejected.

〔Evaluation criteria〕
⊚: Very good (when the drive is continued until the toner cannot be discharged, the amount of toner replenished is 0.4 g / sec or more in the range where the remaining amount of toner in the toner container is less than 70 g and 10 g or more. Stable (constant amount) is maintained.)
* The toner replenishment amount of 0.4 g / sec is a replenishment amount that is predicted to have no blurring of the solid image due to insufficient toner replenishment amount (solid followability) even if all solid images are continuously passed on A4 paper. ..
* The range of 10 g or more of toner is taken into consideration for the amount of toner adhering to the inner wall of the container.
◯: Good (when the drive is continued until the toner cannot be discharged, the remaining amount of toner in the toner container is less than 70 g, and the amount of toner replenished is less than 0.4 g / sec in the range of 10 g or more. It is maintained at.)
* The toner replenishment amount is less than 0.4 g / sec, but since the replenishment amount is maintained stably (at a constant amount), the toner replenishment amount is raised by increasing the rotation speed of the toner storage container. It is possible, stable, and sufficient replenishment can be performed for solid tracking.
Δ: Allowable level (Toner is discharged after the remaining amount of toner in the toner container becomes less than 70 g when the drive is continued until the toner cannot be discharged, but the amount of toner replenished is not constant. , Decreasing with inclination.)
* Since toner is discharged, replenishment does not become 0, but more complicated replenishment control is required to ensure solid followability.
X: A level that cannot be used practically (when the drive is continued until the toner cannot be discharged, the toner is discharged, but the toner is not discharged when the remaining amount of toner is 70 g or more).

<Image density>
The image density (ID) of the 5% density chart discharged in the above scattering property evaluation was measured by X-rite, and the average value of 5 sheets was calculated.
◎, 〇, △ were accepted, and × was rejected.
〔Evaluation criteria〕
⊚: ID is 1.8 or more and 〇: ID is 1.4 or more and less than 1.8 Δ: ID is 1.0 or more and less than 1.4 ×: ID is less than 1.0 Evaluation result when each developer is used Is as shown in Table 2.

Japanese Patent No. 3145562 Japanese Patent No. 3942162 Japanese Patent No. 4069510 Japanese Patent No. 4093446 Japanese Unexamined Patent Publication No. 2002-244314

Claims (10)

A toner having at least a binder resin and an external additive, wherein the toner satisfies the following requirements (1) and (2).
(1) The volume average particle diameter (Dv) is 12 μm or more and 20 μm or less.
(2) The amount of silicone oil extracted with chloroform in the toner is 60 ppm or more and 140 ppm or less with respect to the toner. The electrophotographic toner according to claim 1, wherein the compaction density is 0.610 (g / cm ³ ) or less. The electrophotographic toner according to claim 1 or 2, wherein the volume average particle diameter (Dv) of the toner is 15 μm or more and 18 μm or less. The electrophotographic toner according to any one of claims 1 to 3, wherein the amount of the silicone oil extracted with chloroform in the toner is 100 ppm or more and 140 ppm or less with respect to the toner. The electrophotographic toner according to any one of claims 1 to 4, wherein the toner contains silica treated with silicone oil as an external additive. A two-component developer containing the toner and a carrier according to any one of claims 1 to 5, wherein the volume average particle diameter (Dv) of the toner is Dt, and the volume average particle diameter (Dv) of the carrier. ) Is 3.0 or more, and the particle size ratio Dc / Dt is 3.0 or more. A toner storage unit containing the toner according to any one of claims 1 to 5. Electrostatic latent image carrier and
An electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier,
A developing means including toner, which develops the electrostatic latent image formed on the electrostatic latent image carrier with toner to form a toner image.
A transfer means for transferring the toner image formed on the electrostatic latent image carrier to the surface of the recording medium, and
A fixing means for fixing a toner image transferred to the surface of the recording medium, and
An image forming apparatus, wherein the toner is the toner according to any one of claims 1 to 5. The image forming apparatus according to claim 8, wherein the image forming apparatus does not have a mechanism for applying a lubricant on the photoconductor drum. An electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier,
A developing step of developing the electrostatic latent image formed on the electrostatic latent image carrier with toner to form a toner image, and
A transfer step of transferring the toner image formed on the electrostatic latent image carrier to the surface of the recording medium, and
A fixing step of fixing the toner image transferred to the surface of the recording medium is included.
An image forming method, wherein the toner is the toner according to any one of claims 1 to 5.

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