JP2002268277A - Method for manufacturing toner for electrophotography - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an efficient method for preparing toner for electrophotography by which fast charging in the case of being replenished or being placed on a developing sleeve and the small variation of charging property among toner grains are achieved, and the toner for electrophotography capable of representing a high-definition picture free from the deformation and excessive crash of the grains is obtained by a simple process and the large quantity of treating powder occupying a treating capacity is secured in a method for preparing toner which has appropriate electrification capacity by mixing charge control agent grains, coloring agent and resin. SOLUTION: In the method for preparing toner for electrophotography, an agitating blade is arranged at the bottom of a container tank, a cylindrical member is arranged on the extension line of the driving shaft of the agitating blade, matter to be treated discharged by the agitation blade is received by the inner wall surface of a cylindrical member to lower the motion energy of the matter to be treated, grains including coloring agent and resin and grains consisting of charging control agent grains or externally add-in agent are mix- treated by using a mixer having a mechanism for feeding the matter to be treated to the agitation blade at the bottom of the tank again.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a toner used as a developer for developing an electrostatic image in electrophotography, electrostatic recording, electrostatic printing, and the like. More specifically, a copier using a direct or indirect electrophotographic development system,
The present invention relates to a method for producing an electrophotographic toner used for a laser printer, a plain paper fax, and the like. Further, the present invention relates to a method for producing an electrophotographic toner used in a full-color copying machine, a full-color laser printer, a full-color plain paper fax, and the like using a direct or indirect electrophotographic multicolor image developing system.

[0002]

2. Description of the Related Art Developers used in electrophotography, electrostatic recording, electrostatic printing and the like are once adhered to an image carrier such as a photoconductor on which an electrostatic image is formed, in a developing process. Next, after being transferred from the photoreceptor to a transfer medium such as transfer paper in a transfer step, it is fixed on the paper surface in a fixing step. At that time, as a developer for developing the electrostatic image formed on the latent image holding surface, a two-component developer composed of a carrier and a toner and a one-component developer not requiring a carrier (magnetic toner, Non-magnetic toner) is known.

In the case of a two-component developer, the carrier comes into contact with the carrier, and in the case of a one-component developer, it comes into contact with a supply roller for supplying toner to the developing sleeve, and the toner layer is made uniform on the developing sleeve. The frictional charging is performed by contact with a layer thickness regulating blade or the like. In order to faithfully reproduce an electrostatic charge image on an image carrier such as a photoreceptor, the charging characteristics of the toner are important, and various types of charge control agents and methods for incorporating the toner into the toner have been studied.

[0004] In particular, charge control agents are often expensive and function on the surface of toner particles, so that attempts have been made to arrange them in small amounts on the surface of toner particles. For example, JP-A-63-10
4064, JP-A-05-119513, JP-A-09-127720, JP-A-11-3271
No. 99, etc., describes that a charge control agent is attached to the surface of toner particles to impart chargeability to the toner, but the chargeability is not sufficient, and the toner is easily detached from the surface. The production method also failed to provide the desired chargeability. In particular, no consideration was given to the initial charging speed of the toner.

Further, a charge control agent is attached and fixed to the surface of toner particles by using an impact force generated in a gap between a blade rotating at a high speed called a rotor and a projection piece fixed to a container wall of a stator called a stator. Manufacturing method,
It is described in JP-A-63-244056. However, there are projections on the inner wall, and if it is not smooth, turbulence is likely to occur in the high-speed airflow, and excessive pulverization of the particles, local melting of the particle surface, burying of the charge control agent on the surface, and processing of the powder are not possible. It is easy to be uniform. This is considered to be due to the variation in energy given between the particles. That is, when processing is performed through such a narrow gap, a large amount of heat is generated due to the impact force in the airflow, and the toner particles are deformed or the toner particles are crushed, and the average particle size and the particle size are increased. There is a problem that the distribution is out of the desired one.
Further, when the charge control agent is buried inside the particle surface, the performance may not be sufficiently exhibited. Further, with respect to the actual manufacturability, the amount of the powder to be processed is extremely small compared to the processing space due to the heat generation and excessive pulverization, and is not suitable for efficient production.

