JP6079482B2 - Method for producing toner for developing electrostatic image - Google Patents

Description

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

  Conventionally, a crystalline organic compound, particularly a crystalline polyester resin, has been included in the toner in order to achieve low-temperature fixing of an electrostatic charge image developing toner (hereinafter also simply referred to as “toner”). . For example, Patent Document 1 and Patent Document 2 disclose a block copolymer or graft copolymer in which a crystalline polyester resin and an amorphous vinyl polymer having a functional group capable of binding thereto are chemically bonded. A toner containing a coalescence as a main component is disclosed.

  However, in such a toner, the free crystalline polyester resin migrates to the surface of the toner particles due to imperfect bonding between the amorphous vinyl polymer and the crystalline polyester resin. As a result, there is a problem that the storage stability of the toner is low.

  In order to solve such a problem of low storage stability, for example, in Patent Document 3, the solubility parameter is controlled by changing the structure of a crystalline polyester resin or an amorphous resin, A technique for improving storage stability by controlling the blending ratio is disclosed.

  However, in the method of Patent Document 3, it is inevitable that the migration of crystalline polyester proceeds in a span of several months, and it cannot be said that improvement in storage stability over a long period of time has been achieved.

  For this reason, improvement in long-term storage stability has been demanded in order to eliminate the need for strict temperature control during cargo ship transportation and warehouse storage.

  Similarly, in order to solve the problem of low storage stability, for example, a seed polymerization method in which a crystalline polyester resin is used as a seed and is coated with a styrene resin has been proposed (see Patent Document 4).

JP 63-27855 A US Pat. No. 7,547,499 JP 2006-251564 A JP 2011-197659 A

  However, in the method of Patent Document 4, similarly to the method disclosed in Patent Document 3, the occurrence of migration of the crystalline polyester resin cannot be sufficiently suppressed, and the storage stability is stable over a long period of time. There is a problem that cannot be obtained.

  In this way, a crystalline resin is contained so that sufficient low-temperature fixability is ensured, while storage stability is stably obtained over a long period of time, and a temperature-controlled refrigerated container is not used. It can be said that there is still no toner that can be transported by a cargo ship and a manufacturing method thereof.

  The present invention has been made based on the above circumstances, and its purpose is to provide excellent long-term storage stability (long-term heat-resistant storage stability) while ensuring sufficient low-temperature fixability, so that it can be transported and stored in a warehouse. It is an object of the present invention to provide a method for producing a toner for developing an electrostatic charge image that does not require strict temperature control during storage.

The method for producing an electrostatic charge image developing toner of the present invention is a method for producing an electrostatic charge image developing toner comprising toner particles containing an amorphous resin, a crystalline resin and a wax,
(A) a step of emulsifying and dispersing crystalline resin fine particles in an aqueous medium to prepare a resin fine particle dispersion;
(B) a step of dissolving a wax in a vinyl monomer at a temperature equal to or higher than a melting point to prepare a monomer solution;
(C) mixing the resin fine particle dispersion and the monomer solution to form monomer droplets containing the resin fine particles;
(D) polymerizing the monomer droplets;
(E) a step of polymerizing the monomer droplets and then holding the crystalline resin and the wax at a temperature equal to or higher than the melting point to form wax layer-forming crystalline resin fine particles;
(F) a step of forming toner particles by agglomerating and fusing the wax layer-forming crystalline resin fine particles and fine particles comprising an amorphous resin;
It is characterized by performing.

  In the method for producing a toner for developing an electrostatic image according to the present invention, the crystalline resin is preferably a crystalline polyester resin.

  According to the method for producing a toner for developing an electrostatic charge image of the present invention, a crystalline resin fine particle dispersion and a solution obtained by dissolving a wax in a vinyl monomer are mixed and polymerized, and further, the melting point of the crystalline resin and the wax is higher than the melting point. By holding (annealing) at a temperature, fine particles containing a crystalline resin and having a wax (layer) at the interface between the crystalline resin (core portion) and the vinyl resin (shell portion) are obtained. Because the amorphous resin and the wax layer-forming crystalline resin fine particles are aggregated and fused, the crystalline resin is coated with a highly hydrophobic wax and the movement is restricted against the amorphous resin matrix. The crystalline resin domain can be formed without causing migration to the crystalline resin into the amorphous resin matrix. By forming such a crystalline resin domain, low temperature fixability without causing deterioration in heat-resistant storage due to a sharp Tg (glass transition temperature) drop caused by the crystalline resin being compatible with the amorphous resin matrix. Can be maintained. As a result, an electrostatic charge image developing toner that provides excellent long-term storage stability (long-term heat-resistant storage stability) while ensuring sufficient low-temperature fixability, eliminating the need for strict temperature control during transportation and storage in a warehouse. Can be obtained.

FIG. 3 is a schematic cross-sectional view showing an example of the configuration of toner particles (electrostatic image developing toner) obtained by the production method of the present invention. In the production method of the present invention, a crystalline resin fine particle dispersion and a vinyl monomer solution in which wax is dissolved are mixed, monomer droplets containing crystalline resin fine particles are formed, polymerized, and annealed to form a wax layer-forming crystal. It is drawing which represented typically a mode (outline | summary) of forming a conductive resin fine particle.

  Hereinafter, the present invention will be described in detail.

  The method for producing a toner for developing an electrostatic charge image (hereinafter also simply referred to as “toner”) of the present invention is a method for producing a toner comprising toner particles containing an amorphous resin, a crystalline resin and a wax.

<First Embodiment>
The method for producing the toner of the present invention includes:
(A) a step of emulsifying and dispersing crystalline resin fine particles in an aqueous medium to prepare a resin fine particle dispersion;
(B) a step of dissolving a wax in a vinyl monomer at a temperature equal to or higher than a melting point to prepare a monomer solution;
(C) mixing the resin fine particle dispersion and the monomer solution to form monomer droplets containing the resin fine particles;
(D) polymerizing the monomer droplets;
(E) a step of polymerizing the monomer droplets and then holding the crystalline resin and the wax at a temperature equal to or higher than the melting point to form wax layer-forming crystalline resin fine particles;
(F) a step of forming toner particles by agglomerating and fusing the wax layer-forming crystalline resin fine particles and fine particles comprising an amorphous resin;
More specifically, (G) a filtration and washing step for solid-liquid separation of the toner particles from the toner particle dispersion and removing the surfactant and the like from the toner particles;
(H) a drying step of drying the washed toner particles;
(I) an external additive addition step of adding an external additive to the dried toner particles;
It is preferable to go through.

  Hereinafter, the wax that forms the wax layer forming crystalline resin fine particles together with the crystalline resin is referred to as “layer forming wax”.

[Configuration of toner particles]
Hereinafter, it demonstrates using drawing. FIG. 1 is a schematic cross-sectional view showing an example of the configuration of toner particles (toner for developing an electrostatic image) obtained by the production method of the present invention. FIG. 2 shows a production method of the present invention, in which a crystalline monomer fine particle dispersion and a vinyl monomer solution in which wax is dissolved are mixed, monomer droplets containing crystalline resin fine particles are formed, polymerized and annealed, It is drawing which represented typically a mode (outline | summary) of forming wax layer formation crystalline resin microparticles | fine-particles.

  By using the production method of the present invention as described above, as shown in FIG. 1, fine particles (wax layer-forming crystals) in which crystalline resin fine particles 12 made of a crystalline resin are included in a wax layer 13 made of a layer forming wax. Toner particles 11 having a structure in which (resinable resin fine particles) 15 are contained (dispersed) in an amorphous resin (matrix) 16 are obtained.

  Specifically, a core-shell type multilayer in which the crystalline resin fine particles (domains) 12 are included and the wax layer 13 is present at the interface between the crystalline resin fine particles (core portion) 12 and the vinyl resin layer (shell portion) 14. Toner particles 11 having a (matrix domain) structure in which fine particles 15 having a structure are contained (dispersed) in an amorphous resin matrix 16 are obtained. That is, the crystalline resin fine particles (domain) 12 and the amorphous resin (matrix) 16 are partitioned by the wax layer 13 and further the vinyl resin layer 14, so that the amorphous resin (matrix) 16 and the crystalline resin fine particles are separated. Toner particles 11 having a state in which (domains) 12 are phase-separated from each other are obtained.

  By using the manufacturing method of the present invention, the toner particles 11 having the matrix-domain structure shown in FIG. 1 are obtained because the crystalline resin domains are contained in the amorphous resin matrix 16 which is the main binder of the toner particles 11. 2, as shown in FIG. 2, a monomer solution 17 in which a wax 13 ′ is dissolved in a vinyl monomer 14 ′ is used on the surface of the crystalline resin fine particles 12, and polymerization (seed polymerization or the like; step (D )) And annealing (step (E)) to form the wax layer 13 and further the vinyl resin layer 14, the wax-containing resin layers 13 and 14 are also formed into the block layer in the amorphous resin matrix 16. And the migration (substance transfer) of the crystalline resin fine particles 12 to the amorphous resin matrix 16 can be prevented. The polymerization (step (D)) and annealing (step (E)) are performed at a temperature equal to or higher than the melting point of the crystalline resin and the wax, but the wax is pushed out to the outside due to the low viscosity of the wax relative to the crystalline resin. This is considered to form a structure in which the wax (layer) 13 exists at the interface between the crystalline resin fine particles 12 and the vinyl resin layer 14 made of crystalline resin. From the above viewpoint, it is desirable that the viscosity of the wax (for layer formation) is lower than that of the crystalline resin.

  Here, the fine particles (wax layer-forming crystalline resin fine particles) 15 have a degree of compatibility between the crystalline resin fine particles (domains) 12 and the amorphous resin (matrix) 16 when subjected to a thermal history as described later. The wax layer 13 preferably has a form in which the crystalline resin fine particles 12 are completely covered from the viewpoint of surely obtaining an effect of suppressing the particle size to be small. However, a part of the crystalline resin fine particles 12 is covered. Since it is considered that the effect of suppressing the above-mentioned compatibility can be obtained to some extent even in the form, it may have such a form. In other words, fine particles (wax layer-forming crystalline resin fine particles) 15 having a core-shell type multilayer structure enclose crystalline resin fine particles (domains) 12, and the crystalline resin fine particles (core portion) 12 and vinyl resin. It is preferable to have a form in which the wax layer 13 exists in the entire interface (entire area) of the layer (shell part) 14, but the above-described compatibility can be suppressed even in a form in which the wax layer 13 exists in a part of the interface. Since it can be considered that the effect is obtained to some extent, it can be said that it may have such a form.

  The structure of the toner particles 11 can be confirmed using a known means such as a transmission electron microscope (TEM). Specifically, first, the toner is embedded in a photo-curing resin and subjected to a dyeing treatment as necessary. This can be confirmed by preparing a thin section and taking a cross-sectional photograph at a magnification of 10,000 times with a transmission electron microscope (TEM) “2000FX” (manufactured by JEOL Ltd.).

  In the manufacturing method described above, the reason why the fine particles (wax layer-forming crystalline resin fine particles) 15 in which the crystalline resin fine particles 12 are included in the wax layer 13 is formed is considered as follows.

  That is, inside the fine particles (wax layer-forming crystalline resin fine particles) 15, it is considered that the phase due to the crystalline resin and the phase due to the layer forming wax each form a fine domain and are phase-separated. In the annealing step (step (E)), the fine particles 15 are maintained at a temperature equal to or higher than the melting point of the crystalline resin and the wax, so that the crystalline resin having a relatively high melt viscosity is formed in the fine particles 15. As a result of forming the crystalline resin fine particles 12 by moving to gather in the center while extruding the resin, the layer forming wax remains on the outer shell side of the fine particles 15 in a state of including the crystalline resin fine particles 12, thereby It is estimated that the wax layer 13 is formed. From the above, it is desirable that the crystalline resin has a higher melt viscosity than the wax (for layer formation).

