JP2010102142A - Toner and method for producing toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To produce a small particle size toner having a sharp particle size distribution, without requiring a classification step, and to provide a toner or a two-component developer having a longer lifetime and capable of preventing void generation and toner spattering at transfer. <P>SOLUTION: The toner includes colored particles, formed by making agglomeration in a mixture of a resin particle dispersion in which resin particles are dispersed, a pigment particle dispersion in which pigment particles are dispersed, and wax particle dispersion in which the wax particles are dispersed. The pigment particles include at least a quinacridone pigment and a naphthol pigment, at a compounding weight ratio of 1:1 to 1:9, and the volume particle size distributions of a quinacridone pigment particle dispersion and a naphthol pigment particle dispersion are regulated to be within a certain range. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a toner used in a copying machine, a laser printer, plain paper FAX, a color PPC, a color laser printer, a color FAX, and a complex machine thereof, and a toner manufacturing method.

  In recent years, image forming apparatuses such as printers are shifting from the purpose of office use to personal use, and there is a demand for a technology that realizes miniaturization, high speed, high image quality, and colorization. Therefore, a tandem color process that enables high-speed output of color images, and oilless fixing that achieves both high-gloss color images and non-offset properties without using fixing oil to prevent offset during fixing are required. Is done. These functions need to be compatible at the same time, and improving the characteristics of the toner as well as the process is an important factor.

  In a color printer, in a fixing process, it is necessary to melt and mix color toners in a color image to increase translucency. When toner fusing failure occurs, light scattering occurs on the surface or inside of the toner image, and the color tone of the toner is impaired. In addition, light does not enter the lower layer in the overlapping part of different color toners, and color reproducibility. Decreases. Therefore, the toner needs to have translucency. Further, it is required to realize oilless fixing without using silicone oil or the like for the fixing roller. In order to make this possible, a configuration in which a release agent such as wax is added to a binder resin having sharp melt characteristics has been put into practical use.

  However, the problem of the toner to which a release agent such as wax is added tends to increase the cohesiveness of the toner, so that the toner image is disturbed during transfer and transfer failure occurs, making it difficult to achieve both transfer and fixing. When used as two-component development consisting of toner and carrier particles, the low melting point component of the toner adheres to the carrier surface due to heat generated by collision or friction between the particles or mechanical collision or friction between the particles and the developer. A so-called spent phenomenon is likely to occur, and the spent phenomenon lowers the charging ability of the carrier and prevents the life of the developer from being extended.

The toner is generally composed of a resin component that is a binder resin, a pigment, a charge control agent, and, if necessary, an additive component such as a release agent. These materials are premixed at an appropriate ratio, heated and kneaded by heat melting, finely pulverized by an airflow type impact plate method or the like, and finely powder classified to complete toner base particles. There has also been proposed a method in which toner base particles are prepared by a chemical polymerization method.
The toner base particles are externally treated with an external additive such as hydrophobic silica to complete the toner. One-component development is composed only of toner, and the two-component developer is composed of toner and a carrier made of magnetic particles.

In the conventional kneading and pulverizing method, there is a limit to the particle size of the toner that can be actually produced economically and in performance. Therefore, a toner production method using various polymerization methods different from the kneading and pulverization method has been studied.
In Patent Document 1 below, a magenta toner for electrostatic charge development, which contains at least a quinacridone pigment and a naphthol pigment and is produced using a release agent dispersion, the colorant has the following conditions (a), (b (A) The average primary particle size D50 of the quinacridone pigment and the average primary particle size D50 of the naphtholic pigment are the average primary particle size D50 of the quinacridone pigment <the average of the naphtholic pigment (B) The average primary particle size D50 of the quinacridone pigment is the average primary particle size D50 of the quinacridone pigment, and the average primary particle of the naphthol pigment is A toner in which the diameter D50 is in the relationship of an average primary particle diameter D50 <200 nm of a naphthol pigment is disclosed, and quinac excellent in color development, developability, transferability, chargeability, fixability, etc. When using Don pigment and naphthol pigments, it is described to improve image storability and equivalent to other colors.
In the following Patent Document 2, a resin particle dispersion in which resin particles are dispersed and a colorant dispersion in which a colorant is dispersed in an aqueous medium are mixed to aggregate the resin particles and the colorant. In the method for producing a toner for developing an electrostatic charge image, comprising the steps of forming aggregated particles to prepare an aggregated particle dispersion, and heating and coalescing the aggregated particles to form toner particles. The average particle size of the colorant is 350 nm at most, the particle size of the cumulative volume of 84% of the colorant in the colorant dispersion is at most 500 nm, and the step of preparing the aggregated particle dispersion A method for producing a toner is further disclosed, which further includes a step of adding and mixing a fine particle dispersion in which fine particles are dispersed in the aggregated particle dispersion to adhere the fine particles to the aggregated particles to form adhered particles. , Conductive, developing property, transferring property, fixing property, properties of the cleaning and the like, in particular optically transparent, excellent in coloring property, provides a toner and the like that satisfy the image quality and high reliability have been described.
Main pigments used in the magenta toner include quinacridone pigments, naphthol pigments, and azo pigments. However, at present, none of them has reached a level that satisfies the coloring power, magenta hue, toner chargeability, transferability or particle formation characteristics.
When mixing and using quinacridone pigments and naphthol pigments to improve tinting strength and magenta hue, the shape of the core particles tends to be indefinite in the formation of aggregated particles in the aqueous system. Tends to be difficult to form.
In addition, the toner particle size distribution may be broad and it may be difficult to produce small particle size particles. In addition, the balance of aggregation of the resin particles, pigment particles and wax particles tends to be disturbed, and the pigment particles tend to remain in the aqueous system without being aggregated into the core particles.
JP 2006-65107 A JP-A-10-301333

The present invention provides a toner that can improve magenta tinting strength and magenta hue, can form stable core particles, and can produce a small particle size toner having a narrow particle size distribution without a classification step, and a toner manufacturing method. With the goal.
Also, in oilless fixing without using oil in the fixing roller, a release agent such as wax is used in the toner to achieve low temperature fixing property, high temperature non-offset property, paper separating property from the fixing roller, etc. and high temperature state. It is an object of the present invention to provide a toner and a method for producing the toner that achieve both storage stability during storage.
It is another object of the present invention to provide a toner and a method for producing the toner that can prevent a void or scatter during transfer and can achieve high transfer efficiency.

The present invention is produced by mixing and aggregating at least a resin particle dispersion in which resin particles are dispersed, a pigment particle dispersion in which pigment particles are dispersed, and a wax particle dispersion in which wax particles are dispersed in an aqueous medium. A toner containing colored particles, wherein the pigment particles include at least a quinacridone pigment and a naphthol pigment,
In the volume particle size distribution of the quinacridone pigment particle dispersion in which the weight blending ratio of the quinacridone pigment and the naphthol pigment is 1: 1 to 1: 9 and the quinacridone pigment particles are dispersed, In the cumulative volume particle size distribution from the diameter side, if PQ16 is the cumulative particle size of 16%, PQ50 is the particle size of 50% cumulative and PQ84 is the particle size of 84% cumulative, PQ16 is 20 ~ 150 nm, PQ50 is 40 to 250 nm, PQ84 is 350 nm or less, PQ84 / PQ16 is 1.2 to 2.5,
In the volume particle size distribution of the naphthol pigment particle dispersion in which the naphthol pigment particles are dispersed, the cumulative particle size distribution from the small particle size side is PN16. Assuming that the particle size of 50% is PN50 and the particle size of 84% is PN84, PN16 is 20 to 150 nm, PN50 is 40 to 250 nm, PN84 is 350 nm or less, and PN84 / PN16 is 1.2 to 2.5. It is a certain toner.
The present invention also includes mixing and mixing at least a resin particle dispersion in which resin particles are dispersed, a pigment particle dispersion in which pigment particles are dispersed, and a wax particle dispersion in which wax particles are dispersed in an aqueous medium. A method for producing a toner, comprising: a step of generating a liquid; and a step of adding a flocculant to the mixed solution to aggregate the resin particles, the pigment particles, and the wax particles to generate colored particles,
The pigment particles include at least a quinacridone pigment and a naphthol pigment,
The weight blending ratio of the quinacridone pigment and the naphthol pigment is 1: 1 to 1: 9,
In the volume particle size distribution of the quinacridone pigment particle dispersion in which the quinacridone pigment particles are dispersed, in the volume particle size cumulative distribution when accumulated from the small particle size side, the particle size that becomes 16% cumulative is PQ16. Assuming that the particle size of 50% is PQ50 and the particle size of 84% cumulative is PQ84, PQ16 is 20 to 150 nm, PQ50 is 40 to 250 nm, PQ84 is 350 nm or less, and PQ84 / PQ16 is 1.2 to 2.5. Yes,
In the volume particle size distribution of the naphthol pigment particle dispersion in which the naphthol pigment particles are dispersed, the cumulative particle size distribution from the small particle size side is PN16. Assuming that the particle size of 50% is PN50 and the particle size of 84% is PN84, PN16 is 20 to 150 nm, PN50 is 40 to 250 nm, PN84 is 350 nm or less, and PN84 / PN16 is 1.2 to 2.5. This is a method for producing a toner.

By the above means, at the time of agglomeration reaction in an aqueous medium, plural types of pigments can be uniformly dispersed in the core particles, improving magenta tinting strength and magenta hue, and forming a small particle size toner having a narrow particle size distribution. Is possible.
Moreover, it is possible to achieve both low-temperature fixability, high-temperature non-offset property, and storage stability.

  In addition, in the tandem color process where image forming stations with multiple photoconductors and development units are arranged side by side and the toner of each color is successively transferred to the transfer body, it is possible to prevent voids and reverse transfer during transfer. In addition, high transfer efficiency can be obtained.

(1) Polymerization and aggregation The resin particle dispersion is obtained by homopolymerizing or copolymerizing a vinyl monomer (vinyl resin) by subjecting the vinyl monomer to emulsion polymerization or seed polymerization in a surfactant. ) Resin particles are dispersed in a surfactant to produce a dispersion. Examples of the means include known dispersion devices such as a high-speed rotation type emulsifying device, a high-pressure emulsifying device, a colloid type emulsifying device, a ball mill having a media, a sand mill, or a dyno mill.

  When the resin particles are a resin other than the homopolymer or copolymer of the vinyl monomer, the resin is dissolved in an oily solvent as long as the resin is dissolved in an oily solvent having a relatively low solubility in water. Dissolve in solvent, disperse fine particles in water together with surfactant and polymer electrolyte using a disperser such as a homogenizer, and then heat or reduce pressure to evaporate the oily solvent. A dispersion is prepared by dispersing the resin particles in a surfactant.

  The pigment particle dispersion is prepared by adding pigment particles in an aqueous system and dispersing them using the appropriate dispersing means described above.

The wax particle dispersion is prepared by adding wax particles in an aqueous system and dispersing them using the appropriate dispersing means described above.
The toner or toner manufacturing method according to the present invention includes at least a resin particle dispersion in which resin particles are dispersed, a pigment particle dispersion in which pigment particles are dispersed, and a wax particle dispersion in which wax particles are dispersed in an aqueous medium. This is a toner containing colored particles in which a liquid mixture is produced by adding a flocculant to the liquid mixture, and resin particles, pigment particles and wax particles are aggregated to produce colored particles.
The pigment particles include at least a quinacridone pigment and a naphthol pigment, the weight blending ratio of the quinacridone pigment and the naphthol pigment is 1: 1 to 1: 9, and the quinacridone in which the quinacridone pigment particles are dispersed. In the volume particle size distribution of the system pigment particle dispersion liquid, the cumulative particle size distribution from the small particle size side is PQ16, the particle size of cumulative 50% is PQ16, and the cumulative particle size of PQ50 is 84. %, When PQ84 is 20 to 150 nm, PQ50 is 40 to 250 nm, PQ84 is 350 nm or less, and PQ84 / PQ16 is 1.2 to 2.5,
In the volume particle size distribution of the naphthol pigment particle dispersion in which the naphthol pigment particles are dispersed, the cumulative particle size distribution from the small particle size side is PN16. Assuming that the particle size of 50% is PN50 and the particle size of 84% is PN84, PN16 is 20 to 150 nm, PN50 is 40 to 250 nm, PN84 is 350 nm or less, and PN84 / PN16 is 1.2 to 2.5. is there.
The weight blending ratio of the quinacridone pigment and the naphthol pigment is preferably 1: 1 to 1: 8, more preferably 1: 2 to 1: 5, and still more preferably 1: 2 to 1: 4. This is a preferable range for securing the magenta hue and the magenta color density. Further, the inclusion of a large amount of naphthol pigment is advantageous for producing uniform core aggregated particles.
Preferably, PQ16 is 20 to 80 nm, PQ50 is 40 to 180 nm, PQ84 is 250 nm or less, PQ84 / PQ16 is 1.2 to 2.0,
More preferably, PQ16 is 20 to 60 nm, PQ50 is 40 to 120 nm, PQ84 is 220 nm or less, and PQ84 / PQ16 is 1.2 to 2.0.
Preferably, PN16 is 20 to 80 nm, PN50 is 40 to 180 nm, PN84 is 250 nm or less, PN84 / PN16 is 1.2 to 1.8,
More preferably, PN16 is 20 to 60 nm, PN50 is 40 to 120 nm, PN84 is 220 nm or less, and PN84 / PN16 is 1.2 to 1.8.
When the core particles are formed by mixing and aggregating the resin particle dispersion, the pigment particle dispersion, and the wax particle dispersion, the aggregation between the resin particles and the wax particles can be performed uniformly. Particles remaining in water without being taken into core particles can be reduced.
When PQ16 is larger than 150 nm, PQ50 is larger than 250 nm, PQ84 is larger than 350 nm, and PQ84 / PQ16 is larger than 2.5, the pigment particles are difficult to be incorporated into the core particles, and the pigment particles remaining in the aqueous system increase. It tends to be easy to do. In addition, the pigment particles in the core particles are likely to be unevenly distributed, and uniform dispersion is difficult to obtain.
It is also preferred that particles of 200 nm or less are present in an amount of 70% by volume or more, and particles exceeding 450 nm are 10% by volume or less.
Further, when PQ16 is smaller than 20 nm, PQ50 is smaller than 40 nm, and PQ84 / PQ16 is smaller than 1.2, the load at the time of generating the pigment dispersion increases, heat generation increases, and productivity tends to decrease. It becomes. Pigment dispersion liquid It is difficult to maintain the dispersion state of the pigment particles, and reaggregation of the pigment particles tends to occur.
When PN16 is greater than 150 nm, PN50 is greater than 250 nm, PN84 is greater than 350 nm, and PN84 / PN16 is greater than 2.5, the pigment particles are less likely to be incorporated into the core particles and the pigment particles remaining in the aqueous system increase. It tends to be easy to do. In addition, the pigment particles in the core particles are likely to be unevenly distributed, and uniform dispersion is difficult to obtain.
It is also preferable that particles of 200 nm or less are present in an amount of 65% by volume or more, and particles exceeding 500 nm are 10% by volume or less.
In addition, when PN16 is smaller than 20 nm, PN50 is smaller than 40 nm, and PN84 / PN16 is smaller than 1.2, the load at the time of pigment dispersion generation increases, heat generation increases, and productivity tends to decrease. It becomes. Pigment dispersion liquid It is difficult to maintain the dispersion state of the pigment particles, and reaggregation of the pigment particles tends to occur.
By adding a pigment concentration of about 10 to 30 wt% in an aqueous medium to which a surfactant is added, and emulsifying and dispersing the pigment by a high shearing force generated by a rotating body that rotates at high speed through a fixed gap. The pigment particles can be finely emulsified and dispersed.
For example, a gap of about 0.1 mm to 10 mm is provided on the tank wall in the tank of a certain capacity shown in FIGS. 3 and 4, and the rotating body is 30 m / s or more, preferably 40 m / s or more, more preferably 50 m / s. By rotating at a high speed of s or more, a strong shearing force acts on the aqueous system, and an emulsified dispersion of fine pigment particles is obtained. The treatment liquid can be formed by a treatment for about 30 seconds to 5 minutes.
A rotating body that rotates at a speed of 30 m / s or more, preferably 40 m / s or more, more preferably 50 m / s or more, with a gap of about 1 to 100 μm provided to a fixed stationary body as shown in FIGS. By adding a strong shearing force action, a fine pigment particle dispersion can be prepared.
Compared with a disperser such as a homogenizer, particles having a small particle size and a narrow particle size distribution can be formed. Further, even if the particles are left for a long time, the fine particles forming the dispersion liquid do not re-aggregate and can maintain a stable dispersion state, and the storage stability of the particle size distribution is improved.
The particle size can be measured using a Horiba laser diffraction particle size measuring device (LA920), a Shimadzu laser diffraction particle size measuring device (SALD2100), or the like. In LA920, the measurable range is 0.022 to 2000 μm, and the average particle size and distribution are calculated as a frequency (%) for each particle size range divided in a certain range based on the measured particle size distribution.
In the toner or toner production method of the present invention, it is also preferable that the quinacridone pigment particle dispersion and the naphthol pigment particle dispersion satisfy the relationship of (Equation 1).

