JP6413513B2 - Method for producing toner for developing electrostatic image - Google Patents

Description

The present invention relates to a method for producing a toner for developing electrostatic images used in electrophotographic image formation.

In recent years, in the field of electrophotographic image forming apparatuses, development of an electrostatic charge image developing toner (hereinafter also simply referred to as “toner”) suitable for the demand has been made in accordance with a demand from the market. For example, from the viewpoint of energy saving, development of a low-temperature fixing toner that can be fixed with less energy is in progress. As the low-temperature fixing toner, for example, a soft resin having a low melting temperature or melt viscosity may be used as the binder resin. However, the softer the resin, the lower the heat-resistant storage property and the lower the internal cohesion of the toner particles. As a result, fixing separation at the time of heat fixing is lowered.
In order to obtain both low-temperature fixability and heat-resistant storage properties, for example, a toner using a polyester resin has been developed. Polyester resin has the advantage that it can be easily designed to have a low softening point while maintaining a high glass transition point compared to styrene acrylic resin. A toner excellent in both properties can be obtained.

  As a toner using a polyester resin, Patent Document 1 discloses a toner made of toner particles in which a release agent (wax) is dispersed as a domain phase in a binder resin made of a polyester resin. This toner basically has both low-temperature fixability and heat-resistant storage properties, and furthermore, a certain degree of heat-resistant storage properties can be obtained by preventing the exposure of the wax to the surface of the toner particles.

  However, since the SP value of polyester resin and wax are usually greatly different from each other, the wax easily oozes to the surface of the toner particles during storage in a high temperature and high humidity environment, and sufficient heat-resistant storage stability is obtained. It can not be said. In addition, there is a problem that due to the large SP value difference between the polyester resin and the wax, the dispersibility of the wax in the toner particles is low, and as a result, sufficient fixing separation property cannot be obtained.

JP 2008-197288 A

The present invention was made in view of the circumstances described above, and its object is to provide a low-temperature fixability, heat-resistant storage stability and fixing separability manufacturing method of the electrostatic image developing toner obtained There is.

The method for producing an electrostatic charge image developing toner of the present invention comprises toner particles containing a binder resin having at least a polyester resin and a styrene acrylic resin, a colorant, and a release agent,
Toner particles are dispersed as a domain phase in each of a styrene acrylic resin and a release agent in a matrix phase made of a polyester resin.
A domain phase made of styrene acrylic resin and a domain phase by a release agent are independent from each other and are slightly separated from each other without being in contact with each other. A method for producing a toner for developing a charge image, comprising:
It has at least the following steps (1) and (2).
(1) In an aqueous medium in which fine particles of a styrene acrylic modified polyester resin formed by bonding a polyester polymerization segment and a styrene acrylic polymerization segment are dispersed, a styrene monomer, a (meth) acrylic acid ester monomer, and By adding an oil-soluble polymerization initiator and performing seed polymerization with the styrene monomer and the (meth) acrylate monomer using the fine particles of the styrene acrylic modified polyester resin as seed particles, A step of producing seed polymer resin fine particles containing a styrene acrylic resin obtained by polymerizing a monomer and a (meth) acrylic acid ester monomer and having the polyester polymer segment oriented on the surface (2) Aqueous medium The seed polymer resin fine particles, the release agent fine particles, and the colorant fine particles. A process of agglomerating and fusing particles to form toner particles

  According to the toner for developing an electrostatic charge image of the present invention, in the toner particles, a domain phase composed of a styrene acrylic resin and a domain phase composed of a release agent are present adjacent to each other in a matrix phase composed of a polyester resin. , Low temperature fixability, heat-resistant storage property and fixing separation property can be obtained.

  According to the method for producing a toner for developing an electrostatic charge image of the present invention, the toner for developing an electrostatic charge image capable of obtaining low-temperature fixability, heat-resistant storage property and fixing separation property can be reliably produced.

FIG. 3 is a schematic diagram showing a cross-sectional structure of toner particles according to the present invention.

  Hereinafter, the present invention will be specifically described.

The toner of the present invention comprises toner particles containing at least a binder resin having a polyester resin and a styrene acrylic resin, a colorant and a release agent, and the toner particles are contained in a matrix phase comprising a polyester resin and a styrene acrylic resin and Each of the release agents has a sea-island structure in which the release agent is dispersed as a domain phase. As shown in FIG. 1, a domain phase (hereinafter, also referred to as “styrene acrylic domain phase”) 12 made of the styrene acrylic resin. And a domain phase (hereinafter, also referred to as “wax domain phase”) 15 due to the releasing agent is present adjacently.
In the present invention, the sea (matrix phase 11) in the sea-island structure means a continuous phase, and the islands (domain phases 12, 15) mean a discontinuous phase (dispersed phase) surrounded by the sea (matrix phase 11).
Further, “the styrene acrylic domain phase and the wax domain phase are present adjacent to each other” means that they are present in the matrix phase as independent domain phases, and are in contact with each other or close to each other. It means that it is slightly separated in the state. In the case of being separated, the separation distance is preferably 5 nm or less.

The formation of the sea-island structure as described above in the toner particles can be confirmed by observing the cross section of the toner particles using a scanning transmission electron microscope as follows.
<Method for observing cross section of toner particles>
(1. Overview)
Apparatus: Scanning transmission electron microscope “JSM-7401F” (manufactured by JEOL Ltd.)
Sample: section of toner particles stained with ruthenium tetroxide (RuO ₄ ) (section thickness: 100-200 nm)
Acceleration voltage: 30 kV
Magnification: 10,000 times, bright field image (2. Method for preparing a section of toner particles)
The toner is dispersed in a photocurable resin “D-800” (manufactured by JEOL Ltd.) and then photocured to form a block. Next, using a microtome equipped with diamond teeth, a flaky sample having a thickness of 100 to 200 nm is cut out from the above block and placed on a grid with a support film for transmission electron microscope observation.
A filter paper is laid on a 5 cmφ plastic petri dish, and a grid on which a slice is placed is placed thereon with the surface on which the slice is placed facing up.
The staining conditions (time, temperature, concentration and amount of the staining agent) are adjusted so that each resin can be distinguished when observed with a transmission electron microscope. For example, 2 to 3 drops of 0.5% RuO ₄ staining solution is dropped on two points in the petri dish, covered, and after 10 minutes, the petri dish lid is removed and left until the water in the staining liquid is exhausted.
(3. Identification method of each resin in the observed image)
Each resin in the toner particles in the observed image is identified based on the following criteria.
-Observed as a dark region: Styrene acrylic resin-Observed as a bright region: Amorphous polyester resin-Observed as a bright region and the interface was observed dark: Release agent

According to the above toner, since the styrene acrylic domain phase 12 and the wax domain phase 15 are present adjacent to each other in the matrix phase 11 made of polyester resin in the toner particles, low temperature fixability, heat resistant storage stability and fixing. Separability is obtained.
This is due to the following reason. First, by using an amorphous polyester resin as a binder resin, it is possible to obtain both low-temperature fixability and heat-resistant storage stability. Moreover, since the styrene acrylic resin is dispersed as the domain phase, the release agent can be finely dispersed in the toner particles as the wax domain phase 15. As a result, excellent fixing and separating properties can be obtained. By the presence of the wax domain phase 15 adjacent to the styrene acrylic domain phase 12, it is possible to suppress the seepage of the release agent to the surface of the toner particles even during storage in a high temperature and high humidity environment. It is considered that better heat-resistant storage stability can be obtained.
The reason why the release agent is finely dispersed in the toner particles is that the SP value difference between the release agent and the styrene acrylic resin is usually smaller than the SP value difference between the polyester resin and the styrene acrylic domain phase 12 and the wax domain phase. This is presumably because of the high affinity with No. 15 and, therefore, the coalescence of the release agent fine particles can be inhibited during the production of the toner.

In order to make the wax domain phase 15 and the styrene acrylic domain phase 12 adjacent to each other in the toner particles, Hansen SP value (hereinafter referred to as “Hansen”) of the styrene acrylic resin constituting the styrene acrylic domain phase 12 and the release agent is used. The HSP distance, which is the distance of the HSP vector in “HSP value”), is preferably in the range of 1 to 4 (J / cm ³ ) ^1/2 . The HSP distance between the release agent and the polyester resin is 6 to 11 (J / cm ³ ) ^1/2 , and the HSP distance between the styrene acrylic resin and the polyester resin is 5 to 7 (J / cm ³ ) ^{1 / 2} is preferred.
When the HSP distances of the styrene acrylic resin, the release agent, and the polyester resin are in the above ranges, the wax domain phase 15 in the matrix phase 11 of the polyester resin depends on the balance of affinity among the resins and the release agent. And the styrene acrylic domain phase 12 can be made adjacent to each other.
This is because when the HSP distance is in the above range, the styrene acrylic resin and the release agent fine particles contained in the seed polymer resin fine particles are aggregated in the aggregation and fusion process in the toner production method described later. It is estimated that it is easy to do.

