JP2008139502A - Method for producing toner, toner, two component developer, image forming apparatus and process cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing toner having excellent cleaning properties and also capable of improving a yield upon the production of toner. <P>SOLUTION: The method for producing toner comprises: a granulation step where an organic solvent phase composed of a toner composition at least including a binding resin and/or a monomer for a binding resin is emulsified and/or dispersed into a water base medium phase, so as to granulate toner; and a classification step for classifying the toner for obtaining toner with prescribed particle diameters; wherein fine powder as the toner with particle diameters smaller than the above prescribed particle diameters removed by the above classification step when the above toner is produced in an another lot is mixed into the water base medium phase. Also the toner produced by the method, a two component developer comprising the toner, and an image forming apparatus and a process cartridge using the toner are provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a toner manufacturing method, a toner, a two-component developer, an image forming apparatus, and a process cartridge.

  In electrophotography, a photoconductive substance is used to form an electrical latent image on a photoreceptor, and the latent image is developed with toner to form a toner image, and the toner image is formed on a recording material such as paper. In this method, after transfer, the image is fixed on a recording sheet by heating, pressure, or the like. In recent years, high-speed copying and high image quality have been demanded for electrophotography.

  As a method for producing a toner, a colorant such as a dye and a pigment and an additive such as a charge control agent are melt-mixed in a thermoplastic resin to make it uniform. There is known a pulverization method for producing a toner by pulverizing and classifying the mixture with a fine pulverizer and a classifier.

  In a toner manufactured by a pulverization method, when a releasing material such as wax is added, the dispersibility of the releasing material needs to be at a sufficient level. For this reason, it is necessary to maintain a certain degree of viscosity at the kneading temperature with the resin, and the content of the releasable substance to be about 5 parts by mass or less per 100 parts by mass of the toner. Due to such restrictions, there is a problem that there is a limit to the toner fixability by the pulverization method.

  Further, in the pulverization method, unless the solid fine particles such as the colorant are completely dispersed in the resin, there is a problem in that the distribution of the toner is unevenly distributed and the toner developing characteristics are abnormal.

  Furthermore, the image resolution, solid portion uniformity, gradation reproducibility, and the like largely depend on the toner characteristics, particularly the toner particle size, and a toner having a smaller particle size can obtain a higher quality image. . For this reason, recent printers and high-quality copiers often use small particle size toner. However, when the toner particles are reduced in size by the pulverization method, there is a problem that the volume average particle size is about 5 μm.

  As another method for producing a toner, a method for producing a polymerized toner (polymerization method) is proposed in which at least a polymerizable monomer component having a polymerizable monomer is subjected to suspension polymerization, and at the same time, toner particles are obtained. Yes. In this polymerization method, a polymerizable monomer composition is obtained by uniformly dissolving or dispersing a polymerizable monomer and a colorant. The polymerizable monomer composition is dispersed in a continuous phase such as an aqueous phase containing a dispersion stabilizer using a suitable stirrer and simultaneously undergoes a polymerization reaction to have a desired particle size. Toner particles are obtained. Therefore, there is no restriction like the above-mentioned pulverized toner and there are various advantages and attention has been paid.

  In addition, the polymerized toner produced by the polymerization method can encapsulate the release agent component in the toner particles, so that the content of the release agent can be increased as compared with the pulverization toner, and the dispersibility of the release agent can be increased. Can be satisfied at the same time. Moreover, also about the dispersibility of a coloring agent, it can melt | dissolve or disperse | distribute uniformly with another additive in a polymerizable monomer. Furthermore, since a desired particle size and particle size distribution can be obtained depending on the dispersion and granulation conditions, it is possible to cope with the formation of toner having a small particle size.

  However, the toner particles obtained by the polymerization method are spherical and have a drawback of poor cleaning properties. In development and transfer with a low image area ratio, there is little transfer residual toner, and poor cleaning is unlikely to be a problem. However, in a case where the image area ratio is high, such as a photographic image, untransferred toner may be generated as a transfer residual toner on the photosensitive member due to poor paper feed or the like. There was a problem that would occur. Further, there is a problem that the charging roller for charging the photosensitive member in contact with the photosensitive member is contaminated and the original charging ability cannot be exhibited.

  Furthermore, depending on the polymerization reaction conditions and the toner formulation, during the reaction, fine particles that are fine particles that are toners having a particle size outside the predetermined range, and coarse powder that is large particles generated by particle aggregation are generated. The point of adhering to a stirring blade is also a problem. Even under production conditions where the particle size distribution width is sharp and fine powder and coarse powder are suppressed as much as possible, mixing of these fine powder and coarse powder cannot be completely excluded.

  In addition, when toner particles other than predetermined in the polymerized toner are formed in any unexpected form, the particles are formed as a core-shell structure having at least two layers by inclusion of a releasable component and a low energy fixing component. Because of the design, it cannot be simply reused like toner produced by the pulverization method. This is an important examination item to be solved in the toner production yield.

  For this reason, a method has been proposed in which non-predetermined toner particles are dissolved in a polymerizable monomer and reused (see, for example, Patent Documents 1 and 2).

  There is also proposed a method of kneading and pulverizing unspecified tetrahydrofuran-insoluble matter generated during the preparation of the polymerized toner, and charging it into a single monomer or composition for reuse (for example, see Patent Document 3). ).

Further, in a method for producing a toner synthesized in an aqueous medium, a method has also been proposed in which the coarse powder separated in the classification step is pulverized or crushed and reused as toner particles having a predetermined particle size (for example, (See Patent Document 4).
JP-A-10-301330 JP 2005-128456 A Japanese Patent Laid-Open No. 2004-4798 JP 2004-233389 A

  However, the methods for reusing the non-predetermined toner particles disclosed in Patent Documents 1 and 2 have a problem that only the soluble component in the non-predetermined toner with respect to the polymerizable monomer is used and the insoluble component cannot be used. there were.

  In the method of reusing toner particles other than the predetermined toner disclosed in Patent Document 3, the particle diameter becomes coarse when the toner powder to be reused is mixed, dispersed, or dissolved in the organic solvent phase. . Therefore, it is difficult to obtain a predetermined particle size and particle size distribution, and there is a problem that it is difficult to cope with the formation of a small particle size toner.

  In addition, the method of reusing non-predetermined toner particles disclosed in Patent Document 4 has a lack of image density, fogging, and cleanability due to re-use of non-predetermined toner in recent years when higher image quality is required. There has been a problem that image quality defects such as insufficiency occur.

  The present invention has been made in view of the above points, and is a method for producing a toner that is excellent in cleaning properties and can improve the yield in toner production, the toner produced by the method, and the toner. It is an object of the present invention to provide a two-component developer containing an image forming apparatus and a process cartridge using the toner.

  In order to achieve the above object, the present invention is characterized by the following means.

  The method for producing a toner of the present invention comprises preparing an toner by emulsifying and / or dispersing an organic solvent phase comprising a toner composition containing at least a binder resin and / or a binder resin monomer in an aqueous medium phase. In a toner manufacturing method having a granulating step for granulating and a classification step for classifying the toner in order to obtain a toner having a predetermined particle size, when the toner is manufactured in another lot in the aqueous medium phase The fine powder, which is the toner smaller than the predetermined particle diameter, removed by the classification step is mixed.

  The toner of the present invention is manufactured by the toner manufacturing method of the present invention.

  The two-component developer of the present invention contains the toner of the present invention.

  An image forming apparatus according to the present invention includes a charging unit that uniformly charges an image carrier, a developing unit that develops an electrostatic latent image formed on the image carrier into a toner image, and an image on the image carrier. In the image forming apparatus including a fixing unit that fixes the toner image on the recording material, the developing unit holds the toner of the present invention.

  An image forming apparatus according to the present invention includes a charging unit that uniformly charges an image carrier, a developing unit that develops an electrostatic latent image formed on the image carrier into a toner image, and an image on the image carrier. In the image forming method including a transfer unit that transfers the toner image onto a film and a heat fixing unit that heat-fixes the toner image on the film onto a recording material, the developing unit uses the toner of the present invention. Hold.

  The process cartridge of the present invention is detachable from the main body of the image forming apparatus, and includes at least a photosensitive member, a charging unit, a developing unit, and a cleaning unit. The means holds the toner of the present invention.

  According to the present invention, a toner production method that is excellent in cleaning properties and can improve the yield in toner production, a toner produced by the method, a two-component developer containing the toner, and the toner It is possible to provide an image forming apparatus and a process cartridge to be used.

  Next, the best embodiment of the present invention will be described with reference to the drawings.

(Organic solvent phase)
(Organic solvent)
The material used for manufacturing the toner of this embodiment will be described. The organic solvent used in the exemplary embodiment is not particularly limited as long as it is a solvent that can dissolve and / or disperse the toner composition. The organic solvent is preferably volatile in that the boiling point of the solvent is less than 150 ° C. and removal is easy. Examples of such solvents include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, methyl acetate, ethyl acetate, methyl ethyl ketone. , Acetone, and tetrahydrofuran can be used alone or in combination of two or more. Of the above organic solvents, methyl acetate and ethyl acetate are particularly preferred because of their high volatility with respect to the toner. The amount of the organic solvent used is usually 40 to 300 parts by mass, preferably 60 to 140 parts by mass, and more preferably 80 to 120 parts by mass with respect to 100 parts by mass of the toner solid component. .

(Functional group-containing polyester resin)
In this embodiment, a polyester prepolymer having an isocyanate group can be used as the modified polyester resin. The polyester prepolymer (A) having an isocyanate group is a polycondensate of polyol (1) and polycarboxylic acid (2), and a polyester having an active hydrogen group was further reacted with polyisocyanate (3). Things. Examples of the active hydrogen group possessed by the polyester include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), an amino group, a carboxyl group, and a mercapto group. Among these, an alcoholic hydroxyl group is preferable.

  Examples of the polyol (1) include a diol (1-1) and a tri- or higher valent polyol (1-2). (1-1) alone or (1-1) and a small amount of (1-2) It is preferable to use a mixture. Examples of the diol (1-1) include alkylene glycol (such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, and 1,6-hexanediol), alkylene ether glycol ( Diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol), alicyclic diols (such as 1,4-cyclohexanedimethanol and hydrogenated bisphenol A), bisphenols (bisphenol A) Bisphenol F, bisphenol S, etc.), alkylene oxides of the above-mentioned alicyclic diols (ethylene oxide, propylene oxide, butylene oxide, etc.) ) Adducts, and alkylene oxide (ethylene oxide bisphenols mentioned above, propylene oxide, and butylene oxide) such as adduct. Among them, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols, alkylene oxide adducts of bisphenols and A combination of alkylene glycols having 2 to 12 carbon atoms.

  Examples of the trihydric or higher polyol (1-2) include trihydric to octahydric or higher polyhydric aliphatic alcohols (such as glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, and sorbitol), and trihydric or higher phenols. (Trisphenol PA, phenol novolak, cresol novolak, etc.), and alkylene oxide adducts of the above-mentioned trihydric or higher polyphenols.

  Examples of the polycarboxylic acid (2) include dicarboxylic acid (2-1) and trivalent or higher polycarboxylic acid (2-2), (2-1) alone or (2-1), and a small amount. It is preferable to use a mixture of (2-2).

  Examples of the dicarboxylic acid (2-1) include alkylene dicarboxylic acids (such as succinic acid, adipic acid, and sebacic acid), alkenylene dicarboxylic acids (such as maleic acid and fumaric acid), and aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid). Acid, naphthalenedicarboxylic acid and the like). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms.

  Examples of the trivalent or higher polycarboxylic acid (2-2) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid).

  Moreover, as polycarboxylic acid (2), you may make it react with polyol (1) using the acid anhydride or lower alkyl ester (Methyl ester, ethyl ester, isopropyl ester, etc.) of the compound mentioned above.

  In order to adjust the polyester having an alcoholic hydroxyl group at the terminal by a polycondensation reaction, the ratio of the polyol (1) and the polycarboxylic acid (2) is equivalent to the equivalent ratio of the hydroxyl group [OH] and the carboxyl group [COOH] [OH] / [COOH] is usually 2/1 or more and 1/1 or less, preferably 1.5 / 1 or more and 1/1 or less, and more preferably 1.3 / 1 or more and 1.02 / 1 or less.

  Examples of the polyisocyanate (3) used for preparing a polyester prepolymer by reacting with an alcoholic hydroxyl group of polyester include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, and 2,6-diisocyanatomethyl carbonate). Proate), alicyclic polyisocyanate (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.), aromatic diisocyanate (tolylene diisocyanate, diphenylmethane diisocyanate, etc.), araliphatic diisocyanate (α, α, α ', α'- Tetramethylxylylene diisocyanate), isocyanurates, and the above polyisocyanates blocked with phenol derivatives, oximes, caprolactam, etc. And a combination of two or more of these.

