JP2010230733A - Toner manufacturing method, toner, two-component developer, developing device, and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner manufacturing method that prevents an external additive from being separated from a toner surface and has excellent transfer efficiency for a long time, and to provide the toner produced by the method, a two-component developer which includes the toner and whose charge amount is hardly reduced, a developing device using the two-component developer, and an image forming device. <P>SOLUTION: Surfaces of toner mother particles are coated with resin particles of 0.05 to 1 μm, impact force is applied while a plasticizing liquid is sprayed to form a coated layer comprising the resin particles while concave parts remain on the surface, and then fixed impact force is applied to spacer particles of 40 to 300 nm toward the surface concave parts while the plasticizing liquid is sprayed, to fix the spacer particles to the coated layer in a semi-buried state. The two-component developer including the toner thus produced is filled in the developing device of the image forming device to form an image. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a toner production method, a toner, a two-component developer containing the toner, a developing device and an image forming apparatus using the two-component developer.

  An image forming apparatus using an electrostatic electrophotographic system includes, for example, charging, exposure, development, transfer, peeling, cleaning, static elimination, and fixing processes. As a specific image forming method including these steps, first, the surface of a rotating photosensitive member is uniformly charged by a charging device, and the charged photosensitive member surface is irradiated with laser light from an exposure device to perform photosensitive processing. An electrostatic latent image is formed on the body surface. Subsequently, a toner image is formed by a developing device on the surface of the photoreceptor on which the electrostatic latent image has been developed. The toner image on the surface of the photoreceptor is transferred to a recording medium by a transfer device, and then the toner image is fixed to the recording medium by heating with a fixing device. The transfer residual toner remaining on the surface of the photoconductor is removed by a cleaning device and collected by a predetermined collecting unit, and the remaining charge is removed from the cleaned photoconductor surface by a static eliminator to prepare for the next image formation.

  In recent years, a toner having a volume average particle diameter of 7 μm or less has become the mainstream in order to increase the image reproducibility of the image forming apparatus and improve the dot reproducibility. The toner having a small particle diameter has a higher cohesion and adhesion than a toner having a large particle diameter, and there is a problem that transfer efficiency is lowered when transferring from a photoreceptor to a recording medium. To solve such a problem, Patent Document 1 discloses a toner that solves a decrease in transfer efficiency by externally adding a large particle size external additive to the toner surface.

JP 2000-81723 A

  Here, when a toner to which an external additive having a large particle diameter is externally added is used as a two-component developer together with a resin-coated carrier whose surface is coated with a resin, there is a problem that the charge amount of the toner gradually decreases. As a result of examining the cause, an external additive having a number average particle size in the range of 40 to 80 nm tends to be detached from the toner surface, and when stirred for a long time in the developing tank, the external additive is added to the resin layer on the surface of the resin-coated carrier. The agent was found to be easily buried (accumulated). FIG. 9 is a cross-sectional view schematically showing a state in which the external additive 5 a is buried in the resin layer 8 on the surface of the resin-coated carrier 6. When the external additive 5 a is buried, innumerable irregularities are formed on the surface of the resin-coated carrier 6, and the ability of the resin-coated carrier 6 to frictionally charge the newly supplied toner 1 is lowered. Patent Document 1 also includes a configuration using an external additive having a number average particle size in the range of 40 to 80 nm, but no measures are taken to make it difficult for such an external additive to be detached from the toner surface. Then, there is a problem that the charge amount of the toner gradually decreases.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a toner production method in which an external additive is not easily detached from the toner surface and is excellent in transfer efficiency over a long period of time, a toner produced by the production method, the toner, and the charge amount of the toner And a developing device and an image forming apparatus using the two-component developer.

The present invention provides a first mixing step in which toner base particles and resin particles having an average primary particle size of 0.05 μm or more and 1 μm or less are mixed to attach the resin particles to the surface of the toner base particles to obtain a resin particle-attached toner. When,
Rotating stirring means for generating a circulating air flow, a rotating stirring chamber for storing the rotating stirring means, a circulation pipe connected to the rotating stirring chamber, and at least part of a powder flow path including the rotating stirring chamber and the circulation pipe Temperature adjusting means for adjusting the temperature in the rotary stirring means and the powder flow path to a predetermined temperature, and a plasticizing liquid provided in the circulation pipe for plasticizing the toner mother particles and the resin particles toward the circulation pipe. A rotary stirring device including a spraying means for spraying, applying an impact force to the toner adhering to the resin particles, adjusting the temperature in the rotary stirring means and the powder flow path to a predetermined temperature by the temperature adjusting means, and spraying means By spraying the plasticizing liquid toward the inside of the circulation pipe, the resin particles adhering to the resin particle adhesion toner are fused, and the BET specific surface area is 0.9 m ² / g or more and 1.8 m ² / g or less. A resin coating A film forming step for obtaining toner;
A second mixing step of mixing the resin-coated toner and spacer particles having an average primary particle diameter of 40 nm or more and 300 nm or less to attach the spacer particles to the surface of the resin-coated toner to obtain a spacer particle-attached toner;
Using the rotary stirring device, the temperature adjusting means adjusts the temperature in the rotary stirring means and the powder flow path to a predetermined temperature, and the spraying means sprays the plasticizing liquid toward the inside of the circulation pipe, thereby adhering spacer particles. And a spacer particle fixing step of fixing spacer particles adhering to the toner.

  Further, the invention is characterized in that the spraying means includes a liquid feeding pump, and the plasticizing liquid at a constant flow rate is sprayed toward the inside of the circulation pipe by the liquid feeding pump.

  Further, the present invention is characterized in that the rotary stirring device includes a mechanism for discharging the plasticized liquid gasified in the powder flow path to the outside of the device at a constant concentration.

  Further, the present invention is characterized in that the plasticizing liquid contains alcohol, and the boiling point of the alcohol is not less than a temperature 20 ° C. lower than the glass transition temperature of the resin particles and not more than 20 ° C. higher than the glass transition temperature of the resin particles. To do.

  The present invention also provides a toner manufactured by the toner manufacturing method.

The present invention also provides a two-component developer comprising the toner and a carrier.
In addition, the present invention is a developing device that performs development using the two-component developer.

The present invention also provides an image carrier on which a latent image is formed,
A latent image forming means for forming a latent image on the image carrier;
An image forming apparatus comprising the developing device.

According to the present invention, the toner manufacturing method includes a first mixing step, a coating step, a second mixing step, and a spacer particle fixing step. Since the BET specific surface area of the resin-coated toner obtained in the coating step is 0.9 m ² / g or more and 1.8 m ² / g or less, the spacer particles can be stably stabilized in the semi-buried state in the spacer particle fixing step. Since the toner particles can be fixed, it is possible to produce a toner in which spacer particles are not easily detached from the toner surface. As a result, the spacer effect of the spacer particles can be stably obtained over a long period of time. Examples of the spacer effect include developability, transferability, cleaning properties by reducing adhesion between the toner and between the toner and the member, and maintenance of toner performance by suppressing the embedding of the small particle size external additive. When such a toner is used, transfer efficiency can be improved and carrier contamination due to photoconductor filming or detached spacer particles can be prevented.

  By using resin particles having an average primary particle diameter of 0.05 μm or more and 1 μm or less in the first mixing step, irregularities of an appropriate size can be formed on the surface, so that the BET specific surface area of the resin-coated toner is in the above range. In addition, it is possible to obtain a resin-coated toner in which the spacer particles can be stably fixed in a semi-buried state in the coating step.

  In the film forming step, a rotary stirrer including a rotary stirrer, a rotary stirrer chamber, a circulation pipe, a temperature adjuster, and a sprayer is used. The plastic coating liquid is sprayed toward the inside of the circulation pipe by the spraying means, but the resin coating is obtained by adjusting the temperature in the rotary stirring means and the powder flow path to a predetermined temperature and spraying the plasticizing liquid. The BET specific surface area of the toner can be in the above range, and a resin-coated toner that can stably fix the spacer particles in a semi-buried state in the coating step can be obtained.

  By using spacer particles having an average primary particle diameter of 40 nm or more and 300 nm or less in the second mixing step, the spacer particles can be stably fixed in a semi-buried state in the coating step.

  In the spacer particle fixing step, the temperature adjusting means adjusts the temperature in the rotary agitating means and the powder flow path to a predetermined temperature, and the spraying means sprays the plasticizing liquid into the circulation pipe to thereby form the spacer particles. It can be stably fixed in a semi-buried state.

  According to the invention, the spraying means includes the liquid feed pump, and a constant flow rate of the plasticizing liquid is sprayed toward the inside of the circulation pipe by the liquid feed pump. As a result, the plasticizing liquid can be gasified so as to have a constant concentration in the powder flow path, so that the concentration of the plasticizing liquid in the powder flow path is stable, and condensation and resin due to a sudden rise in liquid concentration Aggregation of particle-adhered toner and spacer particle-adhered toners and adhesion of these toner particles into the powder flow path can be prevented, and the yield of the toner can be improved.

  Further, according to the present invention, the rotary stirring device includes a mechanism for discharging the plasticized liquid gasified in the powder channel to the outside of the device, so that the liquid gas concentration in the powder channel is kept constant, It is possible to increase the drying speed of the plasticizing liquid, and to prevent the adhesion of the resin particle-adhering toner and the spacer particle-adhering toner in which the undried plasticizing liquid remains. Therefore, aggregation of these toner particles can be prevented, and the toner yield can be improved.

  According to the present invention, the plasticizing liquid contains alcohol, and the boiling point of the alcohol is 20 ° C. lower than the glass transition temperature of the resin particles and 20 ° C. higher than the glass transition temperature of the resin particles. Since the resin contained in the toner has low solubility and quickly volatilizes around the glass transition temperature of the resin particles, it is possible to effectively suppress the temperature rise of the resin particle-adhered toner more than necessary, and the BET specific surface area of the resin-coated toner can be reduced. A desired range can be obtained. In addition, since such alcohol has a low viscosity and the spray droplet diameter of the plasticizing liquid sprayed from the spraying means does not become coarse, it is possible to spray a plasticizing liquid with a uniform spray droplet diameter. Become. Furthermore, since the vapor pressure is high, the sprayed plasticizing liquid can be easily removed and dried. As a result, it is possible to obtain a resin-coated toner and toner in which the coating amount of the resin particles and the spacer particles is uniform.

  According to the invention, the toner is produced by the toner production method of the invention. In the toner manufacturing method of the present invention, the spacer particles can be stably fixed in a semi-embedded state, and therefore, the toner manufactured by the toner manufacturing method of the present invention is unlikely to be detached from the surface. When an image is formed using such a toner, fogging and toner scattering are unlikely to occur over a long period of time, so that a high-definition and good-quality image with no density unevenness can be stably formed.

  According to the invention, the two-component developer includes the toner of the invention and a carrier. In the toner of the present invention, since the spacer particles are not easily detached from the surface, it is possible to prevent photoconductor filming and carrier contamination due to the detached spacer particles. Therefore, since the decrease in the toner charging ability of the carrier can be suppressed, it is possible to stably form a high-definition and good-quality image with no density unevenness over a long period of time without fogging and toner scattering. it can.

  According to the invention, the developing device performs development using the two-component developer of the invention. The two-component developer of the present invention can suppress a decrease in the toner charging ability of the carrier and can prevent filming of the photoreceptor, so that a high-definition and good toner image without uneven density can be stably formed on the photoreceptor. be able to.

  Further, according to the present invention, since the image forming apparatus includes the developing device of the present invention, it is possible to stably form a high-definition image having good image quality without uneven density over a long period of time.

6 is a flowchart illustrating an example of a procedure of a toner manufacturing method according to the exemplary embodiment. FIG. 3 is a front view showing a configuration of a rotary stirring device 201 used in the toner manufacturing method according to the present embodiment. It is the schematic sectional drawing which looked at the rotary stirring apparatus 201 shown in FIG. 2 from cut surface line A200-A200. FIG. 3 is a front view schematically showing a configuration around a powder input unit 206 and a powder recovery unit 207. FIG. 3 is a conceptual cross-sectional view showing the adhesion state of spacer particles 5 and external additive 4 at the initial stage of toner particles 1 contained in the toner of the present embodiment. FIG. 3 is a conceptual cross-sectional view showing the adhesion state of spacer particles 5 and external additive 4 over time with toner particles 1 of the present embodiment. It is sectional drawing which shows typically the structure of the image forming apparatus 100 which is the 4th Embodiment of this invention. FIG. 8 is a schematic diagram schematically illustrating a developing device 14 provided in the image forming apparatus 100 illustrated in FIG. 7. It is sectional drawing which shows typically the state by which the external additive 5a was embed | buried under the resin layer 8 of the resin coating carrier 6 surface.

1. Toner Manufacturing Method In the toner manufacturing method according to the first embodiment of the present invention, a toner in which spacer particles are semi-embedded in a resin-coated toner having a coating layer formed on the surface of toner base particles is manufactured. FIG. 1 is a flowchart illustrating an example of a procedure of a toner manufacturing method according to the present exemplary embodiment. The toner manufacturing method of the present embodiment includes a toner base particle preparation step S1, a resin particle preparation step S2, a resin coating toner preparation step S3, and a spacer particle semi-embedding step S4.

The resin-coated toner is obtained in the resin-coated toner preparation step S3, and the BET specific surface area of the resin-coated toner is 0.9 m ² / g or more and 1.8 m ² / g or less. Thereby, in the spacer particle semi-embedding step S4, the spacer particles can be stably fixed in the semi-buried state, and the toner in which the spacer particles are not easily detached from the toner surface can be manufactured. It can be obtained stably over a long period of time. Examples of the spacer effect include developability, transferability, cleaning properties by reducing adhesion between the toner and between the toner and the member, and maintenance of toner performance by suppressing the embedding of the small particle size external additive.

(1) Toner Base Particle Preparation Step In the toner base particle preparation step in step S1, toner base particles to be coated with the coating layer are prepared. The toner base particles are particles containing a binder resin and a colorant, and the production method thereof is not particularly limited and can be obtained by a known method. Examples of the method for producing the toner base particles include dry methods such as a pulverization method, and wet methods such as a suspension polymerization method, an emulsion aggregation method, a dispersion polymerization method, a dissolution suspension method, and a melt emulsification method. Hereinafter, a method for producing toner base particles by a pulverization method will be described.

(Method for preparing toner mother particles by pulverization method)
In the method for preparing toner base particles using the pulverization method, the toner base particle raw materials containing a binder resin, a colorant and other additives are dry-mixed with a mixer and then melt-kneaded with a kneader. The kneaded product obtained by melt kneading is cooled and solidified, and the solidified product cooled and solidified is pulverized by a pulverizer. Thereafter, particle size adjustment such as classification is performed as necessary to obtain toner mother particles.

  Known mixers can be used, such as Henschel mixer (trade name, manufactured by Mitsui Mining Co., Ltd.), super mixer (trade name, manufactured by Kawata Co., Ltd.), Mechano Mill (trade name, manufactured by Okada Seiko Co., Ltd.), etc. Henschel type mixing device, ong mill (trade name, manufactured by Hosokawa Micron Corporation), hybridization system (trade name, manufactured by Nara Machinery Co., Ltd.), Cosmo system (trade name, manufactured by Kawasaki Heavy Industries, Ltd.), and the like.

