JP2010060768A - Pulverization toner, process cartridge, image forming method and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pulverization toner capable of stabilizing toner fluidity while improving fix-releasability, and superior in chargeability, conveyance property and releasability, and to provide a process cartridge, an image forming method and an image forming apparatus using the toner. <P>SOLUTION: The pulverization toner comprises a toner base containing at least a colorant, a binder resin and a release agent, and inorganic fine particles, and is characterized in that: the inorganic fine particles contain large diameter particles having a primary particle diameter of 80-200 nm; the large particles adhere to the toner base at an adhesion strength of 50-85%; the toner shows a maximum endothermic peak of 60-90°C measured by differential scanning calorimetry; and the surface exposure amount of the adhesive component in the toner is 11-24 mg/g. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pulverized toner that is excellent in chargeability, transportability, and releasability due to stabilization of toner flow while improving fixing releasability, and a process cartridge, image forming method, and image formation using the toner Relates to the device.

Conventionally, in electrophotography, an electrostatic latent image formed by charging and exposing a photoreceptor surface is developed with toner to form a toner image, and the toner image is transferred to a recording medium such as transfer paper. Is fixed with a heat roll or the like to form an image.
Dry development methods employed in electrophotography, electrostatic recording, and the like include a method using a two-component developer composed of a toner and a carrier and a method using a one-component developer not containing a carrier.
Although the method using the two-component developer can obtain a stable and good image, it is likely to cause deterioration of the carrier and a change in the mixing ratio of the toner and the carrier, and so on. Images are difficult to obtain. In addition, there are difficulties in maintaining and managing the apparatus and making it compact. Therefore, a method using a one-component developer that does not have such drawbacks has been attracting attention.

  By the way, in any of the development methods, the toner surface is likely to be deteriorated because the toner is pressed by a pressing member (regulating blade) in the developing device or is vigorously contacted with the carrier. Therefore, the toner is required to have stable fluidity and toughness even if the toner is pressed or contacted.

In response to such a demand, for example, in the example of Patent Document 1, a large particle size silica having a particle size of 100 nm is treated at 32 m / s for 10 minutes using a Henschel mixer. Since the toner processed under such conditions is still weakly adhered, image quality such as white spots will be defective.
In Example 2 of Patent Document 2, large particle size silica is treated at 55 m / s for 15 minutes using a Henschel mixer. Even if processing is performed under the limit conditions of such a Henschel mixer, the applied energy is still small, and there is no improvement or ingenuity in the properties of the toner base, so it is not possible to sufficiently immobilize the large particle size silica on the toner base. There is a problem that high-quality images cannot be obtained stably.

  Therefore, it is possible to stabilize the toner fluidity while improving the fixing releasability, and the pulverized toner excellent in the chargeability, transportability, and releasability and related technology have not been provided yet. It is.

JP 2004-177799 A JP 2006-276062 A

  An object of the present invention is to solve various problems in the prior art and achieve the following objects. That is, the present invention can stabilize the toner fluidity while improving the fixing releasability, and pulverized toner excellent in chargeability, transportability, and releasability, and a process cartridge using the toner An object is to provide an image forming method and an image forming apparatus.

As a result of intensive studies by the present inventors in order to solve the above-described problems, the toner in the toner supply chamber is supplied to the developing roller by the supply roller and then pressed by the regulating blade to form a toner thin layer. In the one-component development method in which an electrostatic latent image is developed using a layer, the toner itself moves from the toner supply chamber to the regulating portion and is charged, so that the flow stability of the toner itself is very important. For this reason, inorganic fine particles such as silica are attached to the surface of the toner base to be fluidized, but the behavior of the inorganic fine particles varies greatly depending on the particle size, and small particles having a primary particle size of about 10 nm to 20 nm are fluidized. Although the effect is large, the embedding in the toner base due to stress is likely to proceed, and it is difficult to ensure flow stability. On the other hand, it has been found that large diameter particles exceeding 100 nm are difficult to fix on the toner surface, but are hardly buried in the toner base due to stress, and it is difficult to stabilize the fluidity of the toner.
Further, it has been found that when it is difficult to fix inorganic fine particles to the toner base, the particles move independently from the toner, so that they easily adhere to the photoreceptor and cause white spots.
Therefore, in the present invention, the fluidity of the toner is stabilized over a long period of time by defining the amount of the adhesive component for fixing the large particles on the surface of the toner base and the adhesion strength of the large particles. It was found that high-quality images can be stably obtained by preventing blurring (halftone unevenness) and white spots.

The present invention is based on the above findings by the present inventors, and means for solving the above problems are as follows. That is,
<1> A toner comprising a toner base containing at least a colorant, a binder resin, and a release agent, and inorganic fine particles,
The inorganic fine particles include large particles having a primary particle size of 80 nm to 200 nm, and the large particles adhere to the toner base with an adhesion strength of 50% to 85%;
The maximum endothermic peak of the toner measured by a differential scanning calorimeter (DSC) is 60 ° C. to 90 ° C., and the surface exposure amount of the adhesive component in the toner is 11 mg / g to 24 mg / g. Pulverized toner.
<2> The pulverized toner according to <1>, wherein the large-diameter particles are silica and the total amount of adhesive components in the toner is 4.0 mj / mg to 6.0 mj / mg.
<3> The toner surface abundance of large particles, a pulverized toner according to any one of the five / [mu] m ² to 10 pieces / [mu] m ² at which the items <1><2>.
<4> Any one of <1> to <3>, wherein the inorganic fine particles include small-diameter particles having a primary particle diameter of 7 nm to 30 nm, and a total amount of the inorganic fine particles is 3.0% by mass to 5.0% by mass. The pulverized toner described.
<5> The electrostatic latent image carrier and the electrostatic latent image formed on the electrostatic latent image carrier are developed using the pulverized toner according to any one of <1> to <4> and visible. A process cartridge having at least developing means for forming an image.
<6> An electrostatic latent image forming step for forming an electrostatic latent image on the electrostatic latent image carrier, and the pulverized toner according to any one of <1> to <4> Development step for forming a visible image by developing, a transfer step for transferring the visible image to a recording medium, and a fixing step for fixing the transfer image transferred to the recording medium. This is an image forming method.
<7> An electrostatic latent image carrier, an electrostatic latent image forming unit that forms an electrostatic latent image on the electrostatic latent image carrier, and the electrostatic latent image according to <1> to <4> A developing unit that develops a visible image by developing using the pulverized toner according to any one of the above, a transfer unit that transfers the visible image to a recording medium, and a fixing that fixes the transferred image transferred to the recording medium And an image forming apparatus.

  According to the present invention, conventional problems can be solved, toner flowability can be stabilized while improving fixing releasability, and grinding excellent in chargeability, transportability, and releasability A toner, a process cartridge using the toner, an image forming method, and an image forming apparatus can be provided.

(Pulverized toner)
The pulverized toner of the present invention comprises a toner base containing at least a colorant, a binder resin, and a release agent, and inorganic fine particles.

In the present invention, the inorganic fine particles include large particles having a primary particle size of 80 nm to 200 nm, and the primary particle size of the large particles is preferably 90 nm to 150 nm. When the primary particle size is less than 80 nm, the embedding of the inorganic fine particles due to stress proceeds and the fluidity decreases greatly. As a result, halftone blur may occur. Since the inorganic fine particles cannot be immobilized efficiently, white spots due to the inorganic fine particles may occur.
The primary particle size can be calculated by, for example, measuring the number of particles having a primary particle size of 50 nm or more for 30 visual fields using a scanning electron microscope (SEM) at a magnification of 20,000 and calculating the primary particle size. it can.

The large particles adhere to the toner base with an adhesion strength of 50% to 85%, and the adhesion strength is preferably 60% to 80%. If the adhesion strength is less than 50%, adhesion of the external additive is weak and white spots due to inorganic fine particles may occur. If the adhesion strength exceeds 85%, the embedding of the inorganic fine particles proceeds and the fluidity is increased. May cause half-tone blurring.
The adhesion strength of the large-diameter particles can be determined by, for example, adding 2 g of toner to 30 ml of a 10-fold diluted surfactant solution and thoroughly blending it, and then applying energy at 40 W for 1 minute using an ultrasonic homogenizer. The large-diameter particles were separated from the sample, washed and then dried. A toner pellet is prepared by applying a force of 1 N / cm ^{2 to 2} g of the treated toner and the untreated toner for 60 seconds, and using a wavelength dispersive X-ray fluorescence analyzer, The adhesion amount (for example, silicon in the case of silica) is quantified by a calibration curve method, and can be determined from the ratio of the adhesion amount of large-diameter particles before and after the treatment.
The adhesion strength can be adjusted by adjusting the viscosity of the adhesive component in the toner, the surface exposure amount of the adhesive component in the toner, the manufacturing conditions, and the like. In the case of the production conditions, a powder processing apparatus is used, and the higher the energy applied per unit time, the stronger the fixation. However, if too much energy is added, the resin dissolves due to heat generation, so it is preferable to treat with the lowest energy according to the particle size of the fine particles to be immobilized. This is the case when the primary particle size of the large particles is 80 nm to 200 nm. When the toner base satisfies the requirements of the present invention, it is preferable to apply energy of about 2.5 kW to 3.0 kW, whereby large particles can be efficiently fixed.
As the powder processing apparatus, for example, Nobilta, Ong mill (both surface modification (rounding process) machine manufactured by Hosokawa Micron Co., Ltd.) and the like can be suitably used in terms of energy.

