JP2010044110A - Method for manufacturing toner, and toner - Google Patents

Abstract

[PROBLEMS] To provide (1) a method for producing a toner having a sharp particle size distribution necessary for obtaining a high-quality image, and (2) to provide a toner having a sharp particle size distribution with small equipment. To provide a method that can be produced efficiently.
SOLUTION: At least a binder resin, a colorant, and a release agent are dissolved or dispersed in an organic solvent, and an oil phase composed of the obtained solution or dispersion and an aqueous medium are supplied to a shearing unit. A toner manufacturing method including an emulsifying step of applying a shearing force to a mixed liquid of the oil phase and the aqueous medium to obtain an emulsified liquid, wherein the mixed liquid of the oil phase and the aqueous medium is the shearing unit. And a method of producing a toner, wherein the oil phase and the aqueous medium are premixed by a premixing unit before passing through the shearing unit, and It is a toner obtained by the toner production method.
[Selection figure] None

Description

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

In recent years, the strong demand for higher image quality from the market has spurred the development of an electrophotographic apparatus suitable for it and a toner developer used therefor. As a toner corresponding to high image quality, it is essential that the toner has a uniform particle size. When the toner particle size is uniform and the particle size distribution becomes sharp, the behavior of individual toner particles during development is aligned, and the reproducibility of minute dots is remarkably improved.
For the above purpose, a toner (hereinafter referred to as a chemical toner) obtained by a suspension polymerization method or an emulsion polymerization aggregation method obtained by granulating in an aqueous phase has been developed.
In the suspension polymerization method, a monomer, a polymerization initiator, a colorant, a release agent, and the like are added to an aqueous phase containing a dispersion stabilizer while stirring to form oil droplets, and then the temperature is raised to cause a polymerization reaction. In this method, toner particles are obtained. According to the suspension polymerization method, although it is possible to reduce the toner particle size, it is necessary to use a dispersion stabilizer that lowers the chargeability when it remains, and if no dispersion stabilizer is used, There is a problem that the release agent tends to enter the oil droplets at the time of formation, and it is difficult to make the release agent appropriately present on the surface of the toner particles.

Further, a release agent fine particle coated with or impregnated with a vinyl polymer by adding a polymerizable vinyl monomer and a water-soluble polymerization initiator to the release agent emulsion for polymerization is added at the time of emulsification of the toner composition. A method of uniformly and firmly adhering to the toner surface has been proposed (Patent Document 1). However, in this method, it is essential to polymerize the release agent emulsion and the polymerizable vinyl monomer, and since the glass transition point (Tg) of the resin constituting the release agent fine particles is high, There exists a problem that it is inferior to releasability, low temperature fixability, etc.
Patent Document 2 discloses a wax having a low melting point that cannot be used in a pulverized toner by producing a toner by suspension polymerization of a polymerizable monomer system containing a substance having a polar group and a release agent in water. It is described that can be contained. Contrary to the polar component, the nonpolar component such as wax does not exist in the vicinity of the surface of the toner particles, and has a pseudo capsule structure covered with the polar component on the surface. However, the wax distribution inside the toner particles has not been analyzed and is unknown.
Patent Document 3 describes a toner in which wax is encapsulated in toner particles and localized on the particle surface. However, the detailed dispersion state of the wax near the toner surface is unknown.
Japanese Patent Application Laid-Open No. H10-228561 defines the ratio of the wax exposed on the toner surface measured by FTIR-ATR. However, toner blocking and hot offset properties, filming and paper wrapping are in a completely trade-off relationship, and it is difficult to improve toner by further improving toner and controlling wax dispersion. It is in.

On the other hand, as a method for producing a chemical toner, a liquid phase of the solution or dispersion obtained by dissolving or dispersing a toner composition comprising at least a resin and a colorant in an organic solvent, or a toner raw material comprising at least a colorant And a method of emulsifying a liquid phase of the dissolved or dispersed product obtained by dissolving or dispersing the compound in a liquid monomer in an aqueous medium. The toner obtained by this method has a smaller particle size (volume average particle size Dv value is smaller) and higher particle size uniformity (Dv / Dn value (Dn is the number average particle size)) than the conventional pulverized toner. (Close to 00). The toner having these properties has a uniform toner particle size, so various toner physical properties such as the charge amount and melting speed of each toner particle are uniform, so that a high-quality image with few image omissions and offsets can be obtained. It is done. Thus, in order to ensure high image quality and high durability, a toner having a sharp particle size distribution, that is, a toner having a small Dv / Dn is required.
However, the spherical toner having a small particle size and high particle size uniformity as compared with the pulverized toner cannot naturally obtain the desired small particle size and particle size uniformity unless the emulsification process conditions during emulsification are appropriate.

Conventionally, continuous emulsification equipment has been used as the emulsification process, and intensive studies have been conducted on the conditions of the continuous emulsification process.
For example, Patent Document 5 discloses a conventional continuous emulsification technique using mechanical shearing force. The emulsifier or disperser specified in Patent Document 5 has a plurality of stages of rotating teeth. However, the mixture of the colored resin melt and the aqueous medium is spotted at the shearing tooth point where the shearing force starts to be applied. However, it is not necessarily an ideal mixing ratio, and in that state, no matter what shearing force is required, no matter how many steps are added, emulsification occurs because there is spot variation in the mixing ratio of the colored resin melt and the aqueous medium. The toner particle diameter afterwards will vary greatly.
In order to emulsify the colored resin melt and the aqueous medium in an ideal mixing ratio, it is important to repeat microscopic dispersion and macroscopic mixing. As a construction method in line with this concept, there is a known batch emulsification method in which an emulsifier is installed in a tank and a colored resin melt and an aqueous medium are put into the tank to emulsify. In this batch method, microscopic dispersion by an emulsifier or disperser and macro mixing by liquid circulation in a tank are combined. However, it is disadvantageous when considering productivity.
Further, Patent Document 6 discloses a method of continuous emulsification and a method in which a dispersion that has passed through an emulsifier is passed several times using a circulation line. However, an emulsion dispersion in which the number of passes through the emulsifier is not uniform is disclosed. As a result, the particle size distribution tends to be broad.

  Therefore, in a method for producing a toner having an emulsification step, there is a strong demand for a method for efficiently producing a toner having a small particle size and a sharp particle size distribution and capable of obtaining a high-quality image with small equipment. Is not provided yet.

JP 2004-226669 A Japanese Patent No. 2666316 Japanese Patent Application Laid-Open No. 2002-6541 JP 2004-246345 A JP-A-9-311502 JP 2006-106724 A

  An object of the present invention is to solve various problems in the prior art and achieve the following objects. That is, the present invention provides (1) a method for producing a toner having a sharp particle size distribution necessary for obtaining a high-quality image, and (2) a toner having a sharp particle size distribution. It aims at providing the method which can be produced efficiently with small equipment.

Means for solving the problems are as follows. That is,
<1> Dissolve or disperse at least a binder resin, a colorant, and a release agent in an organic solvent, and supply an oil phase composed of the obtained solution or dispersion and an aqueous medium to a shearing unit. A method for producing a toner having an emulsification step of applying an shearing force to a mixed liquid of the oil phase and the aqueous medium to obtain an emulsion.
The mixture of the oil phase and the aqueous medium passes through the shearing means once, and before passing through the shearing means, the premixing means performs pre-mixing of the oil phase and the aqueous medium. A toner manufacturing method characterized by mixing.
<2> The method for producing a toner according to <1>, wherein the shearing unit is a thin film rotating emulsion machine.
<3> The toner production method according to any one of <1> to <2>, wherein the premixing unit is a rotor-stator type disperser.
<4> The method for producing a toner according to any one of <1> to <2>, wherein the premixing unit is a pipeline homomixer.
<5> The method for producing a toner according to any one of <1> to <2>, wherein the premixing unit is a static mixer.
<6> A binder resin precursor composed of a modified polyester resin is dissolved or dispersed in an organic solvent, and an oil phase composed of a solution or dispersion obtained, and the binder resin precursor in an organic solvent, A compound that is elongated or cross-linked is dissolved or dispersed, and an oil phase composed of the obtained solution or dispersion is emulsified and dispersed in an aqueous medium containing a dispersant to obtain an emulsified dispersion. The toner production method according to any one of <1> to <5>, wherein the binder resin precursor is subjected to an elongation reaction or a crosslinking reaction to remove an organic solvent.
<7> The method for producing a toner according to any one of <1> to <6>, wherein the binder resin is a polyester resin.
<8> The method for producing a toner according to <7>, wherein the content of the polyester resin in the binder resin is 50 to 100% by mass.
<9> The toner production method according to any one of <7> to <8>, wherein the polyester resin has a THF-soluble component having a weight average molecular weight of 1,000 to 30,000.
<10> The toner according to any one of <7> to <9>, wherein the polyester resin contains an acidic group, and the acid value of the polyester resin is 1.0 to 50.0 (KOHmg / g). It is a manufacturing method.
<11> The toner production method according to any one of <7> to <10>, wherein the glass transition point of the polyester resin is 35 to 65 ° C.
<12> The toner production method according to any one of <6> to <11>, wherein the binder resin precursor has a weight average molecular weight of 3,000 to 20,000.
<13> The method for producing a toner according to any one of <1> to <12>, wherein the obtained toner has an acid value of 0.5 to 40.0 (KOHmg / g).
<14> The method for producing a toner according to any one of <1> to <13>, wherein the obtained toner has a glass transition point of 40 to 70 ° C.
<15> The method for producing a toner according to any one of <1> to <14>, wherein the oil phase contains a modified layered inorganic mineral obtained by modifying at least part of ions between layers of the layered inorganic mineral with organic ions. It is.
<16> The toner production method according to any one of <1> to <15>, wherein the obtained toner has a volume average particle diameter (Dv) of 3.0 to 7.0 μm.
<17> The method for producing a toner according to any one of <1> to <16>, wherein the obtained toner has a volume average particle diameter (Dv) / number average particle diameter (Dn) of 1.00 to 1.20. It is.
<18> The method for producing a toner according to any one of <1> to <17>, wherein particles having a particle diameter of 2.0 μm or less are 20% by number or less in the obtained toner.
<19> The method for producing a toner according to any one of <1> to <18>, wherein the obtained toner has an average circularity of 0.93 to 0.97.
<20> A toner produced by the toner production method according to any one of <1> to <19>.

In the method for producing the toner of the present invention, at least a binder resin, a colorant, and a release agent are dissolved or dispersed in an organic solvent, and an oil phase composed of the obtained solution or dispersion and an aqueous medium are obtained. A method for producing toner having an emulsification step of supplying an emulsion to a shearing means and applying a shearing force to a mixture of the oil phase and the aqueous medium to obtain an emulsion, the mixing of the oil phase and the aqueous medium The number of times that the liquid passes through the shearing means is one, and before passing through the shearing means, the oil phase and the aqueous medium are premixed by the premixing means.
In the toner production method of the present invention, the number of times the mixed liquid of the oil phase and the aqueous medium passes through the shearing means is one (the number of passes is one), so that the number of passes is plural. Compared with the production method which is a single time, a uniform emulsified dispersion can be obtained, and therefore, a toner having a sharp particle size distribution can be obtained. Also, by setting the number of passes to one, it is possible to efficiently produce toner with a small facility without requiring a large-scale facility. On the other hand, the conventional manufacturing method in which the number of passes is plural requires a large-scale facility for circulating the emulsion after shearing, and a part of the emulsion is discharged after shearing in the first pass. The remaining emulsified liquid is circulated and further subjected to shearing in the second pass, and after the second pass shearing, a part of the emulsifying liquid is discharged again, and the third, fourth, and so on. Since it is subjected to a plurality of times of shearing, the number of times of passing through the shearing means varies depending on the toner particles, and the toner particle size distribution tends to be broad.
In the toner production method of the present invention, the oil phase and the aqueous medium are premixed by the premixing means before the shearing. The liquid mixture with the aqueous medium is ideally mixed, and therefore, even after one-time shearing, the emulsified liquid after shearing can be made more uniform, and variation in the toner particle diameter obtained can be eliminated. On the other hand, in the case where the pre-mixing is not performed, the mixed liquid of the oil phase and the aqueous medium is not necessarily an ideal mixing ratio at the shearing tooth point where the shearing force starts to be received. Even if the force is applied without inserting a hair, the emulsion after shearing is not uniform, and the variation in the toner particle size obtained becomes large.

