JP4676223B2 - Toner and method for producing the same, developer, toner container, process cartridge, image forming apparatus, and image forming method - Google Patents

Description

  The present invention relates to a toner suitable as a toner used in electrophotography, electrostatic recording method, electrostatic printing method, and the like, an efficient production method thereof, a developer using the toner, a container containing the toner, and a process The present invention relates to a cartridge, an image forming apparatus, and an image forming method.

  In general, an electrophotographic method is an electrostatic latent image forming step in which an electrostatic latent image is formed on a photoreceptor layer using a photoconductive material by using various means, and a toner image is developed using toner. A developing step for forming, a transferring step for transferring the toner image to a recording medium such as paper, a fixing step for fixing the toner image transferred to the recording material to the recording material by heating, pressure, thermal pressure, solvent vapor, or the like; This includes a cleaning process for removing toner remaining on the body layer.

  The toner used in the electrophotographic method is required to be manufactured by a method that saves energy and has little influence on the environment. As a current toner production method, a melt kneading and pulverizing method has been conventionally known, but in recent years, a polymerization method (suspension method, emulsification method, dispersion method, etc.) in a liquid solvent is mainly used. It has become. The polymerized toner produced by such a polymerization method has a form capable of effectively expressing a desired function as expressed by names such as capsule toner and core-shell toner from the viewpoint of environmental issues in recent years. What you have is provided.

  In the toner production method by the melt pulverization method, in order to ensure uniformity of the shape of the obtained toner, it is important how to uniformly disperse and pulverize each constituent material. Basically, the shape of the pulverized toner is indefinite, and the pulverized cross section is random. Therefore, it is very difficult to control the shape and structure. In addition, when many colorants, mold release agents, charge control agents, etc. are added, during the pulverization step, these added ones are easily exposed on the surface side by cleaving at the crystal plane, and within each particle. There is a problem that the toner performance such as the charging performance of the toner tends to deteriorate.

  On the other hand, in the method for producing a toner by the polymerization method, a toner having good performance can be produced as compared with the pulverization method, but it is difficult to form arbitrary droplets in a dispersion medium, and the material to be used However, the toner produced by the emulsion polymerization method has a problem that the releasability, charging performance and the like are unevenly distributed due to the bias of the components forming the toner.

Therefore, in the polymerized toner, in order to obtain a uniform toner with a sufficient amount of a charge control agent, a release agent, and the like, for example, Patent Document 1 discloses a hydrophilic part, a hydrophobic part, and a gap between them in one molecule. Before conducting emulsion polymerization or soap-free emulsion polymerization using a polymerization initiator having a structure having a polymerization initiation site on the surface, at least one of a charge control agent and a wax is dispersed in water with the polymerization initiator. Thus, a method for producing a toner including a step of preparing an aqueous dispersion having micelles containing these components has been proposed.
However, even with the toner manufacturing method described in Patent Document 1, it is difficult to achieve sufficient uniform dispersion and uniform adhesion of the charge control agent, wax, and the like, and the development performance thereof is sufficiently satisfactory in terms of lifetime and the like. It was not a thing.

  Therefore, it is possible to form a coating layer with an arbitrary material on the toner base particles produced by the conventional method, and to impart more uniform charging performance, surface properties, etc. At present, no technology has been provided that can sufficiently solve the problems caused by the uneven distribution of the above.

JP 2003-21933 A

  An object of the present invention is to solve the conventional problems and achieve the following objects. That is, the present invention has a coating layer formed on the surface by at least one of a supercritical fluid and a subcritical fluid, is excellent in releasability, charging performance, surface properties, etc., has no pinhole, and is thin. Toner having uniform coating layer and manufacturing method thereof efficiently and less burden on environment, developer, container containing toner, process cartridge, image forming apparatus capable of improving image quality using the toner, and An object is to provide an image forming method.

  As a result of intensive studies in view of the above problems, the present inventors have obtained the following knowledge. That is, a toner functional substance such as a resin, a release agent, and a charge control agent is dissolved in at least one of a supercritical fluid and a subcritical fluid as a coating material on the surface of the toner base particles, and the toner base in the fluid. By treating the particles for a certain period of time, the surface of the toner base particles can be provided with excellent functions such as releasability and chargeability, and a thin and uniform coating layer can be formed without pinholes. This is the knowledge.

The present invention is based on the above findings of the present inventors, and means for solving the above problems are as follows. That is,
<1> A toner base particle manufacturing process for manufacturing toner base particles including at least resin fine particles, and a toner functional substance is attached to or coated on the surface of the toner base particles using at least one of a supercritical fluid and a subcritical fluid. And a coating layer forming step of forming a coating layer.
<2> The method for producing a toner according to <1>, wherein at least one of the supercritical fluid and the subcritical fluid can dissolve the toner functional substance without dissolving the toner base particles.
<3> The coating layer according to any one of <1> to <2>, wherein the coating layer is formed by depositing a toner functional substance dissolved in at least one of a supercritical fluid and a subcritical fluid. A toner manufacturing method.
<4> The toner production method according to any one of <1> to <3>, wherein the coating layer is formed on a part or all of the surface of the toner base particles.
<5> The coating layer forming step is a resin coating layer in which the toner functional substance is a resin, and a resin coating layer is formed by contacting at least one of a supercritical fluid and a subcritical fluid, toner base particles, and a resin. The method for producing a toner according to any one of <1> to <4>, including a forming step.
<6> In the coating layer forming step, the toner functional substance is a charge control agent, and at least one of a supercritical fluid and a subcritical fluid, toner base particles, and a charge control agent are brought into contact with each other to form a charge control agent coating layer. The method for producing a toner according to any one of <1> to <5>, further including a charge control agent coating layer forming step of forming the toner.
<7> In the coating layer forming step, the toner functional substance is a release agent, and at least one of the supercritical fluid and the subcritical fluid, the toner base particles, and the release agent are brought into contact with each other to release the release agent coating layer. The method for producing a toner according to any one of <1> to <6>, further including a release agent coating layer forming step of forming a toner.
<8> The method for producing a toner according to any one of <1> to <7>, wherein at least one of the supercritical fluid and the subcritical fluid is either a simple substance or a mixture.
<9> The method for producing a toner according to any one of <1> to <8>, wherein at least one of the supercritical fluid and the subcritical fluid contains at least carbon dioxide.
<10> The method for producing a toner according to any one of <1> to <9>, wherein at least one of the supercritical fluid and the subcritical fluid includes an entrainer.
<11> The toner production method according to <10>, wherein the content of the entrainer is 0.1 to 10% by mass.
<12> The toner production method according to any one of <10> to <11>, wherein the entrainer is a polar organic solvent.
<13> A toner produced by the method for producing a toner according to any one of <1> to <12>.
<14> A developer comprising the toner according to <13>.
<15> A toner-containing container filled with the toner according to <13>.
<16> An electrostatic latent image carrier and development means for developing the electrostatic latent image formed on the electrostatic latent image carrier using the toner according to <13> to form a visible image. It is a process cartridge characterized by having at least.
<17> An electrostatic latent image carrier, an electrostatic latent image forming unit that forms an electrostatic latent image on the electrostatic latent image carrier, and the toner according to <13> And developing means for forming a visible image by using the developing means, transferring means for transferring the visible image to a recording medium, and fixing means for fixing the transferred image transferred to the recording medium. The image forming apparatus.
<18> An electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier, and developing the electrostatic latent image with the toner according to <13> to form a visible image. An image forming method comprising: a developing step for forming; a transferring step for transferring the visible image to a recording medium; and a fixing step for fixing the transferred image transferred to the recording medium.

  The toner manufacturing method of the present invention includes a toner base particle manufacturing step for manufacturing toner base particles containing at least resin fine particles, and a toner function on the surface of the toner base particles using at least one of a supercritical fluid and a subcritical fluid. A coating layer forming step of forming a coating layer by adhering or coating the active substance. In the method for producing a toner of the present invention, in the coating layer forming step, a toner functional substance is adhered or coated on the surface of the toner base particles using at least one of the supercritical fluid and the subcritical fluid. A coating layer is formed. As a result, functions such as excellent releasability and charge controllability can be imparted, and a toner having no pinholes and having a thin and uniform coating layer can be obtained.

  Since the toner of the present invention is produced by the toner production method of the present invention, it is excellent in charging performance and surface properties.

  Since the developer of the present invention contains the toner of the present invention, when an image is formed by electrophotography using the developer, a high quality image with excellent charging performance and high image density can be obtained. It is done.

  Since the toner-containing container of the present invention contains the toner of the present invention, when an image is formed by electrophotography using the toner stored in the toner-containing container, the releasability, charging performance, and the like are improved. Excellent and high-quality images with high image density and high sharpness can be obtained.

  The process cartridge of the present invention comprises an electrostatic latent image carrier, and developing means for developing the electrostatic latent image formed on the electrostatic latent image carrier using the toner of the present invention to form a visible image. At least. As a result, it can be attached to and detached from the image forming apparatus, is excellent in convenience, and uses the toner of the present invention, so that it has excellent releasability, charging performance, etc., and has high image density and high sharpness. Is obtained.

  The image forming apparatus of the present invention includes an electrostatic latent image carrier, an electrostatic latent image forming unit that forms an electrostatic latent image on the electrostatic latent image carrier, and the electrostatic latent image of the present invention. The image forming apparatus includes at least a developing unit that forms a visible image by developing with toner, a transfer unit that transfers the visible image to a recording medium, and a fixing unit that fixes the transferred image transferred to the recording medium. In the image forming apparatus of the present invention, the electrostatic latent image forming unit forms an electrostatic latent image on the electrostatic latent image carrier. The developing means develops the electrostatic latent image using the toner of the present invention to form a visible image. The transfer means transfers the visible image to a recording medium. The fixing unit fixes the transferred image transferred to the recording medium. As a result, a high quality image with excellent image releasability and charging performance and high image density and high sharpness can be obtained.