  Therefore, in the toner of the present invention as described above, since the crystalline resin having a low glass transition point (component of the crystalline resin fine particles 12) does not migrate (substance transfer) to the surface of the toner particles 11, the low-temperature fixability is reduced. In this state, long-term storage stability can be obtained. In addition, since the degree of compatibility between the crystalline resin and the amorphous resin in the toner manufacturing process is suppressed to a small level, the heating conditions (aggregation / fusion temperature conditions in step (F)) vary in the toner manufacturing process. In such a case, since the fluctuation of the glass transition point due to the compatibility between the crystalline resin and the amorphous resin is suppressed, excellent production stability can be obtained.

Step (A): Crystalline resin fine particle dispersion preparation step In this step (A), crystalline resin fine particles are emulsified and dispersed in an aqueous medium to prepare a crystalline resin fine particle dispersion.

  In this step (A), it is preferable to gradually add the crystalline resin solution to the aqueous medium, but by performing a phase inversion emulsification method in which the aqueous medium is gradually added to the crystalline resin solution. Also good.

  As a specific procedure, first, a crystalline resin solution is prepared. Next, after heating the aqueous medium to a predetermined temperature, the crystalline resin solution is added to the aqueous medium, or after heating the aqueous medium to a predetermined temperature, the crystalline resin is dissolved. It is preferable to add an aqueous medium to the liquid. Thereby, an emulsion is prepared. Thereafter, an aqueous medium is further added to the obtained emulsion as necessary, heated to a predetermined temperature, and reduced in pressure to remove (evaporate) the organic solvent used in the crystalline resin solution, Furthermore, by returning to normal pressure and cooling, a crystalline resin fine particle dispersion can be obtained. Further, if necessary, an aqueous medium may be added in order to adjust the solid content concentration in the crystalline resin fine particle dispersion.

(Preparation method of crystalline resin solution)
The method for preparing the crystalline resin solution is not particularly limited, and the crystalline resin and the organic solvent are put into a container having an appropriate stirring and mixing means, and a predetermined temperature, preferably the melting point of the crystalline resin. While maintaining the above temperature, the crystalline resin can be dissolved in an organic solvent while stirring and mixing.

(Crystalline resin)
Crystalline resin used for preparation of crystalline resin solution in this step (A) (that is, crystalline resin which is a constituent of crystalline resin fine particles 12 contained in toner particles 11 constituting the toner of the present invention) The melting point of is preferably 40 to 100 ° C, more preferably 56 to 75 ° C. When the melting point of the crystalline resin is within the above range, sufficient low-temperature fixability and excellent storage stability can be obtained.

  Here, the melting point of the crystalline resin is specifically the first temperature that is raised from 0 ° C. to 200 ° C. at a rising / lowering speed of 10 ° C./min using a differential scanning calorimeter “Diamond DSC” (manufactured by PerkinElmer). Measurement conditions for passing through a temperature raising process, a cooling process for cooling from 200 ° C. to 0 ° C. at a cooling rate of 10 ° C./min, and a second temperature raising process for raising 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, the endothermic peak top temperature derived from the crystalline resin in the first temperature raising process is taken as the melting point. . As a measurement procedure, 3.0 mg of crystalline resin is sealed in an aluminum pan and set in a diamond DSC sample holder. The reference used an empty aluminum pan.

  Moreover, the weight average molecular weight measured by gel permeation chromatography (GPC) of the crystalline resin is preferably 7,000 to 30,000 from the viewpoint of achieving both low-temperature fixability and heat-resistant storage stability. Preferably it is the range of 10,000-25,000.

  For the measurement of the weight average molecular weight and peak molecular weight by gel permeation chromatography (GPC), specifically, an apparatus “HLC-8220” (manufactured by Tosoh Corporation) and a column “TSKguardcolumn + TSKgelSuperHZ-M3 series” (manufactured by Tosoh Corporation) While maintaining the column temperature at 40 ° C., tetrahydrofuran (THF) as a carrier solvent was allowed to flow at a flow rate of 0.2 ml / min, and the measurement sample was treated at room temperature for 5 minutes using an ultrasonic disperser at a concentration of 1 mg. / Ml, and then treated with a membrane filter having a pore size of 0.2 μm to obtain a sample solution. 10 μL of this sample solution is injected into the apparatus together with the carrier solvent, and a refractive index detector ( Detect and measure using RI detector The molecular weight distribution of the sample is calculated using a calibration curve measured using monodisperse polystyrene standard particles. Ten polystyrenes were used for calibration curve measurement.

  The peak molecular weight of the crystalline resin is preferably 3,000 to 32,000, more preferably 3,200 to 14,000.

  When the crystalline resin has a peak molecular weight within the above range, a high melt viscosity can be obtained for the crystalline resin compared to the layer-forming wax, which ensures compatibility between the crystalline resin and the amorphous resin. The wax layer 13 effective for the suppression effect can be formed. That is, if the peak molecular weight of the crystalline resin is within the range of 3,000 to 32,000, the compatibility between the crystalline resin and the amorphous resin can be sufficiently suppressed. For this reason, the obtained toner has excellent heat-resistant storage properties and sufficient low-temperature fixability. This is because the crystalline resin can be sufficiently assembled at the center in the step (E) (annealing step), and the obtained wax layer 13 can suppress the compatibility between the crystalline resin and the amorphous resin. This is presumed to be effective for the effect.

  In the toner particles 11 constituting the toner of the present invention, the crystalline resin is used in combination with a binder resin (binder resin) made of the amorphous resin 16, but can be compatible with the amorphous resin. However, depending on the toner manufacturing method, a phase-separated region can be formed, and has a function of quickly reducing the melt viscosity of the toner at the time of heat fixing. On the other hand, it is clearly phase-separated from the mold release agent and essentially does not function as a mold release agent.

  The peak molecular weight is obtained from a molecular weight distribution based on a styrene-converted molecular weight measured by gel permeation chromatography (GPC), and the peak molecular weight is a molecular weight corresponding to the elution time of the peak top in the molecular weight distribution. When there are a plurality of peak tops in the molecular weight distribution, the molecular weight corresponds to the elution time of the peak top having the largest peak area ratio.

  Examples of the crystalline resin include a crystalline polyester resin, a crystalline polyurethane resin, a crystalline polyurea resin, a crystalline polyamide resin, and a crystalline polyether resin. In particular, it is preferable to use a crystalline polyester resin.

  In the present invention, the crystalline resin means a resin having a clear endothermic peak in a DSC curve measured using the above-mentioned differential scanning calorimeter “Diamond DSC” (manufactured by PerkinElmer).

(Crystalline polyester resin)
The crystalline polyester resin suitable as the crystalline resin is preferably a polycondensate of a divalent alcohol component (diol component) and a divalent carboxylic acid component (dicarboxylic acid component). A lactone ring-opening polymer or polyhydroxycarboxylic acid can also be used.

(Diol component)
As a diol component for obtaining a crystalline polyester resin, an aliphatic diol is preferably used because of its high crystallinity and excellent heat-resistant storage stability, and an aliphatic diol having 2 to 12 carbon atoms is particularly preferable. Moreover, it is preferable to use a linear aliphatic diol. A branched aliphatic diol or an alicyclic aliphatic diol can also be used.

  Examples of the linear aliphatic diol 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-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1, Examples thereof include 18-octadecanediol and 1,2-eicosanediol. Among these, it is preferable to use ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol, and 1,10-decanediol.

  As the diol component for obtaining the crystalline polyester resin, other diols can be used as required in addition to the above.

  Other diols include carbon such as 1,2-propylene glycol, butanediol, hexanediol, octanediol, decanediol, dodecanediol, tetradecandiol, neopentyl glycol, 2,2-diethyl-1,3-propanediol A branched aliphatic diol having 2 to 12 carbon atoms; an alicyclic diol having 4 to 12 carbon atoms such as 1,4-cyclohexanedimethanol and 1,4-adamantyldimethanol; ethylene oxide (EO) of these alicyclic diols ) Adducts, propylene oxide (PO) adducts, alkylene oxide (AO) adducts such as butylene oxide (BO) adducts (addition moles 1 to 3); polylactone diols such as poly-ε-caprolactone diol; polybutadiene diols Etc.

(Dicarboxylic acid component)
As the dicarboxylic acid component for obtaining a crystalline polyester resin, it is preferable to use an aliphatic dicarboxylic acid, and it is particularly preferable to use a linear aliphatic dicarboxylic acid.

  Examples of the aliphatic dicarboxylic acid include alkane dicarboxylic acids having 4 to 12 carbon atoms such as succinic acid, adipic acid, sebacic acid, azelaic acid and dodecanedicarboxylic acid; and 4 to 6 carbon atoms such as maleic acid, fumaric acid and citraconic acid. Alkene dicarboxylic acid and the like can be mentioned.

  Among these, it is preferable to use an aliphatic dicarboxylic acid, in particular, a linear aliphatic dicarboxylic acid alone. As the linear aliphatic dicarboxylic acid, adipic acid, from the viewpoint of crystallinity of the crystalline resin, It is preferable to use sebacic acid or dodecanedicarboxylic acid. When using an aromatic dicarboxylic acid together with an aliphatic dicarboxylic acid, it is preferable to use terephthalic acid or isophthalic acid.

(Lactone)
Examples of lactones for obtaining crystalline polyester resins include monolactone rings having 3 to 12 carbon atoms such as β-propiolactone, γ-butyrolactone, δ-valerolactone, and ε-caprolactone (one ester group in the ring). ) And the like. From the viewpoint of crystallinity of the crystalline resin, it is preferable to use ε-caprolactone.

  Specifically, a ring-opening polymer of lactone is obtained by ring-opening polymerization using the above lactone as a catalyst with metal oxides, organotin compounds such as organotin compounds, organotitanium compounds, and organotin halide compounds. Can be obtained by doing. The addition amount of the catalyst is usually 0.1 to 5,000 ppm. Moreover, reaction temperature shall be 100-230 degreeC. The ring-opening polymerization of the lactone is preferably performed in an inert atmosphere.

  The ring-opening polymer of lactone may have a hydroxyl group at the terminal, and such ring-opening polymer uses glycols such as ethylene glycol and propylene glycol as a polymerization initiator for ring-opening polymerization. Obtained by. Moreover, you may have a carboxyl group at the terminal.

(Polyhydroxycarboxylic acid)
The polyhydroxycarboxylic acid constituting the crystalline polyester resin can be obtained by directly dehydrating and condensing hydroxycarboxylic acids such as glycolic acid and lactic acid (D-form, L-form, racemic form). However, a cyclic ester having 4 to 12 carbon atoms corresponding to a bimolecular or trimolecular dehydration condensate of a hydroxycarboxylic acid such as glycolide or lactide (D-form, L-form, racemate) (number of esters in the ring is 2 to 2). It is preferable from the viewpoint of controllability of the molecular weight of the crystalline polyester resin that a ring-opening polymerization method using a catalyst such as a metal oxide or an organometallic compound is used.

  From the viewpoint of adjusting the crystallinity of the crystalline polyester resin, it is preferable to use L-lactide and D-lactide.

(Crystalline polyurethane resin)
The crystalline polyurethane resin is preferably synthesized from a diol component and a diisocyanate component.

  As the diol component for obtaining the crystalline polyurethane resin, the same diol component as described above can be used.

(Diisocyanate component)
Examples of the diisocyanate component for obtaining the crystalline polyurethane resin include aromatic diisocyanates having 6 to 20 carbon atoms (excluding carbon in the NCO group), aliphatic diisocyanates having 2 to 18 carbon atoms, and fats having 4 to 15 carbon atoms. Examples thereof include cyclic diisocyanates, araliphatic diisocyanates having 8 to 15 carbon atoms, and modified products of these diisocyanates. These may be used alone or in combination of two or more.

  As a diisocyanate component for obtaining a crystalline polyurethane resin, a triisocyanate or higher polyisocyanate may be used together with the diisocyanate.

  Aromatic diisocyanates include 1,3- and / or 1,4-phenylene diisocyanate, 2,4- and / or 2,6-tolylene diisocyanate (TDI), 2,4′- and / or 4,4 ′. -Diphenylmethane diisocyanate (MDI), polyallyl polyisocyanate (PAPI), 1,5-naphthylene diisocyanate, 4,4 ', 4 "-triphenylmethane triisocyanate, m- and p-isocyanatophenylsulfonyl isocyanate It is done.