  The use ratio of the polyisocyanate is usually 5/1 or more and 1/1 or less, preferably 4 /, where the equivalent ratio of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group is [NCO] / [OH]. 1 or more and 1.2 / 1 or less, more preferably 2.5 / 1 or more and 1.5 / 1 or less. When the value of [NCO] / [OH] exceeds 5, the low-temperature fixability deteriorates. If the molar ratio of [NCO] is less than 1, the urea content in the modified polyester will be low, and the hot offset resistance will deteriorate.

  The number of isocyanate groups contained per molecule in the prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 in average, more preferably 1.8 to 2.5 in average. Or less. If it is less than 1 per molecule, the molecular weight of the modified polyester after crosslinking and / or elongation becomes low, and the hot offset resistance deteriorates.

(Combination with non-reactive low molecular weight polyester)
In the present embodiment, it is important not only to use the above-described modified polyester (A) alone, but also to contain an unmodified polyester (C) that is not modified with the (A) as a toner binder component. is there. By using (C) in combination, the low-temperature fixability and the glossiness when used in a full-color apparatus are improved. Examples of (C) include the same polycondensates of polyol (1) and polycarboxylic acid (2) as in the polyester component of (A), and preferred ones are also the same as (C). (C) is not limited to unmodified polyester, but may be modified with a chemical bond other than a urea bond, and may be modified with a urethane bond, for example. It is preferable that (A) and (C) are at least partially compatible in terms of low-temperature fixability and hot offset resistance. Accordingly, the polyester component (A) and (C) preferably have similar compositions. In the case of containing (A), the weight ratio of (A) and (C) is usually 5/95 or more and 75/25 or less, preferably 10/90 or more and 25/75 or less, more preferably 12/88 or more and 25 / 75 or less, particularly preferably 12/88 or more and 22/78 or less. When the weight ratio of (A) is less than 5%, the hot offset resistance is deteriorated, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

  The peak molecular weight measured by GPC (gel permeation chromatography) using polyester (C) as a sample is usually 1000 or more and 30000 or less, preferably 1500 or more and 10,000 or less, and more preferably 2000 or more and 8000 or less. If it is less than 1000, heat-resistant storage stability will deteriorate, and if it exceeds 10,000, low-temperature fixability will deteriorate.

  The hydroxyl value of (C) is preferably 5 KOHmg / g or more, more preferably 10 KOHmg / g or more and 120 KOHmg / g or less, and particularly preferably 20 KOHmg / g or more and 80 KOHmg / g or less. When the hydroxyl group is less than 5 KOHmg / g, it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

  The acid value of (C) is usually from 0.5 KOH mg / g to 40 KOH mg / g, preferably from 5 KOH mg / g to 35 KOH mg / g. An acid value that is too high is not preferred because it tends to be negatively charged. In addition, those exceeding the above-mentioned acid value range are easily affected by the environment in a high temperature and high humidity environment and a low temperature and low humidity environment, and are liable to cause image deterioration.

(Active hydrogen-containing compounds)
As described below, the above-mentioned polyester prepolymer (A) having an isocyanate group is made to have a higher molecular weight by being subjected to elongation and / or crosslinking reaction with an active hydrogen compound.

  In this embodiment, amines can be used as a crosslinking agent and / or an extender.

  As amines (B), diamine (B1), trivalent or higher polyamine (B2), aminoalcohol (B3), aminomercaptan (B4), amino acid (B5), and amino acids B1 to B5 blocked (B6) etc. are mentioned.

  Examples of the diamine (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, and 4,4′diaminodiphenylmethane), alicyclic diamines (4,4′-diamino-3,3′dimethyldicyclohexylmethane, diaminecyclohexane). And isophorone diamine), and aliphatic diamines (such as ethylene diamine, tetramethylene diamine, and hexamethylene diamine).

  Examples of the trivalent or higher polyamine (B2) include diethylenetriamine and triethylenetetramine.

  Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline.

  Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan.

  Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid.

  Examples of the blocked amino group of B1 to B5 (B6) include ketimine compounds obtained from the aforementioned amines and ketones of B1 to B5 (such as acetone, methyl ethyl ketone, and methyl isobutyl ketone), and oxazoline compounds. It is done. Among these amines (B), preferred are (B1) or a mixture of (B1) and a small amount of (B2).

  Furthermore, if necessary, the molecular weight of the modified polyester after completion of the reaction can be adjusted by using a terminator for crosslinking and / or elongation. Examples of the terminator include monoamines (such as diethylamine, dibutylamine, butylamine, and laurylamine), and those obtained by blocking them (ketimine compounds).

  The ratio of the amines (B) is the equivalent ratio of the isocyanate groups [NCO] in the prepolymer (A) having isocyanate groups and the amino groups [NHx] in the amines (B) [NCO] / [NHx]. As above, it is usually from 1/2 to 2/1, preferably from 1.5 / 1 to 1 / 1.5, more preferably from 1.2 / 1 to 1 / 1.2. When [NCO] / [NHx] is greater than 2 or less than 1/2, the molecular weight of the modified polyester is lowered, and the hot offset resistance is deteriorated.

(Characteristics of toner binder)
In the present embodiment, as described above, a urea-modified polyester resin obtained by a reaction with a polyester prepolymer (A) and an amine (B) is used as a toner binder. In addition, other components such as non-reactive polyester (including a resin used in the case of a colorant master batch) are also used in combination.

  In this embodiment, the glass transition point (Tg) of the toner binder is usually 40 ° C. or higher and 70 ° C. or lower, preferably 45 ° C. or higher and 55 ° C. or lower. When the glass transition point is less than 40 ° C., the heat-resistant storage stability of the toner is deteriorated, and when the glass transition point exceeds 70 ° C., the low-temperature fixability becomes insufficient. Due to the coexistence of the crosslinked and / or elongated polyester resin, the toner for developing an electrostatic charge image of the exemplary embodiment exhibits good storage stability even when the glass transition point is low as compared with a known polyester-based toner.

  As the storage elastic modulus of the toner, the temperature (TG ′) at which the measurement frequency is 20 Hz becomes 1000 Pa is usually 100 ° C. or higher, preferably 110 ° C. or higher and 200 ° C. or lower. If it is less than 100 degreeC, hot offset resistance will deteriorate.

  Regarding the viscosity of the toner, the temperature (Tη) at which the measurement frequency is 20 Hz becomes 100 Pa · s is usually 180 ° C. or lower, preferably 90 ° C. or higher and 160 ° C. or lower. If it exceeds 180 ° C., the low-temperature fixability deteriorates. That is, from the viewpoint of achieving both low-temperature fixability and hot offset resistance, TG ′ is preferably higher than Tη. In other words, the difference between TG ′ and Tη (TG′−Tη) is preferably 0 ° C. or higher. More preferably, the difference between TG ′ and Tη (TG′−Tη) is 10 ° C. or more, and particularly preferably 20 ° C. or more. Further, from the viewpoint of achieving both heat-resistant storage stability and low-temperature fixability, the difference between Tη and Tg is preferably 0 ° C. or higher and 100 ° C. or lower. More preferably, the difference between Tη and Tg is 10 ° C. or higher and 90 ° C. or lower, and particularly preferably 20 ° C. or higher and 80 ° C. or lower.

(Measurement of glass transition point)
For the measurement of the glass transition point of the present embodiment, a TG-DSC system TAS-100 manufactured by Rigaku Corporation was used. First, about 10 mg of a sample is placed in an aluminum sample container, which is placed on a holder unit and set in an electric furnace. First, after heating from room temperature to 150 ° C. at a temperature rising rate of 10 ° C./min, the sample was allowed to stand at 150 ° C. for 10 minutes, the sample was cooled to room temperature and allowed to stand for 10 minutes, and the temperature rising rate was again increased to 150 ° C. under a nitrogen atmosphere. DSC measurement was carried out by heating at / min. The glass transition point was calculated from the contact point between the tangent line and the base line of the endothermic curve near the glass transition point using an analysis system in the TAS-100 system.

(Aqueous medium phase)
(Aqueous medium)
In the present embodiment, the aqueous medium in which the resin fine particles described later are dispersed to form the aqueous medium phase may be water alone, or a solvent miscible with water may be used in combination. Examples of miscible solvents include alcohols (such as methanol, isopropanol, and ethylene glycol), dimethylformamide, tetrahydrofuran, cellosolves, and lower ketones (such as acetone and methyl ethyl ketone). These can be used alone or in combination of two or more.

(Resin fine particles)
The resin fine particles in the toner of this embodiment are added in the production process in order to control the toner shape (circularity, particle size distribution, etc.) described below. Further, as described below, the fine particles are bonded to the surface portion when an organic solvent phase and an active hydrogen-containing compound (amines) are dispersed in an aqueous medium to form organic dispersed particles. Conceivable. As a result, like the external additives described below, it is considered that the toner base particles obtained are unevenly distributed mainly on the surface portion.

  In this embodiment, it is important that the amount of resin fine particles contained in the obtained toner particles after the external additive treatment is 0.5 wt% or more and 5.0 wt% or less. When the content of the resin fine particles is less than 0.5% by weight, the storage stability of the toner is deteriorated, and blocking is observed during storage and in the developing machine. On the other hand, when the content of the resin fine particles is 5.0% by weight or more, the resin fine particles inhibit the exudation of the wax, the wax releasing effect cannot be obtained, and the occurrence of offset is observed.

  Further, it is important that the glass transition point (Tg) of the resin fine particles is 40 ° C. or more and 100 ° C. or less and the weight average molecular weight is 9000 or more and 200,000 or less. When the glass transition point of the resin fine particles is less than 40 ° C. and / or the weight average molecular weight of the resin fine particles is less than 9000, the storage stability of the toner is deteriorated, and blocking occurs during storage and in the developing machine. Furthermore, when the glass transition point of the resin fine particles is 80 ° C. or higher and / or the weight average molecular weight of the resin fine particles is 200,000 or higher, the resin fine particles inhibit the adhesion between the toner and the fixing paper, and the minimum fixing temperature increases. Is seen.

  The content of the resin fine particles can be measured by analyzing a substance caused by the resin fine particles, not by the toner particles, using a pyrolysis gas chromatograph mass spectrometer, and calculating from the peak area.

  The detector is preferably a mass spectrometer, but is not particularly limited. The dispersion and blending amount of the resin fine particles in the aqueous medium may be set so as to satisfy the above-described conditions related to the content of the resin fine particles, but usually within a range of about 0.5% by weight to 10% by weight. It is said.

  The resin fine particles may be any resin as long as it can form an aqueous dispersion, and may be a thermoplastic resin or a thermosetting resin. For example, a vinyl resin, a polyurethane resin, an epoxy resin, a polyester resin, a polyamide resin, Examples thereof include polyimide resins, silicon resins, phenol resins, melamine resins, urea resins, aniline resins, ionomer resins, and polycarbonate resins. As the resin fine particles, two or more of the above resins may be used in combination. Of these, vinyl resins, polyurethane resins, epoxy resins, polyester resins, and combinations thereof are preferred because an aqueous dispersion of fine spherical resin particles can be easily obtained.

  The vinyl resin is a polymer obtained by homopolymerization or copolymerization of a vinyl monomer, such as a styrene- (meth) acrylate resin, a styrene-butadiene copolymer, a (meth) acrylic acid-acrylate polymer, Examples thereof include styrene-acrylonitrile copolymers, styrene-maleic anhydride copolymers, and styrene- (meth) acrylic acid copolymers.

(Toner fine powder)
When toner particles are produced in a separate lot, fine powder is removed by classification operation (such as cyclone, decanter, and centrifugal separation in the liquid). Classification may be performed after the toner is obtained as a powder after drying, but it is suitable in terms of efficiency to be performed in a liquid. The fine powder removed by the classification operation is preferably less than 3 μm. The fine powder can be returned to the aqueous medium and used to form toner particles.

Further, the relationship between the volume average particle diameter A of the toner having a predetermined particle diameter used as the toner classified by the classification operation described above and the volume average particle diameter B of the fine powder of the toner fine powder is as follows:
0.1 × A ≦ B ≦ 0.9 × A
It is preferable to satisfy. In the case of B> 0.9 × A, there is a problem in productivity that the toner yield of a predetermined particle diameter is reduced when the toner particles are produced in another lot. Further, in the case of B <0.1 × A, the volume average particle size is recovered as a bag fine powder, and the amount obtained by the classification operation is small, resulting in a problem of poor production efficiency.

(Coloring agent)
As the colorant of the toner of this embodiment, all 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, 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, Red Tan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Faisa Red, Lachlor Ortho Nitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carnmin BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX , Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Tolujing 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, oil red, quinacridone , Pyrazolone red, polyazo red, chrome vermilion, benzidine orange, perinone orange, oil orange, cobalt blue, cerulean blue, alkali blue rake, peacock blue rake, Victoria blue rake, 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, 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, ritbon, and mixtures thereof can be used. The content of the colorant is usually 1% to 15% by weight, preferably 3% to 10% by weight, as the content in the toner base of this embodiment.