Japanese Patent Application Laid-Open No. 08-173783 discloses that a processing tank is made spherical, and a tank bottom is formed in a horizontal disk shape, and a drive shaft vertically penetrating the center of the tank bottom has a conical or similar shape. A mixer is described in which a boss is attached, and a stirring blade that discharges the object along the inner wall of the processing tank is provided on the outer periphery of the lower end of the boss. When approaching the peripheral speed of the stirring blade, the shear energy applied to the object to be treated is reduced, and the object to be treated is converted into primary particles, which makes it impossible to uniformly disperse and mix the material, resulting in a so-called “rotary” state. There is a problem that.

Further, the mixer has a function of generating an upward swirling airflow along the inner wall of the processing tank and circulating the object to be processed, but has no function of returning the airflow downward. As a result, the object discharged upward does not return to the stirring blade, and self-cleaning by the object is not performed, so that there is a problem that the object accumulates on the inner wall of the processing tank.

Further, when mixing particles containing a colorant and a resin with particles of a charge control agent or a fluidization-imparting agent by means of a mixer, the shaft of the rotating body is heated to a high temperature. There is a method of preventing solidification due to clogging. For this reason, a mechanism for discharging the supplied air to the outside is required. As a mechanism for discharging the air to the outside, a method of discharging the air from a mechanism as shown in the upper inlet in a representative diagram of Japanese Patent Application Laid-Open No. 08-173783 is used. It is common to arrange a filter in this part and discharge air to the outside.

If the filter does not have a sufficient area, clogging occurs, air supply to the rotating body is not performed smoothly, and the object to be processed is solidified on the shaft of the rotating body. In many cases, the structure protrudes greatly upward. However, the object to be treated adheres to this filter due to the effect of turbulence acting outward from the air discharge port along the inner wall of the processing tank along the spherical tank wall by the stirring blade. In addition, since a part of the processing object does not circulate, uniform processing is not performed, and the rise of the charge amount of the processed toner is poor, which is a practical problem. Also,
There is also a problem that an object to be processed is deposited in the container because the adhesion proceeds.

[0010]

SUMMARY OF THE INVENTION The present invention is a method for giving a proper charging ability to a toner by mixing a charge control agent particle, a colorant and a resin-containing particle, and solves the above-mentioned problems. Because of this, the charging speed is high when toner is supplied or placed on the developing sleeve, the chargeability between toner particles is small, and high quality images without particle deformation and over-crushing can be expressed. It is an object of the present invention to provide a method for producing a toner for use in a computer. It is an object of the present invention to provide an efficient method for producing an electrophotographic toner in a simpler process and with a large amount of processing powder in the processing volume.

[0011]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a particle containing a colorant and a resin and a particle comprising a charge control agent particle or an external additive are mixed in an electrophotographic container. In the method for producing a toner, a stirring blade is arranged at the bottom of the container tank, a cylindrical member is arranged on an extension of a drive shaft of the stirring blade, and a processing target discharged by the stirring blade is disposed.
The particles containing the colorant and the resin are charged by using a mixer having a mechanism for reducing the kinetic energy of the object to be treated by receiving it on the inner wall surface of the cylindrical member and re-supplying the object to the stirring blade at the bottom of the tank. By mixing and controlling the particles of the control agent or the particles of the external additive, the problems of the above-mentioned "rotating around", "turbulence of the air flow", and "accumulation of the object to be treated on the inner wall" have been solved ( (See FIG. 2).

In particular, the processing tank has a spherical shape, the tank bottom has a horizontal disk shape, and a stirring blade having a drive shaft vertically penetrating the center of the tank bottom is disposed at the tank bottom. Having a stirring blade that discharges the object to be processed upward along, and
A cylindrical member is arranged inside the container on the extension of the drive shaft of the stirring blade, and the object to be processed released by the stirring blade is received by the inner wall surface of the cylindrical member to reduce the kinetic energy of the object to be processed. By using a mixer having a mechanism for re-supplying the processing object to the stirring blades at the bottom of the tank, the particles containing the colorant and the resin and the particles comprising the charge control agent particles or the external additive are mixed with each other, whereby the charged particles are charged. The control agent and the external additive can be uniformly and firmly fixed to the base particles, and the durability is remarkably improved (see FIG. 3).