  Aliphatic diisocyanates include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodemethylene diisocyanate, 1,6,11-undecane diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2, Examples include 6-diisocyanatomethyl caproate, bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate, 2-isocyanatoethyl-2,6-dicyanatohexanoate.

  Examples of alicyclic diisocyanates include isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4′-diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), and bis (2-isocyanatoethyl). Examples include -4-cyclohexene-1,2-dicarboxylate, 2,5- and / or 2,6-norbornane diisocyanate.

  Examples of the araliphatic diisocyanate include m- and / or p-xylylene diisocyanate (XDI), α, α, α ', α'-tetramethylxylylene diisocyanate.

  Examples of the modified product of diisocyanate include modified products of urethane group, carbodiimide group, allophanate group, urea group, burette group, uretdione group, uresiimine group, isocyanurate group, and oxazolidone group. Specific examples include urethane-modified MDI, urethane-modified TDI, carbodiimide-modified MDI, and trihydrocarbyl phosphate-modified MDI. These can be used alone or in combination of two or more.

  Among these, it is preferable to use an aromatic diisocyanate having 6 to 15 carbon atoms, an aliphatic diisocyanate having 4 to 12 carbon atoms, and an alicyclic diisocyanate having 4 to 15 carbon atoms, particularly preferably TDI, MDI, HDI, water. They are MDI and IPDI.

[Crystalline polyamide resin]
The crystalline polyamide resin is preferably obtained from a reaction between a diamine component and a dicarboxylic acid component.

  As the dicarboxylic acid component for obtaining the crystalline polyamide resin, the same ones as described above can be used.

(Diamine component)
As a diamine component and a polyamine component for obtaining a crystalline polyamide resin, an aliphatic diamine or an aliphatic polyamine is preferably used, and an aromatic diamine can also be used.

  Examples of the aliphatic diamine and aliphatic polyamine include the following.

(1) Linear aliphatic diamines One having 2 to 6 carbon atoms such as ethylenediamine, propylenediamine, trimethylenecyamine, tetramethylenediamine, hexamethylenediamine.

(2) Aliphatic polyamines having 2 to 6 carbon atoms such as diethylenetriamine, iminobispropylamine, bis (hexamethylene) triamine, triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine.

(3) Branched aliphatic diamine dialkyl (1 to 3 carbon atoms) aminopropylamine, trimethylhexamethylenediamine, aminoethylethanolamine, 2,5-dimethyl-2,5-hexamethylenediamine, methyliminobispropylamine.

(4) Alicyclic diamines having 4 to 15 carbon atoms such as 1,3-diaminocyclohexane, isophoronediamine, mensendiamine, 4,4′-methylenedicyclohexanediamine (hydrogenated melendiamine).

(5) Heterocyclic diamine piperazine, 4-aminoethylpiperazine, 1,4-diaminoethylpiperazine, 1,4-bis (2-amino-2-methylpropyl) piperazine, 3,9-bis (3-aminopropyl) ) Those having 4 to 15 carbon atoms such as -2,4,8,10-tetraoxaspiro [5,5] undecane.

(6) Aromatic ring-containing aliphatic diamines having 8 to 15 carbon atoms such as xylylenediamine and tetrachloro-p-xylylenediamine.

  Examples of the aromatic diamine that can be used in combination with the aliphatic diamine and the aliphatic polyamine include those having 6 to 20 carbon atoms. Specifically, the following are preferably used.

(7) unsubstituted aromatic diamine 1,2-, 1,3- and 1,4-phenylenediamine, 2,4′- and 4,4′-diphenylmethanediamine, polyphenylpolymethylenepolyamine, diaminodiphenylsulfone, Thiodianiline, bis (3,4-diaminophenyl) sulfone, 2,6-diaminopyridine, m-aminobenzylamine, triphenylmethane-4,4 ′, 4 ″ -triamine, naphthylenediamine and the like.

(8) Aromatic diamines substituted with an alkyl group having 1 to 4 carbon atoms 2,4-tolylenediamine, 2,6-tolylenediamine, ethyltolylenediamine, 4,4'-diamino-3,3 '-Dimethyldiphenylmethane, 4,4'-bis (o-toluidine), dianisidine, diaminoditolyl sulfone, 1,3-dimethyl-2,4-diaminobenzene, 1,4-diisopropyl-2,5-diaminobenzene, 2,4-diaminobenzene, 1-methyl-3,5-diethyl-2,4,3,3 ′, 5.5′-tetramethylbenzidine, 3,3 ′, 5,5′-tetramethyl 4,4 '-Dimethyldiphenylmethane, 3,5-diethyl-3'-methyl-2', 4-diaminodiphenylmethane, 3,3'-diethyl-2.2'-aminodiphenylmethane, 4,4'-diamino-3 3′-dimethyldiphenylmethane, 3,3 ′, 5,5′-tetraethyl-4,4′-diaminobenzophenone, 3,3 ′, 5,5′-tetraethyl-4,4′-diaminodiphenyl ether, 3,3 ′ , 5,5'-tetraisopropyl-4,4'-diaminodiphenyl sulfone and mixtures of these isomers.

A part or all of the amino groups of the aromatic diamines of the above (7) to (8) are substituted with —NH—R ¹ (wherein R ¹ is a lower alkyl group such as a methyl group or an ethyl group), 4 , 4′-di (methylamino) diphenylmethane, 1-methyl-2-methylamino-4-aminobenzene, and the like.

  Moreover, as a polyamine component for obtaining a crystalline polyamide resin, the following other polyamine components can also be used.

(9) Other polyamines Low molecular weight polyamide polyamines obtained by condensation of dicarboxylic acids such as dimer acids and excess aliphatic polyamines (more than 2 moles per mole of dicarboxylic acid), cyanoethyl polyols such as polyalkylene glycols Polyether polyamines such as hydrides.

(Crystalline polyurea resin)
The crystalline polyurea resin is preferably obtained from a reaction between a diamine component and a diisocyanate component.

  As the diamine component and polyamine component for obtaining the crystalline polyurea resin, the same ones as described above can be used.

  Moreover, as a diisocyanate component for obtaining crystalline polyurea resin, the same thing as the above-mentioned can be used.

[Crystalline polyether resin]
As the crystalline polyether resin, a crystalline polyoxyalkylene polyol or the like can be used.

  Examples of the alkylene oxide (AO) used for the production of the crystalline polyoxyalkylene polyol include those having 3 to 9 carbon atoms.

  Specifically, examples of the alkylene oxide (AO) having 3 carbon atoms include propylene oxide, 1-chlorooctacene, 1,2-dichlorooctacene, epichlorohydrin, epibromohydrin, and the like.

  Examples of the alkylene oxide (AO) having 4 carbon atoms include 1,2-butylene oxide and methyl glycidyl ether.

  Examples of the alkylene oxide (AO) having 5 carbon atoms include 1,2-pentylene oxide, 2,3-pentylene oxide, 3-methyl-1,2-butylene oxide, and the like.

  Examples of the alkylene oxide (AO) having 6 carbon atoms include cyclohexene oxide, 1,2-hexylene oxide, 2,3-hexylene oxide, 3-methyl-1,2-pentylene oxide, 4-methyl-2,3 -Pentylene oxide, allyl glycidyl ether, etc. are mentioned.

  Examples of the alkylene oxide (AO) having 7 carbon atoms include 1,2-hexylene oxide.

  Styrene oxide is mentioned as a C8 alkylene oxide (AO).

  Examples of the alkylene oxide (AO) having 9 carbon atoms include phenyl glycidyl ether.

  Among these alkylene oxides, it is preferable to use propylene oxide, 1,2-butylene oxide, styrene oxide, cyclohexene oxide, and particularly preferably propylene oxide, 1,2-butylene oxide, cyclohexene oxide, and the polymerization rate is high. Most preferred is propylene oxide because it is high. These alkylene oxides (AO) can be used alone or in combination of two or more.

  As a method for synthesizing the crystalline polyoxyalkylene polyol, various conventionally known methods can be used. Specifically, Journal of the American Chemical Society 78, 18, p. A method of ring-opening polymerization of a chiral alkylene oxide (AO) disclosed in 4787-4792 (1956) using a catalyst usually used in the polymerization of alkylene oxide (AO), disclosed in JP-A-11-12353 And a method of using as a catalyst a compound obtained by contacting a sterically bulky lanthanide complex and an organoaluminum, and reacting a bimetal μ-oxoalkoxide and a boroxyl compound disclosed in JP-T-2001-521957 in advance. Methods, Journal of the American Chemical Society 127, 33, p. 11566-11567 (2005), and a method for obtaining a polyoxyalkylene polyol having a high isocity is mentioned.

  In the method of ring-opening polymerization of a chiral alkylene oxide (AO), a polyoxyalkylene glycol having a hydroxyl group at the terminal and having an isotacticity of 50% or more can be obtained by using glycol or water as a polymerization initiator. . The end of the polyoxyalkylene glycol having an isotacticity of 50% or more may be modified with a carboxyl group. Usually, when the isotacticity is 50% or more, it becomes crystalline.

  The isotacticity is more preferably 70% or more, further preferably 80% or more, and particularly preferably 90% or more from the viewpoint of obtaining high sharp melt properties and blocking resistance.

  Isotacticity is described in Macromolecule, 35, 6, p. 2389-2392 (2002).

Specifically, 30 mg of a measurement sample was weighed into a ¹³ C-NMR sample tube having a diameter of 5 mm, and 0.5 ml of deuterated solvent (deuterated chloroform, deuterated toluene, deuterated dimethylformamide, deuterated). A solvent capable of dissolving the sample, such as dimethyl sulfoxide, is added and dissolved, and the signal derived from the methine group of the ¹³ C-NMR tripartite, syndiotactic value: around 75.1 ppm, heterotactic value: 75 .About.3 ppm, isotactic value: around 75.5 ppm can be observed and calculated from the following formula (a).

  In the above formula (a), I is an integrated value of isotactic values, S is an integrated value of syndiotactic values, and H is an integrated value of heterotactic values.

  The above crystalline resins may have a structure in which two or more of them are bonded as a block copolymer.

[Organic solvent]
The organic solvent used for the preparation of the crystalline resin solution in this step (A) may be any solvent that dissolves the crystalline resin and has a boiling point higher than the melting point of the crystalline resin, such as ethyl acetate, methyl ethyl ketone, Toluene, isopropyl alcohol and the like can be preferably used. The above-mentioned organic solvent can be used individually by 1 type or in combination of 2 or more type as needed. In particular, it is preferable to control the temperature of evaporation of the organic solvent at the time of desolvation to a range of 30 to 50 ° C. under a practical reduced pressure, more preferably to a range of 30 to 45 ° C. It is particularly preferable to use ethyl acetate.

  The temperature at which the crystalline resin is dissolved in the organic solvent may be a temperature equal to or higher than the melting point of the crystalline resin, but from the viewpoint of economy or production cost, the temperature is the same as the melting point of the crystalline resin by 5 ° C or higher. It is preferable that the temperature be 2 to 5 ° C. higher than the melting point of the crystalline resin.

  The amount of the crystalline resin used for the preparation of the crystalline resin solution in this step (A) is 10 to 60% by mass with respect to the crystalline resin solution from the viewpoint of productivity and the solubility of the resin in the solvent. It is preferable that it is in the range of 30 to 60% by mass.

  The container (apparatus) having the stirring and mixing means used for the preparation of the crystalline resin solution is not particularly limited. For example, a condenser, a thermometer, a water dropping apparatus, and a jacketed 3 liter equipped with anchor blades. Reaction tank (Tokyo Rika Kikai Co., Ltd. product: BJ-30N) etc. are mentioned.

(Preparation of emulsion)
In this step (A), it is preferable to gradually add the crystalline resin solution to the aqueous medium to prepare an emulsion, but the phase inversion gradually adds the aqueous medium to the crystalline resin solution. An emulsion may be prepared by an emulsification method.