  As the kneading machine, a known kneading machine can be used. For example, a general kneading machine such as a twin-screw extruder, a triple roll, a lab blast mill can be used. More specifically, for example, TEM-100B (trade name, manufactured by Toshiba Machine Co., Ltd.), PCM-65 / 87, PCM-30 (all of which are trade names, manufactured by Ikegai Co., Ltd.), etc. Extruder, Needex (trade name, manufactured by Mitsui Mining Co., Ltd.) and other open roll type kneaders. Among these, an open roll type kneader is preferable.

  As the pulverizer, for example, a jet type pulverizer that pulverizes using a supersonic jet stream, and a solidified material in a space formed between a rotor (rotor) and a stator (liner) that rotate at high speed. An impact pulverizer that introduces and pulverizes can be used.

  For the classification, a known classifier capable of removing the excessively pulverized toner base particles by classification by centrifugal force and classification by wind force can be used. For example, a swirl wind classifier (rotary wind classifier) or the like is used. be able to.

(Toner base material)
As described above, the toner base particles include a binder resin and a colorant. The binder resin is not particularly limited, and a known binder resin for black toner or a known binder resin for color toner can be used. For example, polystyrene, styrene-acrylic acid ester copolymer can be used. Examples thereof include styrene resins such as polymerization resins, acrylic resins such as polymethyl methacrylate, polyolefin resins such as polyethylene, polyesters, polyurethanes, and epoxy resins. Moreover, you may use resin obtained by mixing a raw material monomer mixture with a mold release agent and performing a polymerization reaction. Binder resin can be used individually by 1 type, or can use 2 or more types together.

  Among these binder resins, polyester is excellent in transparency and can impart good powder fluidity, low-temperature fixability, secondary color reproducibility, etc. to toner particles, and is therefore suitable as a binder resin for color toners. It is. Known polyesters can be used, and examples thereof include polycondensates of polybasic acids and polyhydric alcohols.

  As the polybasic acid, those known as polyester monomers can be used, for example, terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid, naphthalenedicarboxylic acid and other aromatic carboxylic acids, maleic anhydride, Examples thereof include aliphatic carboxylic acids such as fumaric acid, succinic acid, alkenyl succinic anhydride, and adipic acid, and methyl esterified products of these polybasic acids. A polybasic acid can be used individually by 1 type, or can use 2 or more types together.

  As the polyhydric alcohol, those known as monomers for polyesters can be used. For example, aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, hexanediol, neopentylglycol, glycerin, cyclohexanediol, cyclohexanediene, etc. Examples thereof include aromatic diols such as alicyclic polyhydric alcohols such as methanol and hydrogenated bisphenol A, ethylene oxide adducts of bisphenol A, and propylene oxide adducts of bisphenol A. A polyhydric alcohol can be used individually by 1 type, or can use 2 or more types together.

  The polycondensation reaction between the polybasic acid and the polyhydric alcohol can be carried out according to a conventional method. For example, the polycondensation reaction is performed by bringing the polybasic acid and the polyhydric alcohol into contact with each other in the presence of an organic solvent and a polycondensation catalyst. The process is terminated when the acid value, softening temperature, etc. of the polyester reach predetermined values. Thereby, polyester is obtained. In some cases, an organic solvent may not be used. When a methyl esterified product of a polybasic acid is used as a part of the polybasic acid, a demethanol polycondensation reaction is performed. In this polycondensation reaction, for example, the carboxyl group content at the end of the polyester can be adjusted by appropriately changing the mixing ratio of polybasic acid and polyhydric alcohol, the reaction rate, etc., and thus the properties of the resulting polyester are changed. be able to. When trimellitic anhydride is used as the polybasic acid, a carboxyl group can be easily introduced into the main chain of the polyester, and a modified polyester can be obtained.

  As the polyester resin, a self-dispersing polyester that exhibits self-dispersibility in water by bonding a hydrophilic group such as a carboxyl group or a sulfonic acid group to the main chain and / or side chain of the polyester can also be used. . A resin obtained by grafting polyester and acrylic resin can also be used.

  The binder resin preferably has a glass transition temperature of 30 ° C. or higher and 80 ° C. or lower. When the glass transition temperature of the binder resin is less than 30 ° C., blocking in which the toner thermally aggregates easily occurs in the image forming apparatus, and storage stability may be deteriorated. When the glass transition temperature of the binder resin exceeds 80 ° C., the fixability of the toner to the recording medium is lowered, and there is a possibility that fixing failure occurs.

  Examples of the colorant include black, yellow, orange, red, purple, blue, green and white colorants. Organic dyes, organic pigments, inorganic dyes, inorganic pigments and the like commonly used in the field of electrophotography Can be used.

  Examples of the black colorant include carbon black, copper oxide, manganese dioxide, aniline black, activated carbon, nonmagnetic ferrite, magnetic ferrite, and magnetite.

  Examples of yellow colorants include chrome lead, zinc yellow, cadmium yellow, yellow iron oxide, mineral fast yellow, nickel titanium yellow, navel yellow, naphthol yellow S, Hansa yellow G, Hansa yellow 10G, benzidine yellow G, and benzidine. Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG, Tartrazine Lake, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. Pigment yellow 138, C.I. I. Pigment yellow 180, C.I. I. And CI Pigment Yellow 185.

  Examples of the orange colorant include red chrome yellow, molybdenum orange, permanent orange GTR, pyrazolone orange, vulcan orange, indanthrene brilliant orange RK, benzidine orange G, indanthrene brilliant orange GK, C.I. I. Pigment orange 31, C.I. I. And CI Pigment Orange 43.

  Examples of red colorants include bengara, cadmium red, red lead, mercury sulfide, cadmium, permanent red 4R, risor red, pyrazolone red, watching red, calcium salt, lake red C, lake red D, and brilliant carmine 6B. Eosin Lake, Rhodamine Lake B, Alizarin Lake, Brilliant Carmine 3B, C.I. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 5, C.I. I. Pigment red 6, C.I. I. Pigment red 7, C.I. I. Pigment red 15, C.I. I. Pigment red 16, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 53: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 123, C.I. I. Pigment red 139, C.I. I. Pigment red 144, C.I. I. Pigment red 149, C.I. I. Pigment red 166, C.I. I. Pigment red 177, C.I. I. Pigment red 178, C.I. I. And CI Pigment Red 222.

  Examples of purple colorants include manganese purple, fast violet B, and methyl violet lake.

  Examples of blue colorants include bitumen, cobalt blue, alkali blue lake, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partially chlorinated products, first sky blue, induslen blue BC, C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 16, C.I. I. And CI Pigment Blue 60.

  Examples of the green colorant include chrome green, chromium oxide, pigment green B, micalite green lake, final yellow green G, C.I. I. And CI Pigment Green 7.

  Examples of the white colorant include compounds such as zinc white, titanium oxide, antimony white, and zinc sulfide.

  One colorant can be used alone, or two or more different colorants can be used in combination. Moreover, even if it is the same color, 2 or more types can be used together. The amount of the colorant used is not particularly limited, but is preferably 5 parts by weight or more and 20 parts by weight or less, more preferably 5 parts by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the binder resin.

  The colorant may be used as a master batch in order to uniformly disperse it in the binder resin. Two or more colorants may be used in the form of composite particles. The composite particles can be produced, for example, by adding an appropriate amount of water, lower alcohol or the like to two or more colorants, granulating with a general granulator such as a high speed mill, and drying. The master batch and the composite particles are mixed into the toner base particle raw material during dry mixing.

  The toner base particles may contain a charge control agent in addition to the binder resin and the colorant. As the charge control agent, a charge control agent for positive charge control and negative charge control commonly used in this field can be used.

  Examples of charge control agents for controlling positive charge include nigrosine dyes, basic dyes, quaternary ammonium salts, quaternary phosphonium salts, aminopyrines, pyrimidine compounds, polynuclear polyamino compounds, aminosilanes, nigrosine dyes and derivatives thereof, and triphenylmethane. Derivatives, guanidine salts, amidine salts and the like can be mentioned.

  Charge control agents for controlling negative charges include oil-soluble dyes such as oil black and spiron black, metal-containing azo compounds, azo complex dyes, metal salts of naphthenic acid, metal salts of salicylic acid and its derivatives (metals are metal Chromium, zinc, zirconium, etc.), boron compounds, fatty acid soaps, long-chain alkyl carboxylates, resin acid soaps, and the like. A charge control agent can be used individually by 1 type, or can use 2 or more types together as needed. The amount of the charge control agent used is not particularly limited and can be appropriately selected from a wide range, but is preferably 0.5 parts by weight or more and 3 parts by weight or less with respect to 100 parts by weight of the binder resin.

  Further, the toner base particles may contain a release agent in addition to the binder resin and the colorant. As the release agent, those commonly used in this field can be used, for example, petroleum wax such as paraffin wax and derivatives thereof, microcrystalline wax and derivatives thereof, Fischer-Tropsch wax and derivatives thereof, polyolefin wax (polyethylene wax, polypropylene Wax etc.) and derivatives thereof, low molecular weight polypropylin wax and derivatives thereof, hydrocarbon polymer waxes such as polyolefin polymer wax (low molecular weight polyethylene wax etc.) and derivatives thereof, carnauba wax and derivatives thereof, rice wax and derivatives thereof , Candelilla wax and its derivatives, plant wax such as wood wax, animal wax such as beeswax and whale wax, fatty acid amide, phenol fatty acid ester, etc. Oil-based synthetic waxes, long-chain carboxylic acids and their derivatives, long-chain alcohols and derivatives thereof, silicon-based polymers, such as higher fatty acids. Derivatives include oxides, block copolymers of vinyl monomers and waxes, graft modified products of vinyl monomers and waxes, and the like.

  The amount of the release agent used is not particularly limited and can be appropriately selected from a wide range, but is preferably 0.2 parts by weight or more and 20 parts by weight or less, more preferably 0.5 parts by weight or more with respect to 100 parts by weight of the binder resin. It is 10 parts by weight or less, particularly preferably 1.0 part by weight or more and 8.0 parts by weight or less.

(Toner mother particles)
The toner base particles obtained in the toner base particle preparation step S1 preferably have a volume average particle diameter of 4 μm or more and 8 μm or less. When the volume average particle diameter of the toner base particles is 4 μm or more and 8 μm or less, a high-definition image can be stably formed over a long period of time. Further, by reducing the particle size to this range, a high image density can be obtained even with a small amount of adhesion, and the toner consumption can be reduced. If the volume average particle size of the toner base particles is less than 4 μm, the particle size of the toner base particles becomes too small, and there is a possibility that high charge and low fluidity may occur. When this high charging and low fluidization occur, it becomes impossible to stably supply the toner to the photoreceptor, and there is a possibility that background fogging and a decrease in image density may occur. If the volume average particle diameter of the toner base particles exceeds 8 μm, it is desirable because the toner base particles have a large particle diameter, the layer thickness of the formed image becomes high, and an image with a remarkably graininess is obtained, and a high-definition image cannot be obtained. Absent. Further, as the toner base particle size increases, the specific surface area decreases and the toner charge amount decreases. When the charge amount of the toner is small, the toner is not stably supplied to the photoconductor, and there is a possibility that in-machine contamination due to toner scattering occurs.

(2) Resin Particle Preparation Step In the resin particle preparation step in step S2, dried resin particles are prepared. Any method may be used for drying the resin particles, and examples thereof include hot air heat receiving drying, conduction heat transfer drying, far-infrared drying, and microwave drying. The resin particles are used as a material for coating the surface of the toner base particles in the subsequent resin-coated toner production step S3. By coating the surface of the toner base particles with resin particles, for example, toner aggregation due to melting of a low melting point component such as a release agent contained in the toner base particles can be prevented during storage of the developer. Further, for example, when the toner base particles are coated by spraying a liquid in which resin particles are dispersed, the shape of the resin particles remains on the surface of the toner base particles, so that the toner has excellent cleaning properties compared to a toner having a smooth surface. Can be obtained.

  The resin particles can be obtained by, for example, emulsifying and dispersing a resin, which is a resin particle raw material, with a homogenizer or the like to make fine particles. It can also be obtained by polymerization of resin monomer components.

  As the resin used as the resin particle raw material, for example, a resin used as a toner base particle raw material can be used, and examples thereof include polyester, acrylic resin, styrene resin, and styrene-acrylic copolymer. Among these resins, the resin particles preferably include an acrylic resin and a styrene-acrylic copolymer. Acrylic resins and styrene-acrylic copolymers have many advantages such as light weight and high strength, high transparency, low cost, and easy to obtain materials with uniform particle diameters.

  The resin used as the resin particle raw material may be the same type of resin as the binder resin contained in the toner base particles, or a different type of resin. Preferably, different types of resins are used. When a different kind of resin is used as the resin particle raw material, the softening temperature of the resin used as the resin particle raw material is preferably higher than the softening temperature of the binder resin contained in the toner base particles. As a result, the toner manufactured by the manufacturing method of the present embodiment can prevent the toners from fusing together during storage, and can improve storage stability. The softening temperature of the resin used as the resin particle raw material is preferably 80 ° C. or higher and 140 ° C. or lower, although it depends on the type of image forming apparatus in which the toner is used. By using a resin having such a temperature range, a toner having both storage stability and fixing ability can be obtained.

  The resin particles need to have a volume average particle size sufficiently smaller than the volume average particle size of the toner base particles, and are preferably 0.05 μm or more and 1 μm or less. The volume average particle diameter of the resin particles is more preferably 0.1 μm or more and 0.5 μm or less. Since the resin particles have a volume average particle diameter of 0.05 μm or more and 1 μm or less, irregularities (protrusions) of an appropriate size can be formed on the surface of the resin-coated toner, so the BET specific surface area of the resin-coated toner is defined as above. The spacer particles can be stably fixed in a semi-embedded state in the coating step. Moreover, it becomes easy to be caught by the cleaning blade at the time of cleaning, and the cleaning property is improved.

(3) Resin-coated toner preparation process As shown in FIG. 1, the resin-coated toner preparation process in step S3 includes a first temperature adjustment process S3a, a resin particle adhesion process S3b, a first spraying process S3c, and a film forming process. S3d and 1st collection process S3e are included.

  The resin particle adhesion step S3b corresponds to the first mixing step, and is a step of obtaining resin particle-attached toner by adhering resin particles to the surface of the toner mother particles by mixing the toner mother particles and the resin particles. The first spraying step S3c and the film-forming step S3d correspond to a film-forming step, and a resin-coated toner is obtained by fusing resin particles adhering to the resin particle-adhering toner using a rotary stirring device described later. is there. These steps will be described in more detail later. First, the rotary stirring device will be described.

(Rotary stirring device)
FIG. 2 is a front view showing the configuration of the rotary stirring device 201 used in the toner manufacturing method according to the present embodiment. FIG. 3 is a schematic cross-sectional view of the rotary agitator 201 shown in FIG. 2 as viewed from the cutting plane line A200-A200. In the resin-coated toner preparation process in step S3, for example, the rotary agitator 201 shown in FIG. 2 is used, and the resin particles prepared in the resin particle preparation process in step S2 are added to the toner mother particles prepared in the toner mother particle preparation process in step S1. Then, a coating layer is formed on the surface of the toner base particles by a synergistic effect of circulation in the apparatus and impact force by stirring. Moreover, the rotary stirring apparatus 201 shown in FIGS. 2 and 3 can also be used in the spacer particle semi-embedding process in step S4 described later. The rotary stirring device 201 includes a powder channel 202, a spraying means 203, a rotary stirring means 204, a temperature adjustment jacket (not shown), a powder charging unit 206, and a powder recovery unit 207. The rotary stirring means 204 and the powder flow path 202 constitute a circulation means.