  The image forming method of the present invention includes an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier, and the electrostatic latent image is developed using the toner of the present invention to be visible. It includes at least a developing step for forming an image, a transfer step for transferring the visible image to a recording medium, and a fixing step for fixing the transferred image transferred to the recording medium. In the image forming method of the present invention, an electrostatic latent image is formed on the electrostatic latent image carrier in the electrostatic latent image forming step. In the developing step, the electrostatic latent image is developed using the toner of the present invention to form a visible image. In the transfer step, the visible image is transferred to a recording medium. In the fixing step, the transferred image transferred to the recording medium is fixed. As a result, a high quality image with excellent image releasability and charging performance and high image density and high sharpness can be obtained.

  According to the present invention, various problems in the prior art can be solved, and a coating layer is formed on the surface of the toner base particles by at least one of a supercritical fluid and a subcritical fluid, and excellent releasability and charging performance. A toner having no pinholes and having a thin and uniform coating layer, a production method thereof that is efficient and has a low environmental impact, and high image quality can be achieved using the toner. , A developer, a container containing toner, a process cartridge, an image forming apparatus, and an image forming method.

(Toner and toner production method)
The toner manufacturing method of the present invention includes a toner base particle manufacturing step and a coating layer forming step, and further includes other steps appropriately selected as necessary.
The coating layer forming step preferably includes at least one of a resin coating layer forming step, a charge control agent coating layer forming step, and a release agent coating layer forming step.
The toner of the present invention is obtained by the toner production method of the present invention.
Hereinafter, the details of the toner of the present invention will be clarified through the description of the toner production method of the present invention.

<Toner base particle manufacturing process>
The toner base particle manufacturing step is a step of manufacturing toner base particles containing at least resin fine particles. In the present invention, the “toner base particles” widely include those other than the final toner, and the resin fine particles as well as the resin fine particles themselves are added to the charge control agent coating layer, the release agent coating layer, the resin coating layer, and It is a concept including at least one of other layers formed.

The resin fine particles contained in the toner base particles are not particularly limited as long as they are resin fine particles used for image formation, and can be appropriately selected according to the purpose. For example, the resin fine particles can be obtained by a pulverization method or a polymerization method. Examples thereof include resin fine particles. There is no restriction | limiting in particular as this polymerization method, According to the objective, it can select suitably, For example, a suspension method, an emulsification method, a dispersion method etc. are mentioned.
The toner may be produced by a microencapsulation method (spray drying method, coacervation method, etc.), etc., in addition to the pulverization method and polymerization method.
As the resin fine particles, those appropriately synthesized may be used, or commercially available products may be used.

  The pulverization method is, for example, a method for producing the toner base particles by melting and kneading a material containing at least a binder resin, pulverizing, classifying, and the like. In the case of the pulverization method, the shape may be controlled by applying a mechanical impact force to the obtained toner base particles in order to increase the average circularity of the toner. In this case, the mechanical impact force can be applied to the toner base particles using a device such as a hybridizer or mechanofusion.

As the resin fine particles by the polymerization method, for example, vinyl resin, polyurethane resin, epoxy resin, polyester resin, polyamide resin, polyimide resin, silicon resin, phenol resin, melamine resin, urea resin, aniline resin, ionomer resin, polycarbonate resin, Etc. The vinyl resin is a polymer obtained by homopolymerizing or copolymerizing a vinyl monomer. For example, a styrene- (meth) acrylic ester resin, a styrene-butadiene copolymer, a (meth) acrylic acid-acrylic ester polymer. Styrene-acrylonitrile copolymer, styrene-maleic anhydride copolymer, styrene- (meth) acrylic acid copolymer, and the like.
Also formed with polystyrene, methacrylic acid ester, acrylic acid ester copolymer, silicone resin, benzoguanamine, nylon and other polycondensation resins, thermosetting resins, etc. obtained by soap-free emulsion polymerization, suspension polymerization, dispersion polymerization, etc. The fine resin particles thus obtained are suitable because of their sharp particle size distribution. Among these, the resin fine particles obtained by dispersion polymerization are preferable because of their sharper particle sizes. Further, if the toner is imparted with low-temperature fixability, resin fine particles made of a polyester resin or a polyol resin can be selected. That is, the resin can be selected in accordance with the design of the target toner base particles.

Here, the dispersion polymerization method will be specifically described.
First, a polymer compound dispersant that dissolves in the hydrophilic organic liquid is added to the hydrophilic organic liquid, and the polymer is dissolved in the hydrophilic liquid, but the resulting polymer is swollen by the hydrophilic liquid. Or hardly dissolve. One or more vinyl monomers are added to this to form particles. A reaction of growing in the above-described system using a polymer having a particle size distribution narrower than the target particle size in advance is also included. The monomer used for the growth reaction may be the same as that used to produce the seed particles, or may be another monomer, but the polymer must not be dissolved in the hydrophilic organic liquid. The polymer dispersion obtained by such a method can be used as it is in the subsequent coating layer forming step, which contributes to the simplification of the manufacturing process.

As the hydrophilic organic liquid, a liquid that dissolves the vinyl monomer to be used and does not dissolve the obtained resin fine particles (polymer particles) is used. Examples of the liquid include methyl alcohol, ethyl alcohol, modified ethyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, sec-butyl alcohol, tert-amyl alcohol, 3-pentanol and octyl alcohol. , Benzyl alcohol, cyclohexanol, furfuryl alcohol, alcohols such as ethylene glycol, glycerin, diethylene glycol, methyl cellosolve, cellosolve, isopropyl cellosolve, butyl cellosolve, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether And ether alcohols such as ether That. These organic liquids can be used singly or as a mixture of two or more. In addition, by using together with the above-mentioned alcohols and ether alcohols in organic liquids other than alcohols and ether alcohols, various SPs can be used under conditions that do not make the polymer particles soluble in organic liquids. By changing the value and changing the polymerization conditions, it is possible to suppress the size of the generated particles, the coalescence of the particles, and the generation of new particles.
Examples of the organic liquid include hydrocarbons such as hexane, octane, petroleum ether, cyclohexane, benzene, toluene, and xylene; halogenated hydrocarbons such as carbon tetrachloride, trichloroethylene, and tetrabromoethane; ethyl ether, dimethyl Ethers such as glycol, trioxane and tetrahydrofuran; acetals such as methylal and diethyl acetal; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexa; esters such as butyl formate, butyl acetate, ethyl propionate and cellosolve acetate Acids such as formic acid, acetic acid and propionic acid; sulfur and nitrogen-containing organic compounds such as nitropropene, nitrobenzene and dimethylamine; and water.
State in which SO ₄ ²⁻ , NO ₂ ⁻ , PO ₄ ³⁻ , Cl ⁻ , Na ⁺ , K ⁺ , Mg ²⁺ , Ca ²⁺ , and other inorganic ions are present in the solvent mainly composed of the hydrophilic organic liquid. The polymerization may be carried out at In addition, the average particle size, particle size distribution, drying conditions, and the like of the polymer particles can be adjusted by changing the type and composition of the mixed solvent at the start of polymerization, during polymerization, and at the end of polymerization.

  The polymer compound dispersant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid Acids such as fumaric acid, maleic acid or maleic anhydride; acrylic monomers; vinyl alcohol or ethers of vinyl alcohol; esters of vinyl alcohol and compounds containing a carboxyl group; acrylamide, methacrylamide, di Acetone acrylamide, or methylol compounds thereof; acid chlorides such as acrylic acid chloride and methacrylic acid chloride; compounds having a heterocyclic ring; homopolymers of various monomers such as; or copolymers thereof; polyoxyethylene resins , Celluloses, and the like.

  The polymer compound dispersant is appropriately selected depending on the hydrophilic organic liquid to be used, the target polymer particle seed and the seed particle manufacturing or the growth particle manufacturing. In view of sterically preventing the polymer particles, those having high affinity and adsorbability to the polymer particle surface and high affinity and solubility to the hydrophilic organic liquid are selected. Further, in order to enhance the repulsion between particles in a three-dimensional manner, a molecular chain having a certain length, particularly a molecular weight of 10,000 or more is preferable. However, if the molecular weight is too high, the viscosity of the liquid is remarkably increased, the operability and the stirrability are deteriorated, and the precipitation probability of the produced polymer on the particle surface varies. In addition, it is effective for stabilization to allow the monomer of the polymer compound dispersant mentioned above to coexist with the monomer constituting the intended polymer particle.

  In general, the amount of the polymer compound dispersant used in the production of seed particles varies depending on the type of monomer for forming the polymer particles, but is 0.1 to 10% by mass with respect to the hydrophilic organic liquid. Preferably, 1-5 mass% is more preferable. When the concentration of the polymer compound dispersant is low, the produced polymer particles have a relatively large diameter, and when the concentration is high, small particles are obtained. Is less effective in reducing the diameter.

  In addition, the use of inorganic compound fine powders and surfactants in combination with these polymer compound dispersants can further improve the stabilization of the produced polymer particles and the improvement of the particle size distribution. Polymerization may be carried out in the presence of these materials in a vinyl monomer solution or a seed particle dispersion added for the purpose of preventing coalescence of particles. Initially generated particles are stabilized by a distributed polymer dispersant that is equilibrated in the hydrophilic organic liquid and on the polymer particle surface, but significant amounts of unreacted vinyl monomer are present in the hydrophilic organic liquid. In some cases, it will be somewhat swollen and sticky and will agglomerate over the steric repulsion of the polymeric dispersion stabilizer.