The toner of the present invention is manufactured by the above-described toner manufacturing method of the present invention.
Since the toner of the present invention is manufactured by the above-described toner manufacturing method of the present invention, its particle size distribution is sharp, so that a high-quality image can be obtained.

  According to the present invention, various problems in the prior art can be solved. (1) To provide a method for producing a toner having a sharp particle size distribution necessary for obtaining a high-quality image; and (2 ) It is possible to provide a method capable of efficiently producing toner having a sharp particle size distribution with small equipment.

(Toner production method and toner)
In the method for producing the toner of the present invention, at least a binder resin, a colorant, and a release agent are dissolved or dispersed in an organic solvent, and an oil phase composed of the obtained solution or dispersion and an aqueous medium are obtained. A method for producing toner having an emulsification step of supplying an emulsion to a shearing means and applying a shearing force to a mixture of the oil phase and the aqueous medium to obtain an emulsion, the mixing of the oil phase and the aqueous medium The number of times that the liquid passes through the shearing means is one, and the oil phase and the aqueous medium are premixed by the premixing means before passing through the shearing means.
The toner of the present invention is manufactured by the above-described toner manufacturing method of the present invention.
Hereinafter, the details of the toner of the present invention will be clarified through the description of the toner production method of the present invention.

<< Emulsification process >>
First, the emulsification step in the toner production method of the present invention will be described.
In the emulsification step, the oil phase is dispersed (emulsified) in the aqueous medium by sequentially subjecting the oil phase and the aqueous medium to the following premixing and shearing. In the present invention, the emulsification is preferably performed continuously.

<Pre-mixing>
In the present invention, pre-mixing of the oil phase and the aqueous medium is performed before shearing described later. By performing premixing of the oil phase and the aqueous medium before shearing, the oil phase and the aqueous medium are brought into an ideal mixing ratio at the shearing tooth point where the shearing force starts to be received. Therefore, even after one-time shearing as will be described later, it is advantageous in that the emulsion after shearing can be made more uniform and variation in the toner particle size obtained can be eliminated.
On the other hand, in the case where the pre-mixing is not performed, the mixed liquid of the oil phase and the aqueous medium is not necessarily an ideal mixing ratio at a shearing tooth point where the shearing force starts to be received. Even if the force is applied without interposing, there is a problem that the emulsion after shearing is not uniform, and the variation in the toner particle size obtained is increased.

The premixing of the oil phase and the aqueous medium can be performed by supplying the oil phase and the aqueous medium to the premixing means, preferably continuously.
The pre-mixing means is not particularly limited and can be appropriately selected according to the purpose. Examples thereof include a rotor-stator type disperser such as Ebara Milder (manufactured by Taiheiyo Koki), a static mixer, a pipeline homomixer, and the like. Can be mentioned.

<Shear>
Moreover, in this invention, about the liquid mixture of the said oil phase and the said aqueous medium, the frequency | count of passing a shearing means shall be 1 time. By making the number of passes only once, it is advantageous in that a uniform emulsified dispersion can be obtained, and therefore a toner having a sharp particle size distribution can be produced. Further, it is advantageous in that the toner can be efficiently produced with a small facility without requiring a large-scale facility. In the present invention, as described above, since the oil phase and the aqueous medium are premixed before the shearing step, it is possible to obtain particles having a uniform particle size distribution even with one-pass emulsification. .
On the other hand, when a conventional circulation line is used and the number of passes of the shearing means is multipassed, an emulsified dispersion having an uneven number of passes of the shearing means is generated, and the particle size distribution of the obtained toner is There is a problem that it tends to be broad. A method of passing a plurality of shearing means in series is not desirable in terms of manufacturing space and cost.

The shearing can be performed by supplying a mixed liquid of the oil phase and the aqueous medium after the pre-mixing, preferably continuously to a shearing means. In addition, it is preferable that the said shearing means is connected with the exit part of the said pre-mixing means.
The shearing means is not particularly limited as long as it can impart a shearing force to the mixed liquid of the oil phase and the aqueous medium, and can be appropriately selected according to the purpose. Means capable of controlling the shear residence time by the amount of liquid, for example, T.W. K. It is preferable to use a thin film rotating type emulsifier such as Fillmix (manufactured by PRIMIX).

  A preferable emulsified state of the emulsion obtained after the shearing is a state in which the particles in the emulsion are stably present, and the particles dispersed in the emulsion remain in the system without coalescence even in the form of fine particles. When the shearing force in the emulsification process is insufficient, the particles in the system are difficult to be uniform. Conversely, when the shearing force is excessive, the emulsified and dispersed particles are likely to coalesce, and a broad particle size distribution is likely to occur.

<Oil phase>
The oil phase comprises a solution or dispersion obtained by dissolving or dispersing toner materials such as a binder resin, a colorant, and a release agent in an organic solvent. The method for obtaining the oil phase by dissolving or dispersing the toner material in an organic solvent is not particularly limited and may be appropriately selected from known methods according to the purpose.
As a toner material to be dissolved or dispersed in the oil phase, at least a binder resin, a release agent, and a colorant are used, and further, a binder resin precursor and a compound that extends or crosslinks with the binder resin precursor. It is preferable to use a modified layered inorganic mineral. Further, other toner materials may be used.
The oil phase does not need to contain all of the toner materials described above, and includes, for example, a combination of an oil phase containing a part of the toner material and an oil phase containing another toner material. There may be. Therefore, the mode for emulsifying and dispersing the oil phase in an aqueous medium to be described later is not limited to the mode in which the oil phase containing all of the toner materials described above is mixed and emulsified and dispersed in the aqueous medium. The oil phase containing a part of the toner material and the oil phase containing another toner material may be mixed in an aqueous medium and emulsified and dispersed.

-Organic solvent-
There is no restriction | limiting in particular as said organic solvent, Although it can select suitably according to the objective, Since removal is easy, it is preferable that a boiling point is less than 150 degreeC. 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, And methyl isobutyl ketone. Of these, toluene, xylene, benzene, methylene chloride, 1,2-dichloroethane, chloroform, carbon tetrachloride and the like are preferable, and ethyl acetate is particularly preferable. These may be used alone or in combination of two or more.

  The amount of the organic solvent used is not particularly limited and may be appropriately selected depending on the intended purpose. However, it is preferably 40 to 300 parts by weight, preferably 60 to 140 parts by weight with respect to 100 parts by weight of the toner material. It is more preferable that it is 80-120 mass parts.

  The organic solvent is preferably removed when the toner base particles are formed or after the toner base particles are formed.

-Binder resin-
The binder resin is not particularly limited and may be appropriately selected depending on the intended purpose. However, it is preferable to use a polyester resin that is a polycondensate of polyol (PO) and polycarboxylic acid (PC). . In addition, the said polyester resin may be used independently and may use 2 or more types together.

  There is no restriction | limiting in particular as said polyol (PO), According to the objective, it can select suitably, For example, diol (DIO), trihydric or more polyol (TO), diol (DIO), and trihydric or more polyol A mixture with (TO), etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, the diol (DIO) alone or a mixture of the diol (DIO) and a small amount of the trivalent or higher polyol (TO) is preferable.

Examples of the diol (DIO) include alkylene glycols, alkylene ether glycols, alicyclic diols, alkylene oxide adducts of alicyclic diols, bisphenols, alkylene oxide adducts of bisphenols, and the like.
The alkylene glycol is preferably one having 2 to 12 carbon atoms, such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, and the like. Can be mentioned. Examples of the alkylene ether glycol include diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, and the like. Examples of the alicyclic diol include 1,4-cyclohexanedimethanol and hydrogenated bisphenol A. Examples of the alkylene oxide adduct of the alicyclic diol include those obtained by adding an alkylene oxide such as ethylene oxide, propylene oxide, butylene oxide to the alicyclic diol. Examples of the bisphenols include bisphenol A, bisphenol F, and bisphenol S. Examples of the alkylene oxide adduct of the bisphenol include those obtained by adding an alkylene oxide such as ethylene oxide, propylene oxide, and butylene oxide to the bisphenol.
Among these, alkylene glycols having 2 to 12 carbon atoms, alkylene oxide adducts of bisphenols and the like are preferable, and alkylene oxide adducts of bisphenols, alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. Mixtures are particularly preferred.

The trivalent or higher polyol (TO) is preferably 3 to 8 or higher, for example, a trivalent or higher polyhydric aliphatic alcohol, a trivalent or higher polyphenol, a trivalent or higher polyphenol. And alkylene oxide adducts.
Examples of the trihydric or higher polyhydric aliphatic alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol and the like.
Examples of the trihydric or higher polyphenols include trisphenol PA, phenol novolak, cresol novolak, and the like.
Examples of the alkylene oxide adducts of trihydric or higher polyphenols include those obtained by adding alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide to the trihydric or higher polyphenols.

  The mixture mass ratio (DIO: TO) of the diol (DIO) and the trivalent or higher polyol (TO) in the mixture of the diol (DIO) and the trivalent or higher polyol (TO) is 100: 0.01-10 are preferable and 100: 0.01-1 are more preferable.

  There is no restriction | limiting in particular as said polycarboxylic acid (PC), Although it can select suitably according to the objective, For example, dicarboxylic acid (DIC), trivalent or more polycarboxylic acid (TC), dicarboxylic acid (DIC) ) And a tri- or higher valent polycarboxylic acid. These may be used individually by 1 type and may use 2 or more types together. Among these, dicarboxylic acid (DIC) alone or a mixture of DIC and a small amount of trivalent or higher polycarboxylic acid (TC) is preferable.

Examples of the dicarboxylic acid include alkylene dicarboxylic acid, alkenylene dicarboxylic acid, aromatic dicarboxylic acid, and the like.
Examples of the alkylene dicarboxylic acid include succinic acid, adipic acid, and sebacic acid.
As said alkenylene dicarboxylic acid, a C4-C20 thing is preferable, For example, a maleic acid, a fumaric acid, etc. are mentioned.
As said aromatic dicarboxylic acid, a C8-C20 thing is preferable, For example, a phthalic acid, an isophthalic acid, a terephthalic acid, naphthalene dicarboxylic acid etc. are mentioned.
Among these, alkenylene dicarboxylic acid having 4 to 20 carbon atoms and aromatic dicarboxylic acid having 8 to 20 carbon atoms are preferable.
The trivalent or higher polycarboxylic acid (TC) is preferably 3 to 8 or higher, and examples thereof include aromatic polycarboxylic acids.
The aromatic polycarboxylic acid preferably has 9 to 20 carbon atoms, and examples thereof include trimellitic acid and pyromellitic acid.
As the polycarboxylic acid (PC), the dicarboxylic acid (DIC), the trivalent or higher polycarboxylic acid (TC), and a mixture of the dicarboxylic acid (DIC) and the trivalent or higher polycarboxylic acid, Any acid anhydride or lower alkyl ester selected from can also be used.
Examples of the lower alkyl ester include methyl ester, ethyl ester, isopropyl ester and the like.
Mixing mass ratio (DIC: TC) of the dicarboxylic acid (DIC) and the trivalent or higher polycarboxylic acid (TC) in the mixture of the dicarboxylic acid (DIC) and the trivalent or higher polycarboxylic acid (TC) There is no restriction | limiting in particular, According to the objective, it can select suitably, For example, 100: 0.01-10 are preferable and 100: 0.01-1 are more preferable.