(Powder channel)
The powder flow path 202 includes a rotary stirring chamber 208 and a circulation pipe 209. The rotary stirring chamber 208 is a cylindrical container-like member having an internal space. Openings 210 and 211 are formed in the rotary stirring chamber 208. The opening 210 is formed so as to penetrate the side wall including the surface 208a of the rotary stirring chamber 208 in the thickness direction at a substantially central portion of the surface 208a on one side in the axial direction of the rotary stirring chamber 208. The opening 211 is formed on a side surface 208b perpendicular to the surface 208a on one side in the axial direction of the rotary stirring chamber 208 so as to penetrate the side wall including the side surface 208b of the rotary stirring chamber 208 in the thickness direction.

  The circulation pipe 209 has one end connected to the opening 210 and the other end connected to the opening 211. As a result, the internal space of the rotary stirring chamber 208 and the internal space of the circulation pipe 209 are communicated to form the powder flow path 202. Through this powder flow path 202, toner mother particles, resin particles, and the like flow. The powder flow path 202 is provided so that the powder flow direction, which is the direction in which the toner base particles and the resin particles flow, is a constant direction.

(Rotating stirring means)
The rotating stirring means 204 includes a rotating shaft member 218, a disk-shaped rotating disk 219, and a plurality of stirring blades 220. The rotary shaft member 218 has an axis line that coincides with the axis line of the rotary stirring chamber 208 and is formed on the surface 208c on the other side in the axial direction of the rotary stirring chamber 208 so as to penetrate the side wall including the surface 208c in the thickness direction. It is a cylindrical rod-shaped member that is provided so as to be inserted through the through-hole 221 and is rotated around the axis by a motor (not shown). The rotating disk 219 is a disk-shaped member that is supported by the rotating shaft member 218 so that its axis coincides with the axis of the rotating shaft member 218 and rotates with the rotation of the rotating shaft member 218. The plurality of stirring blades 220 are supported by the peripheral portion of the turntable 219 and rotate as the turntable 219 rotates.

  The rotating shaft member 218 can rotate at a peripheral speed at the outermost periphery of 50 m / sec or more. The outermost periphery is a portion of the rotary stirring means 204 having the longest distance from the rotary shaft member 218 in the direction perpendicular to the rotary shaft member 218.

(Spraying means)
The spray means 203 is provided in the circulation pipe 209 of the powder flow path 202 on the side closest to the opening 211 in the powder flow direction. The spraying means 203 sprays a plasticizing liquid that plasticizes the toner base particles and the resin particles toward the inside of the circulation pipe. The spray means 203 mixes a liquid storage section (not shown) that stores the plasticized liquid, a carrier gas supply section (not shown) that supplies the carrier gas, the plasticizing liquid and the carrier gas, and the resulting mixture is mixed with the powder flow path. And a two-fluid nozzle 203a that sprays toward the powder existing in 202 and sprays the plasticized liquid droplets onto the powder such as toner base particles and resin particles. The two-fluid nozzle 203 a is provided by being inserted through an opening formed in the outer wall of the powder flow path 202. In this embodiment, compressed air is used as the carrier gas.

  In this embodiment, it is preferable that the spray means 203 includes a liquid feed pump. When the plasticizing liquid is sent to the two-fluid nozzle 203a at a constant flow rate by the liquid feed pump and sprayed into the powder flow path 202 by the two-fluid nozzle 203a, the plasticizing liquid is gasified, and the toner base particles and the resin particle surfaces Gasified plasticized liquid spreads. As a result, the toner base particles and the resin particles are plasticized. Since the plasticizing liquid having a constant flow rate is sprayed toward the inside of the circulation pipe 209 by the liquid feed pump, the plasticizing liquid can be gasified so as to have a constant concentration in the powder flow path. The plasticizing liquid concentration in the flow path is stable, and it is possible to prevent condensation due to a sudden increase in liquid concentration, aggregation of particles such as resin particle-attached toner, and adhesion of these particles into the powder flow path. .

  The plasticized liquid sprayed from the spraying means 203 is gasified in the powder channel 202, but the gasified plasticized liquid is such that the gas concentration in the powder channel 202 is maintained within a certain range. Then, the powder is discharged out of the powder passage 202 through the through hole 221. A concentration sensor 222 that detects the concentration of the gasified liquid is disposed in the gas discharge portion 223 that serves as a passage for the gasified plasticized liquid discharged outside the powder flow path 202. The concentration of the gasified plasticized liquid measured by the concentration sensor 222 in the gas discharge unit 223 is 3% or less in consideration of the drying speed of the plasticized liquid, the anti-aggregation property of the toner base particles, and the productivity. It is preferable to adjust to the extent. As a result, the drying speed of the plasticized liquid can be sufficiently increased, so that the resin-coated toner in which the undried plasticized liquid remains adheres to the other resin-coated toner in the resin-coated toner preparation step S3. This can prevent the aggregation of the resin-coated toner. In the spacer particle semi-embedding step S4, toner aggregation can be prevented.

  The spray rate of the plasticizing liquid measured by the concentration sensor 222 is more preferably 0.1% or more and 3.0% or less. When the spraying speed is within such a range, aggregation of the resin-coated toner and the toner can be prevented without reducing productivity.

  In the rotary stirring device 201, compressed air is used as protective air for protecting the bearing of the device, in addition to using compressed air as a carrier gas to spray the gasified plasticized liquid. Therefore, the exhaust air flow rate discharged from the powder flow path 202 is not the same as the supply flow rate of the carrier gas, but is the total amount of the carrier gas flow rate and the protective air flow rate. In the present embodiment, it is preferable that the exhaust air flow rate discharged from the powder channel 202 is adjusted to be 10 to 70 L / min. Note that the flow rate of exhaust air discharged from the powder flow path 202 varies depending on the amount of carrier gas supplied into the powder flow path 202. If the discharge air flow rate is less than 10 L / min, the concentration of the gasified plasticizing liquid in the powder flow path 202 becomes too high, and the plasticity of the toner base particles and the resin particles becomes too strong. Adhesion and aggregation of resin particles occur, and the yield of the resin-coated toner decreases. On the other hand, when the exhaust air flow rate exceeds 70 L / min, the manufactured toner is mixed with the discharged carrier gas and discharged out of the powder flow path 202, and the yield of the resin-coated toner is lowered.

(Plasticized liquid)
The plasticizing liquid that has the effect of plasticizing the toner base particles and the resin particles without being dissolved is not particularly limited. However, since the liquid needs to be removed from the toner base particles and the resin particles after spraying, the liquid must be easily evaporated. Is preferred. In order to make the liquid easy to evaporate, the plasticizing liquid preferably contains an alcohol, particularly a lower alcohol, as an organic solvent which has a low boiling point and is easily vaporized and in most cases gasifies in a sufficiently fast time. Examples of the lower alcohol include methanol, ethanol, propanol, and butanol. Further, among the lower alcohols, it is more preferable to include an alcohol having 3 or less carbon atoms in the molecule. Since such alcohol has a low viscosity and the spray droplet diameter of the plasticizing liquid sprayed from the spraying means does not become coarse, it is possible to spray the plasticizing liquid with a uniform spray droplet diameter. . At the time of collision between the powder and the droplet, it is possible to further promote the miniaturization of the droplet. As a result, in the resin coating toner preparation step S3, the wettability of the resin particles to the surface of the toner base particles can be improved, and the toner base particles and the surface of the resin particles are uniformly wetted and blended with each other. A resin-coated toner having a coating layer with excellent uniformity can be obtained by softening the resin particles. Furthermore, since the lower alcohol has a high vapor pressure, the drying time when removing the plasticizing liquid can be shortened, and aggregation of the toner base particles can be suppressed. The viscosity of the plasticizing liquid is preferably 5 cP or less. The viscosity of the plasticizing liquid is measured at 25 ° C., and can be measured, for example, with a cone-plate rotary viscometer.

  Moreover, it is preferable that the boiling point of alcohol is 20 degreeC or more higher than the glass transition temperature of a resin particle, and 20 degrees C or less higher than the glass transition temperature of a resin particle. Such alcohol has low solubility of the resin contained in the toner, and volatilizes quickly near the glass transition temperature of the resin particles. Therefore, it is possible to effectively suppress the temperature rise of the resin particle-adhered toner more than necessary. The BET specific surface area of the toner can be in the desired range defined above.

  Further, in the spacer particle semi-embedding step S4, which will be described later, the effect of semi-embedding the spacer particles with respect to the resin-coated toner is enhanced, and problems caused by the detachment of the spacer particles can be reduced. Accordingly, it is possible to obtain a resin-coated toner and toner in which the resin particles and the spacer particles are uniformly coated.

(Temperature adjustment means)
A temperature adjusting jacket (not shown), which is a temperature adjusting means, is provided in at least a part of the outside of the powder flow path 202, and the inside of the powder flow path 202 and the rotary stirring are passed through a cooling medium or a heating medium into the space inside the jacket. The temperature of the means 204 is adjusted to a predetermined temperature. In the present embodiment, the temperature adjustment jacket is preferably provided on the entire outside of the powder flow path 202. Thereby, the adhesion of the powder to the inner wall of the powder flow path 202 due to an excessive temperature rise can be suppressed. Therefore, it is possible to suppress the inside of the powder flow path 202 from being narrowed due to the adhesion of the powder. Therefore, in the resin coating toner production step S3, the resin particles are uniformly coated on the surface of the toner base particles. The coated toner can be produced with high yield. Further, in the spacer particle semi-embedding step S4, the spacer particles adhere to the resin-coated toner in a semi-buried state, the spacer effect is excellent, the spacer particles are difficult to be buried in the resin layer on the surface of the resin-coated carrier, A toner that hardly causes toner scattering can be manufactured. Further, by adjusting the temperature of the powder flow path 202 and the rotary stirring means 204 to a predetermined temperature, the resin particles adhere to the toner base particles and form a film, and the spacer particles are semi-embedded in the resin-coated toner. Since the process proceeds smoothly and the adhesion force to the inner wall of the powder channel 202 is reduced, the adhesion of the powder to the inner wall of the powder channel can be suppressed, and the inside of the powder channel 202 is prevented from becoming narrow. be able to.

(Powder input part and powder recovery part)
A powder input unit 206 and a powder recovery unit 207 are connected to the circulation pipe 209 of the powder channel 202. FIG. 4 is a front view schematically showing the configuration around the powder input unit 206 and the powder recovery unit 207. The powder input unit 206 includes a hopper (not shown) that supplies the processed powder, a supply pipe 212 that communicates the hopper and the powder flow path 202, and an electromagnetic valve 213 provided in the supply pipe 212. The treated powder supplied from the hopper is supplied to the powder flow path 202 through the supply pipe 212 in a state where the flow path in the supply pipe 212 is opened by the electromagnetic valve 213. The treated powder supplied to the powder flow path 202 flows in a constant powder flow direction by stirring by the rotary stirring means 204. Further, in a state where the flow path in the supply pipe 212 is closed by the electromagnetic valve 213, the processing powder is not supplied to the powder flow path 202.

  The powder recovery unit 207 includes a recovery tank 215, a recovery pipe 216 that connects the recovery tank 215 and the powder flow path 202, and an electromagnetic valve 217 provided in the recovery pipe 216. In a state where the flow path in the collection pipe 216 is opened by the electromagnetic valve 217, the treated powder flowing through the powder flow path 202 is collected in the collection tank 215 through the collection pipe 216. In addition, in the state where the flow path in the collection pipe 216 is closed by the electromagnetic valve 217, the processed powder flowing through the powder flow path 202 is not collected.

  Hereinafter, the resin film toner preparation step S3 using such a rotary stirring device 201 will be described.

(3) -1, first temperature adjustment step In the first temperature adjustment step of step S3a, while rotating the rotary stirring means 204, the temperature of the powder flow path 202 and the rotary stirring means 204 are arranged outside these. The temperature is adjusted to a predetermined temperature through the medium through the temperature adjusting jacket. As a result, the temperature in the powder flow path 202 can be controlled to be equal to or lower than the temperature at which the toner base particles and the resin particles introduced in the resin particle adhesion step S3b described later are not softened and deformed.

(3) -2, resin particle adhesion step S3b
In the resin particle adhering step in step S3b, the toner base particles and the resin particles are supplied from the powder input unit 206 to the powder flow path 202 while the rotating shaft member 218 of the rotating stirring unit 204 is rotating. The toner mother particles and the resin particles supplied to the powder flow path 202 are stirred by the rotary stirring means 204 and flow in the direction of the arrow 214 through the circulation pipe 209 of the powder flow path 202. As a result, the resin particles adhere to the surface of the toner base particles, and a resin particle-attached toner is obtained. In addition, since it is not necessary to spray plasticizing liquid in resin particle adhesion process S3b, a Henschel mixer etc. can be used instead of the rotary stirring apparatus 204 provided with the spraying means 203, for example.

(3) -3, first spraying step S3c
In the first spraying step of step S3c, the plasticizing liquid is sprayed by the carrier gas from the spraying means 203 onto the resin particle-attached toner that is in a fluid state in the powder flow path 202.

  In the present embodiment, it is preferable to start spraying the plasticizing liquid from the spray unit 203 after the flow rate of the resin particle-attached toner in the powder channel 202 is stabilized. Accordingly, since the liquid can be uniformly sprayed onto the resin particle-attached toner, the yield of the resin-coated toner in which the coating layer is uniformly coated can be improved.

  The angle θ formed between the liquid spray direction which is the direction of the axis of the two-fluid nozzle 203a and the powder flow direction is preferably 0 ° or more and 45 ° or less. When θ is in such a range, the plasticized liquid droplets are prevented from recoiling on the inner wall of the powder flow path 202, and the yield of the treated powder can be further improved. When the angle θ formed between the liquid spraying direction from the spraying means 203 and the powder flow direction exceeds 45 °, the plasticized liquid droplets are likely to recoil on the inner wall of the powder flow path 202, and the plasticized liquid is It becomes easy to stay and the treated powder is agglomerated and the yield is deteriorated.

  The spreading angle φ of the plasticized liquid sprayed by the two-fluid nozzle 203a is preferably 20 ° or more and 90 ° or less. If the spread angle φ is out of this range, it may be difficult to uniformly spray the plasticizing liquid on the treated powder.

(3) -4, film forming process In the film forming process of step S3d, the resin particles are softened continuously by the synergistic effect of the circulation by the rotary stirring device 201 and the impact force by the stirring, and further by the thermal energy by the stirring. The stirring of the rotary stirring means 204 is continued at a predetermined temperature until the coating film is formed on the surface of the resin particle-adhered toner, and the resin particle-adhered toner is caused to flow.

(3) -5, First Recovery Step In the first recovery step of step S3e, the spraying of the plasticizing liquid from the spraying means 203 is terminated, the rotation of the rotary stirring means 204 is stopped, and a coating layer is formed on the surface. The resin-coated toner thus discharged is discharged from the powder collecting unit 207 to the outside of the apparatus, and the resin-coated toner is collected.

(4) Spacer particle semi-embedding process The spacer particle semi-buried process of step S4 includes a second temperature adjusting process, a spacer particle attaching process, a second spraying process, an immobilizing process, and a second collecting process. The second temperature adjustment step corresponds to the second mixing step, and the resin-coated toner and the spacer particles are mixed to adhere the spacer particles to the surface of the resin-coated toner, thereby producing a spacer particle-attached toner. The second spraying step and the fixing step correspond to the spacer particle fixing step. For example, the rotating agitator 201 is used to fix the spacer particles to the resin-coated toner in a semi-embedded state to produce a toner.