  Furthermore, when the amount of monomers is extremely large with respect to the hydrophilic organic liquid, it does not precipitate unless the polymerization that completely dissolves the produced polymer proceeds to some extent. The state of precipitation in this case takes the form of forming a highly sticky lump. Therefore, the amount of the monomer with respect to the hydrophilic organic liquid when producing the fine resin particles is not particularly limited, and is somewhat different depending on the kind of the hydrophilic organic liquid, but is preferably 100% by mass or less, and more preferably 50% by mass or less.

As the polymerization initiator, a normal radical initiator soluble in the solvent to be used is used.
Examples of the polymerization initiator include azo polymerization initiators such as 2,2′-azobisisobutyronitrile and 2,2′-azobis (2,4-dimethylvaleronitrile); lauryl peroxide, benzoylperoxide Peroxide-based polymerization initiators such as oxide, tert-butyl peroctoate, potassium persulfate, etc., or a system in which sodium thiosulfate, amine, etc. are used in combination therewith are used.
As for the addition amount of the said polymerization initiator, 0.1-10 mass parts is preferable with respect to 100 mass parts of vinyl monomers. Polymerization is performed by completely dissolving the polymer dispersant in the hydrophilic organic liquid, and then adding one or more vinyl monomers, a polymerization initiator, etc., and stirring at a speed that makes the flow in the reaction vessel uniform. However, it is carried out by heating to a temperature corresponding to the dispersion rate of the polymerization initiator used. In addition, since the temperature at the initial stage of polymerization has a large influence on the particle size to be generated, it is preferable to increase the temperature to the polymerization temperature after adding the monomer and dissolve the polymerization initiator in a small amount of solvent.

  In the polymerization, it is preferable that oxygen in the reaction vessel is sufficiently expelled with an inert gas such as nitrogen gas or argon gas. If the oxygen purge is insufficient, fine particles may be easily generated.

  In order to perform the polymerization in a high polymerization rate region, a polymerization time of 5 to 40 hours is preferable. The polymerization rate can be increased by stopping the polymerization in a desired particle size and particle size distribution state, sequentially adding a polymerization initiator, or performing a reaction under high pressure.

Alternatively, the polymerization may be carried out in the presence of a compound having a large chain transfer constant for the purpose of adjusting the average molecular weight of the resin fine particles. Examples of the compound having a large chain transfer constant include a low molecular compound having a mercapto group, carbon tetrachloride, carbon tetrabromide, and the like.
There is no restriction | limiting in particular as a mass average molecular weight of the said resin fine particle, According to the objective, it can select suitably, For example, 1,000 or more are preferable, 2,000-10,000,000 are more preferable, 3, 000 to 1,000,000 is more preferable. When the mass average molecular weight is less than 1,000, the hot offset resistance may be deteriorated.

There is no restriction | limiting in particular as glass transition temperature (Tg) of the said resin fine particle, According to the objective, it can select suitably, For example, 30-70 degreeC is preferable and 40-65 degreeC is more preferable. When the glass transition temperature (Tg) is less than 30 ° C., the heat-resistant storage stability of the toner may deteriorate, and when it exceeds 70 ° C., the low-temperature fixability may not be sufficient.
The volume average particle diameter of the resin fine particles is preferably 3 to 12 μm, and more preferably 4 to 8 μm.

<Coating layer forming step>
The coating layer forming step is a step of forming a coating layer by attaching or coating a toner functional material on the surface of the toner base particles using at least one of a supercritical fluid and a subcritical fluid.

  The toner functional substance means a substance for exerting an electrophotographic developing function. For example, a charge control agent, a release agent, a coating resin, and the like are preferably used, and further fluidity is improved as necessary. Other toner functional substances such as a colorant, a cleaning property improver, and a colorant can be used.

  As the coating layer forming step, (1) the toner functional substance is a resin and a resin coating layer forming step for forming a resin coating layer, and (2) the toner functional substance is a charge control agent, and the charge control agent coating is performed. A charge control agent coating layer forming step for forming a layer, (3) a toner functional substance is a release agent, a release agent coating layer forming step for forming a release agent coating layer, and the like. There is no restriction | limiting in particular about the order to implement, It can combine suitably and can form each coating layer on the surface of a toner base particle. Details of these steps will be described later.

-Supercritical fluid and subcritical fluid-
The supercritical fluid has intermediate properties between gas and liquid, has properties such as fast mass transfer and heat transfer, low viscosity, and changes its temperature and pressure to change its density and dielectric constant. Means a fluid capable of continuously changing the solubility parameter, the free volume, etc. Furthermore, since the supercritical fluid has an extremely small interfacial tension as compared with an organic solvent, even a small undulation (surface) can follow and be wet with the supercritical fluid.
The supercritical fluid exists as a non-condensable high-density fluid in a temperature and pressure range that exceeds the limit (critical point) where gas and liquid can coexist, does not cause condensation even when compressed, and exceeds the critical temperature. And, as long as it is a fluid in a state equal to or higher than the critical pressure, there is no particular limitation and can be appropriately selected according to the purpose, but those having a low critical temperature and critical pressure are preferable, and the subcritical fluid is As long as it exists as a high-pressure liquid in the temperature and pressure region near the critical point, there is no particular limitation, and it can be appropriately selected according to the purpose.

Examples of the supercritical fluid or subcritical fluid include carbon monoxide, carbon dioxide, ammonia, nitrogen, water, methanol, ethanol, ethane, propane, 2,3-dimethylbutane, benzene, chlorotrifluoromethane, and dimethyl ether. Are preferable. Among these, carbon dioxide can easily create a supercritical state with a critical pressure of 7.3 MPa and a critical temperature of 31 ° C., and is nonflammable, inert, easy to handle, and non-aqueous, so that the toner base particles This is particularly preferred from the viewpoint that the surface can be hydrophobized.
The supercritical fluid or the subcritical fluid may be used alone or as a mixture of two or more.

  The critical temperature and critical pressure of the supercritical fluid are not particularly limited and may be appropriately selected depending on the intended purpose. However, the critical temperature is preferably −273 to 300 ° C., more preferably 0 to 200 ° C. preferable. Moreover, as said critical pressure, 5-100 MPa is preferable and 10-50 MPa is more preferable.

In the present invention, it is possible to perform coating layer formation (thin film formation, encapsulation, film thickness control, etc.) by actively utilizing the properties of the supercritical fluid or the subcritical fluid.
It is preferable that at least one of the supercritical fluid and the subcritical fluid can dissolve the toner functional substance without dissolving the toner base particles.
The coating layer is preferably formed by depositing a toner functional substance dissolved in at least one of a supercritical fluid and a subcritical fluid.
The coating layer is formed by controlling the solubility (controlled by temperature and pressure) of the toner functional substance as a solute in the supercritical fluid, and forming a uniform coating layer on the surface of the toner base particles (the surface of the resin fine particles). (Precipitation) can be performed. Specifically, the toner functional substance is dissolved or finely dispersed under conditions where the toner base particles (resin fine particles) do not dissolve, and then the pressure is reduced to deposit and fix the toner functional substance on the surface of the resin fine particles. A uniform coating layer is formed.
In addition, since the supercritical fluid can be easily separated from the target product and can be recovered and reused, it is possible to realize a revolutionary production method with a low environmental load that does not use a solvent.

  In addition to the supercritical fluid and the subcritical fluid, other fluids can be used in combination. The other fluid is preferably a fluid that can easily control the solubility of the toner constituting material. Specifically, methane, ethane, propane, ethylene, and the like are preferable.

  In addition to the supercritical fluid and the subcritical fluid, an entrainer (azeotropic agent) may be added. By the addition of the entrainer, the coating layer can be formed more easily. There is no restriction | limiting in particular as said entrainer, Although it can select suitably according to the objective, A polar organic solvent is preferable. Examples of the polar organic solvent include methanol, ethanol, propanol, butanol, hexane, toluene, ethyl acetate, chloroform, dichloromethane, ammonia, melamine, urea, thioethylene glycol, and the like. Among these, cleaning and removal aids such as chloroform are particularly preferable from the viewpoint of high resin solubility. By adding the chloroform, the precipitation effect of the toner functional substance on the surface of the toner base particles is increased. The supercritical fluid or subcritical fluid is preferably selected from the types that can dissolve the materials forming the various coating layers without dissolving the resin fine particles. In particular, a lower alcohol solvent exhibiting poor solvent properties at normal temperature and normal pressure is preferable for the toner base particles.

Examples of the entrainer include those in which the toner base particles (resin fine particles) to be used do not dissolve, or those that slightly swell, specifically the solubility parameter [SP value] and the resin fine particles to be used [SP value]. Is preferably 1.0 or more, more preferably 2.0 or more. For example, for styrene-acrylic resins, use alcohols such as methanol, ethanol, and n-propanol with high [SP value], or n-hexane, n-heptane, etc. with low [SP value]. Is preferred. Of course, if the difference in [SP value] is large, wetting with respect to the toner base particles (resin fine particles) becomes poor, and good dispersion of the toner base particles (resin fine particles) cannot be obtained. ~ 5 is preferred.
Moreover, 0.1-10 mass% is preferable and, as for content of the entrainer in the mixed fluid of at least any one of the said supercritical fluid and a subcritical fluid, and an entrainer, 0.5-5 mass% is more preferable. When the content is less than 0.1% by mass, it may be difficult to obtain the effect as an entrainer. When the content exceeds 10% by mass, the properties of the entrainer as a liquid become too strong, and supercritical or May make it difficult to obtain a subcritical state.