  The mixing ratio for the polycondensation reaction between the polyol (PO) and the polycarboxylic acid (PC) is not particularly limited and may be appropriately selected depending on the intended purpose. For example, in the polyol (PO) The equivalent ratio ([OH] / [COOH]) of the hydroxyl group [OH] to the carboxyl group [COOH] in the polycarboxylic acid (PC) is usually preferably 2/1 to 1/1. More preferably, it is 0.5 / 1 to 1/1, and particularly preferably 1.3 / 1 to 1.02 / 1.

  The weight-average molecular weight (Mw) of the polyester resin is preferably 1,000 to 30,000, preferably 1,500 to 15, 5,000 in terms of molecular weight distribution by GPC (gel permeation chromatography) soluble in tetrahydrofuran (THF). 000 is more preferable. When the weight average molecular weight (Mw) is less than 1,000, the heat resistant storage stability may be deteriorated. Therefore, the content of the component having the weight average molecular weight (Mw) of less than 1,000 is 8 masses. It is preferable that it is% -28 mass%. When the weight average molecular weight (Mw) exceeds 30,000, the low-temperature fixability is deteriorated, and the modification with the prepolymer is insufficient due to steric hindrance and the offset resistance may be deteriorated. On the other hand, when the weight average molecular weight (Mw) is in the more preferable range, the low temperature fixability is effectively exhibited while maintaining the heat resistant storage stability, and the offset resistance after modification by the prepolymer is imparted. This is advantageous in that it can.

The weight average molecular weight is measured, for example, by GPC (gel permeation chromatography) as follows.
First, the column is stabilized in a 40 ° C. heat chamber. At this temperature, tetrahydrofuran (THF) as a column solvent is allowed to flow at a flow rate of 1 ml per minute, and 50 to 200 μl of a tetrahydrofuran sample solution of a resin whose sample concentration is adjusted to 0.05 to 0.6 mass% is injected and measured. In measuring the molecular weight of the sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts. Examples of standard polystyrene samples for preparing the calibration curve include Pressure Chemical Co. Or the molecular weights made by Toyo Soda Kogyo Co., Ltd. are 6 × 10 ² , 2.1 × 10 ² , 4 × 10 ² , 1.75 × 10 ⁴ , 1.1 × 10 ⁵ , 3.9 × 10 ⁵ , 8.6 It is preferable to use those of × 10 ⁵ , 2 × 10 ⁶ , and 4.48 × 10 ⁶ and use at least about 10 standard polystyrene samples. As the detector, an RI (refractive index) detector can be used.

  As a glass transition point (Tg) of the said polyester resin, 35 to 65 degreeC is preferable. When the glass transition point is less than 35 ° C., the heat-resistant storage stability of the toner may be deteriorated, and when it exceeds 65 ° C., the low-temperature fixability may be insufficient. In addition, by coexistence with modified polyesters, such as a urea modified polyester resin mentioned later, even if a glass transition point is low, it shows the tendency for heat-resistant storage stability to be favorable.

The glass transition point (Tg) is measured with a Rigaku THRMOFLEX TG8110 manufactured by Rigaku Corporation under a temperature increase rate of 10 ° C./min.
An example of a method for measuring Tg will be outlined. A TG-DSC system TAS-100 manufactured by Rigaku Corporation is used as a device for measuring Tg.
First, about 10 mg of a sample is placed in an aluminum sample container, which is placed on a holder unit and set in an electric furnace. First, after heating from room temperature to 150 ° C. at a temperature rising rate of 10 ° C./min, the sample was allowed to stand at 150 ° C. for 10 min, the sample was cooled to room temperature and left for 10 min, and the temperature rising rate was again increased to 150 ° C. under a nitrogen atmosphere. DSC measurement is performed with heating at min. Tg is calculated from the contact point between the tangent line and the base line of the endothermic curve near Tg, using the analysis system in the TAS-100 system.

  The acid value of the polyester resin is preferably 1.0 to 50.0 (KOHmg / g), more preferably 1.0 to 30.0 (KOHmg / g), and 5.0 to 20.0 (KOHmg / g). More preferred is g). In general, by giving an acid value to the toner, it becomes easy to be negatively charged. Further, when fixing to paper, the affinity between the paper and the toner is good and the low-temperature fixability is improved. By adjusting the acid value of the polyester resin to 1.0 to 50.0 (KOHmg / g), particle size control by adding a basic compound, low temperature fixability, high temperature offset resistance, heat resistant storage stability, charging stability, etc. It is possible to improve the toner characteristics. That is, when the acid value exceeds 50.0 (KOHmg / g), the extension or crosslinking reaction of the modified polyester becomes insufficient, and the high temperature offset resistance may be affected, and 1.0 (KOHmg / g) If it is less than), the dispersion stabilizing effect due to the base compound at the time of production cannot be obtained, and the modified polyester tends to undergo elongation or crosslinking reaction, which may cause problems in production stability.

The acid value is measured by 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.
The acid value is specifically determined by the following procedure.
Measuring device: potentiometric automatic titrator DL-53 Titrator (manufactured by METTLER TOLEDO)
Electrode used: DG113-SC (manufactured by METTLER TOLEDO)
Analysis software: LabX Light Version 1.00.000
Calibration of the apparatus: Use a mixed solvent of 120 ml of toluene and 30 ml of ethanol.
Measurement temperature: 23 ° C
The measurement conditions are as follows.
・ Stirring conditions during titration
Speed [%] 25
Time [second] 15
・ Titration conditions
Titration solution CH3ONa
Concentration [mol / L] 0.1
Electrode DG115
Unit of measure mV
Add titrant before measurement
Additional amount [mL] 1.0
Waiting time [s] 0
Titration drop mode: Dynamic
dE (set) [mV] 8.0
dV (min) [mL] 0.03
dV (max) [mL] 0.5
Measurement mode: Equivalent measurement
dE [mV] 0.5
dt [s] 1.0
t (min) [s] 2.0
t (max) [s] 20.0
Stop measurement
Maximum dripping amount [mL] 10.0
End potential No
Equivalent display Yes

Measurement is performed under the following conditions in accordance with the measurement method described in JIS K0070-1992.
Sample preparation: 0.5 g of polyester (0.3 g for ethyl acetate-soluble component) is added to 120 ml of toluene and dissolved by stirring at room temperature (23 ° C.) for about 10 hours. Further, 30 ml of ethanol is added to prepare a sample solution.
The measurement can be calculated by the apparatus described above, and specifically, the calculation is performed as follows.
Titrate with a pre-standardized N / 10 caustic potash to alcohol solution, and determine the acid value from the consumption of the alcohol potash solution by the following calculation.
Acid value = KOH (ml) x N x 56.1 / sample weight (where N is a factor of N / 10 KOH)

  The hydroxyl value of the polyester resin is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g to 120 mgKOH / g, and still more preferably 20 mgKOH / g to 80 mgKOH / g. If the hydroxyl value is less than 5 mgKOH / g, it may be difficult to achieve both heat-resistant storage stability and low-temperature fixability.

The method for measuring the hydroxyl value is, for example, as follows.
Weigh accurately 0.5 g of sample into a 100 ml volumetric flask and add 5 ml of acetylating reagent correctly. Then, it is immersed in a bath at 100 ° C. ± 5 ° C. and heated. After 1-2 hours, the flask is removed from the bath, allowed to cool, water is added and shaken to decompose acetic anhydride. Next, in order to complete the decomposition, the flask is again heated in a bath for 10 minutes or more and allowed to cool, and then the wall of the flask is thoroughly washed with an organic solvent. This solution is subjected to potentiometric titration with an N / 2 potassium hydroxide ethyl alcohol solution using the electrode to determine the OH value (according to JIS K0070-1966).

Moreover, it is preferable that content of the said polyester resin is 50-100 mass% in the said binder resin.
In addition, there is no restriction | limiting in particular as binder resin other than the said polyester resin, According to the objective, it can select suitably.

-Release agent-
The release agent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples of waxes and waxes include plant waxes such as carnauba wax, cotton wax, wood wax, rice wax, and beeswax. And animal waxes such as lanolin, mineral waxes such as ozokerite and cercin, and petroleum waxes such as paraffin, microcrystalline and 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, and chlorinated hydrocarbon, and poly n-stearyl methacrylate and poly n-lauryl methacrylate which are low molecular weight crystalline polymer resins A crystalline polymer having a long alkyl group in the side chain, such as a polyacrylate homopolymer or copolymer (for example, a copolymer of n-stearyl acrylate-ethyl methacrylate, etc.) can also be used. Among these, paraffin wax, polyethylene wax, polypropylene wax, sazol wax and the like are preferable, and paraffin wax having a low melting point is particularly preferable in terms of improving low-temperature fixability.

  As the release agent, a low-melting-point release agent having a melting point of 50 to 120 ° C. is more effectively used as a release agent in the dispersion with the resin between the fixing roller and the toner interface. This is desirable in that it exhibits an effect against high temperature offset resistance without applying a release agent such as oil to the fixing roller. The melting point is the maximum endothermic peak measured by a differential scanning calorimeter (DSC).

  The release agent (wax) is preferably used so that it is contained in the toner in an amount of 1 to 10% by mass. If the content of the release agent in the toner is less than 1% by mass, the required releasability may not be obtained, and the fixability may be deteriorated. If it exceeds 10% by mass, problems such as filming occur. Sometimes.

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

  The colorant is preferably used so that the content in the toner is 1% by mass to 15% by mass, and more preferably 3% by mass to 10% by mass. When the content of the colorant in the toner is less than 1% by mass, a reduction in the coloring power of the toner is observed. When the content exceeds 15% by mass, poor dispersion of the pigment in the toner occurs, and This may lead to a decrease in the electrical characteristics of the toner.

The colorant may be used as a master batch combined with a resin.
Examples of the resin include modified and unmodified polyester resins, styrene such as polystyrene, poly p-chlorostyrene, and polyvinyltoluene, and substituted polymers thereof; styrene-p-chlorostyrene copolymer and styrene-propylene copolymer. Polymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-acrylic acid Octyl 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 copolymer, Styrene copolymers such as tylene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer; polymethyl methacrylate , Polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic or fat Examples thereof include cyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins and paraffin waxes, which can be used alone or in combination.

  The master batch can be obtained by mixing and kneading the resin and the colorant under a high shear force. At this time, an organic solvent can be used in order to enhance the interaction between the colorant and the resin. In addition, a so-called flushing method, which is a wet cake of colorant, is a method of mixing and kneading an aqueous paste containing water of a colorant together with a resin and an organic solvent, transferring the colorant to the resin side, and removing moisture and organic solvent components. Since it can be used as it is, it does not need to be dried and is preferably used. For mixing and kneading, a high shearing dispersion device such as a three-roll mill is preferably used.

-Binder resin precursor-
The binder resin precursor is made of a modified polyester resin. The modified polyester resin is preferably capable of reacting with a compound containing an active hydrogen group (an active hydrogen group-containing compound) described later.
The site capable of reacting with the active hydrogen group-containing compound in the modified polyester resin that can react with the active hydrogen group-containing compound (sometimes referred to as “prepolymer” in the present specification) is not particularly limited, Although it can select suitably from well-known substituents etc., an isocyanate group, an epoxy group, carboxylic acid, an acid chloride group etc. are mentioned, for example. These may be contained singly or in combination of two or more. Among these, an isocyanate group is particularly preferable.