Therefore, in the manufacturing method of the present invention, the stirring blade rotates to bring the particles to be processed into contact with the inner wall of the apparatus from a parabolic direction, whereby the object to be processed is placed in a non-vertical direction on the inner wall of the apparatus. Contact to reduce severe collisions. If the inner wall surface of the device is curved, its function can be sufficiently exhibited.

If the cross section of the cylindrical member is not a circle but a polygon, the function is exhibited.
By using a cylindrical tube having a perfect circular cross section, the swirling airflow flows more smoothly, and more uniform processing is possible.

Since the center of the container has a relatively low air pressure, the shaft sealing air is discharged from the center of the container to the outside of the container through the cylindrical member, thereby rotating the stirring blade at high speed. However, since the object to be processed hardly enters the discharge portion (the cylindrical member) of the shaft seal air, more uniform processing is possible.

In order for the cylindrical member to exhibit the effect, when the height inside the container is H and the length of the cylindrical member is L, it is necessary that 1/10 · H ≦ L. There is. In order to prevent "rotation around", a length of 1 / 3H or more is required. If the length of the cylindrical member is shorter than 1 / 10H, the object to be processed enters the inside of the cylindrical member, making uniform processing difficult (see FIG. 4).

The inner diameter R2 of the cylindrical member must have a diameter equal to or greater than 1/10 of the inner diameter R1 of the container. 1/10
In the following, since it does not have a sufficient area, the kinetic energy of the object to be processed is reduced, the function is low, and "together" tends to occur (see FIG. 4).

By making the tip of the tubular member trumpet-shaped, it is possible to further prevent the workpiece from entering the inside of the tubular member (see FIG. 4B).

Since the base portion of the cylindrical member has a rounded portion, the object to be processed circulates smoothly, and the accumulation can be prevented (see the portion (a) of FIG. 4).

The mixing machine shown in FIG. 3 having the structure of claim 2 is capable of uniformly mixing at a high speed of 50 to 150 m / sec, and firmly fixes the charge control agent on the surface of the toner particles. Can be realized.

The particles containing the colorant and the resin and the particles of the charge control agent are preliminarily mixed at a peripheral speed of the rotating body of 50 m / sec or less for a predetermined time, and then mixed at a peripheral speed of the rotating body of 50 m / sec or more. Uniform processing becomes possible, and the rise of the charge amount is further improved. Further, by setting the weight average particle size of the charge control agent to 3 μm or less, more uniform processing becomes possible, and the rise of the charge amount is further improved.

Hereinafter, the present invention will be described in detail.
The present invention is of course not limited to these. The particles containing the colorant and the resin in the present invention are made of, for example, the following constituent materials. As the binder resin, styrene such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene and a polymer of a substituted product thereof;
Styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-
Methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer Coalesce, styrene-butyl methacrylate copolymer,
Styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer Styrene-based copolymers such as styrene-maleic acid copolymer, styrene-maleic acid ester copolymer; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester,
Epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax, etc. And these can be used alone or in combination.

As the colorant, known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G,
5G, G), cadmium yellow, yellow iron oxide, loess, graphite, 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 Tan, Lead Zhu, Cadmium Red, Cad Muum Mercury Red, Antimony Vermilion,
Permanent Red 4R, Para Red, Phisay Red, Para Chlor Ortho Nitroaniline Red, Lysole Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine Min BS, Permanent Red (F2R, F4R, FRL, FRLL, F4R
H), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Lisor Rubin G
X, permanent red F5R, brilliant carmine 6B, pigment 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 rake,
Thioindigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermillion, 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, navy blue, anthraquinone blue, fast violet B, methyl violet lake, cobalt violet, manganese violet, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment green B, naphthol green B , Green Gold, Acid Green Lake, Malachite Green Lake, Phthalocyanine Green, Anthraquinone Green, Titanium Oxide, Zinc White, Lithobon and mixtures thereof can be used. The amount used is generally 10
0.1 to 50 parts by weight with respect to 0 parts by weight.