(HSP value)
HSP value (Hansen solubility parameter) means the solubility parameter (SP value) as shown in the following formula (1): dispersion term (dD), polar term (dP), hydrogen bond term (dH) It is divided into three and is considered as a three-dimensional vector. The substance-specific HSP value is defined as shown in the following formula (2). This idea proposed by Hansen is described in “Chemical Industry Co., Ltd., March 2010 issue of Hiroshi Yamamoto, Steven Abbott, Charles M. Hansen”.
Formula (1): HSP value = (dD ² + dP ² + dH ² ) ^1/2
[Where,
dD: dispersion term dP: polar term dH: hydrogen bond term. ]

(HSP distance)
The HSP distance is a distance of HSP vectors between arbitrary different substances such as a solvent and a polymer, and is an index that the smaller the HSP distance is, the easier it is to dissolve. The HSP distance is defined by the following expression (2), and this concept is described in “Chemical Industry, April 2010, Hiroshi Yamamoto, Steven Abbott, Charles M. Hansen”.
Formula (2):
HSP distance = (4 × (dD ₁ −dD ₂ ) ² + (dP ₁ −dP ₂ ) ² + (dH ₁ −dH ₂ ) ² ) ^1/2
[Where,
dD ₁ : Dispersion term of any substance 1 dD ₂ : Dispersion term of any substance 2 dP ₁ : Polar term of any substance 1 dP ₂ : Polar term of any substance 2 dH ₁ : Hydrogen bond of any substance 1 Term dH ₂ : hydrogen bonding term of any substance 2 ]

In the present invention, the HSP value and the HSP distance are specifically obtained as follows.
1) Group molar traction constants (Fdi, Fpi, Ehi) and molar volume (Vi) of each functional group are determined according to “PROPERIES OF POLYMERS” (author: DW VAN KREVELEN, publisher: ELSEVIER SCIENTIFIC PUBLISHING COMPANY, 1989). It is calculated according to the description items and technique of “CHAPTER7 COHESIVE PROPERITES AND SOLUBILITY” (pages 129 to 158) of the fifth edition).
2) The unit group molar pulling constant of the polymer (resin) is calculated from the group molar pulling constants (Fdi, Fpi, Ehi) and the molar volume (Vi) of each functional group determined in 1) above.
Formula (3)
dD = ΣFdi / ΣVi
Formula (4)
dP = (Σ (Fpi) ² ) ^1/2 / ΣVi
Formula (5)
dH = (ΣEhi / ΣVi) ^1/2
It calculates by said Formula (3), Formula (4), and Formula (5), respectively.
3) For a polymer (copolymer) containing a plurality of monomer units, it is calculated by multiplying the molar ratio of each unit monomer.

〔Release agent〕
In the toner particles according to the present invention, the release agent is dispersed as the wax domain phase 15 in the matrix phase 11 made of polyester resin.

The number average domain diameter of the wax domain phases 15 is preferably 50 to 300 nm.
When the number average domain diameter of the wax domain phases 15 is 50 nm or more, sufficient releasability can be obtained at the time of fixing. On the other hand, when the number-average domain diameter of the wax domain phases 15 is 300 nm or less, a sufficiently finely dispersed state is obtained, and excellent fixing separation properties are surely obtained.

<Method for measuring the number average domain diameter of wax domain phases>
The number average domain diameter of the wax domain phases 15 is measured using the above-described method for observing the cross section of the toner particles. That is, first, 25 toner particle images in which a cross section with the maximum area in the toner particles (hereinafter also referred to as “maximum cross section”) is observed are arbitrarily selected, and the 25 toner particle images having the maximum cross section are imaged. The analysis is performed by a processing analyzer “LUZEX (registered trademark) AP” (manufactured by Nireco). Next, the number of wax domain phases 15 is selected by arbitrarily selecting 200 wax domain phases in the 25 toner particle images of the maximum cross section, measuring the horizontal ferret diameter thereof, and calculating the arithmetic average value thereof. An average domain diameter is obtained.
The horizontal ferret diameter of the wax domain phase refers to the length of a side parallel to the x axis of the circumscribed rectangle when the domain phase image is binarized.
The toner particle image of the maximum cross section is a toner particle in which the average diameter of the toner particle image is within a volume-based median diameter (D ₅₀ ) ± 10% measured by a method for measuring the average particle diameter of toner described later. Say a statue. In order to arbitrarily select 25 toner particle images, the cross-section of the toner particles may be observed for a plurality of fields as necessary.
The average diameter of the toner particle image is a value calculated by the average value (s + t) / 2 of the longest diameter s and the shortest diameter t of the toner particle image.

The release agent is not particularly limited, and various known waxes can be used. For example, polyolefin waxes such as polyethylene wax and polypropylene wax, branched hydrocarbon waxes such as microcrystalline wax, and paraffins. Long-chain hydrocarbon waxes such as wax and sazol wax, dialkyl ketone waxes such as distearyl ketone, carnauba wax, montan wax, behenate behenate, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, penta Ester wacks such as erythritol diacetate dibehenate, glycerin tribehenate, 1,18-octadecanediol distearate, tristearyl trimellitic acid, distearyl maleate , Ethylenediamine behenyl amide, an amide-based waxes such as trimellitic acid tristearyl amide.
The content ratio of the release agent is usually 2 to 20 parts by mass with respect to 100 parts by mass of the binder resin, more preferably 3 to 18 parts by mass, and particularly preferably 4 to 15 parts by mass. When the content ratio of the release agent is within the above range, sufficient fixing separation property can be obtained.
Among these, from the viewpoint of releasability at low temperature fixing, it is preferable to use those having a low melting point, specifically, those having a melting point of 50 to 95 ° C.

[Binder resin]
The binder resin is composed of at least a polyester resin and a styrene acrylic resin. Styrene acrylic resin is a resin that exhibits high viscoelasticity at high temperatures, and contributes to improvement in fixing separation and high-temperature offset resistance. On the other hand, the polyester resin is a resin having an excellent sharp melt property while maintaining a high glass transition point (Tg) as compared with the styrene acrylic resin. The high glass transition point is excellent in heat storage stability and fixing separation property. The effect can be exhibited, and the effect of excellent low-temperature fixability can be exhibited by the sharp melt property.
In the present invention, the binder resin may contain a polyester resin and a styrene acrylic resin, but other resins may be contained within a range not exceeding the content of the styrene acrylic resin. The other resin preferably contains a crystalline polyester resin.

[Styrene acrylic resin]
The styrene acrylic resin constituting the styrene acrylic domain phase 12 is a copolymer formed using a styrene monomer and a (meth) acrylate monomer.

The number average domain diameter of the styrene acrylic domain phase 12 is 30 to 150 nm, preferably 60 to 100 nm.
When the number average domain diameter of the styrene acrylic domain phase 12 is 30 nm or more, it is possible to easily control the aggregation of the seed polymer resin fine particles (S) during the production of the toner. On the other hand, when the number average domain diameter of the styrene acrylic domain phase 12 is 150 nm or less, toner particles in which the wax domain phase 15 is finely dispersed can be obtained.
The number average domain diameter of the styrene acrylic domain phase 12 is determined by measuring the horizontal ferret diameter of the styrene acrylic domain phase 12 instead of the wax domain phase 15 in the method of measuring the number average domain diameter of the wax domain phase 15 described above. Everything else is measured in the same way.

Below, the styrene-type monomer and (meth) acrylic acid ester-type monomer which can be used in order to form a styrene acrylic resin are shown.
The styrenic monomers and (meth) acrylic acid ester monomers exemplified below can be used singly or in combination of two or more.

Examples of the styrene monomer include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, p-ethylstyrene, and pn. -Butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, 2,4- Examples include dimethylstyrene and 3,4-dichlorostyrene.
Examples of (meth) acrylate monomers include, for example, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, hexyl acrylate, cyclohexyl acrylate, and heptyl acrylate. , Phenyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, heptyl methacrylate, β-hydroxyethyl acrylate, γ- Examples thereof include propyl aminoacrylate, stearyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate and the like.

In addition to the above styrene monomer and (meth) acrylic acid ester monomer, other vinyl monomers can be used. As other vinyl monomers, the following can also be used.
・ Vinyl esters Vinyl propionate, vinyl acetate, vinyl benzoate, etc.
・ Vinyl ethers Vinyl methyl ether, vinyl ethyl ether, etc.
・ Vinyl ketones Vinyl methyl ketone, vinyl ethyl ketone, vinyl hexyl ketone, etc.
N-vinyl compounds N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone and the like.
・ Others Vinyl compounds such as vinyl naphthalene and vinyl pyridine, acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile and acrylamide.

Moreover, the polymerizable monomer which has an acid group can be used as another vinyl monomer. The polymerizable monomer having an acid group refers to a monomer having an ionic dissociation group such as a carboxy group, a sulfonic acid group, and a phosphoric acid group. Specifically, there are the following.
Examples of the monomer having a carboxy group include acrylic acid, methacrylic acid, maleic acid, itaconic acid, cinnamic acid, fumaric acid, maleic acid monoalkyl ester, itaconic acid monoalkyl ester, and the like. Examples of the monomer having a sulfonic acid group include styrene sulfonic acid, allyl sulfosuccinic acid, and 2-acrylamido-2-methylpropane sulfonic acid. Furthermore, examples of the monomer having a phosphate group include acid phosphooxyethyl methacrylate.

Furthermore, polyfunctional vinyls can be used as other vinyl monomers, and the styrene acrylic resin can have a crosslinked structure. Polyfunctional vinyls include divinylbenzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol Examples include diacrylate.
When polyfunctional vinyls are used, the copolymerization ratio with respect to the whole monomer is usually 0.001 to 5% by mass, preferably 0.003 to 2% by mass, more preferably 0.01 to 1% by mass. It is. By using polyfunctional vinyls, a gel component insoluble in tetrahydrofuran is generated, and the proportion of the gel component in the whole polymer is usually 40% by mass or less, preferably 20% by mass or less. Is done.

[Molecular weight of styrene acrylic resin]
The styrene acrylic resin preferably has a weight average molecular weight (Mw) calculated from a molecular weight distribution measured by gel permeation chromatography (GPC) of 20,000 to 60,000.
When the weight average molecular weight (Mw) of the styrene acrylic resin is 20,000 or more, sufficient heat-resistant storage stability is obtained. Further, when the weight average molecular weight (Mw) of the styrene acrylic resin is 60,000 or less, sufficient low-temperature fixability can be obtained.