The abundance of the large diameter particles on the toner surface is preferably 5 / μm ² to 10 / μm ² . If the toner particle abundance of the large-diameter particles is less than 5 particles / μm ² , the large-diameter particles are not present, so that the flow stability cannot be obtained, so that halftone blur is likely to occur. Yes, if it exceeds 10 / μm ² , white spots due to free inorganic fine particles are likely to occur because it is difficult to fix to the toner surface.
The amount of toner particles present on the toner surface is, for example, observed at 20,000 magnifications using a scanning electron microscope (SEM), and the number of particles having a primary particle diameter of 50 nm or more is counted for 30 visual fields. The toner surface abundance of large-diameter particles can be calculated in terms of toner unit area per 1 μm ² .

The surface exposure amount of the adhesive component in the toner is 11 mg / g to 24 mg / g, preferably 15 mg / g to 22 mg / g.
When the surface exposure amount of the adhesive component is less than 11 mg / g, the inorganic fine particles cannot be well fixed to the toner base, so that the fluidity is poor and white spots due to the inorganic fine particles may occur, exceeding 24 mg / g. As a result, the embedding of the inorganic fine particles due to the stress progresses and the fluidity of the toner decreases greatly, and as a result, halftone blur may occur.
The surface exposure amount of the adhesive component in the toner means the amount of the component extracted from the toner with hexane in a short time of 10 minutes.
Examples of the adhesive component include low molecular weight components such as a residual monomer of the binder resin, and wax. Since such an adhesive component has strong adhesiveness, it is possible to fix large diameter particles, which are generally difficult to fix on the toner surface, to the toner base.
For example, 1.0 g of toner and 10 mL of hexane are placed in a glass container, soaked for 10 minutes, then filtered, and the amount of residue after drying the filtrate is determined. be able to.
The surface exposure amount of the adhesive component can be adjusted by the amount of residual monomer, low molecular weight component, release agent, and the like. Also, under toner production conditions, a kneading disk having a shearing function (for example, a mortar-shaped fixed disk and a mortar-shaped rotating disk in the case of Miracle KCK kneader, manufactured by Asada Tekko Co., Ltd.) can be used to increase the dispersibility of the adhesive component. It is also possible to change the surface exposure by adjusting.

The total amount of adhesive components in the toner is preferably 4.0 mj / mg to 6.0 mj / mg. If the total amount of the adhesive component is less than 4.0 mj / mg, the inorganic fine particles cannot be well fixed to the toner base, and white spots due to the inorganic fine particles are likely to occur. If it exceeds the limit, the embedding of the inorganic fine particles due to the stress progresses, and the decrease in fluidity increases, and as a result, half-tone blurring is likely to occur.
The total amount of the adhesive component means the amount of the entire adhesive component contained in the entire toner base.
The total amount of the adhesive component of the toner is raised to 200 ° C. using, for example, a differential scanning calorimeter (DSC6200, manufactured by Seiko Instruments Inc.), and then cooled to 0 ° C. at a temperature lowering rate of 10 ° C./min. The measured sample is measured at a temperature rising rate of 10 ° C./min, and can be obtained from the area surrounded by the intersection of the tangent line from the high temperature side and the low temperature side endothermic peak portion.
The total amount of the adhesive component can be adjusted by the monomer composition of the binder resin, the molecular weight, the low molecular weight component, and the like.

The toner has a maximum endothermic peak measured by a differential scanning calorimeter (DSC) of 60 ° C to 90 ° C, preferably 65 ° C to 85 ° C. If the maximum endothermic peak is less than 60 ° C., the embedding of the inorganic fine particles is promoted, so that the fluidity is poor and halftone blur may occur. If the maximum endothermic peak exceeds 90 ° C., the inorganic fine particles are generated by the heat of the adhesive component. Since immobilization is difficult, white spots due to inorganic fine particles may occur.
The maximum endothermic peak due to DSC of the toner indicates the thermal characteristics of the component constituting the adhesive component in the toner. Since fixing of the large-diameter particles is performed by applying heat to the adhesive component, there is an optimum thermal characteristic for obtaining an effective adhesive action without affecting the toner base.
The maximum endothermic peak measured by DSC of the toner can be adjusted by the molecular weight of the binder resin, the low molecular weight component, the melting point of the release agent, and the like.

The inorganic fine particles preferably include small particles having a primary particle diameter of 7 nm to 30 nm, and the primary particle diameter of the small particles is more preferably 10 nm to 25 nm. The primary particle diameter of the small-diameter particles is not less than 7 nm, and if it exceeds 30 nm, the effect of fluidization is reduced, so that the effect of adding the small-diameter particles is hardly seen, and the blur occurs from the beginning. Sometimes.
The primary particle size of the small-sized particles is, for example, measured by using a scanning electron microscope (SEM) at a magnification of 20,000, measuring the number of particles having a primary particle size of 7 nm or more for 30 visual fields, and calculating the primary particle size. can do.
The total amount of the inorganic fine particles is preferably 3.0% by mass to 5.0% by mass. If the total amount of the inorganic fine particles is less than 3.0% by mass, the toner may not be sufficiently fluidized by the inorganic fine particles, so that halftone blur may occur. If the total amount exceeds 5.0% by mass, the toner surface Since it is difficult to immobilize on the surface, white spots due to free inorganic fine particles may occur.

  The inorganic fine particles are not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include silica, hydrophobic silica, fatty acid metal salts (such as zinc stearate and aluminum stearate), and metal oxides (titania, Alumina, tin oxide, antimony oxide, etc.). Among these, silica is particularly preferable from the viewpoint of imparting fluidity to the toner.

  As the silica, commercially available products can be used. Examples of the commercially available products include HDK H2000, HDK H2000 / 4, HDK H2050EP, HVK21, HDK H1303 (all manufactured by Hoechst); R972, R974, RX200, RY200, R202, R805, R812, RX-50, NAX50 (all manufactured by Nippon Aerosil Co., Ltd.), TG-811F, EP-BR041, EP-BR412, EP-BR405 (all manufactured by CAB-O-SIL), X-24 (manufactured by Shin-Etsu Chemical Co., Ltd.), MSN-005 (manufactured by Teika), and the like.

  The toner base in the pulverized toner of the present invention contains at least a colorant, a binder resin, and a release agent, and further contains other components as necessary.

-Binder resin-
There is no restriction | limiting in particular as said binder resin, Although it can select suitably according to the objective, From a viewpoint of the stress resistance in a developing device, a polyester-type resin is preferable.
As the polyester resin, a polyester resin obtained by polycondensation of a polyhydric alcohol component and a polyvalent carboxylic acid component is suitable.

Examples of the dihydric alcohol component among the polyhydric alcohol components include polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3,3) -2,2 -Bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2,0) -2,2-bis (4-hydroxyphenyl) Bisphenol A alkylene oxide adducts such as propane; ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol 1,6-hexanediol, 1,4-cyclohexanedimethanol , Dipropylene glycol, polyethylene glycol, polytetramethylene glycol, bisphenol A, hydrogenated bisphenol A, and the like.
Among the polyhydric alcohol components, trihydric or higher alcohol components include, for example, sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1, 2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5 -Trihydroxymethylbenzene and the like.

Among the polyvalent carboxylic acid components, examples of the divalent carboxylic acid component include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, and adipine. Acid, sebacic acid, azelaic acid, malonic acid, n-dodecenyl succinic acid, isododecenyl succinic acid, n-dodecyl succinic acid, isododecyl succinic acid, n-octenyl succinic acid, isooctenyl succinic acid, n-octyl succinic acid, iso Examples include octyl succinic acid, anhydrides or lower alkyl esters of these acids.
Examples of the trivalent or higher carboxylic acid component among the polyvalent carboxylic acid components include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 1,2,5-benzenetricarboxylic acid, 2,5,7- Naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane 1,2,4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, empole trimer acid, anhydrides of these acids, lower alkyl Examples include esters.