In addition, it is preferable that a wax is contained in a developer produced to give the toner itself a releasing property. The wax has a melting point of 40 to 120.
° C, and particularly preferably 50 to 110 ° C. If the melting point of the wax is too high, the fixability at low temperatures may be insufficient. On the other hand, if the melting point of the wax is too low, the offset resistance and durability may decrease.

The melting point of the wax can be determined by differential scanning calorimetry (DSC). That is, several mg of a sample is heated at a constant heating rate, for example (10 ° C. /
The melting peak value when ripening at min.) is defined as the melting point.

Examples of the wax that can be used in the present invention include solid paraffin wax, micro wax, rice wax, fatty acid amide wax, fatty acid wax, aliphatic monoketones, fatty acid metal salt wax, and fatty acid ester wax. And partially saponified fatty acid ester waxes, silicone varnishes, higher alcohols, and carnauba wax. Further, polyolefins such as low molecular weight polyethylene and polypropylene can also be used. In particular, a polyolefin having a softening point by a ring and ball method of 70 to 150 ° C is preferable, and a polyolefin having a softening point of 120 to 150 ° C is more preferable.

The particles containing the colorant and the resin can be produced, for example, by the following production method. The production method of the present invention has a step of mechanically mixing a developer component containing at least a binder resin, a main charge control agent and a pigment, a step of melt-kneading, a step of pulverizing, and a step of classifying. A toner manufacturing method can be applied. Further, in the step of mechanically mixing and the step of melt-kneading, there is also included a production method of returning and reusing powders other than the particles to be a product obtained in the step of pulverization or classification.

The powder (by-product) other than the product particles referred to herein means fine particles or coarse particles other than the components which become the product having the desired particle size obtained in the pulverizing step after the step of melt-kneading,
It means fine particles and coarse particles other than the components which are formed into a product having a desired particle size and are generated in a subsequent classification step. In the mixing step and the melt-kneading step of such a by-product, it is preferable to mix the raw materials and preferably the other raw material 99 to the by-product 1 at a weight ratio of the other raw material 50 to the by-product 50.

At least a colorant such as a binder resin and a pigment,
The mixing step of mechanically mixing the developer components including the by-products may be performed under ordinary conditions using an ordinary mixer or the like with rotating blades, and is not particularly limited.

After the above mixing step is completed, the mixture is then charged into a kneader and melt-kneaded. As the melt kneader, a uniaxial or biaxial continuous kneader or a batch kneader using a roll mill can be used. For example, a KTK twin screw extruder manufactured by Kobe Steel, a TEM extruder manufactured by Toshiba Machine Co., a twin screw extruder manufactured by KCK, a PCM twin screw extruder manufactured by Ikegai Iron Works, Bus A co-kneader or the like is preferably used.

It is important that the melt-kneading is performed under appropriate conditions so as not to cause the breaking of the molecular chains of the binder resin. Specifically, the melt-kneading temperature should be determined with reference to the softening point of the binder resin. If the temperature is lower than the softening point, cutting is severe, and if the temperature is too high, dispersion does not proceed.

After the completion of the above-mentioned melt-kneading step, the kneaded material is then pulverized. In this pulverization step, it is preferable to first perform coarse pulverization and then finely pulverize. At this time, a method of crushing by colliding with a collision plate in a jet stream, or crushing by a narrow gap between a mechanically rotating rotor and a stator is preferably used.

After the completion of the pulverizing step, the pulverized product is classified in an air stream by centrifugal force or the like, thereby producing a developer having a predetermined particle size, for example, an average particle size of 3 to 20 μm.

In addition, a method in which a resin in which a colorant or the like is dispersed in a resin is produced by heating or using a solvent or the like and dispersed in an air stream or an aqueous medium to the toner particle size, The so-called suspension polymerization method of dispersing and polymerizing a colorant or the like dispersed in an aqueous medium, the fine polymer particles obtained by emulsion polymerization in an aqueous medium are aggregated together with the colorant and aggregated. Resin particles containing a colorant can also be produced by a particle forming technique such as an emulsion polymerization aggregation method for growing to a toner particle size or a dispersion polymerization method for depositing insoluble particles from a monomer solution.