(4) -1, second temperature adjustment step S4a
In the second temperature adjustment step of step S4a, while rotating the rotary stirring means 204, the temperature in the powder flow path 202 and the rotary stirring means 204 is set to a predetermined temperature through a medium through a temperature adjustment jacket disposed outside them. Adjust to. Thereby, the temperature in the powder flow path 202 can be controlled to be equal to or lower than the temperature at which the resin-coated toner and spacer particles introduced in the spacer particle adhesion step S4b described later are not softened and deformed.

(4) -2, spacer particle adhesion step S4b
In the spacer particle adhesion step of step S4b, the resin coating toner and the spacer particles are supplied to the powder flow path 202 from the powder input unit 206 while the rotary shaft member 218 of the rotary stirring means 204 is rotating. The resin-coated toner and spacer particles supplied to the powder flow path 202 are stirred by the rotating stirring means 204 and flow in the direction of the arrow 214 through the circulation pipe 209 of the powder flow path 202. As a result, the spacer particles adhere to the surface of the resin-coated toner, and a spacer particle-attached toner is obtained. In addition, since it is not necessary to spray plasticizing liquid in spacer particle | grain adhesion process S4b, instead of the rotary stirring apparatus 204 provided with the spraying means 203, a Henschel mixer etc. can be used, for example.

  As the spacer particles, silica and titanium oxide having an average primary particle diameter of 40 nm to 300 nm can be used, and the surface of these inorganic particles is surface-treated with a silane coupling agent, a titanium coupling agent, and silicone oil. Inorganic particles imparted with hydrophobicity can be used. In particular, silica particles having hexamethyldisilazane (hereinafter sometimes referred to as HMDS) as a silane coupling agent and having a trimethylsilyl group introduced on the surface are excellent in hydrophobicity and insulating properties. The fixed toner stabilizes the charge amount of the toner even in a high-humidity environment, and an excellent charging improvement effect can be obtained.

  The spacer particles having an average primary particle size of 40 nm or more and 300 nm or less have the effect of weakening the toner adhesion (van der Waals force) due to the spacer effect and improving the transfer efficiency when transferring from the photosensitive drum to the transfer medium.

  The amount of spacer particles added is preferably 0.3% by weight or more and 2% by weight or less. If it is less than 0.3% by weight, the adhesion effect (van der Waals force) of the toner is weakened by the spacer effect, and it is difficult to obtain the effect of improving the transfer efficiency. Conversely, if it exceeds 2% by weight, the toner fixing property is lowered.

  The toner surface coverage by the spacer particles is preferably 5% or more and 30% or less. When the toner surface coverage is less than 5%, it is difficult to obtain the effect of improving the fluidity by the spacer particles, and the effect of improving the transfer efficiency by the spacer effect is not sufficiently exhibited. On the other hand, if it exceeds 30%, the fixing property is lowered. Furthermore, since the external additive described later can be attached in a state where it can flow without being embedded in the surface of the toner particles, the fluidity of newly replenished toner can be improved, and good triboelectric chargeability can be obtained. can get.

The toner surface coverage Cg (%) in the present embodiment is calculated using the following formula (2) derived from the following formula (1).
Toner surface coverage Cg = (Sg ÷ St) × 100 (1)
Sg: Projected area of all spacer particles (m ² )
St: Total surface area of resin-coated toner (m ² )
That is,
Toner surface coverage Cg = 1.5 × Wg ÷ (Bt × Dg × Rg) (2)
Wg: addition amount of spacer particles (parts by weight: addition amount per 100 parts by weight of resin coating toner)
Bt: BET specific surface area per gram of resin-coated toner (m ² / g)
Dg: average primary particle size (m) of spacer particles
Rg: Specific gravity of spacer particles (g / m ³ )

The above formula (2) is derived from the above formula (1) as follows.
The projected area (m ² ) of one spacer particle is represented by the following formula (3).
π × (Dg / 2) ² (3)

The volume (m ³ ) of one spacer particle is represented by the following formula (4).
4/3 × π × (Dg / 2) ³ (4)

The weight (g) of one spacer particle is obtained by multiplying the volume of one spacer particle by the specific gravity (Rg) of the spacer particle. That is, it is represented by the following formula (5) obtained by multiplying the above formula (4) by the specific gravity (Rg) of the spacer particles.
4/3 × π × (Dg / 2) ³ × Rg (5)

The projected area (m ³ ) of spacer particles per 1 g of spacer particles can be obtained by dividing the projected area of one spacer particle by the weight of one spacer particle. That is, it is represented by the following formula (6) obtained by dividing the above formula (3) by the above formula (5).
1.5 ÷ (Dg × Rg) (6)

When the weight of the resin-coated toner is 100 parts by weight, the total projected area Sg (m ² ) of the spacer particles is obtained by multiplying the projected area of the spacer particles per 1 g of the spacer particles by the added amount of the spacer particles. That is, it is represented by the following formula (7) obtained by multiplying the above formula (6) by the added amount Wg of spacer particles.
Total projected area Sg of spacer particles = 1.5 × Wg ÷ (Dg × Rg) (7)

The total surface area St (m2) of the resin-coated toner when the weight of the resin-coated toner is 100 parts by weight is represented by the following formula (8).
Total surface area of resin-coated toner St = Bt × 100 (8)

By substituting the total projected area Sg of the spacer particles and the total surface area St of the resin-coated toner obtained as described above into the above formula (1), the toner surface coverage Cg represented by the formula (2) can be derived. it can.
Toner surface coverage Cg = [{1.5 × Wg ÷ (Dg × Rg)} ÷ (Bt × 100)]
× 100
= 1.5 × Wg ÷ (Bt × Dg × Rg)

In the present embodiment, the spacer particles and the external additive described later are silica having a volume resistivity in the range of 1 × 10 ¹² Ω · cm or more and 5 × 10 ¹⁵ Ω · cm or less as measured by a compression method. Particles are preferred. When the volume resistivity is less than 1 × 10 ¹² Ω · cm, the charge amount tends to decrease when the toner is left, and image fogging easily occurs after the toner is left, and the volume resistivity is 5 × 10 ¹⁵ Ω · cm. Exceeding silica particles are difficult to produce and costly.

The volume resistivity of silica particles using the compression method was measured by the following procedure. First, silica particles after being allowed to stand for 24 hours in an environment of an air temperature of 20 ° C. and a humidity of 65% are sandwiched between two copper plate electrodes, the pressing pressure is 10 kg / cm ² , and the distance between the copper plate electrodes is 8 to A compact having a size of 10 mm was produced. Next, a voltage of 500 V / cm was applied as the electric field strength, the resistance 15 seconds after the voltage application was measured, and the value was taken as the volume resistivity of the silica particles.

(4) -3, Second Spraying Step In the second spraying step of step S4c, the plasticizing liquid is sprayed from the spraying means 203 to the spacer particle-attached toner that is in a fluid state in the powder flow path 202 by the carrier gas. The plasticizing liquid is fed to the spraying means 203 at a constant flow rate by a liquid feed pump, the plasticizing liquid sprayed by the spraying means 203 is gasified, and the gasified liquid spreads on the spacer particle-attached toner. As a result, the toner adhering to the spacer particles is plasticized.

  In the present embodiment, it is preferable that the spraying of the plasticizing liquid from the spraying unit 203 is started after the flow rate of the spacer particle-attached toner is stabilized in the powder channel 202. Accordingly, the plasticizing liquid can be uniformly sprayed on the spacer particle-attached toner, so that the spacer particles are fixed uniformly.

(4) -4, Immobilization Step In the immobilization step of step S4d, the coating layer on the surface of the spacer particle-attached toner is formed by the synergistic effect of the circulation by the rotary agitator 201 and the impact force by the agitation and the thermal energy by the agitation. The spacer particles and the external additive are softened so that the spacer particles are semi-buried in the coating layer, and the stirring of the rotary stirring means 204 is continued at a predetermined temperature until the spacer particles are fixed. Let it flow.

  The degree of burying of the spacer particles can also be adjusted, for example, by changing the peripheral speed of the stirring blade of the rotary stirring device 201 and the internal temperature of the mixing device. The higher the peripheral speed of the stirring blade and the higher the internal temperature of the powder flow path 202, the more easily the spacer particles are buried. However, the peripheral speed of the stirring blade is too high or the internal temperature of the powder flow path 202 is high. After that, the toner aggregates. Therefore, the peripheral speed of the outermost periphery of the rotary stirring means 204 is set within a range of 30 m / sec or more and 60 m / sec or less, and the internal temperature of the powder channel 202 is changed from room temperature to the toner. It is preferably set within the temperature range of the glass transition temperature. When the peripheral speed at the outermost periphery of the rotating stirring means 204 during rotation is not less than 30 m / sec and not more than 60 m / sec, the impact force necessary for fixing the spacer particles is generated after the spacer particle-attached toner surface is softened. Can be made. Therefore, sufficient external addition strength of the spacer particles can be obtained, and various problems due to desorption of the spacer particles can be reduced.

  When the peripheral speed at the outermost periphery is less than 30 m / sec, the energy for semi-embedding the spacer particles in the coating layer on the surface of the resin-coated toner is insufficient, and a problem due to spacer particle detachment occurs. The outermost periphery of the rotary stirring means 204 is a portion 204a of the rotary stirring means 204 having the longest distance from the axis of the rotary shaft member 218 in the direction perpendicular to the direction in which the rotary shaft member 218 of the rotary stirring means 204 extends.

(4) -5, Second Recovery Step In the second recovery step of step S4e, the spraying of the plasticizing liquid from the spraying means 203 is terminated, the rotation of the rotary stirring means 204 is stopped, and the spacer particles are made of resin-coated toner. The toner fixed in a semi-embedded state with respect to the resin layer is discharged from the powder collecting unit 207 to the outside of the rotary stirring device 201 and collected.

  The toner is manufactured as described above. In the resin film toner production step S3, the peripheral speed of the outermost periphery of the rotary stirring means 204 is preferably set to 30 m / sec or more, and set to 50 m / sec or more. More preferably. When the peripheral speed at the outermost periphery of the rotating stirring means 204 at the time of rotation is 30 m / sec or more, the toner mother particles can be isolatedly flowed. If the peripheral speed at the outermost periphery is less than 30 m / sec, the toner base particles and the resin particles cannot be isolatedly flowed, so that the toner base particles cannot be uniformly coated with the resin film.

  In the resin coating toner preparation step S3 and the spacer particle semi-embedding step S4, a temperature adjusting jacket is provided in at least a part of the powder channel 202, and the powder channel is passed through a cooling medium or a heating medium in the space inside the jacket. The temperature in 202 is adjusted to a predetermined temperature. As a result, in the temperature adjustment steps S3a and S4a, the toner mother particles and the resin particles or the resin-coated toner charged in the resin particle adhesion step S3b and the spacer particle adhesion step S4b are set to the temperatures outside the powder flow path and the rotary stirring means. Can be controlled to a temperature that does not cause softening deformation. Further, in the spraying steps S3c, S4c, the film-forming step S3d, and the fixing step S4d, the temperature applied to the toner base particles, resin particles, resin-coated toner, spacer particles, and plasticizing liquid is less varied, and the treated powder A stable fluid state can be maintained.

  In addition, toner base particles and resin particles made of synthetic resin or the like usually collide with the inner wall of the powder flow path 202 many times, and at the time of the collision, part of the collision energy is converted into thermal energy, and the toner base Accumulated in particles and resin particles. As the number of collisions increases, the thermal energy accumulated in these particles increases, and the toner base particles and resin particles eventually soften and adhere to the inner wall of the powder flow path 202. By adjusting the temperature through the cooling medium or the heating medium in the space, it is possible to suppress the adhesion of the toner base particles and the resin particles to the inner wall of the powder flow path due to excessive temperature rise, and the liquid sprayed from the spraying means 203 Can be prevented from adhering to the powder flow path 202 due to the accumulation of toner particles in the powder flow path 202 and clogging in the powder flow path 202 due to this. Therefore, the resin mother toner particles are uniformly coated with the resin particles, and the resin-coated toner excellent in the cleaning property, which is coated with the coating layer, can be produced with high yield. Furthermore, the spacer particles are strongly fixed to the coating layer of the resin-coated toner, so that a toner with little spacer particle detachment can be produced.

  Inside the circulation pipe 209 downstream of the spraying means 203, the sprayed plasticizing liquid remains without being dried, and if the temperature is not appropriate, the drying speed becomes slow and the plasticizing liquid tends to stay. When the toner particles come into contact with the toner particles, the toner particles easily adhere to the inner wall of the powder flow path 202. This can be a source of toner particle aggregation. On the inner wall in the vicinity of the opening 210, toner particles flowing through the circulation pipe 209 and flowing into the rotary stirring chamber 208 from the opening 210 and toner particles flowing in the rotary stirring chamber 208 by stirring by the rotary stirring means 204 are mixed. Easy to collide. As a result, the collided toner particles are likely to adhere to the vicinity of the opening 210. Therefore, by providing a temperature adjustment jacket at a portion where such toner particles are likely to adhere, it is possible to more reliably prevent the toner particles from adhering to the inner wall of the powder flow path 202.

  The temperature in the powder flow path 202 is set to be equal to or lower than the glass transition temperature of the toner base particles. The temperature in the powder channel 202 is more preferably 30 ° C. or higher and the glass transition temperature of the toner base particles or lower. The temperature in the powder flow path 202 becomes almost uniform in any part of the powder flow path 202 due to the flow of the toner particles. When the temperature in the powder flow path 202 exceeds the glass transition temperature of the toner base particles, the toner base particles are excessively softened in the powder flow path 202 and the toner particles may be aggregated. On the other hand, if the temperature in the powder flow path 202 is lower than 30 ° C., the drying rate of the plasticizing liquid may be slowed and productivity may be reduced. Therefore, in order to prevent aggregation of the toner particles, the inner diameter is larger than the outer diameter of the powder flow path 202 in order to keep the temperature of the powder flow path 202 and the rotary stirring means 204 below the glass transition temperature of the toner base particles. It is necessary to dispose a temperature adjusting jacket on at least a part of the outside of the powder flow path 202 and the rotary stirring means 204 and to provide a device having a function of adjusting the temperature through a cooling medium or a heating medium in the space. is there.

  As described above, the rotating agitation means 204 includes the rotating disk 219 that rotates as the rotating shaft member 218 rotates, and the treated powder preferably collides with the rotating disk 219 perpendicular to the rotating disk 219. More preferably, the rotary shaft member 218 collides with the rotary disk 219 perpendicularly. As a result, the toner base particles and the resin particles can be sufficiently agitated rather than the toner base particles and the resin particles colliding with the rotating disk 219 in parallel, so that the toner base particles are more uniformly coated with the resin particles. The yield of the resin-coated toner in which the coating layer is uniformly coated can be further improved. Further, since the resin-coated toner and the external additive can give a sufficient impact force to the resin-coated toner and the spacer particles rather than colliding with the rotating disk 219 in parallel, the spacer is applied to the coating layer on the surface of the resin-coated toner. Particles can be immobilized in a semi-buried state.

  The rotary stirrer 201 used in the resin coating toner preparation step S3 and the spacer particle semi-embedding step S4 is not limited to the above-described configuration, and various changes can be made. For example, the temperature adjusting jacket may be provided on the entire outer surface of the circulation pipe 209 and the rotary stirring chamber 208, or may be provided on a part of the outer side of the circulation pipe 209 or the rotary stirring chamber 208. If the temperature adjustment jacket is provided on the entire outer surface of the circulation pipe 209 and the rotary stirring chamber 208, it is possible to more reliably prevent the treated powder from adhering to the inner wall of the powder flow path 202.