By making the dispersion particle size of the naphthol pigment particles smaller than the dispersion particle size of the quinacridone pigment particles, the coloring power of the naphthol pigment can be extracted and the magenta hue can be improved. it can. In addition, in the formation of the core aggregated particles, it is possible to suppress a decrease in surface smoothness that seems to be caused by the naphthol pigment. Preferably, PN50 is PQ50 × 0.5 to PQ50 × 0.8, and more preferably, PN50 is PQ50 × 0.6 to PQ50 × 0.8.
In the toner or toner manufacturing method of the present invention, in the quinacridone pigment particle dispersion in which the quinacridone pigment particles are dispersed, the nonionic surfactant and the anionic surfactant are mixed in a polymerization blend ratio of 1: 1 to 5: 1 is preferable.
In addition, in the naphthol pigment particle dispersion in which naphthol pigment particles are dispersed, it is preferable to include a nonionic surfactant and an anionic surfactant in a polymerization blend ratio of 1: 1 to 5: 1.
Resin particles, wax particles, quinacridone pigment particles, and naphthol pigment particles are uniformly agglomerated to produce an effect in producing small core particles. It is preferable that it is contained at a polymerization blending ratio of 1.5: 1 to 4: 1, more preferably at a polymerization blending ratio of 2: 1 to 3: 1.
Moreover, it is also preferable that the weight compounding amount of the nonionic surfactant in the naphthol pigment particle dispersion is 1.1 to 5 times that of the nonionic surfactant in the quinacridone pigment particle dispersion. In the formation of the core aggregated particles, the aim is to suppress the surface from appearing to be uneven due to the naphthol-based pigment, and to reduce the smoothness. Preferably it is 1.2 to 4 times, more preferably 1.5 to 3 times.
In the toner or toner production method of the present invention, the nonionic surfactant HLB (Hydrophile-Lipophile Balance) used in the quinacridone pigment particle dispersion or naphthol pigment particle dispersion is 13.3 to 18.6. Preferably there is. Since the nonionic surfactant HLB is smaller than 18.6 and larger than 13.3, the resin particles, wax particles, quinacridone pigment particles and naphthol pigment particles are uniformly agglomerated to form a small particle size core. Effective for particle generation. The range is preferably 15.2 to 17.6, and more preferably 16 to 17.6.
Here, the HLB value is a value representing the degree of affinity of the surfactant to water and oil (an organic compound insoluble in water).
Particularly, the HLB value (Hydrophile-Lipophile Balance) of the nonionic surfactant is HLB = (MH × 20) / (MH + ML) where ML is the molecular weight of the lipophilic part of the surfactant and MH is the molecular weight of the hydrophilic part. (Griffin method).
Nonionic surfactants (nonionic dispersants) include higher alcohol ethylene oxide adducts, alkylphenol ethylene oxide adducts, fatty acid ethylene oxide adducts, polyhydric alcohol fatty acid ester ethylene oxide adducts, fatty acid amide ethylene oxide adducts, Polyalkyl alcohol alkyl ethers, fat and oil ethylene oxide adducts, polyethylene glycol type nonionic surfactants such as polypropylene glycol ethylene oxide adducts, glycerol fatty acid esters, pentaerythritol fatty acid esters, sorbitol and sorbitan fatty acid esters, Polyhydric alcohol type nonionic surfactants such as fatty acid esters of sucrose, alkyl ethers of other alcohols, fatty acid amides of alkanolamines, etc. Can be preferably used.
In the toner or toner manufacturing method of the present invention, the anionic surfactant used in the quinacridone pigment particle dispersion or naphthol pigment particle dispersion may be sulfuric acid such as higher alcohol sulfate ester salt or higher alkyl ether sulfate ester salt. Phosphate salts such as ester salts, alkylbenzene sulfonates, alkyl naphthalene sulfonates or higher alkyl sulfonates, higher alcohol phosphate salts (for example, salts with sodium, potassium, lithium, or calcium) And other
Polyoxyethylene alkyl ether sulfate ammonium salt, polyoxyethylene alkyl ether sulfate sodium salt, polyoxyethylene alkyl phenyl ether ammonium sulfate salt, polyoxyethylene alkylphenyl ether sulfate sodium salt, alkyl ether carboxylate or dialkyl sulfosuccinate (e.g., sulfosuccinate) Acid 2-ethylhexyl ester sodium salt).
Among them, lauryl alcohol sulfate sodium salt, which is a higher alcohol sulfate, sodium lauryl ether sulfate, which is a higher alkyl ether sulfate, sodium alkylbenzene sulfonate having 12 to 16 carbon atoms, which is an alkylbenzene sulfonate ( For example, sodium dodecylbenzenesulfonate) or alkyl naphthalenesulfonate is a particularly preferable material.
(2) In oilless fixing that does not use oil in the wax fixing roller, low temperature fixing property, high temperature non-offset property, improvement of separation from a heating roller such as copy paper during fixing, and storage stability at high temperature are ensured. Therefore, it is preferable to add a wax, and it is also preferable to add a plurality of waxes.
In the toner or toner manufacturing method according to the present invention, it is also preferable to add a certain amount of polypropylene glycol ethylene oxide adduct to the wax particle dispersion.
The amount of the polypropylene glycol ethylene oxide adduct is preferably 3 to 20 parts by weight with respect to 100 parts by weight of the wax particles. The pot life (dispersion stability) of the wax dispersion is maintained, and the resin particles, wax particles, quinacridone pigment particles, and naphthol pigment particles are uniformly agglomerated to produce a core particle having a small particle size. In particular, the aggregation speed of the wax particles can be optimized, and uniform dispersibility in the core particles of the pigment particles can be obtained together with the wax particles. As a result, the color density per unit area is increased, leading to a reduction in toner consumption.
Preferably, the amount of the polypropylene glycol ethylene oxide adduct is 3 to 15 parts by weight, more preferably 3 to 10 parts by weight, based on 100 parts by weight of the wax particles.
As the polypropylene glycol ethylene oxide adduct, a nonionic surfactant obtained by adding ethylene oxide to propylene glycol, which is called a pluronic type nonionic surfactant, is preferable.
The ethylene oxide in the total molecule of the polypropylene glycol ethylene oxide adduct is preferably 40 wt% or more and 80 wt% or less. Preferably they are 50 wt% or more and 80 wt% or less, More preferably, 70 wt% or more and 80 wt% or less are preferable.
This is an appropriate range for forming uniformly agglomerated core particles by combining the aggregation speeds of resin particles, wax particles, quinacridone pigment particles and naphthol pigment particles. This is a range where the balance between hydrophobicity and hydrophilicity can be taken.
The weight average molecular weight of the propylene glycol moiety which is a hydrophobic group is preferably 1750 or more and 3850 or less. Preferably 2250 or more and 3850 or less are preferable. More preferably 2750 or more and 3850 or less.
Propylene glycol has low water solubility and is soluble in water up to several hundred molecular weights, but not higher molecular weights. This is because by setting it to 1750 or more, the adsorption site to the wax particles is secured, and the wax particles have appropriate hydrophobicity. By setting it to 3850 or less, an effect of preventing agglomeration of wax particles from proceeding excessively can be obtained.
Its chemical structural formula is shown in (Chemical Formula 1). This nonionic surfactant has a shape in which a hydrophilic group is located at both ends with a hydrophobic group in between. a, b, and c are integers, and are set as needed to adjust the weight average molecular weight of the propylene glycol moiety and the weight ratio of ethylene oxide in the total molecule of the polypropylene glycol ethylene oxide adduct.

In the toner or toner manufacturing method according to the present invention, it is also preferable that the wax particle dispersion contains a polymer dispersant.
During the agglomeration reaction in the aqueous system, the phenomenon in which the quinacridone pigment particles and the naphthol pigment particles are unevenly distributed and aggregated in the core particles can be suppressed, and the dispersibility of the pigment particles in the core particles can be improved. In addition, generation of particles having a light color density is suppressed, and formation of particles having a magenta color is possible. As a result, the magenta color density per unit area is increased, leading to a reduction in toner consumption.
The polymer dispersant is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the wax particles. More preferably, it is 0.5-8 weight part, More preferably, it is 1-5 weight part.
As the polymer dispersant, polyvinyl alcohol or alcohol of partially saponified polyvinyl alcohol is preferable.
Copolymer resins having a hydrophilic part and a hydrophobic part in the molecule, for example, styrene-acrylic acid copolymer, styrene-acrylic acid-acrylic acid alkyl ester copolymer, styrene-methacrylic acid copolymer Or acrylic acid-based dispersants such as styrene-methacrylic acid-acrylic acid alkyl ester copolymers,
For example, a maleic acid dispersant such as a styrene-maleic acid copolymer, a styrene-maleic acid half ester copolymer, an acrylic ester-maleic acid copolymer, or a styrene-acrylic acid ester-maleic acid copolymer,
For example, sulfonic acid-based dispersants such as acrylic acid ester-styrene sulfonic acid copolymer, styrene-methacryl sulfonic acid copolymer, or acrylic acid ester-allyl sulfonic acid copolymer, or salts thereof can be mentioned. .
Alternatively, acrylic monomers containing hydroxyl groups include β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, methacryl Acid γ-hydroxypropyl, 3-chloro-2-hydroxypropyl acrylate, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate Water-soluble polymers such as esters, N-methylol acrylamide and N-methylol methacrylamide are preferred.
Alternatively, a water-soluble urethane resin (such as a reaction product of polyethylene glycol, polycaprolactone diol and the like and polyisocyanate) is preferable.
Alternatively, water-soluble polymers such as vinyl methyl ether, vinyl ethyl ether, and vinyl propyl ether are preferable.
Or esters of compounds containing vinyl alcohol and a carboxyl group, such as vinyl acetate, vinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acrylic acid chloride, methacrylic acid chloride and other acids Water-soluble polymers such as chlorides are preferred.
Alternatively, water-soluble polymers such as homopolymers or copolymers such as those having a nitrogen atom such as vinylpyridine, vinylpyrrolidone, vinylimidazole, ethyleneimine or a heterocyclic ring thereof are preferable.
Alternatively, polyoxyethylene, polyoxypropylene, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl phenyl ether, polyoxy Polyoxyethylene-based water-soluble polymers such as ethylene stearyl phenyl ester and polyoxyethylene nonyl phenyl ester are preferred.
Alternatively, water-soluble polymers such as alkyl cellulose, hydroxy-alkyl cellulose, carboxyalkyl cellulose, and celluloses such as methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose are preferable. These celluloses can be dissolved in water at 25 ° C. at 0.5% or more, and those having an etherification degree of 0.6 to 1.5 and an average degree of polymerization of 50 to 3000 are preferable.
Among these, acrylic acid such as styrene-acrylic acid copolymer, styrene-acrylic acid-acrylic acid alkyl ester copolymer, styrene-methacrylic acid copolymer, or styrene-methacrylic acid-alkyl acrylate copolymer. Dispersants,
Maleic acid-based dispersants such as styrene-maleic acid copolymer, styrene-maleic acid half ester copolymer, acrylic acid ester-maleic acid copolymer or styrene-acrylic acid ester-maleic acid copolymer,
A sulfonic acid dispersant such as an acrylate-styrene sulfonic acid copolymer, a styrene-methacryl sulfonic acid copolymer, or an acrylate-allyl sulfonic acid copolymer, or a salt thereof is preferable.
Polyolefin maleate sodium (Na) salts using polyolefins such as polyethylene and polypropylene can be preferably used as those having the effect of enhancing the adsorptivity to wax. Further, a polyolefin maleate sodium (Na) salt having 10 to 30 carbon atoms can be preferably used.
It is preferable to dissolve the polymer dispersant by forming a salt at the maleic acid or acrylic acid moiety in the polymer dispersant. Examples of the alkali neutralizer include aminomethylpropanol, 2-aminoisopropanol, triethanolamine, and aqueous ammonia.
Or inorganic alkali agents, such as alkali metal hydroxides, such as sodium hydroxide, lithium hydroxide, or potassium hydroxide, etc. can be mentioned.
The content of the alkali neutralizer can be an amount (neutralization equivalent) or more that can neutralize the polymer dispersant as a counter ion, and is approximately 1.2 to 1.5 of the neutralization equivalent. It is preferable from the point of cohesion etc. to contain in double quantity.
From the viewpoint of the dispersion state of the dispersion, the agglomeration property with respect to the agglomeration reaction temperature of the core particles, the developability, and the fixability, the polymer-based dispersant has a glass transition point of 40 to 150 ° C., a softening point of 90 to 220 ° C., and a weight average molecular weight of 3000-50,000 and an acid value of 50-350 mgKOH / g are preferable.
More preferably, the glass transition point is 50 to 130 ° C., the softening point is 100 to 200 ° C., the weight average molecular weight is 5000 to 30,000, the acid value is 80 to 250, and more preferably, the glass transition point is 90 to 130 ° C. The softening point is preferably 130 to 190 ° C, the weight average molecular weight is 7,000 to 40,000, and the acid value is preferably 100 to 200.
By setting the glass transition point to 40 ° C. or more and 150 ° C. or less, the agglomeration reaction in the aqueous medium is excessively accelerated so that the generated core particles are coarsened, and the wax particles are It tends to be able to suppress remaining in the aqueous system without being taken into the core particles.
By setting the softening point to 90 ° C. or higher and 220 ° C. or lower, the generated core particles tend to be coarse and the residual phenomenon in the aqueous system can be suppressed without the wax particles being taken into the core particles.
By setting the weight average molecular weight to 3000 or more and 50,000 or less, it is possible to suppress the coarsening of the core particles and the phenomenon that the wax particles remain in the aqueous system without being taken into the core particles.
By setting the acid value to 50 or more and 350 or less, the dispersion stability of the wax dispersion liquid is maintained, the progress of aggregation is stabilized, and the coarsening of the produced core particles tends to be suppressed.
In particular, the glass transition point of the polymer dispersant is preferably equal to or higher than the temperature at which the core particles are aggregated. The glass transition point is preferably 90 ° C. or higher. The reason for this is that in the process of increasing the temperature in the aqueous system, the wax particles are likely to aggregate from the temperature range exceeding the glass transition point of the polymer dispersant, which also incorporates the pigment particles into the aqueous system. It tends to be a large floating residue. When the glass transition point of the polymer dispersant is equal to or higher than the aggregation temperature of the core particles, a large residue floating in the aqueous system tends not to be generated.
The acid value refers to the number of milligrams of potassium hydroxide required to neutralize the acid contained in 1 g of a sample. The sample is dissolved in alcohol-ether and titrated with 0.5N potassium hydroxide using phenolphthalein as an indicator. Performed in accordance with JIS-K-0070.
It is also preferable to use a polymer dispersant together with the polypropylene glycol ethylene oxide adduct, and the weight blending ratio is preferably 50: 1 to 1:20. More preferably, it is 20: 1 to 1: 1, and further preferably 2: 1 to 1: 1. The aggregation rate of resin particles, wax particles, quinacridone pigment particles and naphthol pigment particles can be adjusted, and the state in which the wax particles and pigment particles are agglomerated and aggregated in the core particles can be suppressed, and the pigment can be suppressed. The ratio is such that the effect of uniformly dispersing the particles and wax particles can be exhibited.
In the toner or toner manufacturing method of the present invention, the wax preferably contains at least an ester wax having an endothermic peak temperature of 30 to 90 ° C. By blending ester wax, the core particle surface, which seems to be affected by naphthol pigment particles, in the aggregation with resin particles, quinacridone pigment particles and naphthol pigment particles can reduce unevenness and give smoothness. The pigment particles and wax particles can be uniformly dispersed in the core aggregated particles, and the effect of increasing the magenta color density can be obtained.
Preferably it is 40-85 degreeC, More preferably, it is 45-80 degreeC, More preferably, it is 50-74 degreeC. When the temperature is 30 ° C. or higher, storage stability is improved, and when the temperature is 90 ° C. or lower, low-temperature fixability and color gloss are improved, and the surface smoothness of the core aggregated particles is improved.
A preferable ester wax is an ester wax composed of at least one of a higher alcohol having 16 to 24 carbon atoms and a higher fatty acid having 16 to 24 carbon atoms.
Moreover, as a preferable ester wax, an ester wax having an iodine value of 25 or less and a saponification value of 30 to 300 is preferable.
In the toner or toner production method of the present invention, as a preferred embodiment of the wax, a configuration in which a plurality of waxes are added is also preferred.
As the preferred first wax form, the wax contains at least a first wax and a second wax, and the endothermic peak temperature (referred to as melting point Tmw1 (° C.)) of the first wax by DSC method is 30 to 90 ° C. The endothermic peak temperature (melting point Tmw2 (° C.)) of the second wax by DSC method is preferably 80 to 120 ° C.
Tmw1 is preferably 40 to 85 ° C, more preferably 45 to 80 ° C, and still more preferably 50 to 74 ° C. Tmw2 is more preferably 85 to 100 ° C, further preferably 90 to 100 ° C.
By using waxes having different melting points, the functions of the wax are separated, so that both low temperature fixing and high temperature non-offset properties can be achieved, and a wide fixing temperature region characteristic can be obtained.
When Tmw1 is smaller than 30 ° C., the generated core particles tend to be coarse and the storage stability tends to deteriorate. When it is higher than 90 ° C., the low-temperature fixability and the color gloss tend not to be improved.
When Tmw2 is smaller than 80 ° C., the high temperature non-offset property and the paper separation property tend to be weakened. When the temperature exceeds 120 ° C., the cohesiveness of the wax decreases, and the wax particles and pigment particles that float and remain without being taken into the core particles in the aqueous system increase, and the shape tends to be nonuniform.
As a preferred second form, the wax contains at least a first wax and a second wax, and the first wax is at least a higher alcohol having 16 to 24 carbon atoms and a higher fatty acid having 16 to 24 carbon atoms. It is preferable that the ester wax comprises one and the second wax contains an aliphatic hydrocarbon wax.
As a preferred third form, the wax contains at least a first wax and a second wax, the first wax contains a wax having an iodine value of 25 or less and a saponification value of 30 to 300, and the second wax. The wax preferably contains an aliphatic hydrocarbon wax.
By using the wax containing the first wax containing the specific wax together with the second wax containing the specific aliphatic hydrocarbon wax as the wax, the fat that remains floating without being taken into the core particles. The generation of the group hydrocarbon wax particles can be suppressed, the particle size distribution of the core particles can be prevented from becoming broad, and the phenomenon that the core particles can be rapidly coarsened when shelled can be suppressed.
During the heat aggregation, the first wax is compatibilized with the resin, which promotes the aggregation of the aliphatic hydrocarbon wax with the resin, is uniformly incorporated, is not incorporated into the core particles, is suspended, and remains. It seems that the generation of wax particles can be prevented. Furthermore, the first wax tends to be improved in low-temperature fixability due to partial progress of compatibilization with the resin. In addition, since the aliphatic hydrocarbon wax hardly compatibilizes with the resin, this wax can exhibit the function of improving the high temperature offset property and the separation property of the copy paper from the fixing roller. That is, the first wax has a function as a dispersion aid during the emulsification dispersion treatment of the aliphatic hydrocarbon wax, and further has a function as a low-temperature fixing aid.
In the first, second or third preferred form of the wax, when the core particles are formed by aggregating the wax particles having different melting points with the resin particles and pigment particles in the aqueous system, the first wax, the second wax When the dispersions emulsified and dispersed separately for each wax are mixed with the resin dispersion and the pigment dispersion and heated to agglomerate, the wax particles float without being incorporated into the core particles due to the difference in the melting rate of the wax. And the particle size distribution tends to be widened without agglomeration of the core particles.
Therefore, in the production of the wax particle dispersion, it is preferable that the first wax and the second wax are mixed and emulsified and dispersed. In this method, the first wax and the second wax are heated and emulsified and dispersed in the emulsifying and dispersing apparatus at a constant blending ratio. The charging may be performed separately or simultaneously, but it is preferable that the final dispersion liquid contains the first wax and the second wax in a mixed state.
Further, in the first, second or third embodiment preferable as the wax, when the weight ratio of the first wax with respect to 100 parts by weight of the wax in the wax particle dispersion is ES1, and the weight ratio of the second wax is FT2, FT2 / ES1 is preferably 0.2 to 10. More preferably, it is 1-9, More preferably, it is the range of 1.5-3. If it is less than 0.2, that is, if the weight ratio of the first wax is too large, the effect of high temperature non-offset property cannot be obtained, and the storage stability tends to deteriorate. If it is larger than 10, that is, if the weight ratio of the second wax is too large, low-temperature fixing cannot be realized, and the above-mentioned core particles tend to be coarse. Further, setting the blending ratio of FT2 to 1.5 times or more and 3 times or less of ES1 is a well-balanced ratio capable of satisfying both low temperature fixing property, high temperature storage stability and fixing high temperature non-offset property.
In the first, second, or third embodiment preferable as the wax, the total amount of added wax is preferably 5 to 30 parts by weight with respect to 100 parts by weight of the binder resin. Preferably it is 8-25 weight part, More preferably, 10-20 weight part is preferable. When the amount is less than 5 parts by weight, the low temperature fixing property, the high temperature non-offset property, and the separation property of the copying paper from the fixing roller tend to deteriorate. When the amount is more than 30 parts by weight, it tends to be difficult to control particles having a small particle diameter.
In the 1st, 2nd or 3rd form preferable as a wax, Tmw2 is 5 degreeC or more higher than Tmw1, and it is preferable to set it as 50 degrees C or less. More preferably, the temperature is 10 ° C. or higher and 40 ° C. or lower, more preferably 15 ° C. or higher and 35 ° C. or lower. The functions of a plurality of waxes can be efficiently separated, and there is an effect of achieving both low-temperature fixing properties, high-temperature non-offset properties, and paper separation properties. When the temperature is lower than 5 ° C., the effect of achieving both low-temperature fixability, high-temperature non-offset property, and separation property of the copy paper from the fixing roller tends to be difficult to obtain. When the temperature is higher than 50 ° C., the first wax and the second wax are phase-separated and tend not to be uniformly incorporated in the toner particles.
The preferred first wax contains at least one ester composed of at least one of a higher alcohol having 16 to 24 carbon atoms and a higher fatty acid having 16 to 24 carbon atoms. By using this wax, the aliphatic hydrocarbon wax is not taken into the core particles, the presence of wax particles floating and remaining in water is suppressed, and the particle size distribution of the core particles is prevented from becoming broad, Furthermore, it is possible to alleviate the phenomenon that the core particles rapidly become coarse when shelled. Moreover, low temperature fixing can be promoted. The combined use with the second wax improves the high temperature non-offset property and separability of the copy paper from the fixing roller and prevents coarsening of the particle size, and enables generation of core particles having a small particle size and a narrow particle size distribution.
As alcohol components, in addition to monoalcohols such as methyl, ethyl, propyl or butyl, glycols such as ethylene glycol or propylene glycol or multimers thereof, triols such as glycerin or multimers thereof, and polyhydric alcohols such as pentaerythritol Sorbitan or cholesterol is preferred. When the alcohol component is a polyhydric alcohol, the higher fatty acid may be a mono-substituted product or a poly-substituted product.
Specifically, esters comprising a higher alcohol having 16 to 24 carbon atoms and a higher fatty acid having 16 to 24 carbon atoms, such as stearyl stearate, palmityl palmitate, behenyl behenate or stearyl montanate,
Esters comprising a higher fatty acid having 16 to 24 carbon atoms such as butyl stearate, isobutyl behenate, propyl montanate or 2-ethylhexyl oleate and a lower monoalcohol,
Montanic acid monoethylene glycol ester, ethylene glycol distearate, monostearic acid glyceride, monobehenic acid glyceride, tripalmitic acid glyceride, pentaerythritol monobehenate, pentaerythritol dilinoleate, pentaerythritol trioleate or pentaerythritol tetrastearate, etc. Esters comprising a higher fatty acid having 16 to 24 carbon atoms and a polyhydric alcohol, or
Higher fatty acids having 16 to 24 carbon atoms and polyhydric alcohols such as diethylene glycol monobehenate, diethylene glycol dibehenate, dipropylene glycol monostearate, distearic diglyceride, tetrastearic acid triglyceride, hexabehenic acid tetraglyceride or decastearic acid decaglyceride Preferable examples include esters composed of multimers. These waxes may be used alone or in combination of two or more.
When the alcohol component and / or the acid component has less than 16 carbon atoms, the function as a dispersion aid is hardly exhibited, and when it exceeds 24, the function as a low-temperature fixing aid is hardly exhibited.