As the charge control agent particles in the present invention, known particles can be used, for example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxyamines, Examples include quaternary ammonium salts (including fluorinated quaternary ammonium salts), alkylamides, simple substances or compounds of phosphorus, tungsten simple substances or compounds, fluorine-based activators, metal salts of salicylic acid, and metal salts of salicylic acid derivatives. Specifically, Bontron 03, a nigrosine dye, and Bontron P-5, a quaternary ammonium salt
1, Bontron S-34 of a metal-containing azo dye, E-82 of an oxynaphthoic acid-based metal complex, E-84 of a salicylic acid-based metal complex, E-89 of a phenol condensate (all manufactured by Orient Chemical Industries), Quaternary ammonium salts TP-302 and TP-415 of molybdenum complexes and TN-105 of zirconium compounds (both manufactured by Hodogaya Chemical Industry Co., Ltd.), and copy charge PSY VP20 of quaternary ammonium salts
38, copy blue PR of a triphenylmethane derivative,
Copy charge NEG VP2 of quaternary ammonium salt
036, Copy Charge NX VP434 (both from Hoechst), LRA-901, LR- which is a boron complex
147 (manufactured by Nippon Kakarit Co.), copper phthalocyanine,
Examples include perylene, quinacridone, azo pigments, and other high molecular compounds having a functional group such as a sulfonic acid group, a carboxyl group, and a quaternary ammonium salt. Preferably, a crystalline compound which is easily broken into fine particles of 1 μm by stress or the like is more preferable. These charge control agent particles can also be put in advance inside the resin particles containing a colorant to reinforce chargeability.

The amount of the charge controlling agent particles to be stirred with the resin particles containing the colorant is preferably 0.01 to 2 parts by weight, more preferably 0.1 to 2 parts by weight, based on 100 parts by weight of the resin particles containing the colorant. 0.5 to 1 part by weight, most preferably 0.1 to 0.5 part by weight can be used.

As the external additive particles in the present invention, inorganic fine particles can be preferably used. The inorganic fine particles preferably have a primary particle size of 5 μm to 2 μm, particularly 5 μm to 2 μm.
It is preferably in the range of mμ to 500mμ. In addition, BET
The specific surface area by the method is preferably 20 to 500 m ² / g. The use ratio of the inorganic fine particles is 0.0% of the toner.
It is preferably 1 to 5% by weight, particularly 0.01 to 5% by weight.
Preferably it is 2.0% by weight.

Specific examples of the inorganic fine particles include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, silica sand, clay, mica, and silica ash. Stone, diatomaceous earth, chromium oxide, cerium oxide, red iron oxide, antimony trioxide, magnesium oxide,
Zirconium oxide, parium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride, and the like can be given.

In addition, polymer fine particles such as polystyrene obtained by soap-free emulsion polymerization, suspension polymerization, or dispersion polymerization, polycondensation systems such as methacrylate or acrylate copolymers, silicones, benzoguanamines, and nylons; Polymer particles made of a curable resin may be used.

Such an external additive is subjected to a surface treatment,
Hydrophobicity can be increased to prevent deterioration of flow characteristics and charging characteristics even under high humidity. For example, silicone oil, a silane coupling agent, a silylating agent, a silane coupling agent having an alkyl fluoride group, an organic titanate coupling agent, an aluminum coupling agent, and the like are preferable surface treatment agents.

Further, the external additive particles in the present invention also include a cleaning property improving agent for removing the developer after transfer remaining on the photoreceptor and the primary transfer medium. Examples include lubricant particles such as fatty acid metal salts such as zinc stearate, calcium stearate, and stearic acid, and polymer fine particles such as polyethylene and polypropylene.
The polymer fine particles preferably have a relatively narrow particle size distribution and a volume average particle size of 0.01 to 1 μm.

In the surface treatment method for an electrophotographic toner according to the present invention, the particles containing the colorant and the resin and the charge control agent particles are charged into the processing apparatus, and the peripheral speed of the stirring blade is preferably 50 to 15
0 m / sec, more preferably 80 to 120 m / sec
The processing may be performed for several seconds to several tens of minutes. This process may be repeated several times to several tens of times.