  Further, the rotary stirring device used in the resin film toner preparation step S3 and the spacer particle semi-embedding step S4 can be obtained by combining a commercially available stirring device and spraying means. As a commercially available stirring apparatus provided with a powder flow path and rotating stirring means, for example, a hybridization system (trade name, manufactured by Nara Machinery Co., Ltd.) and the like can be mentioned. By mounting a liquid spray unit in such a stirring device, this stirring device can be used as a device used in the toner production method of the present invention.

  On the surface of the toner obtained by the toner manufacturing method of the present embodiment, inorganic particles having a particle diameter smaller than that of the spacer particles may be externally added as an external additive. As the inorganic particles having a particle diameter smaller than that of the spacer particles (hereinafter also referred to as “external additive”), the same kind of inorganic particles as the spacer particles can be used. Similarly to the spacer particles, the external additive is preferably surface-treated with a silicone resin, a silane coupling agent or the like. External additives improve toner fluidity and chargeability by adding a small amount, prevent toner aggregation and blocking from occurring in the toner replenishment path, and speed up the start-up property of charging by stirring with a carrier. Have The particle diameter of the external additive is preferably about 7 to 30 nm in average primary particle diameter, and the amount of the external additive used is preferably 0.5 part by weight or more and 2 parts by weight or less with respect to 100 parts by weight of the toner.

  If the added amount of the external additive is less than 0.5 parts by weight, it is difficult to impart sufficient fluidity to the toner. Conversely, if the added amount of the external additive exceeds 2 parts by weight, the toner fixability is lowered. In the present embodiment, the particle size of the external additive is measured using a scanning electron microscope (SEM).

  Even when the additive amount of the external additive is small (less than 0.5 parts by weight), it is possible to improve the fluidity by increasing the additive amount of the spacer particles. In order to give it, it is necessary to add a large amount (more than 2 parts by weight) of spacer particles, which is not preferable.

  Examples of the external additive having such a particle size include Aerosil 50 (average primary particle size: about 30 nm), Aerosil 90 (average primary particle size: about 30 nm), Aerosil 130 (average primary particle size) manufactured by Nippon Aerosil Co., Ltd. : About 16 nm), Aerosil 200 (average primary particle size: about 12 nm), RX-200 (average primary particle size: about 12 nm), Aerosil 300 (average primary particle size: about 7 nm), Aerosil 380 (Average primary particle size: About 7 nm), Alum Oxide C (average primary particle size: about 13 nm), Titanium Oxide P-25 (average primary particle size: about 21 nm), MOX170 (average primary particle size: about 15 nm), Ishihara Sangyo TTO-51 (average primary particle size: about 20 nm), TTO-55 (average primary particle size: about 40 nm), etc. It is below.

2. Toner The toner according to the second embodiment of the present invention is manufactured by the above-described toner manufacturing method of the present invention. Therefore, in the toner of the present invention, the resin particles are uniformly formed on the surface of the toner base particles to form a coating layer, so that the toner characteristics such as the charging characteristics between the individual toner particles are uniform. In addition, since the toner of the present invention exhibits the effect of protecting the encapsulated components by the coating layer on the surface of the toner, the storage stability is prevented from deteriorating even when a low melting point material is used for the toner base particles. Can do. Further, since the toner particles of the present invention manufactured by the toner manufacturing method of the present invention are difficult to desorb spacer particles from the surface, it is possible to prevent photoconductor filming and carrier contamination by the desorbed spacer particles. Therefore, since the decrease in the toner charging ability of the carrier can be suppressed, it is possible to stably form a high-definition and good-quality image with no density unevenness over a long period of time without fogging and toner scattering. it can.

  The toner of this embodiment has a volume average particle diameter of 4 to 7 μm, and spacer particles of 40 nm or more and 300 nm or less are fixed in a semi-embedded state on the toner surface. Further, an external additive having a particle diameter smaller than that of the spacer particles is externally added as necessary.

  FIG. 5 is a conceptual cross-sectional view showing the adhesion state of the spacer particles 5 and the external additive 4 at the initial stage of the toner particles 1 contained in the toner of the present embodiment. The toner particle 1 has a coating layer 3 formed on the surface of the toner base particle 2 and adheres to the surface of the coating layer 3 in a state where the external additive 4 can flow, and the spacer particles 5 are coated with the coating layer of the toner particle 1. 3 fixed to the surface in a semi-buried state.

  FIG. 6 is a conceptual cross-sectional view showing the adhesion state of the spacer particles 5 and the external additive 4 over time with the toner particles 1 of the present embodiment. In the toner particles over time, the external additive 4 is embedded in the coating layer 3, but in the toner of the present invention comprising the toner particles 1 shown in FIG. 5, the external additive 4 is embedded in the coating layer 3. The effect of lowering the adhesive force and improving the transfer efficiency due to the unevenness of the surface of the spacer particles 5 is obtained. At the same time, the spacer particles 5 are not easily detached from the surface of the coating layer 3 of the toner particles 1, so that the two-component developer comprising the toner of the present invention and the resin-coated carrier is stirred for a long time in the developing tank. Even so, the spacer particles 5 can be prevented from moving from the toner particles 1 and adhering to the resin layer formed on the surface of the carrier core material, so that the newly replenished toner can be frictionally charged over a long period of time. Thus, it is possible to prevent the occurrence of fogging and toner scattering due to toner charging failure.

  The spacer particles are buried in the toner surface, semi-buried, or completely buried in the coating layer. Using a microtome, the cured product obtained by embedding the toner in a room temperature curable epoxy resin was cut into ultra-thin sections of about 100 μm, and a transmission electron microscope (TEM, trade name: H-8100, Hitachi, Ltd.) Judgment was made by observing the cross section of the toner at 20000 times.

3. Two-Component Developer The two-component developer according to the third embodiment of the present invention includes the toner of the present invention described above. As a result, a developer having uniform toner characteristics such as charging characteristics between individual toner particles can be obtained, so that a developer capable of maintaining good developability can be obtained. In addition, even when a low melting point material is used for the toner base particles, the developer can be prevented from deteriorating the storage stability, so the deterioration of fluidity is reduced even when used in a high temperature atmosphere. Thus, a developer capable of maintaining good developability is obtained.

  Further, since the spacer particles of the toner of the present invention are not easily detached from the surface, it is possible to prevent photoconductor filming and carrier contamination due to the detached spacer particles. Therefore, since the decrease in the toner charging ability of the carrier can be suppressed, it is possible to stably form a high-definition and good-quality image with no density unevenness over a long period of time without fogging and toner scattering. it can.

  The two-component developer of this embodiment can be used as a one-component developer or a two-component developer. When used as a one-component developer, the toner is used alone without using a carrier. When used as a one-component developer, a blade and a fur brush are used, and the toner is conveyed by friction charging with a developing sleeve to adhere the toner onto the sleeve, thereby forming an image. When used as a two-component developer, the toner of the present invention is used with a carrier.

(Career)
As the carrier, a known carrier can be used. For example, a resin-coated carrier or a resin in which iron or copper, zinc, nickel, cobalt, manganese, chromium or the like alone or a composite ferrite and carrier core particles are coated with a coating material. And a resin-dispersed carrier in which magnetic particles are dispersed. Known coating materials can be used, such as polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicon resin, polyester resin, metal compound of ditertiary butylsalicylic acid, styrene resin, acrylic resin , Polyamide, polyvinyl butyral, nigrosine, amino acrylate resin, basic dye, basic dye lake, silica fine powder, alumina fine powder, and the like. Moreover, although it does not restrict | limit especially as resin used for a resin dispersion type carrier, For example, a styrene acrylic resin, a polyester resin, a fluorine resin, a phenol resin, etc. are mentioned. Either of them is preferably selected according to the toner component, and one kind can be used alone or two or more kinds can be used in combination.

The shape of the carrier is preferably a spherical shape or a flat shape. The particle size of the carrier is not particularly limited, but is preferably 10 to 100 μm, more preferably 20 to 50 μm, considering high image quality. Furthermore, the resistivity of the carrier is preferably 10 ⁸ Ω · cm or more, more preferably 10 ¹² Ω · cm or more.

The volume resistivity of the carrier is determined by placing the carrier in a container having a cross-sectional area of 0.50 cm ² and tapping, then applying a load of 1 kg / cm ² to the particles packed in the container, This is a value obtained by reading a current value when a voltage generating an electric field of 1000 V / cm is applied. When the resistivity is low, when a bias voltage is applied to the developing sleeve, charges are injected into the carrier, and carrier particles easily adhere to the photoreceptor. Further, breakdown of the bias voltage is likely to occur.

  The magnetization strength (maximum magnetization) of the carrier is preferably 10 to 60 emu / g, more preferably 15 to 40 emu / g. The magnetization strength depends on the magnetic flux density of the developing roller, but under the general magnetic flux density conditions of the developing roller, if it is less than 10 emu / g, the magnetic binding force does not work and causes carrier scattering. There is a fear. On the other hand, if the magnetization strength exceeds 60 emu / g, the rising of the carrier becomes too high, so that it is difficult to maintain the non-contact state with the image carrier in the non-contact development. Further, in the contact development, there is a risk that a sweep is likely to appear in the toner image.

The use ratio of the toner and the carrier in the two-component developer is not particularly limited, and can be appropriately selected according to the kind of the toner and the carrier. However, if the resin-coated carrier (density 4 to 8 g / cm ³ ) is taken as an example, the development is performed. The toner may be used so that the toner is contained in 2 to 30% by weight, preferably 2 to 20% by weight of the total amount of the developer. In the two-component developer, the carrier coverage with the toner is preferably 40 to 80%.

4. Image Forming Apparatus FIG. 7 is a cross-sectional view schematically showing a configuration of an image forming apparatus 100 according to the fourth embodiment of the present invention. The image forming apparatus 100 is a multifunction machine having both a copying function, a printer function, and a facsimile function, and forms a full-color or monochrome image on a recording medium in accordance with transmitted image information. That is, the image forming apparatus 100 has three types of printing modes, ie, a copier mode (copying mode), a printer mode, and a FAX mode. Operation input from an operation unit (not shown), personal computer, portable terminal device, information A print mode is selected by a control unit (not shown) in response to reception of a print job from an external device using a recording storage medium or a memory device.

  The image forming apparatus 100 includes a photosensitive drum 11 that is an image carrier, an image forming unit 102, a transfer unit 103, a fixing unit 104, a recording medium supply unit 105, and a discharge unit 106. Each member constituting the image forming unit 102 and some members included in the transfer unit 103 are black (b), cyan (c), magenta (m), and yellow (y) included in the color image information. In order to correspond to image information, four each are provided. Here, each member provided by four according to each color is distinguished by attaching an alphabet representing each color to the end of the reference symbol, and when referring collectively, only the reference symbol is used.

  The image forming unit 102 includes a charging unit 12, an exposure unit 13, a developing device 14, and a cleaning unit 15. The charging unit 12 and the exposure unit 13 function as a latent image forming unit. The charging unit 12, the developing device 14, and the cleaning unit 15 are arranged around the photosensitive drum 11 in this order. The charging unit 12 is disposed below the developing device 14 and the cleaning unit 15 in the vertical direction.

The photosensitive drum 11 is a roller-like member that is provided so as to be rotatable about an axis by a rotation driving unit (not shown), and on which an electrostatic latent image is formed. The rotation driving means of the photosensitive drum 11 is controlled by a control means realized by a central processing unit (CPU). The photosensitive drum 11 includes a conductive substrate (not shown) and a photosensitive layer (not shown) formed on the surface of the conductive substrate. The conductive substrate can take various shapes, and examples thereof include a cylindrical shape, a columnar shape, and a thin film sheet shape. Among these, a cylindrical shape is preferable. The conductive substrate is formed of a conductive material.

  As the conductive material, those commonly used in this field can be used. For example, metals such as aluminum, copper, brass, zinc, nickel, stainless steel, chromium, molybdenum, vanadium, indium, titanium, gold, platinum, etc. A conductive layer made of one or more of aluminum, aluminum alloy, tin oxide, gold and indium oxide is formed on a film-like substrate such as two or more alloys, synthetic resin film, metal film or paper. And a resin composition containing conductive particles and / or a conductive polymer. As the film-like substrate used for the conductive film, a synthetic resin film is preferable, and a polyester film is particularly preferable. Moreover, as a formation method of the electroconductive layer in an electroconductive film, vapor deposition, application | coating, etc. are preferable.

  The photosensitive layer is formed, for example, by laminating a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material. In that case, it is preferable to provide an undercoat layer between the conductive substrate and the charge generation layer or the charge transport layer. By providing an undercoat layer, it is possible to cover the scratches and irregularities present on the surface of the conductive substrate, smooth the surface of the photosensitive layer, and prevent deterioration of the chargeability of the photosensitive layer during repeated use. And / or the advantage of improving the charging characteristics of the photosensitive layer in a low humidity environment can be obtained. Further, a laminated photoreceptor having a three-layer structure having a high durability and having a photoreceptor surface protective layer as the uppermost layer may be used.

  The charge generation layer is mainly composed of a charge generation material that generates a charge when irradiated with light, and contains a known binder resin, plasticizer, sensitizer and the like as necessary. As the charge generation material, those commonly used in this field can be used, for example, perylene pigments such as perylene imide and perylene acid anhydride, polycyclic quinone pigments such as quinacridone and anthraquinone, metal and metal-free phthalocyanines, and halogenated compounds. Phthalocyanine pigments such as metal-free phthalocyanine, squalium dye, azulenium dye, thiapyrylium dye, carbazole skeleton, styryl stilbene skeleton, triphenylamine skeleton, dibenzothiophene skeleton, oxadiazole skeleton, fluorenone skeleton, bis-stilbene skeleton, distyryl And azo pigments having an oxadiazole skeleton or a distyrylcarbazole skeleton. Among these, metal-free phthalocyanine pigments, oxotitanyl phthalocyanine pigments, bisazo pigments containing a fluorene ring and / or a fluorenone ring, bisazo pigments composed of aromatic amines, trisazo pigments, etc. have high charge generation ability and high sensitivity. Suitable for obtaining a photosensitive layer. One type of charge generating material can be used alone, or two or more types can be used in combination. Although the content of the charge generation material is not particularly limited, it is preferably 5 parts by weight or more and 500 parts by weight or less, more preferably 10 parts by weight or more and 200 parts by weight or less with respect to 100 parts by weight of the binder resin in the charge generation layer. is there. As the binder resin for the charge generation layer, those commonly used in this field can be used. For example, melamine resin, epoxy resin, silicone resin, polyurethane, acrylic resin, vinyl chloride-vinyl acetate copolymer resin, polycarbonate, phenoxy resin , Polyvinyl butyral, polyarylate, polyamide and polyester. Binder resin can be used individually by 1 type, or can use 2 or more types together as needed.

  The charge generation layer generates charge by dissolving or dispersing appropriate amounts of charge generation materials, binder resins and, if necessary, plasticizers and sensitizers in an appropriate organic solvent that can dissolve or disperse these components. It can be formed by preparing a layer coating solution, applying this charge generation layer coating solution to the surface of the conductive substrate, and drying the surface of the conductive substrate. The film thickness of the charge generation layer thus obtained is not particularly limited, but is preferably 0.05 μm or more and 5 μm or less, more preferably 0.1 μm or more and 2.5 μm or less.