A preferred first wax includes a wax having an iodine value of 25 or less and a saponification value of 30 to 300. By using together with the second wax, it is possible to prevent the core particles from becoming coarse and to produce core particles having a small particle size and a narrow particle size distribution. By defining the iodine value, the effect of improving the dispersion stability of the wax can be obtained, the core particles can be formed uniformly with the resin particles and the pigment particles, and the core particles with a small particle size and a narrow particle size distribution can be formed. To do. The iodine value is preferably 20 or less, the saponification value is 30 to 200, more preferably the iodine value is 10 or less, and the saponification value is 30 to 150.
If the iodine value is larger than 25, the core particles cannot be uniformly formed with the resin particles and the pigment particles. Wax is not taken into the core particles, and the wax particles floating and remaining in water increase. It tends to become coarse and have a broad particle size distribution. When the saponification value is less than 30, it becomes difficult to form uniform core particles having a small particle diameter, and the chargeability of the toner is lowered, and the chargeability during continuous use tends to be lowered. If it exceeds 300, suspended matter in the aqueous system increases, and fog and toner scattering tend to increase.

  It is preferable that the heat loss at 220 ° C. of the wax having a defined iodine value and saponification value is 8% by weight or less. If the loss on heating is more than 8% by weight, the glass transition point of the toner is lowered and the storage stability of the toner tends to be impaired. Further, it adversely affects the development characteristics, and tends to cause fogging and photoconductor filming. The particle size distribution of the generated toner tends to be broad.

    The first wax is preferably a material such as a meadow foam oil derivative, carnauba wax derivative, jojoba oil derivative, wood wax, beeswax, ozokerite, carnauba wax, canderia wax, ceresin wax or rice wax. Derivatives are also preferably used. One type or a combination of two or more types can be used.

  As the meadow foam oil derivative, meadow foam oil fatty acid, metal salt of meadow foam oil fatty acid, meadow foam oil fatty acid ester, hydrogenated meadow foam oil or meadow foam oil triester can be preferably used. An emulsion dispersion having a small particle size and a uniform particle size distribution can be prepared. It is a preferable material that is effective for low-temperature fixability in oilless fixing, prolonging the life of the developer, and improving transferability. These can be used alone or in combination of two or more.

  The meadow foam oil fatty acid obtained by saponification and decomposition of meadow foam oil is preferably composed of a fatty acid having 4 to 30 carbon atoms. As the metal salt, a metal salt such as sodium, potassium, calcium, magnesium, barium, zinc, manganese or aluminum can be used. High temperature non-offset property is good.

  Meadowfoam oil fatty acid esters include, for example, esters such as methyl, ethyl, butyl, glycerin, pentaerythritol, polypropylene glycol, or trimethylolpropane, and in particular, meadow foam oil fatty acid pentaerythritol monoester, meadowfoam oil fatty acid pentaerythritol triester. Ester or meadow foam oil fatty acid trimethylolpropane ester is preferred. Effective for low-temperature fixability.

  Hydrogenated Meadowfoam oil is obtained by hydrogenating Meadowfoam oil to make unsaturated bonds saturated bonds. Low temperature fixability and glossiness can be improved.

  As jojoba oil derivatives, jojoba oil fatty acid, metal salt of jojoba oil fatty acid, jojoba oil fatty acid ester, hydrogenated jojoba oil, jojoba oil triester, maleic acid derivative of epoxidized jojoba oil, isocyanate of jojoba oil fatty acid polyhydric alcohol ester Polymers and halogenated modified jojoba oil can also be preferably used. An emulsion dispersion having a small particle size and a uniform particle size distribution can be prepared. Easy mixing and dispersion of resin and wax. It is a preferable material that is effective for low-temperature fixability in oilless fixing, prolonging the life of the developer, and improving transferability. These can be used alone or in combination of two or more.

  Jojoba oil fatty acid obtained by saponifying and decomposing jojoba oil consists of fatty acids having 4 to 30 carbon atoms. As the metal salt, a metal salt such as sodium, potassium, calcium, magnesium, barium, zinc or aluminum can be used. High temperature non-offset property is good.

  Examples of jojoba oil fatty acid esters include methyl, ethyl, butyl, glycerin, pentaerythritol, polypropylene glycol, trimethylolpropane and the like, and in particular, jojoba oil fatty acid pentaerythritol monoester, jojoba oil fatty acid pentaerythritol triester, jojoba Oil fatty acid trimethylolpropane ester and the like are preferable. Effective for low-temperature fixability.

Hydrogenated jojoba oil is obtained by hydrogenating jojoba oil to make unsaturated bonds saturated bonds. Effective for improving low-temperature fixability and gloss.
As the second wax, an aliphatic hydrocarbon wax such as polypropylene wax, polyethylene wax, polypropylene polyethylene copolymer wax, microcrystalline wax, paraffin wax or Fischer-to-push wax can be preferably used.

  The saponification value refers to the number of milligrams of potassium hydroxide required to saponify 1 g of a sample. In the case of a wax, the alkali amount necessary for cleaving the ester bond is the saponification value, and a wax having a high saponification value means that the number of ester bonds is large. It is considered that there are many hydrocarbons. To determine the saponification value, a sample is saponified in an alcohol solution of about 0.5 N potassium hydroxide.

  The iodine value refers to the amount of halogen absorbed when halogen is allowed to act on a sample, and expressed in terms of g relative to 100 g of the sample. It is the number of grams of iodine absorbed, and the higher this value, the higher the degree of unsaturation of the fatty acid in the sample. Add iodine and mercury (II) chloride alcohol solution or iodine glacial acetic acid solution to chloroform or carbon tetrachloride solution of the sample, and titrate the remaining iodine without reacting with sodium thiosulfate standard solution to absorb iodine Calculate the amount.

For the measurement of the loss on heating, the weight of the sample cell is precisely weighed to 0.1 mg (W1 mg), 10 to 15 mg of the sample is put in this, and it is precisely weighed to 0.1 mg (W2 mg). The sample cell is set on a differential thermobalance, the measurement is started with a weighing sensitivity of 5 mg. After the measurement, the weight loss when the sample temperature reaches 220 ° C. is read to 0.1 mg by the chart (W3 mg). The apparatus is TGD-3000 manufactured by Vacuum Riko Co., Ltd., the heating rate is 10 ° C./min, the maximum temperature is 220 ° C., the holding time is 1 min, and the heating loss (%) = W 3 / (W 2 −W 1) × 100. .
Measurement of endothermic peak temperature (melting point ° C) and onset temperature of wax by DSC uses TA Instruments, Q100 type (use a genuine electric refrigerator for cooling), measurement mode is “standard”, purge gas (N2) The flow rate is 50 ml / min, the power is turned on, the temperature in the measurement cell is set to 30 ° C., and the sample is left in that state for 1 hour. The aluminum pan containing the sample was put into the measuring instrument. Thereafter, the temperature was maintained at 5 ° C. for 5 minutes, and the temperature was increased to 150 ° C. at a temperature increase rate of 1 ° C./min. For the analysis, “Universal Analysis Version 4.0” attached to the apparatus was used. In the graph, the abscissa represents the temperature in the tank, the ordinate represents the heat flow, the temperature at which the endothermic curve starts to rise from the baseline was the onset temperature, and the peak value of the endothermic curve was the endothermic peak temperature (melting point).
(3) Core or shell agglomeration step The toner production method according to the present invention comprises at least a resin particle dispersion in which resin particles are dispersed, a pigment particle dispersion in which pigment particles are dispersed, and wax particles in an aqueous medium. A step of mixing the dispersed wax particle dispersion to generate a mixed solution, and a step of adding a flocculant to the mixed solution to aggregate resin particles, pigment particles and wax particles to generate colored particles. A toner manufacturing method.
The pigment particles include at least a quinacridone pigment and a naphthol pigment, and have the above-described characteristics.
In the toner production method of the present invention, the pH of the mixed dispersion obtained by mixing the resin particle dispersion, the pigment particle dispersion, and the wax particle dispersion in an aqueous medium is adjusted to a range of 9.5 to 12.2. It is preferable. The pH is preferably adjusted to 10 to 11.5, and more preferably adjusted to the range of 10.5 to 11. The pH can be adjusted by adding 1N NaOH.
By setting the pH value to 9.5 or more, it is possible to suppress the generation of wax particles and pigment particles that are released without being aggregated, and to form core particles having a small particle size and a narrow particle size distribution. By setting the pH value to 12.2 or less, it is possible to form core particles having a small particle diameter in which each particle is uniformly dispersed without being coarsened.
Thereafter, a water-soluble inorganic salt is added to the mixed dispersion, and heat treatment is performed at a temperature higher than the glass transition temperature (Tg) of the resin particles and / or higher than the melting point of the wax, whereby at least resin particles, pigment particles, and wax particles are obtained. Core particles having a predetermined volume average particle diameter, at least partially melted and aggregated, are formed.
The pH of the liquid when the core particles having the predetermined volume average particle diameter are formed is preferably maintained in the range of 7.0 to 9.5, whereby the release of pigment particles and wax particles is small, There is an effect that core particles in which particles are uniformly dispersed can be obtained.
The amount of NaOH to be added, the type and amount of flocculant, the pH of the emulsion polymerization resin dispersion, the pH of the pigment dispersion, the pH of the wax dispersion, the heating temperature, and the time are appropriately selected. If the pH of the liquid when the particles are formed is less than 7.0, the amount of pigment or wax released due to poor aggregation increases, and as a result of the time required for aggregation, the generated core particles tend to increase. When the pH exceeds 9.5, the core particles tend to become coarse. In addition, secondary aggregation between core particles tends to occur.