  The colorant used in this embodiment can also be used as a master batch combined with a resin. As a binder resin kneaded together with the production of the masterbatch or the masterbatch, for example, styrene such as polystyrene, poly p-chlorostyrene, polyvinyltoluene, and the like in addition to the above-mentioned urea-modified polyester resin and non-reactive polyester resin, and its Substitute polymer, and 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, styrene-butyl methacrylate Copolymer, styrene -Methyl chloromethacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinylmethylketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene- Styrenic copolymers such as maleic acid copolymer and styrene-maleic acid ester copolymer, and 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 Can be used alone or in combination.

  The masterbatch of this embodiment can be obtained by mixing and kneading the masterbatch resin and the colorant under high shearing force. At this time, an organic solvent can be used to enhance the interaction between the colorant and the resin. In addition, a so-called flushing method called an aqueous paste containing water of a colorant is mixed and kneaded together with a resin and an organic solvent, and the colorant is transferred to the resin side to remove moisture and the organic solvent component. it can. According to this method, since the wet cake of the colorant can be used as it is, it does not need to be dried and is preferably used.

  For mixing and kneading, a high shearing dispersion device such as a three-roll mill is preferably used. Moreover, although a coloring agent or a masterbatch can be melt | dissolved or disperse | distributed in the above-mentioned organic solvent phase, it is not limited to this.

(Release agent)
In addition, the toner of the exemplary embodiment can contain a wax as a release agent together with the toner binder and the colorant. As the wax of the present embodiment, known waxes can be used, for example, polyolefin wax (such as polyethylene wax and polypropylene wax), long chain hydrocarbon (such as paraffin wax and sasol wax), and carbonyl group-containing Wax etc. are mentioned. Of these, carbonyl group-containing waxes are preferred. Examples of the carbonyl group-containing wax include polyalkanoic acid esters (carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18. -Octadecanediol distearate, etc.), polyalkanol esters (such as trimellitic trimellitic acid and distearyl maleate), polyalkanoic acid amides (such as ethylenediamine dibehenylamide), polyalkylamides (such as trimellitic acid tristearylamide) , And dialkyl ketones (such as distearyl ketone). Among these carbonyl group-containing waxes, polyalkanoic acid esters are preferred.

  The melting point of the wax of this embodiment is usually 40 ° C. or higher and 160 ° C. or lower, preferably 50 ° C. or higher and 120 ° C. or lower, more preferably 60 ° C. or higher and 90 ° C. or lower. A wax having a melting point of less than 40 ° C. adversely affects the heat resistant storage stability. In addition, waxes exceeding 160 ° C. tend to cause cold offset when fixing at low temperatures.

  The melt viscosity of the wax is preferably 5 cps or more and 1000 cps or less, more preferably 10 cps or more and 100 cps or less, as a measured value at a temperature 20 ° C. higher than the melting point. Waxes exceeding 1000 cps have poor effects for improving hot offset resistance and low-temperature fixability.

  Further, the amount of the wax used as the release agent is usually 0 to 40% by weight, preferably 3 to 30% by weight as the content in the toner base. The wax can be dissolved or dispersed in the organic solvent phase described above, but is not limited thereto.

(Charge control agent)
The toner of the exemplary embodiment may contain a charge control agent as necessary. As the charge control agent, all known ones can be used. For example, nigrosine dye, triphenylmethane dye, chromium-containing metal complex dye, molybdate chelate pigment, rhodamine dye, alkoxy amine, quaternary Examples include ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus simple substances or compounds, tungsten simple substances or compounds, fluorine-based activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives. Specifically, Bontron 03 of nigrosine dye, Bontron P-51 of quaternary ammonium salt, Bontron S-34 of metal-containing azo dye, E-82 of oxynaphthoic acid metal complex, E of salicylic acid metal complex -84, phenolic condensate E-89 (above, manufactured by Orient Chemical Co., Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP 1415 (above, manufactured by Hodogaya Chemical Co., Ltd.), quaternary Copy charge PSY VP 2038 of 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 (manufactured by Nippon Carlit), copper phthalocyanine, perylene, quinaclide , Azo pigments, as well as sulfonate group, a carboxyl group, and polymer compounds having a functional group such as quaternary ammonium salts.

  The amount of the charge control agent used in this embodiment is uniquely determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner manufacturing method including the dispersion method. Although it is not a thing, Preferably it is used in 0.1 to 10 weight part with respect to 100 weight part of binder resin. The range of 0.2 parts by weight or more and 5 parts by weight or less is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, so the effect of the main charge control agent is reduced, the electrostatic attractive force with the developing roller is increased, the developer fluidity is reduced, and the image density is increased. Cause a decline.

  These charge control agents can be dissolved and dispersed after being melt-kneaded together with the masterbatch and the resin, and may be added when directly dissolving or dispersing in the organic solvent. It is preferable to immobilize.

(Toner particle adjustment)
The toner of the exemplary embodiment can be manufactured by the following method, but is not limited thereto.

(Toner production method in aqueous medium)
The aqueous medium phase used in the present embodiment is used by adding resin fine particles and fine powder removed in the classification step when toner particles are produced in a different lot in advance. In the present embodiment, the fine powder obtained as described above is added again to the aqueous medium. At this time, the fine powder is preferably contained in an amount of 20 parts by weight or less based on 100 parts by weight of the aqueous medium. More preferably, the fine powder is 10 parts by weight or less with respect to 100 parts by weight of the aqueous medium. When the fine powder is contained in an amount of more than 20 parts by weight with respect to 100 parts by weight of the aqueous medium, when the toner particles are formed, the particles become coarse, the particle size distribution becomes broad, and the toner fixing lower limit temperature is increased. Increases, resulting in a problem that the low-temperature fixability deteriorates.

  The water used for the aqueous medium phase may be water alone, or a solvent miscible with water may be used in combination. Examples of miscible solvents include alcohols (such as methanol, isopropanol, and ethylene glycol), dimethylformamide, tetrahydrofuran, cellosolves (such as methyl cellosolve), and lower ketones (such as acetone and methyl ethyl ketone).

(Dispersion and reaction of organic solvent phase)
As described above, the toner particles are obtained by dispersing the organic solvent phase containing the polyester prepolymer (A) together with the amines (B) in the aqueous medium phase and extending and / or crosslinking in the aqueous medium phase. It is formed through a step of forming a urea-modified polyester. As a method for stably forming a dispersion comprising a polyester prepolymer (A) in an aqueous phase, a toner raw material composition comprising a polyester prepolymer (A) dissolved or dispersed in an organic solvent in an aqueous phase is used. In addition, a method of dispersing by shearing force may be mentioned. Polyester prepolymer (A) dissolved or dispersed in an organic solvent, and other toner compositions (hereinafter referred to as toner raw materials), a colorant, a colorant masterbatch, a release agent, a charge control agent, and a modified agent The polyester resin or the like may be mixed when the dispersion is formed in the aqueous phase, but after the toner raw material is mixed in advance and dissolved or dispersed in an organic solvent, the mixture is added to the aqueous phase and dispersed. Is more preferable. In this embodiment, other toner materials such as a colorant, a release agent, and a charge control agent do not necessarily have to be mixed when forming particles in an aqueous phase, and are added after the particles are formed. May be. For example, it is possible to add a colorant by a known dyeing method after forming particles that do not contain a colorant.

  The dispersion method is not particularly limited, and known methods such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied. In order to make the particle diameter of the dispersion 2 to 20 μm, it is preferable to use a high-speed shearing method. When a high-speed shearing disperser is used, the number of rotations is not particularly limited, but is usually 1000 rpm / min to 30000 rpm / min, preferably 5000 rpm / min to 20000 rpm / min. The dispersion time is not particularly limited, but in the case of a batch system, it is usually 0.1 to 5 minutes. The temperature at the time of dispersion is usually 0 ° C. or higher and 150 ° C. or lower, preferably 40 ° C. or higher and 98 ° C. or lower under pressure. High temperature conditions are preferred in that the dispersion of the polyester prepolymer (A) has a low viscosity and is easy to disperse.

  The usage-amount of the aqueous medium with respect to 100 mass parts of solid components contained in the organic solvent phase of the polyester prepolymer (A) is usually 50 parts by mass or more and 2000 parts by mass or less, preferably 100 parts by mass or more and 1000 parts by mass or less. . If the amount is less than 50 parts by weight, the dispersion state of the toner composition is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 20000 parts by weight, it is not economical.

  Moreover, a dispersing agent can also be used as needed. It is preferable to use a dispersant because the particle size distribution becomes sharp and the dispersion is stable.

  Examples of the dispersant for emulsifying or dispersing the organic solvent phase containing the polyester prepolymer (A) include anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, and alkylamines. Salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazoline, alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts, alkylisoquinolinium salts, benzethonium chloride, etc. Nonionic surfactants such as quaternary ammonium salt type cationic surfactants, fatty acid amide derivatives, and polyhydric alcohol derivatives (eg, alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine) And N- alkyl -N, amphoteric surfactants such as N- dimethyl ammonium betaine) and the like.

Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Preferred anionic surfactants having a fluoroalkyl group include fluoroalkylcarboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [omega-fluoroalkyl (C _{6 to} C6 C ₁₁₎ oxy] -1-alkyl _{(C 3} to _{C 4)} sulfonate, sodium 3- [omega - fluoroalkanoyl _{(C 6} to _C 8)-N-ethylamino] -1-propane sulfonate, fluoroalkyl (C _{11 to} C ₂₀ ) carboxylic acid and metal salt, perfluoroalkylcarboxylic acid (C _{7 to} C ₁₃ ) and metal salt thereof, perfluoroalkyl (C _{4 to} C ₁₂ ) sulfonic acid and metal salt thereof, perfluorooctane Sulfonic acid diethanolamide, N-propyl- - (2-hydroxyethyl) perfluorooctane sulfonamide, perfluoroalkyl _{(C 6} to _{C 10)} sulfonamide propyl trimethyl ammonium salts, perfluoroalkyl _{(C 6} to _C 10)-N-ethylsulfonyl glycine salts, and Monopa And fluoroalkyl (C _{6 to} C ₁₆ ) ethyl phosphate. As trade names, Surflon S-111, S-112, S-113 (above, manufactured by Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (above, manufactured by Sumitomo 3M), Unidyne DS-101, DS-102 (above, manufactured by Daikin Industries, Ltd.), MegaFuck F-l0, F-120, F-113, F-191, F-812, F-833 (above, manufactured by Dainippon Ink, Inc.) ), Xtop EF-102, EF-103, EF-104, EF-105, EF-112, EF-123A, EF-123B, EF-306A, EF-501, EF-201, EF-204 (above, Tochem Products, Inc.), Footgent F-100, and F150 (above, Neos).

In addition, as the cationic surfactant, aliphatic quaternary ammonium such as aliphatic primary, secondary, and secondary amine acids having a fluoroalkyl group, and perfluoroalkyl (C _{6 to} C ₁₀ ) sulfonamidopropyltrimethylammonium salt. Salts, benzalkonium salts, benzethonium chloride, pyridinium salts, and imidazolinium salts. Product names include Surflon S-121 (above, manufactured by Asahi Glass Co., Ltd.), Florard FC-135 (above, made by Sumitomo 3M), Unidyne DS-202 (above, made by Daikin Industries), MegaFuck F-150, F -824 (manufactured by Dainippon Ink Co., Ltd.), Xtop EF-132 (manufactured by Tochem Products Co., Ltd.), and footent F-300 (manufactured by Neos Co., Ltd.).

  As an inorganic compound dispersant that is hardly soluble in water, tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, hydroxyapatite, and the like can also be used.

  Further, the dispersed droplets may be stabilized by a polymer protective colloid. Examples of polymeric protective colloids include acrylic acids, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid, maleic anhydride, and other acids, and (Meth) acrylic monomers containing hydroxyl groups (for example, β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate) , Γ-hydroxypropyl methacrylate, 3-chloro-2-hydroxypropyl acrylate, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerin Monomethacrylic acid esters, N-methylol acrylamide, N-methylol methacrylamide, etc.), and ethers with vinyl alcohol or vinyl alcohol (eg, vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, etc.) , And esters of compounds containing vinyl alcohol and carboxyl groups (eg, pinyl acetate, pinyl propionate, vinyl butyrate, etc.), and acrylamide, methacrylamide, and diacetone acrylamide or their methylol compounds, and Acid chlorides such as acrylic acid chloride and methacrylic acid chloride, and nitrogen atoms such as pinylviridine, vinylpyrrolidone, vinylimidazole, and ethyleneimine, or heterocyclic rings thereof. Homopolymers or copolymers such as polyoxyethylene, polyoxypropylene, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenol Polyoxyethylenes such as enil ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, and polyoxyethylene nonyl phenyl ester, and celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used. .