In the resin coating layer forming step in the coating layer forming process, the toner functional substance is a resin, and the resin coating layer is formed by contacting at least one of a supercritical fluid and a subcritical fluid, toner base particles, and a resin. It is a process to do.
There is no restriction | limiting in particular as coating resin for forming the said resin coating layer, According to the objective, it can select suitably, For example, polymethylmethacrylate resin, polystyrene, poly-alpha-methylstyrene, styrene-chlorostyrene Copolymer, Styrene-propylene copolymer, Styrene-butadiene copolymer, Styrene-vinyl chloride copolymer, Styrene-vinyl acetate copolymer, Styrene-maleic acid copolymer, Styrene-acrylic acid ester copolymer Styrene resins such as styrene-methacrylic acid ester copolymer, styrene-α-chloroacrylic acid methyl copolymer, styrene-acrylonitrile-acrylic acid ester copolymer; polyester resin, polyol resin, epoxy resin, vinyl chloride resin Rosin-modified maleic resin, phenolic resin, Examples thereof include reethylene resin, polypropylene resin, polyurethane resin, ketone resin, ethylene-ethyl acrylate copolymer, xylene resin, and polyvinyl butyrate resin. These may be used individually by 1 type and may use 2 or more types together.
The amount of the coating resin added is not particularly limited and may be appropriately selected depending on the intended purpose. It is preferably 1 to 300 parts by weight, more preferably 10 to 200 parts by weight, based on 100 parts by weight of the toner base particles. .

  In the coating layer forming step, the toner functional substance is a charge control agent, and at least one of a supercritical fluid and a subcritical fluid, toner base particles, and the charge control agent are brought into contact with each other. And forming a charge control agent coating layer.

  The charge control agent is not particularly limited and may be appropriately selected from known ones according to the purpose. However, since a color tone may change when a colored material is used, a colorless or nearly white material may be used. Preferably, for example, nigrosine dye, triphenylmethane dye, chromium-containing metal complex dye, molybdate chelate pigment, rhodamine dye, alkoxy amine, quaternary ammonium salt (including fluorine-modified quaternary ammonium salt), alkylamide And a simple substance of phosphorus or a compound thereof, a simple substance of tungsten or a compound thereof, a fluorine-based activator, a metal salt of salicylic acid, a metal salt of a salicylic acid derivative, and the like. Among these, salicylic acid metal salts and metal salts of salicylic acid derivatives are preferred. These may be used individually by 1 type and may use 2 or more types together. There is no restriction | limiting in particular as said metal, According to the objective, it can select suitably, For example, aluminum, zinc, titanium, strontium, boron, silicon, nickel, iron, chromium, zirconium etc. are mentioned.

  Commercially available products may be used as the charge control agent. Examples of the commercially available products include quaternary ammonium salt Bontron P-51, oxynaphthoic acid metal complex E-82, and salicylic acid metal complex. E-84, phenolic condensate E-89 (above, manufactured by Orient Chemical Co., Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, manufactured by Hodogaya Chemical Co., Ltd.), fourth Copy charge PSY VP2038 of quaternary ammonium salt, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR which is a boron complex -147 (Nippon Carlit), quinacridone, azo pigment, other sulfonic acid groups, cal Examples thereof include polymer compounds having a functional group such as a boxyl group and a quaternary ammonium salt.

  The addition amount of the charge control agent is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.5 to 5 parts by mass, and 1 to 3 parts by mass with respect to 100 parts by mass of the toner base particles. Is more preferable. When the addition amount is less than 0.5 parts by mass, the charging characteristics of the toner may be deteriorated. When the addition amount exceeds 5 parts by mass, the chargeability of the toner becomes too large, and the effect of the main charge control agent is increased. , And the electrostatic attraction force with the developing roller increases, which may lead to a decrease in developer fluidity and a decrease in image density.

  In the covering layer forming step, the releasing agent covering layer forming step is such that the toner functional substance is a releasing agent, and at least one of the supercritical fluid and the subcritical fluid, the toner base particles, and the releasing agent are brought into contact with each other. This is a step of forming a release agent coating layer.

There is no restriction | limiting in particular as said mold release agent, According to the objective, it can select suitably from well-known things, For example, waxes etc. are mentioned suitably.
Examples of the waxes include low molecular weight polyolefin waxes, synthetic hydrocarbon waxes, natural waxes, petroleum waxes, higher fatty acids and metal salts thereof, higher fatty acid amides, and various modified waxes thereof. These may be used individually by 1 type and may use 2 or more types together.
Examples of the low molecular weight polyolefin wax include low molecular weight polyethylene wax and low molecular weight polypropylene wax.
Examples of the synthetic hydrocarbon wax include Fischer-Tropsch wax.
Examples of the natural waxes include beeswax, carnauba wax, candelilla wax, rice wax, and montan wax.
Examples of the petroleum waxes include paraffin wax and microcrystalline wax.
Examples of the higher fatty acid include stearic acid, palmitic acid, myristic acid, and the like.

There is no restriction | limiting in particular as melting | fusing point of the said mold release agent, Although it can select suitably according to the objective, 40-160 degreeC is preferable, 50-120 degreeC is more preferable, 60-90 degreeC is especially preferable.
If the melting point is less than 40 ° C., the wax may adversely affect the heat-resistant storage stability. If the melting point exceeds 160 ° C., it may easily cause a cold offset when fixing at a low temperature. May occur.

  The addition amount of the release agent is not particularly limited and may be appropriately selected depending on the intended purpose. It is preferably 1 to 20 parts by weight, more preferably 3 to 15 parts by weight with respect to 100 parts by weight of the toner base particles. preferable.

The fluidity improver, which is another toner functional substance, means a substance capable of surface treatment to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity. Examples include coupling agents, silylating agents, silane coupling agents having a fluoroalkyl group, organic titanate coupling agents, aluminum coupling agents, silicone oils, and modified silicone oils.
The cleaning improver is added to the toner base particles in order to remove the transferred developer remaining on the photoreceptor or the primary transfer medium. For example, a fatty acid metal salt such as zinc stearate, calcium stearate, stearic acid or the like. And polymer fine particles produced by soap-free emulsion polymerization such as polymethyl methacrylate fine particles and polystyrene fine particles. The polymer fine particles preferably have a relatively narrow particle size distribution, and those having a volume average particle size of 0.01 to 1 μm are suitable.

The colorant is not particularly limited and may be appropriately selected from known dyes and pigments according to the purpose. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Lead Red, Lead Red, Cadmium Red, Cad Muum Mercury Red, Antimon Zhu, Permanent Red 4R, PA Red, Faise Red, Parachlor Ortho Nitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Risor Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pogment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oh Lured, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), Indigo, Ultramarine Blue, Bitumen, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Oxidation Chrome, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Ash Examples include degreen lake, malachite green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, and lithobon.
These may be used individually by 1 type and may use 2 or more types together.

As the colorant, a dye is particularly preferably used because it can be dissolved by at least one of a supercritical fluid and a subcritical fluid.
There is no restriction | limiting in particular as said dye, According to the objective, it can select suitably, For example, C.I. I. SOLVENT YELLOW (6, 9, 17, 31, 35, 100, 102, 103, 105), C.I. I. SOLVENT ORANGE (2, 7, 13, 14, 66), C.I. I. SOLVENT RED (5, 16, 17, 18, 19, 22, 23, 143.145, 146, 149, 150, 151, 157, 158), C.I. I. SOLVENT VIOLET (31, 32, 33, 37), C.I. I. SOLVEN BLUE (22, 63, 78, 83-86, 191, 194, 195, 104), C.I. I. SOLVEN GREEN (24, 25), C.I. I. SOLVEN BROWN (3, 9) and the like.
Moreover, there is no restriction | limiting in particular as a commercially available dye, According to the objective, it can select suitably, For example, Hodogaya Chemical Co., Ltd. Aizen SOT dye Yellow-1,3,4, Orange-1,2,3, Scarlet -1, Red-1,2,3, Brown-2, Blue-1,2, Violet-1, Green-1,2,3, Black-1,4,6,8; Sudan dye Yellow manufactured by BASF -146, 150, Orange-220, Red-290, 380, 460, Blue-670; Dialresin Yellow-3G, F, H2G, HG, HC, HL, Orange-HS, G, Red-GG manufactured by Mitsubishi Kasei. , S, HS, A, K, H5B, Violet-D, Blue-J, G, N, K, P, H3G, 4G, Green-C, Bro n-A: Oil color YElow-3G, GG-S, # 105, Orange-PS, PR, # 201, Scarlet- # 308, Red-5B, Brown-GR, # 416, Green-, manufactured by Orient Chemical Co., Ltd. BG, # 502, Blue-BOS, IIN, Black-HBB, # 803, EB, EX; Sumiplast Blue GP, OR, Red FB, 3B, Yellow FL7G, GC manufactured by Sumitomo Chemical; Nippon Kayaku Co., Ltd. Kayalon Polyester Black EX-SF300, Kaya Set Red-B, Blue A-2R, and the like can be used.

  The addition amount of the colorant is not particularly limited and may be appropriately selected depending on the degree of coloration, but is preferably 1 to 50 parts by mass with respect to 100 parts by mass of the toner base particles.

  The coating layer is preferably formed on part or all of the surface of the toner base particles. In this case, a selective coating layer can be formed according to a desired position on the surface of the toner base particles.

The method for forming the coating layer is not particularly limited as long as at least one of the supercritical fluid and the subcritical fluid is brought into contact with the toner base particles, and can be appropriately selected according to the purpose.
Here, the apparatus used for forming the coating layer is not particularly limited and may be appropriately selected according to the purpose. For example, a pressure vessel for performing coating layer forming treatment on the toner base particles A device including a pressurizing pump for supplying the supercritical fluid is preferable. As a processing method using the apparatus, first, the toner base particles are charged in the pressure vessel, and the supercritical fluid is supplied into the pressure vessel by a pressure pump, and the supercritical fluid is supplied to the toner base particles. , The coating layer forming material (release agent, resin, charge control agent, etc.) is deposited on the surface of the toner base particles, and the supercritical fluid containing the charge control agent is discharged. When the supercritical fluid is returned to normal temperature and normal pressure, the supercritical fluid becomes a gas, so that removal of the solvent is unnecessary and waste water generated by cleaning the surface of the toner base particles that has been conventionally required. Is unnecessary, and the burden on the environment is reduced.