For the measurement of pH (hydrogen ion concentration), 10 ml of a sample to be measured is collected from the liquid tank using a pipette and placed in a beaker having the same volume. This beaker is immersed in cold water, and the sample is cooled to room temperature (30 ° C. or lower). Using a pH meter (Seven Multi: manufactured by METTLER TOLEDO), immerse the measurement probe in the sample cooled to room temperature. When the meter display is stable, read the value and use it as the pH value.
The heating rate of the mixed dispersion is preferably from 0.1 to 10 ° C./min. When it is slower than 0.1 ° C./min, the productivity is lowered. If it is faster than 10 ° C./min, the shape tends to advance too spherically before the particle surface becomes smooth.
It is preferable that 1 to 50 parts by weight of the flocculant is dropped with respect to 100 parts by weight of the total of the resin particles, pigment particles and wax particles. Preferably it is 5-20 weight part, More preferably, it is 5-15 weight part. When the amount of the flocculant is less than 1 part by weight, the aggregation reaction does not proceed. When the amount is more than 50 parts by weight, the generated particles tend to be coarse.
The toner production method of the present invention preferably further includes a step of shifting the pH in the core particle dispersion liquid in which the core particles in which the resin particles, pigment particles and wax particles are aggregated is dispersed to 0.5 to 5 acid side. .
After the core particles having a certain particle diameter are formed, the core particles can be prevented from becoming coarse even if the heat treatment is continued for 1 to 3 hours by further adjusting the pH. The surface of the core particle can be made smoother, and the shape can be made close to a spherical shape. Moreover, the effect which accelerates | stimulates adhesion of shell resin in the following process is acquired.
The pH in the liquid when core particles having a certain particle diameter are formed is in the range of 7.0 to 9.5, and is further shifted 0.5 to 5 to the acidic side, so that the pH is 2 to 9 It is preferable to shift to this range.
Preferably, the pH is shifted 1.5 to 4 to the acidic side and the pH is shifted to 3 to 8, more preferably the pH is shifted to 2 to 3 and the pH is preferably shifted to 4 to 7.5.
(4) Shell agglomeration step In the toner production method of the present invention, the core particle dispersion in which the core particles are dispersed is added and mixed with the shell resin particle dispersion in which the shell resin particles are dispersed. A configuration in which the toner base particles are generated by fusing the shell resin particles to the core particles is also preferable. In this case, the resin particles used for the core particles may be referred to as first resin particles or core resin particles.
By forming a fused layer of shell resin particles on the surface of the core particles, an effect on stabilization of charging can be obtained (sometimes referred to as a shell layer). In addition, from the viewpoint of improving the storage stability of the toner at a high temperature, resin particles having a high glass transition point (Tg (° C.)) are used, and from the viewpoint of ensuring offset resistance at high temperatures, high-molecular weight emulsified resin fine particles are used. From the viewpoint of charging stability, it is desirable to form resin particles containing a charge control agent as a shell layer.
As a condition for dropping the shell resin particle dispersion into the core particle dispersion, the dropping rate of the shell resin particles is 0.14 parts by weight / min to 2 parts by weight / min with respect to 100 parts by weight of the generated core particles. The structure which produces | generates by dripping on dripping conditions is preferable. Preferably it is 0.15 weight part / min-1 weight part / min, More preferably, it is 0.2 weight part / min-0.8 weight part / min.
The addition time of the shell resin particle dispersion is added as it is when the core particles reach a predetermined particle size. The addition is preferably carried out by dropping a constant amount quantitatively continuously. When the predetermined total amount is added all at once or exceeds 2 parts by weight / min, only the shell resin particles tend to aggregate and the particle size distribution tends to be broad. In addition, when the input amount is increased, the liquid temperature rapidly decreases and the agglomeration reaction stops, and a part of the shell resin particles remain floating in the aqueous system without being attached to the core particles. May end up.
On the other hand, when the amount is less than 0.14 parts by weight / min, the amount of the shell resin particles adhered to the core particles per unit time is reduced, and when the heating is continued, the core particles are aggregated, Particles become coarse and particle size distribution tends to be broad.
By optimizing the dropping conditions of the shell resin particle dispersion, aggregation of the core particles or aggregation of only the shell resin particles can be prevented, thereby enabling generation of particles having a small particle size and a narrow particle size distribution.
A configuration in which the shell resin particle dispersion is dropped so as to suppress the fluctuation of the liquid temperature of the core particle dispersion in which the produced core particles are dispersed within 10% is preferable.
In the configuration in which the shell resin particles are fused to the core particles, the shell resin particle dispersion in which the shell resin particles are dispersed is added to the core particle dispersion, and heat treatment is performed on the core particles, and the shell resin particles on the core particles. As a condition for forming the resin fusion layer to be fused, it is preferable to add after adjusting the pH value of the shell resin particle dispersion to a certain range.
By adjusting the pH value of the shell resin particle dispersion to a certain range and adding the shell resin particle dispersion, the generation of shell resin particles floating and remaining in water without being fused to the core particles is suppressed, and the core particles are dispersed. The aim is to improve the fusion of the shell resin particles, or to suppress the occurrence of secondary aggregation between the core particles.
In the configuration in which the pH value of the shell resin particle dispersion is adjusted to a certain range, the pH value of the shell resin particle dispersion adjusted to an alkaline state is preferably in the range of 7.5 to 10.5. Preferably it is 8.5-10, More preferably, it is 9-9.5. By adjusting the shell resin particle dispersion to the above-described alkaline state, generation of white particles in which the shell resins are aggregated and generation of secondary particles in which the core particles are aggregated are suppressed, and the shell resin is fused to the core particles. The effect of promoting wearing is obtained.
Moreover, it is preferable to add the shell resin particle dispersion liquid in which the shell resin particles whose pH value is adjusted to an alkaline state is dispersed to the core particle dispersion liquid having a pH value of 7 or less and 2 or more. By adjusting the pH value of the core particle dispersion to the above-described range, the fusion of the shell resin particles to the core particles is promoted, and the generation of shell resin particles floating and remaining in the water without being fused to the core particles is suppressed. It is possible to form a narrow particle size distribution with a small particle size by suppressing the occurrence of secondary aggregation between the core particles. Moreover, when the pH value of the core particle dispersion is set to 7 or less to be in an acidic state, for example, when magnesium sulfate is used as the flocculant, the effect of removing the remaining magnesium hydroxide can be obtained. If magnesium hydroxide remains, the toner tends to absorb moisture when left under high humidity, so it is also aimed to suppress absorption.
Furthermore, by having a certain relationship between the pH value of the shell resin particle dispersion and the pH value of the core particle dispersion, the balance of the pH in the aqueous system is partially disturbed, so that the shell resin particles to the core particles The aim is to promote the fusion of the core particles, suppress the generation of shell resin particles that remain floating and remain in the water without being fused to the core particles, and further suppress the occurrence of secondary aggregation between the core particles.
The pH value of the core particle dispersion is in the range of 7 or less and 2 or more, and the pH value of the shell resin particle dispersion is adjusted to 7.5 to 10.5 and then added, whereby the shell resin particles are added to the core particles. Promotes fusion, suppresses the generation of shell resin particles that float and remain in water without fusing to the core particles, suppresses the occurrence of secondary aggregation between the core particles, and forms a narrow particle size distribution with a small particle size It becomes possible.
When the pH value of the core particle dispersion is smaller than 2 and the pH value of the shell resin particle dispersion is smaller than 7.5, the adhesion of the shell resin particles to the core particles does not proceed, and the shell resin particles become the core particles. There is a tendency to remain in a floating state without fusing. When the pH value of the core particle dispersion is greater than 7 and the pH value of the shell resin particle dispersion is greater than 10.5, the adhesion of the shell resin particles to the core particles does not proceed, and the produced particles It tends to be coarse. The pH value can be adjusted by adding sodium hydroxide or hydrochloric acid solution.

It is preferable to maintain the pH value of the shell resin particle dispersion and the core particle dispersion in a certain relationship, and the pH value of the shell resin particle dispersion in which the shell resin particles are dispersed is the core particle dispersion in which the core particles are dispersed. It is preferable to adjust the pH to a value higher than the pH value, that is, to be added in an alkaline state.
The pH value of the shell resin particle dispersion in which the shell resin particles are dispersed is preferably 0.5 or more higher than the pH value of the core particle dispersion in which the core particles are dispersed. More preferably, it is 1 or more, More preferably, it is 2 or more, Preferably it is 5 or less. When it is smaller than 0.5, there is a tendency that the generation of shell resin particles that remain floating in water without being fused to the core particles tends to increase. Conversely, when the difference exceeds 5, the secondary agglomeration between the core particles occurs, and the generated particles tend to be coarse.
Even when the pH value of the shell resin particle dispersion in which the shell resin particles are dispersed is lower than the pH value of the core particle dispersion in which the core particles are dispersed, the generation of shell resin particles that are not fused to the core particles increases. The liquid continues to be cloudy.
Further, after the shell resin particles are adhered to the surface of the core particles, the pH in the aqueous system is further adjusted to the range of 3.2 to 6.8, and then the temperature is 0.5 or higher at a temperature equal to or higher than the glass transition temperature of the shell resin particles. It is also preferable to employ a method of heat treatment for ˜5 hours. By setting the pH within this range, it is possible to further promote the surface smoothness of the particle shape while suppressing secondary aggregation between the core particles. In addition, in a system using magnesium sulfate, which is a water-soluble inorganic salt added as a flocculant, magnesium hydroxide produced by the progress of the agglomeration reaction in a partially alkaline state is oxidized in an acid state to be removed as water-soluble. As a result, the effect of reducing moisture absorption, which is a phenomenon in which the toner easily absorbs water, can also be obtained.
In order to improve the durability, storage stability, and high temperature non-offset property of the toner, the thickness of the resin layer fused with the shell resin particles is preferably 0.5 μm to 2 μm. When the thickness of the resin layer is less than 0.5 μm, the effects of storage stability and high temperature non-offset properties are not exhibited, and when it is thicker than 2 μm, the low temperature fixability is inhibited.
It is preferable that the main component of the surfactant used in the core resin particle dispersion or the shell resin particle dispersion is a nonionic surfactant. Further, the surfactant is composed of a nonionic surfactant and an ionic surfactant. A composition to be mixed is also preferable, and the configuration at this time is preferably such that the nonionic surfactant has 50 to 95 wt% with respect to the entire surfactant. More preferably, it is 55-90 wt%, More preferably, it is preferable to have 60-85 wt%. By setting it to 50 wt% or more, adhesion of the shell resin particle fine particles to the core particles can be promoted. By setting it to 95 wt% or less, there is an effect of stabilizing the dispersion of the resin particles themselves in the resin particle dispersion.
A glass-lined SUS kettle as a preferred reaction kettle used for the agglomeration reaction is not particularly limited as an agitation blade for agitating the dispersion, but a blade shape having a wide width in the depth direction (flat blade) is used. It is valid. As the flat plate wing, a trade name Max Blend wing manufactured by Sumitomo Heavy Industries, Ltd. or a full zone wing manufactured by Shinko Pantech Co., Ltd. is effective.
FIG. 7 is a schematic diagram showing the configuration of the Max Blend wing, and FIG. 8 is a plan view seen from above. Moreover, the structure of a full zone blade | wing is shown in the schematic in FIG. 9, and the top view seen from the top in FIG. A shaft 301 is connected to a stirring motor (not shown). 302 is a stirring tank, 303 is a water surface of the liquid, 304 is a flat max blend blade, and 305 holes are provided in the blade to adjust the stirring strength of the liquid. Reference numeral 306 denotes a flat rectangular blade, and a stirring blade 307 is provided below the flat rectangular blade. The tip is bent about 130 degrees. Reference numeral 308 denotes the length of the stirring blade.
The rotational speed of the stirring blade varies depending on the particle concentration in the dispersion and the target particle size, but is preferably 0.5 to 2.0 m / s. More preferably, it is 0.7-1.8 m / s, More preferably, it is 1.0-1.6 m / s. When the speed is too low than 0.5 m / s, the particle size of the generated particles tends to be large and the particle size distribution tends to be widened. On the other hand, when the speed is higher than 2.0 m / s, the aggregation of the particles is hindered, the shape is likely to be indefinite, and it is difficult to generate particles.

After the particles are formed in the aqueous system, toner base particles can be obtained through an arbitrary washing step, solid-liquid separation step, and drying step. In this cleaning step, it is preferable to perform cleaning with ion-exchanged water from the viewpoint of improving the chargeability. A method of washing using an acid and an alkali is also preferable.
There is no restriction | limiting in particular as a separation method in a solid-liquid separation process, From a viewpoint of productivity, well-known filtration methods, such as a suction filtration method and a pressure filtration method, are mentioned preferably.
There is no restriction | limiting in particular as a drying method in a drying process, From a viewpoint of productivity, well-known drying methods, such as a flash jet drying method, a fluidized drying method, and a vibration type fluidized drying method, are mentioned preferably.

As the flocculant, a water-soluble inorganic salt is selected, and examples thereof include alkali metal salts and alkaline earth metal salts. Examples of the alkali metal include lithium, potassium, and sodium, and examples of the alkaline earth metal include magnesium, calcium, strontium, and barium. Of these, potassium, sodium, magnesium, calcium, and barium are preferable. Examples of the counter ion (anion constituting the salt) of the alkali metal or alkaline earth metal include chloride ion, bromide ion, iodide ion, carbonate ion and sulfate ion. It is also preferable to use it after adjusting it to a certain concentration with ion exchange water or the like.
Examples of the aqueous medium include water such as distilled water and ion exchange water, and alcohols. These may be used individually by 1 type and may use 2 or more types together. The content of the polar surfactant in the dispersant having the polarity cannot be generally defined and can be appropriately selected according to the purpose.
Nonionic dispersants (nonionic surfactants) include higher alcohol ethylene oxide adducts, alkylphenol ethylene oxide adducts, fatty acid ethylene oxide adducts, polyhydric alcohol fatty acid ester ethylene oxide adducts, fatty acid amide ethylene oxide adducts, Polyalkyl alcohol alkyl ethers, fats and oils ethylene oxide adducts, polyethylene glycol type nonionic surfactants such as polypropylene glycol ethylene oxide adducts, glycerol fatty acid esters, pentaerythritol fatty acid esters, sorbitol and sorbitan fatty acid esters, Polyhydric alcohol type nonionic surfactants such as fatty acid esters of sucrose, alkyl ethers of other alcohols, fatty acid amides of alkanolamines, etc. And the like.
(5) Pigment Pigment Red (PR) 122, 202, and 209 can be preferably used as the quinacridone pigment in the toner of the present invention or the toner production method. PR122 is more preferable.
As the naphthol pigment, pigment red (PR) 146, 147, 176, 238, 269 can be preferably used. PR269 is more preferred.
The yellow pigment is C.I. I. Acetoacetic acid arylamide monoazo yellow pigments such as C.I. Pigment Yellow 1, 3, 74, 97 or 98; I. Acetoacetic acid arylamide disazo yellow pigments such as C.I. Pigment Yellow 12, 13, 14, and 17; I. Solven Yellow 19, 77, 79 or C.I. I. Disperse Yellow 164 is blended, and C.I. I. Benzimidazolone pigments of CI Pigment Yellow 93, 180 and 185 are preferred.
The cyan pigment is C.I. I. A blue dyed pigment of phthalocyanine and its derivatives such as Pigment Blue 15: 3 can be preferably used. The addition amount is preferably 3 to 8 parts by weight with respect to 100 parts by weight of the binder resin.
When carbon black is used as the pigment of the black toner, it is preferable that carbon black has a DBP (dibutyl phthalate) oil absorption of 45 to 70 (ml / 100 g). Preferably it is 45-63, More preferably, it is 45-60, More preferably, it is 45-53. Carbon black smaller than 45 has not produced a suitable sample.
By using carbon black having a DBP oil absorption of 45 to 70 (ml / 100 g), the tendency of carbon black aggregation to proceed abnormally quickly is mitigated, and the carbon black particles tend to be easily incorporated into the core particles. is there. Moreover, when it is set as the shell structure which adhered the shell resin particle to the core particle mentioned later, it exists in the tendency for the BET specific surface area value by nitrogen adsorption | suction of a production | generation particle to become small. As a result, fog that is toner adhesion to the non-image area during development tends to be reduced. It is considered that the dispersion state of carbon black affects the surface state.
Carbon black has characteristics close to inorganic, compared to other organic pigments such as phthalocyanine, quinacridone, and azo, and its aggregating properties (particles when aggregating agent is added) Tend to be different. Therefore, it seems preferable to use carbon black having a certain oil absorption characteristic in carbon black.
In addition, in the use of a wax having a certain melting point, by defining the DBP oil absorption characteristics of the carbon black particles in the agglomeration reaction between the molten wax and the carbon black particles in the powder state, the carbon black particles become the core particles. The effect of eliminating carbon black particles that are taken in and remain in the core particle dispersion without being aggregated is obtained. Moreover, the effect of suppressing the phenomenon that the fixability function of the wax is lowered can be obtained.

For example, Mitsubishi Chemical Corporation # 52 (particle size 27 nm, DBP oil absorption 63 ml / 100 g), # 50 (28 nm, 65 ml / 100 g), # 47 (23 nm, 64 ml / 100 g), # 45 (same as above) 24 nm, 53 ml / 100 g), # 45L (24 nm, 45 ml / 100 g), Cabot REGAL 250R (35 nm, 46 ml / 100 g), REGAL 330R (25 nm, 65 ml / 100 g), MOGULL (24 nm) , 60 ml / 100 g). More preferred are # 45, # 45 and REGAL250R. The particle diameter is the average diameter observed by SEM electron microscope. The particle size of carbon black is preferably 20 to 40 nm. Preferably, it is 20-35 nm. When the particle diameter is larger than 40 nm, the coloring power tends to decrease. When the particle diameter is 20 nm smaller, dispersion in the liquid tends to be difficult.
The DBP oil absorption is a quantitative representation of the chain aggregate state (structure) of the particles, and is represented by a primary structure by chemical bonding and a secondary structure by physical bonding by van der Waals force.
DBP oil absorption (JISK6217) was measured by putting 20 g (Ag) of sample dried at 150 ° C. ± 1 ° C. for 1 hour into a mixing chamber of an absorber meter (manufactured by Brabender, spring tension 2.68 kg / cm), After setting the limit switch to about 70% of the maximum torque in advance, the mixer is rotated. DBP (specific gravity 1.045~1.050g / cm ³⁾ is added at a rate of 4 ml / min from the automatic burette at the same time. As the end point is approached, the torque increases rapidly and the limit switch is turned off. The DBP oil absorption (= Bx100 / A) (ml / 100 g) per 100 g of the sample is determined from the DBP amount (Bml) added so far and the sample weight.
(6) Resin Examples of the resin fine particles of the toner according to the exemplary embodiment include a thermoplastic binder resin. Specifically, styrenes such as styrene, parachlorostyrene, and α-methylstyrene, acrylic monomers such as methyl acrylate, ethyl acrylate, n-propyl acrylate, lauryl acrylate, and 2-ethylhexyl acrylate , Methacrylic monomers such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, carboxyl groups such as acrylic acid, methacrylic acid, maleic acid, fumaric acid Homopolymers such as unsaturated polyvalent carboxylic acid monomers, and the like, copolymers obtained by combining two or more of these monomers, and mixtures thereof.
As polymerization initiators, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2 , 2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile and other azo or diazo polymerization initiators, persulfates (potassium persulfate, ammonium persulfate, etc.), azo compounds (4,4′-azobis-4-cyanovaleric acid and salts thereof, 2,2′-azobis (2-amidinopropane) salt, etc.), peroxide compounds and the like.

The content of the resin particles in the resin particle dispersion is usually 5 to 50% by weight, preferably 10 to 40% by weight.
In order to form particles having a narrow particle size distribution, it is preferable that the core resin particles have a glass transition point of 45 ° C to 60 ° C and a softening point of 90 ° C to 140 ° C. More preferably, the glass transition point is 45 ° C to 55 ° C, the softening point is 90 ° C to 135 ° C, and still more preferably, the glass transition point is 45 ° C to 52 ° C, and the softening point is 90 ° C to 130 ° C. preferable.
The core resin particles preferably have a weight average molecular weight (Mw) of 10,000 to 60,000 and a weight average molecular weight (Mw) to number average molecular weight (Mn) ratio Mw / Mn of 1.5 to 6. It is preferable that the weight average molecular weight (Mw) is 10,000 to 50,000 and the ratio Mw / Mn of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 1.5 to 3.9. More preferably, the weight average molecular weight (Mw) is 10,000 to 30,000, and the ratio Mw / Mn of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 1.5 to 3. It is possible to prevent coarsening of the core particles and efficiently generate particles having a narrow particle size distribution. In addition, low-temperature fixability is possible, and further, there is an effect that the image gloss can be made constant by reducing the change of the image gloss to the fixing temperature.
When the glass transition point of the resin particles is smaller than 45 ° C., the core particles are coarsened. Storage stability and heat resistance are reduced. When it is higher than 60 ° C., the low-temperature fixability deteriorates. When Mw is smaller than 10,000, the core particles become coarse. Storage stability and heat resistance are reduced. If it exceeds 60,000, the low-temperature fixability deteriorates. When Mw / Mn is larger than 6, the shape of the core particles is not stable, tends to be indefinite, and irregularities remain on the particle surfaces, resulting in poor surface smoothness.