In order to enhance the fluidity, the above-mentioned external additives can be added and mixed. The timing of adding the external additive is a method of adding the external additive before adding the charge control agent particles to the particles containing the colorant and the resin, a method of adding all at the same time, a method of adding after the treatment with the charge control agent particles, for example, a part. Using an external additive that is effective in improving the fluidity of the particles during processing of the particles containing the colorant and the resin and the particles of the charge control agent,
The remaining external additive particles having an effect on the developing property and the transfer property can be appropriately used in accordance with the purpose, such as a method of subsequently mixing the particles.

Further, the external additive particles in the present invention also include a cleaning property improving agent for removing the developer after transfer remaining on the photoreceptor and the primary transfer medium. For example, lubricant particles such as fatty acid metal salts such as zinc stearate, calcium stearate, and stearic acid, and polymer fine particles such as polyethylene and polypropylene can be used. The polymer fine particles preferably have a relatively narrow particle size distribution and a volume average particle size of 0.01 to 1 μm.

When the toner of the present invention is used for a two-component developer, it may be mixed with a magnetic carrier, and the content ratio of the carrier to the toner in the developer is 100 parts by weight of the carrier. -10 parts by weight is preferred. As the magnetic carrier, iron powder having a particle diameter of about 20 to 200 μm,
Conventionally known materials such as ferrite powder, magnetite powder, and magnetic resin carrier can be used.

As the coating material, amino resin,
For example, urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, epoxy resin and the like can be mentioned. Further, polyvinyl and polyvinylidene resins, for example, acrylic resins, polymethyl methacrylate resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins, polystyrene resins such as polystyrene resins and styrene acrylic copolymer resins, polystyrene resins Halogenated olefin resins such as vinyl chloride, polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin, polycarbonate resins, polyethylene resin, polyvinyl fluoride resin, polyvinylidene fluoride resin, polytrifluoroethylene resin, polyhexa Fluoropropylene resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene and vinylidyl fluoride Fluoro such as terpolymers of emission and non-fluoride monomers including, and silicone resins. Further, if necessary, a conductive powder or the like may be contained in the coating resin.

As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide and the like can be used. These conductive powders preferably have an average particle size of 1 μm or less. When the average particle diameter is larger than 1 μm, it becomes difficult to control the electric resistance.

The toner of the present invention can be used as a one-component magnetic toner or a non-magnetic toner without using a carrier.

[0049]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited to only these Examples. In the following examples, parts and percentages are by weight unless otherwise specified.

(Master Batch for Cyan Toner) 600 parts of water 1200 parts of Pigment Blue 15: 3 water-containing cake (50% of solid content) is thoroughly stirred with a flasher. Here, polyester resin (acid value; 3, hydroxyl value; 25, Mn; 4500)
(0, Mw / Mn; 4.0, Tg; 60 ° C.), and kneaded at 150 ° C. for 30 minutes, kneaded at 150 ° C. for 30 minutes, kneaded with 1000 parts of xylene, further kneaded for 1 hour, removed water and xylene, rolled and cooled, and cooled by a pulperizer. Then, the mixture was further passed through a three-roll mill for two passes to obtain a master batch pigment for cyan toner.

Next, a toner is prepared in the following composition ratio using the following binder resin and release agent and the above masterbatch for cyan toner. Polyester resin A (acid value: 35 KOHmg / g) 90 parts Masterbatch for cyan toner 5 parts The above materials were mixed by a mixer, then melt-kneaded by a two-roll mill, and the kneaded product was rolled and cooled. Thereafter, a jet plate mill (I-2 type mill; manufactured by Nippon Pneumatic Industries Co., Ltd.) using a jet mill and a wind classifier (DS classifier;
Nippon Pneumatic Industries, Ltd.) to obtain black colored particles having a weight average diameter of 6.5 μm.

Example 1 As shown in FIG. 2, the obtained colored particles were treated under the following conditions by mounting a cylindrical member on the top of a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.). Colored particles 100 parts Charge control agent (E-84, manufactured by Orient Chemical Co., Ltd.) 0.1 parts The peripheral speed of the stirring blade is set to 30 m / sec, the operation is performed for 2 minutes, and the operation is suspended for 1 minute for 3 cycles to obtain toner particles. (Total processing time: 6 minutes). The adhesion state (discharge amount) in the container was 712 g, and the stirring Q / M for 15 seconds was -21.3 μC / g,
The 0 minute stirring Q / M was −23.4 μC / g, the charging start rate was 91%, the background stain was 0.09, and the durability was 2,000 sheets.