Measurement of molecular weight distribution by GPC was performed as follows. That is, using an apparatus “HLC-8220” (manufactured by Tosoh Corporation) and a column “TSKguardcolumn + TSKgelSuperHZM-M3 series” (manufactured by Tosoh Corporation), tetrahydrofuran (THF) as a carrier solvent at a flow rate of 0. Flow at 2 ml / min, and dissolve the measurement sample (styrene acrylic resin) in tetrahydrofuran to a concentration of 1 mg / ml under a dissolution condition in which treatment is performed for 5 minutes using an ultrasonic disperser at room temperature, and then the pore size is 0.2 μm. A sample solution is obtained by processing with a membrane filter, and 10 μL of this sample solution is injected into the apparatus together with the carrier solvent described above, detected using a refractive index detector (RI detector), and the molecular weight distribution of the measurement sample is determined. Calibration measured using monodisperse polystyrene standard particles Calculate using lines. As a standard polystyrene sample for calibration curve measurement, molecular weights manufactured by Pressure Chemical Co., Ltd. are 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1 .1 × 10 ⁵ , 3.9 × 10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ , and at least about 10 standard polystyrene samples were measured, and a calibration curve It was created. A refractive index detector was used as the detector.

[Glass transition point of styrene acrylic resin]
It is preferable that the glass transition point of a styrene acrylic resin is 40-60 degreeC, More preferably, it is 45-55 degreeC.
Sufficient heat-resistant storage property is acquired because the glass transition point of a styrene acrylic resin is 40 degreeC or more. On the other hand, when the glass transition point of the styrene acrylic resin is 60 ° C. or less, sufficient low-temperature fixability can be obtained.

The glass transition point (Tg) of the styrene acrylic resin is a value measured using “Diamond DSC” (manufactured by PerkinElmer).
As a measurement procedure, 3.0 mg of a measurement sample (styrene acrylic resin) is sealed in an aluminum pan and set in a holder. The reference used an empty aluminum pan. The measurement conditions were a measurement temperature of 0 ° C. to 200 ° C., a temperature increase rate of 10 ° C./min, a temperature decrease rate of 10 ° C./min, and heat-cool-heat temperature control. Perform analysis based on the data in Heat, draw a baseline extension before the rise of the first endothermic peak, and a tangent line indicating the maximum slope between the rise of the first peak and the peak apex, Let the intersection be the glass transition point.

  The content ratio of the styrene acrylic resin in the binder resin is preferably 2 to 20% by mass.

[Polyester resin]
The polyester resin constituting the matrix phase 11 is preferably an amorphous polyester resin. The amorphous polyester resin is a polyester resin obtained by polycondensation of at least a polyhydric alcohol component and a polyvalent carboxylic acid component and having no clear endothermic peak in differential scanning calorimetry (DSC). .
In the present invention, the amorphous polyester resin may be a styrene acrylic modified amorphous polyester resin formed by bonding a styrene acrylic polymer segment and an amorphous polyester polymer segment.

  As the polyvalent carboxylic acid component for forming the amorphous polyester resin, polyvalent carboxylic acid and alkyl esters thereof, acid anhydrides and acid chlorides can be used. Alcohols and their ester compounds and hydroxycarboxylic acids can be used.

Examples of the polyvalent carboxylic acid include aromatic carboxylic acids such as terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid, naphthalene dicarboxylic acid, naphthalene tricarboxylic acid, naphthalene tetracarboxylic acid; maleic anhydride, Aliphatic carboxylic acids such as fumaric acid, succinic acid, alkenyl succinic anhydride, and adipic acid; and alicyclic carboxylic acids such as cyclohexanedicarboxylic acid. Among these polyvalent carboxylic acids, linear alkyl groups are not included. In addition, it is preferable to use an aromatic carboxylic acid, and for the purpose of forming a crosslinked structure or a branched structure to ensure good fixability, a trivalent or higher carboxylic acid (trivalent or trivalent) is used together with a dicarboxylic acid. It is preferable to use merit acid or its acid anhydride in combination
The polyvalent carboxylic acid component is not limited to one type, and two or more types may be mixed and used.

Examples of the polyhydric alcohol include aliphatic diols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, octanediol, decanediol, dodecanediol, and neopentylglycol; Alicyclic diols such as methanol; aromatic diols such as ethylene oxide adducts of bisphenol A and propylene oxide adducts of bisphenol A, etc. Among these polyhydric alcohols, no linear alkyl group is included. It is preferable to use those, more preferably aromatic diols or alicyclic diols, and more preferably aromatic diols. In addition, for the purpose of ensuring good fixability by forming a crosslinked structure or a branched structure, trihydric or higher alcohols (glycerin, trimethylolpropane, pentaerythritol, hexamethylolmelamine, hexaethylolmelamine, tetramethylolbenzoguanamine are used together with diol. And tetraethylol benzoguanamine) are preferably used in combination.
The polyhydric alcohol component is not limited to one type, and two or more types may be mixed and used.

The method for producing the amorphous polyester resin is not particularly limited, and can be produced using a general polyester polymerization method in which a polyvalent carboxylic acid component and a polyhydric alcohol component are reacted under a catalyst. The direct polycondensation or the transesterification method is preferably used in accordance with the type of monomer.
The polymerization temperature can be carried out between 180 and 230 ° C., and the reaction is carried out while reducing the pressure in the reaction system as necessary to remove water and alcohol generated during condensation.
When the monomer is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added as a solubilizer and dissolved. In the polycondensation reaction, the dissolution auxiliary solvent is distilled off. In the case where a monomer having low compatibility exists in the copolymerization reaction, it is preferable that the monomer having low compatibility and the monomer and the acid or alcohol to be polycondensed are condensed in advance and then polycondensed together with the main component.

Examples of the catalyst that can be used for the production of the amorphous polyester resin include alkali metal compounds such as sodium and lithium; alkaline earth metal compounds such as magnesium and calcium; zinc, manganese, antimony, titanium, tin, zirconium, Examples thereof include metal compounds such as germanium; phosphorous acid compounds; phosphoric acid compounds; and amine compounds.
Specifically, sodium acetate, sodium carbonate, lithium acetate, lithium carbonate, calcium acetate, calcium stearate, magnesium acetate, zinc acetate, zinc stearate, zinc naphthenate, zinc chloride, manganese acetate, manganese naphthenate, titanium tetraethoxy , Titanium tetrapropoxide, titanium tetraisopropoxide, titanium tetrabutoxide, antimony trioxide, triphenylantimony, tributylantimony, tin formate, tin oxalate, tetraphenyltin, dibutyltin dichloride, dibutyltin oxide, diphenyltin oxide, zirconium tetra Butoxide, Zirconium naphthenate, Zirconyl carbonate, Zirconyl acetate, Zirconyl stearate, Zirconyl octylate, Germanium oxide, Trif Alkenyl phosphite, tris (2,4-di -t- butyl-phenyl) phosphite, ethyltriphenylphosphonium bromide, triethylamine, compounds such as triphenyl amine.

  The use ratio of the polyhydric carboxylic acid component to the polyhydric alcohol component is such that the equivalent ratio [OH] / [COOH between the hydroxyl group [OH] of the polyhydric alcohol component and the carboxyl group [COOH] of the polyhydric carboxylic acid component. ] Is preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2.

As for the molecular weight measured by gel permeation chromatography (GPC) of the amorphous polyester resin, the weight average molecular weight (Mw) is preferably 1,500 to 60,000, more preferably 3,000 to 40,000. 000.
When the amorphous polyester resin has a weight average molecular weight (Mw) of 1,500 or more, a cohesive force suitable for the entire binder resin is obtained, and the occurrence of a high temperature offset phenomenon during heat fixing is suppressed. Since the amorphous polyester resin has a weight average molecular weight (Mw) of 60,000 or less, a sufficient melt viscosity can be obtained and a sufficient minimum fixing temperature can be secured. Occurrence of the phenomenon is suppressed.

  The molecular weight measurement of the amorphous polyester resin by GPC is performed in the same manner as described above except that the amorphous polyester resin is used as a measurement sample.

The glass transition point of the amorphous polyester resin is preferably 42 to 75 ° C, more preferably 45 to 70 ° C.
When the glass transition point of the amorphous polyester resin is 42 ° C. or higher, the cohesive force in the high temperature region becomes appropriate for the amorphous polyester resin, and the occurrence of the high temperature offset phenomenon during heat fixing is suppressed. . Further, when the amorphous polyester resin has a glass transition point of 75 ° C. or less, sufficient melting can be obtained at the time of heat fixing, and sufficient low-temperature fixability can be obtained.

  The glass transition point of the amorphous polyester resin is measured in the same manner as described above except that the amorphous polyester resin is used as a measurement sample.

(Styrene acrylic modified amorphous polyester resin)
The styrene acrylic modified amorphous polyester resin is formed by combining a styrene acrylic polymer segment and an amorphous polyester polymer segment.

(Styrene acrylic polymerization segment)
The styrene acrylic polymer segment is a copolymer formed using a styrene monomer and a (meth) acrylic acid ester monomer.
Styrene monomers and (meth) acrylic acid ester monomers that can be used to form styrene acrylic polymer segments include styrene monomers that can be used to form styrene acrylic resins and What was illustrated as a (meth) acrylic acid ester monomer can be used.
The styrene monomer and (meth) acrylic acid ester monomer for forming the styrene acrylic polymer segment can be used alone or in combination of two or more.

(Amorphous polyester polymerization segment)
The amorphous polyester polymer segment can have the same configuration as the above amorphous polyester resin.