The core resin particles are preferably 60 wt% or more, more preferably 70 wt% or more, still more preferably 80 wt% or more with respect to the total toner resin.
Moreover, in the structure which fuse | melts a shell resin particle to a core particle and forms a resin melt | fusion layer, as a characteristic of the shell resin particle, a glass transition point is 55 to 75 degreeC, and a softening point is 140 to 180 degreeC. The weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) is 50,000 to 500,000, and the ratio Mw / Mn of the weight average molecular weight (Mw) and the number average molecular weight (Mn) is 2 to 10. Is preferred. More preferably, the glass transition point is 60 ° C to 70 ° C, the softening point is 145 ° C to 180 ° C, the Mw is 80,000 to 500,000, and the Mw / Mn is 2 to 7. More preferably, the glass transition point is 65 ° C to 70 ° C, the softening point is 150 ° C to 180 ° C, Mw is 120,000 to 500,000, and Mw / Mn is 2 to 5.
The aim is to improve the durability, high-temperature offset resistance, and separation between the copy paper and the fixing roller by promoting fusion to the surface of the core particles and increasing the softening point. If the glass transition point of the shell resin particles is lower than 55 ° C., secondary aggregation tends to occur. Moreover, storage stability deteriorates. When it is higher than 75 ° C., the heat-fusibility to the core particle surface is lowered, and the uniform adhesion is lowered. When the softening point of the shell resin particles is lower than 140 ° C., durability, high-temperature offset resistance, and separation properties are deteriorated. When it is higher than 180 ° C., glossiness and translucency are lowered. By making Mw / Mn small and making the molecular weight distribution close to monodisperse, the thermal fusion of the shell resin particles to the surface of the core particles can be performed uniformly. When the Mw of the shell resin particles is less than 50,000, durability, high temperature non-offset property, and separation between the copy paper and the fixing roller are deteriorated. If it exceeds 500,000, the low-temperature fixability, glossiness, and translucency are lowered.

  The molecular weights of the polymer dispersant, resin, wax and toner are values measured by gel permeation chromatography (GPC) using several types of monodisperse polystyrene as standard samples.

The apparatus is HLC8120GPC series manufactured by Tosoh Corporation, the column is TSKgel super HM-H H4000 / H3000 / H2000 (6.0 mm ID-150 mm × 3), eluent THF (tetrahydrofuran), flow rate 0.6 mL / min, sample concentration 0 .1%, injection amount 20 μL, detector RI, measurement temperature 40 ° C., pre-measurement treatment was performed by dissolving the sample in THF and allowing it to stand overnight, followed by filtration through a 0.45 μm membrane filter to remove additives such as silica. The resin component is measured. The measurement conditions are conditions in which the molecular weight distribution of the target sample is included in a range in which the logarithm of the molecular weight and the count number are linear in a calibration curve obtained with several types of monodisperse polystyrene standard samples.
The softening point of the polymer dispersant and the binder resin is measured by a constant load extrusion type capillary rheometer flow tester (CFT500) manufactured by Shimadzu Corporation.
First, a sample is filled in a cylinder, heated from the surroundings and melted, and a certain pressure is applied from above by a piston. The molten sample is extruded through a die having a narrow hole (diameter 1 mm, length 1 mm), and the fluidity of the sample, that is, the melt viscosity is determined from the flow rate (cm ³ / g).
First, a heating furnace surrounding the cylinder and die is provided and set to 50 ° C. Fill the cylinder with 1 g of sample. Hold at 50 ° C. for 2.5 min without applying load. A load is applied to remove air from the sample. At this time, the length of the piston coming out of the heating furnace is set to about 12 to 15 mm. When the total holding time reaches 5 min, the temperature rise is started.

A load of 9.8 × 10 ⁵ N / m ² is applied to the piston, and the piston is heated at a heating rate of 6 ° C./min. When the sample starts to melt, the downward movement of the piston begins. When the movement of the piston stops, the temperature rise and pressurization are stopped.

At this time, the viscosity at each temperature can be measured from the relationship with the temperature rise temperature characteristic in the relationship between the moving amount of the descending piston and the temperature.
FIG. 11 shows a flow curve. The horizontal axis shows the temperature, and the vertical axis shows the image of the piston movement. At the time of A, it is a region of the solid state of the sample, and as the temperature rises thereafter, A to B are transition regions, and the sample is deformed by receiving a compressive load, and the internal voids gradually decrease. B is a temperature at which the internal voids disappear and a single transparent body having a uniform appearance with a non-uniform stress distribution is obtained.
B to C are regions where there is no clear change in the piston position within a finite time, and it is difficult for the sample to flow out of the die, and this region includes the rubbery elastic region of the sample.
C is defined as a temperature at which the sample starts to flow (outflow start temperature (Tfb)) at a temperature at which the sample starts to flow and the piston starts to descend.
The region from C to D through E is the flow region where the sample clearly flows out of the die, where E is the point where the sample has finished flowing out.
The softening point of the binder resin is defined by the melting temperature in the 1/2 method (softening point Ts ° C.). Specifically, the softening point is defined as the temperature at which the piston moves 50% from the outflow start temperature with respect to the total movement distance of the piston from the outflow start temperature to the outflow end temperature.
11, the temperature at which the piston starts to descend (temperature at which the sample flows) is first measured. This is the outflow start temperature (Tfb). The piston position at this time is read and made the minimum value (Smin).
Thereafter, as the temperature rises, the sample continues to flow out of the die, and the temperature at the outflow end point E at which the outflow of the sample is completed and the position of the piston are read and set as the outflow end point (Smax).
1/2 of the difference between the outflow end point (Smax) and the minimum value (Smin) is obtained (X = (Smax−Smin) / 2), and the temperature at the position of the point D where X and the minimum value Smin of the curve are added is calculated. calculate. This is the melting temperature (softening point Ts ° C.) in the 1/2 method.

Use a differential scanning calorimeter (TA Instruments, Q100 type (a genuine electric refrigerator is used for cooling)) for the glass transition point of the polymer dispersant and binder resin, the measurement mode is “standard”, purge gas ( N2) After turning on the power at a flow rate of 50 ml / min, set the temperature in the measurement cell to 30 ° C, leave it in that state for 1 hour, and put 10 mg ± 2 mg of the sample to be measured as a sample amount in a genuine aluminum pan The aluminum pan containing the sample was put into the measuring instrument. Thereafter, the temperature was maintained at 5 ° C. for 5 minutes, and the temperature was increased to 150 ° C. at a temperature increase rate of 1 ° C./min. For the analysis, “Universal Analysis Version 4.0” attached to the apparatus was used. In the graph, it refers to the temperature at the intersection of the extension of the baseline below the glass transition point and the tangent that indicates the maximum slope from the peak rise to the peak apex.
In measuring the thermal properties of these resins, it is necessary to extract the solid content of the resin particles from the emulsion obtained by emulsion polymerization. As a method for extracting the solid content of the resin particles from the emulsion, a configuration in accordance with the toner aggregation step is performed. First, 2 ml of 1N NaOH is added to 20 g of the emulsion, 6 g of magnesium sulfate and 20 g of ion-exchanged water are added, and then the temperature is raised to 85 ° C. and heated for 1 hour. Thereafter, the mixture is cooled, 0.5 ml of 1N HCl is added, filtered, the precipitated sample is dried, and the molecular weight, softening point, glass transition point, etc. of the obtained polymer are measured.
(7) External additive In this embodiment, inorganic fine powder is mixed and added as an external additive. External additives include silica, alumina, titanium oxide, zirconia, magnesia, ferrite, magnetite and other metal oxide fine powders, barium titanate, calcium titanate, titanates such as strontium titanate, barium zirconate, zircon Zirconates such as calcium acid and strontium zirconate, or mixtures thereof are used. The external additive is hydrophobized as necessary.

Examples of the silicone oil-based material to be treated by the external additive include dimethyl silicone oil, methyl hydrogen silicone oil, methyl phenyl silicone oil, epoxy-modified silicone oil, carboxyl-modified silicone oil, methacryl-modified silicone oil, and alkyl-modified silicone oil. An external additive treated with at least one of fluorine-modified silicone oil, amino-modified silicone oil, and chlorophenyl-modified silicone oil is preferably used. Examples thereof include SH200, SH510, SF230, SH203, BY16-823 or BY16-855B manufactured by Toray Dow Corning Silicone.
For the treatment, the external additive and the material such as silicone oil are mixed with a mixer such as a Henschel mixer (FM20B manufactured by Mitsui Mining Co., Ltd.), the method of spraying the silicone oil-based material onto the external additive, the silicone oil as the solvent There is a method of preparing by dissolving or dispersing a system material, mixing with an external additive, and then removing the solvent. The silicone oil-based material is preferably blended in an amount of 1 to 20 parts by weight per 100 parts by weight of the external additive.

  As silane coupling agents, dimethyldichlorosilane, trimethylchlorosilane, allyldimethylchlorosilane, hexamethyldisilazane, allylphenyldichlorosilane, benzylmethylchlorosilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, Vinyltriacetoxysilane, divinylchlorosilane, dimethylvinylchlorosilane, or the like can be preferably used. The silane coupling agent treatment is a dry treatment in which the vaporized silane coupling agent is reacted with the external additive made into a cloud by stirring or the like, or a silane coupling agent in which the external additive is dispersed in a solvent is dropped. It is processed by a wet method or the like.

  It is also preferable to treat the silicone oil-based material after the silane coupling treatment.

  The external additive having positive electrode chargeability is treated with aminosilane, amino-modified silicone oil or epoxy-modified silicone oil.

  Moreover, in order to improve hydrophobic treatment, the combined use of treatment with hexamethyldisilazane, dimethyldichlorosilane, or other silicone oil is also preferable. For example, it is preferable to treat with at least one of dimethyl silicone oil, methylphenyl silicone oil, and alkyl-modified silicone oil.

Moreover, it is also preferable to treat the surface of the external additive with one or more selected from the group of fatty acid esters, fatty acid amides, fatty acids and fatty acid metal salts (hereinafter referred to as fatty acids). Surface-treated silica or titanium oxide fine powder is more preferable.
Examples of fatty acids or fatty acid metal salts include caprylic acid, capric acid, undecylic acid, lauric acid, myristylic acid, parimitic acid, stearic acid, behenic acid, montanic acid, laccellic acid, oleic acid, erucic acid, sorbic acid or linoleic acid Is mentioned. Of these, fatty acids having 12 to 22 carbon atoms are preferred.

Moreover, as a metal which comprises a fatty-acid metal salt, aluminum, zinc, calcium, magnesium, lithium, sodium, lead, or barium is mentioned, Among these, aluminum, zinc, or sodium is preferable. Particularly preferred are aluminum distearate (Al (OH) (C ₁₇ H ₃₅ COO) ₂ ) or aluminum monostearate (Al (OH) ₂ (C ₁₇ H ₃₅ COO)), etc. Is preferred. Having an OH group can prevent overcharging and suppress poor transfer. Further, it is considered that the processability with the external additive is improved during the treatment.
The aliphatic amide has 16 to 24 carbon atoms such as palmitic acid amide, palmitoleic acid amide, stearic acid amide, oleic acid amide, arachidic acid amide, eicosenoic acid amide, behenic acid amide, erucic acid amide, or ligrinoceric acid amide. Saturated or monovalent unsaturated aliphatic amides are preferably used.
Examples of fatty acid esters include esters comprising higher alcohols having 16 to 24 carbon atoms and higher fatty acids having 16 to 24 carbon atoms such as stearyl stearate, palmityl palmitate, behenyl behenate or stearyl montanate, butyl stearate, Esters consisting of higher fatty acids having 16 to 24 carbon atoms and lower monoalcohols such as isobutyl behenate, propyl montanate or 2-ethylhexyl oleate, or fatty acid pentaerythritol monoester, fatty acid pentaerythritol triester, or fatty acid trimethylol Propane ester or the like is preferably used.
Materials such as hydroxystearic acid derivatives, polyhydric alcohol fatty acid esters such as glycerin fatty acid ester, glycol fatty acid ester or sorbitan fatty acid ester are preferred, and one kind or a combination of two or more kinds can also be used.
As a preferred form of the surface treatment, it is also preferred that the surface of the external additive to be treated is treated with a coupling agent and / or polysiloxane such as silicone oil and then treated with a fatty acid or the like. This is because a uniform treatment is possible as compared with the case where the fatty acid of the hydrophilic silica is simply treated, and the toner can be highly charged and the fluidity when added to the toner is improved. In addition, the above-described effects can be obtained even in a configuration in which a fatty acid or the like is processed together with a coupling agent and / or silicone oil.
Dissolve fatty acid in a hydrocarbon-based organic solvent such as toluene, xylene or hexane, and mix it with an external additive such as silica, titanium oxide, alumina, etc. It is produced by depositing, applying a surface treatment, and then removing the solvent and performing a drying treatment.
The mixing ratio of polysiloxane and fatty acid is preferably 1: 2 to 20: 1. When the ratio is higher than 1: 2, the amount of charge of the external additive increases, and the image density tends to decrease, and charge-up tends to occur in two-component development. If the amount of fatty acid or the like is less than 20: 1, the effect on transfer loss and reverse transferability tends to decrease.
At this time, the ignition loss of the external additive whose surface is treated with fatty acid or the like is preferably 1.5 to 25% by weight. More preferably, it is 5-25 weight%, More preferably, it is 8-20 weight%. When the amount is less than 1.5% by weight, the function of the treating agent is not sufficiently exhibited, and the effect of improving the chargeability and transferability does not appear. If it exceeds 25% by weight, an untreated agent is present, which adversely affects developability and durability.

Unlike the conventional pulverization method, the surface of the toner base particles produced according to the present invention is formed from only a resin, which is advantageous in terms of charge uniformity. This is because compatibility with the external additive used is important.
A configuration in which 1 to 6 parts by weight of an external additive having an average particle diameter of 6 nm to 200 nm is externally added to 100 parts by weight of the toner base particles is preferable. When the average particle diameter is smaller than 6 nm, filming on the suspended particles and the photoreceptor tends to occur. The reverse transfer during transfer tends to occur. If it exceeds 200 nm, the fluidity of the toner tends to deteriorate. When the amount is less than 1 part by weight, the fluidity of the toner tends to deteriorate. Reverse transfer during transfer tends to occur easily. When the amount is more than 6 parts by weight, the floating particles and the filming on the photoreceptor tend to occur easily.

  Further, an external additive having an average particle diameter of 6 nm to 20 nm is added to 0.5 to 2.5 parts by weight with respect to 100 parts by weight of the toner base particles, and an external additive having an average particle diameter of 20 nm to 200 nm is added to 100 parts by weight of the toner base particles. On the other hand, a configuration in which at least 0.5 to 3.5 parts by weight is externally added is also preferable. By using an external additive that is functionally separated by this configuration, the charge imparting property and the charge retention property are improved, and a margin can be further taken against reverse transfer, dropout, and toner scattering during transfer. At this time, the ignition loss of the external additive having an average particle diameter of 6 nm to 20 nm is preferably 0.5 to 20% by weight, and the ignition loss of the average particle diameter of 20 nm to 200 nm is preferably 1.5 to 25% by weight. . By increasing the loss on ignition with an average particle size of 20 nm to 200 nm more than the loss on ignition of an external additive with an average particle size of 6 nm to 20 nm, it is effective for reverse transfer during transfer and voiding. Is demonstrated.

  By specifying the loss on ignition of the external additive, a margin can be taken against reverse transfer, dropout, and scattering during transfer. It is possible to improve the handling property in the developing unit and increase the uniformity of the toner density.

  If the loss on ignition with an average particle size of 6 nm to 20 nm is less than 0.5% by weight, the transfer margin for reverse transfer and hollow out tends to be narrow. If it exceeds 20% by weight, the surface treatment becomes uneven, and there is a tendency for variation in charging to occur. The ignition loss is preferably 1.5 to 17% by weight, more preferably 4 to 10% by weight.

  If the loss on ignition with an average particle size of 20 nm to 200 nm is less than 1.5% by weight, the transfer margin for reverse transfer and hollow out tends to be narrow. If it exceeds 25% by weight, the surface treatment becomes uneven, and there is a tendency for variation in charging to occur. The ignition loss is preferably 2.5 to 20% by weight, more preferably 5 to 15% by weight.

The external additive having an average particle diameter of 6 nm to 20 nm and an ignition loss of 0.5 to 20% by weight is 0.5 to 2 parts by weight with respect to 100 parts by weight of the toner base particles, and the average particle diameter is 20 nm to 0.5 to 3.5 parts by weight of an external additive having 100 nm and an ignition loss of 1.5 to 25% by weight based on 100 parts by weight of the toner base particles, an average particle diameter of 100 to 200 nm, and an ignition loss of 0 A configuration in which at least 0.5 to 2.5 parts by weight of the external additive of 1 to 10% by weight is added to 100 parts by weight of the toner base particles is also preferable. The structure of the external additive with the function of specifying the average particle size and loss on ignition improves the charge imparting property, charge retention, reverse transfer during transfer, and improvement of voids. Effective for removal.
Further, an external additive having a positive charging property with an average particle diameter of 6 nm to 200 nm and an ignition loss of 0.5 to 25% by weight is further added to 0.2 to 1.5 parts by weight based on 100 parts by weight of the toner base particles. It is also preferable to perform the external addition treatment.

The effect of adding an external additive having a positive charging property can prevent the toner from being overcharged during long-term continuous use, thereby further extending the developer life. Furthermore, the effect of suppressing scattering during transfer due to overcharging can also be obtained. In addition, spent on the carrier can be prevented. If the amount is less than 0.2 parts by weight, it is difficult to obtain the effect. If it exceeds 1.5 parts by weight, fogging during development increases. The ignition loss is preferably 1.5 to 20% by weight, more preferably 5 to 19% by weight.
The average particle diameter is a value obtained by taking an enlarged photograph with an SEM (scanning electron microscope) and obtaining an average value of major and minor axes of about 100 particles.
For loss on drying (% by weight), about 1 g of a sample is placed in a container that has been dried, allowed to cool, and precisely weighed in advance and weighed accurately. Dry in a hot air dryer (105 ° C ± 1 ° C) for 2 hours. After cooling in a desiccator for 30 minutes, the weight is precisely weighed and calculated from the following formula.