Comparative Example 1 A treatment was performed in the same manner as in Example 1 except that the treatment was performed using a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.) shown in FIG. Adhesion condition (discharge amount) in the container is 631 g, stirring Q / M for 15 seconds is -1
8.2 μC / g, stirring for 10 minutes Q / M is −25.4 μC /
g, charging rise rate is 72%, background stain is 0.17,
The durability was 1,000 sheets.

Example 2 As shown in FIG. 3, a cylindrical member was mounted inside a treatment tank on a Q-type mixer (manufactured by Mitsui Mining Co., Ltd.), and the mixture was treated under the following conditions. Colored particles 100 parts Charge control agent (E-84, manufactured by Orient Chemical Co.) 0.10 parts (average particle size of the charge control agent by microscopic observation is 1.2 μm) The peripheral speed of the stirring blade is set to 100 m / sec. Three cycles of a 2-minute operation and a 1-minute pause were performed to obtain toner particles (total processing time: 6 minutes). The adhesion state (discharge amount) in the container was 780 g, and the stirring Q / M for 15 seconds was −23.5 μC / g,
The 0 minute stirring Q / M was −23.4 μC / g, the charging start rate was 100%, the background stain was 0.02, and the durability was 150,000 sheets.

Comparative Example 2 The cylindrical member existing inside the processing tank was removed from the mixer shown in FIG. 3, and the processing was carried out in the same manner as in Example 2 except for the state shown in FIG. Adhesion status in container (discharge amount)
Is 520 g, stirring Q / M for 15 seconds is −18.7 μC / g,
The 10 minute stirring Q / M was -26.2 μC / g, the charging rise rate was 71.3%, the background stain was 0.03, and the durability was 60,000 sheets.

Examples 3 to 6 and Comparative Examples 3 to 6 Each treatment was performed under the conditions shown in Table 1. Table 2 shows the results.

[0057]

[Table 1]

Measurement method / Evaluation method (1) Adhesion condition in container (discharge amount) 1.00 kg of colored particle powder was treated, and a stirring blade was set to 20
After rotating at m / sec for 10 seconds, the weight of the colored particle powder discharged from the discharge port was determined. (2) 15 second stirring Q / M silicon resin coated ferrite carrier (average particle size 50
μm) and 2.5 parts of the test toner were placed in a stainless steel pot up to 30% of the internal volume, stirred for 15 seconds at a stirring speed of 100 rpm, and determined by a blow-off method. (3) 10-minute stirring Q / M The charge amount when stirring for 10 minutes was determined in the same manner as in the 15-minute stirring Q / M. (4) Charge rise rate (%) (15-second stirring Q / M value) / (10-minute stirring Q / M value) (5) Background dirt Using a dedicated chart (5% image area) with Imagio MF6550 manufactured by Ricoh Company ), The blank image was stopped during the development after running 10,000 sheets of A4 paper, the toner on the photoreceptor after the development was transferred to the tape, and the difference between the image density of the untransferred tape and the 938 spectrodensitometer ( X-Rite). (6) Durability With Imagio MF6550 manufactured by Ricoh Co., Ltd., A4 paper of a special chart (5% image area) is continuously run, and a solid black image is developed every 1,000 sheets, and an image ID is 938 spectrodensitometer ( (Manufactured by X-Rite Co., Ltd.), and when the image density was reduced to less than 80% of the initial image density, the life of the developer was determined.

[0059]

[Table 2]

[0060]

As described above, according to the present invention, as compared with the prior art, a small amount of a charge control agent can be used to obtain a proper charge characteristic in an actual machine and a high charge efficiency. It is possible to provide a method for producing an electrophotographic toner capable of providing image quality stably over a long period of time.

[Brief description of the drawings]

FIG. 1 is a sectional view of a container used in a conventional method for producing an electrophotographic toner.

FIG. 2 is a sectional view of a container used in the method for producing an electrophotographic toner according to the present invention.