Among the modified polyester resins, it is easy to adjust the molecular weight of the polymer component, and oil-less low-temperature fixing characteristics in dry toners, particularly good releasability and fixing even in the absence of a release oil application mechanism to a heating medium for fixing. From the viewpoint of securing properties, a urea bond-forming group-containing polyester resin (RMPE) is particularly preferable.
As said urea bond production | generation group, an isocyanate group etc. are mentioned, for example. When the urea bond generating group in the urea bond generating group-containing polyester resin (RMPE) is the isocyanate group, the urea bond generating group-containing polyester resin (RMPE) includes an isocyanate group-containing polyester prepolymer (A) and the like. It is particularly preferable.

  There is no restriction | limiting in particular as frame | skeleton of the said isocyanate group containing polyester prepolymer (A), According to the objective, it can select suitably, For example, it is a polycondensate of a polyol (PO) and polycarboxylic acid (PC). A product obtained by reacting a certain active hydrogen group-containing polyester with polyisocyanate (PIC), a polycondensate of the polyol (PO) and the polycarboxylic acid (PC), and a cyclic ester are subjected to ring-opening addition polymerization and active hydrogen groups. Examples of the polyester include a polyester obtained by reacting with polyisocyanate (PIC).

  For example, polyol (PO) and polycarboxylic acid (PC) are heated to 150-280 ° C. in the presence of a known esterification catalyst such as tetrabutoxytitanate, dibutyltin oxide, etc. To obtain a polyester having a hydroxyl group. Next, this is reacted with polyisocyanate (PIC) at 40 to 140 ° C. to obtain an isocyanate group-containing polyester prepolymer (A).

  Examples of the active hydrogen group of the active hydrogen group-containing 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.

There is no restriction | limiting in particular as said polyol (PO), For example, the polyol (PO) similar to what was described by the item of the said binder resin can be used.
There is no restriction | limiting in particular as said polycarboxylic acid (PC), For example, the polycarboxylic acid (PC) similar to what was described in the item of the said binder resin can be used.
Moreover, there is no restriction | limiting in particular also as a mixing ratio at the time of carrying out the polycondensation reaction of the said polyol (PO) and polycarboxylic acid (PC), The preferable mixing ratio is as having described in the item of the said binder resin. .

  There is no restriction | limiting in particular as content in the said isocyanate group containing polyester prepolymer (A) of the said polyol (PO), Although it can select suitably according to the objective, For example, 0.5 mass%-40 mass% Is preferable, 1% by mass to 30% by mass is more preferable, and 2% by mass to 20% by mass is particularly preferable. When the content is less than 0.5% by mass, the hot offset resistance deteriorates, and it may be difficult to achieve both the heat-resistant storage stability and the low-temperature fixability of the toner, and exceeds 40% by mass. In some cases, the low-temperature fixability may deteriorate.

  There is no restriction | limiting in particular as said polyisocyanate (PIC), Although it can select suitably according to the objective, For example, aliphatic polyisocyanate, alicyclic polyisocyanate, aromatic diisocyanate, araliphatic diisocyanate, isocyanurate And those blocked with phenol derivatives, oximes, caprolactams, and the like. Examples of the aliphatic polyisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, trimethylhexane diisocyanate, Examples include tetramethylhexane diisocyanate. Examples of the alicyclic polyisocyanate include isophorone diisocyanate and cyclohexylmethane diisocyanate. Examples of the aromatic diisocyanate include tolylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, diphenylene-4,4′-diisocyanate, 4,4′-diisocyanato-3,3′-dimethyldiphenyl, 3- Examples thereof include methyldiphenylmethane-4,4′-diisocyanate, diphenyl ether-4,4′-diisocyanate and the like. Examples of the araliphatic diisocyanate include α, α, α ′, α′-tetramethylxylylene diisocyanate. Examples of the isocyanurates include tris-isocyanatoalkyl-isocyanurate and triisocyanatocycloalkyl-isocyanurate.

As a mixing ratio when the polyisocyanate (PIC) and the active hydrogen group-containing polyester resin (for example, a hydroxyl group-containing polyester resin) are reacted, the isocyanate group [NCO] in the polyisocyanate (PIC) and the hydroxyl group-containing component are used. The mixing equivalent ratio ([NCO] / [OH]) with the hydroxyl group [OH] in the polyester resin is usually preferably 5/1 to 1/1, and 4/1 to 1.2 / 1. Is more preferable, and 2.5 / 1 to 1.5 / 1 is particularly preferable.
When the isocyanate group [NCO] exceeds 5, the low-temperature fixability may be deteriorated. When it is less than 1, when the modified polyester is used, the urea content in the ester becomes low and the offset resistance deteriorates. There are things to do.
There is no restriction | limiting in particular as content in the said isocyanate group containing polyester prepolymer (A) of the said polyisocyanate (PIC), Although it can select suitably according to the objective, For example, 0.5 mass%-40 mass % Is preferable, 1% by mass to 30% by mass is more preferable, and 2% by mass to 20% by mass is still more preferable. When the content is less than 0.5% by mass, the hot offset resistance is deteriorated, and it may be difficult to achieve both heat-resistant storage stability and low-temperature fixability. When the content exceeds 40% by mass, Low temperature fixability may deteriorate.

  The average number of isocyanate groups contained in one molecule of the isocyanate group-containing polyester prepolymer (A) is preferably 1 or more, more preferably 1.5 to 3, and more preferably 1.8 to 2.5. When the average number of the isocyanate groups is less than 1, the molecular weight of the polyester resin (RMPE) modified with the urea bond-forming group is lowered, and the hot offset resistance may be deteriorated.

The weight average molecular weight (Mw) of the binder resin precursor is preferably 3,000 to 20,000 in terms of molecular weight distribution by GPC (gel permeation chromatography) soluble in tetrahydrofuran (THF). When the weight average molecular weight (Mw) is less than 3,000, the heat resistant storage stability may be deteriorated, and when it exceeds 20,000, the low temperature fixability may be deteriorated.
Measurement of the molecular weight distribution by gel permeation chromatography (GPC) can be performed in the same manner as described above.

  The mass ratio of the binder resin precursor to the binder resin is not particularly limited and can be appropriately selected depending on the purpose.

-Compound that stretches or crosslinks with binder resin precursor-
Examples of the compound that extends or crosslinks with the binder resin precursor include compounds containing active hydrogen groups (active hydrogen group-containing compounds) that can react with the modified polyester resin.
The active hydrogen group-containing compound acts as an elongation agent, a crosslinking agent, or the like when the modified polyester resin undergoes an elongation reaction, a crosslinking reaction, or the like in the emulsification step of the oil phase and the aqueous medium.

The active hydrogen group-containing compound is not particularly limited as long as it has an active hydrogen group, and can be appropriately selected according to the purpose. For example, the modified polyester resin is an isocyanate group-containing polyester prepolymer (A ), The amines (B) are preferred in that they can be polymerized by a reaction such as an elongation reaction or a crosslinking reaction with the isocyanate group-containing polyester prepolymer (A).
There is no restriction | limiting in particular as said active hydrogen group, According to the objective, it can select suitably, For example, a hydroxyl group (alcoholic hydroxyl group or phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, an alcoholic hydroxyl group is particularly preferable.

The amines (B) are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include diamine (B1), trivalent or higher polyamine (B2), amino alcohol (B3), and amino mercaptan. (B4), amino acid (B5), and those obtained by blocking the amino groups of B1 to B5 (B6). These may be used individually by 1 type and may use 2 or more types together. Among these, diamine (B1), a mixture of diamine (B1) and a small amount of a trivalent or higher polyamine (B2) is particularly preferable.
Examples of the diamine (B1) include aromatic diamines, alicyclic diamines, and aliphatic diamines. Examples of the aromatic diamine include phenylenediamine, diethyltoluenediamine, 4,4′diaminodiphenylmethane, and the like. Examples of the alicyclic diamine include 4,4′-diamino-3,3′dimethyldicyclohexylmethane, diaminecyclohexane, and isophoronediamine. Examples of the aliphatic diamine include ethylene diamine, tetramethylene diamine, and hexamethylene diamine.
Examples of the trivalent or higher polyamine (B2) include diethylenetriamine and triethylenetetramine.
Examples of the amino alcohol (B3) include ethanolamine and hydroxyethylaniline.
Examples of the amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan.
Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid.
Examples of the block (B6) in which the amino group of B1 to B5 is blocked include, for example, a ketimine obtained from any of the amines (B1) to (B5) and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.) Compounds, oxazolyzone compounds, and the like.

  In addition, a reaction terminator can be used to stop the elongation reaction, the crosslinking reaction and the like between the active hydrogen group-containing compound and the modified polyester resin. Use of the reaction terminator is preferable in that the molecular weight can be controlled within a desired range. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.) or those blocked (ketimine compounds).

As a mixing ratio of the amines (B) and the isocyanate group-containing polyester prepolymer (A), the isocyanate group [NCO] in the isocyanate group-containing modified polyester (A) and the amines (B) The mixing equivalent ratio ([NCO] / [NHx]) of the amino group [NHx] is preferably 1/2 to 2/1, more preferably 1 / 1.5 to 1.5 / 1. A ratio of 1 / 1.2-1.2 / 1 is particularly preferable.
If the mixing equivalent ratio ([NCO] / [NHx]) is less than ½, the low-temperature fixability may decrease. If it exceeds 2/1, the molecular weight of the modified polyester resin will be low. The hot offset resistance may be deteriorated.

In the emulsification step or the like, the polyester (UMPE) modified with a urea bond can be obtained by reacting the isocyanate group-containing polyester prepolymer (A) with an amine (B) at 0 to 140 ° C.
The number average molecular weight of the urea-modified polyester (UMPE) is usually preferably from 1,000 to 10,000, and more preferably from 1,500 to 6,000.
The weight average molecular weight of the urea-modified polyester (UMPE) is usually preferably 10,000 or more, more preferably 20,000 to 10,000,000 and even more preferably 30,000 to 1,000,000. When the weight average molecular weight is less than 10,000, the hot offset resistance may be deteriorated.

  In addition, when making polyisocyanate (PIC) react in order to obtain an isocyanate group-containing polyester prepolymer (A) and when reacting an isocyanate group-containing polyester prepolymer (A) with amines (B). If necessary, a solvent can also be used. Usable solvents include aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.), ethers And those inert to isocyanates (PIC) such as tetrahydrofuran (such as tetrahydrofuran).

  Modified polyesters such as urea-modified polyester obtained by reacting the isocyanate group-containing polyester prepolymer (A) with the amines (B) are easy to adjust the molecular weight of the polymer component, and are dry toners, particularly oilless low-temperature fixing. It is convenient to ensure the characteristics (wide releasability and fixability without a release oil application mechanism to the fixing heating medium). Particularly, a polyester prepolymer whose end is modified with urea can suppress adhesion to a heating medium for fixing while maintaining high fluidity and transparency in the fixing temperature range of the unmodified polyester resin itself.

  The urea-modified polyester (UMPE) may contain a urethane bond as well as a urea bond in the polyester. The molar ratio between the urea bond content and the urethane bond content is usually preferably 100/0 to 10/90, more preferably 80/20 to 20/80, and still more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance may be deteriorated.

  In the toner, at least a part of the modified polyester resin such as urea-modified polyester (UMPE) and the polyester resin (PE) are preferably compatible in terms of low-temperature fixability and hot offset resistance. Accordingly, the polyester component of the urea-modified polyester (UMPE) and the polyester component of the polyester resin (PE) are preferably similar in composition. The mass ratio of the urea-modified polyester (UMPE) and the polyester resin (PE) in the toner is usually preferably from 5/95 to 80/20, more preferably from 5/95 to 30/70. 25/75 is more preferable, and 7/93 to 20/80 is particularly preferable. When the mass ratio of the urea-modified polyester (UMPE) is less than 5%, the hot offset resistance is deteriorated, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

-Modified layered inorganic mineral-
The modified layered inorganic mineral refers to a material in which at least a part of ions between layers of the layered inorganic mineral is modified with organic ions. Here, the “layered inorganic mineral” means a structure in which inorganic mineral layers having a thickness of several nanometers are stacked almost in parallel by weak forces such as van der Waals force and electrostatic force, and coordinate or absorb a solvent between layers. It is an inorganic mineral that exhibits the property of swelling or cleaving. “Denature” means introducing organic ions into ions existing between the layers, and in a broad sense, means intercalation.