  In the former method of preparing the emulsion, the aqueous medium is heated to a predetermined temperature, and then the crystalline resin solution heated to the predetermined temperature is added to the aqueous medium to be emulsified and dispersed. To prepare. Here, it is desirable that the temperature of the aqueous medium is the same as that of the crystalline resin solution. During the period of emulsifying and dispersing by the above procedure to prepare an emulsion, the aqueous medium is appropriately stirred and mixed. By stirring and mixing, oil droplets (micelles) in the emulsion formed by emulsification and dispersion are prepared so as to have a desired oil droplet size (= crystalline resin fine particle size). A crystalline resin fine particle dispersion having a size can be obtained. Further, it is desirable to gradually add the crystalline resin solution to the aqueous medium. Specifically, the addition (dropping) rate of the crystalline resin solution is 0.1 to 10 parts by mass / min with respect to 100 parts by mass of the aqueous medium from the viewpoint of controlling the particle size of the oil droplets as described above. Is more preferable, and more preferably in the range of 1 to 5 parts by mass / minute. In addition, in order to improve the dispersion stability of oil droplets during emulsification, it is better to add an alkali as a neutralizing agent. Specific examples include sodium hydroxide and ammonia.

  Even in the latter emulsion preparation method (phase inversion emulsification method), the aqueous medium is heated to a predetermined temperature, and then the aqueous medium is added to the crystalline resin solution heated to the predetermined temperature to emulsify and disperse. To prepare an emulsion. Here, it is desirable that the temperature of the aqueous medium is the same as that of the crystalline resin solution. During the period of emulsifying and dispersing by the above procedure to prepare an emulsion, the crystalline resin solution is appropriately mixed with stirring. By stirring and mixing, oil droplets (micelles) in the emulsion formed by emulsification and dispersion are prepared so as to have a desired oil droplet size (= crystalline resin fine particle size). A crystalline resin fine particle dispersion having a size can be obtained. Further, it is desirable to gradually add an aqueous medium to the crystalline resin solution. Specifically, the rate of addition (dropping) of the aqueous medium is 0.1 to 10 parts by mass / min with respect to 100 parts by mass of the crystalline resin solution from the viewpoint of controlling the particle size of the oil droplets as described above. Is more preferable, and more preferably in the range of 1 to 5 parts by mass / minute. In order to improve the dispersion stability of oil droplets during phase inversion emulsification, it is better to add an alkali as a neutralizing agent. Specific examples include sodium hydroxide and ammonia.

[Aqueous medium]
The “aqueous medium” used for preparing the emulsion in this step (A) 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. It is preferable to use an alcohol-based organic solvent that does not dissolve the resin.

  In addition, amine or ammonia may be dissolved in the aqueous medium as necessary.

[Surfactant]
In the above-mentioned aqueous medium, surfactants (emulsifiers) such as ordinary cationic surfactants, anionic surfactants, amphoteric surfactants, and nonionic surfactants are dissolved as necessary. Also good. As the surfactant (emulsifier), it is preferable to use an anionic surfactant because it is excellent in dispersion stability of the crystalline resin fine particles and stability against temperature change is obtained.

  Examples of the anionic surfactant include higher fatty acid salts such as sodium oleate; alkyl aryl sulfonates such as sodium dodecylbenzene sulfonate; alkyl sulfate salts such as sodium lauryl sulfate; polyethoxyethylene lauryl ether sodium sulfate Polyoxyethylene alkyl ether sulfate salts of polyoxyethylene alkylaryl ether sulfate salts such as sodium polyoxyethylene nonylphenyl ether sulfate; sodium monooctyl sulfosuccinate, sodium dioctyl sulfosuccinate, sodium polyoxyethylene lauryl sulfosuccinate, etc. Examples thereof include alkyl sulfosuccinic acid ester salts and derivatives thereof.

  The above surfactants can be used singly or in combination of two or more as desired.

  In the case of using a surfactant, the addition amount of the surfactant is preferably 0.1 to 10% by mass with respect to the crystalline resin solution from the viewpoint of dispersion stability of the crystalline resin fine particles. More preferably, it is the range of 0.5-5.0 mass%.

  In the preparation of the emulsion, the specific means for emulsifying and dispersing includes giving mechanical energy, and the dispersing device for giving mechanical energy is not particularly limited, For example, a stirrer equipped with a rotor capable of high-speed rotation, an ultrasonic dispersion device, a mechanical homogenizer, a Manton Gorin, a pressure homogenizer, or the like can be used.

  In the preparation of the emulsion, the amount of the crystalline resin solution used is preferably 10 to 50% by mass with respect to the total amount of the emulsion from the viewpoint of productivity and dispersion stability of the emulsion. Preferably it is the range of 30-50 mass%.

(Removal of organic solvent)
In this step (A), after preparing the emulsion, the organic solvent used in the crystalline resin solution is removed (evaporated) by heating to a predetermined temperature and reducing the pressure.

  Next, the temperature for distilling off (removing) the organic solvent at the time of solvent removal is preferably 30 to 50 ° C. under a practical reduced pressure, more preferably 30 from the viewpoint of maintaining the dispersion stability of the emulsion. It is the range of -45 degreeC.

  Moreover, the pressure of evaporation (removal) of the organic solvent at the time of desolvation may be under a practical reduced pressure from the viewpoint of maintaining the dispersion stability of the emulsion, and is specifically 0.4 to 50 kPa. Is more preferable, and the range of 0.5 to 50 kPa is more preferable.

  In the removal of the organic solvent described above, as a specific means for removing the organic solvent from the emulsion, an apparatus capable of separating and recovering (removing) only the organic solvent using a difference in boiling point under reduced pressure. There is no particular limitation, and for example, a device such as a rotary evaporator can be used.

(Preparation of crystalline resin fine particle dispersion)
In this step (A), the desired crystalline resin fine particle dispersion can be obtained by removing the solvent from the emulsion and then cooling it back to normal pressure. That is, by removing the organic solvent from the oil droplets in the emulsion, it is possible to obtain a dispersion in which the oil droplets are dispersed as crystalline resin fine particles composed of a crystalline resin.

  Here, as the aqueous medium added to the crystalline resin fine particle dispersion as necessary, the same “aqueous medium” used for preparing the emulsion can be used. Preferably, water (ion exchange water) is used from the viewpoint of dilution.

  In this step (A), an aqueous medium may be added to adjust the solid content concentration in the obtained crystalline resin fine particle dispersion as necessary. The solid content concentration (content of crystalline resin fine particles) in the crystalline resin fine particle dispersion finally prepared in this step (A) is 5 to 30% by mass from the viewpoint of compatibility with the toner production process. It is preferably 10 to 30% by mass, and an aqueous medium may be added as necessary. That is, a crystalline resin which is a constituent component of the crystalline resin fine particles 12 contained in the toner particles 11 constituting the toner of the present invention (a crystalline resin which is a constituent component of the crystalline resin fine particles used in this step (A)) ) Is preferably 10 to 60% by mass with respect to the total resin constituting the toner particles, from the viewpoint of obtaining sufficient low-temperature fixability and excellent storage stability.

  The particle diameter of the crystalline resin fine particles in the dispersion obtained in this step (A) is preferably, for example, 50 to 300 nm in terms of volume-based median diameter from the viewpoint of toner performance and production compatibility. Is in the range of 80-300 nm.

  The particle diameter of the crystalline resin fine particles is measured by a dynamic light scattering method using “Microtrac UPA-150” (manufactured by Nikkiso Co., Ltd.).

  Further, the particle size of the crystalline resin fine particles contained in the toner particles 11 constituting the toner of the present invention is measured using a known means such as a scanning electron microscope (SEM) or a transmission electron microscope (TEM). can do. Specifically, first, the toner is embedded in a photo-curing resin and subjected to a dyeing treatment as necessary. An average particle diameter of the crystalline resin fine particles is prepared by preparing a thin section and taking a cross-sectional photograph with a magnification of 10,000 times with a transmission electron microscope (TEM) “2000FX” (manufactured by JEOL Ltd.). Can be measured. However, it is not limited to a specific method using the above-described TEM. In the present specification, the “particle diameter” means the maximum distance among the distances between any two points on the contour line of the crystalline resin fine particles in the SEM or TEM image. As the value of “average particle diameter”, the average particle diameter of particles observed in several to several tens of fields using an observation means such as a scanning electron microscope (SEM) or a transmission electron microscope (TEM). The calculated value shall be adopted.

  The average particle diameter of the crystalline resin fine particles 12 contained in the toner particles 11 constituting the toner of the present invention is preferably 100 to 900 nm, more preferably from the viewpoint of achieving both low temperature fixability and heat resistant storage stability. Is in the range of 100-800 nm.

Step (B): Wax-containing vinyl monomer solution preparation step In this step (B), the layer-forming wax is dissolved in the vinyl monomer at a temperature equal to or higher than the melting point, and the layer-forming wax-containing vinyl monomer solution (simply also referred to as the monomer solution). ) Is prepared. In order to distinguish from the release agent (wax fine particles) dispersed in the amorphous resin (matrix), the wax used in this step is also referred to as a layer forming wax.

(Method for preparing monomer solution)
As a method for preparing the monomer solution, a vinyl monomer is put into a container having an appropriate stirring and mixing means, and a layer forming wax is added thereto, and the mixture is stirred while being maintained at a temperature equal to or higher than the melting point of the layer forming wax. It can be prepared by dissolving the layer forming wax in a vinyl monomer while mixing.

[Vinyl monomer]
As the vinyl monomer, a styrene monomer, a (meth) acrylic acid ester monomer, a (meth) acrylic acid monomer, and the like can be used. You may use these monomers individually or in mixture of 2 or more types. The vinyl monomer may be a monomer having a H 2 _{C =} CH- structure, which by no means limited to the above monomers.

  Examples of the styrene monomer include styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, α-methyl styrene, p-phenyl styrene, p-ethyl styrene, 2,4-dimethyl styrene, p-tert. -Butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene and the like.

  Examples of (meth) acrylic acid ester monomers include methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, hydroxyethyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, cyclohexyl. Methacrylate, 2-ethylhexyl methacrylate, hydroxyethyl methacrylate, isopropyl acrylate, t-butyl acrylate, n-octyl acrylate, stearyl acrylate, lauryl acrylate, phenyl acrylate, isopropyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, stearyl methacrylate, laur Examples include yl methacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, and dimethylaminoethyl methacrylate.

  Examples of the (meth) acrylic acid monomer include (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, and the like.

  The amount of the vinyl monomer used is preferably from 60 to 95% by mass, more preferably from 60 to 80% by mass, based on the monomer solution, from the viewpoint of the solubility of the wax in the monomer.

〔wax〕
Specific examples of the layer forming wax that forms crystalline resin fine particles together with the crystalline resin include, for example, low molecular weight polyethylene wax, low molecular weight polypropylene wax, Fischer-Tropsch wax, microcrystalline wax, and paraffin wax. Hydrocarbon waxes such as: carnauba wax, pentaerythritol behenate, behenyl behenate, behenyl citrate, stearyl stearate, pentaerythritol tetrabehenate, pentaerythritol tetrastearate, dipentaerythritol tetrastearin Acid ester, glycerol tribehenate, glycerol tristearate, diglycerol hexabehenate, stearyl sebacate Trimethylolpropane behenate, succinic acid distearyl glycerol 1,2 hydro stearate, glycerin monobehenate, can be used esters wax such as citric acid tristearyl. Among these, it is particularly preferable to use hydrocarbon waxes such as paraffin wax; ester waxes such as behenyl behenate and glycerin monobehenate from the viewpoint of obtaining image storage resistance.

  Since the layer forming wax has a very low melt viscosity as compared with the crystalline resin, when the layer forming wax is kept above the melting point of the layer forming wax in the step (E) (annealing step), Since the leaching of the layer forming wax to the outer shell can be sufficiently advanced, it is possible to reliably form the wax layer 13 effective for suppressing the compatibility between the crystalline resin and the amorphous resin. Yes (see FIGS. 1 and 2).

  As the layer forming wax, it is preferable to use a wax having a melting point higher by 10 to 40 ° C. than the melting point of the crystalline resin. By using a wax having a melting point higher by 10 to 40 ° C. than the melting point of the crystalline resin, it is possible to reliably form the wax layer 13 effective in suppressing the compatibility between the crystalline resin and the amorphous resin. it can.

  The amount of the layer forming wax used is preferably 5 to 40% by mass, more preferably 20 to 40% by mass, based on the monomer solution, from the viewpoint of the solubility of the wax in the monomer. Furthermore, the content of the layer forming wax constituting the wax layer 13 of the toner particles 11 constituting the toner of the present invention is the mass ratio of the toner particles 11 to the crystalline resin constituting the crystalline resin fine particles 12 and The ratio of the functional resin to the layer forming wax is preferably 9: 1 to 6: 4, more preferably 8: 2 to 7: 3. When the content of the layer forming wax is within the above range, the wax layer 13 effective for suppressing the compatibility between the crystalline resin and the amorphous resin can be reliably formed. The content of the vinyl resin (= polymer of the vinyl monomer) constituting the vinyl resin layer 14 of the toner particles 11 constituting the toner of the present invention is the same as that of the crystalline resin constituting the crystalline resin fine particles 12 of the toner particles 11. In this mass ratio, the crystalline resin: vinyl resin is preferably 9: 1 to 5: 5, more preferably 8: 2 to 6: 4. When the content of the vinyl resin is in the above range, the vinyl resin layer 14 effective for suppressing the compatibility between the crystalline resin and the amorphous resin can be reliably formed.

  The temperature at the time of preparation of the monomer solution may be a temperature equal to or higher than the melting point of the layer forming wax, but from the viewpoint of economy or production cost, the temperature is the same as the melting point of the layer forming wax at a temperature higher by 5 ° C. It is preferable that the temperature is 2 to 5 ° C. higher than the melting point of the layer forming wax.

  The vessel (apparatus) having the stirring and mixing means used for the preparation of the monomer solution is not particularly limited. For example, a jacketed 3 liter reaction vessel (Tokyo Rika Instrument Co., Ltd.) equipped with a condenser, a thermometer, and anchor blades Co., Ltd .: BJ-30N).

Step (C): Crystalline resin fine particle-containing monomer droplet forming step This step (C) is a step of the crystalline resin fine particle dispersion obtained in the step (A) and the layer obtained in the step (B). The forming wax-containing monomer solution is mixed to form monomer droplets containing the crystalline resin fine particles. In the present invention, since the monomer droplet has a lower melt viscosity than the crystalline resin, high dispersion stability can be obtained in the formed monomer droplet. Accordingly, the amorphous resin (matrix) in which the crystalline resin (domain) existing in the center of the wax layer-forming crystalline resin fine particles formed by polymerizing and annealing the monomer droplets encloses the wax layer-forming crystalline resin fine particles. It is presumed that migration (substance transfer) to the surface of the toner particles made up of) is suppressed, and as a result, excellent storage stability can be obtained.

(Method for forming monomer droplets containing crystalline resin fine particles)
In this step (C), the layer-forming wax-containing monomer solution obtained in the step (B) is gradually added to the crystalline resin fine particle dispersion obtained in the step (A) ( The former method for forming monomer droplets) is preferable, but the crystalline resin fine particle dispersion obtained in the step (A) is gradually added to the monomer solution obtained in the step (B) (the latter). (Monomer droplet formation method).

  Among these, as a specific procedure of the former method of forming monomer droplets, the crystalline resin fine particle dispersion obtained in the step (A) is placed in an apparatus (container) having appropriate heating means and stirring and mixing means. Then, an aqueous solvent is added as necessary, heated to a predetermined temperature while stirring, a polymerization initiator solution is added thereto, and the layer-forming wax-containing monomer solution obtained in the step (B) is gradually added. By adding (dropping), a monomer droplet containing the crystalline resin fine particles can be formed.

  First, in the former method of forming monomer droplets, the aqueous medium may be added in order to adjust the solid content concentration in the crystalline resin fine particle dispersion prepared in advance. Specifically, the solid content concentration (the content of the crystalline resin fine particles) in the crystalline resin fine particle dispersion is preferably 5 to 30% by mass from the viewpoint of polymerization stability, and more preferably 10 to 10% by mass. What is necessary is just to add an aqueous medium as needed so that it may become in the range of 30 mass%.

  Here, as the aqueous solvent which can be added (charged) as necessary, the same “aqueous medium” used for preparing the emulsion in the step (A) can be used. Preferably, water (ion exchange water) is used from the viewpoint of dilution.

  Next, in the former method of forming monomer droplets, the crystalline resin fine particle dispersion prepared in the apparatus (container) is heated to a predetermined temperature using the heating means. The heating temperature (dispersion temperature) is preferably a temperature equal to or higher than the melting point of the crystalline resin and the wax from the viewpoint of solubility of the crystalline resin and the wax, and is the same as the melting point of the crystalline resin and the wax. The temperature is more preferably 5 ° C., more preferably 2 to 5 ° C. higher than the melting point of the crystalline resin and the wax. Here, the melting point of the crystalline resin and the wax is equal to or higher than the higher melting point of the melting point of the crystalline resin and the melting point of the layer forming wax. Similarly, the temperature 2 to 5 ° C. higher than the melting point of the crystalline resin and the wax is a temperature 2 to 5 ° C. higher than the higher one of the melting point of the crystalline resin and the melting point of the layer forming wax. Shall be pointed to.

  As the heating means, for example, a condenser, a thermometer, a dropping device, a jacketed 3 liter reaction tank equipped with anchor blades (manufactured by Tokyo Rika Kikai Co., Ltd .: BJ-30N) and the like can be used.

  Next, in the former method for forming monomer droplets, the crystalline resin fine particle dispersion in the apparatus (container) is heated to a predetermined temperature, and then the polymerization initiator solution is added.

  The polymerization initiator is not particularly limited as long as it is a polymerization initiator used for polymerization of a vinyl monomer. For example, as an oil-soluble polymerization initiator, 2,2′-azobis- (2,4 -Dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvalero Azo or diazo polymerization initiators such as nitriles; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, t-butyl hydroperoxide, di-t-butyl peroxide, dicumyl peroxide, 2 , 4-Dichlorobenzoyl peroxide, Lauroyl peroxide , 2,2-bis- (4,4-t-butylperoxycyclohexyl) propane, peroxide-based polymerization initiators such as tris- (t-butylperoxy) triazine and polymers having a peroxide in the side chain An initiator etc. are mentioned. Examples of water-soluble polymerization initiators include persulfates such as potassium persulfate and ammonium persulfate; azobisaminodipropane acetate, azobiscyanovaleric acid and salts thereof, hydrogen peroxide, and the like. It is not limited. These may be used alone or in combination of two or more. Preferably, potassium persulfate can be suitably used.

  A solvent for dissolving the polymerization initiator for preparing the polymerization initiator solution is not particularly limited, but an aqueous solvent is preferable from the viewpoint of compatibility with the crystalline resin fine particle dispersion. As the aqueous solvent, those similar to the “aqueous medium” used for preparing the emulsion in the step (A) can be used. Preferably, it is water (ion exchange water).

  As content of the polymerization initiator in the said polymerization initiator solution, it is preferable that it is 1-10 mass%, More preferably, it is the range of 1-5 mass%.

  The addition amount of the polymerization initiator is preferably 0.1 to 5 parts by mass with respect to 100 parts by weight of the monomer contained in the monomer solution in order to complete the polymerization without residual monomer components, Preferably it is the range of 1-3 mass parts.

  Next, in the former method for forming monomer droplets, the crystalline resin fine particle dispersion in the apparatus (container) is heated to a predetermined temperature, the polymerization initiator solution is added, and then the layer obtained in the step (B). The forming wax-containing monomer solution is gradually added (dropped). Thereby, monomer droplets containing the crystalline resin fine particles can be formed.

  The addition amount of the monomer solution is preferably 20 to 400 parts by weight, more preferably 100 parts by weight of the crystalline resin contained in the crystalline resin fine particle dispersion in the apparatus (container). It is the range of 30-300 mass parts.

  The addition rate (dropping rate) of the monomer solution is 2 to 30 masses per 100 parts by mass of the crystalline resin fine particle dispersion after concentration adjustment in the apparatus (container) from the viewpoint of particle size control of the monomer oil droplets. It is preferable to set it as a part / minute, More preferably, it is the range of 10-30 mass part / minute.

  The temperature (liquid temperature) of the layer-forming wax-containing monomer solution used for addition (dropping) is also higher than the melting point of the crystalline resin and the layer-forming wax from the viewpoint of solubility of the crystalline resin and the wax. Preferably, the temperature is the same as the melting point of the crystalline resin and the layer forming wax, which is 5 ° C. higher, and more preferably 2 to 5 ° C. higher than the melting point of the crystalline resin and the layer forming wax. It is desirable to carry out at temperature.

  The average particle size of the monomer droplets containing the crystalline resin fine particles (see FIG. 2) formed by the former method for forming monomer droplets is 0.1 to 1.0 μm, preferably 0.1 to 0 μm. .8 μm. The particle size of the monomer droplets can be controlled (adjusted) by, for example, the amount of the surfactant, the stirring speed (stirring power), the addition speed of the monomer solution, and the like.

  The average particle diameter of the monomer droplets can be calculated by measuring with “Microtrac UPA-150” (manufactured by Nikkiso Co., Ltd.).

  As a specific procedure of the latter method of forming monomer droplets, the layer-containing wax-containing monomer solution obtained in the step (B) is placed in an apparatus (container) having appropriate heating means and stirring and mixing means. After charging and heating to a predetermined temperature, the monomer droplets containing the crystalline resin fine particles can be formed by adding and mixing the crystalline resin fine particle dispersion obtained in the step (A).

  First, in the latter method for forming monomer droplets, the monomer solution charged in the apparatus (container) is heated to a predetermined temperature using the heating means. The heating temperature (solution temperature) is preferably a temperature equal to or higher than the melting point of the crystalline resin and the layer forming wax from the viewpoint of solubility of the crystalline resin and the wax. It is more preferable that the temperature is the same as the melting point, which is 5 to 5 ° C., more preferably 2 to 5 ° C. higher than the melting point of the crystalline resin and the layer forming wax.

  As the heating means, the same heating means as in the former method of forming monomer droplets can be used.

  Next, in the latter method of forming monomer droplets, the layer-forming wax-containing monomer solution in the apparatus (container) is heated to a predetermined temperature, and then the crystalline resin fine particle dispersion obtained in the step (A) is used. By adding and mixing, monomer droplets containing the crystalline resin fine particles can be formed.

  The addition amount of the crystalline resin fine particles in the crystalline resin fine particle dispersion obtained in the step (A) is 100 parts by weight of the monomer contained in the layer-forming wax-containing monomer solution in the apparatus (container). On the other hand, it is preferable that it is 30-600 mass parts, More preferably, it is the range of 100-600 mass parts.

  The temperature (liquid temperature) of the crystalline resin fine particle dispersion used for addition is preferably a temperature equal to or higher than the melting point of the crystalline resin and the wax for layer formation from the viewpoint of solubility of the crystalline resin and wax. It is more preferable that the temperature is the same as the melting point of the resin and the layer forming wax to 5 ° C., and more preferably 2 to 5 ° C. higher than the melting point of the crystalline resin and the layer forming wax. desirable.

  The average particle diameter of the monomer droplets containing the crystalline resin fine particles (see FIG. 2) formed by the latter method for forming monomer droplets is the same as that for the former method for forming monomer droplets. The particle size of the monomer droplets can also be controlled (adjusted) by the same method as the former method for forming monomer droplets.

  The average particle diameter of the monomer droplets can be measured by the same method as the former method for forming monomer droplets.

Step (D); Monomer Droplet Polymerization Step In this step (D), the monomer droplets containing the crystalline resin fine particles formed in the step (C) are polymerized (seed polymerization or the like). Specifically, in the apparatus (container) used in the step (C), after the formation of the monomer droplet containing the formed crystalline resin fine particles, the temperature (liquid temperature) in the container is maintained for a predetermined time. The polymerization is carried out by heating and stirring. By polymerization while heating and stirring, a vinyl resin layer that is a polymerized vinyl monomer is formed on the outer shell (outermost layer) portion of the monomer droplet. Since the vinyl resin layer, which is a polymer, is in a solid state, the polymer in the solid state (vinyl resin layer) and the layer forming wax are phase separated from the vinyl monomer containing the layer forming wax in the monomer droplets during the polymerization process. become. In this way, by polymerization while heating and stirring at a temperature equal to or higher than the melting point of the crystalline resin and the layer forming wax, a vinyl resin layer that is a polymer of vinyl monomer is formed on the outer shell (outermost layer) portion of the monomer droplet. The layer forming wax and the crystalline resin are present in a molten state. At this time, when the annealing temperature is equal to or higher than the melting point of the crystalline resin and the layer forming wax, the crystalline resin can be gathered in the central portion, and the layer forming wax has a low melt viscosity. Move to ooze out. That is, since the viscosity of the layer forming wax is lower than that of the crystalline resin, the layer forming wax does not exist in the center of the monomer droplet (inside the crystalline resin), but outside the central portion (with the crystalline resin in the center). A structure in which a layer forming wax (13) exists between the central crystalline resin (12) and the vinyl resin layer 14 of the outer shell is formed by being extruded to the outer shell vinyl resin layer). (See FIG. 2).