  The charge transport layer laminated on the charge generation layer has a charge transport material having the ability to accept and transport the charge generated from the charge generation material and a binder resin for the charge transport layer as essential components. Contains known antioxidants, plasticizers, sensitizers, lubricants and the like. As the charge transport material, those commonly used in this field can be used, for example, poly-N-vinylcarbazole and its derivatives, poly-γ-carbazolylethyl glutamate and its derivatives, pyrene-formaldehyde condensate and its derivatives, Polyvinylpyrene, polyvinylphenanthrene, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, 9- (p-diethylaminostyryl) anthracene, 1,1-bis (4-dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline, pyrazoline Derivatives, phenylhydrazones, hydrazone derivatives, triphenylamine compounds, tetraphenyldiamine compounds, triphenylmethane compounds, stilbene compounds, 3-methyl-2-benzothiazoli Electron donating substances such as azine compounds having a ring, fluorenone derivatives, dibenzothiophene derivatives, indenothiophene derivatives, phenanthrenequinone derivatives, indenopyridine derivatives, thioxanthone derivatives, benzo [c] cinnoline derivatives, phenazine oxide derivatives, tetra And electron accepting substances such as cyanoethylene, tetracyanoquinodimethane, promanyl, chloranil, and benzoquinone. The charge transport materials can be used alone or in combination of two or more. Although the content of the charge transport material is not particularly limited, it is preferably 10 parts by weight or more and 300 parts by weight or less, more preferably 30 parts by weight or more and 150 parts by weight or less with respect to 100 parts by weight of the binder resin in the charge transport material. .

  As the binder resin for the charge transport layer, those commonly used in this field and capable of uniformly dispersing the charge transport material can be used. For example, polycarbonate, polyarylate, polyvinyl butyral, polyamide, polyester, polyketone, epoxy resin, polyurethane , Polyvinyl ketone, polystyrene, polyacrylamide, phenol resin, phenoxy resin, polysulfone resin, and copolymer resins thereof. Among these, in consideration of film formability, wear resistance of the resulting charge transport layer, electrical characteristics, etc., polycarbonate containing bisphenol Z as a monomer component (hereinafter referred to as “bisphenol Z type polycarbonate”), bisphenol Z type polycarbonate A mixture of and other polycarbonates is preferred. Binder resin can be used individually by 1 type, or can use 2 or more types together.

  The charge transport layer preferably contains an antioxidant together with the charge transport material and the binder resin for the charge transport layer. As the antioxidant, those commonly used in this field can be used, and examples thereof include vitamin E, hydroquinone, hindered amine, hindered phenol, paraphenylenediamine, arylalkane and derivatives thereof, organic sulfur compounds, and organic phosphorus compounds. It is done. One antioxidant can be used alone, or two or more antioxidants can be used in combination. The content of the antioxidant is not particularly limited, but is 0.01% by weight or more and 10% by weight or less, preferably 0.05% by weight or more and 5% by weight or less of the total amount of components constituting the charge transport layer.

  The charge transport layer is dissolved or dispersed in a suitable organic solvent capable of dissolving or dispersing these components, such as a charge transport material, a binder resin, and if necessary, an antioxidant, a plasticizer, and a sensitizer. The charge transport layer coating liquid is prepared, the charge transport layer coating liquid is applied to the surface of the charge generation layer, and the charge generation layer surface is dried. The film thickness of the charge transport layer thus obtained is not particularly limited, but is preferably 10 μm or more and 50 μm or less, more preferably 15 μm or more and 40 μm or less.

  A photosensitive layer in which a charge generation material and a charge transport material are present can be formed in one layer. In that case, the type, content, binder resin, and other additives of the charge generation material and the charge transport material may be the same as in the case of separately forming the charge generation layer and the charge transport layer.

  In this embodiment, the photosensitive drum formed by forming the organic photosensitive layer using the charge generation material and the charge transport material as described above is used. Instead, an inorganic photosensitive layer using silicon or the like is formed. A photosensitive drum can be used.

  The charging unit 12 faces the photosensitive drum 11 and is arranged so as to be separated from the surface of the photosensitive drum 11 along the longitudinal direction of the photosensitive drum 11 with a gap, and the surface of the photosensitive drum 11 has a predetermined polarity and Charge to potential. As the charging unit 12, a charging brush type charger, a charger type charger, a sawtooth type charger, an ion generator, or the like can be used. In the present embodiment, the charging unit 12 is provided so as to be separated from the surface of the photosensitive drum 11, but is not limited thereto. For example, a charging roller may be used as the charging unit 12, and the charging roller may be arranged so that the charging roller and the photosensitive drum are in pressure contact with each other, or a contact charging type charger such as a charging brush or a magnetic brush may be used. .

  The exposure unit 13 is arranged such that light of each color information emitted from the exposure unit 13 passes between the charging unit 12 and the developing device 14 and is irradiated on the surface of the photosensitive drum 11. The exposure unit 13 branches the image information into light of each color information of black, cyan, magenta, and yellow in the unit, and the surface of the photosensitive drum 11 charged to a uniform potential by the charging unit 12 is light of each color information. To form an electrostatic latent image on the surface. As the exposure unit 13, for example, a laser scanning unit including a laser irradiation unit and a plurality of reflecting mirrors can be used. In addition, a unit in which an LED array or a liquid crystal shutter and a light source are appropriately combined may be used.

  The cleaning unit 15 uses the developing device 14 to transfer the toner image formed on the surface of the photosensitive drum 11 to a recording medium, and then removes the toner remaining on the surface of the photosensitive drum 11 to remove the surface of the photosensitive drum 11. Clean. For the cleaning unit 15, for example, a plate-like member such as a cleaning blade is used. In the image forming apparatus of the present embodiment, an organic photosensitive drum is used as the photosensitive drum 11, and the surface of the organic photosensitive drum is mainly composed of a resin component, and thus is generated by corona discharge by a charging device. Deterioration of the surface of the organic photosensitive drum is likely to proceed due to the chemical action of ozone. However, the deteriorated surface portion is worn by receiving the rubbing action by the cleaning unit 15, and the gradually deteriorated surface portion is surely removed. Therefore, the problem of surface deterioration due to ozone or the like is practically solved, and the charging potential by the charging operation can be stably maintained over a long period of time. Although the cleaning unit 15 is provided in this embodiment, the present invention is not limited to this, and the cleaning unit 15 may not be provided.

  The image forming unit 102 forms an electrostatic latent image by irradiating the surface of the photosensitive drum 11 that is uniformly charged by the charging unit 12 with signal light corresponding to the image information from the exposure unit 13. Then, the toner is supplied from the developing device 14 to form a toner image. After the toner image is transferred to the intermediate transfer belt 25, the toner remaining on the surface of the photosensitive drum 11 is removed by the cleaning unit 15. This series of toner image forming operations is repeatedly executed to form an image.

  The transfer means 103 is disposed above the photosensitive drum 11 and has four intermediate portions corresponding to the intermediate transfer belt 25, the drive roller 26, the driven roller 27, and the image information of each color of black, cyan, magenta, and yellow. A transfer roller 28, a transfer belt cleaning unit 29, and a transfer roller 30 are included. The intermediate transfer belt 25 is an endless belt-like member that is stretched around a driving roller 26 and a driven roller 27 to form a loop-shaped movement path, and is driven to rotate in the direction of an arrow B. The driving roller 26 is provided so as to be rotatable around its axis by driving means (not shown), and the intermediate transfer belt 25 is driven to rotate in the direction of arrow B by the rotational driving. The driven roller 27 is provided so as to be able to be driven and rotated by the rotational drive of the driving roller 26, and applies a certain tension to the intermediate transfer belt 25 so that the intermediate transfer belt 25 does not loosen. The intermediate transfer roller 28 is provided in pressure contact with the photosensitive drum 11 via the intermediate transfer belt 25 and capable of being driven to rotate about its axis by a driving unit (not shown). The intermediate transfer roller 28 is connected to a power source (not shown) for applying a transfer bias as described above, and has a function of transferring the toner image on the surface of the photosensitive drum 11 to the intermediate transfer belt 25.

  When the intermediate transfer belt 25 passes through the photoconductive drum 11 while being in contact with the photoconductive drum 11, the toner on the surface of the photoconductive drum 11 is transferred from the intermediate transfer roller 28 disposed opposite to the photoconductive drum 11 through the intermediate transfer belt 25. A transfer bias having a polarity opposite to the charging polarity is applied, and the toner image formed on the surface of the photosensitive drum 11 is transferred to the intermediate transfer belt 25. In the case of a full-color image, each color toner image formed on each photoconductor drum 11 is sequentially transferred onto the intermediate transfer belt 25 to form a full-color toner image.

  The transfer belt cleaning unit 29 is provided so as to face the driven roller 27 through the intermediate transfer belt 25 and to contact the outer peripheral surface of the intermediate transfer belt 25. The toner adhering to the intermediate transfer belt 25 due to contact with the photosensitive drum 11 causes the recording medium to be contaminated. Therefore, the transfer belt cleaning unit 29 removes and collects the toner on the surface of the intermediate transfer belt 25.

  The transfer roller 30 is provided in pressure contact with the drive roller 26 via the intermediate transfer belt 25, and can be driven to rotate about an axis by a drive unit (not shown). The toner image that is carried and conveyed by the intermediate transfer belt 25 at the pressure contact portion between the transfer roller 30 and the drive roller 26, that is, the transfer nip portion, is transferred to a recording medium fed from a recording medium supply unit 105 described later. The The recording medium carrying the toner image is fed to the fixing unit 104.

  According to the transfer unit 103, the toner image transferred from the photosensitive drum 11 to the intermediate transfer belt 25 at the pressure contact portion between the photosensitive drum 11 and the intermediate transfer roller 28 rotates the intermediate transfer belt 25 in the arrow B direction. It is conveyed to a transfer nip portion by driving, and transferred to a recording medium there.

  The fixing unit 104 is provided downstream of the transfer unit 103 in the conveyance direction of the recording medium, and includes a fixing roller 31 and a pressure roller 32. The fixing roller 31 is rotatably provided by a driving unit (not shown), and fixes an unfixed toner image carried on the recording medium to the recording medium by heating and melting the constituent toner. A heating unit (not shown) is provided inside the fixing roller 31. The heating unit heats the fixing roller 31 so that the surface of the fixing roller 31 reaches a predetermined temperature (hereinafter also referred to as “heating temperature”). For example, a heater or a halogen lamp can be used as the heating means. The heating means is controlled by fixing condition control means described later. The control of the heating temperature by the fixing condition control means will be described in detail later.

  A temperature detection sensor (not shown) is provided near the surface of the fixing roller 31, and the temperature detection sensor detects the surface temperature of the fixing roller 31. The detection result by the temperature detection sensor is written in the storage unit of the control means described later. The pressure roller 32 is provided so as to be in pressure contact with the fixing roller 31 and is supported so as to be driven to rotate by the rotation drive of the pressure roller 32. When the toner is melted by heat from the fixing roller 31 and the toner image is fixed on the recording medium, the pressure roller 32 presses the toner and the recording medium to assist the fixing of the toner image onto the recording medium. A pressure contact portion between the fixing roller 31 and the pressure roller 32 is a fixing nip portion.

  According to the fixing unit 104, the recording medium onto which the toner image is transferred by the transfer unit 103 is sandwiched between the fixing roller 31 and the pressure roller 32, and the toner image is recorded under heating when passing through the fixing nip portion. By being pressed against the medium, the toner image is fixed on the recording medium and an image is formed.

  The recording medium supply unit 105 includes an automatic paper feed tray 35, a pickup roller 36, transport rollers 37 a and 37 b, a registration roller 38, and a manual paper feed tray 39. The automatic paper feed tray 35 is a container-like member that is provided in the lower part of the image forming apparatus 100 in the vertical direction and stores a recording medium. Examples of the recording medium include plain paper, color copy paper, overhead projector sheet, and postcard. The pickup roller 36 takes out the recording medium stored in the automatic paper feed tray 35 one by one, and feeds it to the paper transport path C1. The conveyance rollers 37 are a pair of roller members provided so as to be in pressure contact with each other, and convey the recording medium toward the registration rollers 38. The registration rollers 38 are a pair of roller members provided so as to be in pressure contact with each other, and the recording medium fed from the conveyance roller 37a is used to convey the toner image carried on the intermediate transfer belt 25 to the transfer nip portion. Synchronously, it is fed to the transfer nip. The manual paper feed tray 39 is a device that takes a recording medium into the image forming apparatus 100 by a manual operation, and the recording medium taken from the manual paper feed tray 39 passes through the paper conveyance path C2 by the conveyance roller 37b. Then, it is fed to the registration roller 38. According to the recording medium supply means 105, the toner image carried on the intermediate transfer belt 25 is conveyed to the transfer nip portion of the recording medium supplied one by one from the automatic paper feed tray 35 or the manual paper feed tray 39. In synchronism with this, the sheet is fed to the transfer nip portion.

  The discharge unit 106 includes a conveyance roller 37 c, a discharge roller 40, and a discharge tray 41. The conveyance roller 37 c is provided on the downstream side of the fixing nip portion in the sheet conveyance direction, and conveys the recording medium on which the image is fixed by the fixing unit 104 toward the discharge roller 40. The discharge roller 40 discharges the recording medium on which the image is fixed to a discharge tray 41 provided on the upper surface in the vertical direction of the image forming apparatus 100. The discharge tray 41 stores a recording medium on which an image is fixed.

The image forming apparatus 100 includes a control unit (not shown). For example, the control unit is provided in an upper part of the internal space of the image forming apparatus 100 and includes a storage unit, a calculation unit, and a control unit. The storage unit of the control unit stores various setting values via an operation panel (not shown) arranged on the upper surface of the image forming apparatus 100, detection results from sensors (not shown) arranged at various locations inside the image forming apparatus 100, and external Image information from the device is input. In addition, programs for executing various means are written. Examples of the various means include a recording medium determination unit, an adhesion amount control unit, and a fixing condition control unit. As the storage unit, those commonly used in this field can be used, and examples thereof include a read only memory (ROM), a random access memory (RAM), and a hard disk drive (HDD). As the external device, an electric / electronic device that can form or acquire image information and can be electrically connected to the image forming apparatus 100 can be used. For example, a computer, a digital camera, a television, a video recorder, a DVD recorder HD DVD, Blu-ray disc recorder, facsimile device, portable terminal device and the like. The arithmetic unit takes out various data (image formation command, detection result, image information, etc.) written in the storage unit and programs of various means, and performs various determinations. The control unit sends a control signal to the corresponding device according to the determination result of the calculation unit, and performs operation control. The control unit and the calculation unit include a processing circuit realized by a microcomputer, a microprocessor, or the like provided with a central processing unit (CPU). The control means includes a main power supply together with the processing circuit described above, and the power supply supplies power not only to the control means but also to each device in the image forming apparatus 100.

5. Fixing Device FIG. 8 is a schematic diagram schematically showing the developing device 14 provided in the image forming apparatus 100 shown in FIG. The developing device 14 includes a developing tank 20 and a toner hopper 21. The developing tank 20 is disposed so as to face the surface of the photosensitive drum 11, and supplies and develops a toner to an electrostatic latent image formed on the surface of the photosensitive drum 11 to form a visible toner image. It is a shaped member. The developing tank 20 accommodates toner in its internal space and accommodates roller members such as the developing roller 50, the supply roller 51, and the stirring roller 52, and rotatably supports them. Moreover, you may accommodate a screw member instead of a roller-shaped member. The developing device 14 of this embodiment stores the toner of the above-described embodiment in the developing tank 20 as toner.