  Loss on drying (% by weight) = [Loss on drying (g) / Amount of sample (g)] × 100.

  For ignition loss, about 1 g of a sample is placed in a magnetic crucible that has been dried, allowed to cool, and precisely weighed in advance, and weighed accurately. Ignite for 2 hours in an electric furnace set to 500 ° C. After standing to cool in a desiccator for 1 hour, its weight is precisely weighed and calculated from the following formula.

  Loss on ignition (% by weight) = [Loss on ignition (g) / Sample amount (g)] × 100.

  Further, the moisture absorption amount of the treated external additive is preferably 1% by weight or less. Preferably it is 0.5 weight% or less, More preferably, it is 0.1 weight% or less, More preferably, it is 0.05 weight% or less. When the amount is more than 1% by weight, the chargeability is lowered, and filming on the photoconductor during durability is caused. The water adsorption amount was measured with a continuous vapor adsorption device (BELSORP18: Nippon Bell Co., Ltd.) for the water adsorption device.

  The degree of hydrophobicity is determined by methanol titration, weighing 0.2 g of the product to be tested in 50 ml of distilled water charged in a 250 ml beaker. At the tip, methanol is dropped from a burette that is invaded in the liquid until the total amount of the external additive is wet. At that time, slowly stir slowly with an electromagnetic stirrer. The degree of hydrophobicity is calculated by the following equation from the amount of methanol a (ml) essential for complete wetting.

Hydrophobicity = (a / (50 + a)) × 100 (%).
(8) Toner powder physical properties In this embodiment, the toner base particles containing the binder resin, pigment and wax have a volume average particle size of 3 to 6 μm, a volume-based variation coefficient of 10 to 25%, and a number-based distribution. The content of toner particles having a particle size of 2.0 to 3.63 μm is 10 to 85% by number, and toner particles having a particle size of 3.5 to 4.53 μm in a volume-based distribution are 25 to 75% by volume, Toner particles having a particle size of 6.06 μm or more in the volume-based distribution are contained in an amount of 5% by volume or less, and volume percentage of toner particles having a particle size of 3.5 to 4.53 μm in the volume-based distribution is V34. When the number% of toner particles having a particle diameter of 3.5 to 4.53 μm in the number standard distribution is P34, P34 / V34 is preferably in the range of 0.4 to 2.2.
Preferably, the toner base particles have a volume average particle size of 3 to 5 μm, a volume-based variation coefficient of 10 to 20%, and a content of toner particles having a particle size of 2.0 to 3.63 μm in a number-based distribution is 15 ~ 85% by number, toner particles having a particle size of 3.5 to 4.53 μm in a volume-based distribution are 30 to 65% by volume, toner particles having a particle size of 6.06 μm or more in a volume-based distribution are 2 volumes % Or less, and P34 / V34 is preferably in the range of 0.5 to 1.5.
More preferably, the toner base particles have a volume average particle size of 3 to 5 μm, a volume-based variation coefficient of 10 to 16%, and a content of toner particles having a particle size of 2.0 to 3.63 μm in a number-based distribution. 25 to 85% by number, toner particles having a particle size of 3.5 to 4.53 μm in the volume-based distribution are 40 to 60% by volume, toner particles having a particle size of 6.06 μm or more in the volume-based distribution are It is preferably contained at 0.5% by volume or less, and P34 / V34 is preferably in the range of 0.5 to 0.9.

  In a high resolution image quality, and further in a tandem configuration, it is possible to prevent reverse transfer during transfer and prevent voids and achieve both oil-less fixing. The toner particle size distribution affects toner fluidity, image quality, storage stability, filming on a photoreceptor, a developing roller, and a transfer body, aging characteristics, transferability, and in particular, multi-layer transfer in a tandem system. In addition, it affects the high temperature non-offset property and glossiness in oilless fixing. In a toner containing a wax for realizing oil-less fixing, the amount of fine powder affects the compatibility with tandem transferability.

When the volume average particle size exceeds 6 μm, it is impossible to achieve both image quality and transfer. When the volume average particle size is less than 3 μm, it tends to be difficult to convey toner particles during development.
When the content of toner particles having a particle size of 2.0 to 3.63 μm in the number-based distribution is less than 10% by number, it tends to be impossible to achieve both image quality and transfer. When it exceeds 85% by number, it tends to be difficult to convey the toner during development. Further, filming on the photosensitive member, the developing roller, and the transfer member may occur. Furthermore, fine powder tends to be offset at high temperature because of its high adhesion to the heat roller. In the tandem system, toner aggregation tends to be strong, and a transfer failure of the second color tends to occur during multilayer transfer. An appropriate range is required.
When toner particles having a particle size of 3.5 to 4.53 μm in the volume-based distribution are less than 25% by volume, the image quality tends to deteriorate. If it exceeds 75% by volume, it tends to be impossible to achieve both image quality and transfer.
If toner particles having a particle size of 6.06 μm or more in the volume-based distribution are contained in excess of 5% by volume, the image quality is deteriorated and tends to cause transfer defects.
When P34 / V34 is less than 0.4, the amount of fine powder present becomes excessive, and the fluidity, transferability, and background fog tend to deteriorate. When it is larger than 2.2, there are many large particles and the particle size distribution becomes broad, and the image quality tends not to be improved.
The purpose of defining P34 / V34 can be used as an index for making toner particles small and narrowing the particle size distribution.

  The coefficient of variation is the standard deviation of the toner particle size divided by the average particle size. This is based on the particle diameter measured using a Coulter counter (Coulter). The standard deviation is expressed as the square root of the value obtained by dividing the square of the difference from the average value of each measured value when (n-1) is measured when n particle systems are measured.

That is, the coefficient of variation represents the extent of the particle size distribution, and if the coefficient of variation of the volume particle size distribution is less than 10%, or the coefficient of variation of the number particle size distribution is less than 10%, it is difficult to produce, This will increase costs. When the coefficient of variation in volume particle size distribution is greater than 25% or the coefficient of variation in number particle size distribution is greater than 28%, the particle size distribution becomes broad and toner cohesion becomes stronger, and filming and transfer to a photoconductor. It tends to cause defects.
Further, the shape index of the toner is preferably 1.25 to 1.55, more preferably 1.33 to 1.46, and still more preferably 1.35 to 1.42. When the shape index of the toner is smaller than 1.25 and the sphere progresses too much, the cleaning performance by the rubber blade is deteriorated. On the other hand, when the shape index of the toner is larger than 1.55 and the irregular shape proceeds too much. It tends to be a decrease in transferability.
Further, when the shape index of the toner base particles is SC and the volume average particle diameter is d50 (μm), the product of SC and d50 (SC × d50) is preferably 3.9 to 7.3. Preferably it is 4.0-6.6, More preferably, it is 4.1-5.7.

  By prescribing this numerical value, the cleaning performance with the rubber blade tends to deteriorate when the spheroidization of the shape proceeds when the particle shifts to a small particle size. In addition, when the particles shift to a large particle size, if the shape progresses to an irregular shape, there is a tendency to deteriorate transferability and image quality. In the case of a small particle size, the shape is shifted to an irregular shape. In order to maintain the cleaning property and to maintain the image quality by shifting the shape to a spherical shape in the case of a large particle size particle, the product of SC and d50 is set within a certain range. If it is smaller than 3.9, the cleaning property tends to deteriorate. If it is larger than 7.3, the image quality tends to deteriorate.

The particle size distribution is measured by using a Coulter Counter TA-II type (Coulter Counter Co., Ltd.) and connecting an interface (manufactured by Nikkaki Co., Ltd.) for outputting the number distribution and volume distribution and a personal computer. The electrolyte solution is a surfactant (sodium lauryl sulfate) added to a concentration of 1% by weight. About 2 mg of the toner to be measured is added to about 50 ml, and the electrolyte solution in which the sample is suspended is dispersed by an ultrasonic disperser for about 3 minutes. Processing was performed, and an aperture of 70 μm was used with a Coulter counter TA-II type. In the 70 μm aperture system, the particle size distribution measurement range is 1.26 μm to 50.8 μm, but the region less than 2.0 μm is not practical because the measurement accuracy and measurement reproducibility are low due to the influence of external noise and the like. Therefore, the measurement area was set to 2.0 μm to 50.8 μm.
The shape index was obtained by the following formula using a real surface view microscope (VE7800) manufactured by Keyence Corporation, taking about 100 toner base particles magnified 1000 times, measuring the maximum length and the projected area (d : Maximum length of toner particles, A: projected area of toner particles).
SC (shape factor) = π · d ² / (4 · A)
(9) Oilless Color Fixation In this embodiment, the present invention is suitably used for an electrophotographic apparatus having a fixing process having an oilless fixing configuration in which oil is not used as a toner fixing unit. As the heating means, electromagnetic induction heating is a preferable configuration from the viewpoint of shortening the warm-up time and saving energy. A heating and pressurizing unit having at least a magnetic field generating unit, a rotary heating member having at least a heat generation layer and a release layer generated by electromagnetic induction, and a rotary pressurizing member forming a fixed nip with the rotary heating member; In this configuration, a transfer medium such as copy paper on which toner is transferred is passed between the rotary heating member and the rotary pressure member, and is fixed. As a feature thereof, the warm-up time of the rotary heating member is very fast compared to the case where a conventional halogen lamp is used. For this reason, since the copying operation is started in a state where the temperature of the rotary pressure member is not sufficiently raised, low temperature fixing and a wide range of offset resistance are required.

  As a configuration, a configuration using a fixing belt in which a heating member and a fixing member are separated is also preferably used. As the belt, a heat resistant belt such as a nickel electroformed belt or a polyimide belt having heat resistance and deformability is preferably used. In order to improve releasability, it is preferable to use silicone rubber, fluororubber, or fluororesin as the surface layer.

  In such fixing, conventionally, release oil has been applied to prevent offset. If the toner has releasability without using oil, it is not necessary to apply release oil. Therefore, by using the toner of this embodiment, low-temperature fixing and a wide range of offset resistance can be realized without using oil, and high color translucency can be obtained. Further, the toner can be prevented from being overcharged, and toner flying due to the charging action with the heating member or the fixing member can be suppressed.

(Example of carrier production)
39.7Mol% in terms of MnO, 9.9 mol% in terms of MgO, in 0.8 mol% wet ball mill 49.6Mol% and SrO terms in terms _{of Fe} 2 _{O 3,} and ground for 10 hours after mixing was dried, It was kept at 950 ° C. for 4 hours and pre-baked. This was pulverized with a wet ball mill for 24 hours, then granulated with a spray dryer, dried, and held in an electric furnace at 1270 ° C. for 6 hours in an atmosphere with an oxygen concentration of 2%, followed by firing. Then, it was crushed and further classified to obtain a ferrite particle core material having an average particle diameter of 50 μm and a saturation magnetization of 65 emu / g when the applied magnetic field was 3000 oersted.

Next, R ₁ and R ₂ represented by (Chemical Formula ₂ ) are methyl groups, that is, (CH ₃ ) ₂ SiO _2/2 units are 15.4 mol%, and R ₃ represented by (Chemical Formula 3) is a methyl group, that is, 250 g of polyorganosiloxane having a CH ₃ SiO _3/2 unit of 84.6 mol% and CF ₃ CH ₂ CH ₂ Si (OCH ₃ ) ₃ 21 g were reacted to obtain a fluorine-modified silicone resin. Further, 100 g of the fluorine-modified silicone resin in terms of solid content and 10 g of aminosilane coupling agent (γ-aminopropyltriethoxysilane) were weighed and dissolved in 300 cc of toluene solvent.

Coating was performed on 10 kg of the ferrite particles by stirring the coating resin solution for 20 minutes using an immersion drying type coating apparatus. Thereafter, baking was performed at 260 ° C. for 1 hour to obtain carrier CA1.
(2) Preparation of resin particle dispersion Next, examples of the toner of the present invention will be described, but the present invention is not limited to these examples.
(Table 1) shows the characteristics of the resin particles obtained in the prepared resin particle dispersions (RL1 to RL3, RH1 to 6).
“Mn” is the number average molecular weight, “Mw” is the weight average molecular weight, “Mz” is the Z average molecular weight, and “Mw / Mn” is the ratio Mw / Mn of the weight average molecular weight (Mw) to the number average molecular weight (Mn). , “Mz / Mn” is the ratio Mz / Mn of the Z average molecular weight (Mz) to the number average molecular weight (Mn), “Mp” is the peak value of molecular weight, Tg (° C.) is the glass transition point, and Ts (° C.) is softened. Represents a point.

(a) Preparation of resin particle dispersion RL1 A monomer liquid consisting of 240.1 g of styrene, 59.9 g of n-butyl acrylate, and 8 g of acrylic acid was added to 440 g of ion-exchanged water (Sanyo). Kasei Co., Ltd .: Nonipol 400) 7.2 g, anionic surfactant (Daiichi Kogyo Seiyaku, Neogen S20-F (20 wt% aqueous solution concentration)) 24 g (substantial anion amount 4.8 g), dodecanethiol 8 g were used. Then, 4.5 g of potassium persulfate was added thereto, and emulsion polymerization was performed at 78 ° C. for 3 hours. Thereafter, aging treatment was further performed at 90 ° C. for 4 hours to prepare a resin particle dispersion RL1 in which resin particles were dispersed. The pH of the resin dispersion at this time was 1.8.
Table 2 shows the nonionic amount (g), the anionic amount (g), and the ratio of the nonionic amount (% by weight) to the total amount of the surfactant used in each resin particle dispersion. In the liquid using an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen S20-F (solid content 20% by weight concentration)), the weight ratio in Table 2 represents the actual anion amount ratio.
(Table 3) and (Table 4) show the blending amounts of acrylic acid, potassium persulfate, etc. used in each resin particle dispersion based on the preparation of resin particle dispersion RL1 in the emulsion polymerization of each resin particle dispersion. Show. Potassium persulfate indicates parts by weight based on 100 parts by weight of the monomer component.

(3) Preparation of pigment dispersion
(a) Preparation of pigment particle dispersion CPM1 In a 1 L beaker, weigh 300 g of ion-exchanged water, 16 g of nonionic dispersant A (SN1) and 4 g of anionic dispersant B (SA1), and solidify the surfactant with a magnetic stirrer. Stir until the minutes are dissolved. 80 g of pigment MQ1 was added to this aqueous surfactant solution, and the mixture was further stirred with a magnetic stirrer for 10 minutes.
Next, FIG. 3 shows a schematic view of a stirring and dispersing apparatus (TK film mix manufactured by Tokushu Kika Co., Ltd.), and FIG. 4 shows a view from above. Reference numeral 801 denotes an outer tank, in which cooling water is injected from 808 and discharged from 807. Reference numeral 802 denotes a dam plate that stops the liquid to be processed, and a hole is formed in the central portion. Reference numeral 803 denotes a rotating body that rotates at a high speed and is fixed to the shaft 806 and can rotate at a high speed. A hole of about 1 to 5 mm is formed on the side surface of the rotating body, and the liquid to be processed can be moved. The tank is 120 ml, and about half of the liquid to be treated is charged. The speed MAX of the rotating body can be up to 50 m / s. The diameter of the rotating body is 52 mm, and the inner diameter of the tank is 56 mm. Reference numeral 44 denotes a raw material inlet for continuous processing. Sealed for high-pressure processing or batch processing.

The above-described pigment MQ1 was added and ion-exchanged water in which the dispersant was dissolved was charged. CPM2, CPM3, CPC1, CPY1, and CPB1 were prototyped based on the adjustment conditions of CPM2.
(b) Preparation of Pigment Particle Dispersion CPM6 FIG. 5 is a schematic view of a stirring and dispersing apparatus, and FIG. 6 is a top view. Reference numeral 850 denotes a raw material inlet, and reference numeral 852 denotes a fixed body having a floating structure. A narrow gap of about 1 μm to 10 μm is formed by the pressing force of the rotating body 853 and the pushing force of the rotating body 853. Reference numeral 854 denotes a shaft connected to a motor (not shown). The raw material charged from 850 receives a strong shearing force between the gap between the stationary body and the rotating body and is dispersed into fine particles in the liquid. The processed raw material liquid is discharged from 856. FIG. 6 shows a view from above. The discharged raw material liquid 855 is blown radially and collected in a sealed container. The outer diameter of the rotating body is 100 mm.
In a 1 L beaker, 300 g of ion-exchange water, 20 g of nonionic dispersant A (SN2) and 4 g of anionic dispersant B (SA2) were weighed and stirred with a magnetic stirrer until the solid content of the surfactant was dissolved. 80 g of the pigment MN1 was added to this aqueous surfactant solution and stirred with a magnetic stirrer for 10 minutes. The pre-dispersed liquid is charged from the charging port 80 and instantly refined. The supply amount was 1 kg / h, and the rotating body was rotated at a maximum speed of 100 m / s. CPM7 and CPM8 were prototyped based on the adjustment conditions of CPM6.
(c) Preparation of pigment particle dispersion cpm4 308 g of ion-exchanged water, 4.8 g of nonionic dispersant A (SN1) and 6.4 g of anionic dispersant B (SA1) were weighed into a 1 L beaker and interfaced with a magnetic stirrer. Stir until the solids of the activator are dissolved. 80 g of pigment MQ1 was added to this aqueous dispersant solution and stirred with a magnetic stirrer for 10 minutes. Next, the contents were transferred to a 1 L tall beaker and dispersed using a homogenizer (manufactured by IKA, T-25) at a rotational speed of 8500 rpm for 5 minutes. cpm5, cpm9 and cpm10 were made on the basis of the adjustment conditions of cpm4.
The pigments used in (Table 5), the nonionic dispersant A in (Table 6), and the anionic dispersant B in (Table 7) are shown.

Table 8 shows the pigment used in each pigment dispersion, the dispersant used, and the conditions of the pigment dispersion. The numbers in parentheses are the parts by weight of the dispersant or surfactant based on 100 parts by weight of the pigment particles.

In (Table 9), ion-exchanged water, pigment weight (g), dispersant amount (g), pigment concentration (wt%), etc. used in the production of the dispersion were generated in (Table 10) and (Table 11). PQ16, PQ50, PQ84, PN16, PN50, and PN84 measured with a Horiba laser diffraction particle size measuring instrument (LA920) of each pigment dispersion are shown.