The temperature at which the coating layer is formed is not particularly limited as long as it is equal to or higher than the critical temperature of the supercritical fluid or subcritical fluid to be used, and can be appropriately selected according to the purpose. The upper limit is preferably not higher than the melting point of the substance forming the toner base particles, and more preferably a temperature at which aggregation such as adhesion between the toner base particles does not occur. The lower limit of the critical temperature is preferably a temperature at which the other fluid that can be added to the supercritical fluid can exist as a gas.
Specifically, the temperature at which the coating layer is formed is preferably 0 to 100 ° C, and more preferably 20 to 80 ° C. When the temperature exceeds 60 ° C., the toner base particles may be dissolved.

  The pressure for forming the coating layer is not particularly limited as long as it is equal to or higher than the critical pressure of the supercritical fluid or the subcritical fluid to be used, and can be appropriately selected according to the purpose. Is preferred.

Here, a method for forming a resin coating layer on the surface of the toner base particles using the coating layer forming apparatus will be described. In the coating layer forming apparatus shown in FIG. 1, a reaction vessel 9 having a volume of 1000 cm ³ was used. In FIG. 1, 2 is an entrainer tank, 4 is a pressure pump, 6 is a temperature sensor, 113 is an injection nozzle, and 114 is a pressure sensor.
Carbon dioxide (CO ₂ ) was used as a gas for the supercritical fluid. An olefin polymer having a cyclic structure as a coating layer forming material was charged into the reaction vessel 9, and resin fine particles as toner base particles were charged.

Next, carbon dioxide gas was supplied from the gas cylinder 1, pressurized by the pressurizing pump 3, and introduced into the reaction vessel 9 through the valve 7. At this time, the valve 5 is closed, and carbon dioxide gas is not introduced into the ejection container 112 side. Here, the pressure reducing valve 8 for discharging and ejecting remains closed, and the pressure in the reaction vessel 9 rises due to the introduction of high-pressure carbon dioxide. In addition, the temperature inside the reaction vessel 9 was adjusted to 320 K with the heater 117.
When the pressure in the reaction vessel 9 is 7.3 MPa or more, the reaction vessel 9 is in a supercritical state. Moreover, each valve | bulb 5 and 7 was adjusted, the pressure in reaction container 9 was set to 20 Mpa, and it set to the state in which the olefin polymer which has a cyclic structure in reaction container 9 was dissolved. In this state, the valves 5 and 7 were closed, the dissolved state in the reaction vessel 9 was maintained for 120 minutes, and the supercritical fluid was sufficiently diffused and circulated. Thereafter, the valve 6 was opened, the pressure in the reaction vessel was adjusted to 10 MPa, and maintained for 60 minutes. Thereafter, carbon dioxide gas was introduced again from the high-pressure pump side, and introduction of carbon dioxide was continued while maintaining the pressure in the reaction vessel at 10 MPa. At this time, the supercritical fluid carbon dioxide contained in the mixed solution and the olefin polymer having a cyclic structure dissolved in the supercritical carbon dioxide are recovered by a recovery mechanism (not shown) and further illustrated. No separation device separates the carbon dioxide and the olefin copolymer having a cyclic structure from each other and reuses them.

  By continuing the introduction of supercritical carbon dioxide, the dissolved olefin-based polymer having a cyclic structure in the reaction vessel 9 is all discharged out of the vessel, and the reaction vessel 9 has an olefin having a deposited cyclic structure. It becomes only the resin fine particle and supercritical carbon dioxide fluid which have a system copolymer in a coating layer. Thereafter, the valve is opened, the supercritical carbon dioxide fluid is vaporized, and resin fine particles having a dried olefin copolymer having a cyclic structure as a coating layer can be produced.

  Through the above steps, a coating layer is formed on the surface of the toner base particles using at least one of the supercritical fluid and the subcritical fluid. As a result, the toner of the present invention having excellent releasability, charging performance and surface properties can be obtained.

  The shape, size, etc. of the toner are not particularly limited and can be appropriately selected according to the purpose. The image density, the average circularity, the volume average particle size, the volume average particle are as follows. It is preferable to have a ratio of the diameter to the number average particle diameter (volume average particle diameter / number average particle diameter).

The image density is preferably 1.90 or more, more preferably 2.00 or more, and particularly preferably 2.10 or more, as measured by a spectrometer (X-Light, 938 Spectrodensitometer). preferable.
If the image density is less than 1.90, the image density may be low and high image quality may not be obtained.
The image density is, for example, imagio Neo 450 (manufactured by Ricoh Co., Ltd.), and the amount of developer attached to copy paper (TYPE6000 <70W>; manufactured by Ricoh Co., Ltd.) is 1.00 ± 0.05 mg / cm ^2. The solid roller image was formed at a fixing roller surface temperature of 160 ± 2 ° C., and the image density at any six locations in the solid image obtained was measured using a spectrometer (938 Spectrodensitometer, manufactured by X-Light). It can be measured by measuring and calculating the average value.

The average circularity is a value obtained by dividing the perimeter of an equivalent circle having the same projected shape as the toner shape by the perimeter of the actual particles, and is preferably 0.900 to 0.980, for example, 0.950 to 0 .975 is more preferred. Note that particles having an average circularity of less than 0.94 are preferably 15% or less.
If the average circularity is less than 0.900, satisfactory transferability and a high-quality image free from dust may not be obtained. If the average circularity exceeds 0.980, image formation employing blade cleaning or the like is employed. In the system, defective cleaning occurs on the photoconductor and the transfer belt, and in the case of image formation with a high image area ratio such as a photographic image, an untransferred image is formed due to defective paper feeding, etc. The accumulated toner may become a transfer residual toner on the photoconductor, resulting in background smearing of the image, or it may contaminate the charging roller for charging the photoconductor in contact with the original charging ability. It may become impossible to demonstrate.
The average circularity is measured by, for example, an optical detection band method in which a suspension containing toner is passed through an imaging unit detection band on a flat plate, and a particle image is optically detected and analyzed by a CCD camera. For example, it can be measured using a flow type particle image analyzer FPIA-2100 (manufactured by Toa Medical Electronics Co., Ltd.).

There is no restriction | limiting in particular as a volume average particle diameter of the said toner, Although it can select suitably according to the objective, For example, 3-8 micrometers is preferable.
When the volume average particle size is less than 3 μm, in the two-component developer, the toner may be fused to the surface of the carrier during a long period of stirring in the developing device, and the charging ability of the carrier may be reduced. In the developer, toner filming on the developing roller and toner fusion to a member such as a blade are likely to occur because the toner is thinned, and if it exceeds 8 μm, the resolution is high and the resolution is high. It becomes difficult to obtain an image having an image quality, and when the balance of the toner in the developer is performed, the variation in the particle diameter of the toner may increase.

The ratio of the volume average particle diameter to the number average particle diameter (volume average particle diameter / number average particle diameter) in the toner is preferably 1.00 to 1.25, more preferably 1.10 to 1.25.
When the ratio of the volume average particle diameter to the number average particle diameter (volume average particle diameter / number average particle diameter) exceeds 1.25, the two-component developer causes the surface of the carrier to be agitated for a long period of time in the developing device. The toner may be fused to reduce the charging ability of the carrier. In the case of a one-component developer, the toner filming on the developing roller or the toner is thinned so that the toner is fused to a member such as a blade. May occur easily, and it becomes difficult to obtain a high-resolution and high-quality image, and when the balance of the toner in the developer is performed, the fluctuation of the toner particle size may increase. is there.

  The volume average particle size and the ratio of the volume average particle size to the number average particle size (volume average particle size / number average particle size) are, for example, a particle size measuring device “Coulter Counter TAII” manufactured by Coulter Electronics. Can be measured.

  In the toner manufacturing method of the present invention, in the coating layer forming step, the coating layer is formed on the surface of the toner base particles using at least one of the supercritical fluid and the subcritical fluid. Then, the coating layer made of a coating layer forming material such as a release agent, a resin, or a charge control agent is formed on at least the surface of the toner base particles. As a result, the toner of the present invention, which is excellent in releasability, charging performance, surface properties, and the like, can be manufactured with high efficiency without causing a load on the environment.

(Developer)
The developer of the present invention contains at least the toner of the present invention and other components appropriately selected such as a carrier. The developer may be a one-component developer or a two-component developer. However, when it is used for a high-speed printer or the like corresponding to the recent improvement in information processing speed, the life is improved. In view of the above, the two-component developer is preferable.
In the case of the one-component developer using the toner of the present invention, even if the balance of the toner is performed, there is little fluctuation in the particle diameter of the toner, and the filming of the toner on the developing roller or the toner is made thin. Therefore, the toner is not fused to a member such as a blade, and good and stable developability and image can be obtained even when the developing device is used (stirred) for a long time. In addition, in the case of the two-component developer using the toner of the present invention, even if the toner balance for a long time is performed, the fluctuation of the toner diameter in the developer is small, and it is good even for long-term stirring in the developing device. And stable developability can be obtained.

-Career-
There is no restriction | limiting in particular as said carrier, Although it can select suitably according to the objective, What has a core material and the resin layer which coat | covers this core material is preferable.