  As the layered inorganic mineral, for example, smectite group (montmorillonite, saponite, etc.), kaolin group (kaolinite, etc.), magadiite, kanemite, etc. are known.

  As the modified layered inorganic mineral obtained by modifying at least part of the ions between the layers of the layered inorganic mineral with organic ions, those having a smectite basic crystal structure modified with an organic cation are preferable. Moreover, a metal anion can be introduce | transduced by substituting a part of bivalent metal of the said layered inorganic mineral for a trivalent metal. However, since the hydrophilic property is high when the metal anion is introduced, a modified layered inorganic mineral obtained by modifying at least a part of the metal anion with an organic anion is preferable.

  Examples of the organic ion modifier for modifying at least part of the ions between the layers of the layered inorganic mineral with organic ions include quaternary alkyl ammonium salts, phosphonium salts, imidazolium salts, and the like. Of these, quaternary alkyl ammonium salts are preferred. Examples of the quaternary alkyl ammonium include trimethyl stearyl ammonium, dimethyl stearyl benzyl ammonium, dimethyl octadecyl ammonium, oleyl bis (2-hydroxyethyl) methyl ammonium, and the like.

  Examples of the organic ion modifier include branched, unbranched, or cyclic alkyl (1 to 44 carbon atoms), alkenyl (1 to 22 carbon atoms), alkoxy (8 to 32 carbon atoms), hydroxyalkyl (2 carbon atoms). To 22), sulfates having ethylene oxide, propylene oxide and the like; sulfonates, carboxylates, phosphates and the like. Among these, carboxylic acids having an ethylene oxide skeleton are preferable.

By modifying at least part of the ions between the layers of the layered inorganic mineral with organic ions to form a modified layered inorganic mineral, it has moderate hydrophobicity, so the oil phase has a non-Newtonian viscosity and the toner is deformed can do. At this time, the content of the modified layered inorganic mineral in the toner material is preferably 0.05 to 2% by mass.
The modified layered inorganic mineral is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include montmorillonite, bentonite, hectorite, attapulgite, sepiolite, and mixtures thereof. Among these, organically modified montmorillonite and bentonite are preferable because they can easily adjust the viscosity without affecting the toner characteristics and can be added in a small amount.

Among the modified layered inorganic minerals, commercially available modified layered inorganic minerals in which at least some of the ions between layers are modified with organic cations include, for example, Bentone 3, Bentone 38, Bentone 38V (above, manufactured by Leox), thixogel QUATANIUM 18 bentonite such as VP (manufactured by United catalyst), Clayton 34, Clayton 40, Clayton XL (manufactured by Southern Clay, Inc.); Bentone 27 (manufactured by Leox), Thixogel LG (manufactured by United catalyst), Clayton AF, Stearalkonium bentonites such as Clayton APA (above, Southern Clay), etc .; Quaternium 18 / Benzalkonium bentonites such as Clayton HT, Clayton PS (above, Southern Clay) etc. It is. Among these, Clayton AF and Clayton APA are preferable.
Further, among the modified layered inorganic minerals, DHT-4A (manufactured by Kyowa Chemical Industry Co., Ltd.) is represented by the following general formula (1) as a modified layered inorganic mineral obtained by modifying at least some of the ions between layers with an organic anion. Those modified with an organic anion are preferred.
^{_{R 1 (OR 2) n OSO}} 3 M ··· formula (1)
However, the general formula (1), ^{R 1} is an alkyl group of 13 carbon atoms, ^{R 2} represents an alkylene group having 2 to 6 carbon atoms. n represents an integer of 2 to 10, and M represents a monovalent metal element.
Examples of the organic anion represented by the following general formula (1) include Hytenol 330T (Daiichi Kogyo Seiyaku Co., Ltd.).

  As described above, a modified layered inorganic mineral in which at least a part of ions between layers of the layered inorganic mineral is modified with an organic ion has an appropriate hydrophobicity, and therefore tends to be present at the droplet interface. Can be unevenly distributed on the surface of the toner and exhibit charging properties.

<Aqueous medium>
As the aqueous medium, water alone may be used, but a solvent miscible with water may be used in combination. Examples of miscible solvents include alcohol (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.) and the like.

  The amount of the aqueous medium used relative to 100 parts by mass of the oil phase is preferably 50 to 2,000 parts by mass, and more preferably 100 to 1,000 parts by mass. When the amount used is less than 50 parts by mass, the dispersed state of the oil phase is poor, and toner particles having a predetermined particle size may not be obtained, and when it exceeds 2,000 parts by mass, it is not economical.

Moreover, a dispersing agent can also be used for the said aqueous medium as needed. Use of the dispersant is advantageous in that the particle size distribution of the toner becomes sharp and the dispersion is stable.
Examples of the dispersant include a surfactant, an inorganic fine particle dispersant, and a polymer fine particle dispersant.

Examples of the surfactant include anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, and phosphate esters, alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, and amine salts such as imidazoline. Type, quaternary ammonium salt type cationic surfactant such as alkyltrimethylammonium salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkylisoquinolinium salt, benzethonium chloride, fatty acid amide derivative, Amphoteric boundaries such as nonionic surfactants such as polyhydric alcohol derivatives such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl-N, N-dimethylammonium betaine Active agents.
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- [omega-fluoroalkyl (C6-C11 ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [omega-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) -Fluorooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Is mentioned.
As a trade name, for example, 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 (Daikin Kogyo Co., Ltd.), MegaFuck F-110, F-120, F-113, F-191, F-812, F-833 (Dainippon Ink Co., Ltd.), 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).
Examples of cationic surfactants include aliphatic primary, secondary or secondary amine acids having a fluoroalkyl group, aliphatic quaternary ammonium salts such as perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, benza Luconium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (Asahi Glass), Florard FC-135 (Sumitomo 3M), Unidyne DS-202 (Daikin Kogyo) Megafac F-150, F-824 (manufactured by Dainippon Ink, Inc.), Xtop EF-132 (manufactured by Tochem Products), and Footgent F-300 (manufactured by Neos).

  Moreover, tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, hydroxyapatite, etc. can be used as the inorganic fine particle dispersant.

  The polymer fine particle dispersant was also confirmed to have the same effect as the inorganic fine particle dispersant. For example, MMA polymer fine particles 1 μm and 3 μm, styrene fine particles 0.5 μm and 2 μm, styrene-acrylonitrile fine particle polymer 1 μm, (PB-200H (manufactured by Kao) SGP (Soken), Technopolymer SB (Sekisui Plastics), SGP- 3G (Soken) Micropearl (Sekisui Fine Chemical)).

  Further, as a dispersant that can be used in combination with the inorganic fine particle dispersant and the polymer fine particle 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 β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, γ-hydroxypropyl methacrylate, 3-acrylate Chloro-2-hydroxypropyl, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate, 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, etc., or esters of compounds containing vinyl alcohol and carboxyl groups, such as Pinyl acetate, pinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, pinyl pyridine, vinyl pyrrolidone, vinyl imidazole, ethylene imine, etc. Homopolymers or copolymers such as those having nitrogen atoms or heterocyclic rings thereof, polyoxyethylene, polyoxypropylene, polymers Oxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene nonylphenyl Polyoxyethylenes such as esters, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.

  In the emulsification step, the oil phase is preferably emulsified in the aqueous medium to prepare an emulsion, and at the same time, the isocyanate group-containing polyester prepolymer (A) and amines (B) are reacted. This reaction is accompanied by crosslinking or elongation of molecular chains. The reaction time is selected depending on the reactivity between the isocyanate group structure of the isocyanate group-containing 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.

  Hereinafter, steps other than the emulsification step in the toner production method of the present invention will be described. There is no restriction | limiting in particular about processes other than an emulsification process, According to a well-known method, it can carry out suitably.

<< Washing-drying process >>
After the emulsification step, for example, toner base particles can be obtained by removing the organic solvent from the emulsified liquid, washing and drying according to a known method.
In order to remove the organic solvent, for example, the temperature of the entire system is gradually increased in a laminar stirring state, and after strong stirring is performed in a certain temperature range, toner base particles can be produced by performing solvent removal. . When a dispersion stabilizer that is soluble in an acid or alkali such as calcium phosphate is used, the calcium phosphate is dissolved from the toner base particles by a method such as dissolving the calcium phosphate with an acid such as hydrochloric acid and washing with water. Can be removed. In addition, it can be removed by an operation such as enzymatic degradation.
In addition, by giving strong agitation in the step 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.

<< Toner Formation Process >>
The toner base particles obtained in the washing-drying step can form a toner according to a known method.
For example, a toner can be formed by implanting a charge control agent into the obtained toner base particles and then externally adding inorganic fine particles (external additives) such as silica fine particles and titanium oxide fine particles.
The injection of the charge control agent and the external addition of the inorganic fine particles (external additive) can be performed by, for example, a known method using a mixer or the like.

-Charge control agent-
The charge control agent is not particularly limited and may be appropriately selected from known ones according to the purpose. Examples thereof include nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, and molybdate chelate pigments. Rhodamine dyes, alkoxy amines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus simple substances or compounds, tungsten simple substances or compounds, fluorine activators, salicylic acid metal salts, and Examples thereof include metal salts of salicylic acid derivatives. Specifically, Bontron 03 of nigrosine dye, Bontron P-51 of quaternary ammonium salt, Bontron S-34 of metal-containing azo dye, E-82 of oxynaphthoic acid metal complex, E of salicylic acid metal complex -84, phenolic condensate E-89 (above, Orient Chemical Industries), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical Co., Ltd.), quaternary Copy charge PSY VP2038 of ammonium salt, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (above, manufactured by Hoechst), LRA-901, LR- which is a boron complex 147 (manufactured by Nippon Carlit), copper phthalocyanine, perylene, quinaclide , Azo pigments, sulfonate group, carboxyl group, and polymer compounds having a functional group such as a quaternary ammonium salt.

  Although the usage-amount of the said charge control agent cannot be prescribed | regulated unconditionally, 0.1 mass-10 mass parts are preferable with respect to 100 mass parts of said binder resin, for example, 0.2 mass parts-5 mass parts Is more preferable. If the amount used is less than 0.1 parts by mass, the charge controllability may not be obtained. If the amount used exceeds 10 parts by mass, the chargeability of the toner becomes too large, reducing the effect of the main charge control agent. As a result, the electrostatic attractive force with the developing roller increases, which may lead to a decrease in developer fluidity and a decrease in image density.

  The charge control agent may be used by melt kneading with a masterbatch and resin at the stage of preparing the oil phase, or may be used by adding it when dissolved and dispersed in an organic solvent. Good.

-Inorganic fine particles (external additives)-
The inorganic fine particles are not particularly limited and may be appropriately selected depending on the purpose. For example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, Tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride, etc. Is mentioned.
Among these, it is preferable to use hydrophobic silica fine particles and hydrophobic titanium oxide fine particles in combination. In particular, when stirring and mixing is performed using an average particle size of both fine particles of 50 mμ or less, the electrostatic force and van der Waals force with the toner are remarkably improved, so that a desired charge level is obtained. This is advantageous in that, even when stirring and mixing inside the developing machine, a fluidity-imparting agent is not detached from the toner, a good image quality that does not cause firefly and the like is obtained, and further, the residual toner is reduced. It is.
Titanium oxide fine particles are excellent in environmental stability and image density stability, but have a tendency to deteriorate the charge rising characteristics. Therefore, if the amount of titanium oxide fine particles used is greater than the amount of silica fine particles used, the side effect is greatly affected. It is possible to become. However, when the amount of the hydrophobic silica fine particles and the hydrophobic titanium oxide fine particles used is in the range of 0.3 to 1.5% by mass, the charge rise characteristics are not greatly impaired, and the desired charge rise characteristics can be obtained. Even if it is repeated, it is advantageous in that stable image quality can be obtained and toner blowing can be suppressed.