  In addition, when using a substance that is soluble in an acid or alkali such as calcium phosphate as a dispersion stabilizer, the calcium phosphate is removed from the fine particles by a method such as washing with water after dissolving the calcium phosphate with an acid such as hydrochloric acid. . In addition, it can also be removed by an operation such as enzymatic degradation. When a dispersant is used, the dispersant can remain on the surface of the toner particles, but it is preferable from the charged surface of the toner that the dispersant is washed and removed after the elongation and / or crosslinking reaction.

  The elongation and / or crosslinking reaction time is determined by the reactivity of the isocyanate group structure of the prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 hours. It is 24 hours or less. The reaction temperature is usually 0 ° C. or higher and 150 ° C. or lower, preferably 40 ° C. or higher and 98 ° C. or lower. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.

  In order to remove the organic solvent from the obtained emulsified dispersion, a method of gradually raising the temperature of the entire system and completely evaporating and removing the organic solvent in the droplets can be used. Alternatively, the emulsified dispersion can be sprayed in a dry atmosphere to completely remove the water-insoluble organic solvent in the droplets to form toner fine particles, and the aqueous dispersant can be removed by evaporation together. As the dry atmosphere in which the emulsified dispersion is sprayed, a gas obtained by heating air, nitrogen, carbon dioxide gas, combustion gas, etc., in particular, various air streams heated to a temperature higher than the boiling point of the highest boiling solvent used are generally used. It is done. Sufficient quality can be ensured by short-time processing such as spray dryer, belt dryer, and rotary kiln.

  When the particle size distribution at the time of emulsification dispersion is wide and washing and drying are performed while maintaining the particle size distribution, the particle size distribution can be adjusted by classifying the particles into a desired particle size distribution. In the classification operation, the fine powder portion can be removed in the liquid by a cyclone, a decanter, a centrifugal separator, or the like. Of course, the classification operation may be performed after obtaining the powder as a powder after drying, but it is preferably performed in a liquid in terms of efficiency. In the present embodiment, the recovered unnecessary fine powder can be returned to the aqueous medium and used for the formation of particles. At that time, the fine powder may be in a wet state. It is preferable to remove the used dispersant as much as possible from the obtained dispersion. The removal of the dispersant is preferably performed simultaneously with the classification operation described above.

  The obtained toner powder after drying together with the above-mentioned releasing agent fine particles, the above-mentioned charge control fine particles, the fluidizing agent fine particles as external additives described below, and the above-mentioned different color particles such as the above-mentioned colorant fine particles. By mixing or applying a mechanical impact force to the mixed powder, it can be fixed or fused on the surface of the toner particles to prevent the detachment of different particles from the surface of the resulting composite particles. it can.

  As specific means, a method of applying an impact force to the mixture with blades rotating at high speed, a method of injecting the mixture into a high-speed air stream, accelerating it, and colliding particles or composite particles with an appropriate collision plate, etc. There is. The equipment that can be used in this method includes an on-mill (made by Hosokawa Micron Corporation), an I-type mill (made by Nippon Pneumatic Co., Ltd.), and a pulverization air pressure lowered, and a hybridization system (Nara Machinery Co., Ltd.). Product), kryptron system (manufactured by Kawasaki Heavy Industries, Ltd.), and automatic mortar.

(External additive)
As an external additive for assisting fluidity, developability, and chargeability of the colored particles obtained in the present embodiment, inorganic fine particles can be preferably used. The primary particle diameter of the inorganic fine particles is preferably 5 nm or more and 2 μm or less, and more preferably 5 nm or more and 0.5 μm or less. The specific surface area by the BET method is preferably not more than ^{20 m} 2 / g or more 500m ² / g. The use ratio of the inorganic fine particles is preferably 0.01% by weight or more and 5% by weight or less of the toner, and more preferably 0.01% by weight or more and 2.0% by weight or less. When the proportion of the inorganic fine particles used is greater than 5% by weight of the toner, the two-component developer causes the toner to fuse to the surface of the carrier during long-term agitation in the developing device, thereby reducing the charging ability of the carrier. Further, when this toner is used as a one-component developer, it is easy to cause toner filming on the developing roller and toner fusion to a member such as a blade for thinning the toner.

  Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, Examples thereof include diatomaceous earth, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. In addition, molecular system fine particles, for example, polycondensation systems such as polystyrene, methacrylic acid ester, acrylic acid ester copolymer, silicon, benzoguanamine, and nylon obtained by soap-free emulsion polymerization, suspension polymerization, and dispersion polymerization, The polymer particle by a thermosetting resin is mentioned.

  Such an external additive can improve hydrophobicity by performing surface treatment in advance, and can prevent deterioration of flow characteristics and charging characteristics even under high humidity. For example, silane coupling agents, silylating agents, silane coupling agents having an alkyl fluoride group, organic titanate coupling agents, aluminum coupling agents, silicone oil, and modified silicone oils are preferred surface treatment agents. Can be mentioned.

  On the other hand, as a cleaning property improver for removing the developer after transfer remaining on the photosensitive member and the primary transfer medium, for example, fatty acid metal salts such as zinc stearate, calcium stearate, stearic acid, for example, polymethyl methacrylate fine particles And polymer fine particles produced by soap-free emulsion polymerization such as polystyrene fine particles. The polymer fine particles preferably have a relatively narrow particle size distribution and a volume average particle size of 0.01 μm to 1 μm.

(Toner circularity and circularity distribution)
It is important that the toner of the present exemplary embodiment has a specific shape and shape distribution. With an irregularly shaped toner having an average circularity of less than 0.90 that is too far from the spherical shape, satisfactory transferability and high-quality images free from dust cannot be obtained.

  As a method for measuring the circularity, an optical detection band method is used in which a suspension containing toner particles 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. . A value obtained by dividing the perimeter of an equivalent circle having the same projected area obtained by this method by the perimeter of the actual particle is defined as the average circularity.

  When the average circularity is 0.90 or more and 0.98 or less, it is effective to form a high-definition image having a reproducibility with an appropriate density. More preferably, toner particles having an average circularity of 0.95 or more and 0.97 or less and a circularity of less than 0.94 are 15% or less. When the average circularity is 0.98 or more, in a system that employs blade cleaning or the like, a cleaning failure occurs on the photosensitive member or the transfer belt, causing stain on the image. In development and transfer with a low image area ratio, there is little toner remaining after transfer, and cleaning defects do not become a problem. However, when the image area ratio is high, such as a color photographic image, untransferred image-formed toner may be generated on the photoreceptor as a transfer residual toner due to poor paper feed, etc. Will occur. In addition, the charging roller that contacts and charges the photosensitive member is contaminated, and the original charging ability cannot be exhibited.

(Measurement of toner circularity)
A method for measuring the circularity of the toner using a flow particle image analyzer will be described below.

  The toner, toner particles, and external additives can be measured using a flow particle image analyzer FPIA-2000 manufactured by Toa Medical Electronics Co., Ltd., for example.

The measurement is performed by removing fine dust through a filter, and as a result, in ^10-3 water of 10 ⁻³ cm ³ of water having a measurement range (for example, an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm) of 20 particles or less. Add a few drops of an anionic surfactant (preferably, Contaminone N manufactured by Wako Pure Chemical Industries, Ltd.). 5 mg of a measurement sample was added to this, and dispersion treatment was performed for 1 minute under the conditions of 20 kHz and 50 W / 10 cm ^{3 with} an ultrasonic dispersing device STM UH-50. Particle size distribution of particles having a circle-equivalent diameter of 0.60 μm or more and less than 159.21 μm using a sample dispersion having a concentration of 4000 to 8000/10 ⁻³ cm ³ (for particles in the measurement circle-equivalent diameter range). Measure.

  The sample dispersion liquid is passed through a flow path (expanded along the flow direction) of a flat and flat transparent flow cell (thickness: about 200 μm). In order to form an optical path that passes across the thickness of the flow cell, the strobe and the CCD camera are mounted so as to be opposite to each other with respect to the flow cell. While the sample dispersion is flowing, strobe light is irradiated at 1/30 second intervals to obtain an image of particles flowing through the flow cell. As a result, each particle is photographed as a two-dimensional image having a certain range parallel to the flow cell. From the area of the two-dimensional image of each particle, the diameter of a circle having the same area is calculated as the equivalent circle diameter.

  In about 1 minute, the equivalent circle diameter of 1200 or more particles is measured, and the number based on the equivalent circle diameter distribution and the ratio (number%) of particles having the prescribed equivalent circle diameter are measured. The result (frequency% and cumulative%) is obtained by dividing the range of 0.06 to 400 μm into 226 channels (divided into 30 channels per octave). In actual measurement, particles are measured in the range where the equivalent circle diameter is 0.60 μm or more and less than 159.21 μm.

(Toner particle size)
The toner according to the exemplary embodiment preferably has a volume average particle diameter (Dv) of 3 μm to 8 μm, and more preferably 4 μm to 7 μm. The ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) is preferably 1.25 or less, more preferably 1.10 or more and 1.20 or less. is there.

Here, the volume average particle diameter (Dv) is
Dv = [Σ (nD3) / Σn] / 3 where n is the number of particles and D is the particle diameter.
Is defined. In this embodiment, by setting the value of Dv / Dn within the above-mentioned range, it is excellent in all of heat-resistant storage stability, low-temperature fixability, and hot-offset resistance, and particularly when used in a full-color copying machine or the like. A toner having excellent gloss can be obtained. Furthermore, in a two-component developer, even if a long-term balance of toner is performed, fluctuations in the toner particle diameter in the developer are reduced, and good and stable developability can be achieved even with long-term stirring in the developing device. can get. Further, even when used as a one-component developer, even if the balance of the toner is performed, the fluctuation of the toner particle diameter is reduced, the filming of the toner on the developing roller, and the thinning of the toner are performed. The toner is not fused to a member such as a blade, and good and stable developability and images can be obtained even when the developing device is used (stirred) for a long time.

  In general, it is said that the smaller the particle size of the toner, the more advantageous it is to obtain a high-resolution and high-quality image, but it is disadvantageous for transferability and cleaning property. is there. Further, when the volume average particle diameter (Dv) is smaller than 3 μm, in the case of a two-component developer, the toner is fused to the surface of the carrier during a long period of stirring in the developing device, and the charging ability of the carrier is lowered. Further, when this toner is used as a one-component developer, it is easy to cause toner filming on the developing roller and toner fusion to a member such as a blade for thinning the toner.

  Conversely, when the volume average particle diameter (Dv) is larger than 8 μm, it becomes difficult to obtain a high-resolution and high-quality image, and the toner particle diameter when the balance of the toner in the developer is performed. In many cases, fluctuations of The same problem occurs when the volume average particle diameter / number average particle diameter (Dv / Dn) is too large. Further, if the volume average particle diameter / number average particle diameter (Dv / Dn) is too small, there are preferable aspects from the viewpoint of stabilizing the behavior of the toner and equalizing the charge amount, but the toner becomes insufficiently charged. The case is seen. In addition, the cleaning property may be deteriorated.

(Measurement of toner particle size)
The volume average particle size / number average particle size (Dv / Dn) is measured using the particle size measuring device “Coulter Counter TAII” manufactured by Coulter Electronics Co., Ltd. and the volume average particle size (Dv) measured with an aperture diameter of 100 μm and the number average. It is automatically measured by the value of particle diameter (Dn).

  First, 0.1 to 5 ml of a surfactant (preferably alkyl benzene sulfonate) is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution. Here, the electrolytic solution is prepared by preparing a 1% NaCl aqueous solution using primary sodium chloride. For example, ISOTON-II (manufactured by Coulter) can be used. Here, 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the volume and number of toner particles or toner are measured with the above-described measuring apparatus using a 100 μm aperture as an aperture. The volume distribution and the number distribution are calculated. From the obtained distribution, the weight average particle diameter and the number average particle diameter of the toner can be obtained.

  The channels are 2.00 μm or more and less than 2.52 μm, 2.52 μm or more and less than 3.17 μm, 3.17 μm or more and less than 4.00 μm, 4.00 μm or more and less than 5.04 μm, 5.04 μm or more and less than 6.35 μm, 6 .35 μm to less than 8.00 μm, 8.00 μm to less than 10.08 μm, 10.08 μm to less than 12.70 μm, 12.70 μm to less than 16.00 μm, 16.00 μm to less than 20.20 μm, 20.20 μm to less than 25. Using 13 channels of less than 40 μm, 25.40 μm or more and less than 32.00 μm, and 32.00 μm or more and less than 40.30 μm, particles having a particle size of 2.00 μm or more and less than 40.30 μm are targeted.

(Measurement of peak molecular weight of toner by GPC)
The molecular weight according to the present embodiment is measured by a GPC-8220 GPC (manufactured by Tosoh Corp.) measuring device by GPC (gel permeation chromatography). A column (TSO-gel SuperHZM-H 15 cm column manufactured by Tosoh Corporation was used in triplicate) was stabilized in a heat chamber at 40 ° C., and tetrahydrofuran as a solvent was supplied at a flow rate of 0.35 ml / min to the column at this temperature. And the sample solution prepared to 0.15% by weight as the sample concentration is injected by injecting 0.4 ml. In measuring the molecular weight of the sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithmic value of the calibration curve prepared from several monodisperse polystyrene standard samples and the number of counts. Examples of standard polystyrene samples for preparing calibration curves include Showdex STANDARD Std. No S-7300, S-210, S-390, S-875, S-1980, S-10.9, S-629, S-3.0, and S-0.580, and at least about 10 points The number average molecular weight (Mn) and the weight average molecular weight (Mw) of the toner are calculated using a molecular weight calibration curve prepared from the standard polystyrene sample. A refractive index detector is used as the detector.

(Acid value and hydroxyl value of toner)
The acid value of the toner is usually 1 KOH mg / g or more and 40 KOH mg / g or less, preferably 5 KOH mg / g or more and 30 KOH mg / g or less, more preferably 15 KOH mg / g or more and 28 KOH mg / g or less. By giving a predetermined acid value, the toner tends to be negatively charged, the affinity with paper at the time of fixing is increased, and the fixing power can be strengthened.

  The hydroxyl value of the toner is usually preferably 5 KOH mg / g or more, more preferably 10 KOH mg / g or more and 120 KOH mg / g or less, and particularly preferably 20 KOH mg / g or more and 80 KOH mg / g or less. When the hydroxyl value of the toner is less than 5 KOHmg / g, it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

(Method for measuring acid value and hydroxyl value of toner)
The method for measuring the acid value of the toner of the present embodiment is measured under the following conditions based on the measurement method described in JIS K0070-1992. However, when the toner sample does not dissolve, a solvent such as dioxane or tetrahydrofuran is used as the solvent. The sample toner 0.5 g (0.3 g for ethyl acetate soluble component) is added to 120 ml of toluene and dissolved by stirring at 23 ° C. for about 10 hours. Furthermore, 30 ml of ethanol is added to prepare a sample solution. However, if the sample does not dissolve, a solvent such as dioxane or tetrahydrofuran is used as the solvent. The obtained measurement sample was measured at a measurement temperature of 23 ° C. using a measurement system in which an electrode DG113-SC (manufactured by METTLER TOLEDO) was attached to a potentiometric automatic titrator DL-53 Titrator (manufactured by METTLER TOLEDO). taking measurement. Further, a mixed solvent of 120 ml of toluene and 30 ml of ethanol is used for calibration of the above-described apparatus. Analysis software LabX Light Version 1.0 is used for analysis of measurement data. The acidity can be calculated by the above-described measuring apparatus and analysis software. Specifically, the acidity is calculated as follows. Titrate with a pre-standardized N / 10 caustic potash / alcohol solution, and calculate the acid value from the consumption of the alcohol potash solution by the following formula.

Acid value = KOH (ml) x N x 56.1 / sample weight (where N is a factor of N / 10 KOH)
The method for measuring the hydroxyl value of the toner of the present embodiment is performed under the following conditions in accordance with the measurement method described in JIS K0070-1966.

  0.5 g of the sample toner is precisely weighed into a 100 ml volumetric flask, and 5 ml of acetylating reagent is added thereto. Then, it is immersed in a 100 ± 5 ° C. warm bath and heated. After 1 to 2 hours, the flask is removed from the warm bath, allowed to cool, water is added and shaken to decompose acetic anhydride. Further, in order to complete the decomposition, the flask is again heated in a bath for 10 minutes or more and allowed to cool, and then the flask wall is thoroughly washed with an organic solvent. The liquid thus obtained was measured at a measurement temperature of 23 using a measurement system in which an electrode DG113-SC (manufactured by METTLER TOLEDO) was mounted on an automatic potentiometric titrator DL-53 Titrator (manufactured by METTLER TOLEDO). The hydroxyl value is measured by potentiometric titration with N / 2 potassium hydroxide ethyl alcohol solution at ° C.

(Developer)
When the toner of this embodiment is used for a two-component developer, it may be used by mixing with a magnetic carrier. In this case, the content ratio of the carrier and the toner in the developer is preferably 1 part by weight or more and 10 parts by weight or less, and more preferably 3 parts by weight or more and 9 parts by weight or less with respect to 100 parts by weight of the carrier. As the magnetic carrier, conventionally known ones such as iron powder, ferrite powder, magnetite powder, and magnetic resin carrier having a particle diameter of about 20 to 200 μm can be used. Examples of the coating material include amino resins such as urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin. Polyvinyl resins and polyvinylidene resins such as acrylic resins, polymethyl methacrylate resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins, polystyrene resins, and styrene acrylic copolymer resins. , And polyester resins such as halogenated olefin resins such as polyvinyl chloride, polyethylene terephthalate resins, and polybutylene terephthalate resins, polycarbonate resins, polyethylene resins, polyvinyl fluoride resins, and polyfluorides. Vinylidene resin, polytrifluoroethylene resin, polyhexafluoropropylene resin, and copolymer of vinylidene fluoride and acrylic monomer, Each time, a copolymer of vinylidene fluoride and vinyl fluoride, and, fluoro terpolymers such as terpolymer of tetrafluoroethylene, and vinylidene fluoride non-fluorinated monomer, and, a silicon resin can be used. Moreover, you may make conductive powder etc. contain in coating resin as needed.

  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 diameter of 1 μm or less. When the average particle diameter is larger than 1 μm, it becomes difficult to control electric resistance. In addition, the toner of the present exemplary embodiment can be used as a one-component magnetic toner or a nonmagnetic toner that does not use a carrier.

(Process cartridge)
The process cartridge of the present embodiment 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 containing toner. And at least developing means for forming a visible image, and further having other means appropriately selected as necessary.

  FIG. 1 is a configuration diagram of a process cartridge according to an embodiment of the present invention.

  Referring to FIG. 1, the process cartridge 99 is roughly divided into a photosensitive member 10 that is an electrostatic latent image carrier, a charger 21 that is an electrostatic latent image forming unit, and an exposure apparatus that is also an electrostatic latent image forming unit. 30, a developing device 40 as a developing unit, a cleaning device 60 as a cleaning unit, a neutralizing lamp 70 as a neutralizing unit, and a transfer roller 80 as a transferring unit.

  Each component of the process cartridge 99 described above will be described in detail in the section of the image forming apparatus described below.

  The process cartridge according to this embodiment can be freely provided in various electrophotographic apparatuses and the like, and is preferably provided detachably in the image forming apparatus according to this embodiment described below. Further, being detachable enables maintenance of the image forming apparatus described below.

(Image forming device)
The image forming apparatus according to the present embodiment 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 other units appropriately selected as necessary. For example, it comprises a static elimination means, a cleaning means, a recycling means, and a control means.

  The material, shape, structure, size, etc. of the electrostatic latent image carrier, also referred to as a photoreceptor, are not particularly limited, and can be appropriately selected from known ones. A preferable example of the shape of the electrostatic latent image carrier is a drum shape. Examples of the material for the electrostatic latent image carrier include inorganic photoreceptors such as amorphous silicon and selenium, and organic photoreceptors such as polysilane and phthalopolymethine. Among these, amorphous silicon is preferable because of its long life. The photoconductor made of amorphous silicon will be described in detail below.

  The formation of the electrostatic latent image can be performed by uniformly charging the surface of the above-described electrostatic latent image carrier and then performing imagewise exposure by the above-described electrostatic latent image forming unit.

  The electrostatic latent image forming means includes, for example, at least charging means for uniformly charging the surface of the above-described electrostatic latent image carrier and exposure means for exposing the surface of the electrostatic latent image carrier imagewise. .

  Charging can be performed by applying a voltage to the surface of the electrostatic latent image carrier using a charger.

  The charging means is not particularly limited and may be appropriately selected according to the purpose. For example, a known contact charging provided with a conductive or semiconductive roll, brush, film, rubber blade, etc. And non-contact chargers using corona discharge such as corotron and scorotron.

  In the present embodiment, it is preferable to use a charging unit that directly contacts the surface of the electrostatic latent image carrier and applies a voltage to uniformly charge the surface of the electrostatic latent image carrier. Use of such a charging means is preferable in that generation of ozone in the apparatus can be suppressed.

  The exposure can be performed by exposing the surface of the electrostatic latent image carrier imagewise using the above-described exposure device.

  The exposure device means is not particularly limited as long as the surface of the electrostatic latent image carrier charged by the above-described charger can be exposed like an image to be formed, and is appropriately selected according to the purpose. Examples thereof include 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.

  In the present embodiment, an optical backside system that performs imagewise exposure from the backside of the electrostatic latent image carrier may be employed.

  Next, the developing unit will be described.

  The developing means develops the above-described electrostatic latent image using the developer containing the toner of the present embodiment to form a visible image.

  The visible image can be formed by developing the electrostatic latent image using a developer containing the toner of the present embodiment by a developing unit.

  The developing means is not particularly limited as long as it can be developed using the developer containing the toner of the present embodiment, and can be appropriately selected from known ones. For example, a developer that contains at least a developer that contains the toner of the present embodiment and that can apply the developer to the electrostatic latent image in a contact or non-contact manner is preferably used. A developing device provided with the toner container of the present embodiment is more preferable.

  The developing means may be a single color developer or a multicolor developer. For example, it is preferable to use a stirrer for charging a developer containing toner by frictional stirring and a rotatable magnet roller.

  In the developing means, the toner and the carrier are mixed and agitated, and the toner is charged by the friction at that time, and is held on the surface of the rotating magnet roller in a raised state, thereby forming a magnetic brush. Since the magnet roller is disposed in the vicinity of the above-described electrostatic latent image carrier (photosensitive member), a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is statically absorbed by an electric attractive force. It moves to the surface of the electrostatic latent image carrier (photoconductor). As a result, the electrostatic latent image is developed with toner, and a visible image is formed with 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 embodiment, but the developer may be a one-component developer or a two-component developer. The toner contained in these developers is the toner of the present embodiment.

  Next, the transfer unit will be described.

  The transfer unit is a unit that transfers a visible image to a recording medium. The transfer unit preferably uses an intermediate transfer member, and after the primary transfer of the visible image onto the intermediate transfer member, the visible image is secondarily transferred onto the recording medium. Further, the transfer means uses a primary transfer means for forming a composite transfer image by transferring a visible image onto an intermediate transfer member using two or more colors, preferably full color toner, as a toner, and the composite transfer image as a recording medium. More preferable is a mode including a secondary transfer means for transferring the image on the top.

  The intermediate transfer member is not particularly limited and can be appropriately selected from known transfer members according to the purpose. For example, a transfer belt is preferably used.

  The primary transfer unit and the secondary transfer unit preferably include at least a transfer unit that peels and charges the visible image formed on the electrostatic latent image carrier (photoconductor) to the recording medium side. There may be one transfer means, or two or more transfer means.

  Examples of the transfer means include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.

  In addition, there is no restriction | limiting in particular as a recording medium, It can select suitably from well-known recording media (recording paper).

  The fixing means is means for fixing the visible image transferred to the recording medium by the fixing device, and may be performed each time the toner of each color is transferred to the recording medium, or the toners of each color are laminated. May be performed simultaneously at the same time.

  The fixing unit is not particularly limited and may be appropriately selected depending on the purpose. However, a known heating and pressing unit is preferable. Examples of the heating and pressing means include a combination of a heating roller and a pressure roller, and a combination of a heating roller, a pressure roller, and an endless belt.

  The heating in the heating and pressing means is usually preferably 80 ° C. or higher and 200 ° C. or lower.

  In this embodiment, for example, a known optical fixing device may be used together with or instead of the fixing step and the fixing unit depending on the purpose.

  In this embodiment, it is particularly preferable to use a surf fixing device as the fixing device. The surf fixing device will be described in detail below.

  The neutralizing unit is a unit that performs neutralization by applying a neutralizing bias to the electrostatic latent image carrier (photoconductor). The neutralizing means is not particularly limited as long as it can apply a neutralizing bias to the electrostatic latent image carrier, and can be appropriately selected from known neutralizers. For example, a static elimination lamp etc. are mentioned suitably.

  The cleaning means is means for removing the electrophotographic toner remaining on the electrostatic latent image carrier.

  The cleaning means is not particularly limited as long as it can remove the toner remaining on the electrostatic latent image carrier, and can be appropriately selected from known cleaners. For example, a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, a brush cleaner, a web cleaner, and the like are preferable.

  The recycling means is means for recycling the color toner for electrophotography removed by the above-described cleaning means to the developing means.

  There is no restriction | limiting in particular as a recycle means, A well-known conveyance means etc. are mentioned.

  The control means is a process for controlling the above-described steps, and can be suitably performed by the control means.

  The control means is not particularly limited as long as it can control the movement of each means described above, and can be appropriately selected according to the purpose. For example, devices such as a sequencer and a computer can be mentioned.

  One aspect of the image forming apparatus of this embodiment will be described.

  FIG. 2 is a configuration diagram (part 1) of the image forming apparatus according to the present embodiment.

  Referring to FIG. 2, an image forming apparatus 100A includes a photosensitive member 10 as an electrostatic latent image carrier, a charging roller 20 as a charging unit, an exposure device 30 as an exposure unit, a developing device 40 as a developing unit, and an intermediate unit. It comprises a transfer body 50, a cleaning device 60 as a cleaning means having a cleaning blade, and a static elimination lamp 70 as a 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 in contact with the photosensitive member 10 and the intermediate transfer member 50 in the rotation direction of the intermediate transfer member 50. 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 a developer carrying member, and a black developing unit 45K, a yellow developing unit 45Y, a magenta developing unit 45M, and a cyan developing unit 45C provided around the developing belt 41. 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.

  The surface layer material and the surface layer of the developing belt 41 prevent contamination of the photosensitive member by the elastic material, reduce surface friction resistance to the surface of the transfer belt and reduce the adhesion force of the toner, and provide cleaning properties and secondary transfer properties. What is needed is to be enhanced. For example, one type or two or more types such as polyurethane, polyester, and epoxy resin are used. In addition, a material that reduces surface energy and increases lubricity, for example, one or more powders or particles of fluororesin, fluorine compound, fluorocarbon, titanium dioxide, and silicon carbide, or a particle size Different types can be dispersed and used. In addition, a material that has a surface-energy reduced by forming a fluorine-rich layer on the surface by heat treatment, such as a fluorine-based rubber material, can be used.

  In the image forming apparatus 100A, for example, the charging roller 20 charges the photoreceptor 10 uniformly. The exposure device 30 performs imagewise exposure on the photoreceptor 10 to form an electrostatic latent image. The electrostatic latent image formed on the photoconductor 10 is developed by supplying toner from the developing device 40 to form a visible image (toner image). This 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 by the transfer roller 80. 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 removed by the charge eliminating lamp 70. Similarly, the residual toner on the intermediate transfer member 50 is removed by the cleaning device 90.

  Another aspect of the image forming apparatus of this embodiment will be described.

  FIG. 3 is a configuration diagram (part 2) of the image forming apparatus of the present embodiment.

  Referring to FIG. 3, the image forming apparatus 100B does not include the developing belt 41 unlike the image forming apparatus 100A shown in FIG. 2, and a black developing unit 45K, a yellow developing unit 45Y, Except that the magenta developing unit 45M and the cyan developing unit 45C are directly opposed to each other, the configuration is the same as that of the image forming apparatus 100A shown in FIG. In FIG. 3, the same reference numerals are assigned to the configurations described above, and detailed description thereof is omitted.

  Another aspect of the image forming apparatus of this embodiment will be described.

  FIG. 4 is a configuration diagram (part 3) of the image forming apparatus of the present embodiment, and FIG. 5 is a partial enlarged view of the configuration diagram (part 3) of the image forming apparatus of the present embodiment. FIG. 5 is an enlarged view of two of the image forming units shown in FIG.

  4 and 5, the tandem image forming apparatus 120 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 roller 14, the support roller 15, and the support roller 16, and can rotate clockwise in FIG. An intermediate transfer body cleaning device 17 for removing residual toner on the intermediate transfer body 50 is disposed in the vicinity of the support roller 15. The intermediate transfer member 50 stretched by the support roller 14 and the support roller 15 has four image forming units 18 of yellow, cyan, magenta, and black facing each other along the conveyance direction and tandem development. A container 120 is arranged. An exposure device 30 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 is disposed in the vicinity of the secondary transfer device 22 and the fixing device 25 in order to form an image on both sides of the transfer paper. ing.

  Next, formation of a full-color image (color copy) using the tandem developing device 120 will be described. The 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, and the automatic document feeder 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. A document (color image) is read and used as black, yellow, magenta, and cyan image information.

  Each image information of black, yellow, magenta, and cyan is stored in each image forming unit 18 (black image forming unit, yellow image forming unit, magenta image forming unit, and cyan image) in the tandem developing device 120. Each of the image forming units forms black, yellow, magenta, and cyan toner images. 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, as shown in FIG. (A black photoconductor 10K, a yellow photoconductor 10Y, a magenta photoconductor 10M, and a cyan photoconductor 10C), a charger 60 (reference numeral is shown in FIG. 5) for uniformly charging the photoconductor, An exposure device 30 that exposes the photosensitive member like an image corresponding to each color image based on the color image information (L in FIG. 5) and forms an electrostatic latent image corresponding to each color image on the photosensitive member; A developing unit 61 (reference numerals are shown in the figure) develops the latent image with each color toner (black toner, yellow toner, magenta toner, and cyan toner) to form a toner image with each color toner. And a transfer charger 62 for transferring the toner image onto the intermediate transfer member 50, a photoconductor cleaning device 63 as a cleaning means, and a static eliminator 64 as a static elimination means. Each monochrome image (black image, yellow image, magenta image, and cyan image) can be formed based on the color image information. The black image, the yellow image, the magenta image, and the cyan image formed in this manner are formed on the black photoconductor 10K on the intermediate transfer member 50 that is rotated by the support roller 14, the support roller 15, and the support roller 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). ) Then, a black image, a yellow image, a magenta image, and a 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 the recording paper from one of the paper feed cassettes 144 provided in multiple stages in the paper bank 143, and one sheet at a time by the separation roller 145. The paper 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 to stop. Alternatively, the recording roller 150 is rotated to feed out the 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 the recording paper is sent between the intermediate transfer member 50 and the secondary transfer device 22. Then, by transferring (secondary transfer) the composite color image (color transfer image) onto the recording paper by the secondary transfer device 22, the color image is transferred and formed on the recording paper. The residual toner on the intermediate transfer member 50 after image transfer is cleaned by the intermediate transfer member cleaning device 17.

  The 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 a combined color image (color transfer image) is recorded by heat and pressure. Fixed on paper. Thereafter, the recording paper is switched by the switching claw 55 and discharged by the discharge roller 56 and stacked on the paper discharge tray 57. Alternatively, the recording paper is switched by the switching claw 55 and reversed by the sheet reversing device 28 to be led to the transfer position again. After the image is also recorded 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 embodiment, since the toner of the present invention having excellent charging performance and surface properties is used, high image quality can be obtained efficiently.

(Amorphous silicon photoconductor)
As the electrophotographic photoreceptor used in the present embodiment, a conductive support is heated to 50 ° C. or higher and 400 ° C. or lower, and a vacuum deposition method, a sputtering method, an ion plating method, or thermal CVD is applied on the conductive support. An amorphous silicon photoconductor (hereinafter referred to as an a-Si type photoconductor) having a photoconductive layer made of a-Si can be used by a film forming method such as a CVD method, a photo CVD method, or a plasma CVD method. Among them, a plasma CVD method, that is, a method in which a source gas is decomposed by direct current, high frequency or microwave glow discharge to form an a-Si deposited film on a support is preferably used.

  The layer structure of the amorphous silicon photoconductor is, for example, as follows.

  FIG. 6 is a schematic configuration diagram for explaining the layer configuration of the amorphous silicon photoconductor of the present embodiment.

  Referring to FIG. 6A, the electrophotographic photoreceptor 600 is provided with a photoconductive layer 602 made of a-Si: H and having photoconductivity on a support 601.

  Referring to FIG. 6B, an electrophotographic photoreceptor 600 includes a photoconductive layer 602 made of a-Si: H and having photoconductivity, an amorphous silicon based surface layer 603, on a support 601. It is composed of

  Referring to FIG. 6C, the electrophotographic photoreceptor 600 includes a photoconductive layer 602 made of a-Si: H and having photoconductivity, an amorphous silicon-based surface layer 603, on a support 601. And an amorphous silicon based charge injection blocking layer 604.

  Referring to FIG. 6D, the electrophotographic photoreceptor 600 is provided with a photoconductive layer 602 on a support 601. The photoconductive layer 602 includes a charge generation layer 605 and a charge transport layer 606 made of a-Si: H, and an amorphous silicon-based surface layer 603 is provided thereon.

  The support 601 of the photoconductor 600 may be conductive or electrically insulating. Examples of the conductive support include metals such as Al, Cr, Mo, Au, In, Nb, Te, V, Ti, Pt, Pd, and Fe, and alloys of the above metals, such as stainless steel. . Also, at least the photosensitive layer-forming side of an electrically insulating support such as polyester, polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polystyrene, polyamide, or other synthetic resin film, sheet, glass, or ceramic. A support having a conductive surface can also be used.

  The shape of the support 601 can be a smooth or uneven cylindrical or plate-like shape, or an endless belt shape, and the thickness thereof is appropriately determined so that a desired photoreceptor for an image forming apparatus can be formed. However, when flexibility as a photoreceptor for an image forming apparatus is required, it can be made as thin as possible within a range in which the function as a support can be sufficiently exhibited. However, the support is usually 10 μm or more from the viewpoint of manufacturing and handling, such as mechanical strength.

  As shown in FIG. 6C, the amorphous silicon photoconductor 600 that can be used in this embodiment includes a conductive support 601 between the conductive support 601 and the photoconductive layer 602 as necessary. It is more effective to provide a charge injection blocking layer 604 that functions to block charge injection from the side. That is, the charge injection blocking layer 604 has a function of blocking charge injection from the support 601 side to the photoconductive layer 602 side when the photosensitive layer is subjected to a charging process with a certain polarity on its free surface. It has a so-called polarity dependency in which such a function is not exhibited when it is subjected to a charging process with a reverse polarity. In order to provide such a function, the charge injection blocking 604 layer contains a relatively large amount of atoms for controlling conductivity as compared with the photoconductive layer 602.

  The layer thickness of the charge injection blocking layer 604 is preferably 0.1 μm or more and 5 μm or less, more preferably 0.3 μm or more and 4 μm or less, and optimally 0 in view of obtaining desired electrophotographic characteristics and economic effects. It is desirable to be 5 μm or more and 3 μm or less.

  The photoconductive layer 602 is formed on the undercoat layer as necessary, and the layer thickness of the photoconductive layer 602 is appropriately determined as desired from the viewpoint of obtaining desired electrophotographic characteristics and economic effects. The thickness is preferably 1 μm to 100 μm, more preferably 20 μm to 50 μm, and most preferably 23 μm to 45 μm.

  The charge transport layer 606 is a layer mainly having a function of transporting charges when the photoconductive layer 602 is functionally separated. The charge transport layer 606 includes at least silicon atoms, carbon atoms, and fluorine atoms as constituent elements, and if necessary, a-SiC containing hydrogen atoms and oxygen atoms (or H, F, O instead of C). And has desired photoconductive properties, in particular, charge retention properties, charge generation properties, and charge transport properties. In the present embodiment, it is particularly preferable to contain an oxygen atom.

  The layer thickness of the charge transport layer 606 is appropriately determined as desired from the viewpoint of obtaining desired electrophotographic characteristics and economic effects. The charge transport layer is preferably 5 μm or more and 50 μm or less, more preferably 10 μm or more. It is desirable that the thickness be 40 μm or less, optimally 20 μm or more and 30 μm or less.

  The charge generation layer 605 is a layer mainly having a function of generating charges when the photoconductive layer 602 is functionally separated. This charge generation layer 605 is composed of a-Si: H containing at least silicon atoms as a constituent element, substantially not containing carbon atoms, and if necessary containing hydrogen atoms, and has desired photoconductive properties, particularly charge generation. Characteristics and charge transport characteristics.

  The layer thickness of the charge generation layer 605 is appropriately determined as desired from the viewpoint of obtaining desired electrophotographic characteristics and economic effects, etc., preferably 0.5 μm to 15 μm, more preferably 1 μm to 10 μm, optimal Is 1 μm or more and 5 μm or less.

  In the amorphous silicon photosensitive member 600 that can be used in this embodiment, a surface layer 603 can be further provided on the photoconductive layer 602 formed on the support 601 as described above, if necessary. The amorphous silicon-based surface layer 603 is preferably formed. The surface layer 603 has a free surface and is provided to achieve the object of the present embodiment mainly in moisture resistance, continuous repeated use characteristics, electrical pressure resistance, use environment characteristics, and durability.

  The layer thickness of the surface layer 603 in this embodiment is usually 0.01 μm or more and 3 μm or less, preferably 0.05 μm or more and 2 μm or less, and most preferably 0.1 μm or more and 1 μm or less. If the layer thickness is less than 0.01 μm, the surface layer 603 is lost due to wear or the like during use of the photoreceptor 600, and if it exceeds 3 μm, electrophotographic characteristics such as an increase in residual potential are observed.

(Surf fixing device)
FIG. 7 is a schematic diagram of the surf fixing device of the present embodiment.