In the present invention, the polyester resin is a mixture of a polyester resin raw material monomer, a vinyl resin raw material monomer, and a monomer that reacts with both resin raw material monomers, and the polyester resin is obtained in the same container. A resin obtained by carrying out a polymerization reaction and a radical polymerization reaction for obtaining a vinyl resin in parallel (hereinafter simply referred to as “vinyl polyester resin”) can also be suitably used. In addition, the monomer which reacts with the raw material monomer of both resin is a monomer which can be used for both reaction of a condensation polymerization reaction and a radical polymerization reaction in other words. That is, it is a monomer having a carboxy group that can undergo a condensation polymerization reaction and a vinyl group that can undergo a radical polymerization reaction, and examples thereof include fumaric acid, maleic acid, acrylic acid, and methacrylic acid.
Examples of the raw material monomer for the polyester resin include the polyhydric alcohol component and the polyvalent carboxylic acid component described above. Examples of the raw material monomer for the vinyl resin include styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, α-methyl styrene, p-ethyl styrene, 2,4-dimethyl styrene, p-tert- Styrene or styrene derivatives such as butyl styrene and p-chlorostyrene; Ethylene unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; methyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate , Isobutyl methacrylate, t-butyl methacrylate, n-pentyl methacrylate, isopentyl methacrylate, neopentyl methacrylate, 3- (methyl) butyl methacrylate, hexyl methacrylate, octyl methacrylate, nonyl methacrylate, meta Methacrylic acid alkyl esters such as decyl crylate, undecyl methacrylate, dodecyl methacrylate; methyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, acrylic Alkyl acrylates such as n-pentyl acid, isopentyl acrylate, neopentyl acrylate, 3- (methyl) butyl acrylate, hexyl acrylate, octyl acrylate, nonyl acrylate, decyl acrylate, undecyl acrylate, and dodecyl acrylate Esters; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid; acrylonitrile, maleic acid ester, itaconic acid ester, vinyl chloride, vinyl acetate, vinyl benzoate, vinylmethylethyl Ton, vinyl hexyl ketone, vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether.

  As a polymerization initiator when polymerizing the raw material monomer of the vinyl resin, for example, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1 Azo or diazo polymerization initiators such as' -azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile; benzoyl peroxide, dicumyl peroxide, And peroxide polymerization initiators such as methyl ethyl ketone peroxide, isopropyl peroxycarbonate, lauroyl peroxide, and the like.

As the binder resin, various polyester resins as described above are preferably used. Of these, from the viewpoint of further improving the separability and offset resistance as an oilless fixing toner, the first binder shown below is used. It is more preferable to use a resin and a second binder resin.
A more preferred first binder resin is a polyester resin obtained by polycondensation of the above-mentioned polyhydric alcohol component and polyhydric carboxylic acid component, particularly a bisphenol A alkylene oxide adduct as the polyhydric alcohol component. It is a polyester resin obtained using terephthalic acid and fumaric acid as the acid component.
More preferable second binder resins are vinyl polyester resins, in particular, bisphenol A alkylene oxide adduct, terephthalic acid, trimellitic acid and succinic acid are used as raw material monomers for polyester resins, and styrene and butyl acrylate are used as raw material monomers for vinyl resins. And a vinyl-based polyester resin obtained using fumaric acid as a bireactive monomer.

  In the present invention, it is preferable that a hydrocarbon wax is internally added during the synthesis of the first binder resin. In order to add the hydrocarbon wax to the first binder resin in advance, when the first binder resin is synthesized, the hydrocarbon wax is added to the monomer for synthesizing the first binder resin. Then, the first binder resin may be synthesized. For example, the polycondensation reaction may be performed in a state where a hydrocarbon wax is added to an acid monomer and an alcohol monomer constituting the polyester resin as the first binder resin. When the first binder resin is a vinyl-based polyester resin, the vinyl-based resin raw material monomer is dropped into the polyester resin raw-material monomer while stirring and heating the monomer while the hydrocarbon-based wax is added. Then, a polycondensation reaction and a radical polymerization reaction may be performed.

Generally, the lower the polarity of the wax, the better the releasability from the roller as the fixing member.
As the wax used in the present invention, paraffin wax having no polarity is preferable.
The melting point of the wax is an endothermic peak of the wax at the time of temperature rise measured by a differential scanning calorimeter (DSC), and is preferably in the range of 70 ° C to 90 ° C. If the endothermic peak is higher than 90 ° C., the melting of the wax in the fixing process becomes insufficient, so that separation from the fixing member cannot be secured, and if it is lower than 70 ° C., the toner particles are in a high temperature and high humidity environment. Problems arise in storage stability, such as melting. In order to provide a margin for fixing separation at a low temperature, the melting point of the wax is preferably 70 ° C to 85 ° C, more preferably 70 ° C to 80 ° C.
Moreover, it is preferable that the half value width of the wax endothermic peak at the time of temperature rise measured by a differential scanning calorimeter (DSC) is 7 ° C. or less. Since the melting point of the wax in the present invention is relatively low, a wax whose endothermic peak is broad, that is, melted from a low temperature range, adversely affects the storage stability of the toner.

-Colorant-
There is no restriction | limiting in particular as said coloring agent, The well-known pigment and dye conventionally used as a coloring agent of a full color toner can be used. For example, carbon black, aniline blue, calcoil blue, chrome yellow, ultramarine blue, duPont oil red, quinoline yellow, methylene blue chloride, copper phthalocyanine, malachite green oxalate, lamp black, rose bengal, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 184, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 74, C.I. I. Solvent Yellow 162, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 185, C.I. I. Pigment blue 15: 1, C.I. I. And CI Pigment Blue 15: 3.

  The content of the colorant in the toner is preferably 2 to 15 parts by mass with respect to 100 parts by mass of the binder resin. It is preferable from the viewpoint of dispersibility that the colorant is used in the form of a masterbatch dispersed in a mixed binder resin of the first binder resin and the second binder resin used. The addition amount of the masterbatch may be an amount such that the amount of the colorant contained is within the above range. 20 mass%-40 mass% are suitable for the coloring agent content rate in a masterbatch.

-Charge control agent-
In the toner of the present invention, a known charge control agent conventionally used in full color toners may be used.
The charge control agent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy Amines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus simple substances or compounds, tungsten simple substances or compounds, fluorine activators, salicylic acid metal salts, metal salts of salicylic acid derivatives, etc. It is done.
As the charge control agent, specifically, commercially available products can be used. Examples of the commercially available products include bontron 03 of a nigrosine dye, bontron P-51 of a quaternary ammonium salt, and bontron of a metal-containing azo dye. S-34, E-82 of oxynaphthoic acid metal complex, E-84 of salicylic acid metal complex, E-89 of phenolic condensate (above, manufactured by Orient Chemical Co., Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, manufactured by Hodogaya Chemical Co., Ltd.), quaternary ammonium salt copy charge PSY VP2038, triphenylmethane derivative copy blue PR, quaternary ammonium salt copy charge NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, boron complex That LR-147 (manufactured by Japan Carlit Co., Ltd.), copper phthalocyanine, perylene, quinacridone, azo pigments, sulfonate group, carboxyl group, and polymer compounds having a functional group such as quaternary ammonium salts. Among these, a substance that controls the negative polarity of the toner is particularly preferable.
The content of the charge control agent is not particularly limited, and is determined by the toner production method including the type of binder resin, the presence or absence of additives used as necessary, and the dispersion method. Although not limited, 0.1 mass part-10 mass parts are preferable with respect to 100 mass parts of binder resin, and 0.2 mass part-5 mass parts are more preferable. When the content exceeds 10 parts by mass, the chargeability of the toner is too high, the effect of the charge control agent is diminished, the electrostatic attraction force with the developing roller is increased, and the flowability of the developer is reduced. The image density may be reduced.

<Toner production method>
In the toner of the present invention, at least a colorant, a binder resin, and a release agent are mixed, kneaded, pulverized, and classified to obtain a toner base (colored particles) having a desired particle size. It can manufacture by mixing.

The pulverization method is a method of obtaining the toner base by, for example, melting or kneading a toner material, pulverizing, classifying, or the like. In the case of the pulverization method, the shape may be controlled by applying a mechanical impact force to the obtained toner base for the purpose of increasing the average circularity of the toner. In this case, the mechanical impact force can be applied to the toner base using an apparatus such as a hybridizer or mechanofusion.
The above toner materials are mixed, and the mixture is charged into a melt kneader and melt kneaded. As the melt kneader, for example, a uniaxial continuous kneader, a biaxial continuous kneader, or a batch kneader using a roll mill can be used. For example, KTK type twin screw extruder manufactured by Kobe Steel, TEM type extruder manufactured by Toshiba Machine Co., Ltd., twin screw extruder manufactured by Casey Kay, PCM type twin screw extruder manufactured by Ikegai Co., Ltd. Used for. This melt-kneading is preferably performed under appropriate conditions so as not to cause the molecular chains of the binder resin to be broken. Specifically, the melt-kneading temperature is determined with reference to the softening point of the binder resin. If the temperature is higher than the softening point, cutting is severe, and if the temperature is too low, dispersion may not proceed.