The primary particle diameter of the inorganic fine particles is preferably 5 mμ to 2 μm, and particularly preferably 5 mμ to 500 mμ. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g.
The inorganic fine particles are preferably used so that the content in the toner is 0.01 to 5% by mass, and particularly preferably 0.01 to 2.0% by mass.

  By the toner production method of the present invention as described above, a toner having a small particle size and a sharp particle size distribution can be efficiently obtained with a small facility.

<< Toner >>
The characteristics of the toner of the present invention obtained by the above-described method for producing the toner of the present invention are shown below.

-Volume average particle diameter, Volume average particle diameter / Number average particle diameter-
The volume average particle diameter (Dv) of the toner is preferably 3.0 to 7.0 μm. 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. Further, when the volume average particle size is smaller than the preferred range, in the case of a two-component developer, the toner is fused to the surface of the carrier during a long period of stirring in the developing device, and the charging ability of the carrier is reduced. When it is used, toner filming on the developing roller and toner fusion to a member such as a blade for thinning the toner are likely to occur. These phenomena are greatly related to the content of fine powders. In particular, when the number of particles having a size of 2.0 μm or less exceeds 20% by number, it becomes a hindrance when the adhesion to a carrier or the stability of charging at a high level is achieved. On the other hand, when the volume average particle diameter of the toner is larger than the above preferable range, it becomes difficult to obtain a high-resolution and high-quality image, and the toner in the developer is balanced. In many cases, the fluctuation of the particle size of the particles becomes large.

The ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) of the toner is preferably 1.00 to 1.30, and preferably 1.00 to 1.20. It is more preferable that
When the Dv / Dn exceeds 1.30, the particle size variation of individual toner particles is large, and the toner behavior varies during development and the like, and the reproducibility of minute dots is impaired. , High-quality images may not be obtained. On the other hand, when the Dv / Dn is within the preferable range, it is advantageous in that a high-resolution and high-quality toner can be obtained. Furthermore, in the case of a two-component developer, even if a long-term balance of the toner is performed, fluctuations in the particle size of the toner in the developer are reduced, and good and stable developability even with long-term stirring in the developing device. Is possible.

  The toner preferably has 20% by number or less of particles having a particle size of 2.0 μm or less.

  Here, the average particle diameter and the particle size distribution of the toner can be measured by a car Coulter counter method. Examples of the measuring device for the particle size distribution of toner particles include Coulter Counter TA-II and Coulter Multisizer II (both manufactured by Coulter). For example, using Coulter Counter TA-II, the particle size distribution can be measured by connecting an interface (Nichiken Giken) that outputs number distribution and volume distribution and PC9801 personal computer (manufactured by NEC).

An example of a method for measuring the average particle size and the particle size distribution will be 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 the aperture. Volume distribution and number distribution are calculated.
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. The volume-based volume average particle diameter (Dv) obtained from the volume distribution and the number average particle diameter (Dn) obtained from the number distribution and the ratio Dv / Dn are obtained.

-Circularity, average circularity-
Here, the relationship between the toner shape and transferability will be described. When using a full-color copier that transfers images with multi-color development, the amount of toner on the photoconductor increases compared to the case of one-color black toner used in black-and-white copiers. It is difficult to improve transfer efficiency. In addition, when ordinary irregular toner is used, a shearing force or friction between the photosensitive member and the cleaning member, between the intermediate transfer member and the cleaning member, and / or between the photosensitive member and the intermediate transfer member. Due to the force, toner fusing or filming occurs on the surface of the photoreceptor or the intermediate transfer member, and the transfer efficiency tends to deteriorate. When generating a full-color image, it is difficult to transfer the four-color toner images uniformly. Furthermore, when an intermediate transfer member is used, problems are likely to occur in terms of color unevenness and color balance, and high-quality full-color images are stabilized. Output is not easy.

  From the viewpoint of the balance between blade cleaning and transfer efficiency, the toner having a circularity of 0.950 or less is 20 to 80% by number of all toner particles, so that both cleaning and transferability can be achieved. Cleaning and transferability are greatly related to the material of the blade and how to apply the blade, and transfer also varies depending on the process conditions, so that the design according to the process can be performed within the above range. However, when particles having a toner circularity of 0.950 or less fall below 20% by number of all toner particles, cleaning with a blade becomes difficult. On the other hand, when the number of particles having a circularity of 0.950 or less exceeds 80% by number of all toner particles, the aforementioned transferability is deteriorated. This phenomenon is caused by excessively deformed toner shape, so that toner movement during transfer (photosensitive member surface to transfer paper, photosensitive member surface to intermediate transfer belt, first intermediate transfer belt to second intermediate transfer belt) , Etc.) are not smooth, and the toner particles vary in behavior, so that uniform and high transfer efficiency cannot be obtained. In addition, unstable charging and brittleness of particles begin to appear. Furthermore, it becomes a fine phenomenon in the developer, which causes a decrease in the durability of the developer. For this reason, it is preferable that the number of particles having a toner circularity of 0.950 or less is 20 to 80% by number of all toner particles.

  The average circularity of the toner is preferably 0.93 to 0.97.

Here, the circularity and average circularity of the toner can be measured by a flow type particle image analyzer FPIA-2100 (manufactured by Toa Medical Electronics Co., Ltd.).
As a specific measuring method, for example, 0.1 to 0.5 ml of a surfactant, preferably alkylbenzene sulfonate is added as a dispersant in 100 to 150 ml of water in which impure solids have been removed in advance. Further, about 0.1 to 0.5 g of a measurement sample is added. The suspension in which the sample is dispersed is obtained by performing dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and measuring the shape and distribution of the toner with the above apparatus at a dispersion concentration of 3000 to 10,000 / μl. .

The hydroxyl value of the toner is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g to 120 mgKOH / g, and still more preferably 20 mgKOH / g to 80 mgKOH / g. If the hydroxyl value is less than 5 mgKOH / g, it may be disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.
The acid value of the toner is preferably 0.5 mgKOH / g to 40.0 mgKOH / g, more preferably 5.0 mgKOH / g to 30.0 mgKOH / g, and further preferably 15.0 mgKOH / g to 28.0 mgKOH / g. preferable. By giving the acid value within the above preferred range, it tends to be negatively charged, and the affinity with paper at the time of fixing is increased, and the fixing power is increased.

Here, the acid value (AV) and the hydroxyl value (OHV) in the toner are specifically determined by the following procedure.
Measuring device: potentiometric automatic titrator DL-53 Titrator (manufactured by METTLER TOLEDO)
Electrode used: DG113-SC (manufactured by METTLER TOLEDO)
Analysis software: LabX Light Version 1.00.000
Calibration of the apparatus: Use a mixed solvent of 120 ml of toluene and 30 ml of ethanol.
Measurement temperature: 23 ° C
The measurement conditions are as follows.
・ Stirring conditions during titration
Speed [%] 25
Time [second] 15
・ Titration conditions
Titration solution CH3ONa
Concentration [mol / L] 0.1
Electrode DG115
Unit of measure mV
Add titrant before measurement
Additional amount [mL] 1.0
Waiting time [s] 0
Titration drop mode: Dynamic
dE (set) [mV] 8.0
dV (min) [mL] 0.03
dV (max) [mL] 0.5
Measurement mode: Equivalent measurement
dE [mV] 0.5
dt [s] 1.0
t (min) [s] 2.0
t (max) [s] 20.0
Stop measurement
Maximum dripping amount [mL] 10.0
End potential No
Equivalent display Yes

The acid value can be measured under the following conditions based on the measurement method described in JIS K0070-1992.
Sample preparation: 0.5 g of toner (0.3 g for ethyl acetate-soluble component) is added to 120 ml of toluene and dissolved by stirring for about 10 hours at room temperature (23 ° C.). Furthermore, 30 ml of ethanol is added to prepare a sample solution.
The measurement can be calculated by the apparatus described above, and specifically, the calculation is performed as follows.
Titrate with a pre-standardized N / 10 caustic potash to alcohol solution, and determine the acid value from the consumption of the alcohol potash solution by the following calculation.
Acid value = KOH (ml) x N x 56.1 / sample weight (where N is a factor of N / 10 KOH)

The hydroxyl value can be measured under the following conditions based on the measurement method described in JIS K0070-1966.
Weigh accurately 0.5 g of sample into a 100 ml volumetric flask and add 5 ml of acetylating reagent correctly. Then, it is immersed in a bath at 100 ° C. ± 5 ° C. and heated. After 1-2 hours, the flask is removed from the bath, allowed to cool, water is added and shaken to decompose acetic anhydride. Next, in order to complete the decomposition, the flask is again heated in a bath for 10 minutes or more and allowed to cool, and then the wall of the flask is thoroughly washed with an organic solvent. This solution is subjected to potentiometric titration with an N / 2 potassium hydroxide ethyl alcohol solution using the electrode to determine the hydroxyl value.

The glass transition point of the toner is preferably 40 ° C to 70 ° C. When the glass transition point is less than 40 ° C, the heat-resistant storage stability may be insufficient, and when it exceeds 70 ° C, the low-temperature fixability may be adversely affected.
Here, the glass transition point (Tg) is specifically determined by the following procedure. Measurement is performed under the following measurement conditions using TA-60WS and DSC-60 manufactured by Shimadzu Corporation as measurement devices.
〔Measurement condition〕
・ Sample container: Aluminum sample pan (with lid)
-Sample amount: 5mg
Reference: Aluminum sample pan (alumina 10 mg)
・ Atmosphere: Nitrogen (flow rate 50ml / min)
・ Temperature conditions ・ Starting temperature: 20 ℃
・ Raising rate: 10 ° C / min
・ End temperature: 150 ℃
-Holding time: None-Temperature drop: 10 ° C / min
・ End temperature: 20 ℃
-Holding time: None-Temperature rising rate: 10 ° C / min
・ End temperature: 150 ℃
The measurement result is analyzed using the data analysis software (TA-60, version 1.52) manufactured by Shimadzu Corporation. The analysis method specifies a range of ± 5 ° C centering on the point showing the maximum peak on the lowest temperature side of the DrDSC curve which is the DSC differential curve of the second temperature rise, and the peak temperature is determined using the peak analysis function of the analysis software. Ask. Next, the maximum endothermic temperature of the DSC curve is determined using the peak analysis function of the analysis software in the range of the peak temperature + 5 ° C. and −5 ° C. in the DSC curve. The temperature shown here corresponds to the glass transition point (Tg) of the toner.

  The toner of the present invention obtained by the above-described toner production method of the present invention has a sharp particle size distribution, which is advantageous in that a high-quality image can be obtained.

(Developer)
The toner of the present invention obtained by the above-described toner production method of the present invention may be used as a one-component developer composed only of toner, or may be used as a two-component developer together with a carrier.
When used as the two-component developer, the toner is used by mixing with a magnetic carrier. The content ratio of the carrier and the toner in the developer is preferably 1 to 10 parts by mass of the toner with respect to 100 parts by mass of the carrier.