  There is no restriction | limiting in particular as a material of the said core material, It can select suitably from well-known things, For example, 50-90 emu / g manganese-strontium (Mn-Sr) type material, manganese-magnesium (Mn-) Mg) -based materials and the like are preferable, and highly magnetized materials such as iron powder (100 emu / g or more) and magnetite (75 to 120 emu / g) are preferable in terms of securing image density. In addition, a weakly magnetized material such as a copper-zinc (Cu—Zn) -based (30 to 80 emu / g) is advantageous in that it can weaken the contact with the photoconductor in which the toner is in a spiked state and is advantageous in improving the image quality. Is preferred. These may be used alone or in combination of two or more.

The core material has a volume average particle size of preferably 10 to 150 μm, and more preferably 40 to 100 μm.
When the average particle diameter (volume average particle diameter (D ₅₀ )) is less than 10 μm, the distribution of carrier particles may increase the number of fine powders, lower the magnetization per particle, and cause carrier scattering. If the thickness exceeds 150 μm, the specific surface area may decrease and toner scattering may occur. In the case of a full color having a large solid portion, the reproduction of the solid portion may be deteriorated.

  The material of the resin layer is not particularly limited and can be appropriately selected from known resins according to the purpose. For example, amino resins, polyvinyl resins, polystyrene resins, halogenated olefin resins, Polyester resin, polycarbonate resin, polyethylene resin, polyvinyl fluoride resin, polyvinylidene fluoride resin, polytrifluoroethylene resin, polyhexafluoropropylene resin, copolymer of vinylidene fluoride and acrylic monomer, vinylidene fluoride And a copolymer of vinyl fluoride, a fluoroterpolymer such as a terpolymer of tetrafluoroethylene, vinylidene fluoride, and a non-fluorinated monomer, and a silicone resin. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the amino resin include urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin. Examples of the polyvinyl resin include acrylic resin, polymethyl methacrylate resin, poly Examples include acrylonitrile resin, polyvinyl acetate resin, polyvinyl alcohol resin, and polyvinyl butyral resin. Examples of the polystyrene resin include polystyrene resin and styrene acrylic copolymer resin. Examples of the halogenated olefin resin include polyvinyl chloride. Examples of the polyester resin include polyethylene terephthalate resin and polybutylene terephthalate resin.

  The resin layer may contain conductive powder or the like as necessary. Examples of the conductive powder include metal powder, carbon black, titanium oxide, tin oxide, and zinc oxide. The average particle size of these conductive powders is preferably 1 μm or less. When the average particle diameter exceeds 1 μm, it may be difficult to control electric resistance.

For example, the resin layer is prepared by dissolving the silicone resin or the like in a solvent to prepare a coating solution, and then uniformly coating the coating solution on the surface of the core material by a known coating method, drying, and baking. It can be formed by doing. Examples of the application method include an immersion method, a spray method, and a brush coating method.
There is no restriction | limiting in particular as said solvent, Although it can select suitably according to the objective, For example, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cersol butyl acetate, etc. are mentioned.
The baking is not particularly limited, and may be an external heating method or an internal heating method. For example, a stationary electric furnace, a fluid electric furnace, a rotary electric furnace, a burner furnace, etc. The method of using, the method of using a microwave, etc. are mentioned.

The amount of the resin layer in the carrier is preferably 0.01 to 5.0% by mass.
When the amount is less than 0.01% by mass, the uniform resin layer may not be formed on the surface of the core material. When the amount exceeds 5.0% by mass, the resin layer becomes thick. In some cases, granulation of carriers occurs, and uniform carrier particles may not be obtained.

  When the developer is the two-component developer, the content of the carrier in the two-component developer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, 90 to 98% by mass Is preferable, and 93-97 mass% is more preferable.

Since the developer of the present invention contains the toner, it is excellent in charging performance and can stably form a high-quality image during image formation.
The developer of the present invention can be suitably used for image formation by various known electrophotographic methods such as a magnetic one-component development method, a non-magnetic one-component development method, and a two-component development method. It can be particularly suitably used for containers, process cartridges, image forming apparatuses and image forming methods.

(Toner container)
The toner-containing container of the present invention comprises the toner or the developer of the present invention contained in a container.
There is no restriction | limiting in particular as said container, It can select suitably from well-known things, For example, what has a container main body and a cap containing a toner etc. are mentioned suitably.
The size, shape, structure, material and the like of the container body containing toner are not particularly limited and can be appropriately selected according to the purpose. For example, the shape is preferably cylindrical. A spiral irregularity is formed on the peripheral surface, and the toner as the contents can be transferred to the discharge port side by rotating, and part or all of the spiral part has a bellows function, etc. Is particularly preferred.
The material of the toner-containing container body is not particularly limited, and those having good dimensional accuracy are preferable. For example, a resin is preferably used. Among them, for example, polyester resin, polyethylene resin, polypropylene resin, polystyrene resin, Preferable examples include vinyl chloride resin, polyacrylic acid, polycarbonate resin, ABS resin, polyacetal resin, and the like.
The toner-containing container of the present invention is easy to store and transport, has excellent handleability, and is preferably used for replenishing toner by being detachably attached to the process cartridge and image forming apparatus of the present invention described later. Can do.

(Process cartridge)
The process cartridge of the present invention develops an electrostatic latent image carrier carrying an electrostatic latent image and the electrostatic latent image carried on the electrostatic latent image carrier using a developer to form a visible image. And at least developing means for forming the film, and other means appropriately selected as necessary.
The developing means includes a developer container that contains the toner or developer of the present invention, and a developer carrier that carries and transports the toner or developer contained in the developer container. And a layer thickness regulating member for regulating the thickness of the toner layer to be carried.

Here, for example, as shown in FIG. 2, the process cartridge includes a photosensitive member 101, and includes a charging unit 102, an exposure unit 103, a developing unit 104, and a cleaning unit 107, and other members as necessary. It has.
As the photoreceptor 101, the same one as an image forming apparatus described later can be used.
An arbitrary charging member is used as the charging unit 102.
As the exposure means 103, a light source capable of writing with high resolution is used.
The process cartridge of the present invention can be detachably provided in various electrophotographic apparatuses, and is preferably detachably provided in the electrophotographic apparatus of the present invention described later.

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

The electrostatic latent image forming step is a step of forming an electrostatic latent image on the electrostatic latent image carrier.
There are no particular restrictions on the material, shape, structure, size, etc. of the electrostatic latent image bearing member (sometimes referred to as “photoconductive insulator” or “photosensitive member”), and among the known ones The shape is preferably a drum shape, and examples of the material include inorganic photoconductors such as amorphous silicon and selenium, and organic photoconductors such as polysilane and phthalopolymethine. It is done. Among these, amorphous silicon or the like is preferable in terms of long life.

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

The charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using the charger.
The charger is not particularly limited and may be appropriately selected depending on the purpose. And non-contact chargers utilizing corona discharge such as corotrons and corotrons.

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

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

  The developing unit may be a dry developing type, a wet developing type, a single color developing unit, or a multi-color developing unit. For example, a toner having a stirrer for charging the toner or the developer by frictional stirring and a rotatable magnet roller is preferable.

  In the developing device, for example, the toner and the carrier are mixed and agitated, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state to form a magnetic brush. . Since the magnet roller is disposed in the vicinity of the electrostatic latent image carrier (photoconductor), a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is electrically attracted. It moves to the surface of the electrostatic latent image carrier (photoconductor) by force. As a result, the electrostatic latent image is developed with the toner, and a visible image is formed with the toner on the surface of the electrostatic latent image carrier (photoconductor).

  The developer accommodated in the developing device is a developer containing the toner of the present invention, but the developer may be a one-component developer or a two-component developer. The toner contained in the developer is the toner of the present invention.

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

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

The fixing step is a step of fixing the visible image transferred to the recording medium using a fixing device, and may be performed each time the toner of each color is transferred to the recording medium, or for the toner of each color. You may perform this simultaneously in the state which laminated | stacked this.
There is no restriction | limiting in particular as said fixing device, Although it can select suitably according to the objective, A well-known heating-pressing means is suitable. Examples of the heating and pressing means include a combination of a heating roller and a pressure roller, a combination of a heating roller, a pressure roller, and an endless belt.
The heating in the heating and pressurizing means is usually preferably 80 ° C to 200 ° C.
In the present invention, for example, a known optical fixing device may be used together with or in place of the fixing step and the fixing unit depending on the purpose.

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

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

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

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

  One mode for carrying out the image forming method of the present invention by the image forming apparatus of the present invention will be described with reference to FIG. An image forming apparatus 100 shown in FIG. 3 includes a photosensitive drum 10 (hereinafter referred to as “photosensitive member 10”) as the electrostatic latent image carrier, a charging roller 20 as the charging unit, and an exposure as the exposure unit. The apparatus 30 includes a developing device 40 as the developing means, an intermediate transfer member 50, a cleaning device 60 as the cleaning means having a cleaning blade, and a static elimination lamp 70 as the static elimination means.

  The intermediate transfer member 50 is an endless belt, and is designed to be movable in the direction of an arrow by three rollers 51 that are arranged inside and stretched. Part of the three rollers 51 also functions as a transfer bias roller that can apply a predetermined transfer bias (primary transfer bias) to the intermediate transfer member 50. The intermediate transfer body 50 is provided with a cleaning device 90 having a cleaning blade in the vicinity thereof, and for transferring (secondary transfer) a developed image (toner image) to a transfer sheet 95 as a final transfer material. A transfer roller 80 serving as a transfer unit to which a transfer bias can be applied is disposed to face the transfer roller 80. Around the intermediate transfer member 50, a corona charger 58 for applying a charge to the toner image on the intermediate transfer member 50 is arranged between the photosensitive member 10 and the intermediate transfer member 50 in the rotation direction of the intermediate transfer member 50. It is disposed between the contact portion and the contact portion between the intermediate transfer member 50 and the transfer paper 95.