  An opening 53 is formed on a side surface of the developing tank 20 facing the photosensitive drum 11, and a developing roller 50 is rotatably provided at a position facing the photosensitive drum 11 through the opening 53. The developing roller 50 is a roller-like member that supplies toner to the electrostatic latent image on the surface of the photosensitive drum 11 at the pressure contact portion or the closest portion to the photosensitive drum 11. When supplying the toner, a potential having a polarity opposite to the charging potential of the toner is applied to the surface of the developing roller 50 as a developing bias voltage (hereinafter simply referred to as “developing bias”). As a result, the toner on the surface of the developing roller 50 is smoothly supplied to the electrostatic latent image. Further, by changing the developing bias value, the toner amount supplied to the electrostatic latent image, that is, the toner adhesion amount of the electrostatic latent image can be controlled.

  The supply roller 51 is a roller-like member that faces the developing roller 50 and can be driven to rotate, and supplies toner around the developing roller 50.

  The agitation roller 52 is a roller-like member provided so as to be able to be driven to rotate while facing the supply roller 51, and feeds toner newly supplied from the toner hopper 21 into the developing tank 20 to the periphery of the supply roller 51. The toner hopper 21 is provided so that a toner replenishing port 54 provided at the lower part in the vertical direction and a toner receiving port 55 provided at the upper part in the vertical direction of the developing tank 20 communicate with each other. Add toner. Further, the toner may be directly supplied from each color toner cartridge without using the toner hopper 21.

  As described above, the developing device 14 develops the latent image using the two-component developer of the present invention. The two-component developer of the present invention can suppress a decrease in the toner charging ability of the carrier and can prevent filming of the photoreceptor, so that a high-definition and good toner image without uneven density can be stably formed on the photoreceptor. be able to.

  Further, the photosensitive drum 11 on which the latent image is formed, the charging unit 12 and the exposure unit 13 that form the latent image on the photosensitive drum 11, and the high-definition toner image is formed on the photosensitive drum 11 as described above. The image forming apparatus 100 is realized by including the developing device 14 of the present invention. By forming an image with such an image forming apparatus 100, it is possible to stably form a high-definition image having high definition and no density unevenness over a long period of time.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. In the following, “parts” and “%” mean “parts by weight” and “% by weight” unless otherwise specified. Values described in Examples and Comparative Examples were measured as follows.

[Glass transition temperature of binder resin and toner base particles]
Using a differential scanning calorimeter (trade name: DSC220, manufactured by Seiko Denshi Kogyo Co., Ltd.), according to Japanese Industrial Standard (JIS) K7121-1987, 1 g of a sample was heated at a heating rate of 10 ° C. per minute and a DSC curve was measured. did. Draw the endothermic peak corresponding to the glass transition of the obtained DSC curve at a point where the slope is maximum with respect to the straight line that extends the base line on the high temperature side to the low temperature side and the curve from the rising part of the peak to the vertex. The temperature at the intersection with the tangent was determined as the glass transition temperature (Tg).

[Softening temperature of binder resin]
In a flow characteristic evaluation apparatus (trade name: Flow Tester CFT-100C, manufactured by Shimadzu Corporation), a weight of 20 kgf / cm ² (9.8 × 10 ⁵ Pa) was applied with a weight to make a 1 g sample (nozzle diameter 1 mm). , 1 mm in length). Heating was performed at a heating rate of 6 ° C. per minute, and the temperature at which half of the sample flowed out from the die was determined and used as the softening temperature (Tm).

[Melting point of release agent]
Using a differential scanning calorimeter (trade name: DSC220, manufactured by Seiko Denshi Kogyo Co., Ltd.), 1 g of the sample is heated from a temperature of 20 ° C. to 200 ° C. at a heating rate of 10 ° C. per minute, and then rapidly cooled from 200 ° C. to 20 ° C. The operation was repeated twice and the DSC curve was measured. The temperature at the top of the endothermic peak corresponding to the melting of the DSC curve measured in the second operation was determined as the melting point of the release agent.

[Volume average particle diameter of toner base particles]
20 ml of a sample and 1 ml of sodium alkyl ether sulfate are added to 50 ml of an electrolytic solution (trade name: ISOTON-II, manufactured by Beckman Coulter, Inc.), and an ultrasonic dispersion device (trade name: desktop type dual frequency ultrasonic cleaner VS-D100). (Manufactured by As One Co., Ltd.) for 3 minutes at an ultrasonic frequency of 20 kHz to prepare a measurement sample. This sample for measurement was measured using a particle size distribution measuring device (trade name: Multisizer III, manufactured by Beckman Coulter, Inc.) under the conditions of aperture diameter: 100 μm, number of measured particles: 50000 count, and volume particle size distribution of sample particles. From this, the volume average particle diameter was determined.

[Average primary particle diameter of resin particles]
Using a laser diffraction / scattering particle size distribution measuring device (trade name: LA-950V2, manufactured by Horiba, Ltd.), the average primary particle size in the emulsion state of the raw material was measured.

[BET specific surface area of resin-coated toner]
By using a specific surface area measuring device (trade name: NOVA4200e, manufactured by QUANTACHROME INSTRUMENTS), a BET specific surface area (m ² / g) by a nitrogen gas adsorption method was measured. The smaller the measured irregularity of the particle surface, the smaller the value of the BET specific surface area, and the greater the irregularity of the particle surface, the greater the value of the BET specific surface area.

Example 1
[Toner mother particle production step S1]
The toner base particle raw material and the addition amount thereof are as follows.
Polyester resin (trade name: Diacron, manufactured by Mitsubishi Rayon Co., Ltd., glass transition temperature 55 ° C., softening temperature 130 ° C.) 87.5% by weight (100 parts by weight)
・ C. I. Pigment Blue 15: 3 5.0% by weight (5.7 parts by weight)
Release agent (carnauba wax, melting point 82 ° C.) 6.0% by weight (6.9 parts by weight)
-Charge control agent (trade name: Bontron E84, manufactured by Orient Chemical Co., Ltd.)
1.5% by weight (1.7 parts by weight)

  Each of the above components was premixed with a Henschel mixer (trade name: FM20C, manufactured by Mitsui Mining Co., Ltd.) and then melt-kneaded with a twin-screw extrusion kneader (trade name: PCM65, manufactured by Ikekai Co., Ltd.). This melt-kneaded product is coarsely pulverized with a cutting mill (trade name: VM-16, manufactured by Orient Co., Ltd.), then finely pulverized with a jet mill (manufactured by Hosokawa Micron Co., Ltd.), and further an air classifier (manufactured by Hosokawa Micron Co., Ltd.). To produce cyan toner base particles having a volume average particle diameter of 6.5 μm and a glass transition temperature of 56 ° C.

[Resin Particle Preparation Step S2]
A polymer obtained by polymerizing styrene and butyl acrylate is freeze-dried, and styrene-butyl acrylate copolymer fine particles (glass transition temperature 72 ° C., softening temperature 126 ° C.) having a volume average particle diameter of 0.1 μm are obtained as resin particles. Obtained.

[Resin-coated toner production step S3]
A device equipped with a two-fluid nozzle, similar to the rotary stirring device 201 shown in FIG. 2, was used. For spraying means, a plasticizing liquid is metered into a two-fluid nozzle (trade name: HM-6 type, manufactured by Fuso Seiki Co., Ltd.) through a liquid feed pump (trade name: SP11-12, manufactured by FROM Co., Ltd.). We used what was connected to. The mounting angle of the two-fluid nozzle was set so that the angle formed between the liquid spraying direction and the powder flow direction was parallel (0 °). The supply rate of the plasticizing liquid and the liquid gas discharge rate were observed using a commercially available gas detector (trade name: XP-3110, manufactured by Shin Cosmos Electric Co., Ltd.).

  The temperature adjusting jacket was provided on the entire surface of the circulation pipe and the wall surface of the rotating stirring chamber. A temperature sensor was attached to the powder channel. The temperature of the circulation pipe and the rotary stirring chamber was adjusted to 55 ° C. In the resin particle adhesion step S3b, the peripheral speed at the outermost periphery of the rotating stirring means of the hybridization system as the apparatus was set to 50 m / sec. In the first spraying step S3c and the film forming step S3d, the peripheral speed was set to 50 m / sec.

  After 400 parts by weight of toner base particles and 40 parts by weight of resin particles prepared in the above step are stirred and mixed in such a device for 5 minutes in the powder flow path (internal volume 26.79 L), the toner base particles and With the resin particles stirred and fluidized, ethanol (molecular weight 46.1, boiling point 78.3 ° C.) was sprayed as a plasticizing liquid. The liquid supply rate of ethanol from the two-fluid nozzle was 0.5 g / min, the supply amount of air as the carrier gas was 5 L / min, and sprayed for 30 minutes to form resin particles on the surface of the toner base particles. Thereafter, spraying of ethanol was stopped and the mixture was stirred for 5 minutes to obtain a resin-coated toner. Note that the amount of air supplied into the powder passage is adjusted by adjusting the amount of air supplied from the rotary shaft portion into the powder passage to 5 L / min, and the amount of air supplied from the two-fluid nozzle (5 L / min). ) To 10 L / min, and air was discharged out of the powder flow path at a discharge amount equal to the total supply amount (10 L / min).

[Spacer particle semi-embedding step S4]
The amount of spacer particles added is as follows. The addition amount indicates the amount when the resin-coated toner obtained in the resin-coated toner preparation step S3 is 100 parts by weight.
-Large particle size hydrophobic silica particles (spacer particles, trade name: KE-P10, manufactured by Nippon Shokubai Co., Ltd., average primary particle size 100 nm) 0.5 parts by weight

  Also in this step, the above-described apparatus equipped with a two-fluid nozzle according to the rotary stirring apparatus 201 of the present invention shown in FIG. The resin-coated toner and the spacer particles were agitated, and the temperature of the circulation tube and the rotating agitating chamber in the fluidized state was adjusted to 55 ° C. In the spacer particle adhesion step S4b, the peripheral speed at the outermost periphery of the rotating stirring means of the hybridization system was set to 50 m / sec. In the second spraying step S4c and the fixing step S4d, the peripheral speed was set to 50 m / sec. Further, the mounting angle of the two-fluid nozzle was set so that the spray angle was parallel (0 °).

  Each of the above components and the resin-coated toner obtained in the resin-coated toner preparation step S3 are stirred and mixed in the powder flow path (internal volume 26.79 L) for 5 minutes, and then the resin-coated toner and the spacer particles are stirred. In the fluidized state, ethanol (molecular weight 46.07) was sprayed as a plasticizing liquid. Spraying was performed for 20 minutes by setting the liquid supply rate of ethanol from the two-fluid nozzle to 0.5 g / min and the supply amount of air as a carrier gas to 5 L / min. Thereafter, the spraying of ethanol was stopped and the mixture was stirred for 5 minutes, whereby the spacer particles were semi-embedded in the coating layer on the surface of the resin-coated toner to obtain a toner in which the spacer particles were semi-buried. Note that the amount of air supplied into the powder passage is adjusted by adjusting the amount of air supplied from the rotary shaft portion into the powder passage to 5 L / min, and the amount of air supplied from the two-fluid nozzle (5 L / min). ) To 10 L / min, and air was discharged out of the powder flow path at a discharge amount equal to the total supply amount (10 L / min).

  Next, 100 parts by weight of toner in which spacer particles are semi-embedded, and small-diameter hydrophobic silica particles (external additive, trade name: RX-200, manufactured by Nippon Aerosil Co., Ltd., average primary particle size 12 nm) The toner of Example 1 was obtained by stirring 0 part by weight with a Henschel mixer (trade name: FM20C, manufactured by Mitsui Mining Co., Ltd.) for 3 minutes at a peripheral speed of 20 m / sec at the outermost periphery of the rotary stirring unit. It was.

(Example 2)
A toner of Example 2 was obtained in the same manner as in Example 1 except that the average primary particle diameter of the styrene-butyl acrylate copolymer fine particles produced in the resin particle preparation step S2 was adjusted to 0.05 μm. .

Example 3
The toner of Example 3 was obtained in the same manner as in Example 1 except that the average primary particle diameter of the styrene-butyl acrylate copolymer fine particles prepared in the resin particle preparation step S2 was adjusted to 0.5 μm. .

Example 4
A toner of Example 4 was obtained in the same manner as in Example 1 except that the average primary particle diameter of the styrene-butyl acrylate copolymer fine particles prepared in the resin particle preparation step S2 was adjusted to 1 μm.

(Example 5)
The plasticizing liquid used in each of the first spraying step S3c of the resin film toner preparation step S3 and the second spraying step S4c of the spacer particle semi-embedding step S4 was changed to methanol (molecular weight 32.0, boiling point 64.7 ° C.). A toner of Example 5 was obtained in the same manner as Example 1 except for the above.

(Example 6)
The plasticizing liquid used in each of the first spraying step S3c of the resin coating toner preparation step S3 and the second spraying step S4c of the spacer particle semi-embedding step S4 is 2-propanol (molecular weight 60.1, boiling point 82.4 ° C.). A toner of Example 6 was obtained in the same manner as Example 1 except for the change.

(Example 7)
The first primary spraying step S3c and the spacer particle semi-embedding step of the resin coating toner preparation step S3 are adjusted so that the average primary particle diameter of the styrene-butyl acrylate copolymer fine particles prepared in the resin particle preparation step S2 is 0.05 μm. The toner of Example 7 is obtained in the same manner as in Example 1 except that the plasticizing liquid used in each of the second spraying steps S4c of S4 is changed to methanol (molecular weight 32.0, boiling point 64.7 ° C.). It was.

(Example 8)
The average primary particle diameter of the styrene-butyl acrylate copolymer fine particles produced in the resin particle preparation step S2 is adjusted to 1 μm, and the first spraying step S3c in the resin film toner production step S3 and the spacer particle semi-embedding step S4 are performed. A toner of Example 8 was obtained in the same manner as in Example 1, except that the plasticizing liquid used in each of the second spraying steps S4c was changed to methanol (molecular weight 32.0, boiling point 64.7 ° C.).

Example 9
In the spacer particle semi-embedding step S4, the same procedure as in Example 1 was performed except that large-sized hydrophobic silica particles having an average primary particle size of 40 nm were used instead of large-sized hydrophobic silica particles having an average primary particle size of 100 nm. Thus, a toner of Example 9 was obtained.

(Example 10)
In the spacer particle semi-embedding step S4, the same procedure as in Example 1 was performed except that large-sized hydrophobic silica particles having an average primary particle size of 300 nm were used instead of large-sized hydrophobic silica particles having an average primary particle size of 100 nm. Thus, the toner of Example 10 was obtained.

(Example 11)
The styrene-butyl acrylate copolymer fine particles produced in the resin particle preparation step S2 are adjusted so that the average primary particle size is 0.05 μm, and in the spacer particle semi-embedding step S4, the average primary particle size is 100 nm. A toner of Example 11 was obtained in the same manner as in Example 1, except that large-sized hydrophobic silica particles having an average primary particle size of 40 nm were used in place of the hydrophobic silica particles.

(Example 12)
The styrene-butyl acrylate copolymer fine particles prepared in the resin particle preparation step S2 are adjusted so that the average primary particle size is 1 μm, and in the spacer particle semi-embedding step S4, the large primary particle size hydrophobicity having an average primary particle size of 100 nm A toner of Example 12 was obtained in the same manner as in Example 1 except that large-sized hydrophobic silica particles having an average primary particle size of 40 nm were used instead of the silica particles.

(Example 13)
The styrene-butyl acrylate copolymer fine particles produced in the resin particle preparation step S2 are adjusted so that the average primary particle size is 0.05 μm, and in the spacer particle semi-embedding step S4, the average primary particle size is 100 nm. A toner of Example 13 was obtained in the same manner as in Example 1 except that large-sized hydrophobic silica particles having an average primary particle size of 300 nm were used instead of the hydrophobic silica particles.

(Example 14)
The styrene-butyl acrylate copolymer fine particles prepared in the resin particle preparation step S2 are adjusted so that the average primary particle size is 1 μm, and in the spacer particle semi-embedding step S4, the large primary particle size hydrophobicity having an average primary particle size of 100 nm A toner of Example 14 was obtained in the same manner as in Example 1, except that large-sized hydrophobic silica particles having an average primary particle size of 300 nm were used in place of the silica particles.

(Example 15)
Example except that the peripheral speed at the outermost periphery of the rotating stirring means of the hybridization system in the spacer particle attaching step S4b, the second spraying step S4c and the immobilizing step S4d in the spacer particle semi-embedding step S4 is changed to 60 m / sec. In the same manner as in Example 1, a toner of Example 15 was obtained.

(Example 16)
Example except that the peripheral speed at the outermost periphery of the rotating stirring means of the hybridization system in the spacer particle adhering step S4b, the second spraying step S4c and the immobilizing step S4d in the spacer particle semi-embedding step S4 is changed to 30 m / sec. In the same manner as in Example 1, a toner of Example 16 was obtained.

(Example 17)
In the spacer particle semi-embedding step S4, a large particle size hydrophobic silica particle having an average primary particle size of 40 nm is used instead of the large particle size hydrophobic silica particle having an average primary particle size of 100 nm. In the same manner as in Example 1, except that the peripheral speed at the outermost periphery of the rotating stirring means of the hybridization system in the particle adhering step S4b, the second spraying step S4c, and the immobilizing step S4d was changed to 60 m / sec. 17 toners were obtained.

(Example 18)
In the spacer particle semi-embedding step S4, a large particle size hydrophobic silica particle having an average primary particle size of 300 nm is used in place of the large particle size hydrophobic silica particle having an average primary particle size of 100 nm. In the same manner as in Example 1, except that the peripheral speed at the outermost periphery of the rotating stirring means of the hybridization system in the particle adhering step S4b, the second spraying step S4c, and the immobilizing step S4d was changed to 30 m / sec. 18 toners were obtained.

(Example 19)
A toner of Example 19 was obtained in the same manner as in Example 1, except that the small particle size hydrophobic silica particles were not added as the external additive.

(Comparative Example 1)
Comparative Example 1 is the same as Example 1 except that the spray liquid was not sprayed in each of the first spraying step S3c of the resin coating toner preparation step S3 and the second spraying step S4c of the spacer particle semi-embedding step S4. A toner was obtained.

(Comparative Example 2)
A toner of Comparative Example 2 was obtained in the same manner as in Example 1 except that the temperature in the powder flow path was not adjusted in the resin coating toner production step S3.

(Comparative Example 3)
A toner of Comparative Example 3 was obtained in the same manner as in Example 1 except that the temperature adjustment in the powder channel was not performed in the spacer particle semi-embedding step S4.

(Comparative Example 4)
A toner of Comparative Example 4 was obtained in the same manner as in Example 1 except that the temperature in the powder channel was not adjusted in the resin coating toner preparation step S3 and the spacer particle semi-embedding step S4.

(Comparative Example 5)
A toner of Comparative Example 5 was obtained in the same manner as in Example 1 except that the average primary particle diameter of the styrene-butyl acrylate copolymer fine particles produced in the resin particle preparation step S2 was adjusted to 0.04 μm. .

(Comparative Example 6)
A toner of Comparative Example 6 was obtained in the same manner as in Example 1 except that the average primary particle diameter of the styrene-butyl acrylate copolymer fine particles produced in the resin particle preparation step S2 was adjusted to 1.5 μm. .

(Comparative Example 7)
In the first spraying step S3c of the resin coating toner preparation step S3, 15 g of ethanol is injected as a spraying means for 30 minutes using a syringe instead of using a liquid feed pump and a two-fluid nozzle, and the spacer particle semi-embedding step S4 is performed. 2 In the spraying step S4c, a toner of Comparative Example 7 was obtained in the same manner as in Example 1 except that 10 g of ethanol was added in 20 minutes using a syringe instead of using a liquid feed pump and a two-fluid nozzle as spraying means. It was.

(Comparative Example 8)
In the resin coating toner preparation step S3 and the spacer particle semi-embedding step S4, the sprayed and gasified ethanol is not easily discharged from the through hole and the gas discharge portion, and is flowed to the two-fluid nozzle so as to fill the powder flow path. Except that the air flow rate of the carrier gas is lowered to 1 L / min, the air flow rate flowing from the rotating shaft portion into the apparatus is adjusted to 9 L / min, and the air is discharged out of the powder flow path at 10 L / min in total. In the same manner as in Example 1, a toner of Comparative Example 8 was obtained.

(Comparative Example 9)
The plasticizing liquid used in each of the first spraying step S3c of the resin coating toner preparation step S3 and the second spraying step S4c of the spacer particle semi-embedding step S4 is 1-propanol (molecular weight 60.1, boiling point 97.2 ° C.). A toner of Comparative Example 9 was obtained in the same manner as Example 1 except for the change.

(Comparative Example 10)
The plasticizing liquid used in each of the first spraying step S3c of the resin coating toner preparation step S3 and the second spraying step S4c of the spacer particle semi-embedding step S4 is tetrahydrofuran (THF, molecular weight 72.1, boiling point 66.0 ° C.). The toner of Comparative Example 10 was obtained in the same manner as in Example 1 except that.

(Comparative Example 11)
In the spacer particle semi-embedding step S4, the same procedure as in Example 1 was performed except that large-sized hydrophobic silica particles having an average primary particle size of 30 nm were used instead of large-sized hydrophobic silica particles having an average primary particle size of 100 nm. Thus, a toner of Comparative Example 11 was obtained.

(Comparative Example 12)
In the spacer particle semi-embedding step S4, the same procedure as in Example 1 was performed except that large-sized hydrophobic silica particles having an average primary particle size of 350 nm were used instead of large-sized hydrophobic silica particles having an average primary particle size of 100 nm. Thus, a toner of Comparative Example 12 was obtained.

(Preparation of two-component developer)
The toners of Examples 1 to 18 and Comparative Examples 1 to 12 thus prepared and a silicone-coated ferrite core carrier having a volume average particle diameter of 45 μm were prepared and mixed so that the toner concentration would be 7% by weight. A component developer was prepared.

  For the toners of Examples 1 to 18 and Comparative Examples 1 to 12 obtained as described above, the yield, the embedded state of the spacer particles, the cleaning property, the fluidity, the transfer efficiency, and the charging stability were as follows. evaluated. Regarding the evaluation items excluding the yield and the embedded state of the external additive, the two-component developer produced as described above was replaced with a commercially available copying machine having a two-component developing device (trade name: MX-4500FN, Sharp Corporation). Evaluation was carried out by setting to a company) and developing.

[yield]
By calculating the yield of the resin-coated toner and the yield of the toner obtained in the spacer particle fixing step by the following formulas (3) and (4), and substituting those yields into the following formula (5), The toner yield was calculated.
Resin-coated toner yield = {weight of recovered resin-coated toner /
(Weight of toner base particles + weight of resin particles)} × 100 (3)
Yield of toner after external addition = {weight of recovered toner after external addition /
(Weight of collected resin film toner +
Weight of spacer particles and external additives)} × 100 (4)
Toner yield = {(resin-coated toner yield / 100) ×
(Yield of toner after external addition / 100)} × 100 (5)

The evaluation criteria are as follows.
A: Very good. The calculated toner yield is 90% or more.
○: Good. The calculated toner yield is 80% or more and less than 90%.
X: Defect. The calculated toner yield is less than 80%.

[Built-in state]
In order to evaluate the embedded state of the spacer particles, using a microtome equipped with diamond teeth, the cured product obtained by embedding the toner in a room temperature curable epoxy resin was made into an ultrathin section of about 100 μm, and transmission electron The cross section of the toner was observed at 20000 times with a microscope (TEM, trade name: H-8100, manufactured by Hitachi, Ltd.). As the embedded state of the spacer particles, there are a state in which the spacer particles are attached to the toner surface, a state in which the spacer particles are semi-embedded, and a state in which the spacer particles are completely embedded in the coating layer.

The evaluation criteria are as follows.
○: Good. The number of spacer particles semi-buried in the coating layer of the resin coating toner is 95 or more out of 100 measurements.
X: Defect. The number of spacer particles semi-embedded in the coating layer of the resin coating toner is 94 or less out of 100 measurements.

[Cleanability]
The two-component developer was set in the copying machine, and after 1,000 sheets were continuously printed at a printing rate of 5%, it was visually confirmed whether filming had occurred on the surface of the photoreceptor.

The evaluation criteria are as follows.
○: Good. No toner adheres to the photoreceptor and no filming is observed.
X: Defect. Cloudiness occurs on the surface of the photoreceptor, and filming is observed.

[Liquidity]
JIS K5101-12-1 (general test method for measuring the apparent density or apparent specific volume of a pigment and an extender pigment by the standing method) using a bulk specific gravity measuring instrument (JIS bulk specific gravity measuring instrument, manufactured by Tsutsui Richemical Instruments Co., Ltd.) The fluidity was evaluated according to It shows that fluidity | liquidity is so favorable that a bulk specific gravity value is large.

The evaluation criteria are as follows.
○: Good. The bulk specific gravity value is 0.38 g / cm ³ or more.
X: Defect. The bulk specific gravity value is less than 0.38 g / cm ³ .

[Transfer efficiency]
Development was performed with the two-component developer set in the copying machine. The transfer efficiency was calculated according to the following formula (6) from the ratio of the latter to the former by measuring the weight of the toner on the photoreceptor before transfer and the weight of the toner transferred onto the paper surface.
Transfer efficiency (%) = (weight of toner transferred on paper /
Weight of toner on photoconductor before transfer) × 100 (6)

The evaluation criteria are as follows.
A: Very good. Transfer efficiency is 95% or more.
○: Good. The transfer efficiency is 90% or more and less than 95%.
X: Defect. Transfer efficiency is less than 90%.

[Charging stability]
The two-component developer is set in the copying machine, an aging test is performed by continuous image printing with a printing rate of 5%, and the toner charge amount difference ΔQc (μC / g) between the initial printing and 10,000 printing is calculated. Asked.

The evaluation criteria are as follows.
○: Good. The charge amount difference ΔQc is 5 μC / g or less.
X: Defect. The charge amount difference ΔQc exceeds 5 μC / g.

[Comprehensive evaluation]
A comprehensive evaluation was performed based on the evaluation results of the yield, the buried state, the cleaning property, the fluidity, the transfer efficiency, and the charging stability.

The overall evaluation criteria are as follows.
○: Good. The evaluation results of the above evaluation items (all 6 items) are “◎” or “◯”, respectively, and “x” is not included.
X: Defect. “×” is included in the evaluation results of the above evaluation items (all six items).

  Table 1 shows conditions, toner evaluation results, and comprehensive evaluation results in the production methods of Examples and Comparative Examples.

(Discussion)
As shown in Table 1, the toners of the examples had good results in all evaluations.

  In Comparative Example 1 in which the plasticizing liquid was not sprayed, the BET specific surface area of the resin-coated toner could not be set to a desired value, and the spacer particles could not be stably semi-embedded.

  In Comparative Example 2 in which the temperature was not adjusted during the resin coating toner preparation process, the uniformity of the resin coating toner decreased as indicated by the value of the BET specific surface area of the resin coating toner, and a toner with high sphericity was obtained. As a result, transfer efficiency decreased. That is, the transfer efficiency was lowered due to the film state of the resin-coated toner.

  In Comparative Examples 3 and 4 in which appropriate temperature adjustment was not performed, the spacer particles were not stably fixed to the coating layer, and the cleaning property and transfer efficiency were lowered.

  In Comparative Example 7 in which liquid spraying was performed with a syringe, the yield decreased. Further, as indicated by the value of the BET specific surface area of the resin-coated toner, the coating uniformity of the resin-coated toner was reduced, and a toner having high sphericity could not be obtained, so that the transfer efficiency was lowered.

  In Comparative Example 11, since the particle diameter of the spacer particles was too small, the spacer effect was not sufficiently exhibited, and the transfer efficiency was lowered.

  In Comparative Example 12, even when the BET specific surface area of the resin-coated toner is within the range specified in claim 1, since the particle diameter of the spacer particles is too large, the spacer particles are detached over time and the charging stability is lowered. did.

DESCRIPTION OF SYMBOLS 1 Toner particle 2 Toner mother particle 3 Coating layer 4 External additive 5 Spacer particle

Claims (8)

A first mixing step of mixing the toner base particles and resin particles having an average primary particle diameter of 0.05 μm or more and 1 μm or less to attach the resin particles to the surface of the toner base particles to obtain a resin particle-attached toner;
Rotating stirring means for generating a circulating air flow, a rotating stirring chamber for storing the rotating stirring means, a circulation pipe connected to the rotating stirring chamber, and at least part of a powder flow path including the rotating stirring chamber and the circulation pipe Temperature adjusting means for adjusting the temperature in the rotary stirring means and the powder flow path to a predetermined temperature, and a plasticizing liquid provided in the circulation pipe for plasticizing the toner mother particles and the resin particles toward the circulation pipe. A rotary stirring device including a spraying means for spraying, applying an impact force to the toner adhering to the resin particles, adjusting the temperature in the rotary stirring means and the powder flow path to a predetermined temperature by the temperature adjusting means, and spraying means By spraying the plasticizing liquid toward the inside of the circulation pipe, the resin particles adhering to the resin particle adhesion toner are fused, and the BET specific surface area is 0.9 m ² / g or more and 1.8 m ² / g or less. A resin coating A film forming step for obtaining toner;
A second mixing step of mixing the resin-coated toner and spacer particles having an average primary particle diameter of 40 nm or more and 300 nm or less to attach the spacer particles to the surface of the resin-coated toner to obtain a spacer particle-attached toner;
Using the rotary stirring device, the temperature adjusting means adjusts the temperature in the rotary stirring means and the powder flow path to a predetermined temperature, and the spraying means sprays the plasticizing liquid toward the inside of the circulation pipe, thereby adhering spacer particles. And a spacer particle fixing step of fixing spacer particles adhering to the toner.   2. The toner manufacturing method according to claim 1, wherein the spraying means includes a liquid feeding pump, and a plasticizing liquid having a constant flow rate is sprayed into the circulation pipe by the liquid feeding pump.   The method for producing toner according to claim 1, wherein the rotary stirring device includes a mechanism for discharging the plasticized liquid gasified in the powder flow path to the outside of the device at a constant concentration.   The plasticizing liquid contains alcohol, and the boiling point of the alcohol is not less than a temperature 20 ° C lower than the glass transition temperature of the resin particles and not more than 20 ° C higher than the glass transition temperature of the resin particles. 4. The method for producing a toner according to any one of 3 above.   A toner produced by the toner production method according to claim 1.   A two-component developer comprising the toner according to claim 5 and a carrier.   A developing device that performs development using the two-component developer according to claim 6. An image carrier on which a latent image is formed;
A latent image forming means for forming a latent image on the image carrier;
An image forming apparatus comprising: the developing device according to claim 7.

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