Examples of the magnetic carrier include iron powder, ferrite powder, magnetite powder having a particle size of about 20 μm to 200 μm, and a coated carrier obtained by coating the surface of the magnetic carrier with a resin. Among these, a coated carrier is particularly preferable.
Examples of the coating resin in the coated carrier include urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, epoxy resin, polyvinyl resin, polyvinylidene resin, acrylic resin, polymethyl methacrylate resin, polyacrylonitrile. Resin, polyvinyl acetate resin, polyvinyl alcohol resin, polyvinyl butyral resin, polystyrene resin, styrene-acrylic copolymer resin, polyvinyl chloride resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polycarbonate resin, polyethylene resin, polyvinyl fluoride Resin, polyvinylidene fluoride resin, polytrifluoroethylene resin, polyhexafluoropropylene resin, copolymer of vinylidene fluoride and acrylic monomer, Copolymers of vinylidene fluoride and vinyl fluoride, fluoro terpolymers such as of tetrafluoroethylene and vinylidene fluoride and non-fluoride monomers including, and a silicone resin.
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. The conductive powder preferably has an average particle size of 1 μm or less. When the average particle size is larger than 1 μm, it becomes difficult to control the electric resistance.

(Image forming method)
One embodiment of a method for carrying out an image forming method using the toner of the present invention obtained by the above-described toner manufacturing method of the present invention will be described with reference to FIG. The tandem image forming apparatus shown in FIG. 1 is a tandem type color image forming apparatus. The tandem image forming apparatus includes a copying apparatus main body 150, a paper feed table 200, a scanner 300, and an automatic document feeder (ADF) 400.

  The copying machine main body 150 is provided with an endless belt-shaped intermediate transfer member 1050 at the center. The intermediate transfer member 1050 is stretched around support rollers 1014, 1015, and 1016, and can rotate clockwise in FIG. An intermediate transfer body cleaning device 1017 for removing residual toner on the intermediate transfer body 1050 is disposed in the vicinity of the support roller 1015. The intermediate transfer member 1050 stretched by the support roller 1014 and the support roller 1015 has a tandem type in which four image forming units 1018 of yellow, cyan, magenta, and black face each other along the conveyance direction. A developing device 120 is disposed. An exposure device 1021 is disposed in the vicinity of the tandem developing device 120. A secondary transfer device 1022 is disposed on the side of the intermediate transfer body 1050 opposite to the side on which the tandem developing device 120 is disposed. In the secondary transfer device 1022, a secondary transfer belt 1024, which is an endless belt, is stretched around a pair of rollers 1023, and the transfer sheet conveyed on the secondary transfer belt 1024 and the intermediate transfer body 1050 are in contact with each other. Is possible. A fixing device 1025 is disposed in the vicinity of the secondary transfer device 1022. The fixing device 1025 includes a fixing belt 1026 that is an endless belt, and a pressure roller 1027 that is pressed against the fixing belt 1026.

  In the tandem image forming apparatus, a sheet reversing device 1028 for reversing the transfer paper for image formation on both sides of the transfer paper is disposed in the vicinity of the secondary transfer device 1022 and the fixing device 1025. .

  Next, formation of a full-color image (color copy) using the tandem developing device 120 will be described. That is, first, a document is set on the document table 130 of the automatic document feeder (ADF) 400, or the automatic document feeder 400 is opened and a document is set on the contact glass 1032 of the scanner 300. 400 is closed.

  When a start switch (not shown) is pressed, when a document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 1032 and then the document is set on the contact glass 1032. Immediately after that, the scanner 300 is driven, and the first traveling body 1033 and the second traveling body 1034 travel. At this time, the light from the light source is emitted from the first traveling body 1033 and the reflected light from the document surface is reflected by the mirror in the second traveling body 1034 and is received by the reading sensor 1036 through the imaging lens 1035 to be color. An original (color image) is read and used as black, yellow, magenta, and cyan image information.

  Each image information of black, yellow, magenta, and cyan is stored in each image forming unit 1018 (black image forming unit, yellow image forming unit, magenta image forming unit, cyan image) in the tandem developing unit 120. Each of the image forming units forms black, yellow, magenta, and cyan toner images. That is, each image forming means 1018 (black image forming means, yellow image forming means, magenta image forming means, and cyan image forming means) in the tandem developing means 120 is a static image as shown in FIG. An electrostatic latent image carrier 1110 (an electrostatic latent image carrier for black 1010K, an electrostatic latent image carrier for yellow 1010Y, an electrostatic latent image carrier for magenta 1010M, and an electrostatic latent image carrier for cyan 1010C); The electrostatic latent image carrier 1110 is uniformly charged, and the electrostatic latent image carrier is exposed for each color image-corresponding image based on each color image information (L in FIG. 2). An exposure apparatus for forming an electrostatic latent image corresponding to each color image on the electrostatic latent image carrier, and the electrostatic latent image for each color toner (black toner, yellow toner, magenta toner, and the like). A developing device 61 that forms a toner image using each color toner by developing with a cyan toner, a transfer charger 1062 for transferring the toner image onto the intermediate transfer body 1050, a cleaning device 63, and a static eliminator. 64, each monochrome image (black image, yellow image, magenta image, and cyan image) can be formed based on the image information of each color. The black image, the yellow image, the magenta image, and the cyan image formed in this way are respectively transferred to an electrostatic latent image carrier 1010K for black on an intermediate transfer member 1050 that is rotated by support rollers 1014, 1015, and 1016. The black image formed above, the yellow image formed on the yellow electrostatic latent image carrier 1010Y, the magenta image formed on the magenta electrostatic latent image carrier 1010M, and the electrostatic latent image carrier for cyan The cyan image formed on 1010C is sequentially transferred (primary transfer). Then, the black image, the yellow image, the magenta image, and the cyan image are superimposed on the intermediate transfer member 1050 to form a composite color image (color transfer image).

  On the other hand, in the paper feed table 200, one of the paper feed rollers 142 is selectively rotated to feed out a sheet (recording paper) from one of the paper feed cassettes 144 provided in multiple stages in the paper bank 143. The sheets are separated one by one and sent to the sheet feeding path 146, conveyed by the conveying roller 147, guided to the sheet feeding path 148 in the copying machine main body 150, and abutted against the registration roller 1049 to stop. Alternatively, the sheet feeding roller 142 is rotated to feed out the sheets (recording paper) on the manual feed tray 1054, separated one by one by the separation roller 1058, put into the manual feed path 1053, and abutted against the registration roller 1049 and stopped. . The registration roller 1049 is generally used while being grounded, but may be used in a state where a bias is applied to remove paper dust from the sheet. Then, the registration roller 1049 is rotated in synchronization with the synthesized color image (color transfer image) synthesized on the intermediate transfer member 1050, and a sheet (recording paper) is interposed between the intermediate transfer member 1050 and the secondary transfer device 1022. And transferring the composite color image (color transfer image) onto the sheet (recording paper) by the secondary transfer device 1022, thereby transferring the color image onto the sheet (recording paper). Is formed. The residual toner on the intermediate transfer member 1050 after the image transfer is cleaned by the intermediate transfer member cleaning device 1017.

  The sheet (recording paper) on which the color image has been transferred is conveyed by the secondary transfer device 1022 and sent to the fixing device 1025, where the combined color image (color) is generated by heat and pressure. (Transfer image) is fixed on the sheet (recording paper). Thereafter, the sheet (recording paper) is switched by the switching claw 1055 and discharged by the discharge roller 1056 and stacked on the paper discharge tray 1057 or switched by the switching claw 1055 and reversed by the sheet reversing device 1028 and transferred again. After being guided to the position and recording an image on the back side, it is discharged by the discharge roller 1056 and stacked on the discharge tray 1057.

  Examples of the present invention will be described below, but the present invention is not limited to these examples. Hereinafter, “parts” means “parts by mass” unless otherwise specified.

[Example 1]
(Manufacture of polyester)
690 parts of bisphenol A ethylene oxide 2-mole adduct and 335 parts of terephthalic acid are charged into a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, and condensed at 210 ° C. for 10 hours under a normal pressure nitrogen stream. Reacted. Next, the reaction was continued for 5 hours while dehydrating under reduced pressure of 10 to 15 mmHg, followed by cooling to obtain polyester (1). The obtained polyester resin had a weight average molecular weight of 6,000, an acid value of 10 KOHmg / g, and a glass transition point of 48 ° C.

(Prepolymer production)
Into a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, 795 parts of bisphenol A ethylene oxide 2-mole adduct, 200 parts of isophthalic acid, 65 parts of terephthalic acid, and 2 parts of dibutyltin oxide were added, and atmospheric pressure nitrogen was added. Under an air stream, the condensation reaction was performed at 210 ° C. for 8 hours. Next, the reaction was continued for 5 hours while dehydrating under reduced pressure of 10 to 15 mmHg, then cooled to 80 ° C., and reacted with 170 parts of isophorone diisocyanate in ethyl acetate for 2 hours to obtain a prepolymer (1). The obtained prepolymer had a weight average molecular weight of 5,000.

(Production of organic solvent composition)
In a tank, 170 parts of 35% carnauba wax ethyl acetate dispersion, 120 parts of polyester (1), 20 parts of PY155 (manufactured by Clariant), 70 parts of ethyl acetate and 2 parts of isophoronediamine are stirred and dissolved for 2 hours. Mixed. Subsequently, an organic solvent composition (1) was obtained by circulating and mixing for 1 hour using a high-efficiency disperser Ebara Milder (manufactured by Ebara Seisakusho). The acid value of the obtained organic solvent composition (1) was 4.5 KOH mg / g. In another tank, 25 parts of prepolymer (1) and 25 parts of ethyl acetate were added and dissolved and mixed with stirring for 4 hours to obtain an organic solvent composition (2).

(Manufacture of aqueous dispersion media)
In a tank, 945 parts of water, 40 parts of a 20% aqueous dispersion of styrene-methacrylic acid-butyl acrylate copolymer, 160 parts of 50% aqueous solution of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7: manufactured by Sanyo Chemical Industries), acetic acid 90 parts of ethyl was mixed and stirred to obtain an aqueous dispersion medium (1).

(Manufacture of toner 1)
Ebara Milder (manufactured by Taiheiyo Koki) and Ebara Milder at a speed of 350 g / min for the organic solvent composition (1), 40 g / min for the organic solvent composition (2) and 600 g / min for the aqueous dispersion medium (1). T. connected to the outlet. K. It supplied to the film mix (product made from Primex), and the emulsified dispersion (1) was obtained. T. at this time. K. The peripheral speed of the fill mix was set to 40 m / s. The obtained emulsified dispersion (1) was put into a container in which a stirrer and a thermometer were set, and the solvent was removed at 30 ° C. for 8 hours to obtain [Slurry 1].

(Washing-drying)
[Slurry 1]: 100 parts were filtered under reduced pressure, 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. 100 parts of 10% aqueous sodium hydroxide solution was added to the filter cake, mixed with a TK homomixer (30 minutes at 12,000 rpm), and then filtered under reduced pressure. To this filter cake, 100 parts of 10% hydrochloric acid was added, mixed with a TK homomixer, and filtered. To this filter cake, 300 parts of ion-exchanged water was added, mixed with a TK homomixer and then filtered twice to obtain [Filter cake 1].
[Filtration cake 1] was dried at 40 ° C. for 48 hours in a circulating drier and sieved with a mesh of 75 μm, and the resulting toner base particles: 100 parts of hydrophobic silica (hexamethyldisilazane surface treatment) Product, specific surface area: 200 m 2 / g): 0.5 part and hydrophobized rutile type titanium oxide (isobutyltrimethoxysilane surface-treated product, average primary particle size: 0.02 μm): 0.5 part by Henschel mixer The toner 1 was obtained by mixing.

[Example 2]
(Manufacture of toner 2)
The organic solvent composition (1) was 350 g / min, the organic solvent composition (2) was 40 g / min, and the aqueous dispersion medium (1) was connected to the static mixer and the static mixer outlet at a speed of 600 g / min. K. It supplied to the film mix (product made from PRIMIX), and the emulsification dispersion liquid (2) was obtained. T. at this time. K. The peripheral speed of the fill mix was set to 40 m / s. The obtained emulsified dispersion (2) was put into a container in which a stirrer and a thermometer were set, and the solvent was removed at 30 ° C. for 8 hours to obtain [Slurry 2]. After the washing step, toner 2 was obtained in the same manner as in Example 1.

[Example 3]
(Manufacture of toner 3)
Pipeline homomixer (Primix) and Pipeline Homo at a speed of 350 g / min for the organic solvent composition (1), 40 g / min for the organic solvent composition (2) and 600 g / min for the aqueous dispersion medium (1). T. connected to the mixer outlet. K. It supplied to the film mix (product made from Primex), and the emulsified dispersion (3) was obtained. T. at this time. K. The peripheral speed of the fill mix was set to 40 m / s. The obtained emulsified dispersion (3) was put into a container in which a stirrer and a thermometer were set, and the solvent was removed at 30 ° C. for 8 hours to obtain [Slurry 3]. After the washing step, toner 3 was obtained in the same manner as in Example 1.

[Example 4]
(Manufacture of toner 4)
Ebara Milder (manufactured by Taiheiyo Koki) and Ebara Milder at a speed of 525 g / min for the organic solvent composition (1), 60 g / min for the organic solvent composition (2) and 900 g / min for the aqueous dispersion medium (1). T. connected to the outlet. K. It supplied to the film mix (product made from Primex), and the emulsified dispersion (4) was obtained. T. at this time. K. The peripheral speed of the fill mix was set to 40 m / s. The obtained emulsified dispersion (4) was put into a container in which a stirrer and a thermometer were set, and the solvent was removed at 30 ° C. for 8 hours to obtain [Slurry 4]. After the washing step, toner 4 was obtained in the same manner as in Example 1.

[Comparative Example 1]
(Manufacture of toner 5)
Ebara Milder (manufactured by Taiheiyo Koki) and Ebara Milder at a speed of 350 g / min for the organic solvent composition (1), 40 g / min for the organic solvent composition (2) and 600 g / min for the aqueous dispersion medium (1). It was supplied to a pipeline homomixer (manufactured by Primex) using a conventional circulation line (the number of passes through the shearing means is multipassed) connected to the outlet, to obtain an emulsified dispersion (5). T. at this time. K. The peripheral speed of the fill mix was set to 40 m / s. The obtained emulsified dispersion (5) was put into a container equipped with a stirrer and a thermometer, and the solvent was removed at 30 ° C. for 8 hours to obtain [Slurry 5]. After the washing step, toner 5 was obtained in the same manner as in Example 1.

[Comparative Example 2]
(Manufacture of toner 6)
The conventional organic solvent composition (1) is connected to the static mixer and the static mixer outlet at a speed of 350 g / min, the organic solvent composition (2) is 40 g / min, and the aqueous dispersion medium (1) is 600 g / min. It was supplied to a pipeline homomixer (manufactured by Primex) using a circulation line (the number of passes through the shearing means), and an emulsified dispersion (6) was obtained. T. at this time. K. The peripheral speed of the fill mix was set to 40 m / s. The obtained emulsified dispersion (6) was put into a container equipped with a stirrer and a thermometer, and the solvent was removed at 30 ° C. for 8 hours to obtain [Slurry 6]. After the washing step, toner 6 was obtained in the same manner as in Example 1.

[Comparative Example 3]
(Manufacture of toner 7)
The organic solvent composition (1) was 350 g / min, the organic solvent composition (2) was 40 g / min, and the aqueous dispersion medium (1) was 600 g / min. K. It supplied to the film mix (product made from Primex), and the emulsified dispersion (7) was obtained. T. at this time. K. The peripheral speed of the fill mix was set to 40 m / s. The obtained emulsified dispersion (7) was put into a container equipped with a stirrer and a thermometer, and the solvent was removed at 30 ° C. for 8 hours to obtain [Slurry 7]. After the washing step, toner 7 was obtained in the same manner as in Example 1.

<Measurement of Dv, Dv / Dn>
For the obtained toners 1 to 7, volume average particle size (Dv), volume average particle size (Dv) / number average particle size (Dn) were measured as follows. The results are shown in Table 1.
The volume average particle diameter (Dv), the number average particle diameter (Dn), and the ratio (Dv / Dn) of each toner are determined using a particle size measuring device (“Multisizer III”, manufactured by Beckman Coulter, Inc.) and an aperture diameter of 100 μm. And analyzed with analysis software (Beckman Coulter Multisizer 3 Version 3.51). Specifically, 0.5 ml of 10% by weight surfactant (alkylbenzene sulfonate, Neogen SC-A, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) is added to a 100 ml beaker made of glass, and 0.5 g of each toner is added. The mixture was stirred with a microspatel, and then 80 ml of ion-exchanged water was added. The obtained dispersion was subjected to a dispersion treatment for 10 minutes with an ultrasonic disperser (W-113MK-II, manufactured by Honda Electronics Co., Ltd.). The dispersion was measured with the “Multisizer III” using Isoton III (manufactured by Beckman Coulter, Inc.) as the measurement solution. In the measurement, the toner sample dispersion was dropped so that the concentration indicated by the apparatus was 8 ± 2%. In this measurement method, it is important to adjust the concentration to 8 ± 2% from the viewpoint of the reproducibility of the particle size. Within this concentration range, no error occurs in the particle size.

<Image graininess, sharpness>
The obtained toners 1 to 7 were evaluated for image graininess and sharpness as follows.
Using a digital full-color copying machine (imageColor 2800 manufactured by Ricoh Co., Ltd.), the obtained toners 1 to 7 were used to output a photographic image in a single color, and the degree of granularity and sharpness was visually evaluated. In order from the best, “◎” is equivalent to offset printing, “○” is slightly worse than offset printing, “△” is much worse than offset printing, “×” is about the same as conventional electrophotographic images (very much Bad).

From the results of Table 1, in the method for producing toners of Examples 1 to 4, in which the mixed liquid of the oil phase and the aqueous medium is emulsified by passing the premixing unit and passing the shearing unit only once. Thus, it was shown that a toner having a low Dv / Dn value, that is, a highly uniform particle diameter, and a toner having excellent graininess and sharpness can be obtained.
On the other hand, for the mixed liquid of the oil phase and the aqueous medium, the method for producing the toners of Comparative Examples 1 to 3 is performed without using the circulation line and passing the shearing means a plurality of times or without passing the premixing means. Thus, it can be seen that, compared with the toner production methods of Examples 1 to 4, the obtained toner has low particle size uniformity and is not excellent in graininess and sharpness.

  The toner of the present invention obtained by the toner production method of the present invention has high particle size uniformity and excellent granularity and sharpness, so that a high-quality image can be obtained. Therefore, the toner is, for example, a toner used as a developer for developing an electrostatic charge image in electrophotography, electrostatic recording, electrostatic printing, and the like, and more specifically, a direct or indirect electrophotographic development system is used. It can be suitably used as a toner used in a copying machine, a laser printer, a plain paper fax machine, and the like.

FIG. 1 is a cross-sectional configuration diagram of a main part of an example of an image forming apparatus. FIG. 2 is a partially enlarged view of the image forming apparatus shown in FIG.

Explanation of symbols

1010K electrostatic latent image carrier for black 1010Y electrostatic latent image carrier for yellow 1010M electrostatic latent image carrier for magenta 1010C electrostatic latent image carrier for cyan 1014 support roller 1015 support roller 1016 support roller 1017 intermediate transfer cleaning device DESCRIPTION OF SYMBOLS 1018 Image formation means 1021 Exposure apparatus 1022 Secondary transfer apparatus 1023 Roller 1024 Secondary transfer belt 1025 Fixing apparatus 1026 Fixing belt 1027 Pressure roller 1028 Sheet reversing apparatus 1032 Contact glass 1033 First traveling body 1034 Second traveling body 1035 Imaging lens 1036 Reading sensor 1049 Registration roller 1050 Intermediate transfer member 1053 Manual feed path 1054 Manual feed tray 1055 Switching claw 1056 Ejection roller 1057 Ejection tray 1058 Separation Roller 61 Developing device 1062 Transfer charger 63 Cleaning device 64 Static eliminator 120 Tandem developing device 130 Document table 142 Paper feed roller 143 Paper bank 144 Paper feed cassette 145 Separating roller 146 Paper feed route 147 Transport roller 148 Paper feed route 150 Copying Main body 160 Charging device 200 Paper feed table 300 Scanner 400 Automatic document feeder (ADF)

Claims (20)

In an organic solvent, at least a binder resin, a colorant, and a release agent are dissolved or dispersed, and an oil phase composed of the obtained solution or dispersion and an aqueous medium are supplied to a shearing means, and the oil phase A method for producing a toner having an emulsification step of obtaining an emulsion by applying a shearing force to a mixture of the aqueous medium and the aqueous medium,
The mixture of the oil phase and the aqueous medium passes through the shearing means once, and before passing through the shearing means, the premixing means performs pre-mixing of the oil phase and the aqueous medium. A method for producing toner, comprising mixing.   The method for producing a toner according to claim 1, wherein the shearing means is a thin film rotating emulsifier.   The toner production method according to claim 1, wherein the premixing means is a rotor-stator type disperser.   The method for producing a toner according to claim 1, wherein the premixing means is a pipeline homomixer.   The toner production method according to claim 1, wherein the premixing means is a static mixer.   A binder resin precursor composed of a modified polyester resin is dissolved or dispersed in an organic solvent, and an oil phase composed of the resulting solution or dispersion, and the binder resin precursor is elongated or crosslinked in the organic solvent. An oil phase comprising the resulting solution or dispersion is emulsified and dispersed in an aqueous medium containing a dispersant to obtain an emulsified dispersion, and the binding is performed in the emulsified dispersion. 6. The method for producing a toner according to claim 1, wherein the resin precursor is subjected to an elongation reaction or a crosslinking reaction to remove the organic solvent.   The method for producing a toner according to claim 1, wherein the binder resin is a polyester resin.   The method for producing a toner according to claim 7, wherein the content of the polyester resin in the binder resin is 50 to 100% by mass.   The method for producing a toner according to any one of claims 7 to 8, wherein a polyester resin has a THF-soluble component having a weight average molecular weight of 1,000 to 30,000.   The toner production method according to claim 7, wherein the polyester resin has an acid value of 1.0 to 50.0 (KOH mg / g).   The method for producing a toner according to claim 7, wherein the glass transition point of the polyester resin is 35 to 65 ° C.   The method for producing a toner according to claim 6, wherein the binder resin precursor has a weight average molecular weight of 3,000 to 20,000.   The method for producing a toner according to claim 1, wherein the toner has an acid value of 0.5 to 40.0 (KOH mg / g).   The method for producing a toner according to claim 1, wherein the toner has a glass transition point of 40 to 70 ° C.   The method for producing a toner according to claim 1, wherein the oil phase contains a modified layered inorganic mineral obtained by modifying at least part of ions between layers of the layered inorganic mineral with organic ions.   The toner production method according to claim 1, wherein the obtained toner has a volume average particle diameter (Dv) of 3.0 to 7.0 μm.   The toner production method according to claim 1, wherein the obtained toner has a volume average particle diameter (Dv) / number average particle diameter (Dn) of 1.00 to 1.20.   18. The method for producing a toner according to claim 1, wherein in the obtained toner, particles having a particle size of 2.0 μm or less are 20% by number or less.   The method for producing a toner according to claim 1, wherein the obtained toner has an average circularity of 0.93 to 0.97.   A toner manufactured by the toner manufacturing method according to claim 1.