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

  In the image forming apparatus 100 shown in FIG. 3, for example, the charging roller 20 uniformly charges the photosensitive drum 10. The exposure device 30 performs imagewise exposure on the photosensitive drum 10 to form an electrostatic latent image. The electrostatic latent image formed on the photosensitive drum 10 is developed by supplying toner from the developing device 40 to form a visible image (toner image). The visible image (toner image) is transferred (primary transfer) onto the intermediate transfer member 50 by the voltage applied from the roller 51, and further transferred (secondary transfer) onto the transfer paper 95. As a result, a transfer image is formed on the transfer paper 95. The residual toner on the photoconductor 10 is removed by the cleaning device 60, and the charge on the photoconductor 10 is temporarily removed by the charge eliminating lamp 70.

  Another mode for carrying out the image forming method of the present invention by the image forming apparatus of the present invention will be described with reference to FIG. The image forming apparatus 100 shown in FIG. 4 does not include the developing belt 41 in the image forming apparatus 100 shown in FIG. 3, and a black developing unit 45K, a yellow developing unit 45Y, a magenta developing unit 45M, and the like around the photoconductor 10. Except for the fact that the cyan developing unit 45C is arranged directly opposite, it has the same configuration as the image forming apparatus 100 shown in FIG. In FIG. 4, the same components as those in FIG. 3 are denoted by the same reference numerals.

Another mode for carrying out the image forming method of the present invention by the image forming apparatus of the present invention will be described with reference to FIG. A tandem image forming apparatus 120 shown in FIG. 5 is a tandem color image forming apparatus. The tandem image forming apparatus 120 includes a copying apparatus main body 150, a paper feed table 200, a scanner 300, and an automatic document feeder (ADF) 400.
The copying apparatus main body 150 is provided with an endless belt-like intermediate transfer member 50 at the center. The intermediate transfer member 50 is stretched around the support rollers 14, 15, and 16 and can be rotated clockwise in FIG. 5. An intermediate transfer member cleaning device 17 for removing residual toner on the intermediate transfer member 50 is disposed in the vicinity of the support roller 15. The intermediate transfer member 50 stretched between the support roller 14 and the support roller 15 is a tandem type in which four image forming units 18 of yellow, cyan, magenta, and black are arranged to face each other along the conveyance direction. A developing device 120 is disposed. An exposure device 21 is disposed in the vicinity of the tandem developing device 120. A secondary transfer device 22 is disposed on the side of the intermediate transfer member 50 opposite to the side on which the tandem developing device 120 is disposed. In the secondary transfer device 22, a secondary transfer belt 24, which is an endless belt, is stretched around a pair of rollers 23, and the transfer paper conveyed on the secondary transfer belt 24 and the intermediate transfer body 50 are in contact with each other. Is possible. A fixing device 25 is disposed in the vicinity of the secondary transfer device 22. The fixing device 25 includes a fixing belt 26 that is an endless belt, and a pressure roller 27 that is pressed against the fixing belt 26.
In the tandem image forming apparatus 120, a sheet reversing device 28 for reversing the transfer paper for image formation on both sides of the transfer paper is disposed in the vicinity of the secondary transfer device 22 and the fixing device 25. Yes.

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

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

  Each image information of black, yellow, magenta and cyan is stored in each image forming means 18 (black image forming means, yellow image forming means, magenta image forming means and cyan image forming means in the tandem developing device 120. ) And black, yellow, magenta and cyan toner images are formed in the respective image forming means. That is, each image forming means 18 (black image forming means, yellow image forming means, magenta image forming means, and cyan image forming means) in the tandem type developing device 120 is photosensitive as shown in FIG. On the basis of the body 10 (the black photoreceptor 10K, the yellow photoreceptor 10Y, the magenta photoreceptor 10M, and the cyan photoreceptor 10C), the charger 60 that uniformly charges the photoreceptor, and each color image information. The photosensitive member is exposed to each color image corresponding image (L in FIG. 6), and an electrostatic latent image corresponding to each color image is formed on the photosensitive member. A developing device 61 that develops using color toner (black toner, yellow toner, magenta toner, and cyan toner) to form a toner image of each color toner, and the toner image is transferred to the intermediate transfer member 5. The image forming apparatus includes a transfer charger 62 for transferring the image on the surface, a photoconductor cleaning device 63, and a static eliminator 64, and each monochrome image (black image, yellow image, magenta image) based on image information of each color. And cyan images) can be formed. The black image, the yellow image, the magenta image, and the cyan image formed in this way are formed on the black photoconductor 10K on the intermediate transfer member 50 that is rotationally moved by the support rollers 14, 15, and 16, respectively. The black image, the yellow image formed on the yellow photoconductor 10Y, the magenta image formed on the magenta photoconductor 10M, and the cyan image formed on the cyan photoconductor 10C are sequentially transferred (primary transfer). Is done. Then, the black image, the yellow image, the magenta image, and the cyan image are superimposed on the intermediate transfer member 50 to form a composite color image (color transfer image).

On the other hand, in the paper feed table 200, one of the paper feed rollers 142 is selectively rotated to feed out a sheet (recording paper) from one of the paper feed cassettes 144 provided in multiple stages in the paper bank 143. Each sheet is separated and sent to the paper feed path 146, transported by the transport roller 147, guided to the paper feed path 148 in the copying machine main body 150, and abutted against the registration roller 49 and stopped. Alternatively, the sheet feeding roller 150 is rotated to feed out sheets (recording paper) on the manual feed tray 51, separated one by one by the separation roller 52, put into the manual feed path 53, and abutted against the registration roller 49 and stopped. . The registration roller 49 is generally used while being grounded, but may be used in a state where a bias is applied to remove paper dust from the sheet.
Then, the registration roller 49 is rotated in synchronization with the synthesized color image (color transfer image) synthesized on the intermediate transfer member 50, and a sheet (recording paper) is interposed between the intermediate transfer member 50 and the secondary transfer device 22. And transferring the composite color image (color transfer image) onto the sheet (recording paper) by the secondary transfer device 22, thereby transferring the color image onto the sheet (recording paper). Is formed. The residual toner on the intermediate transfer member 50 after image transfer is cleaned by the intermediate transfer member cleaning device 17.

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

  In the image forming apparatus and the image forming method of the present invention, since the toner of the present invention excellent in releasability, charging performance, surface properties, and the like is used, a high-quality image can be obtained efficiently.

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

Example 1
<Preparation of toner base particles 1>
-Preparation of polymerizable monomer for core-
Polymeric monomer for core consisting of 80 parts by mass of styrene and 20 parts by mass of n-butyl acrylate (the glass transition temperature (Tg) of the resulting copolymer = 55 ° C. (calculated value)) and carbon black (Mitsubishi Chemical) 7 parts by mass, product name: # 25B), 1 part by mass of charge control agent (trade name: Spiron Black TRH, manufactured by Hodogaya Chemical Co., Ltd.), 0.3 part by mass of divinylbenzene, and 0 tert-decyl mercaptan 0.8 parts by mass, 10 parts by mass of pentaerythritol tetrastearate (stearic acid: purity of about 60%), and natural gas Fischer-Tropsch wax (D Shell MMS, trade name: FT-100, melting point 92 ° C.) 2 parts by mass are stirred and mixed at a rotational speed of 11000 rpm with a homomixer (Special Machine Chemical Co., Ltd., TK type) that can be mixed with a high shear force. Was carried out, the core polymerizable monomer for composition (mixture) was prepared.

-Preparation of polymerizable monomer for shell-
5 parts by weight of methyl methacrylate (glass transition temperature (Tg) = 105 ° C. (calculated value)) and 100 parts by weight of water are finely dispersed using an ultrasonic emulsifier (TK homomixer manufactured by Tokushu Kika Co., Ltd.). The aqueous dispersion of the polymerizable monomer for shells was prepared.

-Preparation of magnesium hydroxide colloid dispersion-
In an aqueous solution obtained by dissolving 9.8 parts by mass of magnesium chloride (water-soluble polyvalent metal salt) in 250 parts by mass of ion-exchanged water, sodium hydroxide (alkali metal hydroxide) is added to 50 parts by mass of ion-exchanged water. An aqueous solution obtained by dissolving 9 parts by mass was gradually added with stirring to prepare a magnesium hydroxide colloid (colloid of a hardly water-soluble metal compound) dispersion.

To the obtained magnesium hydroxide colloid dispersion, the core polymerizable monomer composition was added and mixed, and then 4 parts by mass of tert-butyl peroxy 2-ethylhexanoate was added, and a TK homomixer was used. High shear stirring was performed at a rotational speed of 11000 rpm to granulate droplets of the polymerizable monomer composition for the core. The aqueous dispersion of the granulated monomer composition was placed in a polymerization reactor equipped with a stirring blade, the polymerization reaction was started at 90 ° C., and when the polymerization conversion reached almost 100%, An aqueous dispersion of a polymerizable monomer for shell and 1 part by mass of a 1% aqueous potassium persulfate solution were added, and the reaction was continued for 5 hours. Then, the reaction was stopped, and an aqueous dispersion of core / shell polymer particles. Was prepared.
While stirring the aqueous dispersion of the obtained core-shell type polymer particles, the system was acid-washed (25 ° C., 10 minutes) with sulfuric acid to a pH of 4 or less, and water was separated by filtration. 500 parts by mass of ion-exchanged water was added to form a slurry again and washed with water. Thereafter, again, dehydration and water washing were repeated several times, and the solid content was filtered and separated, followed by drying at 45 ° C. for a whole day and night to obtain toner base particles 1 (resin fine particles 1).