The content ratio of the styrene acrylic polymer segment in the styrene acrylic modified amorphous polyester resin is preferably 1 to 30% by mass, and more preferably 5 to 10% by mass.
Specifically, the content ratio of the styrene acrylic polymerized segment is the total mass of the resin material used for synthesizing the styrene acrylic modified amorphous polyester resin, that is, the polyvalent carboxylic acid that becomes the amorphous polyester polymerized segment and Polyhydric alcohol, styrene monomer and (meth) acrylic acid ester monomer, and other vinyl monomers to be styrene acrylic polymerized segments (hereinafter collectively referred to as “specific vinyl monomers”) And the ratio of the mass of the specific vinyl monomer to the total mass of the two reactive monomers for bonding them together.
When the content of the styrene acrylic polymer segment is less than 1% by mass, there is a possibility that the vinyl monomer added later cannot be polymerized inside the particles. When the content of the styrene acrylic polymer segment exceeds 30% by mass, the domain diameter of the styrene acrylic domain phase in the obtained toner particles may be excessive.

(Method for producing styrene acrylic modified amorphous polyester resin)
The styrene acrylic modified amorphous polyester resin can be produced by bonding an amorphous polyester polymer segment and a styrene acrylic polymer segment via both reactive monomers. Specifically, it is produced by performing a polycondensation reaction in the presence of a polyvalent carboxylic acid and a polyhydric alcohol at least at any time before, during and after the step of addition polymerization of a specific vinyl monomer. be able to.
Specifically, an existing general scheme can be used. The following three methods are listed as typical methods.
(1) Polycondensation reaction of polyvalent carboxylic acid and polyhydric alcohol to form amorphous polyester polymerized segment after performing addition polymerization reaction of specific vinyl monomer to form styrene acrylic polymerized segment And, if necessary, adding a specific trivalent or higher vinyl monomer serving as a crosslinking agent to the reaction system to further advance the polycondensation reaction.
(2) Polycondensation reaction of polyvalent carboxylic acid and polyhydric alcohol to form amorphous polyester polymerized segment, followed by addition polymerization reaction of specific vinyl monomer to form styrene acrylic polymerized segment And then, if necessary, adding a specific trivalent or higher vinyl monomer serving as a cross-linking agent to the reaction system to further advance the polycondensation reaction under temperature conditions suitable for the polycondensation reaction.
(3) Addition polymerization reaction of a specific vinyl monomer for forming a styrene acrylic polymerization segment and a polyvalent carboxyl for forming an amorphous polyester polymerization segment under temperature conditions suitable for the addition polymerization reaction The polycondensation reaction of acid and polyhydric alcohol is performed in parallel, and after the addition polymerization reaction is completed, a specific vinyl monomer having a valence of 3 or more, which serves as a cross-linking agent, is added to the reaction system as necessary. A method in which the polycondensation reaction further proceeds under temperature conditions suitable for the reaction.

  Both reactive monomers are added together with a polyvalent carboxylic acid / polyhydric alcohol and / or a specific vinyl monomer.

Both reactive monomers have at least one functional group selected from the group consisting of a hydroxyl group, a carboxy group, an epoxy group, a primary amino group and a secondary amino group in the molecule, preferably a hydroxyl group and / or a carboxy group. It is preferably a compound having a group, more preferably a carboxy group and an ethylenically unsaturated bond, that is, a vinyl carboxylic acid. Specific examples of the both reactive monomers include, for example, acrylic acid, methacrylic acid, fumaric acid, maleic acid and the like, and these hydroxyalkyl (C1-3) esters may be used. From this viewpoint, it is preferable to use acrylic acid, methacrylic acid and fumaric acid.
In addition, it is preferable to use a monovalent vinyl carboxylic acid as a bi-reactive monomer rather than a polyvalent vinyl carboxylic acid from the viewpoint of toner durability. This is presumably because of the high reactivity between the monovalent vinyl carboxylic acid and the specific vinyl monomer, which facilitates hybridization. On the other hand, when a dicarboxylic acid such as fumaric acid is used as the bireactive monomer, the durability of the toner is slightly inferior. This is presumably because the reactivity between the dicarboxylic acid and the specific vinyl monomer is low and it is difficult to form a uniform hybrid, so that it takes a domain structure.

  From the viewpoint of improving the low-temperature fixability, high-temperature offset resistance and crush resistance of the toner, the amount of both reactive monomers used is 1 to 10 parts by mass with respect to 100 parts by mass of the specific vinyl monomer. Preferably, 4-8 mass parts is more preferable, 0.3-8 mass parts is preferable with respect to 100 mass parts of total amounts of polyhydric carboxylic acid and polyhydric alcohol, and 0.5-5 mass parts is more preferable.

  The addition polymerization reaction can be performed by a conventional method in the presence of a radical polymerization initiator, a crosslinking agent, or the like, in an organic solvent or in the absence of a solvent, but the temperature condition is preferably 110 to 200 ° C., and 140 to 180. ° C is more preferred. Examples of the radical polymerization initiator include dialkyl peroxide, dibutyl peroxide, butyl peroxy-2-ethylhexyl monocarboxylic acid and the like, and these can be used alone or in combination of two or more.

  The condensation polymerization reaction can be performed, for example, in an inert gas atmosphere at a temperature of 180 to 250 ° C., but is preferably performed in the presence of an esterification catalyst, a polymerization inhibitor, or the like. Examples of the esterification catalyst include tin (II) compounds having no Sn—C bond, such as dibutyltin oxide, titanium compounds, and tin octylate, and these may be used alone or in combination. it can.

The content of the amorphous polyester resin in the binder resin is preferably 5 to 70% by mass, and more preferably 10 to 20% by mass.
When the content ratio of the amorphous polyester resin is within the above range, the resin characteristics of the amorphous polyester resin are sufficiently exhibited, and excellent low-temperature fixability, heat-resistant storage property and fixing separation property can be obtained. .

(Crystalline polyester resin)
In the present invention, when the polyester resin constituting the matrix phase 11 is an amorphous polyester resin, the binder resin may further contain a crystalline polyester resin. Crystalline polyester resin contributes to low-temperature fixability as a fixing aid.
The crystalline polyester resin is preferably dispersed as the domain phase 18 in the toner particles.

The crystalline polyester resin is a polycondensation product of at least a diol component and a dicarboxylic acid component. In differential scanning calorimetry (DSC), a distinct endothermic peak (endothermic spectrum curve is not a stepwise change in endothermic amount). A polyester resin having a shape that passes through an inflection point and reaches the highest point and descends to the inflection point. The clear endothermic peak specifically means a peak in which the half-value width of the endothermic peak is within 15 ° C. when measured at a rate of temperature increase of 10 ° C./min in differential scanning calorimetry (DSC). To do.
In the present invention, the crystalline polyester resin may be a styrene acrylic modified crystalline polyester resin formed by bonding a styrene acrylic polymer segment and a crystalline polyester polymer segment.

Examples of the diol component for forming the crystalline polyester resin include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7- Heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-dodecanediol, 1,12-undecanediol, 1,13-tridecanediol, 1,14- Examples include, but are not limited to, tetradecanediol, 1,18-octadecanediol, 1,20-eicosanediol, and the like. Among these, it is preferable to use 1,9-nonanediol and 1,10-decanediol from the viewpoint of melting point and the like.
The diol component is not limited to one type, and two or more types may be mixed and used.

Examples of the dicarboxylic acid component for forming the crystalline polyester resin include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelic acid, sebacic acid, 1,9-nonanedicarboxylic acid. Acid, 1,10-decanedicarboxylic acid, 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid And aliphatic dicarboxylic acids such as 1,18-octadecanedicarboxylic acid, lower alkyl esters thereof, acid anhydrides and the like.
In addition, for example, aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, and 4,4, -biphenyldicarboxylic acid can be used. Among these, a low melting point polyester resin is formed. From the viewpoint of easiness, terephthalic acid is preferably used.
Moreover, you may use the dicarboxylic acid component which has a double bond, and the dicarboxylic acid component which has a sulfonic acid group.
The dicarboxylic acid component is not limited to one type, and two or more types may be mixed and used.

  Although it does not specifically limit as a manufacturing method of crystalline polyester resin, It can manufacture according to the manufacturing method similar to the manufacturing method of the above-mentioned amorphous polyester resin.

The molecular weight measured by gel permeation chromatography (GPC) of the crystalline polyester resin is the weight average molecular weight (from the viewpoint of the mechanical strength of the toner, the image strength and manufacturability of the obtained fixed image, and the fixability. Mw) is preferably 8,000 to 35,000, more preferably 10,000 to 30,000.
When the crystalline polyester resin has a weight average molecular weight (Mw) of 8,000 or more, offset resistance can be sufficiently obtained during heat fixing. When the crystalline polyester resin has a weight average molecular weight (Mw) of 35,000 or less, the crystalline polyester resin can be stably produced.

  The molecular weight measurement of the crystalline polyester resin by GPC is performed in the same manner as described above except that the crystalline polyester resin is used as a measurement sample.

As the crystalline polyester resin, one having a melting point of 40 to 100 ° C is preferably used, and more preferably 55 to 90 ° C.
When the melting point of the crystalline polyester resin is 40 ° C. or higher, the obtained toner has a high thermal strength and a sufficient heat-resistant storage property is obtained. In addition, when the crystalline polyester resin has a melting point of 100 ° C. or lower, sufficient low-temperature fixability can be obtained.

  Here, the melting point of the crystalline polyester resin is specifically determined by using a differential scanning calorimeter “Diamond DSC” (manufactured by Perkin Elmer Co., Ltd.) and raising the temperature from 0 ° C. to 200 ° C. at an elevation rate of 10 ° C./min. Measurement through a temperature increasing process, a cooling process for cooling from 200 ° C. to 0 ° C. at a cooling rate of 10 ° C./min, and a second temperature increasing process for increasing the temperature from 0 ° C. to 200 ° C. at a lifting speed of 10 ° C./min. Based on the DSC curve obtained by this measurement (temperature increase / cooling conditions), the melting point is the endothermic peak top temperature derived from the crystalline polyester resin in the first temperature increase process. It is. As a measurement procedure, 3.0 mg of crystalline polyester resin is sealed in an aluminum pan and set in a sample holder of “Diamond DSC”. The reference used an empty aluminum pan.