  In the apparatus (container) used in the step (C), as the polymerization temperature in the container after the formation of the monomer droplets containing the formed crystalline resin fine particles, from the viewpoint of the crystalline resin and wax solubility, The temperature is preferably equal to or higher than the melting point of the crystalline resin and the layer forming wax, more preferably the same as the melting point of the crystalline resin and the layer forming wax, which is higher by 5 ° C, and more preferably the crystalline resin. It is desirable to carry out at a temperature 2 to 5 ° C. higher than the melting point of the layer forming wax.

  The polymerization time of the monomer droplets is calculated from the half-life depending on the polymerization temperature of the polymerization initiator added in the step (C).

Step (E); Wax layer forming crystalline resin fine particle forming step (also called annealing step)
In this step (E), after polymerization of the monomer droplets in (D) above, the polymer is further maintained at a temperature equal to or higher than the melting point of the crystalline resin and the layer forming wax (= heated and stirred) to form wax layer forming crystallinity. Resin fine particles are formed (annealed). Thus, after the monomer droplet polymerization, the wax layer-forming crystalline resin fine particles are obtained by holding (annealing) at a temperature higher than the melting point of the crystalline resin and the layer-forming wax, as shown in FIG. The shape can be controlled. Specifically, when polymerization is completed, the crystalline resin (12) is unevenly distributed from the center, or the wax layer-forming crystalline resin fine particles are elliptically formed into a spherical shape by annealing treatment (heating and stirring treatment). The particle shape can be controlled so that the crystalline resin (12) is located in the center of the particle and the outer side thereof is covered with a wax layer and a vinyl resin layer in this order. After the annealing treatment, the crystalline resin and the layer forming wax that existed in the molten state in the particles are solidified by cooling to a temperature (room temperature) lower than the melting point of the crystalline resin and the layer forming wax. Thus, the crystalline resin fine particles 12 having a structure in which the crystalline resin fine particles 12 are located at the center of the particles and the wax layer 13 and the vinyl resin layer 14 are sequentially coated on the outer sides thereof are formed. That is, in this step (E), after the annealing treatment, a dispersion of wax layer-forming crystalline resin fine particles is obtained by cooling to room temperature. In the next step (F), the dispersion of the wax layer-forming crystalline resin fine particles can be used as it is.

  The annealing temperature (liquid temperature) in this step (E) may be a temperature equal to or higher than the melting point of the crystalline resin and the layer forming wax. From the viewpoint of economy and production cost, the crystalline resin is used. The temperature is preferably the same as the melting point of the layer forming wax, which is 5 to 5 ° C., more preferably 2 to 5 ° C. higher than the melting point of the crystalline resin and the melting point of the layer forming wax.

  The annealing time in this step (E) is preferably 1 to 6 hours, more preferably 2 to 6 hours from the viewpoint of the time required for forming the wax layer.

  From the viewpoint of toner performance and production suitability, the particle size of the wax layer-forming crystalline resin fine particles obtained in this step (E) is preferably, for example, in the range of 30 to 500 nm in terms of volume-based median diameter. Preferably it is the range of 80-300 nm. Since the particle size of the wax layer-forming crystalline resin fine particles is determined by the particle size of the monomer droplet, the particle size of the monomer droplet may be appropriately controlled (adjusted) by the method described above.

  The particle diameter of the wax layer-forming crystalline resin fine particles is measured by a dynamic light scattering method using “Microtrac UPA-150” (manufactured by Nikkiso Co., Ltd.). Further, as shown in FIG. 2, it is confirmed that the structure of the wax layer-forming crystalline resin fine particles 15 is a structure in which the wax layer 13 is present between the crystalline resin fine particles 12 and the vinyl resin layer 14. For example, it can confirm using well-known means, such as a transmission electron microscope (TEM). In particular, a crystalline resin having a low glass transition point (a component of the crystalline resin fine particles 12) does not migrate to the surface of the toner particles 11, and long-term storage stability is obtained while maintaining low-temperature fixability. For this purpose, the presence of the wax layer 13 is important. In order to form a layer (film thickness) having a sufficient thickness, the wax layer 13 has a mass ratio in the wax layer-forming crystalline resin fine particles. It is preferable that the ratio of the functional resin: wax for layer formation is 9: 1 to 6: 4, more preferably 8: 2 to 7: 3.

Step (F); Toner Particle Formation Step This step is a wax layer-forming crystalline resin fine particle obtained in the step (E) and a fine particle comprising an amorphous resin (hereinafter also referred to as “amorphous resin fine particle”). .) Is agglomerated and fused to form toner particles.

  In this step, the wax layer-forming crystalline resin fine particles and non-crystalline resin fine particles (hereinafter also referred to as “amorphous resin fine particles”) obtained in the step (E) are aggregated and fused. As a result, toner particles are formed.

  As a specific method for agglomerating and fusing the wax layer-forming crystalline resin fine particles and the amorphous resin fine particles, an aqueous medium (dispersion) in which the wax layer-forming crystalline resin fine particles and the amorphous resin fine particles are dispersed is used. By adding a flocculant to a critical aggregation concentration or higher, and then heating to a temperature above the glass transition point of the amorphous resin fine particles and above the melting peak temperature (° C.) of these mixtures, While the salting out of the wax layer forming crystalline resin fine particles and amorphous resin fine particles is proceeded, the fusion is proceeded in parallel, and when the particles grow to the desired particle size, an aggregation terminator is added to stop the particle growth. Furthermore, there is a method in which heating is continued to control the particle shape as necessary.

  The amount of the wax layer-forming crystalline resin fine particles added is 100 parts by mass of a dispersion in which amorphous resin fine particles and wax layer-forming crystalline resin fine particles are dispersed from the viewpoint of achieving both low temperature fixability and heat-resistant storage stability. It is preferable that it is 5-50 mass parts with respect to it, More preferably, it is the range of 10-30 mass parts.

  The addition amount of the amorphous resin fine particles is from 100 parts by mass of the dispersion liquid in which the amorphous resin fine particles and the wax layer-forming crystalline resin fine particles are dispersed from the viewpoint of both low-temperature fixability and heat-resistant storage stability. It is preferable that it is 50-95 mass parts, More preferably, it is the range of 70-90 mass parts.

The addition ratio of the amorphous resin fine particles to the wax layer-forming crystalline resin fine particles (ratio of amorphous resin fine particles: wax layer-forming crystalline resin fine particles) is 95: 5 to 50:50 in mass ratio. Preferably, it is in the range of 90:10 to 70:30.
[Amorphous resin]
As the amorphous resin related to the toner of the present invention, various known resins can be used. Specifically, for example, an amorphous polyester resin, a styrene acrylic resin, or the like can be used, and low temperature fixability can be used. From the viewpoint of obtaining image storage resistance, it is preferable to use an amorphous polyester resin. As an amorphous resin, it can use individually by 1 type or in combination of 2 or more types. As the amorphous polyester, a condensate composed of divalent and trivalent carboxylic acids and a polyhydric alcohol component can be used. As the styrene acrylic resin, a styrene monomer, a (meth) acrylic acid ester monomer, a copolymer composed of a (meth) acrylic acid monomer, or the like can be used. However, in this invention, it does not restrict | limit at all to these and a conventionally well-known amorphous resin can be utilized.

  In the present invention, the amorphous resin refers to a resin having no clear endothermic peak in a DSC curve measured using the above-mentioned differential scanning calorimeter “Diamond DSC” (manufactured by PerkinElmer).

  The amorphous resin according to the present invention preferably has a glass transition point of 25 to 60 ° C, more preferably 35 to 45 ° C.

  When the glass transition point of the amorphous resin is in the above range, sufficient low-temperature fixability and excellent storage stability can be obtained.

  The glass transition point of the amorphous resin is measured using “Diamond DSC” (Perkin Elmer).

  As a measurement procedure, 3.0 mg of a sample (amorphous 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, The intersection point is shown as the glass transition point.

  In addition, the weight average molecular weight measured by gel permeation chromatography (GPC) of the amorphous resin is preferably 7,000 to 30,000 from the viewpoint of achieving both low temperature fixability and heat resistant storage stability. Preferably it is the range of 10,000-25,000.

  For the measurement of the weight average molecular weight and peak molecular weight by gel permeation chromatography (GPC), specifically, an apparatus “HLC-8220” (manufactured by Tosoh Corporation) and a column “TSKguardcolumn + TSKgelSuperHZ-M3 series” (manufactured by Tosoh Corporation) While maintaining the column temperature at 40 ° C., tetrahydrofuran (THF) as a carrier solvent was allowed to flow at a flow rate of 0.2 ml / min, and the measurement sample was treated at room temperature for 5 minutes using an ultrasonic disperser at a concentration of 1 mg. / Ml, and then treated with a membrane filter having a pore size of 0.2 μm to obtain a sample solution. 10 μL of this sample solution is injected into the apparatus together with the carrier solvent, and a refractive index detector ( Detect and measure using RI detector The molecular weight distribution of the sample is calculated using a calibration curve measured using monodisperse polystyrene standard particles. Ten polystyrenes were used for calibration curve measurement.

  The amorphous resin fine particles are desirably used in the form of a dispersion.

  As a method for preparing amorphous resin fine particles (dispersion liquid thereof), from the viewpoint of reducing energy costs during production, a method of performing emulsion polymerization or miniemulsion polymerization using an appropriate polymerizable monomer in an aqueous medium. It is preferable to use it. The thus obtained dispersion of amorphous resin fine particles can be used as it is for the formation of toner particles.

  Amorphous resin fine particles may be composed of two or more layers of resins having different compositions. In this case, the dispersion of the first resin fine particles prepared by emulsion polymerization treatment (first-stage polymerization) according to a conventional method. A multi-stage polymerization method in which a polymerization initiator and a polymerizable monomer are added to the liquid and this system is polymerized (second-stage polymerization) can be employed.

  From the viewpoints of toner performance and production suitability, the amorphous resin fine particles preferably have a volume-based median diameter of 50 to 300 nm, more preferably 80 to 300 nm.

  The particle diameter of the amorphous resin fine particles is measured by a dynamic light scattering method using “Microtrac UPA-150” (manufactured by Nikkiso Co., Ltd.).

[Flocculant]
As the flocculant, alkali metal salts and alkaline earth metal salts can be used.

  Examples of the alkali metal constituting the flocculant include lithium, potassium and sodium, and examples of the alkaline earth metal constituting the flocculant include magnesium, calcium, strontium and barium. Of these, potassium, sodium, magnesium, calcium, and barium are preferable.

  In addition, examples of the counter ions (anions constituting the salt) of these alkali metals or alkaline earth metals include chloride ions, bromide ions, iodide ions, carbonate ions, sulfate ions, and the like.

  When the flocculant is added to the dispersion in which the amorphous resin fine particles and the wax layer-forming crystalline resin fine particles are dispersed, the temperature of the dispersion may be equal to or lower than the glass transition point of the amorphous resin fine particles. preferable.

  When the temperature of the dispersion liquid when adding the flocculant exceeds the glass transition point of the amorphous resin fine particles, it is difficult to control the particle size, and large particles are likely to be generated.

  Thus, in this step (F), when the temperature of the dispersion liquid in which the amorphous resin fine particles and the wax layer-forming crystalline resin fine particles are dispersed is equal to or lower than the glass transition point of the amorphous resin fine particles. In addition, it is necessary to add a flocculant while stirring the dispersion, and then immediately start heating the dispersion to a temperature equal to or higher than the glass transition point of the amorphous resin fine particles.

  The heating temperature in this toner particle forming step (the temperature for fusing the agglomerated particles after agglomeration) is equal to or higher than the glass transition point of the amorphous resin fine particles (the glass transition of the amorphous resin fine particles). Point + 10 ° C.) to (glass transition point of amorphous resin fine particles + 50 ° C.), particularly preferably (glass transition point of amorphous resin fine particles + 15 ° C.) to (glass transition point of amorphous resin fine particles + 40 ° C.). ).

  The flocculant may be added in an aqueous medium so that the flocculant is equal to or higher than the critical flocculent concentration. However, the dispersion 100 is obtained by dispersing amorphous resin fine particles and wax layer-forming crystalline resin fine particles. It is preferable that it is 1-10 mass parts with respect to a mass part, More preferably, it is the range of 1-5 mass parts.

  The toner particles constituting the toner of the present invention have a core-shell structure comprising a core particle containing a crystalline resin and a layer forming wax, and a shell layer covering the surface of the core particle with a resin (amorphous resin). You may have. Since the toner particles have a core-shell structure, high production stability and storage stability can be expected.

  Here, the core-shell structure is not limited as long as the shell layer covers the core particles, and the shell layer completely covers the core particles as well as a part of the core particles. There may be. The shell layer may have a multilayer structure of two or more layers made of resins having different compositions.

  In the toner having such a configuration, the content ratio of the resin constituting the shell layer (shell resin) is preferably 5% by mass or more and 30% by mass or less with respect to the whole toner.

  As the shell resin, a resin having a high glass transition point that is incompatible with a resin other than the crystalline resin constituting the core particle is used.

  Here, as a shell resin, it is preferable that the glass transition point is 45 degreeC or more and 60 degrees C or less. Moreover, it is preferable that the weight average molecular weight is 8,000 or more and 50,000 or less.

  When the toner particles have a core-shell structure as described above, first, the amorphous resin fine particles and the wax layer-forming crystalline resin fine particles are aggregated to form core particles, and then the fine particles made of the shell resin are formed into the core particles. It can manufacture by performing the shelling process made to aggregate with respect to particle | grains.

  The toner particles constituting the toner of the present invention may contain an internal additive such as a colorant, magnetic powder, a charge control agent, and a release agent, if necessary.

  In this way, when the toner particles contain an internal additive such as a colorant, a release agent, a charge control agent, and magnetic powder, the amorphous resin fine particles are formed as containing these internal additives. By doing so, it can be introduced into the toner particles. Also, a dispersion of the internal additive fine particles is prepared and added to the toner particles by adding it in the toner particle forming step and aggregating and fusing together with the amorphous fine particles and the wax layer forming crystalline resin fine particles. You can also. Moreover, you may combine these methods.

[Colorant]
As the colorant, a known inorganic or organic colorant can be used. Specific colorants are shown below.

  Examples of the black colorant include carbon black such as furnace black, channel black, acetylene black, thermal black and lamp black, and magnetic powder such as magnetite and ferrite.

  Examples of the colorant for magenta or red include C.I. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 5, C.I. I. Pigment red 6, C.I. I. Pigment red 7, C.I. I. Pigment red 15, C.I. I. Pigment red 16, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 53: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 123, C.I. I. Pigment red 139, C.I. I. Pigment red 144, C.I. I. Pigment red 149, C.I. I. Pigment red 166, C.I. I. Pigment red 177, C.I. I. Pigment red 178, C.I. I. And CI Pigment Red 222.

  Examples of the colorant for orange or yellow include C.I. I. Pigment orange 31, C.I. I. Pigment orange 43, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. Pigment yellow 138, and the like.

  Examples of the colorant for green or cyan include C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 15: 4, C.I. I. Pigment blue 16, C.I. I. Pigment blue 60, C.I. I. Pigment blue 62, C.I. I. Pigment blue 66, C.I. I. And CI Pigment Green 7.

  These colorants can be used alone or in combination of two or more.

  The addition amount of the colorant is preferably 1 to 20 parts by mass, more preferably 1 to 100 parts by mass of the dispersion liquid in which the amorphous resin fine particles and the wax layer-forming crystalline resin fine particles are dispersed. It is the range of -15 mass parts.

  The colorant may be added to the aqueous medium (dispersion) in which the wax layer-forming crystalline resin fine particles and amorphous resin fine particles are dispersed before adding the flocculant.

  The colorant is desirably added in the form of a colorant fine particle dispersion. The particle diameter of the colorant fine particles in this case is preferably from 50 to 300 nm, more preferably from 80 to 300 nm, from the viewpoint of toner performance and production suitability. Moreover, it is preferable that content of a coloring agent microparticles | fine-particles is 1-20 mass% with respect to a coloring agent fine particle dispersion, More preferably, it is the range of 1-15 mass%. The dispersion medium of the colorant fine particle dispersion is preferably an aqueous medium containing a surfactant, and more preferably water containing an ionic surfactant (ion-exchanged water). The content of the surfactant is preferably 1 to 10 parts by mass, more preferably 1 to 5 parts by mass with respect to 100 parts by mass of the aqueous medium (excluding the surfactant). In addition, about an aqueous medium and surfactant, the thing similar to the "aqueous medium (a surfactant is included)" used for preparation of the emulsion of the said process (A) can be used.

〔Release agent〕
As the release agent, various known waxes can be used, and the same wax as the layer forming wax can also be used.

  Specific examples of the wax used as the release agent include polyolefin waxes such as polyethylene wax and polypropylene wax; branched hydrocarbon waxes such as microcrystalline wax; long-chain hydrocarbon waxes such as paraffin wax and sazol wax. Dialkyl ketone waxes such as distearyl ketone; carnauba wax, montan wax, behenyl behenate, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, Ester waxes such as 1,18-octadecanediol distearate, tristearyl trimellitate, distearyl maleate; ethylenediamine behenylamide, trimelli Such as amide-based waxes such as acid tristearyl amide.

  The addition amount of the release agent is preferably 1 to 20 parts by mass, more preferably 100 parts by mass with respect to 100 parts by mass of the dispersion in which amorphous resin fine particles and wax layer-forming crystalline resin fine particles are dispersed. It is the range of 1-15 mass parts.

  In addition, when the amorphous resin is a styrene acrylic resin having a three-layer structure of a core part / intermediate layer / outer layer and encapsulating a wax having the same function as the above-mentioned release agent in the intermediate layer. The release agent may not be used, but may be used in combination. On the other hand, when an amorphous polyester resin is used as the amorphous resin, a release agent (wax) cannot be included in the amorphous resin. It is desirable to add a release agent within the range.

  The release agent may be added to the aqueous medium (dispersion liquid) in which the wax layer-forming crystalline resin fine particles and amorphous resin fine particles are dispersed before adding the flocculant.

  The particle size of the release agent fine particles at this time is preferably 50 to 300 nm, more preferably 80 to 300 nm in terms of volume-based median diameter from the viewpoint of toner performance and production suitability. Moreover, it is preferable that content of mold release agent microparticles | fine-particles is 1-20 mass% with respect to mold release agent microparticle dispersion liquid, More preferably, it is the range of 1-15 mass%. The dispersion medium of the release agent fine particle dispersion is preferably an aqueous medium containing a surfactant, and more preferably water containing an ionic surfactant (ion exchange water). The content of the surfactant is preferably 1 to 10 parts by mass, more preferably 1 to 5 parts by mass with respect to 100 parts by mass of the aqueous medium (excluding the surfactant). In addition, about an aqueous medium and surfactant, the thing similar to the "aqueous medium (a surfactant is included)" used for preparation of the emulsion of the said process (A) can be used.

  The addition timing of the aggregation terminator may be added when the wax layer forming crystalline resin fine particles and amorphous resin fine particles are aggregated and melted to grow to a desired particle diameter. Specifically, the desired particle diameter is preferably 3 to 10 μm, more preferably 5 to 8 μm, in terms of volume-based median diameter. Whether or not the particles have grown to a desired particle diameter can be sufficiently managed (controlled) by obtaining a relationship between the heating time at the time of melting and the particle diameter by conducting a preliminary experiment or the like in advance. .

  The heating temperature in the case of adding a coagulation terminator to stop particle growth and further performing heating to control the particle shape as necessary is the heating temperature in the toner particle forming step described above ( It can be performed in a temperature range similar to the range of the temperature for fusing the aggregated particles after the aggregation. Specifically, it is equal to or higher than the glass transition point of the amorphous resin fine particles, and is (glass transition point of the amorphous resin fine particles + 10 ° C.) to (glass transition point of the amorphous resin fine particles + 50 ° C.). Preferably, it is (glass transition point of amorphous resin fine particles + 15 ° C.) to (glass transition point of amorphous resin fine particles + 40 ° C.).

Step (G); filtration, washing step, step (H); drying step The filtration, washing step and drying step can be carried out by employing various known methods.

[Toner particle size]
The particle size of the toner particles constituting the toner of the present invention is preferably 3 to 10 μm, and more preferably 5 to 8 μm, for example, on a volume basis median diameter.

  When the volume-based median diameter of the toner particles 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 toner particles is measured and calculated using a measuring apparatus in which a computer system for data processing (Beckman Coulter, Inc.) is connected to “Coulter Multisizer 3” (Beckman Coulter, Inc.). .

  Specifically, 0.02 g of toner is added to 20 mL of a surfactant solution (for example, a surfactant solution in which a neutral detergent containing a surfactant component is diluted 10-fold with pure water for the purpose of dispersing the toner). Then, ultrasonic dispersion treatment was performed for 1 minute to prepare a toner particle dispersion, and this toner particle dispersion was added to a beaker containing “ISOTON II” (manufactured by Beckman Coulter) in a sample stand. Then, inject with a pipette until the displayed concentration of the measuring device is 5% to 10%. Here, a reproducible measurement value can be obtained by setting the concentration range. In the measuring apparatus, the measurement particle count number is 25000, the aperture diameter is 100 μm, and the frequency value is calculated by dividing the range of 2 to 60 μm, which is the measurement range, into 256 parts. % Particle diameter is defined as a volume-based median diameter.

[Toner circularity]
The toner particles constituting the toner of the present invention preferably have an average circularity of 0.930 to 1.000, more preferably 0.950 to 0.995, from the viewpoint of improving transfer efficiency.

  The circularity of the toner is a value measured by “FPIA-2100” (manufactured by Sysmex).

  Specifically, after adding a sample (toner) to a commercially available special sheath solution in which a surfactant is dissolved, the sample is sonicated for 1 minute to prepare a dispersion. With respect to the liquid, using “FPIA-2100”, the measurement conditions are set to the HPF (high magnification imaging) mode, and the measurement is performed at an appropriate concentration of 3000 to 10,000 HPF detections. Here, a reproducible measurement value can be obtained by using this range. And based on the measured value obtained by this measurement, the circularity shown by the following formula (T) is calculated.

  Further, the average circularity is calculated by adding the average value of the circularity of each toner particle that is the measurement target of the above-mentioned circularity, that is, the circularity of each toner particle, and dividing by the total number of toner particles.

Step (I): External additive addition step This external additive addition step is a step of adding and mixing external additives as necessary to the dried toner particles.

  The toner particles prepared through the steps up to the drying step can be used as toners as they are, but from the viewpoint of improving the charging performance, fluidity, or cleaning properties of the toner, a known inorganic surface is used on the surface. It is preferable to add particles such as fine particles and organic fine particles, and a lubricant as external additives.

  Specific examples of the external additive include inorganic oxide fine particles such as silica fine particles, alumina fine particles and titanium oxide fine particles, inorganic stearate compound fine particles such as aluminum stearate fine particles and zinc stearate fine particles, or strontium titanate and titanium. Examples include inorganic fine particles such as inorganic titanic acid compound fine particles such as zinc oxide.

  These inorganic fine particles are preferably those subjected to surface treatment with a silane coupling agent, a titanium coupling agent, a higher fatty acid, silicone oil, or the like from the viewpoint of heat-resistant storage stability and environmental stability.