  In the pulverization, the kneaded product obtained by the kneading is pulverized. In this pulverization, it is preferable that the kneaded material is first coarsely pulverized and then finely pulverized. At this time, a method of pulverizing by colliding with a collision plate in a jet stream, pulverizing particles by colliding with each other in a jet stream, or pulverizing with a narrow gap between a mechanically rotating rotor and a stator is preferably used.

In the classification, the pulverized product obtained by the pulverization is classified and adjusted to particles having a predetermined particle diameter. The classification can be performed by removing the fine particle portion by, for example, a cyclone, a decanter, centrifugation, or the like.
After the pulverization and classification are completed, the pulverized product is classified into an air stream by centrifugal force or the like to produce a toner having a predetermined particle size.

The toner obtained has a volume average particle size of preferably 3 μm to 15 μm, more preferably 3 μm to 9 μm, and even more preferably 5 μm to 8 μm.
The volume average particle diameter of the toner can be measured using, for example, Coulter Multisizer II (manufactured by Coulter).

  The coloration of the toner is not particularly limited and may be appropriately selected according to the purpose, and may be at least one selected from black toner, cyan toner, magenta toner, and yellow toner. Can be obtained by appropriately selecting the type of the colorant, and is preferably a color toner.

(Process cartridge)
The process cartridge of the present invention develops an electrostatic latent image carrier carrying an electrostatic latent image and the electrostatic latent image carried on the electrostatic latent image carrier using a developer to form a visible image. At least a developing means for forming the film, and other means appropriately selected as necessary.
The developing means includes at least a developer container that contains the developer of the present invention, and a developer carrier that carries and conveys the developer contained in the developer container. In addition, a layer thickness regulating member for regulating the toner layer thickness to be carried may be provided if necessary.
The process cartridge can be detachably provided in various electrophotographic image forming apparatuses, but it is particularly preferable that the process cartridge is detachably provided in the image forming apparatus of the present invention described later.

Here, for example, as shown in FIG. 1, the process cartridge includes a photosensitive member 101, and includes a charging unit 102, a developing unit 104, a transfer unit 108, and a cleaning unit 107, and other members as necessary. It has. In FIG. 1, reference numeral 103 denotes exposure by an exposure unit, and a light source capable of writing with high resolution is used. Reference numeral 105 denotes a recording medium. As the photoreceptor 101, the same one as an image forming apparatus described later can be used. An arbitrary charging member is used as the charging unit 102.
Next, an image forming process using the process cartridge shown in FIG. 1 will be described. The photosensitive member 101 is exposed to the surface by charging by the charging unit 102 and exposure 103 by the exposure unit (not shown) while rotating in the direction of the arrow. An electrostatic latent image corresponding to the image is formed. The electrostatic latent image is developed with toner by the developing unit 104, and the toner image is transferred to the recording medium 105 by the transfer unit 108 and printed out. Next, the surface of the photoconductor after the image transfer is cleaned by the cleaning unit 107 and further neutralized by a neutralizing unit (not shown), and the above operation is repeated again.

(Image forming method and image forming apparatus)
The image forming method of the present invention includes at least an electrostatic latent image forming step, a developing step, a transfer step, and a fixing step, and other steps appropriately selected as necessary, for example, a static elimination step, a cleaning step. , Including recycling process, control process, etc.
The image forming apparatus of the present invention includes at least an electrostatic latent image carrier, an electrostatic latent image forming unit, a developing unit, a transfer unit, and a fixing unit, and further appropriately selected as necessary. It has other means, for example, static elimination means, cleaning means, recycling means, control means and the like.

The electrostatic latent image forming step is a step of forming an electrostatic latent image on the electrostatic latent image carrier.
The electrostatic latent image carrier (sometimes referred to as “electrophotographic photosensitive member” or “photosensitive member”) is not particularly limited in terms of material, shape, structure, size, etc. Although it can be selected as appropriate, the shape thereof is preferably a drum shape, and examples of the material thereof include inorganic photoreceptors such as amorphous silicon and selenium, organic photoreceptors (OPC) such as polysilane and phthalopolymethine, and the like. Is mentioned. Among these, amorphous silicon or the like is preferable in terms of long life.

  The formation of the electrostatic latent image can be performed, for example, by uniformly charging the surface of the electrostatic latent image carrier and then performing imagewise exposure, and is performed by the electrostatic latent image forming unit. be able to. The electrostatic latent image forming means includes, for example, at least a charger that uniformly charges the surface of the electrostatic latent image carrier and an exposure device that exposes the surface of the electrostatic latent image carrier imagewise. Prepare.

The charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using the charger.
The charger is not particularly limited and may be appropriately selected depending on the purpose. For example, a known contact charging device including a conductive or semiconductive roll, brush, film, rubber blade, etc. And non-contact chargers using corona discharge such as corotrons and corotrons.
The charger is preferably one that is arranged in contact or non-contact with the electrostatic latent image carrier and charges the surface of the electrostatic latent image carrier by applying a direct current and an alternating voltage.
Further, the charger is a charging roller disposed in a non-contact proximity to the electrostatic latent image carrier via a gap tape, and the electrostatic latent image is carried by applying a direct current and an alternating voltage to the charging roller. Those that charge the body surface are preferred.

The exposure can be performed, for example, by exposing the surface of the latent electrostatic image bearing member imagewise using the exposure device.
The exposure device is not particularly limited as long as it can expose the surface of the electrostatic latent image carrier charged by the charger so as to form an image to be formed, and is appropriately selected according to the purpose. For example, various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system can be used.
In the present invention, a back light system in which imagewise exposure is performed from the back side of the electrostatic latent image carrier may be employed.

-Development process and development means-
The developing step is a step of developing the electrostatic latent image using the developer of the present invention to form a visible image.
The visible image can be formed, for example, by developing the electrostatic latent image using the toner or the developer, and can be performed by the developing unit.
The developing means is not particularly limited as long as it can be developed using toner or developer, for example, and can be appropriately selected from known ones. For example, the toner or developer is accommodated, and Preferable examples include those having at least developing means capable of bringing the toner or developer into contact or non-contact with the electrostatic latent image.

The developing means is preferably a dry developing type. Further, it may be a monochromatic developing unit or a multi-color developing unit. For example, a stirrer for charging the toner or the developer by frictional stirring and a rotatable magnet roller are provided. Preferred examples include those possessed.
As the one-component developing means, for example, a one-component developing device having a developer carrier to which toner is supplied and a layer thickness regulating member that forms a thin layer of toner on the surface of the developer carrier is preferably used. .

  Here, FIG. 8 is a schematic view showing an example of a one-component developing device. This one-component developing device uses a one-component developer made of toner, forms a toner layer on a developing roller 402 as a developer carrying member, and uses the toner layer on the developing roller 402 as an electrostatic latent image carrying member. The photosensitive drum 10 is conveyed so as to be in contact with the photosensitive drum 10 to perform contact one-component development for developing the electrostatic latent image on the photosensitive drum 10.

  In FIG. 8, the toner in the casing 401 is agitated by the rotation of an agitator 411 as a stirring means, and mechanically supplied to a supply roller 412 as a toner supply member. The supply roller 412 is formed of polyurethane foam or the like, has flexibility, and has a structure in which toner can be easily held by a cell having a diameter of 50 μm to 500 μm. Further, the supply roller has a relatively low JIS-A hardness of 10 to 30 °, and can be brought into contact with the developing roller 402 uniformly.

  The supply roller 412 is driven to rotate in the same direction as the developing roller 402, that is, the surface of the supply roller 412 moves in the opposite direction at the opposing portion of both rollers. The linear speed ratio (supply roller / developing roller) of both rollers is preferably 0.5 to 1.5. Further, the supply roller 412 may be rotated so that the surfaces of the supply roller 412 move in the same direction as the developing roller 402, that is, at the opposite portions of the two rollers. In this embodiment, the supply roller 412 rotates in the same direction as the developing roller 402, and the linear speed ratio is set to 0.9. The biting amount of the supply roller 412 with respect to the developing roller 402 is set to 0.5 to 1.5 mm. In the present embodiment, when the unit effective width is 240 mm (A4 size vertical), the required torque is 14.7 to 24.5 N · cm.