<Coating layer forming step>
10 g of the obtained toner base particles 1 (resin fine particles 1) and 1 g of a charge control agent (manufactured by Clariant Japan, Copy Charge PSY) as a material for forming a coating layer are filled in a processing cell, and ethanol (purity) is used as a cosolvent. (99.5% or more) 100 ml was added. Next, carbon dioxide is selected as a supercritical fluid, the carbon dioxide is supplied into the processing cell by a supply cylinder, the upper limit pressure is adjusted by a pressure valve, and the temperature controller controls it to 313.15 ± 0.5K. did. The protective tube was controlled at 350.15 ± 0.5K.
The processing system is kept closed (for example, all valves are closed), and carbon dioxide gas is sent to the processing cell (for example, a valve that sends carbon dioxide gas is opened and carbon dioxide gas is sent) . Subsequently, carbon dioxide gas was sent and pressurized until the system (in the treatment cell) reached the operating pressure. The inside of the treatment cell is stirred by a stirring motor, and the rotation speed of the stirring shaft is adjusted by a digital rotation indicator, and the flow rate is 5.0 L / min (standard state conversion value), 70 ° C., 40.52 MPa (400 atm), 5 The supercritical carbon dioxide was circulated under the time treatment conditions, and a coating layer made of the charge control agent was formed on the surface of the toner to produce toner 1. The coating layer was formed for 30 minutes.

After the preparation of the toner, carbon dioxide in which the charge control agent was dissolved in the processing cell was replaced with a supercritical carbon dioxide fluid containing no dissolved material, the pressure was returned to normal pressure, and the toner was taken out from the processing cell.
The toner thus obtained does not require a drying process or a washing process, and after the coating layer forming step, the reaction vessel containing the supercritical fluid is decompressed to remove carbon dioxide. Just care and the process is complete. For this reason, the toner can be produced efficiently in a very short time, and the waste liquid is not required to be treated, thereby reducing the burden on the environment.

(Comparative Example 1)
-Production of Comparative Toner 1-
In Example 1, Comparative toner 1 was produced in the same manner as Example 1 except that the coating layer forming step was not performed.

-Production of developer-
Next, 100 parts by mass of the obtained toner 1 and comparative toner 1 are each 0.8 parts by mass of silica having a volume-average particle diameter of 12 nm (trade name “NA50H” manufactured by Nippon Aerosil Co., Ltd.) subjected to a hydrophobic treatment. Part 1 was added and surface treatment was performed using a Henschel mixer to prepare developer 1 (positively charged) and comparative developer 2 (positively charged).

  Next, the obtained developers of Example 1 and Comparative Example 1 were subjected to image density, fusion to a photoreceptor, charge amount, and comprehensive evaluation as follows. The results are shown in Table 1.

<Image density>
About each developer of Example 1 and Comparative Example 1 obtained, a non-magnetic one-component development system laser printer (manufactured by Kyocera Mita, DP-560) was used to copy paper (TYPE6000 <70W>, manufactured by Ricoh Co., Ltd.). ) Was formed as a solid image having an adhesion amount of each developer of 1.00 ± 0.05 mg / cm ² . The solid image was repeatedly formed on 8000 copy sheets. The image density of the obtained solid image was visually observed for the initial stage and after the endurance of 8000 sheets, and evaluated based on the following criteria.
Note that the higher the image density obtained, the higher the density image can be formed. This evaluation corresponds to an embodiment of the toner container, the process cartridge, and the image forming method of the present invention.
〔Evaluation criteria〕
◯: There was no change in the image density at the initial stage and after the endurance of 8000 sheets, and high image quality was obtained
Δ: The image density was slightly lowered and the image quality was lowered after the endurance of 8000 sheets.
X: After the endurance of 8000 sheets, the image density was remarkably lowered and the image quality was greatly lowered.

<Fusion>
After the image formation, the adhesion of each developer to the photosensitive member was visually observed and evaluated based on the following criteria.
〔Evaluation criteria〕
○: No fusion of the developer to the photoreceptor was observed.
X: Fusion of the developer to the photoreceptor was observed.

<Charge amount>
6 g of each developer was weighed, charged into a metal cylinder that could be sealed, and blown to obtain the charge amount. The developer concentration was adjusted to 4.5 to 5.5% by mass.

<Comprehensive evaluation>
From the evaluation results of the above characteristics, a comprehensive judgment was made and the following criteria were used.
○: Good ×: Bad (unusable)

From the results shown in Table 1, Example 1 using toner containing toner base particles in which a charge control agent coating layer is formed by a supercritical fluid is superior in charging performance to the developer of Comparative Example 1, and has a high image density. It was confirmed that

  The toner manufacturing method of the present invention has a low environmental load. Further, the toner of the present invention produced by this method is excellent in releasability, charging performance, surface properties and the like, and therefore is suitably used for high quality image formation. The developer, toner-containing container, image forming method, and process cartridge of the present invention using the toner of the present invention are preferably used for high-quality image formation.

FIG. 1 is a schematic view showing an example of an apparatus used in the coating layer forming step of the present invention. FIG. 2 is a schematic explanatory view showing an example of the process cartridge of the present invention. FIG. 3 is a schematic explanatory view showing an example in which the image forming method of the present invention is carried out by the image forming apparatus of the present invention. FIG. 4 is a schematic explanatory view showing another example in which the image forming method of the present invention is implemented by the image forming apparatus of the present invention. FIG. 5 is a schematic explanatory view showing an example in which the image forming method of the present invention is implemented by the image forming apparatus (tandem color image forming apparatus) of the present invention. 6 is a partially enlarged schematic explanatory view of the image forming apparatus shown in FIG.

Explanation of symbols

1 Gas cylinder 3 Pressure pump 5, 7, 8 Valve 9 Reaction vessel 10 Photoconductor (photosensitive drum)
10K black photoconductor 10Y yellow photoconductor 10M magenta photoconductor 10C cyan photoconductor 14 support roller 15 support roller 16 support roller 17 intermediate transfer cleaning device 18 image forming means 20 charging roller 21 exposure device 22 secondary transfer device 23 Roller 24 Secondary transfer belt 25 Fixing device 26 Fixing belt 27 Pressure belt 28 Sheet reversing device 30 Exposure device 32 Contact glass 33 First traveling member 34 Second traveling member 35 Imaging lens 36 Reading sensor 40 Developing device 41 Developing belt 42K Developer container 42Y Developer container 42M Developer container 42C Developer container 43K Developer supply roller 43Y Developer supply roller 43M Developer supply roller 43C Developer supply roller 44K Developer roller 44Y Developer roller 44M Developer Roller 44C Developing roller 45K Black developing unit 45Y Yellow developing unit 45M Magenta developing unit 45C Cyan developing unit 49 Registration roller 50 Intermediate transfer member 51 Roller 52 Separating roller 53 Constant current source 55 Switching claw 56 Discharging roller 57 Discharging tray 58 Corona charger 60 Cleaning device 61 Developer 62 Transfer charger 63 Photoconductor cleaning device 64 Charger 70 Charger lamp 80 Transfer roller 90 Cleaning device 95 Transfer paper 100 Image forming device 101 Photoconductor 102 Charging means 103 Exposure 104 Developing means 105 Transfer Body 106 Transfer means 107 Cleaning means 120 Tandem developer 121 Heating roller 122 Fixing roller 123 Fixing belt 124 Pressure roller 125 Heating source 126 Cleaning roller 127 Temperature Sensor 130 platen 142 paper feed roller 143 paper bank 144 sheet cassette 145 separating roller 146 feed path 147 transport rollers 148 feed path 150 copier main body 200 feeder table 300 Scanner 400 automatic document feeder (ADF)

Claims (15)

  Using a toner base particle manufacturing process in which toner base particles containing at least resin fine particles are granulated in an aqueous medium, and at least one of a supercritical fluid and a subcritical fluid that do not dissolve the toner base particles A charge control agent coating layer forming step of forming a coating layer made of a charge control agent on the surface of the toner base particles.   The method for producing a toner according to claim 1, wherein at least one of the supercritical fluid and the subcritical fluid can dissolve the charge control agent without dissolving the toner base particles.   The method for producing a toner according to claim 1, wherein the charge control agent coating layer is formed by depositing a charge control agent dissolved in at least one of a supercritical fluid and a subcritical fluid. .   4. The toner manufacturing method according to claim 1, wherein the charge control agent coating layer is formed on a part or all of the surface of the toner base particles.   The method for producing a toner according to claim 1, wherein at least one of the supercritical fluid and the subcritical fluid is either a simple substance or a mixture.   The method for producing a toner according to claim 1, wherein at least one of the supercritical fluid and the subcritical fluid contains at least carbon dioxide.   The method for producing a toner according to claim 1, wherein at least one of the supercritical fluid and the subcritical fluid includes an entrainer.   The toner production method according to claim 7, wherein the content of the entrainer is 0.1 to 10% by mass.   The method for producing a toner according to claim 7, wherein the entrainer is a polar organic solvent.   A toner produced by the toner production method according to claim 1, wherein the volume average particle diameter is 0.900 to 0.980, and (volume average particle diameter / number average particle diameter). A toner having a toner viscosity of 1.00 to 1.25.   A developer comprising the toner according to claim 10.   A toner-filled container filled with the toner according to claim 10. A process cartridge comprising at least an electrostatic latent image carrier and developing means having at least a toner-containing container filled with the toner according to claim 10 . An electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, and developing the electrostatic latent image with toner to form a visible image A developing unit having at least a toner-filled container filled with the toner according to claim 10, a transfer unit that transfers the visible image to a recording medium, and a fixing that fixes the transferred image transferred to the recording medium And an image forming apparatus.   An electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier, and a developing step of developing the electrostatic latent image using the toner according to claim 10 to form a visible image. And an image forming method comprising: a transfer step of transferring the visible image onto a recording medium; and a fixing step of fixing the transfer image transferred onto the recording medium.