(Styrene acrylic modified crystalline polyester resin)
The styrene acrylic modified crystalline polyester resin is the same as the above styrene acrylic modified amorphous polyester resin except that the crystalline polyester polymerized segment is bonded instead of the amorphous polyester polymerized segment, It can be manufactured by a similar manufacturing method.
The crystalline polyester polymer segment can have the same configuration as the above crystalline polyester resin.

The content of the crystalline polyester resin in the binder resin is preferably 5 to 20% by mass, and more preferably 7 to 15% by mass.
When the content of the crystalline polyester resin is within the above range, the resin characteristics of the crystalline polyester resin are sufficiently exhibited in the toner, and excellent low-temperature fixability and heat-resistant storage stability are obtained.

  The molecular weight distribution, glass transition point and melting point of each resin constituting the binder resin are measured using styrene acrylic resin, amorphous polyester resin and crystalline polyester resin extracted from the toner particles as measurement samples, respectively. be able to.

[Colorant]
As the colorant, generally known dyes and pigments can be used.
As a colorant for obtaining a black toner, various known materials such as carbon black such as furnace black and channel black, magnetic materials such as magnetite and ferrite, dyes, and inorganic pigments containing nonmagnetic iron oxide are arbitrarily selected. Can be used.
As the colorant for obtaining a color toner, known ones such as dyes and organic pigments can be arbitrarily used. Specifically, examples of the organic pigment include C.I. I. Pigment Red 5, 48: 1, 53: 1, 57: 1, 81: 4, 122, 139, 144, 149, 166, 177, 178, 222, 238 269, C.I. I. Pigment Yellow 14, 17, 74, 93, 94, 138, 155, 180, 185, C.I. I. Pigment Orange 31 and 43, C.I. I. Pigment Blue 15; 3, 60, 76, and the like. Examples of the dye include C.I. I. Solvent Red 1, 49, 52, 58, 68, 11, 122, C.I. I. Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 69, 70, 93, 95 and the like.
The colorant for obtaining the toner of each color can be used singly or in combination of two or more for each color.
It is preferable that the content rate of a coloring agent is 1-30 mass parts with respect to 100 mass parts of binder resin, More preferably, it is 2-20 mass parts.

[Configuration of toner particles]
In addition to the binder resin, the colorant, and the release agent, the toner particles according to the present invention may contain an internal additive such as a charge control agent, if necessary.

[Charge control agent]
Various known compounds can be used as the charge control agent.
The content ratio of the charge control agent is usually 0.1 to 10 parts by mass, more preferably 0.5 to 5% by mass with respect to 100 parts by mass of the binder resin.

[Toner softening point]
The toner according to the present invention preferably has a softening point of 90 to 120 ° C.
When the softening point of the toner is in the above range, suitable low-temperature fixability can be obtained.

The softening point of the toner is measured by a flow tester shown below.
Specifically, first, in an environment of 20 ° C. and 50% RH, 1.1 g of a sample (toner) was placed in a petri dish and left flat for 12 hours or more, and then a molding machine “SSP-10A” (Shimadzu) Pressed with a force of 3820 kg / cm ² for 30 seconds to produce a cylindrical molded sample having a diameter of 1 cm. Then, the molded sample was subjected to a flow tester “24 ° C. and 50% RH in a flow tester“ CFT-500D "(manufactured by Shimadzu Corporation), with a load of 196 N (20 kgf), a starting temperature of 60 ° C., a preheating time of 300 seconds, and a heating rate of 6 ° C./min (1 mm diameter × 1 mm) more, extruded from the time of preheating ends with piston diameter 1 cm, offset method temperature T _offset measured by setting the offset value 5mm at a melt temperature measurement method of temperature ramps is the softening point That.

[Average toner particle size]
The average particle diameter of the toner of the present invention is preferably 3 to 8 μm, and more preferably 4 to 8 μm, for example, on a volume basis median diameter. For example, in the toner production method described later, the particle size can be controlled by the concentration of the coagulant used, the fusing time of the resin fine particles, the composition of the polymer constituting each resin, and the like.
When the volume-based median diameter is in the above range, the transfer efficiency is increased, the image quality of halftone is improved, and the image quality of fine lines and dots is improved.

  The volume-based median diameter of the toner particles is measured and calculated using a measuring device in which “Multisizer 3” (manufactured by Beckman Coulter) is connected to a computer system equipped with data processing software “Software V3.51”. Is. Specifically, 0.02 g of toner is added to 20 mL of a surfactant solution (for example, a surfactant solution obtained by diluting a neutral detergent containing a surfactant component 10 times with pure water for the purpose of dispersing toner particles). Then, ultrasonic dispersion is performed for 1 minute to prepare a toner dispersion, and this toner dispersion is placed in a beaker containing “ISOTON II” (manufactured by Beckman Coulter) in a sample stand. Pipet until the indicated concentration is 8%. Here, a reproducible measurement value can be obtained by setting the concentration range. In the measuring apparatus, the measurement particle count is 25000, the aperture diameter is 50 μm, the frequency value is calculated by dividing the measurement range of 1 to 30 μm into 256, and the volume integrated fraction is 50 % Particle diameter is defined as the volume-based median diameter.

[Average circularity of toner particles]
The toner of the present invention preferably has an average circularity of 0.850 to 0.990 from the viewpoint of improving the transfer efficiency of individual toner particles constituting the toner.

In the present invention, the average circularity of toner particles is measured using “FPIA-2100” (manufactured by Sysmex).
Specifically, the sample (toner particles) is blended with an aqueous solution containing a surfactant, subjected to ultrasonic dispersion treatment for 1 minute to disperse, and then subjected to measurement conditions HPF by “FPIA-2100” (manufactured by Sysmex). In the (high-magnification imaging) mode, photographing is performed at an appropriate density of 3,000 to 10,000 HPF detections, and the circularity of each toner particle is calculated according to the following formula (T). Calculated by adding the degree and dividing by the total number of toner particles.
Formula (T): Circularity = (perimeter of a circle having the same projection area as the particle image) / (perimeter of the particle projection image)

[Toner Production Method]
A method for producing a toner of the present invention is a method for producing a toner comprising toner particles having a binder resin containing a polyester resin and a styrene acrylic resin, a colorant, and a release agent. In this method, the seed polymer resin fine particles (S) containing the acrylic resin, the releasing agent fine particles and the colorant fine particles are aggregated and fused to produce toner particles.

  In the present invention, the “aqueous medium” refers to a medium comprising 50 to 100% by mass of water and 0 to 50% by mass of a water-soluble organic solvent. Examples of the water-soluble organic solvent include methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran, and it is preferable to use an organic solvent that does not dissolve each resin fine particle.

An example of a method for producing the toner of the present invention is specifically shown as follows:
(1) A styrene monomer and a (meth) acrylic acid ester monomer (in a water-based medium in which fine particles of a styrene acrylic modified polyester resin formed by bonding a polyester polymer segment and a styrene acrylic polymer segment are dispersed ( These are hereinafter referred to as “vinyl monomer (a) for styrene acrylic resin”), and seed polymerization with vinyl monomer (a) for styrene acrylic resin using the fine particles of the styrene acrylic modified polyester resin as seed particles. To produce seed polymer resin fine particles (S), a seed polymer resin fine particle (S) production step,
(2) Aggregate and fuse the seed polymer resin fine particles (S), the release agent fine particles and the colorant fine particles, and if necessary, the amorphous polyester resin fine particles (M) in an aqueous medium to form associated particles. Agglomeration, fusing process,
(3) An aging step of aging associated particles with thermal energy to control the shape and obtaining toner particles;
(4) a cooling step for cooling the dispersion of toner particles;
(5) A filtration / washing process for filtering the toner particles from the aqueous medium and removing the surfactant from the toner particles,
(6) a drying step of drying the washed toner particles;
(7) It can be added as necessary to the steps (1) and (2) essential to the present invention, such as an external additive addition step of adding an external additive to the dried toner particles (3). The thing which consists of a process of (7) can be mentioned.

(1) Seed polymerization resin fine particle (S) preparation process In this process, the seed polymerization resin fine particle (S) containing the styrene acrylic resin (A) and the polyester polymerization segment of the styrene acrylic resin modified polyester resin oriented on the surface ( S) is prepared. Specifically, a vinyl monomer (a) for styrene acrylic resin and an oil-soluble polymerization initiator are added to an aqueous medium in which fine particles of styrene acrylic modified polyester resin are dispersed, and the fine particles of styrene acrylic modified polyester resin are added. By performing seed polymerization with the vinyl monomer (a) for styrene acrylic resin as seed particles, the seed polymer resin fine particles (S) can be produced.

Seed polymerization refers to obtaining composite particles by adding a monomer to an emulsion containing seed particles and generating a polymerization reaction in the surface layer or inside of the seed particles.
In the present invention, by using an oil-soluble polymerization initiator together with the vinyl monomer for styrene acrylic resin (a), the polymerization reaction of the vinyl monomer for styrene acrylic resin (a) is generated inside the seed particles. The seed polymer resin fine particles (S) can have a structure in which the styrene acrylic resin (A) is contained inside and the polyester polymer segment is oriented on the surface.

Examples of the vinyl monomer (a) for styrene acrylic resin for obtaining the styrene acrylic resin (A) include the styrene monomers and (meth) acrylate monomers shown above. The above styrene monomer and (meth) acrylic acid ester monomer can be used singly or in combination of two or more.
The composition ratio of the vinyl monomer for styrene acrylic resin (a) (the type of monomer and its ratio) is the composition ratio of the monomer for forming the styrene acrylic polymer segment constituting the styrene acrylic resin modified polyester resin. May be different, but is preferably the same.

(Oil-soluble polymerization initiator)
Examples of the oil-soluble polymerization initiator include an oil-soluble peroxide polymerization initiator and an oil-soluble azo polymerization initiator. Further, a redox polymerization initiator may be formed by using the oil-soluble peroxide polymerization initiator and the reducing agent in combination, and this may be used. These oil-soluble polymerization initiators can be used singly or in combination of two or more.
Examples of oil-soluble peroxide polymerization initiators include acetyl peroxide, t-butylperoxy-2-ethylhexanoate, di-t-butylperoxyhexahydroterephthalate, benzoyl peroxide, parachlorobenzoyl peroxide, and cumene. A peroxide etc. are mentioned.
Examples of the oil-soluble azo polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis-2,4-dimethylvaleronitrile, dimethyl-2,2′-azobis (2-methylpropyl). Pionate) and 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile).
Non-aqueous redox polymerization initiators include oil-soluble peroxides such as hydroperoxides, dialkyl peroxides and diacyl peroxides, tertiary amines, naphthenates, mercaptans, organometallic compounds (triethylaluminum, triethylboron and And an oil-soluble reducing agent such as diethyl zinc).

(Chain transfer agent)
In this step, a generally used chain transfer agent can be used for the purpose of adjusting the molecular weight of the styrene acrylic resin (A). The chain transfer agent is not particularly limited, and examples thereof include mercaptans such as 2-chloroethanol, octyl mercaptan, dodecyl mercaptan, and t-dodecyl mercaptan, and styrene dimers.

(Surfactant)
The aqueous medium may contain a surfactant.
As the surfactant, conventionally known various cationic surfactants, nonionic surfactants, anionic surfactants, and the like can be used.
Specific examples of the cationic surfactant include dodecyl ammonium bromide, dodecyl trimethyl ammonium bromide, dodecyl pyridinium chloride, dodecyl pyridinium bromide, hexadecyl trimethyl ammonium bromide and the like.
Specific examples of nonionic surfactants include dodecyl polyoxyethylene ether, hexadecyl polyoxyethylene ether, norylphenyl polyoxyethylene ether, lauryl polyoxyethylene ether, sorbitan monooleate polyoxyethylene ether, styrylphenyl poly Examples thereof include oxyethylene ether and monodecanoyl sucrose.
Specific examples of the anionic surfactant include aliphatic soaps such as sodium stearate and sodium laurate, sodium lauryl sulfate, sodium dodecylbenzene sulfonate, polyoxyethylene (2) sodium lauryl ether sulfate and the like. it can.
These surfactants can be used alone or in combination of two or more as required.

The average particle diameter of the fine particles of the styrene-acrylic-modified amorphous polyester resin used as seed particles is preferably in the range of 100 to 300 nm in terms of volume-based median diameter.
When the volume-based median diameter of the styrene-acrylic-modified amorphous polyester resin fine particles is within the above range, highly uniform seed polymer resin fine particles (S) can be obtained. Can be easily aggregated.
The volume-based median diameter of the fine particles of the styrene acrylic modified amorphous polyester resin is measured using “Microtrac UPA-150” (manufactured by Nikkiso Co., Ltd.).

  The amount of the vinyl monomer (a) for styrene acrylic resin added to the seed particles is such that the content ratio of the seed particles in the obtained seed polymer resin fine particles (S) is 25 to 75 mass%, more preferably 30 to 60 mass%. Preferably, the amount is When the content ratio of the seed particles in the seed polymer resin fine particles (S) is within the above range, the seed polymer resin fine particles (S) with high uniformity can be obtained. As a result, this can be easily performed in the aggregation and fusion process. Can be agglomerated.

  The polymerization temperature of the seed polymerization is preferably the glass transition point of the styrene acrylic modified amorphous polyester resin + 30 ° C. or less, and more preferably the glass transition temperature + 20 ° C. or less.

The average particle diameter of the seed polymer resin fine particles (S) is preferably in the range of, for example, 100 to 300 nm in terms of volume-based median diameter.
When the volume-based median diameter of the seed polymer resin fine particles (S) is in the above range, it is possible to reliably manufacture toner using toner particles in which the wax domain phase 15 is finely dispersed.
The volume-based median diameter of the seed polymer resin fine particles (S) is measured using “Microtrac UPA-150” (manufactured by Nikkiso Co., Ltd.).

(2) Aggregation and fusion step In this step, seed polymer resin fine particles (S), release agent fine particles and colorant fine particles, and if necessary amorphous polyester resin fine particles (M) and other toner constituents In which the fine particles are agglomerated and further fused by heating. Specifically, an aggregating agent having a critical aggregation concentration or more is added to an aqueous medium in which these fine particles are dispersed to cause aggregation, and the fine particles are fused by setting the glass transition point or more of the resin constituting each fine particle. Put on.

The colorant fine particles are preferably subjected to this aggregation and fusion step as a dispersion in which the colorant fine particles are dispersed in an aqueous medium.
A dispersion of colorant fine particles is obtained by dispersing a colorant in an aqueous medium in which a surfactant is added to a critical micelle concentration (CMC) or higher.
The disperser used for dispersing the colorant is not particularly limited, but preferably an ultrasonic disperser, a mechanical homogenizer, a pressure disperser such as a manton gorin or a pressure homogenizer, a sand grinder, a Getzmann mill, a diamond fine mill, or the like. And a medium type dispersing machine.
The average particle diameter of the colorant fine particles in the dispersion of the colorant fine particles is preferably in the range of, for example, 10 to 200 nm in terms of volume-based median diameter. The volume-based median diameter is measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.).

The amorphous polyester resin fine particles (M) and the amorphous polyester resin, which may be unmodified or modified.
The amorphous polyester resin fine particles (M) have the same composition as the amorphous polyester polymer segment in the styrene acrylic modified amorphous polyester resin used as seed particles in the seed polymer resin fine particles (S), that is, single particles used as a raw material. It is preferable that the types and ratios of the monomers are the same.
The amorphous polyester resin fine particles (M) are preferably subjected to this aggregation and fusion step as a dispersion in which the amorphous polyester resin fine particles (M) are dispersed in an aqueous medium.
The dispersion of the amorphous polyester resin fine particles (M) can be obtained by an aqueous direct dispersion method to which a surfactant is added, for example, by an ultrasonic dispersion method or a bead mill dispersion method.
The average particle diameter of the amorphous polyester resin fine particles (M) is preferably in the range of 50 to 400 nm in terms of volume-based median diameter.
The volume-based median diameter of the amorphous polyester resin fine particles (M) is measured using “Microtrac UPA-150” (manufactured by Nikkiso Co., Ltd.).

(Flocculant)
The flocculant is not particularly limited, but a flocculant selected from metal salts such as alkali metal salts and alkaline earth metal salts is preferably used. Examples of the metal salt include monovalent metal salts such as sodium, potassium, and lithium; divalent metal salts such as calcium, magnesium, manganese, and copper; and trivalent metal salts such as iron and aluminum. Specific metal salts can include sodium chloride, potassium chloride, lithium chloride, calcium chloride, magnesium chloride, zinc chloride, copper sulfate, magnesium sulfate, manganese sulfate, and the like. It is particularly preferable to use a divalent metal salt. These can be used individually by 1 type or in combination of 2 or more types.

(3) Ripening step The ripening step is performed as necessary, and in the ripening step, the associated particles obtained in the shell layer forming step are ripened to a desired shape by thermal energy, and the toner is obtained. An aging treatment for forming particles is performed.
Specifically, the aging treatment is performed by adjusting the heating temperature, stirring speed, heating time, and the like until the shape of the associated particles reaches a desired circularity by heating and stirring the system in which the associated particles are dispersed. Done.

(4) Cooling Step This cooling step is a step of cooling the toner particle dispersion. As a condition for the cooling treatment, it is preferable to cool at a cooling rate of 1 to 20 ° C./min. The specific method of the cooling treatment is not particularly limited, and examples include a method of cooling by introducing a refrigerant from the outside of the reaction vessel, a method of cooling by directly introducing cold water into the reaction system, and the like. it can.

(5) Filtration / Washing Step The filtration / washing step involves solid-liquid separation of the toner particles from the cooled dispersion of toner particles, and a toner cake obtained by solid-liquid separation (the toner particles in a wet state are caked). This is a step of removing adhering substances such as a surfactant and an aggregating agent from the aggregate).
The solid-liquid separation is not particularly limited, and a centrifugal separation method, a vacuum filtration method using Nutsche or the like, a filtration method using a filter press, or the like can be used. Further, in washing, it is preferable to wash with water until the electric conductivity of the filtrate reaches 10 μS / cm.

(6) Drying Step This drying step is a step of drying the washed toner cake, and can be performed in accordance with a drying step in a generally known method for producing toner particles.
Specifically, examples of the dryer used for drying the toner cake include a spray dryer, a vacuum freeze dryer, and a vacuum dryer, and a stationary shelf dryer, a mobile shelf dryer, a fluidized bed, and the like. It is preferable to use a dryer, a rotary dryer, a stirring dryer or the like.
The moisture of the dried toner particles is preferably 5% by mass or less, more preferably 2% by mass or less. In addition, when the dried toner particles are aggregated by a weak interparticle attractive force, the aggregate may be crushed. Here, as the crushing treatment apparatus, a mechanical crushing apparatus such as a jet mill, a Henschel mixer, a coffee mill, or a food processor can be used.

(7) External additive addition step The above toner particles can be used as toners as they are. However, in order to improve fluidity, chargeability, cleaning properties, etc., so-called fluidizing agents and cleaning aids are added to the toner particles. You may use it in the state which added external additives, such as an agent.
Various external additives may be used in combination.
The total addition amount of these external additives is preferably 0.05 to 5 parts by mass, more preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the toner particles.
As the external additive mixing device, a mechanical mixing device such as a Henschel mixer or a coffee mill can be used.

According to the toner manufacturing method as described above, it is possible to reliably manufacture toner using toner particles in which the wax domain phase 15 is finely dispersed.
This is because the seed polymer resin fine particles (S) are produced in an aqueous medium so that the polyester polymer segment containing the styrene acrylic resin (A) and constituting the styrene acrylic modified amorphous polyester resin is oriented on the surface. In addition, it is possible to obtain a small-diameter product, and because the SP value difference between the release agent and the styrene acrylic resin (A) is smaller than the SP value difference between the amorphous polyester resin, the seed polymer resin fine particles (S ) Is high in affinity between the styrene acrylic resin (A) and the release agent fine particles, and when the seed polymerization resin fine particles (S) and the release agent fine particles are aggregated, This is thought to be due to the ability to inhibit coalescence.

(Developer)
The toner of the present invention can be used as a magnetic or non-magnetic one-component developer, but may be mixed with a carrier and used as a two-component developer. When the toner is used as a two-component developer, the carrier includes magnetic particles made of conventionally known materials such as metals such as iron, ferrite and magnetite, and alloys of these metals with metals such as aluminum and lead. In particular, it is preferable to use ferrite particles. Further, as the carrier, a coated carrier in which the surface of magnetic particles is coated with a coating agent such as a resin, a dispersion type carrier in which a magnetic fine powder is dispersed in a binder resin, or the like may be used.
The volume-based median diameter of the carrier is preferably 15 to 100 μm, more preferably 25 to 80 μm. The volume-based median diameter of the carrier can be typically measured by a laser diffraction particle size distribution measuring apparatus “HELOS” (manufactured by SYMPATEC) equipped with a wet disperser.

  Preferred carriers include a resin-coated carrier in which the surface of magnetic particles is coated with a resin, and a so-called resin-dispersed carrier in which magnetic particles are dispersed in a resin. The resin constituting the resin-coated carrier is not particularly limited, and examples thereof include olefin resins, styrene resins, styrene acrylic resins, acrylic resins, silicone resins, ester resins, and fluorine-containing polymer resins. . The resin constituting the resin-dispersed carrier is not particularly limited, and known resins can be used. For example, acrylic resins, styrene acrylic resins, polyester resins, fluorine resins, phenol resins, etc. are used. Can do.

[Image forming apparatus]
The toner of the present invention can be used in a general electrophotographic image forming method. As an image forming apparatus in which such an image forming method is performed, for example, a photosensitive member that is an electrostatic latent image carrier, A charging means for applying a uniform potential to the surface of the photoconductor by corona discharge having the same polarity as that of the toner, and an electrostatic latent image by performing image exposure on the surface of the uniformly charged photoconductor based on image data. An exposure means for forming an image; a developing means for conveying the toner to the surface of the photoreceptor to visualize the electrostatic latent image to form a toner image; and passing the toner image through an intermediate transfer member as necessary. For example, a transfer unit that transfers to a recording material and a fixing unit that heat-fixes the toner image on the recording material can be used.
The toner of the present invention can be suitably used at a relatively low temperature where the fixing temperature (the surface temperature of the fixing member) is 100 to 200 ° C.

  As mentioned above, although embodiment of this invention was described concretely, embodiment of this invention is not limited to said example, A various change can be added.

  Hereinafter, specific examples of the present invention will be described, but the present invention is not limited thereto.

[Preparation Example of Resin Fine Particle Dispersion MD1: Amorphous Polyester Resin Fine Particles]
(1) Synthesis of amorphous polyester resin In a reaction vessel equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple,
Bisphenol A propylene oxide 2-mole adduct 500 parts by mass Terephthalic acid 117 parts by mass Fumaric acid 82 parts by mass Esterification catalyst (tin octylate) 2 parts by mass, subjected to a condensation polymerization reaction at 230 ° C. for 8 hours, and cooled, Amorphous polyester resin [M1] was obtained.

(2) Preparation of Amorphous Polyester Resin Fine Particle Dispersion 100 parts by mass of the obtained amorphous polyester resin [M1] was pulverized with a crusher “Landel mill type: RM-2” (manufactured by Tokuju Kogakusha Co., Ltd.). The mixture was mixed with 638 parts by mass of a sodium lauryl sulfate solution having a concentration of 0.26% by mass prepared in advance and stirred for 30 minutes at V-LEVEL, 300 μA using an ultrasonic homogenizer “US-150T” (manufactured by Nippon Seiki Seisakusho). by ultrasonic dispersion, the median diameter (D ₅₀₎ of the volumetric basis is to prepare a dispersion of non-crystalline polyester resin particles [M1] [MD1] is 200 nm.

[Preparation Example of Seed Polymerization Resin Fine Particle Dispersion SD1: Seed Polymerization Resin Fine Particle Containing Styrene Acrylic Modified Polyester Resin and Styrene Acrylic Resin]
(1) Synthesis of styrene acrylic modified polyester resin In a four-necked flask with a capacity of 10 liters equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple,
Bisphenol A propylene oxide 2-mole adduct 500 parts by mass Terephthalic acid 117 parts by mass Fumaric acid 82 parts by mass Esterification catalyst (tin octylate) 2 parts by mass were added and subjected to a polycondensation reaction at 230 ° C. for 8 hours. After reacting for hours and cooling to 160 ° C,
Acrylic acid 10 parts by weight Styrene 35 parts by weight Butyl acrylate 19 parts by weight Polymerization initiator (di-t-butyl peroxide) 10 parts by weight of the mixture was dropped with a dropping funnel over 1 hour, and maintained at 160 ° C. after dropping. Then, after continuing the addition polymerization reaction for 1 hour, the temperature was raised to 200 ° C. and held at 10 kPa for 1 hour, and then acrylic acid, styrene and butyl acrylate were removed to obtain a styrene acrylic modified polyester resin [B1]. Obtained.
This styrene acrylic modified polyester resin [B1] had a glass transition point of 55 ° C. and a softening point of 99 ° C.

(2) Preparation of dispersion of styrene-acrylic modified polyester resin fine particles 100 parts by mass of the obtained styrene-acrylic modified polyester resin [B1] was pulverized with a crusher “Landel mill type: RM” (manufactured by Tokuju Kogakusha Co., Ltd.) The mixture was mixed with 638 parts by mass of the prepared sodium lauryl sulfate solution having a concentration of 0.55% by mass and stirred with an ultrasonic homogenizer “US-150T” (manufactured by Nippon Seiki Seisakusho Co., Ltd.) at V-LEVEL, 300 μA for 30 minutes. By dispersion, a dispersion “BD1” of styrene acrylic modified polyester resin fine particles [B1] having a volume-based median diameter (D ₅₀ ) of 100 nm was prepared.

(3) Seed polymerization In a 5 L reaction vessel equipped with a stirrer, a temperature sensor, a cooling pipe and a nitrogen introducing device, 540 parts by mass of a dispersion [BD1] of styrene acrylic modified polyester resin fine particles [B1] and 3000 parts of ion-exchanged water And under a temperature condition of 80 ° C.
Styrene 350 parts by mass Butyl acrylate 190 parts by mass n-octyl mercaptan 8.2 parts by mass Di-t-butylperoxyhexahydroterephthalate A polymerizable monomer mixture composed of 10 parts by mass was added dropwise over 2 hours, and then 80 ° C. Then, seed polymerization was performed by heating and stirring for 2 hours, and after the polymerization was completed, a dispersion liquid [SD1] of seed polymerization resin fine particles [S1] was prepared by cooling to 28 ° C.

[Preparation Example CD1 of Crystalline Polyester Resin Fine Particle Dispersion]
(1) Synthesis of crystalline polyester resin In a 5 L reaction vessel equipped with a stirrer, a temperature sensor, a cooling pipe and a nitrogen introducing device, 300 parts by mass of a polycarboxylic acid compound: sebacic acid (molecular weight 202.25), Monohydric alcohol compound: 170 parts by mass of 1,6-hexanediol (molecular weight 118.17) was charged, and the internal temperature was raised to 190 ° C. over 1 hour while stirring this system, and the mixture was uniformly stirred Then, Ti (OBu) ₄ was added as a catalyst in an amount of 0.003% by mass based on the charged amount of the polyvalent carboxylic acid compound. Thereafter, the internal temperature is raised from 190 ° C. to 240 ° C. over 6 hours while distilling off the generated water, and the dehydration condensation reaction is continued over 6 hours under the condition of a temperature of 240 ° C. for polymerization. As a result, a crystalline polyester resin [C1] was obtained.
The obtained crystalline polyester resin [C1] had a melting point (Tm) of 83 ° C. and a number average molecular weight of 6,300.

(2) Preparation of Dispersion of Crystalline Polyester Resin Fine Particles 30 parts by mass of crystalline polyester resin [C1] is melted and left in the molten state for each emulsion disperser “Cavitron CD1010” (manufactured by Eurotech Co., Ltd.). It was transferred at a transfer rate of 100 parts by weight per minute. Simultaneously with the transfer of the crystalline polyester resin [C1] in the molten state, 70 mass parts of reagent ammonia water was diluted with ion-exchanged water in an aqueous solvent tank with respect to the emulsification disperser, and the concentration was 0.37 mass%. The diluted ammonia water was transferred at a transfer rate of 0.1 liter per minute while being heated to 100 ° C. with a heat exchanger. Then, by operating this emulsification disperser under the conditions of a rotor rotation speed of 60 Hz and a pressure of 5 kg / cm ² , a crystalline polyester resin [C1 having a volume-based median diameter of 200 nm and a solid content of 30 parts by mass. A dispersion of fine particles [CD1] was prepared.

[Preparation Example W of Release Agent Fine Particle Dispersion]
In a reaction vessel equipped with a stirrer, a heating / cooling device, a cooling pipe and a thermometer, 11 parts by mass of paraffin wax “HNP-9” (maximum heat of fusion peak temperature: 73 ° C., manufactured by Nippon Seiwa Co., Ltd.) and 33 parts by mass of ethyl acetate The mixture was heated to 78 ° C. with stirring, stirred at the same temperature for 30 minutes, cooled to 30 ° C. over 1 hour to crystallize the paraffin wax into fine particles, and Ultraviscomil (manufactured by IMEX). ) To prepare a dispersion [W] of release agent fine particles.
The volume-based median diameter of the release agent fine particles in the dispersion liquid [W] of the release agent fine particles was measured and found to be 0.1 μm.

[Preparation Example Bk of Colorant Fine Particle Dispersion]
90 parts by mass of sodium polyoxyethylene-2-dodecyl ether sulfate was stirred and dissolved in 1510 parts by mass of ion-exchanged water. While stirring this solution, 400 parts by mass of carbon black “Regal 330” (manufactured by Cabot) is gradually added, and then dispersed using a stirrer “Claremix” (manufactured by M Technique). Thus, a dispersion of colorant fine particles [Bk] was prepared.
The volume-based median diameter of the colorant fine particles in the dispersion liquid [Bk] of the colorant fine particles was measured and found to be 110 nm.

[Toner Production Example 1: Example 1]
In a zebra flask equipped with a stirrer, a temperature sensor, a cooling tube, and a nitrogen introduction device, 2500 parts by mass of ion-exchanged water, 520 parts by mass of a dispersion of amorphous polyester resin fine particles [M1] [MD1] (solid content conversion), Dispersion liquid [SD1] of seed polymerization resin fine particles [S1] 300 parts by mass (in terms of solid content), 80 parts by mass of release agent fine particle dispersion [W] (in terms of solids), and a dispersion of colorant fine particles [ Bk] After adding 100 parts by mass and adjusting the liquid temperature to 25 ° C., an aqueous solution of sodium hydroxide having a concentration of 25% by mass was added to adjust the pH to 10.
Next, an aqueous solution in which 54.3 parts by mass of magnesium chloride hexahydrate is dissolved in 54.3 parts by mass of ion-exchanged water is added, and then the temperature of the system is raised to 87 ° C. to thereby form each resin fine particle. The agglomeration reaction between the colorant fine particles and the release agent fine particles was started.
After the start of this agglomeration reaction, sampling is performed periodically, and the volume-based median diameter of the particles is measured using a particle size distribution analyzer “Coulter Multisizer 3” (manufactured by Beckman Coulter). The mixture was agglomerated while stirring was continued until the particle size became 6 μm.
Thereafter, an aqueous solution in which 190 parts by mass of sodium chloride was dissolved in 760 parts by mass of ion-exchanged water was added to stop particle growth. Further, the temperature is raised and the mixture is heated and stirred in a state of 90 ° C. to advance the fusing of the particles, and the average circularity measurement apparatus “FPIA-2100” (manufactured by Sysmex) is used (HPF detection). When the average circularity reached 0.945, the mixture was cooled to 30 ° C. to obtain a dispersion of toner particles.
The toner particle dispersion thus obtained was subjected to solid-liquid separation using a basket-type centrifuge “MARK III Model No. 60 × 40” (manufactured by Matsumoto Kikai Co., Ltd.) to form a wet cake. This wet cake was repeatedly washed and solid-liquid separated with the basket-type centrifuge until the electric conductivity of the filtrate reached 15 μS / cm. Thereafter, a “flash jet dryer” (manufactured by Seishin Enterprise Co., Ltd.) was used, and the temperature was 40 The toner particles [1X] were obtained by spraying a stream of air at 20 ° C. and a humidity of 20% RH until the water content became 0.5% by mass and cooling to 24 ° C.
To the obtained toner particles [1X], 1% by mass of hydrophobic silica particles and 1.2% by mass of hydrophobic titanium oxide particles are added, and the condition of the peripheral speed of the rotor blades is 24 m / s using a Henschel mixer. Was added for 20 minutes, and an external additive was added by passing through a 400 mesh sieve to obtain toner [1].
It was 37 degreeC when the glass transition point was measured about the obtained toner [1].
In toner [1], the shape and particle size of the toner particles did not change with the addition of hydrophobic silica particles and hydrophobic titanium oxide particles.

[Toner Production Examples 2 to 4: Examples 2, 3 and Comparative Example 1]
Toners [2] to [4] were obtained in the same manner as in Toner Production Example 1 except that the formulation shown in Table 1 was followed.

  With respect to the toners [1] to [4], the maximum cross section of the toner particles was observed as described above, and it was observed whether or not the styrene acrylic domain phase and the wax domain phase existed adjacent to each other. The results are shown in Table 1.

[Developer Production Examples 1 to 4]
To each of toners [1] to [4], a ferrite carrier having a volume-based median diameter of 60 μm coated with a silicone resin is added so that the toner concentration becomes 6% by mass, and mixed by a V-type mixer. Thus, developers [1] to [4] were produced.

(1) Low-temperature fixability As an image forming apparatus, a commercially available full-color multi-function machine “bizhub PRO C6500” (manufactured by Konica Minolta Co., Ltd.) is used which is modified so that the surface temperature of the fixing upper bell and the fixing lower roller can be changed. Developers [1] to [4] are mounted as developers, and a solid image with a toner adhesion amount of 11.3 g / m ² is recorded on a recording material “NPi fine paper 128 g / m ² ” (manufactured by Nippon Paper Industries). The test to output at a fixing temperature of 200 ° C. and a fixing speed of 300 mm / sec was repeated until the cold offset occurred while changing the fixing temperature to decrease by 5 ° C. The surface temperature of the fixing upper belt was investigated, and this was used as the minimum fixing temperature to evaluate the low temperature fixing property. In each test, the fixing temperature is the surface temperature of the upper fixing belt, and the surface temperature of the lower fixing roller is always set to a temperature 20 ° C. lower than the upper fixing belt. The results are shown in Table 1. The lower the fixing minimum temperature, the better the low-temperature fixing property. In this invention, the case where it is 125 degrees C or less is set as a pass.

(2) Fixing Separation Using a modified “bizhub C6500” (manufactured by Konica Minolta Co., Ltd.), the recording material “Kanafuji 85 g which was left to stand overnight in a normal temperature and humidity environment (temperature 25 ° C., humidity 50% RH). / M ² T eyes ”(manufactured by Oji Paper Co., Ltd.), toner adhesion at a fixing temperature of 195 ° C. for the upper belt and 120 ° C. for the lower roller in a normal temperature and humidity environment (temperature 25 ° C., humidity 50% RH) A paper jam occurred while changing the test to output a full solid image of 4.0 g / m ² with a leading edge margin of 8 mm and reducing the leading edge margin to 7 mm, 6 mm, etc. in 1 mm increments. This process was repeated until the paper was jammed, and the minimum leading edge margin where no jamming occurred was investigated. The results are shown in Table 1. The smaller the minimum tip margin, the better the fixing separation. In this invention, it is set as a pass when it is 5 mm or less.

(3) Heat-resistant storage property After taking 0.5 g of toner in a 10-ml glass bottle with an inner diameter of 21 mm, closing the lid, and using a shaker “Tap Denser KYT-2000” (manufactured by Seishin Enterprise Co., Ltd.), after shaking 600 times at room temperature. The sample was left in an environment of a temperature of 55 ° C. and a humidity of 35% RH for 2 hours with the lid removed. Next, the toner is placed on a 48 mesh (aperture 350 μm) sieve, taking care not to break up the toner aggregates, and set in a “powder tester” (manufactured by Hosokawa Micron). After fixing and adjusting the vibration intensity to a feed width of 1 mm and applying vibration for 10 seconds, the ratio (mass%) of the toner amount remaining on the sieve was measured, and the toner aggregation rate was calculated by the following formula. This test was repeated until the toner aggregation rate exceeded 50 mass% while increasing the test temperature by 0.1 ° C. while maintaining the humidity at 35% RH. The maximum test temperature (limit heat resistant storage temperature) at which the toner aggregation rate does not exceed 50% by mass was used as an index of heat resistant storage property.
In this invention, the case where a limit heat-resistant storage temperature is 56.5 degreeC or more is set as a pass. The results are shown in Table 1.
Toner aggregation rate (mass%) = residual toner mass on sieve (g) /0.5 (g) × 100

11 Matrix phase 12 Styrene acrylic domain phase 15 Wax domain phase 18 Domain phase

Claims (2)

  Consisting of toner particles containing a binder resin having at least a polyester resin and a styrene acrylic resin, a colorant and a release agent,
  Toner particles are dispersed as a domain phase in each of a styrene acrylic resin and a release agent in a matrix phase made of a polyester resin.
  A domain phase made of styrene acrylic resin and a domain phase by a release agent are independent from each other and are slightly separated from each other without being in contact with each other. A method for producing a toner for developing a charge image, comprising:
  A method for producing a toner for developing an electrostatic charge image, comprising at least the following steps (1) and (2):
  (1) In an aqueous medium in which fine particles of a styrene acrylic modified polyester resin formed by bonding a polyester polymerization segment and a styrene acrylic polymerization segment are dispersed, a styrene monomer, a (meth) acrylic acid ester monomer, and By adding an oil-soluble polymerization initiator and performing seed polymerization with the styrene monomer and the (meth) acrylate monomer using the fine particles of the styrene acrylic modified polyester resin as seed particles, A step of producing seed polymer resin fine particles containing a styrene acrylic resin formed by polymerizing a monomer and a (meth) acrylic acid ester monomer and having the polyester polymer segment oriented on the surface
  (2) A step of agglomerating and fusing the seed polymer resin fine particles, the release agent fine particles, and the colorant fine particles in an aqueous medium to form toner particles. The polyester resin is an amorphous polyester resin;
The method for producing a toner for developing an electrostatic charge image according to claim 1, further comprising a crystalline polyester resin.

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