(4) Preparation of wax dispersion
(a) Preparation of Wax Particle Dispersion WA11 FIG. 3 is a schematic view of a stirring and dispersing device (TK Film Mix manufactured by Tokushu Kika Co., Ltd.), and FIG. Reference numeral 801 denotes an outer tank, in which cooling water is injected from 808 and discharged from 807. Reference numeral 802 denotes a dam plate that stops the liquid to be processed, and a hole is formed in the central portion. Reference numeral 803 denotes a rotating body that rotates at a high speed and is fixed to the shaft 806 and can rotate at a high speed. A hole of about 1 to 5 mm is formed on the side surface of the rotating body, and the liquid to be processed can be moved. The tank is 1 L, and about half of the liquid to be treated is charged. The speed MAX of the rotating body can be up to 50 m / s.
The diameter of the rotating body is 52 mm, and the inner diameter of the tank is 56 mm. Reference numeral 804 denotes a raw material inlet for continuous processing. Sealed for high-pressure processing or batch processing.

In a tank at normal pressure, 90 g of wax (W1) and 90 g of wax (W11) were charged into 394 g of ion-exchanged water in which 27 g of dispersant B (EP1) of polypropylene glycol ethylene oxide adduct was dissolved. Was 30 min / s for 5 min, and then the rotational speed was increased to 50 m / s for 2 min. A wax particle dispersion WA11 was formed.
Table 12 shows the polymer dispersants used in the preparation of the wax particle dispersion, the glass transition point (Tg), the softening point (Tm), the weight average molecular weight, and the acid value. In Table 13, the weight average molecular weight of the surfactant of the polypropylene glycol ethylene oxide adduct and its hydrophobic group, and EO (wt%) indicate the weight% of ethylene oxide relative to the polypropylene glycol ethylene oxide adduct.

(Table 14) and (Table 15) show the wax materials and their properties used in the preparation of the wax particle dispersion, respectively.

Based on the adjustment conditions of the wax particle dispersion WA11 in (Table 16) and (Table 17), the wax composition used for each wax particle dispersion wax particle dispersion (WA11-WA15), the dispersant used, and the blending weight thereof Parts and weight (g) are shown. “First wax” and “second wax” indicate the wax material charged in the wax particle dispersion, and the value in parentheses at the end of the symbol indicating the wax indicates the blending weight ratio (weight ratio) of the wax. Represent. The numbers in parentheses of Dispersant C and Dispersant D are the weight parts of the surfactant based on 100 parts by weight of the wax particles.

(5) Preparation of toner base
(a) Preparation of toner base B1 (STD)
204 g of core resin particle dispersion (RL1), 30 g of pigment particle dispersion (CPM1), and pigment particle dispersion (CPM6) are placed in a cylindrical 2 L glass container equipped with a thermometer, cooling pipe, pH meter, and stirring blade. 25 g and 80 g of wax particle dispersion WA11 were added, 480 ml of ion-exchanged water was added, and the mixture was mixed for 10 min using a homogenizer (manufactured by IKA: Ultra Turrax T25) to prepare a mixed particle dispersion.
Thereafter, 1N NaOH was added to the obtained mixed dispersion to adjust the pH to 11.5, and then 280 g of a 23 wt% magnesium sulfate aqueous solution was added and stirred for 10 min. Thereafter, the temperature was raised from 20 ° C. to 90 ° C. at a rate of 1 ° C./min, followed by heat treatment for 1.5 hours to obtain core particles. The obtained core particle dispersion had a pH of 9.1. The pH of the core particle dispersion was adjusted to 6 and heated for 1 hour.
Thereafter, 110 g of a shell resin particle dispersion RH4 having a pH adjusted to 8 was added in a state where the water temperature was 92 ° C., and heat treatment was performed for 3.5 hours after completion of the dropping to obtain particles in which shell resin particles were fused. .
Then, after cooling, the reaction product (toner base) was filtered, washed with ion exchange water, and then the obtained toner base was dried at 40 ° C. for 6 hours by a fluid dryer.
The toner bases B1 to B10 were experimentally evaluated by changing the core resin particle dispersion, the pigment particle dispersion, the shell resin particle dispersion, and the like based on the conditions of B1. Table 18 shows the composition of each toner matrix prepared as an example of toner matrix preparation.

Table 19 shows the characteristics obtained with the toner base prepared. d50 (μm) represents the volume average particle diameter and volume variation coefficient of the toner base particles.

In the process of agglomerating and fusing resin particles, pigment particles, and wax particles to produce core particles, it is confirmed whether pigment particles and wax particles are surrounded by resin particles and taken into the core particles. It can be determined by taking out the reaction solution during the fusion reaction at regular intervals and centrifuging it. If pigment particles and wax particles are taken into the core particles, the reaction solution is separated into two layers of solid and liquid when centrifuged, and the supernatant becomes colorless and transparent. When the wax particles are not taken into the core particles, the supernatant liquid becomes cloudy. When the pigment particles are not taken into the core particles, the supernatant liquid shows the hue of the pigment.
For the coagulation property of the core particles, the dispersion sampled during the core particle aggregation reaction was diluted with an equal amount of ion-exchanged water, placed in a test tube, and placed in a centrifuge for 5 minutes at 3000 min- ¹ . It shows a state in which the turbidity of the centrifuged supernatant is visually determined.
In B1 to B5 and B8 to B10, the supernatant liquid becomes transparent in 1.5 hours (h) to 3 hours (h), and particles having a small particle size and a narrow particle size distribution are obtained. 12 and 13 show SEM images of the core particles of B1 and B2. The core particles are not in a state where the pigment particles are left behind, and the surfaces thereof are uniform and smooth.
In B6 and B7, the aggregation of the pigment did not proceed even in the aggregation reaction for 7 hours, and the supernatant liquid remained magenta. 14 and 15 show SEM images of B6 and B7 core particles. Pigment particles that are not aggregated in the core particles remain on the surface, and the surface of the core particles is uneven and poor in smoothness, resulting in poor particle formation. It seems to be due to the non-uniform effect of the cohesiveness of the pigment particles.
(6) External additives Next, examples of external additives will be described. (Table 20) shows each material and its characteristic about the external additive (S1-S4) used by the present Example.

In the case of processing with a plurality of types of the processing material 1 and the processing material 2, the blending weight ratio of each processing material is shown in (). “5-minute value” and “30-minute value” represent the charge amount ([μC / g]), which were measured by the blow-off method of frictional charge with an uncoated ferrite carrier. Specifically, in an environment of 25 ° C. and 45 RH%, 50 g of carrier and 0.1 g such as silica are mixed in a 100 ml polyethylene container, and stirred for 5 minutes and 30 minutes at a speed of 100 min ⁻¹ by longitudinal rotation. 0.3 g was collected and measured by blowing with nitrogen gas at 1.96 × 10 ⁴ [Pa] for 1 minute.

For negative chargeability, the 5-minute value is preferably −100 to −800 μC / g, and the 30-minute value is preferably −50 to −600 μC / g. A high charge amount of silica can exhibit such characteristics with a small amount of addition.
(7) Toner Composition and External Addition Processing Next, a toner composition and an example of external addition processing will be described. Table 21 shows the material composition of the toner according to the present invention prepared as a toner preparation example. In the external additive column, the value in parentheses at the end of the symbol indicating the external additive represents the blending amount (part by weight) of the external additive with respect to 100 parts by weight of the toner base. In the external addition process (Henschel mixer FM20B, manufactured by Mitsui Mining Co., Ltd.), stirring blade Z0S0 type, rotation speed 2000 min ⁻¹ , treatment time 5 min, and input amount 1 kg were performed.

  FIG. 1 is a cross-sectional view showing a configuration of an image forming apparatus for forming a full-color image used in this embodiment. In FIG. 1, the outer casing of the color electrophotographic printer is omitted. The transfer belt unit 17 includes a transfer belt 12, a first color (yellow) transfer roller 10Y made of an elastic body, a second color (magenta) transfer roller 10M, a third color (cyan) transfer roller 10C, and a fourth color (black). Transfer roller 10K, drive roller 11 made of aluminum roller, second transfer roller 14 made of elastic body, second transfer driven roller 13, belt cleaner blade 16 for cleaning the toner image remaining on the transfer belt 12, and opposed to the cleaner blade A roller 15 is provided at a position to be used. At this time, the distance from the first color (Y) transfer position to the second color (M) transfer position is 70 mm (second color (M) transfer position to third color (C) transfer position, third color (C). The fourth color (K) transfer position is the same distance from the transfer position), and the peripheral speed of the photosensitive member is 125 mm / s.

The transfer belt 12 is used by kneading a conductive filler in an insulating polycarbonate resin and forming a film with an extruder. In the present example, a film obtained by adding 5 parts by weight of conductive carbon (for example, ketjen black) to 95 parts by weight of polycarbonate resin (for example, Iupilon Z300, manufactured by Mitsubishi Gas Chemical) as the insulating resin was used. Further, the surface is coated with a fluororesin, the thickness is about 100 μm, the volume resistance is 10 ⁷ to 10 ¹² Ω · cm, and the surface resistance is 10 ⁷ to 10 ¹² Ω / □. This is also for improving dot reproducibility. This is to effectively prevent slack and charge accumulation due to long-term use of the transfer belt 12, and the coating of the surface with a fluororesin is effective for toner filming on the surface of the transfer belt after long-term use. This is to prevent it. If the volume resistance is less than 10 ⁷ Ω · cm, retransfer is likely to occur, whereas if it is greater than 10 ¹² Ω · cm, the transfer efficiency deteriorates.

The first transfer roller is a carbon conductive urethane foam roller having an outer diameter of 8 mm, and the resistance value is 10 ² to 10 ⁶ Ω. During the first transfer operation, the first transfer roller 10 is pressed against the photoreceptor 1 with a pressing force of 1.0 to 9.8 (N) via the transfer belt 12, and the toner on the photoreceptor is transferred onto the belt. Is done. If the resistance value is smaller than 10 ² Ω, retransfer is likely to occur. If it exceeds 10 ⁶ Ω, transfer defects are likely to occur. If it is less than 1.0 (N), transfer defects occur, and if it is greater than 9.8 (N), transfer character omission occurs.

The second transfer roller 14 with carbon conductive urethane foam roller having an outer diameter of 10 mm, the resistance value is ¹⁰ 2 to 10 ⁶ Omega. The second transfer roller 14 is pressed against the transfer roller 13 via the transfer belt 12 and a transfer medium 19 such as paper or OHP. The transfer roller 13 is configured to be driven to rotate by the transfer belt 12. In the second transfer, the second transfer roller 14 and the counter transfer roller 13 are pressed against each other with a pressing force of 5.0 to 21.8 (N), and the toner is transferred from the transfer belt onto the recording material 19 such as paper. The If the resistance value is smaller than 10 ² Ω, retransfer is likely to occur. Larger transfer defects are more likely to occur than 10 ⁶ Ω. If it is smaller than 5.0 (N), transfer failure occurs. If it is larger than 21.8 (N), the load increases and jitter tends to occur.

  Four sets of image forming units 18Y, 18M, 18C, and 18K for each color of yellow (Y), magenta (M), cyan (C), and black (K) are arranged in series as shown in the figure.

  Each of the image forming units 18Y, 18M, 18C, and 18K is composed of the same constituent members except for the developer contained therein, so that the Y image forming unit 18Y will be described to simplify the description, and the units for other colors The description of is omitted.

  The image forming unit is configured as follows. 1 is a photosensitive member, 3 is a pixel laser signal light, 4 is a developing roller having an outer diameter of 10 mm made of aluminum having a magnet having a magnetic force of 1200 gauss, and is opposed to the photosensitive member with a gap of 0.3 mm. Rotate in the direction of. 6 is a stirring roller that stirs the toner and carrier in the developing device and supplies them to the developing roller. The composition ratio of the carrier and the toner is read by a magnetic permeability sensor (not shown) and is supplied from a toner hopper (not shown) in a timely manner. A metal magnetic blade 5 regulates the magnetic brush layer of the developer on the developing roller. The developer amount is 150 g. The gap was 0.4 mm. Although the power supply is omitted, a DC voltage of −500 V and an AC voltage of 1.5 kV (pp) and a frequency of 6 kHz are applied to the developing roller 4. The peripheral speed ratio between the photoreceptor and the developing roller was 1: 1.6. The mixing ratio of toner and carrier was 93: 7, and the developer amount in the developing unit was 150 g.

  A charging roller 2 having an outer diameter of 10 mm made of epichlorohydrin rubber is applied with a DC bias of -1.2 kV. The surface of the photoreceptor 1 is charged to −600V. 8 is a cleaner, 9 is a waste toner box, and 7 is a developer.

  The paper is transported from below the transfer unit 17 so that the paper 19 is fed by a paper feed roller (not shown) to the nip portion where the transfer belt 12 and the second transfer roller 14 are pressed. A conveyance path is formed.

  The toner on the transfer belt 12 is transferred to the paper 19 by +1000 V applied to the second transfer roller 14, and includes a fixing roller 201, a pressure roller 202, a fixing belt 203, a heating medium roller 204, and an induction heater unit 205. It is conveyed to the fixing unit and fixed there.

  FIG. 2 shows the fixing process. A belt 203 is placed between the fixing roller 201 and the heat roller 204. A predetermined load is applied between the fixing roller 201 and the pressure roller 202, and a nip is formed between the belt 203 and the pressure roller 202. An induction heater unit 205 including a ferrite core 206 and a coil 207 is provided on the outer peripheral surface of the heat roller 204, and a temperature sensor 208 is provided on the outer surface.

  The belt has a structure in which 30 μm of Ni is used as a base, silicone rubber is 150 μm thereon, and further, PFA tube is 30 μm.

  The pressure roller 202 is pressed against the fixing roller 201 by a pressure spring 209. The recording material 19 having the toner 210 moves along the guide plate 211.

  The fixing roller 201 as a fixing member is made of silicon rubber having a rubber hardness (JIS-A) of 20 degrees according to JIS standard on the surface of an aluminum hollow roller core metal 213 having a length of 250 mm, an outer diameter of 14 mm, and a thickness of 1 mm. An elastic layer 214 having a thickness of 3 mm is provided. A silicone rubber layer 215 is formed thereon with a thickness of 3 mm and has an outer diameter of about 26 mm. It receives a driving force from a driving motor (not shown) and rotates at 125 mm / s.

  The heat roller 204 is a hollow pipe having a thickness of 1 mm and an outer diameter of 20 mm. The surface temperature of the fixing belt was controlled to 170 ° using a thermistor.

  The pressure roller 202 as a pressure member has a length of 250 mm and an outer diameter of 20 mm. This is provided with a 2 mm thick elastic layer 217 made of silicone rubber having a rubber hardness (JIS-A) of 55 degrees according to JIS standard on the surface of a hollow roller core metal 216 made of aluminum having an outer diameter of 16 mm and a thickness of 1 mm. The pressure roller 202 is rotatably installed, and a nip width of 5.0 mm is formed between the pressure roller 202 and the fixing roller 201 by a spring-loaded spring 209 on one side 147N.

  The operation will be described below. In the full color mode, all of the first transfer rollers 10 of Y, M, C, and K are pushed up and press the photoreceptor 1 of the image forming unit via the transfer belt 12. At this time, a DC bias of +800 V is applied to the first transfer roller. An image signal is sent from the laser beam 3 and is incident on the photoreceptor 1 whose surface is charged by the charging roller 2 to form an electrostatic latent image. The toner on the developing roller 4 that rotates in contact with the photoreceptor 1 visualizes the electrostatic latent image formed on the photoreceptor 1.

  At this time, the image forming speed of the image forming unit 18Y (125 mm / s equal to the peripheral speed of the photoconductor) and the moving speed of the transfer belt 12 are 0.5 to 1.5% slower than the transfer belt speed. Is set to

  In the image forming process, the Y signal light 3Y is input to the image forming unit 18Y, and image formation with Y toner is performed. Simultaneously with the image formation, the first transfer roller 10Y causes the Y toner image to be transferred from the photoreceptor 1Y to the transfer belt 12. At this time, a DC voltage of +800 V was applied to the first transfer roller 10Y.

  With a time lag between the first color (Y) first transfer and the second color (M) first transfer, M signal light 3M is input to the image forming unit 18M, and image formation with M toner is performed. Simultaneously with the image formation, the M toner image is transferred from the photosensitive member 1M to the transfer belt 12 by the action of the first transfer roller 10M. At this time, the first color (Y) toner is formed and the M toner is transferred. Similarly, image formation with C (cyan) and K (black) toners is performed, and simultaneously with image formation, a YMCK toner image is formed on the transfer belt 12 by the action of the first transfer rollers 10C and 10K. This is a so-called tandem method.

On the transfer belt 12, toner images of four colors are positioned and overlapped to form a color image. After the transfer of the last K toner image, the four color toner images are collectively transferred to the paper 19 fed from a paper feed cassette (not shown) at the same time by the action of the second transfer roller 14. At this time, the transfer roller 13 was grounded, and a DC voltage of +1 kV was applied to the second transfer roller 14. The toner image transferred to the paper was fixed by a pair of fixing rollers 201 and 202. The paper was then discharged out of the apparatus through a pair of discharge rollers (not shown). The residual transfer toner remaining on the intermediate transfer belt 12 was cleaned by the action of the cleaning blade 16 to prepare for the next image formation.
(Example of image evaluation)
Next, an example of image output evaluation for toner and two-component developer will be described. Here, an image forming apparatus is used, and several kinds of two-component developers with different mixing ratios of toner and carrier are subjected to a running durability test of 100,000 sheets each with A4 plate output to determine the charge amount and the image density. In addition to the measurement, the ground fog in the non-image area in the output sample, the uniformity in the entire solid image, the transferability (character skipping during transfer, reverse transfer, transfer omission), and toner filming were evaluated. Image density (ID) evaluation measured the black solid part using the reflection densitometer RD-914 made from Macbeth Division of Kollmorgen Instruments Corporate.