FIG. 3 is a cross-sectional view of another container used in the method for producing an electrophotographic toner of the present invention.

FIG. 4 is a cross-sectional view showing the dimensions and shape of a container used in the method for producing an electrophotographic toner of the present invention.

FIG. 5 is a sectional view of a container used in Comparative Example 2.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shigeru Emoto 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Tsuneshin Suginama 1-3-6 Nakamagome, Ota-ku, Tokyo Share Inside Ricoh Company (72) Inventor Yuji Yamashita 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh Company (72) Inventor Chiaki Tanaka 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh Company F Term (reference) 2H005 AA08 AB10 DA01

Claims (11)

[Claims] 1. A method for producing an electrophotographic toner in which particles containing a colorant and a resin, and particles comprising a charge control agent particle or an external additive are mixed in a container, wherein a stirring blade is arranged at the bottom of the container tank. Then, a cylindrical member is arranged on an extension of the drive shaft of the stirring blade, and the object to be processed emitted by the stirring blade is received by the inner wall surface of the cylindrical member to reduce the kinetic energy of the object to be processed. A process of mixing particles comprising a colorant and a resin and particles comprising a charge control agent particle or an external additive by using a mixer having a mechanism for re-supplying an object to be processed to a stirring blade at the bottom of the tank. Of producing an electrophotographic toner. 2. A method for producing an electrophotographic toner in which particles containing a colorant and a resin and particles of a charge control agent or particles of an external additive are mixed and mixed in a container. Is a horizontal disk, and a stirring blade having a drive shaft vertically penetrating the center of the tank bottom is arranged at the tank bottom, and the stirring is performed to discharge an object to be processed upward from the outer periphery of the tank bottom along the inner wall of the processing tank. It has a blade, and a cylindrical member is arranged inside the container on the extension of the drive shaft of the stirring blade, and the object to be processed released by the stirring blade is received by the inner wall surface of the cylindrical member to be processed. Using a mixer having a mechanism to reduce the kinetic energy of the object and re-supply the object to be processed to the stirring blade at the bottom of the tank, the particles containing the colorant and the resin and the particles comprising the charge control agent particles or the external additive are separated from each other. Manufacturing method of electrophotographic toner characterized by mixing treatment Law. 3. The method for producing an electrophotographic toner according to claim 1, wherein the cylindrical member is a cylindrical tube whose cross section is a perfect circle. 4. The shaft sealing air is discharged to the outside of the container through the cylindrical member.
The method for producing an electrophotographic toner according to any one of the above. 5. The electrophotographic toner according to claim 1, wherein the height H inside the container and the length L of the cylindrical member have the following relationship. Manufacturing method. [Equation 1] 1/10 · H ≦ L 6. The inner diameter R1 of the container and the inner diameter R of the cylindrical member.
2. The following relationship is established between the two:
The method for producing an electrophotographic toner according to any one of the above. [Formula 2] 1/10 · R1 ≦ R2 7. The method for producing an electrophotographic toner according to claim 1, wherein the tip of the cylindrical member has a trumpet shape. 8. The method for producing an electrophotographic toner according to claim 1, wherein a root portion of the cylindrical member is rounded. 9. A method for producing an electrophotographic toner in which particles containing a colorant and a resin and particles of a charge control agent are mixed in a container using a rotating body, wherein the peripheral speed of the stirring blade is 50 to 150 m.
9. The method for producing an electrophotographic toner according to claim 1, wherein the mixing is performed at a rate of / sec. 10. A method for producing an electrophotographic toner in which particles containing a colorant and a resin and charge control agent particles are mixed in a container using a rotating body, wherein the particles containing the colorant and the resin and the charge control agent are mixed. After the particles are mixed in advance at a peripheral speed of the rotating body of 50 m / sec or less for a predetermined time, the peripheral speed of the rotating body is 50 m / s.
The method for producing an electrophotographic toner according to any one of claims 1 to 9, wherein the mixture is mixed at ec or more. 11. A method for producing an electrophotographic toner in which particles containing a colorant and a resin and particles of a charge control agent are mixed using a rotator in a container, wherein the weight average particle diameter of the charge control agent is 3 μm. The method for producing an electrophotographic toner according to claim 1, wherein: