JP4589210B2 - Toner, toner manufacturing method, and image forming apparatus - Google Patents

Description

  The present invention relates to an image forming toner used as a developer for developing an electrostatic image in electrophotography, electrostatic recording, electrostatic printing, and the like, and a method for producing the same. Furthermore, the present invention relates to an image forming apparatus using the toner.

  In the developing process, the developer used in electrophotography, electrostatic recording, electrostatic printing, etc. is once attached to an image carrier such as a photoreceptor on which an electrostatic charge image is formed, and then After being transferred from the photoreceptor to a transfer medium such as transfer paper in the transfer process, it is fixed on the transfer medium surface in the fixing process. At that time, as a developer for developing the electrostatic image formed on the latent image holding surface, a two-component developer composed of a carrier and a toner, and a one-component developer that does not require a carrier (magnetic toner, Non-magnetic toners are known.

Conventionally, dry toners used for electrophotography, electrostatic recording, electrostatic printing, etc. are mainly composed of a thermoplastic resin as a main component, a colorant and a charge control agent, and a toner composition such as wax to further improve the fixability. A composition obtained by mixing, melt-kneading and then pulverizing and classifying the composition is used.
When this method is used, a classification step is required to make the kneaded composition (toner) have a desired particle size, and the yield of the toner is reduced. In particular, in order to obtain a high-quality image, a particle size of about 5 to 7 μm is desired. However, in order to obtain a toner in this region by the pulverization method, the yield of the toner is significantly reduced. It is not practical as a method of obtaining.

Therefore, a method for directly producing toner without including a pulverization step has been proposed. As these methods, there is a toner production method by suspension polymerization as described in Patent Documents 1 and 2.
In this method, a polymerizable monomer, a polymerization initiator, a colorant, and a toner component are suspended in an aqueous dispersion medium, and then a polymerization reaction is performed to directly produce a toner. The toner obtained by way of this process for the manufacture is simplified, as described in Patent Document 3, the inorganic fine particles used in combination with the polymeric dispersion stabilizer in the dispersion stabilizer in an aqueous dispersion medium Thus, it is possible to obtain a toner having a uniform particle size distribution that does not require classification.

  In addition, there are toner manufacturing methods by dispersion polymerization as described in Patent Documents 4 to 6. The toner obtained by the dispersion polymerization method has a sharper particle size than the above-mentioned pulverization method and suspension polymerization method, and the toner image using this is particularly excellent in halftone and re-line reproducibility and high image quality. This toner has a high potential for realizing it.

  However, in the toner obtained by suspension polymerization or dispersion polymerization, the dispersion stabilizer used at the time of polymerization remains on the toner surface, and the charging characteristics of the toner are almost governed by the dispersion stabilizer used. Therefore, studies have been made to control the charging of the toner by attempting chemical modification of the dispersion stabilizer. However, in these methods, the initial charging characteristics are good, but the stability over time is poor, and it is necessary to introduce a charge control agent into a part of the toner surface layer.

For example, Patent Document 7 discloses a method in which a charge control agent is fixed to the outside of particles by mechanical energy on the surface of fine particles. Patent Document 8 discloses a method in which resin fine particles and charge control agent are adhered to the outside of particles by mechanical energy. Each method of fixing is proposed. However, in the method in which the charge control agent is fixed to the surface of the fine particles by mechanical energy, it is difficult to fix the charge control agent uniformly because the particle size distribution of the fine particles is wide, and the heat between the charge control agent and the fine particles is difficult. If the characteristics are different, there is a problem that the fixing characteristics of the fine particles are hindered. Furthermore, even in the method in which the resin fine particles and the charge control agent are fixed to the surface of the fine particles by mechanical energy, it is difficult to uniformly fix substances having different compositions and properties such as the resin fine particles and the charge control agent, and charge control is difficult. .
Therefore, as a technique for avoiding the problem of the method of fixing the charge control agent by mechanical energy as described above, there is a method of performing a surface treatment for imparting charge in a liquid as described in Patent Document 9, for example.

Moreover, in patent document 10, the construction method with volume shrinkage called the polymer solution suspension method is examined. In this method, a toner material is dispersed and dissolved in a volatile solvent such as a low-boiling organic solvent, and this is emulsified and formed into droplets in an aqueous medium containing a dispersant, and then the volatile solvent is removed. Unlike suspension polymerization and emulsion polymerization agglomeration methods, this method is a versatile resin that can be used, especially polyester resins useful for full-color processes that require transparency and smoothness of the image area after fixing. It is excellent in that it can be used.
However, the used dispersant is strongly adsorbed on the surface of the toner particles, and it is difficult to remove it by a subsequent washing operation. Along with this, the chargeability of the toner is largely governed by the used dispersant. It was. Accordingly, the average charge level of the obtained toner is low, the charging speed is slow, and it is strongly influenced by humidity.

  Further, in Patent Document 11, the resin used in the polymer dissolution suspension method has a low molecular weight to reduce the viscosity of the dispersed phase, facilitate emulsification, and improve the fixing property by causing a polymerization reaction in the particles. The influence of the functional group used for the polymerization reaction in the particles cannot be ignored. Especially when an isocyanate compound is used, not only the influence of the dispersant described above, but also the chargeability of the resulting urethane and urea groups is strongly controlled. It was a thing.

Therefore, as a means for solving the above problems caused by the polymer suspension method, Patent Document 12 describes a method for obtaining stable charging characteristics by adding a surfactant having a reverse polarity.
However, in Patent Document 9 and Patent Document 12 described above, since the charge control agent is applied wet, it is necessary to dry the moisture contained in the toner after externally adding the charge control agent. Due to the difference in the drying time, the charging characteristics of the toner after drying vary, resulting in problems such as background smearing in the obtained image.

Japanese Patent Laid-Open No. 3-113464 JP-A-6-32908 JP-A-6-320908 JP-A-3-258803 Japanese Patent Laid-Open No. 3-190903 JP-A-6-222617 Japanese Patent Laid-Open No. 62-209541 JP-A-63-198070 Japanese Patent Laid-Open No. 5-281787 JP-A-7-152202 JP-A-11-149179 JP 2004-054139 A

  SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and its problem is to provide a stable image having a small particle size, excellent fixability, stable charging performance, and free from defects such as background stains. It is an object of the present invention to provide a toner that can be used and an image forming apparatus that uses the toner.

The features of the present invention, which is a means for solving the above problems, are listed below.
1. The present invention is a toner containing at least a binder resin and a colorant, and obtained by wet external addition of a charge control agent on the surface. The toner is obtained by granulating in an aqueous medium. The binder resin contains a resin having a carboxyl group terminal; at least one of the charge control agents is a compound having a nonmetallic cation group; and the toner is granulated in an aqueous medium. The toner is characterized in that the moisture content of the toner cake after the dehydration filtration after the external addition of the charge control agent to the toner base particles thus obtained and before the drying is 35% by mass or less.
2. The toner of the present invention is 1. In the invention described in item 3, the non-metallic cation of the charge control agent is preferably an ammonium ion.
3. The toner of the present invention is 1. Or 2. In the invention described in Item 3, the charge control agent is preferably a fluorine-containing quaternary ammonium salt compound.
4). The toner of the present invention is 1. Or 3. In the invention according to any one of the above, the binder resin preferably contains a polyester resin.
5). The toner of the present invention is 1. Or 4. In the invention described in any one of the above, the acid value of the binder resin is preferably 10 to 45 KOH mg / g.
6). The toner of the present invention is 1. Or 5. In any one of the inventions, it is preferable that the aqueous medium contains organic resin fine particles.
7). In addition, the toner of the present invention has 6. In the invention described in item 3, it is preferable that the organic resin fine particles have a carboxyl group at a terminal.
8). The toner of the present invention is 1. Or 7. In any one of the inventions described above, the average circularity is preferably 0.90 to 0.98.
9. The toner of the present invention is 1. Or 8. In the invention according to any one of the above, the volume average particle size is 3.0 to 8.0 μm, and the ratio (Dv / Dn) of the volume average particle size (Dv) to the number average particle size (Dn) is 1.00. it is not preferred in the range of ～1.40.
10. The toner of the present invention is 1. Or 9. In the invention according to any one of the above, it is preferable that the toner is used by mixing with a magnetic carrier coated with a resin.

11. The toner manufacturing method of the present invention is a toner manufacturing method containing at least a binder resin and a colorant, and the toner manufacturing method obtains toner base particles by granulating in an aqueous medium. A granulation step, a step of adding a charge control agent to the slurry in which the toner base particles are redispersed in an aqueous medium and wet-adding the slurry, a step of dehydrating and filtering the slurry to obtain a toner cake, and the toner And a step of drying the cake, wherein the binder resin contains a resin having a carboxyl group terminal, and at least one of the charge control agents is a compound having a nonmetallic cation group. In addition, the moisture content of the toner cake after the dehydration filtration step after the external addition of the charge control agent and before the drying step is 35% by mass or less.
12 A method of manufacturing a toner of the present invention, 11. In the invention described in item 3, the drying time of the step of drying the toner cake is preferably 60 hours or less.
13. Further, the method for producing the toner further comprises 2. Or 10. It is preferable that the toner is a method for producing a toner according to any one of the above.

14 Further, the image forming apparatus of the present invention includes a latent image carrier that carries a latent image, a charging unit that uniformly charges the surface of the latent image carrier, and image data on the surface of the charged latent image carrier. An exposure means for exposing and writing an electrostatic latent image, a developing means for supplying toner to the electrostatic latent image formed on the surface of the latent image carrier to visualize it, and the surface of the latent image carrier The image forming apparatus includes a transfer unit that transfers the visible image to the recording member, and a fixing unit that fixes the visible image on the recording member. The toner used in the developing unit is at least a binder resin. And a colorant, and a toner obtained by wet external addition of a charge control agent on the surface, wherein the toner is obtained by granulating in an aqueous medium, and the binder resin has a carboxyl group terminal And at least one of the charge control agents is a non-metallic cation The toner has a water content of a toner cake after dehydration filtration after wet addition of the charge control agent to toner base particles obtained by granulation in an aqueous medium and before drying. Is 35% by mass or less.
15. The image forming apparatus further includes: Or 10. It is preferable that the image forming apparatus uses the toner described in any of the above.

16. Further, the image forming apparatus of the present invention is described in 14. Or 15. The image forming apparatus main body integrally supports an image carrier that carries an electrostatic latent image and at least a developing device that is disposed to face the image carrier that carries an electrostatic latent image. It is preferable to include a process cartridge that can be attached to and detached from.

  According to the present invention, it is possible to provide a toner that has excellent dot reproducibility, developability, and transferability, as well as good charging characteristics, little background stains, and good fixability. Further, a process cartridge using the toner of the present invention as a developer or an image forming apparatus can provide a high-quality image with no abnormal image and excellent fixability.

In the toner of the present invention, a charge control agent is added to toner base particles obtained by granulating a toner composition comprising a binder resin containing at least a carboxyl group-terminated compound and a colorant in an aqueous medium. A toner obtained by wet external addition, and a compound having at least a nonmetallic cation is used as a charge control agent.
The wet treatment is, for example, by adding a dispersion of a charge control agent to a liquid in which toner base particles are dispersed, and adhering the charge control agent to the surface of the toner base particles in the liquid. This is a method in which the charge control agent is uniformly attached, and the charge control agent can be uniformly attached as compared with the dry external addition treatment in which the charge control agent is mechanically attached to the surface of the toner base particles.
In the present invention, by using a compound having a nonmetallic cation as a charge control agent, a carboxyl group in the resin contained in the binder resin, a nonmetallic cation, Interact with each other to form a bond, thereby improving the adhesion of the charge control agent on the toner surface.

As the charge control agent, it is preferable to use a fluorine-based compound. Since the fluorine-based compound has a good affinity with the carboxyl group contained in the binder resin described above, the adhesion to the toner particle surface can be improved. Among the fluorine-based compounds, when a fluorine-containing ammonium salt compound is used, it is easy to dissolve in water containing alcohol, so that it is easy to uniformly fix the toner base particle surface in the above-described wet processing, and charge control is performed. This is preferable because the adhesion of the agent to the toner particle surface can be further improved. Furthermore, by incorporating organic resin fine particles in the aqueous medium for granulating the toner composition, the organic resin fine particles can fix the charge control agent on the surface of the toner particles. The property can be further improved.
In addition to this, the toner of the present invention has a charge control agent attached by the above-mentioned wet treatment, dehydrated and filtered, and the moisture content of the toner cake before the drying step is 35% by mass or less. As a result, the adhesion of the charge control agent on the surface of the toner base particles before the drying step can be improved, and the drying time can be set to a predetermined time or less. Therefore, the charging performance of the toner can be improved.

  The image forming toner of the present invention is preferably a toner having a small particle size and a nearly spherical shape so as to output a high-quality and high-definition image. As a method for producing such a toner, there are a suspension polymerization method, an emulsion polymerization method, a polymer suspension method and the like in which an oil phase is emulsified, suspended or aggregated in an aqueous medium to form toner base particles. Hereinafter, these toner production methods and materials, additives, and the like used in the production methods will be described.

(Suspension polymerization method)
A colorant, a release agent and the like are dispersed in an oil-soluble polymerization initiator and a polymerizable monomer, and then emulsified and dispersed by an emulsification method described later in an aqueous medium containing a surfactant and other solid dispersants. Thereafter, after the polymerization reaction to form particles, a wet treatment for attaching a charge control agent to the toner particle surfaces in the present invention may be performed. At that time, it is preferable to treat the toner particles from which excess surfactant and the like are removed by washing.
Polymerizable monomers such as acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride, acrylamide, methacrylamide, diacetone Functional groups can be introduced on the surface of toner particles by using a part of acrylate or methacrylate such as acrylamide or these methylol compounds, vinyl pyridine, vinyl pyrrolidone, vinyl imidazole, ethyleneimine, dimethylaminoethyl methacrylate and other amino groups. .
Further, by selecting a dispersant having an acid group or a basic group as a dispersant to be used, the dispersant can be adsorbed and left on the particle surface to introduce a functional group.

(Emulsion polymerization aggregation method)
A water-soluble polymerization initiator and a polymerizable monomer are emulsified in water using a surfactant, and a latex is synthesized by an ordinary emulsion polymerization technique. Separately, a dispersion in which a colorant, a release agent and the like are dispersed in an aqueous medium is prepared, and after mixing, the toner is aggregated to a toner size and heat-fused to obtain a toner. Thereafter, a wet treatment of a charge control agent described later may be performed. A functional group can be introduced on the surface of the toner particles by using a latex similar to the monomer that can be used in the suspension polymerization method.

(Polymer suspension method)
As an aqueous medium used in the present invention, water alone may be used, but a solvent miscible with water may be used in combination. Examples of the miscible solvent include alcohol (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methylcellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.) and the like.
In the oil phase of the toner composition, a colorant such as a resin, a prepolymer and a pigment, a release agent, a charge control agent and the like are dissolved or dispersed in a volatile solvent.
An oil phase composed of a toner composition is dispersed in an aqueous medium in the presence of a surfactant, a solid dispersant and the like, and a prepolymer is reacted to form particles. Thereafter, a wet treatment of a charge control agent described later may be performed.
In order to introduce a functional group into the toner particles, a copolymer with a monomer having a functional group used in the suspension polymerization method, or a functional group of an acid group as an acid monomer in the case of a polyester resin is used. It can be obtained by using one having three or more or esterifying the terminal hydroxyl group of the obtained polyester resin with a compound having a plurality of acid groups. Further, as a dispersion stabilizer in an aqueous medium described later, an acid group-containing surfactant, polar polymer, organic or inorganic resin fine particles can be used, and an acid group can be introduced by remaining on the toner particle surface. Examples of the acid group include a carboxyl group, a sulfone group, a sulfonic acid group, and a phosphoric acid group.

(Wet treatment of charge control agent)
In common with any of these toner manufacturing methods, the charge control agent can be applied by a wet process. It is preferable to perform this step after the toner particles are formed in water and the used surfactant and the like are removed by washing. Excess surfactant present in water is removed by solid-liquid separation such as filtration and centrifugation, and the resulting cake and slurry are redispersed in an aqueous medium.
Thereafter, an aqueous solution in which a compound used as a charge control agent is dispersed is gradually added with stirring.
The charge control agent is usually in the form of a powder, but a solution or a fine particle dispersion can be obtained in an aqueous medium or a water / alcohol mixed medium. In the present invention, compounds preferably used as the charge control agent are described in detail below.
The compound used as the charge control agent can be used in an amount of 0.01 to 1% by weight based on the solid content of the toner particles.

  Furthermore, the resin fine particle dispersion may be present in the slurry redispersed for the purpose of reinforcing the chargeability. The resin fine particle dispersion is preferably obtained by emulsion polymerization. By adding a surfactant having a reverse polarity, the charge in the resin fine particle dispersion in water is neutralized, and can be agglomerated and adhered to the toner particle surface. The resin fine particles can be used in an amount of 0.01 to 5% by weight based on the solid content of the toner particles.

  The charge control agent and resin fine particles adhered to the toner surface can be fixed on the toner surface by heating the slurry thereafter to prevent detachment. At that time, it is preferable to heat at a temperature higher than the Tg of the resin constituting the toner. You may heat-process after drying.

  In the present invention, examples of the fluorine-based compound used as the charge control agent include a fluorine-containing quaternary ammonium salt compound and a compound containing a metal-containing azo dye in combination with a fluorine-containing quaternary ammonium salt compound. These may be used individually by 1 type and may use 2 or more types together. Among these, a fluorine-containing quaternary ammonium salt compound is particularly preferable from the viewpoint of excellent chargeability with time.

  There is no restriction | limiting in particular as a fluorine-containing quaternary ammonium salt compound, According to the objective, it can select suitably from well-known things, For example, the compound represented by following Structural formula (1) is mentioned suitably.

In the structural formula (1), Rf represents a perfluoroalkyl group. As a perfluoroalkyl group, a C3-C30 thing is preferable and a 3-15 thing is more preferable. Specifically, for _{example, CF 3 (CF 2) 5} -, CF 3 (CF 2) 6 -, CF 3 (CF 2) 7 -, CF 3 (CF 2) 8 -, CF 3 (CF 2) 9 _{-, CF 3 (CF 2)} 10 -, CF 3 (CF 2) 11 -, CF 3 (CF 2) 12 -, CF 3 (CF 2) 13 -, CF 3 (CF 2) 14 -, CF 3 ( _{CF 2) 15 -, CF 3} (CF 2) 16 -, CF 3 (CF 2) 17 -, (CF 3) 2 CF (CF 2) 6 -, and the like preferably.

  In Structural Formula (1), Y represents a counter ion. Examples of counter ions include halogen ions, sulfate ions, nitrate ions, phosphate ions, thiocyanate ions, organic acid ions, and the like. Among these, halogen ions such as fluorine, chlorine, bromine and iodine are particularly preferable.

In the structural formula (1), X represents a divalent organic group. The divalent organic group, for _{example, -SO 2 -, - CO -} , - (CH 2) x -, - SO 2 N (R 5) - (CH 2) x -, - (CH 2) x-CH _{(OH) - (CH 2)} x-, and the like. Here, x represents an integer of 1 to 6. R ⁵ represents an alkyl group having 1 to 10 carbon atoms. Among _{these, -SO 2 -, - CO -} , - (CH 2) 2 -, - SO 2 N (C 2 H 5) - (CH 2) 2 -, or _{-CH 2 CH (OH) CH 2} - Are preferred, and —SO ₂ — or —CO— is particularly preferred.
In Structural Formula (1), s represents an integer of 1 or more, preferably 1 to 20, and more preferably 1 to 10.

In Structural Formula (1), R ¹ represents a hydrogen atom, a fluorine atom, or a hydrocarbon group.
R ^{2 to} R ⁴ may be the same as or different from each other, and each represents a hydrogen atom, a fluorine atom, or a hydrocarbon group. There is no restriction | limiting in particular as this hydrocarbon group, Although it can select suitably according to the objective, For example, an alkyl group, an alkenyl group, an aryl group, etc. are mentioned. These may be further substituted with a substituent.
The alkyl group is preferably one having 1 to 10 carbon atoms, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, n-hexyl group, isohexyl. Group, n-heptyl group, n-octyl group, isooctyl group, n-decyl group, isodecyl group, and the like, and these may be further substituted with a substituent. As the alkenyl group, those having 2 to 10 carbon atoms are more preferable, and examples thereof include a vinyl group, an allyl group, a propenyl group, an isopropenyl group, a butenyl group, a hexenyl group, an octenyl group, and the like. And may be further substituted. As the aryl group, those having 6 to 24 carbon atoms are more preferable, and examples thereof include phenyl group, tolyl group, xylyl group, cumenyl group, styryl group, mesityl group, cinnamyl group, phenethyl group, and benzhydryl group. These may be further substituted with a substituent.

Further, the binder resin in the organic solvent composition of the present invention preferably contains a polyester resin. Polyester resins are easier to lower in molecular weight than styrene acrylic resins, have excellent low-temperature fixability, and are preferable for energy saving. The terminal carboxyl group of the polyester resin is used as the charge control agent. Since it can interact with the contained cation, adhesion of the charge control agent on the toner surface can be improved.
Furthermore, the acid value of the binder resin in the organic solvent composition is preferably in the range of 10 to 45 KOH mg / g. When the acid value of the binder resin is within the above range, the interaction with the cation of the charge control agent can be effectively obtained, and the adhesiveness to paper can be improved. . If the acid value of the toner is less than 10 KOH mg / g, sufficient interaction with the charge control agent cannot be obtained in the aqueous medium, and adhesion of the charge control agent to the surface of the toner base particles becomes insufficient. Further, the adhesion of the resulting toner to paper is lowered, and a good image cannot be obtained. On the other hand, when the acid value exceeds 45 KOHmg / g, the stability in the system during emulsification increases and the coalescence of fine particles does not progress, so that it is difficult to obtain a toner having a sharp particle size distribution.
The acid value measuring method of the present invention is based on a method based on JIS K0070.
However, when the sample does not dissolve, a solvent such as dioxane or THF is used as the solvent.

  Binder resins that can be used in the present invention include polyester resins, styrene such as polystyrene, poly p-chlorostyrene, and polyvinyltoluene, and substituted polymers thereof; styrene-p-chlorostyrene copolymers, 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-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile Copolymer, styrene-vinyl methyl ketone Styrene copolymers such as polymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-acrylonitrile-indene copolymers, styrene-maleic acid copolymers, styrene-maleic acid ester copolymers; 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, fat Aromatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes and the like can be mentioned, and these can be used alone or in combination.

The polyester resin that can be used in the present invention is usually obtained by condensation polymerization of alcohol and carboxylic acid.
Examples of the alcohol include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, and propylene glycol, etherified bisphenols such as 1.4-bis (hydroxymethyl) cyclohexane and bisphenol A, and other divalent alcohols. And trihydric or higher polyhydric alcohol monomers. Examples of carboxylic acids include divalent organic acid monomers such as maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, and malonic acid, 1,2,4-benzenetricarboxylic acid, 1 , 2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methylenecarboxy Mention may be made of trivalent or higher polyvalent carboxylic acid monomers such as propane and 1,2,7,8-octanetetracarboxylic acid.

Further, the method for producing the toner and toner base particles used in the present invention contains a polymer having a site capable of reacting with a compound having an active hydrogen group in an organic solvent, and is granulated in an aqueous medium. It is preferable to include a high molecular weight process for reacting with a compound having an active hydrogen group.
In the toner according to the present invention, the base particles are produced by the following raw materials and production methods, for example.

(Modified polyester)
The toner according to the present invention contains a modified polyester (i) as a binder resin. The modified polyester (i) refers to a state in which a bonding group other than an ester bond is present in the polyester resin, or resin components having different configurations are bonded to the polyester resin by a covalent bond, an ionic bond, or the like. Specifically, the polyester terminal is modified by introducing a functional group such as a carboxylic acid group or an isocyanate group that reacts with a hydroxyl group into the polyester terminal and further reacting with an active hydrogen-containing compound.

  Examples of the modified polyester (i) include urea-modified polyester obtained by a reaction between a polyester prepolymer (A) having an isocyanate group and amines (B). As the polyester prepolymer (A) having an isocyanate group, a polyester having a polycondensate of a polyhydric alcohol (PO) and a polyvalent carboxylic acid (PC) and having an active hydrogen group is further added to a polyvalent isocyanate compound (PIC). And those reacted with. 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, a mercapto group, and the like. Among these, an alcoholic hydroxyl group is preferable.

The urea-modified polyester is produced as follows.
Examples of the polyhydric alcohol compound (PO) include dihydric alcohol (DIO) and trihydric or higher polyhydric alcohol (TO). (DIO) alone or a mixture of (DIO) and a small amount of (TO) preferable. Examples of the dihydric alcohol (DIO) include alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol) , Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol) F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Alkylene oxide bisphenol (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts. 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 and alkylene glycols having 2 to 12 carbon atoms. It is a combined use. As trihydric or higher polyhydric alcohol (TO), 3 to 8 or higher polyhydric aliphatic alcohol (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.

  Examples of the polyvalent carboxylic acid (PC) include divalent carboxylic acid (DIC) and trivalent or higher polyvalent carboxylic acid (TC). (DIC) alone and (DIC) with a small amount of (TC) Mixtures are preferred. Divalent carboxylic acids (DIC) include alkylene dicarboxylic acids (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid) And naphthalenedicarboxylic acid). 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 polyvalent carboxylic acid (TC) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). In addition, as polyhydric carboxylic acid (PC), you may make it react with polyhydric alcohol (PO) using the above-mentioned acid anhydride or lower alkyl ester (Methyl ester, ethyl ester, isopropyl ester, etc.).

  The ratio of the polyhydric alcohol (PO) to the polycarboxylic acid (PC) is usually 2/1 to 1/1, preferably as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. Is 1.5 / 1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.

  Examples of the polyvalent isocyanate compound (PIC) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.) Aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanates; Those blocked with caprolactam or the like; and combinations of two or more of these.

  The ratio of the polyvalent isocyanate compound (PIC) is usually 5/1 to 1/1, preferably as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 4/1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. When the molar ratio of [NCO] is less than 1, when a urea-modified polyester is used, the urea content in the ester is lowered and hot offset resistance is deteriorated.

The content of the polyvalent isocyanate compound (PIC) component in the polyester prepolymer (A) having an isocyanate group is usually 0.5 to 40 wt%, preferably 1 to 30 wt%, more preferably 2 to 20 wt%. . If it is less than 0.5 wt%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40 wt%, the low-temperature fixability deteriorates.
The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2 on average. Five. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester will be low, and the hot offset resistance will deteriorate.

Next, as amines (B) to be reacted with the polyester prepolymer (A), a divalent amine compound (B1), a trivalent or higher polyvalent amine compound (B2), an amino alcohol (B3), an amino mercaptan (B4) ), Amino acid (B5), and amino acid block of B1 to B5 (B6).
Examples of the divalent amine compound (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexyl). Methane, diamine cyclohexane, isophorone diamine, etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.) and the like. Examples of the trivalent or higher polyvalent amine compound (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 compound (B6) obtained by blocking the amino group of B1 to B5 include ketimine compounds and oxazolidine compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines (B), preferred are B1 and a mixture of B1 and a small amount of B2.

The ratio of amines (B) is equivalent to the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the polyester prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). Is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. When [NCO] / [NHx] is more than 2 or less than 1/2, the molecular weight of the urea-modified polyester is lowered, and the hot offset resistance is deteriorated.
The urea-modified polyester may contain a urethane bond together with a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.

The modified polyester (i) used in the present invention is produced by a one-shot method or a prepolymer method. The weight average molecular weight of the modified polyester (i) is usually 10,000 or more, preferably 20,000 to 10,000,000, more preferably 30,000 to 1,000,000. The peak molecular weight at this time is preferably 1000 to 10,000, and if it is less than 1,000, the elongation reaction hardly occurs and the elasticity of the toner is small, and as a result, the resistance to hot offset deteriorates. On the other hand, if it exceeds 10,000, the problem in production becomes high in the case of a decrease in fixability, particle formation or pulverization. The number average molecular weight of the modified polyester (i) is not particularly limited when the unmodified polyester (ii) described later is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. (I) When used alone, the number average molecular weight is usually 20000 or less, preferably 1000 to 10000, and more preferably 2000 to 8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color device are deteriorated.
In the crosslinking and / or extension reaction between the polyester prepolymer (A) and the amines (B) to obtain the modified polyester (i), a reaction terminator is used as necessary to adjust the molecular weight of the resulting urea-modified polyester. be able to. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).

(Unmodified polyester)
In the present invention, not only the modified polyester (i) is used alone, but also the unmodified polyester (ii) can be contained as a binder resin component together with the (i). By using (ii) in combination, the low-temperature fixability and the gloss when used in a full-color device are improved, which is preferable to the single use. Examples of (ii) include polycondensates of a polyhydric alcohol (PO) and a polyvalent carboxylic acid (PC), which are the same as the polyester component (i), and preferred ones are also the same as (i). . Further, (ii) is not limited to unmodified polyester, but may be modified with a chemical bond other than a urea bond, for example, may be modified with a urethane bond. It is preferable that (i) and (ii) are at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance. Therefore, the polyester component (i) and (ii) preferably have similar compositions. In the case of containing (ii), the weight ratio of (i) to (ii) is usually 5/95 to 80/20, preferably 5/95 to 30/70, more preferably 5/95 to 25/75, Particularly preferred is 7/93 to 20/80. If the weight ratio of (i) is less than 5%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

  The peak molecular weight of (ii) is 1000-10000 normally, Preferably it is 2000-8000, More preferably, it is 2000-5000. 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 (ii) is preferably 5 or more, more preferably 10 to 120, and particularly preferably 20 to 80. If it is less than 5, it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. As for the acid value of (ii), 1-5 are preferable, More preferably, it is 2-4. Since a high acid value wax is used for the wax, the low acid value of the binder resin component leads to chargeability and high volume resistance, so it is easy to match the toner used in the two-component developer.

  The glass transition point (Tg) of the binder resin is usually 35 to 70 ° C., preferably 55 to 65 ° C. If the temperature is lower than 35 ° C., the heat-resistant storage stability of the toner deteriorates, and if it exceeds 70 ° C., the low-temperature fixability becomes insufficient. Since the urea-modified polyester is likely to be present on the surface of the obtained toner base particles, the toner of the present invention tends to have good heat storage stability even when the glass transition point is low, as compared with known polyester-based toners. Show.

(Coloring agent)
As the colorant, 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 Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Phi Sayred, Parachlor Ortonito Aniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine B, 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, Thio Indigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red Polyazo Red, Chrome Vermillion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), indigo, ultramarine 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, Lid Russian nin green, anthraquinone green, titanium oxide, zinc white, litbon and mixtures thereof can be used. The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the toner.

  The colorant can also be used as a master batch combined with a resin. As a binder resin to be kneaded with the production of the master batch or the master batch, a polymer of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyl toluene or the like, or a copolymer of these and a vinyl compound, 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, fat Aromatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes and the like can be mentioned, and these can be used alone or in combination.

(Release agent)
As the release agent, a low melting point wax having a melting point of 50 to 120 ° C. works more effectively as a release agent in the dispersion with the binder resin between the fixing roller and the toner interface, thereby fixing. Effective against high temperature offset without applying a release agent such as oil to the roller. Examples of such a wax component include the following. Examples of waxes and waxes include plant waxes such as carnauba wax, cotton wax, wood wax, rice wax, animal waxes such as beeswax and lanolin, mineral waxes such as ozokerite and cercin, and paraffin, microcrystalline, And petroleum waxes such as petrolatum. In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax and polyethylene wax, and synthetic waxes such as esters, ketones, and ethers can be used. Furthermore, fatty acid amides such as 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, chlorinated hydrocarbon, and low molecular weight crystalline polymer resin, poly-n-stearyl methacrylate, poly-n- A crystalline polymer having a long alkyl group in the side chain such as a homopolymer or copolymer of polyacrylate such as lauryl methacrylate (for example, a copolymer of n-stearyl acrylate-ethyl methacrylate, etc.) can also be used. .
The release agent can be melt-kneaded together with the master batch and the binder resin, and of course, it may be added when dissolved and dispersed in the organic solvent.

Next, a toner manufacturing method will be described. Here, although a preferable manufacturing method is shown, it is not limited to this.
(Toner production method)
1) A toner material solution is prepared by dispersing a colorant, unmodified polyester, a polyester prepolymer having an isocyanate group, and a release agent in an organic solvent.
The organic solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal after toner base particle formation. Specifically, toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, Methyl isobutyl ketone and the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform, and carbon tetrachloride are preferable. The usage-amount of an organic solvent is 0-300 weight part normally with respect to 100 weight part of polyester prepolymers, Preferably it is 0-100 weight part, More preferably, it is 25-70 weight part.

2) The toner material liquid is emulsified in an aqueous medium in the presence of a surfactant and resin fine particles.
The aqueous medium may be water alone or an organic solvent such as alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.). It may be included.
The amount of the aqueous medium used relative to 100 parts by weight of the toner material liquid is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight. If the amount is less than 50 parts by weight, the dispersion state of the toner material liquid is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 20000 parts by weight, it is not economical.

Further, in order to improve the dispersion in the aqueous medium, a dispersant such as a surfactant and resin fine particles is appropriately added.
As surfactants, anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazoline, Quaternary ammonium salt type cationic surfactants such as alkyltrimethylammonium salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkylisoquinolinium salt, benzethonium chloride, fatty acid amide derivative, polyhydric alcohol Nonionic surfactants such as derivatives, for example, amphoteric surfactants such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl-N, N-dimethylammonium 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 fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [ω-fluoroalkyl (C6-C11 ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [ω-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carvone Acids and metal salts, perfluoroalkylcarboxylic acids (C7 to C13) and metal salts thereof, perfluoroalkyl (C4 to C12) sulfonic acids and metal salts thereof, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- ( 2-Hydroxyethyl) Perful Olooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Can be mentioned.
Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (manufactured by Daikin Industries, Ltd.), Megafac F-110, F-120, F-113, F-191, F-812, F-833 (manufactured by Dainippon Ink, Inc.), Xtop EF-102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fgentent F-100, F150 (manufactured by Neos).

  Further, as the cationic surfactant, aliphatic quaternary ammonium salts such as aliphatic primary, secondary or secondary amine acids having a fluoroalkyl group, and perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salts. , Benzalkonium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (manufactured by Asahi Glass), Florard FC-135 (manufactured by Sumitomo 3M), Unidyne DS-202 (Daikin Industries) Manufactured), MegaFuck F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-132 (Tochem Products Co., Ltd.), Footgent F-300 (Neos Co., Ltd.), and the like.

(Organic resin fine particles)
The aqueous medium of the present invention preferably further contains organic resin fine particles in order to fix a surface treatment agent (charge control agent) for imparting charge. The organic fine particles may be any resin that can form an aqueous dispersion, and may be a thermoplastic resin or a thermosetting resin. For example, vinyl resins, polyurethane resins, epoxy resins, polyester resins, polyamide resins, polyimides Examples thereof include resins, silicon-based resins, phenol resins, melamine resins, urea resins, aniline resins, ionomer resins, and polycarbonate resins. As the organic 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 is 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 include styrene-acrylonitrile copolymers, styrene-maleic anhydride copolymers, styrene- (meth) acrylic acid copolymers, styrene- (meth) acrylic acid- (meth) acrylic acid ester copolymers, and the like.

  In order to fix the surface treatment agent, the organic resin fine particles preferably have a carboxyl group in the terminal structure. Further, the organic resin fine particles are more unevenly distributed on the surface of the organic resin fine particles to fix the surface treatment agent. The carboxyl group is preferably derived from acrylic acid or methacrylic acid. Styrene- (meth) acrylic acid ester resin, (meth) acrylic acid-acrylic acid ester polymer, styrene- (meth) acrylic acid copolymer, styrene- (meth) acrylic acid- (meth) acrylic acid ester copolymer A coalescence etc. can be used preferably.

  As a dispersant that can be used in combination with the above resin fine particles and inorganic compound dispersant, the dispersed droplets may be stabilized by a polymer protective colloid. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups Bodies such as acrylic acid-β-hydroxyethyl, methacrylic acid-β-hydroxyethyl, acrylic acid-β-hydroxypropyl, methacrylic acid-β-hydroxypropyl, acrylic acid-γ-hydroxypropyl, methacrylic acid-γ-hydroxy Propyl, acrylic acid-3-chloro-2-hydroxypropyl, methacrylic acid-3-chloro-2-hydroxypropyl, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate Luric acid esters, N-methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, or compounds containing vinyl alcohol and a carboxyl group Esters such as vinyl acetate, vinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl Nitrogen compounds such as imidazole and ethyleneimine, or homopolymers or copolymers such as those having a heterocyclic ring thereof, polyoxyethylene, poly Xoxypropylene, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxy Polyoxyethylenes such as ethylene nonylphenyl ester, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.

  The dispersion method is not particularly limited, and known equipment 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. Among these, the high-speed shearing method is preferable in order to make the particle size of the dispersion 2 to 20 μm. When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 40 to 98 ° C.

3) At the same time as the preparation of the emulsion, the amines (B) are added to cause a reaction with the polyester prepolymer (A) having an isocyanate group.
This reaction involves molecular chain crosslinking and / or elongation. The reaction time is selected depending on the reactivity between the isocyanate group structure of the polyester prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours. The reaction temperature is generally 0 to 150 ° C, preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.

4) After completion of the reaction, the organic solvent is removed from the emulsified dispersion (reactant), washed and dried to obtain toner base particles.
When a dispersant is used, the dispersant may 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. For washing and removing, the aqueous dispersion is subjected to solid-liquid separation with a centrifuge, a spatula filter and / or a filter press, etc., and water is added to the obtained resin particles to repeat solid-liquid separation in a similar manner. Is mentioned. Further, in order to remove the organic solvent, a method in which the temperature of the entire system is gradually raised and the organic solvent in the droplets is completely removed by evaporation can be employed. Alternatively, it is also possible to spray the emulsified dispersion in a dry atmosphere to completely remove the water-insoluble organic solvent in the droplets to form toner fine particles, and to evaporate and remove the aqueous dispersant together. . As a dry atmosphere in which the emulsified dispersion is sprayed, a gas obtained by heating air, nitrogen, carbon dioxide gas, combustion gas, or the like, particularly various air streams heated to a temperature equal to or higher than the boiling point of the highest boiling solvent used are generally used. Sufficient quality can be obtained with a short treatment such as spray dryer, belt dryer or rotary kiln. At this time, spindle-shaped toner base particles can be produced by gradually raising the temperature of the entire system in a laminar stirring state, giving strong stirring in a certain temperature range, and then removing the solvent. In addition, by giving strong agitation in the process of removing the organic solvent, the shape between the spherical shape and the rugby ball shape can be controlled, and the surface morphology is also controlled between the smooth shape and the umeboshi shape. be able to.
Further, when an acid such as calcium phosphate salt or an alkali-soluble material is used as the dispersion stabilizer, the calcium phosphate salt is dissolved from the toner base particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and washing with water. Remove. It can also be removed by operations such as enzymatic degradation.

5) A charge control agent is externally added to the surface of the toner base particles to the toner base particles thus obtained by the wet process described above. Further, the slurry is dehydrated and filtered to perform solid-liquid separation, and then dried to remove the aqueous medium, whereby the toner of the present invention can be obtained. This solid-liquid separation operation by dehydration filtration may be repeated a plurality of times by adding water or the like as necessary. After the final step of the solid-liquid separation operation by dehydration filtration, by adjusting the moisture content of the toner cake before being subjected to the drying step to the range shown above, a toner having good chargeability can be obtained. Can do.

  The method for adjusting the moisture content of the toner cake before the drying step to the above range is not limited. The toner cake adjusted to the above water content can be obtained by solid-liquid separation by heat evaporation, natural evaporation, reduced pressure evaporation, dehydration press, centrifugal dehydration and the like, and removing the aqueous medium.

  In the present invention, the water content means the weight of water relative to the weight of solid content, and substantially means the weight of water relative to the dry weight of toner base particles before the drying step. The water content can be calculated by filtering water containing toner in a wet state and measuring the evaporation to dry weight of the solid. The term “water” as used herein means a liquid containing water as a main component. The liquid is compatible with water, such as alcohols and other water-soluble organic solvents, the liquid is incompatible with water, and these liquids. It shall also include dissolved material that dissolves.

<Moisture content>
Specifically, the slurry containing the toner base particles after externally adding the charge control agent is subjected to solid-liquid separation by dehydration filtration, and then the moisture content of the toner cake before drying is set to 35% by mass or less. Is preferred. In the present invention, the toner cake refers to a wet cake-like product obtained by performing wet external addition of a charge control agent on the surface of toner particles and then dehydrating and filtering.
When the water content before drying (toner cake) exceeds the above range, the rate of deterioration of the charging performance of the toner increases in the drying step. Although this mechanism is not clear, if the amount of moisture in the toner cake before being subjected to the drying process is large, this moisture is caused by the carboxyl groups on the surface of the toner base particles and the nonmetallic cations contained in the charge control agent. It is considered that a phenomenon occurs in which the charge control agent is easily detached from the surface of the toner particles in the drying process by acting on the binding and weakening the binding force between the two. In addition, since the time required for drying becomes longer when the water content of the toner cake is high, the charge control agent is more likely to be detached from the surface of the toner base particles. The amount of adhesion cannot be obtained, and a toner having stable chargeability cannot be obtained.
The water content is more preferably 30% or less, still more preferably 25% or less.

By drying the toner cake obtained by adjusting the water content within the above range, final toner particles can be obtained. The drying step in the present invention is a step of removing water contained in the toner cake obtained after the solid-liquid separation operation described above.
As the equipment used for drying, known equipment such as a fluidized bed dryer, a vacuum dryer, and a circulating dryer can be used. Moreover, it classifies using an air classifier or a sieve as needed, and it can also be set as predetermined particle size distribution.
In the present invention, a method of drying with mechanical mixing under an air flow or reduced pressure is particularly preferable. Examples of the apparatus for drying while mechanically mixing under an air current include Agromaster (Hosokawa Micron) and Spin Flash Dryer (Matsubo). Examples of the apparatus for drying while mechanically mixing under reduced pressure include a filter dryer (Tanabe Wiltech Co., Ltd.), an SV mixer (Shinko Pantech Co., Ltd.), a conical blender dryer (Nippon Dryer Co., Ltd.), and the like. The larger the air flow rate (air volume) when drying by air current is, the better the drying is promoted, but it is preferable to suppress it to such an extent that fine particles are not scattered.
The optimum temperature, air volume, degree of reduced pressure, etc. in the drying process vary depending on the shape, mechanism, size, etc. of the apparatus used in the drying process, and can be optimized and used as appropriate.

The time required for the drying step is preferably 60 hours or less.
By setting the moisture content of the toner cake subjected to the drying step within the above range, the time required for the drying step can be 60 hours or less. When the drying time exceeds 60 hours, the charge control agent attached to the toner surface is likely to be detached, and the toner after drying cannot have a sufficient charge amount.

  In addition to the above-described fluorine-based compounds, the obtained toner may be subjected to the following charge control agent implantation and external additive dry processing, if necessary. The injection of the charge control agent and the dry treatment of the external additive are performed by a known method using a mixer or the like.

(Charge control agent)
Known charge control agents can be used, such as nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified 4 Secondary ammonium salts or compounds, tungsten simple substances or compounds, fluorine activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives. Specifically, Bontron 03 of a nigrosine dye, Bontron P-51 of a quaternary ammonium salt, Bontron S-34 of a metal-containing azo dye, E-82 of an oxynaphthoic acid metal complex, E-84 of a salicylic acid metal complex , Phenol-condensate E-89 (above, manufactured by Orient Chemical Co., Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, manufactured by Hodogaya Chemical Co., Ltd.), quaternary ammonium salt copy Charge PSY VP2038, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (Nippon Carlit) Manufactured), copper phthalocyanine, perylene, quinacridone, azo series Fee, a sulfonic acid group, a carboxyl group, and polymer compounds having a functional group such as quaternary ammonium salts. Of these, substances that control the negative polarity of the toner are particularly preferably used.
The amount of charge control agent used is determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, and is not uniquely limited. However, it is preferably used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the charge control agent is reduced, the electrostatic attraction with the developing roller is increased, the flowability of the developer is lowered, and the image density is lowered. Invite.

(External additive)
Inorganic fine particles can be preferably used as an external additive for assisting the fluidity, developability and chargeability of the toner particles. The primary particle diameter of the inorganic fine particles is preferably 5 × ¹⁰ -3 ~2μm, it is particularly preferably 5 × ¹⁰ -3 ~0.5μm. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g. The use ratio of the inorganic fine particles is preferably 0.01 to 5 wt% of the toner, and particularly preferably 0.01 to 2.0 wt%.
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, quartz sand, clay, mica, wollastonite, diatomaceous earth. Examples include soil, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. Among these, as the fluidity-imparting agent, it is preferable to use hydrophobic silica fine particles and hydrophobic titanium oxide fine particles in combination. In particular, when stirring and mixing are performed using particles having an average particle diameter of 5 × 10 ⁻² μm or less, the electrostatic force and van der Waals force with the toner are remarkably improved. Even when stirring and mixing inside the developing device is performed to obtain a good image quality that does not cause the release of the fluidity imparting agent from the toner and does not generate firefly, etc., and further reduces the residual toner. It is done.
Titanium oxide fine particles are excellent in environmental stability and image density stability, but have a tendency to deteriorate the charge rising characteristics. It can be considered large. However, when the addition amount of the hydrophobic silica fine particles and the hydrophobic titanium oxide fine particles is in the range of 0.3 to 1.5 wt%, the charge rising characteristics are not greatly impaired, and the desired charge rising characteristics can be obtained, that is, repeated copying. Stable image quality can be obtained even if

(Average circularity)
<Circularity and circularity distribution>
It is important that the toner of the present invention has a specific shape and shape distribution. An toner having an average circularity of less than 0.90 and an irregular shape that is too far from a spherical shape exhibits satisfactory transferability and dust. A high-quality image with no image cannot be obtained. As a method for measuring the shape, an optical detection band method is suitable in which a suspension containing 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 toner having an average circularity of 0.90 to 0.98, preferably 0.975 to 0.900, which is 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. It has been found that the method is effective for forming a high-definition image having a reproducibility with an appropriate density. More preferably, particles having an average circularity of 0.970 to 0.950 and a circularity of less than 0.94 are 15% or less. Further, when the average circularity is 0.975 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. For example, in development / transfer with a low image area ratio, there is little transfer residual toner, and cleaning defects do not become a problem, but those with a high image area ratio, such as color photographic images, and untransferred due to poor paper feed, etc. The image-formed toner may be generated as a transfer residual toner on the photosensitive member, and if accumulated, the image may be soiled. In addition, the charging roller that contacts and charges the photosensitive member is contaminated, and the original charging ability cannot be exhibited.

The average circularity was measured using a flow type particle image analyzer (Flow Particle Image Analyzer). The measurement method will be described below.
The measurement of toner, toner particles and external additives using a flow type particle image analyzer can be performed using, for example, a flow type particle image analyzer FPIA-2000 manufactured by Toa Medical Electronics Co., Ltd.
The measurement is performed by removing fine dust through a filter, and as a result, nonionic system in 10 ml of water having 10 or less particles within the measuring range (eg, equivalent circle diameter of 0.60 μm or more and less than 159.21 μm) in 10 −3 cm 3 of water. A few drops of a surfactant (preferably Contaminone N manufactured by Wako Pure Chemical Industries, Ltd.) is added, 5 mg of a measurement sample is further added, and the mixture is dispersed for 1 minute under the conditions of 20 kHz, 50 W / 10 cm @ 3 with an ultrasonic dispersing device STM UH-50. Then, a dispersion treatment is further performed for a total of 5 minutes, and a sample dispersion liquid in which the measurement sample has a particle concentration of 4000 to 8000 pieces / 10 −3 cm 3 (targeting particles in the diameter range equivalent to the measurement circle) is set to 0. The particle size distribution of particles having an equivalent circle diameter of 60 μm or more and less than 159.21 μm is measured.
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 on the flow cell so as to be opposite to each other. While the sample dispersion is flowing, strobe light is irradiated at 1/30 second intervals to obtain an image of the particles flowing through the flow cell, so that each particle has a certain range parallel to the flow cell. Photographed as a two-dimensional image. 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 can be measured, and the number based on the equivalent circle diameter distribution and the ratio (number%) of particles having a prescribed equivalent circle diameter can be measured. As shown in Table 1, the results (frequency% and cumulative%) can be obtained by dividing the range of 0.06-400 μm into 226 channels (divided into 30 channels for one 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.

(Volume average particle size)
(Dv / Dn)
The toner for image formation of the present invention has a volume average particle diameter (Dv) of 3.0 to 8.0 μm, and a ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn). Is preferably 1.00 to 1.40. By using a toner having such a particle size and particle size distribution, it is excellent in heat-resistant storage stability, low-temperature fixability, and hot offset resistance, and particularly when used in a full-color copying machine, etc. Sex is obtained.
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 properties. is there. In addition, when the volume average particle size is smaller than the range of the present invention, in the case of a two-component developer, the toner is fused to the surface of the magnetic carrier during a long period of stirring in the developing device, and the charging ability of the magnetic carrier is reduced. When used as a developer, toner filming on the developing roller and toner fusion to a member such as a blade for thinning the toner are likely to occur.
On the contrary, when the volume average particle diameter of the toner is larger than the range of the present invention, it becomes difficult to obtain a high-resolution and high-quality image, and when the balance of the toner in the developer is performed. In many cases, the variation in toner particle size becomes large.
On the other hand, if Dv / Dn exceeds 1.40, the charge amount distribution becomes wide and the resolving power decreases, which is not preferable.

The average particle size and particle size distribution of the toner can be measured by a Coulter counter method, and can be measured using a Coulter counter TA-II or Coulter Multisizer (both manufactured by Coulter Co., Ltd.).
The measurement method is described below.
First, 0.1 to 5 ml of a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of an aqueous electrolytic solution. Here, the electrolytic solution is a solution 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 measurement device is used to measure the volume and number of toner particles or toner using a 100 μm aperture as an aperture. Volume distribution and number distribution are calculated. From the obtained distribution, the weight average particle diameter (D4) and the number average particle diameter of the toner can be obtained.
As channels, 2.00 to less than 2.52 μm; 2.52 to less than 3.17 μm; 3.17 to less than 4.00 μm; 4.00 to less than 5.04 μm; 5.04 to less than 6.35 μm; 6 .35 to less than 8.00 μm; 8.00 to less than 10.08 μm; 10.08 to less than 12.70 μm; 12.70 to less than 16.00 μm; 16.00 to less than 20.20 μm; Uses 13 channels of less than 40 μm; 25.40 to less than 32.00 μm; 32.00 to less than 40.30 μm, and targets particles having a particle size of 2.00 μm to less than 40.30 μm.

(Shape factors SF-1, SF-2)
The toner of the present invention is preferably a toner having a shape factor SF-1 in the range of 100 to 180 and SF-2 in the range of 100 to 180. FIG. 1 is a diagram schematically showing the shape of the toner for explaining the shape factor SF-1 and FIG. 2 is for explaining the shape factor SF-2.
SF-1 is more preferably 110 to 170, more preferably 120 to 160, and particularly preferably 130 to 150. SF-2 is more preferably 110 to 170, more preferably 120 to 160, and particularly preferably 130 to 150.
The shape factors SF-1 and SF-2 are expressed by the following formulas (1) and (2) as described above.
SF-1 = {(MXLNG) ² / AREA} × (100π / 4) (1)
SF-2 = {(PERI) ² / AREA} × ( 100 / 4π ) (2)
When the value of SF-1 is 100, the shape of the toner becomes a true sphere, and becomes larger as the value of SF-1 increases. Further, when the value of SF-2 is 100, the unevenness does not exist on the toner surface, and as the SF-2 value increases, the unevenness of the toner surface becomes more prominent.
The shape factor SF-1 is 100 images of toner particles magnified by a magnification of 500 using an electron microscope (for example, FE-SEM (S-800) manufactured by Hitachi, Ltd., and the same applies hereinafter). Randomly sampled and the image information is sent via an interface to an image analysis device [eg, Nexus NEW CUBE ver. 2.5 (manufactured by NEXUS), Luzex III (manufactured by Nicole) and the like, and so on. It is a value obtained by introducing into and analyzing and calculating from equation (1).
The shape factor SF-2 is obtained by randomly sampling 50 toner particle images magnified to a magnification of 3500 times using an electron microscope, introducing the image information into an image analysis apparatus via an interface, and performing analysis. It is a value obtained from 2).

  When the shape factors SF-1 and SF-2 are both close to 100 and the shape of the toner is close to a true sphere, the contact between the toner and the toner or the toner and the image carrier becomes a point contact. Accordingly, the fluidity is increased and the adhesion between the toner and the image carrier is also weakened, and the transfer rate is increased. The dot reproducibility is also improved. On the other hand, when the toner shape factors SF-1 and SF-2 are large to some extent, the margin for cleaning increases, and there is no problem such as defective cleaning. Therefore, it is preferable that the shape factors SF-1 and SF-2 are in the range of 100 to 180 as a range in which the image quality is not deteriorated from the balance between the two.

(Two-component developer)
The toner of the present invention can be mixed with a magnetic carrier and used as a two-component developer. In this case, the carrier to toner content ratio in the developer is preferably 1 to 10 parts by weight of toner with respect to 100 parts by weight of carrier. As the magnetic carrier, conventionally known ones such as iron powder, ferrite powder, magnetite powder, 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 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, Halogenated olefin resins such as vinyl, polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin, polycarbonate resins, polyethylene resins, polyvinyl fluoride resins, polyvinylidene fluoride resins, polytrifluoroethylene resins, polyhexafluoro Propylene resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene and vinylidene fluoride and non- Monomers including a fluoro terpolymers such, and silicone resins. Moreover, you may contain electrically conductive powder etc. in coating resin as needed. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide or 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.

(Single component developer)
The toner of the present invention can also be used as a one-component magnetic toner that does not use a carrier or a non-magnetic toner.

In addition, when preparing the developer, in order to improve the fluidity, storage stability, developability, and transferability of the developer, the hydrophobic silica fine particles listed above are further listed in the developer produced as described above. Inorganic fine particles such as powder may be added and mixed. For mixing external additives, a general powder mixer is used, but it is preferable to equip a jacket or the like to adjust the internal temperature. In order to change the load history applied to the external additive, the external additive may be added in the middle or gradually. Of course, you may change the rotation speed of a mixer, rolling speed, time, temperature, etc. A strong load may be given first, then a relatively weak load, and vice versa.
Examples of the mixing equipment that can be used include a V-type mixer, a rocking mixer, a Ladige mixer, a Nauter mixer, a Henschel mixer, and the like.

An image forming apparatus using the image forming toner of the present invention as a developer will be described.
FIG. 3 is a schematic configuration diagram showing an example of an image forming apparatus according to the present invention. In the figure, reference numeral 100 is a copying apparatus main body, 200 is a paper feed table on which the copying apparatus is placed, 300 is a scanner mounted on the copying apparatus main body 100, and 400 is an automatic document feeder (ADF) mounted thereon.
The copying apparatus main body 100 has a tandem type in which four image forming units 18 each having various units for performing an electrophotographic process such as charging, developing, and cleaning are arranged in parallel around a photosensitive member 40 as a latent image carrier. An image forming apparatus 20 is provided. Above the tandem type image forming apparatus 20, there is provided an exposure apparatus 21 that exposes the photoreceptor 40 with laser light based on image information to form a latent image. Further, an intermediate transfer belt 10 made of an endless belt member is provided at a position facing each photoconductor 40 of the tandem type image forming apparatus 20. A primary transfer unit 62 for transferring the toner images of the respective colors formed on the photoconductor 40 to the intermediate transfer belt 10 is disposed at a position facing the photoconductor 40 via the intermediate transfer belt 10.
A secondary transfer device 22 that collectively transfers the toner images superimposed on the intermediate transfer belt 10 onto transfer paper conveyed from the paper feed table 200 is disposed below the intermediate transfer belt 10. The secondary transfer device 22 is configured by spanning a secondary transfer belt 24 that is an endless belt between two rollers 23, and is disposed by pressing against the support roller 16 via the intermediate transfer belt 10. The toner image on 10 is transferred onto a transfer sheet. A fixing device 25 for fixing the image on the transfer paper is provided beside the secondary transfer device 22. The fixing device 25 is configured by pressing a pressure roller 27 against a fixing belt 26 that is an endless belt.
The secondary transfer device 22 described above also has a sheet transport function for transporting the transfer paper after image transfer to the fixing device 25. Of course, a transfer roller or a non-contact charger may be arranged as the secondary transfer device 22, and in such a case, it is difficult to provide this sheet conveyance function together.
In the illustrated example, a reversing device 28 for reversing the transfer paper so as to record images on both sides of the transfer paper is provided below the secondary transfer device 22 and the fixing device 25 in parallel with the tandem image forming device 20 described above. .

  The developing device 4 of the image forming unit 18 uses a developer containing the above toner. In the developing device 4, the developer carrying member carries and conveys the developer, and an alternating electric field is applied at a position facing the photoconductor 40 to develop the latent image on the photoconductor 40. By applying the alternating electric field, the developer is activated, the charge amount distribution of the toner can be narrowed, and the developability can be improved.

  Further, the developing device 4 can be a process cartridge that is integrally supported with the photoreceptor 40 and is detachably formed on the image forming apparatus main body. In addition, the process cartridge may include a charging unit and a cleaning unit.

The operation of the image forming apparatus is as follows.
First, a document is set on the document table 30 of the automatic document feeder 400, or the automatic document feeder 400 is opened and a document is set on the contact glass 32 of the scanner 300, and the automatic document feeder 400 is closed. Hold it down.
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 other contact glass 32. At that time, the scanner 300 is immediately driven, and the first traveling body 33 and the second traveling body 34 travel. Then, the first traveling body 33 emits light from the light source and further reflects the reflected light from the document surface toward the second traveling body 34 and reflects by the mirror of the second traveling body 34 and passes through the imaging lens 35. The document is placed in the reading sensor 36 and the original content is read.

  When a start switch (not shown) is pressed, one of the support rollers 14, 15, 16 is rotated by a drive motor (not shown), the other two support rollers are driven to rotate, and the intermediate transfer belt 10 is rotated and conveyed. To do. At the same time, the individual image forming means 18 rotates the photoconductor 40 to form black, yellow, magenta, and cyan monochrome images on each photoconductor 40. Then, along with the conveyance of the intermediate transfer belt 10, these single color images are sequentially transferred to form a composite color image on the intermediate transfer belt 10.

On the other hand, when a start switch (not shown) is pressed, one of the paper feed rollers 42 of the paper feed table 200 is selectively rotated, the sheet is fed out from one of the paper cassettes 44 provided in the paper bank 43 in multiple stages, and the separation roller 45 Are separated one by one into the paper feed path 46, conveyed by the conveyance roller 47, guided to the paper feed path 48 in the copying machine main body 100, and abutted against the registration roller 49 and stopped.
Alternatively, the sheet feed roller 50 is rotated to feed out the sheets 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.
Then, the registration roller 49 is rotated in synchronization with the composite color image on the intermediate transfer belt 10, the sheet is fed between the intermediate transfer belt 10 and the secondary transfer device 22, and is transferred by the secondary transfer device 22. A color image is recorded on the sheet.

The image-transferred sheet is conveyed by the secondary transfer device 22 and sent to the fixing device 25. The fixing device 25 applies heat and pressure to fix the transferred image, and then the switching roller 55 is used to switch the discharge image. The paper is discharged at 56 and stacked on the paper discharge tray 57. Alternatively, it is switched by the switching claw 55 and put into the sheet reversing device 28, where it is reversed and guided again to the transfer position, and an image is recorded also on the back surface, and then discharged onto the discharge tray 57 by the discharge roller 56.
On the other hand, the intermediate transfer belt 10 after the image transfer is removed by the intermediate transfer belt cleaning device 17 to remove residual toner remaining on the intermediate transfer belt 10 after the image transfer, so that the tandem image forming apparatus 20 can prepare for the image formation again.

Hereinafter, the present invention will be further described with reference to examples, but the present invention is not limited thereto.
In the following, “parts” means parts by weight, and “%” means percent by weight.

<Example 1>
In the following, “a toner composition comprising at least a binder resin and a colorant is dissolved or dispersed in an organic solvent, and the solution or dispersion is emulsified and dispersed in an aqueous medium to form emulsified particles. A toner obtained by externally adding a charge control agent to emulsified particles to obtain toner base particles, dehydrating and filtering the toner cake containing the toner base particles, and drying the toner cake,
The specific production of the toner, characterized in that the water content of the toner cake after dehydration filtration and before drying is 35% by mass or less, will be described step by step.

~ Synthesis of organic fine particle emulsion ~
In a reaction vessel in which a stir bar and a thermometer were set, 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 for 15 minutes at 400 rpm, a white emulsion was obtained. The system was heated to raise the temperature in the system to 75 ° C. and reacted for 5 hours. Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 5 hours. A dispersion was obtained. This is designated as [fine particle dispersion 1]. The volume average particle size of the [fine particle dispersion 1] measured by a laser diffraction particle size distribution analyzer (LA-920, manufactured by Shimadzu Corp.) was 120 nm. A portion of [Fine Particle Dispersion 1] was dried to isolate the resin component. The Tg of the 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 sodium 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. This is designated as [Aqueous Phase 1].

~ Synthesis of low molecular weight polyester ~
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen inlet tube, 229 parts of bisphenol A ethylene oxide 2-mole adduct, 529 parts of bisphenol A propylene oxide 3-mole adduct, 208 parts terephthalic acid, 46 parts adipic acid and dibutyl Add 2 parts of tin oxide, react at 230 ° C for 8 hours at normal pressure, and further react for 5 hours at 10-15 mmHg reduced pressure, then add 44 parts of trimellitic anhydride to the reaction vessel at 180 ° C at normal pressure. The mixture was reacted 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 Tg of 43 ° C., and an acid value of 25.

~ Synthesis of intermediate polyester ~
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 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 22 And 2 parts of dibutyltin oxide were added, reacted at 230 ° C. for 8 hours at normal pressure, and further reacted for 5 hours at a reduced pressure of 10 to 15 mmHg to obtain [Intermediate Polyester 1]. [Intermediate Polyester 1] had a number average molecular weight of 2,100, a weight average molecular weight of 9,500, Tg of 55 ° C., an acid value of 0.5, and a hydroxyl value of 51.

-Synthesis of a modified polyester resin (referred to as prepolymer 1) capable of reacting with a compound having at least an active hydrogen group-
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introducing tube, 410 parts of the above [intermediate polyester 1], 89 parts of isophorone diisocyanate and 500 parts of ethyl acetate were added and reacted at 100 ° C. for 5 hours. ] Was obtained. [Prepolymer 1] had a free isocyanate weight% of 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 charged and reacted at 50 ° C. for 5 hours to obtain [ketimine compound 1]. The amine value of [ketimine compound 1] was 418.

~ Master batch synthesis ~
1200 parts water, 40 parts carbon black (manufactured by Cabot, Regal 400R), 60 parts polyester resin (manufactured by Sanyo Kasei, RS801), 30 parts water, and mixed with a Henschel mixer (manufactured by Mitsui Mining) The mixture was kneaded at 150 ° C. for 30 minutes using two rolls, rolled and cooled, and pulverized with a pulverizer to obtain [Masterbatch 1].

-Production of toner composition containing oil phase, that is, inorganic fine particles-
In a container equipped with a stir bar and a thermometer, 400 parts of [Low molecular weight polyester 1], 110 parts of carnauba wax and 947 parts of ethyl acetate were charged, heated to 80 ° C. with stirring, and maintained at 80 ° C. for 5 hours. Thereafter, it was cooled to 30 ° C. at 1 hour. Next, 500 parts of [Masterbatch 1] and 500 parts of ethyl acetate were charged 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 is 1 kg / hr, a disk peripheral speed is 6 m / sec, and 0.5 mm zirconia beads are 80% by volume. The wax was dispersed under the conditions of filling and 3 passes. Next, 1324 parts of a 65% ethyl acetate solution of [low molecular weight polyester 1] was added, and one pass was performed with 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, [Ketimine Compound 1] 8.5 parts in a container, and TK homomixer (manufactured by Tokushu Kika) at 5,000 rpm for 1 minute After mixing, 1200 parts of [Aqueous Phase 1] was added to the container and mixed with a TK homomixer at a rotation speed of 10,000 rpm for 20 minutes to obtain [Emulsion 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 performed at 45 ° C for 4 hours to obtain [Dispersion slurry 1].

~Washing~
[Dispersion Slurry 1] After filtering 100 parts under reduced pressure,
(1): 100 parts of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
(2): 1O parts of 10% sodium hydroxide aqueous solution was added to the filter cake of (1), mixed with a TK homomixer (30 minutes at 12,000 rpm), and then filtered under reduced pressure.
(3): 100 parts of 10% hydrochloric acid was added to the filter cake of (2), mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
(4): 300 parts of ion-exchanged water was added to the filter cake of (3), mixed with a TK homomixer (10 minutes at 12,000 rpm), and then filtered twice to obtain a cake-like product. . This is designated as [Filter cake 1].

~ Fluorine treatment ~
[Filter cake 1] is added with 15 parts of [filter cake 1] with respect to 90 parts of water, and N, N, N, -trimethyl- [3- (4) which is a compound of the general formula (1) is added thereto. -Perfluorononenyloxybenzamido) propyl] ammonium iodide (Furgent 310: manufactured by Neos) was dispersed to disperse the fluorine compound on the surface of the toner particles, followed by filtration with a centrifugal dehydrator. Operation was performed to obtain a cake. This is designated as [Filter cake 2]. The water content of [Filter cake 2] was 33% by weight.
The moisture content was measured by sampling a part of [Filter Cake 2] and weighing it at 150 ° C. for 40 minutes before and after drying. As a drying apparatus, Kett 600 was used.

~ Drying process ~
[Filter cake 2-1] having the above water content was dried at 45 ° C. for 48 hours in a circulating dryer. Thereafter, the mixture was sieved with a 75 μm mesh to obtain toner base particles. This is designated as [toner base particle 1].

~ External additive treatment ~
To 100 parts of [Toner Base Particle 1] obtained above, 0.7 part of hydrophobic silica as an external additive and 0.3 part of hydrophobic titanium oxide are mixed with a Henschel mixer to obtain a toner. It was. This is referred to as [Toner 1]. The physical properties of [Toner 1] are listed in Table 1.

-Adjustment of developer-
[Toner 1] A two-component developer comprising 5% by weight and 95% by weight of a copper-zinc ferrite carrier coated with a silicone resin and having an average particle diameter of 40 μm was prepared. Using this developer, continuous printing was carried out using the Ricoh's imgio Neo 450 capable of printing 45 sheets of A4 size paper per minute, and the evaluation results shown below are shown in Table 2. It was.

<Comparative Example 1>
In the dehydration step after the fluorine treatment in Example 1, an operation of filtering with a filter press dehydrator was performed to obtain a cake. This is designated as [Filter cake 2]. [Toner 2] was obtained in the same manner as in Example 1 except that the water content of [Filter cake 2] was 38% by weight.
The water content was measured in the same manner as in Example 1.
The physical property values of [Toner 2] are listed in Table 1.
Further, in the same manner as in Example 1, a two-component developer is prepared by using [Toner 2] and a copper-zinc ferrite carrier to prepare a two-component developer. Evaluation was carried out by the same evaluation method. The obtained evaluation results are shown in Table 2.

[Evaluation methods]
(Evaluation item)
(1) Measurement of Volume Average Particle Size and (Dv / Dn) The toner particle size was measured using a particle size measuring device “Coulter Counter TAII” manufactured by Coulter Electronics Co., Ltd., with an aperture diameter of 100 μm. The volume average particle diameter and the number average particle diameter were determined by the particle size measuring instrument. (Dv / Dn) was automatically calculated from the above values.
(2) Average circularity The average circularity can be measured by a flow type particle image analyzer FPIA-2100 (manufactured by Toa Medical Electronics Co., Ltd.). As a specific measuring method, 0.1 to 0.5 ml of a surfactant, preferably alkylbenzene sulfonate is added as a dispersant to 100 to 150 ml of water from which impure solids have been removed in advance, and further measurement is performed. Add about 0.1-0.5g of sample. The suspension in which the sample is dispersed is obtained by performing dispersion treatment for about 1 to 3 minutes with an ultrasonic disperser and measuring the shape and distribution of the toner with the above apparatus at a dispersion concentration of 3000 to 10,000 / μl. .
(3) Measurement of fluorine content in toner base particles and content of inorganic fine particles present on the surface of toner base particles In the present invention, fluorine content in toner base particles and on the surface of toner base particles The inorganic fine particle content can be measured by the following method. In this case, the region of the extreme surface is about a few nm of the toner surface.
The apparatus used was XPS (X-ray photoelectron spectroscopy). The measurement method, apparatus type, conditions, and the like are not particularly limited as long as similar results can be obtained, but the following conditions are more preferable.
Apparatus: PHI 1600S type X-ray photoelectron spectrometer X-ray source; MgKα (400 W)
Analysis area: 0.8 × 2.0mm
Pretreatment: The sample was packed in an aluminum dish and the surface was smoothed for measurement.
Surface atomic concentration calculation; relative sensitivity factor provided by PHI was used.
The obtained result is atomic% (number of atoms%).
Further, in the measurement of the content of the inorganic fine particles existing on the surface of the toner base particles, when two or more kinds of inorganic fine particles are used, the sum of the element concentrations derived from the inorganic fine particles is used as the calculated analysis value.
(4) Charge amount 6 g of developer is weighed, charged into a metal cylinder that can be sealed, and blown to obtain the charge amount. The toner concentration is adjusted to 4.5 to 5.5 wt%.
(5) Cleaning property Using the evaluation machine A, the transfer residual toner on the photosensitive member that has passed the cleaning process after outputting 100 sheets is transferred to a white paper with a scotch tape (manufactured by Sumitomo 3M Co., Ltd.), and then the Macbeth reflection densitometer. Measured with RD514 type, ◎ if the difference from the blank is less than 0.005, ○ if 0.005 to 0.010, Δ if 0.011 to 0.02, and more than 0.02. Was evaluated as x.
(6) Image Density Using Evaluator A, after running 150,000 sheets of 50% image area image charts in single color mode, a solid image is output to 6000 paper manufactured by Ricoh, and the image density is set to X-Rite. Measurement was carried out by (manufactured by X-Rite). This was performed for four colors alone, and the average was obtained. If this value is less than 1.2, x, if it is 1.2 or more and less than 1.4, Δ, if it is 1.4 or more and less than 1.8, ○, if it is 1.8 or more and less than 2.2 ◎.
(7) Image granularity and sharpness Using the evaluator B, a photographic image was output in a single color, and the degree of granularity and sharpness was visually evaluated. Evaluations were made from GOOD, ◎, ○, Δ, and ×.並 is equivalent to offset printing, ◯ is slightly worse than offset printing, Δ is much worse than offset printing, and × is very bad compared to conventional electrophotographic images.
(8) Background stain After using valuation machine A and running 30,000 image charts with 50% image area in monochrome mode, the blank image is stopped during development, and the developer on the photoreceptor after development is removed. The tape was transferred, and the difference from the image density of the untransferred tape was measured with a 938 spectrodensitometer (manufactured by X-Rite). The smaller the difference in image density, the better the background stains, and the higher the rank in the order of x, Δ, ○, ◎.
(9) White spots inside character images After running 30,000 image charts with 50% image area in monochrome mode using Evaluator A, the character images are printed in four colors on a Ricoh type DX OHP sheet. The frequency of untransferred toner that is output in an overlapping manner and the inside of the line image of the character portion is lost was compared with a step sample. Rank 1 is the lowest and rank 5 is the highest. Rank 1 or 2 was rated as x, Rank 3 was rated as △, Rank 4 was rated as ◯, and Rank 5 was rated as ◎.
(10) Toner fluidity A powder tester (PT-N type, manufactured by Hosokawa Micron) is loaded with meshes of 75 μm, 45 μm, and 22 μm openings in order from the top, and 2 g of the toner base is put on the uppermost 75 μm mesh. Then, a vibration of 1 mm in the vertical direction was applied for 10 seconds, and the fluidity (cohesion degree) of the toner base was calculated from the residual amount of toner on each mesh.
Aggregation degree (%) = (5 × (remaining toner amount (g) on 75 μm mesh))
+ 3 × (residual toner amount on 45 μm mesh (g))
+ (Residual toner amount on 22 μm mesh (g))) × 10
When the degree of aggregation was 8% or less, ◎, when it was 8 to 16%, ○, when it was 16 to 25%, Δ, and when it was 25% or more, ×.
(11) Fixability Using the evaluation machine A, it is 0.85 ± 0.1 mg / cm ^{2 as a} solid image on plain paper and cardboard transfer paper (Ricoh, type 6200 and NBS Ricoh copy printing paper <135>). Fixing was evaluated based on the toner adhesion amount. 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 rated as ◎ for 190 ° C or higher, ◯ for 190-180 ° C, Δ for 180-170 ° C, and x for 170 ° C or lower. The lower limit fixing temperature was ◎ for 135 ° C. or lower, ◯ for 135 to 145 ° C., Δ for 145 to 155 ° C., and × for 155 ° C. or higher.

As can be seen with reference to Table 2, the toner of the present invention shown in Example 1 is excellent in chargeability, excellent in fixability and cleanability, and does not generate images such as background stains and white spots in character portions. Results were obtained.
On the other hand, as can be seen from Table 1, the toner of Comparative Example 1 has a lower fluorine content on the toner surface than the toner of Example 1, and in Table 2, the chargeability of the toner is reduced, and soiling, etc. The occurrence of abnormal images was observed.

FIG. 4 is a diagram schematically illustrating the shape of a toner for explaining a shape factor SF-1. FIG. 6 is a diagram schematically illustrating the shape of a toner for explaining a shape factor SF-2. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present invention.

Explanation of symbols

4 Developing device 10 Intermediate transfer belt (intermediate transfer member)
18 Image forming means 21 Exposure device 25 Fixing device 40 Photosensitive member (latent image carrier)
22 Secondary transfer device 62 Primary transfer means 100 Copier main body 200 Paper feed table 300 Scanner 400 Automatic document feeder

Claims (16)

In a toner containing at least a binder resin and a colorant and obtained by wet-adding a charge control agent to the surface,
The toner is a toner obtained by granulation in an aqueous medium,
The binder resin contains a resin having a carboxyl group end,
At least one of the charge control agents is a compound having a nonmetallic cation group,
The toner has a moisture content of 35% by mass or less after drying and after dehydration filtration after wet addition of the charge control agent to toner base particles obtained by granulation in an aqueous medium. Toner characterized by being. The toner according to claim 1.
The toner according to claim 1, wherein the non-metallic cation of the charge control agent is an ammonium ion. The toner according to claim 1 or 2,
The toner according to claim 1, wherein the charge control agent is a fluorine-containing quaternary ammonium salt compound. The toner according to any one of claims 1 to 3,
The toner according to claim 1, wherein the binder resin contains a polyester resin. In the toner according to any one of claims 1 to 4,
The toner according to claim 1, wherein an acid value of the binder resin is 10 to 45 KOHmg / g. The toner according to any one of claims 1 to 5,
The toner according to claim 1, wherein the aqueous medium contains organic resin fine particles. The toner according to claim 6.
The organic resin fine particles have a carboxyl group at a terminal. The toner according to any one of claims 1 to 7,
The toner has an average circularity of 0.90 to 0.98. The toner according to any one of claims 1 to 8,
The toner has a volume average particle diameter of 3.0 to 8.0 μm and a ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) of 1.00 to 1.40. Toner characterized by being in range. The toner according to claim 1,
The toner is used by mixing with a magnetic carrier coated with a resin. In a method for producing a toner containing at least a binder resin and a colorant,
The method for producing the toner includes a granulation step of granulating in an aqueous medium to obtain toner base particles, and adding a charge control agent to the slurry obtained by redispersing the toner base particles in the aqueous medium to add a wet external additive. A method for producing a toner comprising: a step of dehydrating and filtering the slurry to obtain a toner cake; and a step of drying the toner cake.
The binder resin contains a resin having a carboxyl group end,
At least one of the charge control agents is a compound having a nonmetallic cation group,
The water content of the toner cake after the dehydration filtration step after the external addition of the charge control agent and before the drying step is 35% by mass or less.
And a method for producing the toner. The method for producing a toner according to claim 11, wherein:
The drying time of the step of drying the toner cake is 60 hours or less.
And a method for producing the toner. The method for producing the toner further comprises producing the toner according to claim 2.
And a method for producing the toner. A latent image carrier that carries a latent image, a charging unit that uniformly charges the surface of the latent image carrier, and the surface of the charged latent image carrier is exposed based on image data, whereby an electrostatic latent image is obtained. An exposure unit for writing, a developing unit for supplying toner to the electrostatic latent image formed on the surface of the latent image carrier, and a visible image on the surface of the latent image carrier are transferred to a recording member. In an image forming apparatus including a transfer unit and a fixing unit that fixes a visible image on a recording member.
Toner used in the previous SL developing means includes at least a binder resin contains a colorant, a toner obtained by wet external addition a charge controlling agent to the surface, the toner is in an aqueous medium A toner obtained by granulation, wherein the binder resin contains a resin having a carboxyl group terminal, and at least one of the charge control agents is a compound having a non-metallic cation group, The toner mother particle obtained by granulating in an aqueous medium has a moisture content of 35% by mass or less after the dehydration filtration after the wet addition of the charge control agent and before the drying.
An image forming apparatus. The image forming apparatus further uses the toner according to claim 2.
An image forming apparatus. The image forming apparatus according to claim 14 or 15,
The image forming apparatus integrally supports an image carrier that carries an electrostatic latent image and at least a developing device that is disposed to face the image carrier that carries an electrostatic latent image. With removable process cartridge
An image forming apparatus.

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