The developing roller 402 has a surface layer made of a rubber material on a conductive substrate, has a diameter of 10 to 30 mm, and appropriately roughens the surface to have a surface roughness Rz of 1 to 4 μm. The value of the surface roughness Rz is preferably 13 to 80% with respect to the average particle diameter of the toner. As a result, the toner is conveyed without being buried in the surface of the developing roller 402. In particular, the surface roughness Rz of the developing roller 402 is preferably in the range of 20 to 30% of the average particle diameter of the toner so as not to retain the toner with extremely low charge.
Examples of the rubber material include silicone rubber, butadiene rubber, NBR rubber, hydrin rubber, EPDM rubber, and the like. Further, it is preferable to coat the surface of the developing roller 402 with a coating layer in order to stabilize the quality with time. Examples of the material for the coating layer include silicone materials and Teflon (registered trademark) materials. The silicone material is excellent in toner chargeability, and the Teflon (registered trademark) material is excellent in releasability. In order to obtain conductivity, a conductive material such as carbon black can be appropriately contained. The thickness of the coat layer is preferably 5 to 50 μm. If it is out of this range, problems such as easy cracking may occur.

Toner having a predetermined polarity (negative polarity in the case of the present embodiment) existing on or inside the supply roller 412 is pinched by the developing roller 402 that rotates in the opposite direction at the contact point by rotation, thereby causing friction. A negatively charged charge is obtained by the charging effect and is held on the developing roller 402 by an electrostatic force and by a conveying effect by the surface roughness of the developing roller 402. However, the toner layer on the developing roller 402 at this time is not uniform and is considerably excessively attached (1 to 3 mg / cm ² ). Therefore, a toner thin layer having a uniform layer thickness is formed on the developing roller 402 by bringing a regulating blade 413 as a layer thickness regulating member into contact with the developing roller 402, and at the same time, the toner pressed by the regulating blade The toner can obtain a desired charge by contacting with the developing roller. The restriction blade 413 is a so-called belly contact where the tip is directed downstream with respect to the rotation direction of the developing roller 402 and the central portion of the restriction blade 413 contacts, but it can be set in the reverse direction. It is also possible to realize edge contact.
As the material of the regulating blade, a metal such as SUS304 is preferable, and the thickness is 0.1 to 0.15 mm. In addition to the metal, a rubber material such as polyurethane rubber having a thickness of 1 to 2 mm or a resin material having a relatively high hardness such as a silicone resin can be used. In addition, since the resistance can be reduced by mixing carbon black or the like other than metal, it is possible to form an electric field between the developing roller 402 by connecting a bias power source.

The regulating blade 413 as the layer thickness regulating member is preferably 10 to 15 mm as a free end length from the holder. If the free end length exceeds 15 mm, the developing means becomes large and cannot be stored compactly in the image forming apparatus. If it is less than 10 mm, vibration occurs when the regulating blade comes into contact with the surface of the developing roller 402. In some cases, an abnormal image such as unevenness in the horizontal direction is likely to occur on the image.
The contact pressure of the regulating blade 413 is preferably in the range of 0.049 to 2.45 N / cm. When the contact pressure exceeds 2.45 N / cm, the toner adhesion amount on the developing roller 402 decreases and the toner charge amount increases excessively, so the development amount may decrease and the image density may decrease. If it is less than 0.049 N / cm, the thin layer may not be formed uniformly, and the toner mass may pass through the regulating blade, and the image quality may be significantly lowered. In this embodiment, the developing roller 402 has a JIS-A hardness of 30 °, the regulating blade 413 is a SUS plate having a thickness of 0.1 mm, and the contact pressure is set to 60 gf / cm. At this time, the target toner adhesion amount on the developing roller could be obtained.

Further, the contact angle of the regulating blade 413 as the layer thickness regulating member is preferably 10 to 45 ° with respect to the tangent line of the developing roller 402 in the direction in which the tip faces the downstream side of the developing roller 402. A portion unnecessary for forming a thin layer of toner sandwiched between the regulating blade 413 and the developing roller 402 is peeled off from the developing roller 402 and is 0.4 to 0.8 mg / cm ² per unit area which is a target range. A thin layer having a uniform thickness is formed. The toner charge at this time is finally in the range of −10 to −30 μC / g in this embodiment, and is developed to face the electrostatic latent image on the photosensitive drum 10.

-Transfer process and transfer means-
The transfer step is a step of transferring the visible image onto a recording medium. After the primary transfer of the visible image onto the intermediate transfer member using an intermediate transfer member, the visible image is transferred onto the recording medium. A primary transfer step of forming a composite transfer image by transferring a visible image onto an intermediate transfer body using two or more colors, preferably full color toner as the toner, and a composite transfer image; A mode including a secondary transfer step of transferring the transfer image onto the recording medium is more preferable.
The transfer can be performed, for example, by charging the latent electrostatic image bearing member (photoconductor) of the visible image using a transfer charger, and can be performed by the transfer unit. The transfer means includes a primary transfer means for transferring a visible image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer means for transferring the composite transfer image onto a recording medium. Embodiments are preferred.
The intermediate transfer member is not particularly limited and may be appropriately selected from known transfer members according to the purpose. For example, a transfer belt and the like are preferable.

The transfer means (the primary transfer means and the secondary transfer means) is a transfer for peeling and charging the visible image formed on the electrostatic latent image carrier (photoconductor) to the recording medium side. It is preferable to have at least a vessel. The number of the transfer means may be one, or two or more. Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.
The recording medium is not particularly limited and can be appropriately selected from known recording media (recording paper).

The fixing step is a step of fixing the visible image transferred to the recording medium using a fixing device, and may be performed each time the developer of each color is transferred to the recording medium, or the developer of each color. On the other hand, it may be carried out at the same time in a state where these are laminated.
There is no restriction | limiting in particular as said fixing device, Although it can select suitably according to the objective, A well-known heating-pressing means is suitable. Examples of the heating and pressing means include a combination of a heating roller and a pressure roller, a combination of a heating roller, a pressure roller, and an endless belt.
The fixing device includes a heating body including a heating element, a film in contact with the heating body, and a pressure member in pressure contact with the heating body through the film, and the film and the pressure member It is preferably a unit that heats and fixes a recording medium on which an unfixed image is formed. The heating in the heating and pressing means is usually preferably 80 ° C to 200 ° C.
In the present invention, for example, a known optical fixing device may be used together with or in place of the fixing step and the fixing unit depending on the purpose.

The neutralization step is a step of performing neutralization by applying a neutralization bias to the electrostatic latent image carrier, and can be suitably performed by a neutralization unit.
The neutralization means is not particularly limited, and may be appropriately selected from known neutralizers as long as it can apply a neutralization bias to the electrostatic latent image carrier. Preferably mentioned.

The cleaning step is a step of removing the toner remaining on the electrostatic latent image carrier, and can be suitably performed by a cleaning unit.
The cleaning unit is not particularly limited, and may be selected from known cleaners as long as it can remove the toner remaining on the electrostatic latent image carrier. For example, a magnetic brush cleaner Suitable examples include electrostatic brush cleaners, magnetic roller cleaners, blade cleaners, brush cleaners, web cleaners, and the like.

The recycling step is a step of recycling the toner removed by the cleaning step to the developing unit, and can be suitably performed by the recycling unit.
There is no restriction | limiting in particular as said recycling means, A well-known conveyance means etc. are mentioned.

The control step is a step of controlling each step, and each step can be suitably performed by a control means.
The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.

  Here, an aspect of carrying out the image forming method of the present invention by the image forming apparatus will be described with reference to FIG. An image forming apparatus 100 shown in FIG. 2 includes a photosensitive drum 10 (photosensitive member 10) as the electrostatic latent image carrier, a charging roller 20 as the charging unit, and an exposure device 30 as the exposure unit. A developing device 40 as the developing means, an intermediate transfer member 50, a cleaning device 60 as the cleaning means having a cleaning blade, and a static elimination lamp 70 as the static elimination means.

  The intermediate transfer member 50 is an endless belt, and is designed so as to be movable in the direction of the arrow in the figure by three rollers 51 that are arranged on the inner side and stretch the belt. Part of the three rollers 51 also functions as a transfer bias roller that can apply a predetermined transfer bias (primary transfer bias) to the intermediate transfer member 50. An intermediate transfer member cleaning blade 90 is disposed in the vicinity of the intermediate transfer member 50, and a transfer bias for transferring a visible image (toner image) to the recording medium 95 (secondary transfer) is applied. Possible transfer rollers 80 as the transfer means are arranged to face each other. Around the intermediate transfer member 50, a corona charger 58 for applying a charge to the visible image on the intermediate transfer member 50 is connected to the electrostatic latent image carrier 10 in the rotation direction of the intermediate transfer member 50. The contact portion between the intermediate transfer member 50 and the contact portion between the intermediate transfer member 50 and the recording medium 95 is disposed.

  The developing device 40 includes a developing belt 41 as a developer carrying member, and a black developing unit 45K, a yellow developing unit 45Y, a magenta developing unit 45M, and a cyan developing unit 45C provided around the developing belt 41. Yes. The black developing unit 45K includes a developer accommodating portion 42K, a developer supply roller 43K, and a developing roller 44K. The yellow developing unit 45Y includes a developer container 42Y, a developer supply roller 43Y, and a developing roller 44Y. The magenta developing unit 45M includes a developer container 42M, a developer supply roller 43M, and a developing roller 44M. The cyan developing unit 45C includes a developer container 42C, a developer supply roller 43C, and a developing roller 44C. Further, the developing belt 41 is an endless belt, is rotatably stretched by a plurality of belt rollers, and a part thereof is in contact with the electrostatic latent image carrier 10.

  In the image forming apparatus 100 shown in FIG. 2, for example, the charging roller 20 charges the photosensitive drum 10 uniformly. The exposure device 30 performs imagewise exposure on the photosensitive drum 10 to form an electrostatic latent image. The electrostatic latent image formed on the photosensitive drum 10 is developed by supplying toner from the developing device 40 to form a visible image (toner image). The visible image (toner image) is transferred (primary transfer) onto the intermediate transfer member 50 by the voltage applied from the roller 51, and further transferred (secondary transfer) onto the transfer paper 95. As a result, a transfer image is formed on the transfer paper 95. The residual toner on the photoconductor 10 is removed by the cleaning device 60, and the charge on the photoconductor 10 is temporarily removed by the charge eliminating lamp 70.

  Another mode for carrying out the image forming method of the present invention by the image forming apparatus will be described with reference to FIG. The image forming apparatus 100 shown in FIG. 3 does not include the developing belt 41 in the image forming apparatus 100 shown in FIG. 2, and a black developing unit 45K, a yellow developing unit 45Y, a magenta developing unit 45M, and Except for the fact that the cyan developing unit 45C is arranged directly opposite, it has the same configuration as the image forming apparatus 100 shown in FIG. In FIG. 3, the same components as those in FIG. 2 are denoted by the same reference numerals.

Another mode for carrying out the image forming method of the present invention by the image forming apparatus will be described with reference to FIG. The tandem type image forming apparatus shown in FIG. 4 is a tandem type color image forming apparatus. The tandem image forming apparatus includes a copying apparatus main body 150, a paper feed table 200, a scanner 300, and an automatic document feeder (ADF) 400.
The copying apparatus main body 150 is provided with an endless belt-like intermediate transfer member 50 at the center. The intermediate transfer member 50 is stretched around the support rollers 14, 15 and 16, and can be rotated clockwise in FIG. 4. An intermediate transfer body cleaning device 17 for removing residual toner on the intermediate transfer body 50 is disposed in the vicinity of the support roller 15. The intermediate transfer body 50 stretched by the support roller 14 and the support roller 15 is a tandem type in which four image forming means 18 of yellow, cyan, magenta, and black are arranged in parallel and facing each other along the conveyance direction. A developing device 120 is disposed. An exposure device 21 is disposed in the vicinity of the tandem developing device 120. A secondary transfer device 22 is disposed on the side of the intermediate transfer member 50 opposite to the side on which the tandem developing device 120 is disposed. In the secondary transfer device 22, a secondary transfer belt 24, which is an endless belt, is stretched around a pair of rollers 23, and the transfer paper conveyed on the secondary transfer belt 24 and the intermediate transfer body 50 are in contact with each other. Is possible. A fixing device 25 is disposed in the vicinity of the secondary transfer device 22. The fixing device 25 includes a fixing belt 26 that is an endless belt, and a pressure roller 27 that is pressed against the fixing belt 26.
In the tandem type image forming apparatus, a sheet reversing device 28 for reversing the transfer paper for image formation on both sides of the transfer paper is disposed in the vicinity of the secondary transfer device 22 and the fixing device 25. Yes.

  Next, formation of a full-color image (color copy) using the tandem developing device 120 will be described. That is, first, a document is set on the document table 130 of the automatic document feeder (ADF) 400, or the automatic document feeder 400 is opened and the document is set on the contact glass 32 of the scanner 300. 400 is closed.

  When a start switch (not shown) is pressed, when the document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the contact glass 32. Immediately after that, the scanner 300 is driven, and the first traveling body 33 and the second traveling body 34 travel. At this time, light from the light source is irradiated by the first traveling body 33 and reflected light from the document surface is reflected by the mirror in the second traveling body 34 and is received by the reading sensor 36 through the imaging lens 35 to be color. An original (color image) is read and used as black, yellow, magenta, and cyan image information.

  Each image information of black, yellow, magenta, and cyan is stored in each image forming unit 18 (black image forming unit, yellow image forming unit, magenta image forming unit, and cyan image) in the tandem developing device 120. Each of the image forming units forms black, yellow, magenta, and cyan toner images. That is, each image forming means 18 (black image forming means, yellow image forming means, magenta image forming means, and cyan image forming means) in the tandem type developing device 120 is a static image as shown in FIG. An electrostatic latent image carrier 10 (an electrostatic latent image carrier 10K for black, an electrostatic latent image carrier 10Y for yellow, an electrostatic latent image carrier 10M for magenta, and an electrostatic latent image carrier 10C for cyan); The electrostatic latent image bearing member 10 is uniformly charged, and the electrostatic latent image bearing member is exposed (L in FIG. 5) for each color image corresponding to each color image information. An exposure device that forms an electrostatic latent image corresponding to each color image on the electrostatic latent image carrier, and each color toner (black toner, yellow toner, magenta toner, and cyan toner) Develop with A developing device 61 for forming a toner image with each color toner, a transfer charger 62 for transferring the toner image onto the intermediate transfer member 50, a cleaning device 63, and a static eliminator 64 are provided. Each single color image (black image, yellow image, magenta image, and cyan image) can be formed based on the color image information. The black image, the yellow image, the magenta image, and the cyan image formed in this manner are respectively transferred to the black electrostatic latent image carrier 10K on the intermediate transfer member 50 that is rotationally moved by the support rollers 14, 15 and 16. Black image formed on top, yellow image formed on electrostatic latent image carrier 10Y for yellow, magenta image formed on electrostatic latent image carrier 10M for magenta, and electrostatic latent image carrier for cyan The cyan image formed on 10C is sequentially transferred (primary transfer). Then, the black image, the yellow image, the magenta image, and the cyan image are superimposed on the intermediate transfer member 50 to form a composite color image (color transfer image).

  On the other hand, in the paper feed table 200, one of the paper feed rollers 142 is selectively rotated to feed out a sheet (recording paper) from one of the paper feed cassettes 144 provided in multiple stages in the paper bank 143. Each sheet is separated and sent to the paper feed path 146, transported by the transport roller 147, guided to the paper feed path 148 in the copying machine main body 150, and abutted against the registration roller 49 and stopped. Alternatively, the sheet feed roller 142 is rotated to feed out sheets (recording paper) on the manual feed tray 54, separated one by one by the separation roller 145, put into the manual feed path 53, and abutted against the registration roller 49 and stopped. . The registration roller 49 is generally used while being grounded, but may be used in a state where a bias is applied to remove paper dust from the sheet. Then, the registration roller 49 is rotated in synchronization with the synthesized color image (color transfer image) synthesized on the intermediate transfer member 50, and a sheet (recording paper) is interposed between the intermediate transfer member 50 and the secondary transfer device 22. The secondary color transfer device 22 transfers the composite color image (color transfer image) onto the sheet (recording paper), thereby transferring the color image onto the sheet (recording paper). Is formed. The residual toner on the intermediate transfer member 50 after image transfer is cleaned by the intermediate transfer member cleaning device 17.

  The sheet (recording paper) on which the color image has been transferred is conveyed by the secondary transfer device 22 and sent to the fixing device 25, where the combined color image (by the heat and pressure) A color transfer image) is fixed on the sheet (recording paper). Thereafter, the sheet (recording paper) is switched by the switching claw 55 and discharged by the discharge roller 56 and stacked on the discharge tray 57, or switched by the switching claw 55 and reversed by the sheet reversing device 28 and transferred again. After being guided to the position and recording an image on the back surface, the image is discharged by the discharge roller 56 and stacked on the discharge tray 57.

  The image forming method and the image forming apparatus of the present invention can stabilize the toner fluidity while improving the fixing releasability, and the pulverization of the present invention excellent in chargeability, transportability, and releasability. Since the toner is used, the fluidity of the toner is stabilized over a long period of time, halftone blurring (halftone unevenness) and white spots can be prevented, and a high-quality image can be stably obtained.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Synthesis Example 1)
-Synthesis of first binder resin-
As a vinyl monomer, 600 g of styrene, 110 g of butyl acrylate, 30 g of acrylic acid, and 30 g of dicumyl peroxide as a polymerization initiator were placed in a dropping funnel.
Among polyester monomers, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane 1230 g, polyoxyethylene (2.2) -2,2-bis (4- 290 g of hydroxyphenyl) propane, 250 g of isododecenyl succinic anhydride as a carboxylic acid component, 310 g of terephthalic acid, 180 g of 1,2,4-benzenetricarboxylic anhydride, 7 g of dibutyltin oxide as an esterification catalyst, and paraffin wax (melting point 75.75). 325 g (10.5 parts by mass with respect to 100 parts by mass of charged monomer) at 0 ° C., the half-value width of the endothermic peak at the time of temperature rise measured by a differential scanning calorimeter is 4 ° C., thermometer, stainless steel stirrer, Enters a 5-liter four-necked flask equipped with a flow-down condenser and a nitrogen inlet tube , Under a nitrogen atmosphere in a heating mantle while stirring at a temperature of 160 ° C., it was added dropwise over one hour a mixture of the vinyl monomer resins and the polymerization initiator from the dropping funnel. The addition polymerization reaction was aged for 2 hours while maintaining the temperature at 160 ° C., and then the temperature was raised to 230 ° C. to perform the condensation polymerization reaction. The degree of polymerization was tracked by the softening point measured using a constant load extrusion capillary rheometer, and when the desired softening point was reached, the reaction was terminated to synthesize the first binder resin.
The softening point of the obtained first binder resin was 130 ° C.

(Synthesis Example 2)
-Synthesis of second binder resin-
Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane (2210 g) as a polyol, terephthalic acid (850 g), 1,2,4-benzenetricarboxylic anhydride (120 g), and esterification catalyst as a carboxylic acid component Dibutyltin oxide 0.5g was put into a 5 liter four-necked flask equipped with a thermometer, a stainless steel stirrer, a flow-down condenser and a nitrogen inlet tube, and the temperature was reduced to 230 ° C under a nitrogen atmosphere in a mantle heater. A polymerization reaction was performed. The degree of polymerization was tracked by the softening point measured using a constant load extrusion type capillary rheometer, and when the desired softening point was reached, the reaction was terminated and a second binder resin was synthesized.
The softening point of the obtained second binder resin was 115 ° C.

(Production Example 1)
-Production of colored particles 1-
HNP-10 as a wax (100 parts by mass of the first and second binder resins (36.9 parts by mass of the first binder resin, 63.1 parts by mass of the second binder resin)) Nippon Seiwa Co., Ltd.) 3.6 parts by mass, C.I. I. A master batch containing 4 parts by weight of Pigment Red 57: 1 is thoroughly mixed with a Henschel mixer, and then a uniaxial extrusion kneader (KCK42 type, manufactured by Asada Tekko Co., Ltd.) is used as a mortar mold with a fixed disk and a rotating disk. The mixture was melt-kneaded under the conditions of a throughput of 80 kg / h and a kneading temperature of 100 ° C. The obtained kneaded material was rolled to a thickness of 2 mm with a cooling press roller, cooled with a cooling belt, and then coarsely pulverized with a feather mill (manufactured by Hosokawa Micron Corporation). Then, it grind | pulverized to the average particle diameter of 10 micrometers-12 micrometers with the mechanical grinder (KTM, Kawasaki Heavy Industries, Ltd. make). Next, after pulverizing with coarse particle classification with a jet pulverizer (IDS, manufactured by Nippon Pneumatic Industrial Co., Ltd.), the fine powder classification is performed using a rotor type classifier (teaplex type classifier type, 100ATP, manufactured by Hosokawa Micron Corporation). Then, classification was performed to prepare colored particles 1.

(Production Examples 2 to 8)
-Preparation of colored particles 2-8-
In Production Example 1, the colored particles 2 to 8 were added in the same manner as in Production Example 1 except that the addition amount of the first binder resin and the second binder resin and the type of wax were changed as shown in Table 1. Produced.

  About each obtained colored particle, the volume average particle diameter was measured as follows. The results are shown in Table 1.

<Volume average particle diameter of colored particles>
The volume average particle diameter of the colored particles was measured using a particle size distribution measuring apparatus (Coulter Counter TA-II or Coulter Multisizer II, manufactured by Coulter, Inc.) by a Coulter counter method.
First, 0.1 to 5 ml of a surfactant (alkyl benzene sulfonate) is added as a dispersant to 100 to 150 ml of an electrolytic aqueous solution. Here, the electrolytic solution is prepared by preparing a 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 as a solid content. The electrolyte in which the sample is suspended is subjected to a dispersion treatment for 1 to 3 minutes with an ultrasonic disperser, and the volume and number of colored particles are measured with the measuring device using a 100 μm aperture as an aperture. The number distribution was calculated and the volume average particle size of the colored particles was determined.
As a channel, it is 2.00 micrometers or more and less than 2.52 micrometers; 2.52 micrometers or more and less than 3.17 micrometers; 3.17 micrometers or more and less than 4.00 micrometers; 4.00 micrometers or more and less than 5.04 micrometers; 5.04 micrometers or more and less than 6.35 micrometers; .35 μm or more and less than 8.00 μm; 8.00 μm or more and less than 10.08 μm; 10.08 μm or more and less than 12.70 μm; 12.70 μm or more and less than 16.00 μm; 16.00 μm or more and less than 20.20 μm; Less than 40 μm; 25.40 μm or more and less than 32.00 μm; 3 channels of 32.00 μm or more and less than 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.

-Wax-
* HNP-10: Nippon Seiwa Co., Ltd., melting point 75 ° C.
* HNP-3: Nippon Seiwa Co., Ltd., melting point 64 ° C.
* 135: Nippon Seiwa Co., Ltd., melting point: 58 ° C
* FT-100: Nippon Seiwa Co., Ltd., melting point 98 ° C.

(Examples 1-10 and Comparative Examples 1-6)
-Magenta toner production-
With respect to 100 parts by mass of the produced colored particles 1 to 8, large-diameter particles shown in Table 2 were immobilized with a powder processing apparatus. Thereafter, the small-diameter particles shown in Table 2 were mixed with a Henschel mixer at 35 m / s for 5 minutes to produce magenta toners of Examples 1 to 10 and Comparative Examples 1 to 6.
FIG. 7 shows a scanning electron microscope (SEM) photograph of the toner of Example 5. From the SEM photograph of FIG. 7, it was found that silica having a primary average particle size of about 100 nm was uniformly dispersed and fixed to the toner base.

-Silica particles-
* X-24: Shin-Etsu Chemical Co., Ltd., primary particle size 100 nm
* EP-BR0412: CAB-O-SIL, primary particle size 150 nm
* EP-BR0401: CAB-O-SIL, primary particle size 200 nm
* EP-BR0405: CAB-O-SIL, primary particle size 230 nm
* RX-50: Nippon Aerosil Co., Ltd., primary particle size 40 nm
* R972: Nippon Aerosil Co., Ltd., primary particle size 16 nm
* NAX50: Nippon Aerosil Co., Ltd., primary particle size 30 nm
* TG-811F: CAB-O-SIL, primary particle size 9 nm
-Powder processing equipment-
* Nobilta: manufactured by Hosokawa Micron Co., Ltd. 150 g of toner is charged into a 300 cc processing tank, and the rotational speed is adjusted so that the load power is 2.8 to 3.0 kW, so that the load power is 2.8 to 3.0 kW. Then, the process was continued for 30 seconds and finished.
* Ong mill: manufactured by Hosokawa Micron Corporation As shown in FIG. 6A, the ong mill rotated the casing 1 at a high speed and pressed the toner and large-diameter silica particles in the casing 1 against the inner wall of the casing 1 by the centrifugal force. Next, as shown in FIG. 6B, the pressed toner particles and large-diameter silica particles 2 are passed between the meniscus 3 slightly narrower than the layer of the toner particles and large-diameter silica particles 2 and the inner wall of the casing 1. Thus, the resin on the surfaces of the toner particles and the large-diameter silica particles 2 is melted by the frictional heat generated by the pressing force at the time of passing, so that the large-diameter silica particles are fused to the surfaces of the toner particles 2. Thus, the toner particles and the large-diameter silica particles 2 in which the large-diameter silica particles are fused to the surface are scraped off from the inner wall of the casing 1 by the scraping member 4. Then, the rotation of the casing 1 was adjusted so that the frictional heat due to the pressing force at the time of passing was about 50 ° C., and 200 g of the toner particles and the large-diameter silica particles 2 were treated for 3 minutes.

  Next, various characteristics were evaluated for each of the produced magenta toners as follows. The results are shown in Tables 3 and 4.

<Adhesion strength of large particles>
The adhesion strength of the large-diameter particles is obtained by adding 2 g of toner to 30 ml of a 10-fold diluted surfactant solution and sufficiently blending in, and then applying energy at 40 W for 1 minute using an ultrasonic homogenizer, The particles were separated, washed and then dried. A toner pellet is prepared by applying a force of 1 N / cm ^{2 to 2} g of the treated toner and untreated toner for 60 seconds, respectively, and using a wavelength dispersive X-ray fluorescence analyzer (XRF1700, manufactured by Shimadzu Corporation). The adhesion amount of large-sized particles before and after treatment (for example, silicon in the case of silica) was quantified by a calibration curve method, and the ratio of the adhesion amount before and after treatment was calculated.

<Surface abundance of primary particles and primary particle size>
Using a scanning electron microscope (SEM), the number of particles having a primary particle diameter of 50 nm or more was counted for 30 fields of view at 20,000 magnifications. The count number was converted per toner unit area of 1 μm ² to calculate the toner surface average abundance of large diameter particles.
In addition, using a scanning electron microscope (SEM), the number of particles having a primary particle diameter of 50 nm or more was measured for 30 fields by observation at a magnification of 20,000, and the primary particle diameter was calculated. At this time, the primary particle diameter is in the range of 80 nm to 200 nm, and in the present invention, it is defined as including large diameter particles of 80 nm to 200 nm.

<Surface exposure amount of toner adhesive component>
As for the surface exposure amount of the toner adhesive component, 1.0 g of toner and 10 mL of hexane were placed in a glass container, dipped for 10 minutes, filtered, and the amount of residue after drying the filtrate was measured.

<Total amount of toner adhesive component>
The total amount of the adhesive component of the toner was a sample that was heated to 200 ° C. using a differential scanning calorimeter (DSC6200, manufactured by Seiko Instruments Inc.) and then cooled to 0 ° C. at a temperature decreasing rate of 10 ° C./min. Was measured at a heating rate of 10 ° C./min, and was determined from the area surrounded by the intersection of the tangent line from the high temperature side and the endothermic peak portion of the low temperature side.

<Maximum endothermic peak of toner>
The maximum endothermic peak of the toner is raised to 200 ° C. using a differential scanning calorimeter (DSC6200, manufactured by Seiko Instruments Inc.), and the sample cooled to 0 ° C. at a temperature lowering rate of 10 ° C./min. The maximum endothermic temperature when measured at a temperature rate of 10 ° C./min was determined as the maximum endothermic peak of the toner.

<Image evaluation>
Image evaluation was performed as follows using a color laser printer (IPSIO CX2500, manufactured by Ricoh Co., Ltd.).
-Bosotsuki-
Under the environment of 25 ° C. and 50% RH, the back side of the half-tone double-sided printing after 2,000 sheets of actual machine durability was continuously observed for 2% of the total area ratio to be developed was visually observed, and the following criteria It was evaluated with.
〔Evaluation criteria〕
◎: No blurring ○: No quality problems ×: Quality problems-white spots-
The white spots on the photoreceptor were visually observed when 2,000 sheets were run by a method of printing one image of 1% of the total area ratio to be developed in one job, and evaluated according to the following criteria.
〔Evaluation criteria〕
◎: No white spots ○: No quality problem ×: Quality problem

The pulverized toner of the present invention can stabilize the toner fluidity while improving the fixing releasability, and is excellent in chargeability, transportability, and releasability. It is suitably used for developing a latent image formed in a method, an electrostatic printing method, or the like.
Since the image forming apparatus, the image forming method, and the process cartridge of the present invention use the pulverized toner of the present invention and can form an extremely high quality image, for example, a laser printer, a direct digital plate making machine, Or, it can be widely used in full-color copying machines, full-color laser printers, full-color plain paper fax machines and the like using an indirect electrophotographic multicolor image development system.

FIG. 1 is a schematic configuration diagram showing an example of a process cartridge used in the present invention. FIG. 2 is a schematic explanatory view showing an example of carrying out the image forming method of the present invention by the image forming apparatus. FIG. 3 is a schematic explanatory view showing another example in which the image forming method of the present invention is carried out by the image forming apparatus. FIG. 4 is a schematic explanatory diagram showing an example in which the image forming method of the present invention is carried out by an image forming apparatus (tandem color image forming apparatus). FIG. 5 is a partially enlarged schematic explanatory view of the image forming apparatus shown in FIG. FIG. 6A is a schematic view of an ang mill used in the examples. FIG. 6B is an enlarged view of FIG. 6A. FIG. 7 is an SEM photograph of the toner of Example 5. FIG. 8 is a schematic view showing an example of a developing unit in the image forming apparatus of the present invention.

Explanation of symbols

10 Electrostatic latent image carrier (photosensitive drum)
10K Electrostatic latent image carrier for black 10Y Electrostatic latent image carrier for yellow 10M Electrostatic latent image carrier for magenta 10C Electrostatic latent image carrier for cyan 14 Support roller 15 Support roller 16 Support roller 17 Intermediate transfer cleaning device DESCRIPTION OF SYMBOLS 18 Image forming means 20 Charging roller 21 Exposure device 22 Secondary transfer device 23 Roller 24 Secondary transfer belt 25 Fixing device 26 Fixing belt 27 Pressure belt 28 Sheet reversing device 30 Exposure device 32 Contact glass 33 First traveling body 34 Second Traveling body 35 Imaging lens 36 Reading sensor 40 Developing device 41 Developing belt 42K Developer container 42Y Developer container 42M Developer container 42C Developer container 43K Developer supply roller 43Y Developer supply roller 43M Developer supply roller 43C Developer supply roller 44K Development roller La 44Y Development roller 44M Development roller 44C Development roller 45K Black development unit 45Y Yellow development unit 45M Magenta development unit 45C Cyan development unit 49 Registration roller 50 Intermediate transfer member 51 Roller 52 Separation roller 53 Manual feed path 54 Manual feed tray 55 Switching Claw 56 Discharge Roller 57 Discharge Tray 58 Corona Charger 60 Cleaning Device 61 Developer 62 Transfer Charger 63 Photoconductor Cleaning Device 64 Charger 70 Charger Lamp 80 Transfer Roller 90 Cleaning Device 95 Transfer Paper 100 Image Forming Device 101 Electrostatic Latent image carrier (photoconductor)
DESCRIPTION OF SYMBOLS 102 Charging means 103 Exposure 104 Developing means 105 Recording medium 107 Cleaning means 108 Transfer means 110 Carrier processing tank 112 Raw material recovery tank 113 Carbon dioxide cylinder 114 Stirrer 115 Stirrer 116 Entrainer tank 117 Cooling jacket 118 Temperature control jacket 120 Tandem developer 121 Heating roller 122 Fixing roller 123 Fixing belt 124 Pressure roller 125 Heating source 126 Cleaning roller 127 Temperature sensor 130 Document table 142 Paper feed roller 143 Paper bank 144 Paper feed cassette 145 Separating roller 146 Paper feed path 147 Transport roller 148 Paper feed path 150 Copier Main Body 160 Charging Device 200 Paper Feed Table 300 Scanner 400 Automatic Document Feeder (ADF)

Claims (7)

A toner including a toner base containing at least a colorant, a binder resin, and a release agent, and inorganic fine particles,
The inorganic fine particles include large particles having a primary particle size of 80 nm to 200 nm, and the large particles adhere to the toner base with an adhesion strength of 50% to 85%;
The maximum endothermic peak of the toner measured by a differential scanning calorimeter (DSC) is 60 ° C. to 90 ° C., and the surface exposure amount of the adhesive component in the toner is 11 mg / g to 24 mg / g. To grind toner.   The pulverized toner according to claim 1, wherein the large-diameter particles are silica, and the total amount of adhesive components in the toner is 4.0 mj / mg to 6.0 mj / mg. 3. The pulverized toner according to claim 1, wherein the toner particles on the surface of the large diameter particles are 5 / μm ² to 10 / μm ² .   The pulverized toner according to any one of claims 1 to 3, wherein the inorganic fine particles include small-diameter particles having a primary particle diameter of 7 nm to 30 nm, and a total amount of the inorganic fine particles is 3.0% by mass to 5.0% by mass.   An electrostatic latent image carrier and a developing unit that develops the electrostatic latent image formed on the electrostatic latent image carrier using the pulverized toner according to claim 1 to form a visible image. And a process cartridge.   An electrostatic latent image forming step for forming an electrostatic latent image on the electrostatic latent image carrier, and the electrostatic latent image is developed using the pulverized toner according to claim 1 and visible. An image forming method comprising: a developing step for forming an image; a transfer step for transferring the visible image to a recording medium; and a fixing step for fixing the transferred image transferred to the recording medium.   The electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, and grinding the electrostatic latent image according to any one of claims 1 to 4. At least development means for forming a visible image by developing with toner, transfer means for transferring the visible image to a recording medium, and fixing means for fixing the transferred image transferred to the recording medium An image forming apparatus.