  Referring to FIG. 7, a fixing device 800 is a so-called surf fixing device that fixes a fixing film 801 by rotating it in the direction of the arrow in the drawing. More specifically, the fixing film 801 is an endless belt-like heat-resistant film. A driving roller 802 which is a support rotating body of the film, a driven roller 803, and a heating body 804 provided below the two rollers in the figure. Suspended.

  The driven roller 802 also serves as a tension roller for the fixing film 801. The fixing film 801 is rotationally driven in the direction of the arrow in the drawing by the rotational driving of the driving roller 802 in the direction of the arrow in the drawing. The rotational driving speed is adjusted to a speed at which the speeds of the transfer material 806 and the fixing film 801 are equal in the fixing nip region L where the pressure roller 805 and the fixing film 801 are in contact with each other.

  Here, the pressure roller 805 is a roller having a rubber elastic layer having good releasability such as silicon rubber, and the total pressure is 4 kg or more and 10 kg or less with respect to the fixing nip region L while rotating in the arrow direction in the figure. The contact is made with contact pressure.

  The fixing film 801 is preferably a film having excellent heat resistance, releasability, and durability, and a thin film having a total thickness of 100 μm or less, preferably 40 μm or less. For example, a single layer film of heat-resistant resin such as polyimide, polyetherimide, PES (polyether sulfide), and PFA (tetrafluoroethylene bar fluoroalkyl vinyl ether copolymer resin), and a composite layer film, for example, 20 μm thick At least the image contact surface side of the film is provided with a 10 μm thick release coat layer in which a conductive material is added to a fluororesin such as PTFE (tetrafluoroethylene resin) and PFA, An elastic layer is applied.

  The heating body 804 is composed of a flat substrate 807 and a fixing heater 808. The flat substrate 807 is made of a material having high thermal conductivity and high electrical resistivity such as alumina and has a surface in contact with the fixing film 801. Is provided with a fixing heater 808 made of a resistance heating element in the longitudinal direction. The fixing heater 808 is formed by applying an electric resistance material such as Ag / Pd or Ta2N in a linear or belt shape by screen printing or the like. In addition, electrodes (not shown) are formed at both ends of the fixing heater 808, and the resistance heating element generates heat when energized between the electrodes. Further, a fixing temperature sensor 809 constituted by a thermistor is provided on the surface opposite to the surface provided with the fixing heater 808 of the substrate.

  The substrate temperature information detected by the fixing temperature sensor 809 is sent to a control unit (not shown), and the amount of electric power supplied to the fixing heater is controlled by the control unit, so that the heating body 804 is controlled to a predetermined temperature.

  Hereinafter, embodiments will be described in more detail with reference to examples. In the following, “parts” means parts by weight, and “%” means percent by weight.

<Preparation of toner fine powder 1>
(Synthesis of organic fine particle emulsion)
In a reaction vessel equipped with a stirrer and a thermometer, 683 parts of water, 11 parts of sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries), 80 parts of styrene, 83 parts of methacrylic acid, When 110 parts of butyl acrylate, 12 parts of butyl thioglycolate and 1 part of ammonium persulfate were added and stirred at 400 rpm for 15 minutes, a white emulsion was obtained. This emulsion was heated and reacted at a system temperature of 75 ° C. for 5 hours. After the reaction, 30 parts of 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 5 hours to give a vinyl resin (styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt). An aqueous dispersion was obtained. This aqueous dispersion is referred to as [fine particle dispersion 1].

  The volume average particle diameter of this [fine particle dispersion 1] measured with a laser diffraction particle size distribution analyzer (LA-920, manufactured by Shimadzu Corporation) was 120 nm. Further, a part of [Fine Particle Dispersion 1] was dried to isolate the resin component. The glass transition point of this resin was 42 ° C., and the weight average molecular weight was 30,000.

(Preparation of aqueous phase)
990 parts of water, 65 parts of [fine particle dispersion 1], 37 parts of a 48.5% aqueous solution of dodecyl diphenyl ether disulfonate (Eleminol MON-7, manufactured by Sanyo Chemical Industries) and 90 parts of ethyl acetate are mixed and stirred. A milky white liquid was obtained.

(Synthesis of low molecular weight polyester)
229 parts of bisphenol A ethylene oxide 2-mole adduct, 529 parts of bisphenol A propylene oxide 3-mole adduct, 208 parts of terephthalic acid, 46 parts of adipic acid in a reaction vessel equipped with a condenser, a stirrer, and a nitrogen introduction pipe And 2 parts of dibutyltin oxide were allowed to react at normal pressure and 230 ° C. for 8 hours, and further reacted under reduced pressure conditions of 1.3 × 10 ^{3 to} 2.0 × 10 ³ Pa for 5 hours. After the reaction, 44 parts of trimellitic anhydride was put in a reaction vessel and reacted at 180 ° C. and normal pressure for 2 hours to obtain [Low molecular weight polyester 1]. [Low molecular polyester 1] had a number average molecular weight of 2500, a weight average molecular weight of 6700, a glass transition point of 43 ° C., and an acid value of 25 KOH mg / g.

(Synthesis of intermediate polyester)
682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, trimellitic anhydride in a reaction vessel equipped with a condenser, a stirrer, and a nitrogen introduction pipe 22 parts of acid and 2 parts of dibutyltin oxide were allowed to react at normal pressure and 230 ° C. for 8 hours, and further reacted at a reduced pressure of 1.3 × 10 ^{3 to} 2.0 × 10 ³ Pa for 5 hours. Body polyester 1] was obtained. [Intermediate Polyester 1] had a number average molecular weight of 2,100, a weight average molecular weight of 9,500, a glass transition point of 55 ° C., an acid value of 0.5 KOH mg / g, and a hydroxyl value of 51 KOH mg / g.

(Synthesis of a modified polyester resin capable of reacting with a compound having at least an active hydrogen group)
In a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe, 410 parts of [Intermediate polyester 1], 89 parts of isophorone diisocyanate, and 500 parts of ethyl acetate are allowed to react at 100 ° C. for 5 hours. Polymer 1] was obtained. The weight percentage of free isocyanate in [Prepolymer 1] was 1.53%.

(Synthesis of ketimine)
In a reaction vessel equipped with a stir bar and a thermometer, 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were placed and reacted at 50 ° C. for 5 hours to obtain [ketimine compound 1]. The amine value of [ketimine compound 1] was 418.

(Synthesis of master batch)
1200 parts of water, 40 parts of carbon black (Regal 400R, manufactured by Cabot Corporation), 60 parts of polyester resin (RSE-801, manufactured by Sanyo Chemical Industries, number average molecular weight 3500, weight average molecular weight 19000, glass transition point 63 ° C.), and water 30 The parts were mixed with a Henschel mixer (Mitsui Mining Co., Ltd.). This mixture was kneaded at 150 ° C. for 30 minutes using two rolls, rolled and cooled, and pulverized with a pulverizer to obtain [Masterbatch 1].

(Preparation of oil phase)
In a container equipped with a stirrer and a thermometer, 400 parts of [Low molecular weight polyester 1], 110 parts of carnauba wax, and 947 parts of ethyl acetate are added and kept at 80 ° C. for 5 hours with stirring, then 30 ° C. for 1 hour. Cooled to. Next, 500 parts of [Masterbatch 1] and 500 parts of ethyl acetate were placed in a container and mixed for 1 hour to obtain [Raw material solution 1].

  [Raw material solution 1] 1324 parts are transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.), a liquid feeding speed of 1 kg / hour, a disk peripheral speed of 6 m / second, and 0.5 mm zirconia beads are 80% by volume. The wax was dispersed under filling and three-pass conditions. Next, 1324 parts of a 65% ethyl acetate solution of [low molecular weight polyester 1] was added, and dispersion was carried out for 1 pass by a bead mill under the above conditions to obtain [Pigment / Wax Dispersion 1]. The solid content concentration of [Pigment / Wax Dispersion 1] (130 ° C., 30 minutes) was 50%.

(Emulsification)
[Pigment / Wax Dispersion 1] 648 parts, [Prepolymer 1] 154 parts, and [Ketimine Compound 1] 8.5 parts are put in a container and 5,000 rpm with a TK homomixer (made by Tokushu Kika). Mix for 1 minute. 1200 parts of [Aqueous phase 1] was added to this mixed solution, and mixed for 20 minutes at a rotational speed of 10,000 rpm with a TK homomixer to obtain [Emulsified slurry 1].

  That is, it is dispersed in an aqueous medium containing resin fine particles and an elongation reaction is performed.

(Solvent removal)
[Emulsion slurry 1] was put into a container equipped with a stirrer and a thermometer, and after removing the solvent at 30 ° C. for 8 hours, aging was carried out at 45 ° C. for 4 hours to obtain [Dispersion slurry 1].

(Washing / drying / classification)
[Dispersion slurry 1] After 100 parts of the filtrate were filtered under reduced pressure, 100 parts of ion-exchanged water was added to the filter cake, mixed with a TK homomixer at 12,000 rpm for 10 minutes, and then filtered to obtain filter cake A.

  100 parts of a 10% aqueous sodium hydroxide solution was added to filter cake A, and the mixture was mixed for 30 minutes at 12000 rpm with a TK homomixer, followed by filtration under reduced pressure to obtain filter cake B.

  100 parts of 10% hydrochloric acid was added to the filter cake B, mixed with a TK homomixer at 12,000 rpm for 10 minutes, and then filtered to obtain a filter cake C.

  After adding 300 parts of ion-exchanged water to the filter cake C and mixing with a TK homomixer at 12,000 rpm for 10 minutes, the operation of filtering was performed twice to obtain a cake. This is designated as [filter cake 1].

  [Filter cake 1] was dried at 45 ° C. for 48 hours by a circulating dryer. Thereafter, the mixture was sieved with a mesh of 75 μm and classified by elbow jet to obtain toner base particles and toner fine powder. This is made [Toner Base Particle 1] (Dv = 4.9 μm) and [Toner Fine Powder 1] (Dv = 3.4 μm).

<Preparation of toner fine powder 2>
(Washing / drying / classification)
[Dispersion slurry 1] After 100 parts of the filtrate were filtered under reduced pressure, 100 parts of ion-exchanged water was added to the filter cake, mixed with a TK homomixer at 12,000 rpm for 10 minutes, and then filtered to obtain filter cake A.

  100 parts of a 10% aqueous sodium hydroxide solution was added to filter cake A, and the mixture was mixed for 30 minutes at 12000 rpm with a TK homomixer, followed by filtration under reduced pressure to obtain filter cake B.

  100 parts of 10% hydrochloric acid was added to the filter cake B, mixed with a TK homomixer at 12,000 rpm for 10 minutes, and then filtered to obtain a filter cake C.

  After adding 300 parts of ion-exchanged water to the filter cake C and mixing with a TK homomixer at 12,000 rpm for 10 minutes, the operation of filtering was performed twice to obtain a cake. This is designated as [filter cake 1].

  [Filter cake 1] was dried at 45 ° C. for 48 hours by a circulating dryer. Thereafter, it was sieved with a mesh of 106 μm and classified by elbow jet to obtain toner base particles and toner fine powder. This is converted into [Toner Base Particle 2] (Dv = 5.5 μm) and [Toner Fine Powder 2] (Dv = 4.7 μm).

<Example 1>
(Preparation of aqueous phase)
990 parts of water, 65 parts of [fine particle dispersion 1], 37 parts of a 48.5% aqueous solution of sodium dodecyldiphenyl ether disulfonate (Eleminol MON-7, manufactured by Sanyo Chemical Industries), 90 parts of ethyl acetate, and another lot 120 parts of [Toner fine powder 1] (Dv = 3.4 μm) removed in the classification process when the toner particles were produced were mixed and stirred to obtain a light brown liquid. This is designated as [Aqueous Phase 2].

  [Toner base particle 3] (Dv = 5.5 μm) was obtained in the same process as [Preparation of toner fine powder 1] except that [Water phase 2] was used.

(External additive treatment)
[Toner base particle 3] To 100 parts of toner, 0.7 part of hydrophobic silica and 0.3 part of hydrophobic titanium oxide as external additives were mixed in a Henschel mixer to obtain a toner. This is referred to as [Toner 1].

(Developer adjustment)
A two-component developer comprising 5% of [toner base particles 1] and 95% of a copper-zinc ferrite carrier coated with a silicon resin and having an average particle diameter of 40 μm was prepared. Using this two-component developer, continuous printing using Ricoh's imgio Neo 450 (hereinafter referred to as an evaluation machine) capable of printing A4 size paper at 45 sheets / minute and evaluating by the following method did.

<Example 2>
(Preparation of aqueous phase)
990 parts of water, 65 parts of [fine particle dispersion 1], 37 parts of a 48.5% aqueous solution of sodium dodecyldiphenyl ether disulfonate (Eleminol MON-7, manufactured by Sanyo Chemical Industries), 90 parts of ethyl acetate, and another lot 120 parts of [Toner fine powder 2] (Dv = 4.7 μm) removed in the classification process when the toner particles were produced were mixed and stirred to obtain a light brown liquid. This is designated as [Aqueous Phase 2].

  A toner was prepared in the same manner as in Example 1 except that [Aqueous Phase 2] was used, and [Toner 2] was obtained.

<Comparative Example 1>
(Preparation of aqueous phase)
990 parts of water, 65 parts of [fine particle dispersion 1], 37 parts of a 48.5% aqueous solution of sodium dodecyldiphenyl ether disulfonate (Eleminol MON-7, manufactured by Sanyo Chemical Industries), 90 parts of ethyl acetate, and another lot 320 parts of [Toner fine powder 1] (Dv = 3.4 μm) removed in the classification process when the toner particles were produced were mixed and stirred to obtain a light brown liquid. This is designated as [Aqueous Phase 3].

  A toner was prepared in the same manner as in Example 1 except that [Aqueous Phase 3] was used, and [Toner 3] was obtained.

<Comparative example 2>
(Preparation of aqueous phase)
990 parts of water, 65 parts of [fine particle dispersion 1], 37 parts of a 48.5% aqueous solution of sodium dodecyldiphenyl ether disulfonate (Eleminol MON-7, manufactured by Sanyo Chemical Industries), 90 parts of ethyl acetate, and another lot 320 parts of [Toner fine powder 2] (Dv = 4.7 μm) removed in the classification process when the toner particles were produced were mixed and stirred to obtain a light brown liquid. This is designated as [Aqueous Phase 4].

  A toner was prepared in the same manner as in Example 1 except that [Aqueous Phase 4] was used, and [Toner 4] was obtained.

<Comparative Example 3>
Using [Toner Base Particle 1] (Dv = 4.9 μm) prepared in the toner fine powder 1 preparation step, toner is prepared in the external additive treatment step in the same manner as in Example 1 to obtain [Toner 5]. It was.

<Evaluation method>
The volume average particle diameter (Dv), the value of Dv / Dn, and the measurement of the average circularity were evaluated by performing the measurement using the method described above.

(Cleanability)
The transfer residual toner on the photosensitive member that passed through the cleaning process after outputting 100 sheets was transferred to a white paper with a scotch tape (manufactured by Sumitomo 3M Co., Ltd.), and measured with a Macbeth reflection densitometer RD514 type. At this time, the difference from the blank is less than 0.005, ◯, 0.005 or more and 0.010 or less, ◯, 0.011 or more and 0.02 or less, Δ, and more than 0.02. Was evaluated as x.

(Image density)
After running 150,000 image charts with 50% image area in monochromatic mode, a solid image was output to 6000 paper manufactured by Ricoh, and the image density was measured by X-Rite (manufactured by X-Rite). . This was measured independently for each of the four color toners, and the average value of the measured values of the four color toners was determined. When this average value is less than 1.2, x, when 1.2 or more and less than 1.4, Δ, when 1.4 or more and less than 1.8, or when 1.8 or more and less than 2.2 Was evaluated as ◎.

(Image graininess and sharpness)
A photographic image was output in a single color, and the degree of graininess and sharpness was visually sensory evaluated. Evaluate from the good ones in four stages, ◎, ○, △, and ×, the degree of offset printing is ◎, slightly worse than offset printing, ○, considerably worse than offset printing, △ The photographic image grade was marked with x.

(Skin dirt)
After running 30,000 image charts with 50% image area in monochrome mode, the blank image is stopped during development, and the developer on the photoconductor after development is transferred with a tape. The difference in image density from the tape was measured by a 938 spectrodensitometer (manufactured by X-Rite). The smaller the difference in image density, the less the background stain, and the evaluation was made in four stages of ◎, ○, Δ, and × in the order of the less background stain.

(Outline in character image)
After running 30,000 image charts with a 50% image area in single color mode, the character image is overlaid on the RHP type DX OHP sheet and output, and the toner image is not transferred. The frequency was compared with the stage sample. Rank 1 is the lowest, rank 5 is the highest, rank 1 and 2 are evaluated as x, rank 3 is evaluated as Δ, rank 4 is evaluated as ○, and rank 5 is evaluated as ◎.

(Toner fluidity)
A powder tester (PT-N type, manufactured by Hosokawa Micron Corporation) was loaded with meshes having openings of 75 μm, 45 μm, and 22 μm in order from the top. 2 g of the toner base was placed on the uppermost 75 μm mesh, 1 mm vibration was applied in the vertical direction for 10 seconds, and the fluidity (cohesion degree) of the toner base was calculated from the amount of residual toner on each mesh and the following equation.

Aggregation degree (%) = (5 × (residual toner amount (g) on 75 μm mesh) + 3 × (residual toner amount (g) on 45 μm mesh) + (residual toner amount (g) on 22 μm mesh)) × 10
The case where the degree of aggregation was less than 8% was evaluated as ◎, the case where it was 8% or more and less than 16%, ◯, the case where it was 16% or more and less than 25%, and the case where it was 25% or more, ×.

(Fixability)
Print a solid image on plain paper and thick paper transfer paper (type 6200 and NBS Ricoh copy printing paper <135>, manufactured by Ricoh) and fix it with a recording paper of 0.85 ± 0.1 mg / cm ^2. Sex was evaluated. A fixing test was performed by changing the temperature of the fixing belt, and an upper limit temperature at which hot offset did not occur on plain paper was defined as an upper limit fixing temperature. Further, the minimum fixing temperature was measured with a thick paper. The lower limit fixing temperature was determined as the fixing lower limit temperature at the fixing roll temperature at which the residual ratio of the image density after rubbing the obtained fixed image with a pad was 70% or more. The fixing upper limit temperature was evaluated as ◎ when the temperature was 190 ° C or higher, ◯ when the temperature was 180 ° C or higher and lower than 190 ° C, Δ when the temperature was 170 ° C or higher and lower than 180 ° C, and x when the temperature was lower than 170 ° C. The lower limit fixing temperature was evaluated as ◎ when the temperature was less than 135 ° C, ◯ when the temperature was 135 ° C or more and less than 145 ° C, and Δ when the temperature was 145 ° C or more and less than 155 ° C.

表１及び表２を参照するに、別ロットにてトナーを製造したときの分級工程により除去された所定の粒径より小さいトナーである微粉を、水系媒体相中に所定量混合した実施例１及び２のトナーは、微粉を過剰量加えた比較例１及び２のトナーに比べて、低温定着性が優れていた。また、実施例１及び２のトナーは、水系媒体相中に微粉を混合しない比較例３のトナーに比べて優れたクリーニング性を示しながらも、画像濃度、画像粒状性・鮮鋭性。地汚れ、文字部白抜け、トナー流動性、及び定着性については、比較例３と比べて概ね遜色ない結果を示すことが確認された。

Referring to Tables 1 and 2, Example 1 was obtained by mixing a predetermined amount of fine powder, which is a toner having a particle size smaller than the predetermined particle size removed by the classification process when the toner was manufactured in a different lot, into the aqueous medium phase. The toners No. 1 and No. 2 were superior in low-temperature fixability to the toners of Comparative Examples 1 and 2 in which an excessive amount of fine powder was added. In addition, the toners of Examples 1 and 2 exhibit image density, image graininess, and sharpness while exhibiting excellent cleaning properties as compared with the toner of Comparative Example 3 in which fine powder is not mixed in the aqueous medium phase. It was confirmed that the background stain, the white portion of the character portion, the toner fluidity, and the fixing property were almost the same as those of Comparative Example 3.

  According to the embodiments and examples, it is possible to provide a method for producing a toner that is excellent in cleaning properties and has a high quality image by reusing fine powder out of non-predetermined toner as a material. . In addition, since the fine powder that could not be used as the toner can be reused, the yield in toner production can be improved. This improvement in toner yield means a reduction in waste associated with toner production, and the toner production method of this embodiment and this example is a method that takes into consideration the protection of the natural environment.

  The preferred embodiments and examples of the present invention have been described in detail above, but the present invention is not limited to the specific embodiments, and within the scope of the gist of the present invention described in the claims, Various modifications and changes are possible.

It is a block diagram of the process cartridge in the embodiment of the present invention. 1 is a configuration diagram (No. 1) of an image forming apparatus of an embodiment. FIG. 3 is a configuration diagram (part 2) of the image forming apparatus according to the exemplary embodiment. FIG. 3 is a configuration diagram (No. 3) of the image forming apparatus according to the embodiment. FIG. 5 is a partial enlarged view of a configuration diagram (No. 3) of the image forming apparatus of the present embodiment. It is a typical block diagram for demonstrating the layer structure of the amorphous silicon photoconductor of this embodiment. 1 is a schematic diagram of a surf fixing device of the present embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Photoconductor 10K Photoconductor for black, 10Y Photoconductor for yellow 10M Photoconductor for magenta, 10C Photoconductor for cyan 14, 15, 16 Support roller 17 Intermediate transfer cleaning device 18 Image forming means 20 Charge roller 21 Charger 22 Secondary Transfer device 23 Roller 24 Secondary transfer belt 25 Fixing device 26 Fixing belt 27 Pressure roller 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 Developer 41 Developing belts 42K, 42Y, 42M, 42C Developer accommodating portions 43K, 43Y, 43M, 43C Developer supply rollers 44K, 44Y, 44M, 44C Developing rollers 45K Black developing device, 45Y Yellow developing device 45M Magenta developing device, 45C Cyan Developer 49 Registor 50 Intermediate transfer member 51 Roller 52 Separation roller 53 Manual feed path 55 Switching claw 56 Discharge roller 57 Discharge tray 58 Corona charger 60, 90 Cleaning device 61 Developer 62 Transfer charger 63 Photoconductor cleaning device 64 Charger removal device 70 Charge removal lamp 80 Transfer roller 95 Transfer paper 99 Process cartridge 100A, 100B Image forming apparatus 120 Tandem type image forming apparatus 130 Document base 142 Paper feed roller 143 Paper bank 144 Paper feed cassette 145 Separating rollers 146, 148 Paper feed path 147 Conveying roller 150 Copying apparatus Main body 200 Paper feed table 300 Scanner 400 Automatic document feeder (ADF)
600 photoconductor 601 support 602 photoconductive layer 603 surface layer 604 charge injection blocking layer 605 charge generation layer 606 charge transport layer 800 fixing device 801 fixing film 802 driving roller 803 driven roller 804 heating member 805 pressure roller 806 transfer material 807 plane Substrate 808 Fixing heater 809 Fixing temperature sensor

Claims (14)

A granulating step of granulating the toner by emulsifying and / or dispersing an organic solvent phase comprising at least a binder resin and / or a binder resin monomer in an aqueous medium phase; A method for producing a toner having a classification step of classifying the toner to obtain a toner having a particle size;
A method for producing a toner, comprising mixing the fine powder, which is the toner smaller than the predetermined particle diameter, removed by the classification step when the toner is produced in another lot in the aqueous medium phase. . The relationship between the volume average particle diameter A of the toner having the predetermined particle diameter and the volume average particle diameter B of the fine powder is as follows:
0.1 × A ≦ B ≦ 0.9 × A
The toner production method according to claim 1, wherein:   The toner production method according to claim 1, wherein the fine powder is contained in an amount of 20 parts by weight or less based on 100 parts by weight of the aqueous medium phase.   The method for producing toner according to claim 3, wherein the fine powder is contained in an amount of 10 parts by weight or less based on 100 parts by weight of the aqueous medium phase.   The toner production method according to claim 1, wherein the toner has a volume average particle diameter (Dv) of 3 μm or more and 8 μm or less.   The ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) of the toner is 1.25 or less. Toner production method.   The toner manufacturing method according to claim 1, wherein an average circularity of the toner is 0.90 or more and 0.98 or less.   A toner manufactured by the toner manufacturing method according to claim 1.   A two-component developer comprising the toner according to claim 8. A charging unit that uniformly charges the image carrier; a developing unit that develops an electrostatic latent image formed on the image carrier into a toner image; and the toner image on the image carrier on a recording material. And an image forming apparatus including a fixing unit that fixes the image
The image forming apparatus, wherein the developing unit holds the toner according to claim 8. Charging means for uniformly charging the image carrier, developing means for developing the electrostatic latent image formed on the image carrier into a toner image, and transferring the toner image on the image carrier onto a film An image forming method comprising: a transfer unit that heats and a heat fixing unit that heat-fixes the toner image on the film onto a recording material;
The image forming apparatus, wherein the developing unit holds the toner according to claim 8.   12. The image forming apparatus according to claim 10, wherein the charging unit contacts the image carrier and applies a voltage to uniformly charge the image carrier.   The image forming apparatus according to claim 10, wherein the image carrier is an amorphous silicon photoconductor. In a process cartridge for an image forming apparatus, which is detachable from an image forming apparatus main body and has at least a photosensitive member, a charging unit, a developing unit, and a cleaning unit.
9. A process cartridge, wherein the developing means holds the toner according to claim 8.

Images