The charge amount was measured by the blow-off method of frictional charging with the ferrite carrier. Specifically, 25 ° C., under an environment with a relative humidity of 45% RH, a sample of the durability evaluation was 0.3g collected was measured by blowing for 1 minute in a nitrogen gas 1.96 × ¹⁰ 4 Pa.
(Table 22) shows, for each of the two-component developers (DB1 to DB10) used in this example, a configuration of toner and carrier as the two-component developer, and 100,000 sheets running durability test with A4 size paper. Results of implementation and evaluation are shown.

When the fog level is 0.01 or less, the fog level is a better level “A”, and when the fog level is 0.01 or less and 0.03 or less, the fog level is slightly increased “B”. If it is greater than 03, it indicates a problematic level “C”.
As for the uniformity of the entire solid image, when a solid image sample is taken on the entire surface in A4 size, if the image density partially changes and the image density difference is small, the comparison between “A” and “A”. If the image density difference is a level that can be seen a little, "B" is indicated, and if the image density difference is partially noticeable, it is indicated by "C".
For character skipping at the time of transfer, when the characters “轟, 議, 魏” are printed, evaluation is performed with the state of toner present around the line. If the toner present around the line is low and the level is “ “A” is indicated by “B” if the toner level is slightly present around the line, and “C” if the toner level is high near the line.
In reverse transfer, when two or more color image samples are printed, the first color toner is transferred from the photoconductor to the transfer belt, and then the second color toner is transferred from the photoconductor to the transfer belt. A phenomenon in which part of the first color toner adheres to the second color photoconductor. In the evaluation, the toner of the first color adheres to the photoconductor of the second color, is removed from the photoconductor by the craning blade, and the amount of toner collected in the waste toner box is visually evaluated. “A” if the first and second color toners are hardly mixed, “B” if the first and second color toners are slightly mixed, and clearly mixed. For example, “C”.
In the middle of transfer, a pattern “+” where lines intersect is printed, and the presence state of toner is evaluated at this intersection. If the level at which the toner is present at the intersection, “A” is indicated, “B” if the level at which there is no toner at the intersection is “B”, and “C” if no toner is present at the intersection. .
The two-component developers DB1 to DB5 and DB8 to DB10 using the toner according to the present invention were subjected to a 100,000 sheet running durability test on A4 size paper (Panasonic designated paper (104 g / m ² )). Regarding the image density before and after the running test, the image density showed a stable characteristic with little change of 1.35 or more. The toner filming on the photoconductor was at a level where there was no practical problem. In addition, toner filming on the transfer belt was at a level causing no practical problem. Further, no transfer belt cleaning failure occurred. Even in a full-color image in which the three colors overlap, no paper wrapping around the fixing belt occurred.

Further, with respect to the non-image area fogging and the entire surface solid image uniformity, the two-component developer according to the present invention was free from the occurrence of ground fogging in the non-image area, and did not scatter toner, and had high resolution. Further, the uniformity when taking the entire solid image at the time of development was also good. With regard to transferability (character skipping during transfer, reverse transfer, and transfer skipping), skipping and the like were at a level that has no practical problem. In addition, no transfer failure occurred even in a full-color image in which the three colors overlapped. The transfer efficiency was about 95%.
On the other hand, DB6 and DB7 have a wide particle size distribution, which may be affected by particles lacking in uniformity, increase in fog, decrease in transferability, and the like.
Table 23 shows the evaluation results for the fixing property, non-offset property, high-temperature storage stability, and paper wrapping property around the fixing belt. In the table, “A” indicates that the evaluation result is good, thermal aggregation does not occur after standing at high temperature, and the powder state is maintained. “B” indicates that the evaluation level is slightly inferior to that of A, but the aggregation is loosened by a small load of 30 g / cm ² or more. “C” indicates that there is a problem, and after standing at a high temperature, the agglomerates are formed and the agglomerates do not collapse unless a load of 300 g / cm ² or more is applied. Here, coating weight 1.2 mg / cm ² of the solid image process speed 125 mm / s, the oil in the fixing device using the belt which is not coated, in A4 size paper (Panasonic designated paper (104g ^{/ m} 2)) The minimum fixing temperature and the temperature at which the offset phenomenon occurred at a high temperature were measured. Further, in the storage stability test at a high temperature, the state of the toner after being left at 50 ° C. for 24 hours was evaluated. The film transmittance for OHP was measured with a spectrophotometer U-3200 (Hitachi, Ltd.) for the transmittance of 700 nm light.

In the fixability evaluation, TB1 to TB5 and TB8 to 10 showed a low temperature fixability of 140 ° C. or lower and a high temperature non-offset property of 205 ° C. or higher. The high-temperature storage stability was also good. In TB6 and TB7, the low-temperature fixability and the high-temperature non-offset property tend to be lower than those of other toners. It seems that the dispersion state of the pigment particles affects the dispersibility of the wax.

  The present invention is useful not only for an electrophotographic system using a photoconductor but also for a system in which a paper or a toner containing a conductive material is directly deposited on a substrate as a wiring pattern.

Sectional drawing which shows the structure of the image forming apparatus used in the Example of this invention Sectional drawing which shows the structure of the fixing unit used in the Example of this invention Schematic of the stirring and dispersing apparatus used in the examples of the present invention View from above of the stirring and dispersing device used in the examples of the present invention Schematic of the stirring and dispersing apparatus used in the examples of the present invention View from above of the stirring and dispersing device used in the examples of the present invention Schematic of the stirring and dispersing apparatus used in the examples of the present invention View from above of the stirring and dispersing device used in the examples of the present invention Schematic of the stirring and dispersing apparatus used in the examples of the present invention View from above of the stirring and dispersing device used in the examples of the present invention Schematic of calculation method of softening point (melting temperature in 1/2 method) of binder resin by flow tester of the present invention A photograph (3000 times) showing an SEM observation image of the core particles in this example A photograph (3000 times) showing an SEM observation image of the core particles in this example Photograph showing SEM observation image of core particle in comparative example (3000 times) Photograph showing SEM observation image of core particle in comparative example (3000 times)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging roller 3 Laser signal light 4 Developing roller 5 Blade 10 1st transfer roller 12 Transfer belt 13 Drive tension roller 14 2nd transfer roller 17 Transfer belt unit 18B, 18C, 18M, 18Y Image forming unit 18 Image forming unit Group 201 Fixing roller 202 Pressure roller 203 Fixing belt 205 Induction heater unit 206 Ferrite core 207 Coil 801 Outer tank 802 Dam plate 803 Rotating body 806 Shaft 807 Cooling water discharge port 808 Cooling water injection port

Claims (32)

Colored particles produced by mixing and aggregating at least a resin particle dispersion in which resin particles are dispersed, a pigment particle dispersion in which pigment particles are dispersed, and a wax particle dispersion in which wax particles are dispersed in an aqueous medium. A toner containing
The pigment particles include at least a quinacridone pigment and a naphthol pigment,
The weight blending ratio of the quinacridone pigment and the naphthol pigment is 1: 1 to 1: 9,
In the volume particle size distribution of the quinacridone pigment particle dispersion in which the quinacridone pigment particles are dispersed, in the volume particle size cumulative distribution when accumulated from the small particle size side, the particle size that becomes 16% cumulative is PQ16. Assuming that the particle size of 50% is PQ50 and the particle size of 84% cumulative is PQ84, PQ16 is 20 to 150 nm, PQ50 is 40 to 250 nm, PQ84 is 350 nm or less, and PQ84 / PQ16 is 1.2 to 2.5. Yes,
In the volume particle size distribution of the naphthol pigment particle dispersion in which the naphthol pigment particles are dispersed, the cumulative particle size distribution from the small particle size side is PN16. Assuming that the particle size of 50% is PN50 and the particle size of 84% is PN84, PN16 is 20 to 150 nm, PN50 is 40 to 250 nm, PN84 is 350 nm or less, and PN84 / PN16 is 1.2 to 2.5. A toner characterized by being. In the volume particle size distribution of the quinacridone pigment particle dispersion in which the quinacridone pigment particles are dispersed, the volume particle size cumulative distribution when accumulated from the small particle size side is PQ16. Assuming that the particle size of 50% is PQ50 and the particle size of 84% cumulative is PQ84, PQ16 is 20 to 80 nm, PQ50 is 40 to 180 nm, PQ84 is 250 nm or less, and PQ84 / PQ16 is 1.2 to 2.0. Yes,
In the volume particle size distribution of the naphthol pigment particle dispersion in which the naphthol pigment particles are dispersed, the cumulative particle size distribution from the small particle size side is PN16. PN50 is 50 to 80 nm, PN50 is 40 to 180 nm, PN84 is 250 nm or less, and PN84 / PN16 is 1.2 to 2.0. The toner according to claim 1. In the volume particle size distribution of the quinacridone pigment particle dispersion in which the quinacridone pigment particles are dispersed, the volume particle size cumulative distribution when accumulated from the small particle size side is PQ16. Assuming that the particle size of 50% is PQ50 and the particle size of 84% cumulative is PQ84, PQ16 is 20 to 60 nm, PQ50 is 40 to 120 nm, PQ84 is 220 nm or less, and PQ84 / PQ16 is 1.2 to 1.8. Yes,
In the volume particle size distribution of the naphthol pigment particle dispersion in which the naphthol pigment particles are dispersed, the cumulative particle size distribution from the small particle size side is PN16. Assuming that the particle size of 50% is PN50 and the particle size of 84% is PN84, PN16 is 20 to 60 nm, PN50 is 40 to 120 nm, PN84 is 220 nm or less, and PN84 / PN16 is 1.2 to 1.8. The toner according to claim 1. The toner according to claim 1, wherein the quinacridone pigment particle dispersion and the naphthol pigment particle dispersion satisfy the relationship (Equation 1).
In the quinacridone pigment particle dispersion in which the quinacridone pigment particles are dispersed, a nonionic surfactant and an anionic surfactant are included at a polymerization blend ratio of 1: 1 to 5: 1, and
In the naphthol pigment particle dispersion in which the naphthol pigment particles are dispersed, a nonionic surfactant and an anionic surfactant are included at a polymerization blending ratio of 1: 1 to 5: 1.
The weight blending amount of the nonionic surfactant in the naphthol pigment particle dispersion is 1.1 to 5 times that of the nonionic surfactant in the quinacridone pigment particle dispersion. The toner described. The toner according to claim 5, wherein the nonionic surfactant has an HLB (Hydrophile-Lipophile Balance) of 13.3 to 18.6. 6. The toner according to claim 5, wherein the anionic surfactant is at least one selected from a higher alcohol sulfate, a higher alkyl ether sulfate, an alkylbenzene sulfonate, and an alkylnaphthalene sulfonate. The toner according to claim 1, wherein the wax comprises an ester wax having an endothermic peak temperature (referred to as Tmw1 (° C.)) of 30 to 90 ° C. by DSC. The toner according to claim 1 or 8, wherein the ester wax contains an ester wax composed of at least one of a higher alcohol having 16 to 24 carbon atoms and a higher fatty acid having 16 to 24 carbon atoms. The toner according to claim 1 or 8, wherein the ester wax contains an ester wax having an iodine value of 25 or less and a saponification value of 30 to 300. The toner according to claim 1, wherein the wax particle dispersion contains 3 to 20 parts by weight of polypropylene glycol ethylene oxide adduct with respect to 100 parts by weight of wax particles. The toner according to claim 11, wherein the weight average molecular weight of the hydrophobic group portion of the polypropylene glycol ethylene oxide adduct is 1750 or more and 3850 or less. 12. The toner according to claim 11, wherein the ethylene oxide in the total molecule of the polypropylene glycol ethylene oxide adduct is 40 wt% or more and 80 wt% or less. The toner according to claim 1, wherein the wax particle dispersion contains 0.1 to 10 parts by weight of a polymer dispersant with respect to 100 parts by weight of the wax particles. The toner according to claim 14, wherein the polymer-based dispersant includes a maleic acid-based dispersant or an acrylic acid-based dispersant, and the polymer-based dispersant has a glass transition point of 40 to 150 ° C. and a softening point of 90 to 220 ° C. . The polymer dispersant is at least one selected from a styrene-acrylic acid copolymer, a styrene-maleic acid copolymer, a styrene-maleic acid half ester copolymer, an acrylate-maleic acid copolymer, and salts thereof. The toner according to claim 14 or 15, comprising one substance. Mixing at least a resin particle dispersion in which resin particles are dispersed, a pigment particle dispersion in which pigment particles are dispersed, and a wax particle dispersion in which wax particles are dispersed in an aqueous medium to form a mixed solution; ,
A method for producing a toner comprising a step of adding a flocculant to the mixed solution and aggregating the resin particles, the pigment particles, and the wax particles to produce colored particles,
The pigment particles include at least a quinacridone pigment and a naphthol pigment,
The weight blending ratio of the quinacridone pigment and the naphthol pigment is 1: 1 to 1: 9,
In the volume particle size distribution of the quinacridone pigment particle dispersion in which the quinacridone pigment particles are dispersed, in the volume particle size cumulative distribution when accumulated from the small particle size side, the particle size that becomes 16% cumulative is PQ16. Assuming that the particle size of 50% is PQ50 and the particle size of 84% cumulative is PQ84, PQ16 is 20 to 150 nm, PQ50 is 40 to 250 nm, PQ84 is 350 nm or less, and PQ84 / PQ16 is 1.2 to 2.5. Yes,
In the volume particle size distribution of the naphthol pigment particle dispersion in which the naphthol pigment particles are dispersed, the cumulative particle size distribution from the small particle size side is PN16. Assuming that the particle size of 50% is PN50 and the particle size of 84% is PN84, PN16 is 20 to 150 nm, PN50 is 40 to 250 nm, PN84 is 350 nm or less, and PN84 / PN16 is 1.2 to 2.5. A method for producing a toner, comprising: In the volume particle size distribution of the quinacridone pigment particle dispersion in which the quinacridone pigment particles are dispersed, the volume particle size cumulative distribution when accumulated from the small particle size side is PQ16. Assuming that the particle size of 50% is PQ50 and the particle size of 84% cumulative is PQ84, PQ16 is 20 to 80 nm, PQ50 is 40 to 180 nm, PQ84 is 250 nm or less, and PQ84 / PQ16 is 1.2 to 2.0. Yes,
In the volume particle size distribution of the naphthol pigment particle dispersion in which the naphthol pigment particles are dispersed, the cumulative particle size distribution from the small particle size side is PN16. PN50 is 50 to 80 nm, PN50 is 40 to 180 nm, PN84 is 250 nm or less, and PN84 / PN16 is 1.2 to 2.0. The method for producing a toner according to claim 17. In the volume particle size distribution of the quinacridone pigment particle dispersion in which the quinacridone pigment particles are dispersed, the volume particle size cumulative distribution when accumulated from the small particle size side is PQ16. Assuming that the particle size of 50% is PQ50 and the particle size of 84% cumulative is PQ84, PQ16 is 20 to 60 nm, PQ50 is 40 to 120 nm, PQ84 is 220 nm or less, and PQ84 / PQ16 is 1.2 to 1.8. Yes,
In the volume particle size distribution of the naphthol pigment particle dispersion in which the naphthol pigment particles are dispersed, the cumulative particle size distribution from the small particle size side is PN16. Assuming that the particle size of 50% is PN50 and the particle size of 84% is PN84, PN16 is 20 to 60 nm, PN50 is 40 to 120 nm, PN84 is 220 nm or less, and PN84 / PN16 is 1.2 to 1.8. The method for producing a toner according to claim 17. 18. The method for producing a toner according to claim 17, wherein the quinacridone pigment particle dispersion and the naphthol pigment particle dispersion satisfy the relationship of (Equation 2).
In the quinacridone pigment particle dispersion in which the quinacridone pigment particles are dispersed, the nonionic dispersant and the anionic dispersant are included at a polymerization blend ratio of 1: 1 to 5: 1, and
In the naphthol pigment particle dispersion in which the naphthol pigment particles are dispersed, the nonionic dispersant and the anionic dispersant are included in a polymerization blend ratio of 1: 1 to 5: 1.
The toner manufacturing method according to claim 17, wherein a weight blending amount of the nonionic dispersant in the naphthol pigment particle dispersion is 1.1 to 5 times that of the nonionic dispersant in the quinacridone pigment particle dispersion. The toner production method according to claim 21, wherein the nonionic surfactant has an HLB (Hydrophile-Lipophile Balance) of 13.3 to 18.6. The method for producing a toner according to claim 21, wherein the anionic surfactant is at least one selected from a higher alcohol sulfate, a higher alkyl ether sulfate, an alkylbenzenesulfonate, and an alkylnaphthalenesulfonate. 18. The method for producing a toner according to claim 17, wherein the wax contains an ester wax having an endothermic peak temperature (referred to as Tmw1 (° C.)) of 30 to 90 ° C. by DSC method. 25. The method for producing a toner according to claim 17 or 24, wherein the ester wax includes an ester wax composed of at least one of a higher alcohol having 16 to 24 carbon atoms and a higher fatty acid having 16 to 24 carbon atoms. The method for producing a toner according to claim 17 or 24, wherein the ester wax contains an ester wax having an iodine value of 25 or less and a saponification value of 30 to 300. The toner production method according to claim 17, wherein the wax particle dispersion contains 3 to 20 parts by weight of a polypropylene glycol ethylene oxide adduct with respect to 100 parts by weight of the wax particles. 28. The method for producing a toner according to claim 27, wherein the weight average molecular weight of the hydrophobic group portion of the polypropylene glycol ethylene oxide adduct is 1750 or more and 3850 or less. 28. The method for producing a toner according to claim 27, wherein the ethylene oxide in the total molecule of the polypropylene glycol ethylene oxide adduct is 40 wt% or more and 80 wt% or less. 18. The method for producing a toner according to claim 17, wherein the wax particle dispersion contains 0.1 to 10 parts by weight of a polymer dispersant with respect to 100 parts by weight of the wax particles. The toner according to claim 30, wherein the polymer dispersant includes a maleic acid dispersant or an acrylic acid dispersant, and the polymer dispersant has a glass transition point of 40 to 150 ° C and a softening point of 90 to 220 ° C. Manufacturing method. The polymer dispersant is at least one selected from a styrene-acrylic acid copolymer, a styrene-maleic acid copolymer, a styrene-maleic acid half ester copolymer, an acrylate-maleic acid copolymer, and salts thereof. 32. The method for producing a toner according to claim 30, comprising one substance.