  The addition amount of the external additive is 0.05 to 5 parts by mass, preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the toner. In addition, various external additives may be used in combination.

  Examples of the method for adding the external additive include a dry method in which the external additive is added in powder form to the dried toner particles. Examples of the mixing device include mechanical mixing devices such as a Henschel mixer and a coffee mill. .

(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.

  In the case where the toner of the present invention is used as a two-component developer, the carrier is conventionally a ferromagnetic metal such as iron, a ferromagnetic metal and an alloy such as aluminum and lead, and a compound of a ferromagnetic metal such as ferrite and magnetite. Magnetic particles made of known materials can be used, and ferrite particles are particularly preferable. As the carrier, a coated carrier in which the surface of magnetic particles is coated with a coating agent such as a resin, a binder type carrier in which magnetic fine powder is dispersed in a binder resin, and the like can also be used. The coating resin constituting the coat carrier is not particularly limited, and examples thereof include olefin resins, styrene resins, styrene-acrylic resins, silicone resins, ester resins, and fluorine resins. Moreover, it does not specifically limit as resin which comprises a resin dispersion type carrier, A well-known thing can be used, For example, a styrene-acrylic-type resin, a polyester resin, a fluororesin, a phenol resin etc. can be used.

  The volume-based median diameter of the carrier is preferably 20 to 100 μm, and more preferably 20 to 60 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.

  According to the method for producing a toner of the present invention as described above, the composite fine particles composed of a crystalline resin having a specific peak molecular weight and an ester wax are heated to a temperature equal to or higher than the melting point of the crystalline resin. Thus, it is possible to produce a toner that has excellent long-term storage stability while ensuring sufficient low-temperature fixability and does not require strict temperature control during transportation and storage in a warehouse.

<Second Embodiment>
The second embodiment of the toner production method of the present invention does not perform the wax layer-forming crystalline resin fine particle forming step (annealing step) in the first embodiment, and in the toner particle forming step, the monomer droplet polymerization is performed. The wax layer-forming crystalline resin fine particles and the amorphous resin fine particles obtained in the process are aggregated at a temperature equal to or higher than the melting point of the crystalline resin, and the wax layer-forming crystalline resin fine particles are aggregated at a temperature equal to or higher than the melting point of the crystalline resin. The method has the same steps as those of the first embodiment except that the fusion is performed while reheating (annealing).

  According to the toner manufacturing method according to the second embodiment as described above, the same effects as those in the first embodiment can be obtained.

  Although the embodiments of the toner and the manufacturing method thereof according to the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be added.

  Specific examples of the present invention will be described below, but the present invention is not limited to these examples.

(Synthesis Example 1 of crystalline polyester resin)
In a reaction vessel equipped with a cooling tube, a nitrogen introducing tube and a stirrer, 230 parts by mass of 1,10-dodecanedioic acid, 176 parts by mass of 1,9-nonanediol, and catalyst: 0.5 parts by mass of titanium tetrabutoxide are placed. The reaction was carried out for 8 hours while distilling off the water produced at 180 ° C. under a nitrogen stream.

  Next, while gradually raising the temperature to 225 ° C., the reaction was carried out for 4 hours while distilling off the generated water and 1,9-nonanediol under a nitrogen stream. Furthermore, after reacting under reduced pressure of 665-2660 Pa, it took out from the reaction tank and cooled to room temperature, and crystalline polyester resin [PEs1] was obtained. The crystalline polyester resin [PEs1] had a weight average molecular weight of 23,000, a peak molecular weight of 20,000, and a melting point of 67.6 ° C.

(Synthesis Example 2 of crystalline polyester resin)
Similar to Synthesis Example 1 except that 202 parts by mass of sebacic acid instead of 230 parts by mass of 1,10-dodecanedioic acid and 192 parts by mass of 1,10-decanediol instead of 176 parts by mass of 1,9-nonanediol were used. Thus, a crystalline polyester resin [PEs2] was obtained. The crystalline polyester resin [PEs2] had a weight average molecular weight of 18,000, a peak molecular weight of 16,000, and a melting point of 62.1 ° C.

(Synthesis example 3 of crystalline polyester resin)
Synthesis Example 1 except that 172 parts by mass of octanedioic acid instead of 230 parts by mass of 1,10-dodecanedioic acid and 161 parts by mass of 1,8-octanediol were used instead of 176 parts by mass of 1,9-nonanediol Similarly, a crystalline polyester resin [PEs3] was obtained. The crystalline polyester resin [PEs3] had a weight average molecular weight of 20,000, a peak molecular weight of 19,000, and a melting point of 72.3 ° C.

(Synthesis example 4 of crystalline polyester resin)
The same as Synthesis Example 1 except that 146 parts by mass of adipic acid instead of 230 parts by mass of 1,10-dodecanedioic acid and 130 parts by mass of 1,6-hexanediol instead of 176 parts by mass of 1,9-nonanediol were used. Thus, a crystalline polyester resin [PEs4] was obtained. The crystalline polyester resin [PEs4] had a weight average molecular weight of 15,000, a peak molecular weight of 13,000, and a melting point of 57.4 ° C.

<Preparation of crystalline polyester resin fine particle dispersion (C1); Step (A)>
The crystalline polyester resin [PEs1] (melting point: 67.6 ° C.) was added to a jacketed 3 liter reaction tank (Tokyo Rika Kikai Co., Ltd .: BJ-30N) equipped with a condenser, thermometer, water dropping device and anchor blade. 300 parts by mass and 260 parts by mass of ethyl acetate were added, and the resin was dissolved while stirring and mixing at 100 rpm while maintaining at 70 ° C. in a water circulation thermostat (preparation of crystalline resin solution). Thereafter, the stirring speed was set to 150 rpm, and 17 parts by mass of 10% by mass ammonia water (reagent) was added over 10 minutes, and then ion-exchanged water kept at 70 ° C. at a rate of 7 parts by mass / min. Part of the mixture was added dropwise to cause phase inversion to obtain an emulsion (preparation of emulsion). Immediately, 800 parts by mass of the obtained emulsified liquid and 700 parts by mass of ion-exchanged water were put into a 2-liter eggplant flask and set in an evaporator (Tokyo Rika Kikai Co., Ltd.) equipped with a vacuum control unit via a trap ball. did. While rotating the eggplant flask, the mixture was heated in a hot water bath at 50 ° C., and the pressure was reduced to 7 kPa while paying attention to bumping to remove the solvent (removal of the organic solvent). When the solvent recovery amount reached 1100 parts by mass, the pressure was returned to normal pressure, and the eggplant flask was cooled with water to obtain a dispersion (preparation of crystalline resin fine particle dispersion). There was no solvent odor in the obtained dispersion. Thereafter, ion-exchanged water was added to adjust the solid content concentration to 20% by mass, and this was used as a crystalline polyester resin fine particle dispersion (C1). The particle diameter of the crystalline polyester resin fine particles in the obtained dispersion (C1) was 165 nm in terms of volume-based median diameter.

<Preparation of Crystalline Polyester Resin Fine Particle Dispersion (C2); Step (A)>
Instead of [PEs1] (melting point: 67.6 ° C.) as the crystalline polyester resin, [PEs2] (melting point: 62.1 ° C.) is used in a water-circulating thermostat at the time of preparing the crystalline resin solution. The crystalline polyester resin was prepared in the same manner as the preparation of the crystalline polyester resin dispersion (C1) except that ion-exchanged water maintained at 65 ° C. and maintained at 65 ° C. was used instead of maintaining at 65 ° C. A fine particle dispersion (C2) was obtained. The particle diameter of the crystalline polyester resin fine particles in the obtained dispersion (C2) was 144 nm in terms of volume-based median diameter.

<Preparation of crystalline polyester resin fine particle dispersion (C3); Step (A)>
Instead of [PEs1] (melting point 67.6 ° C.) as the crystalline polyester resin, [PEs3] (melting point 72.3.6 ° C.) is used in the water circulating thermostatic bath for the preparation of the crystalline resin solution. In the same manner as the preparation of the crystalline polyester resin dispersion (C1) except that ion-exchanged water kept at 75 ° C. and kept at 75 ° C. was used instead of maintaining at 70 ° C. A polyester resin fine particle dispersion (C3) was obtained. The particle diameter of the crystalline polyester resin fine particles in the obtained dispersion (C3) was 172 nm in terms of volume-based median diameter.

<Preparation of crystalline polyester resin fine particle dispersion (C4); Step (A)>
Instead of [PEs1] (melting point 67.6 ° C) as the crystalline polyester resin, [PEs4] (melting point 57.4 ° C) is used in a water circulating thermostatic bath for the preparation of the crystalline resin solution. The crystalline polyester resin was prepared in the same manner as the preparation of the crystalline polyester resin dispersion (C1) except that ion-exchanged water maintained at 60 ° C. was used instead of maintaining at 60 ° C. A fine particle dispersion (C4) was obtained. The particle diameter of the crystalline polyester resin fine particles in the obtained dispersion (C4) was 153 nm in terms of volume-based median diameter.

<Preparation of Wax Layer-Forming Crystalline Polyester Resin Fine Particle Dispersion (WC1)>
In a flask equipped with a stirrer, a layer-forming wax was added to a monomer mixture composed of 165 parts by mass of styrene, 59 parts by mass of n-butyl acrylate, 12 parts by mass of methacrylic acid, and 4.0 parts by mass of n-octyl mercaptan. 127 parts by weight of behenyl behenate (melting point: 71.2 ° C.) was added and heated to 75 ° C. and dissolved to prepare a wax-containing monomer solution (monomer mixed solution) for layer formation (step (B )).

  On the other hand, 1450 parts by mass of the crystalline polyester resin fine particle dispersion (C1) and 1250 parts by mass of ion-exchanged water are charged in a 5 L reaction vessel equipped with a stirrer, a temperature sensor, a cooling pipe, and a nitrogen introducing device up to 80 ° C. After heating, a polymerization initiator solution in which 3.0 parts by mass of potassium persulfate was dissolved in 57 parts by mass of ion-exchanged water was added, and the layer-forming wax-containing monomer solution (monomer mixed solution) was further added for 2 hours. To form monomer droplets containing crystalline polyester resin fine particles (step (C)), and the monomer droplets are heated and stirred at 80 ° C. for 2 hours to perform seed polymerization (step (D) )), And further kept at that temperature for 1 hour (heating and stirring) (annealing treatment was performed). Then, the wax layer formation crystalline polyester resin fine particle dispersion (WC1) was obtained by cooling to 28 degreeC (process (E)).

<Preparation of Wax Layer-Forming Crystalline Polyester Resin Fine Particle Dispersion (WC2-WC4)>
Similar to the preparation of the wax layer-forming crystalline polyester resin fine particle dispersion (WC1) except that the crystalline polyester resin fine particle dispersion (C2 to C4) was used instead of the crystalline polyester resin fine particle dispersion (C1). Wax layer-forming crystalline polyester resin fine particle dispersions (WC2 to WC4) were obtained.

<Preparation of Wax Layer-Forming Crystalline Polyester Resin Fine Particle Dispersion (WC5)>
Wax layer-forming crystalline polyester, except that the wax for layer formation is changed to paraffin wax FNP-0090 (melting point 89 ° C.) instead of behenyl behenate and the melting temperature / seed polymerization temperature / annealing temperature is set to 90 ° C. A wax layer-forming crystalline polyester resin fine particle dispersion (WC5) was obtained in the same manner as in the preparation of the resin fine particle dispersion (WC1).

<Preparation of Wax Layer-Forming Crystalline Polyester Resin Fine Particle Dispersion (WC6)>
In the layer-forming wax-containing monomer solution (monomer mixed solution), 165 parts by mass of styrene was 136 parts by mass, 59 parts by mass of n-butyl acrylate was 67 parts by mass, and 12 parts by mass of methacrylic acid was changed to 33 parts by mass. Except for the above, a wax layer-forming crystalline polyester resin fine particle dispersion (WC6) was obtained in the same manner as in the preparation of the wax layer-forming crystalline polyester resin fine particle dispersion (WC1).

<Preparation of Crystalline Polyester Resin Fine Particle Dispersion (WC7) by Seed Polymerization Using Only Vinyl Monomer Not Containing Layer Forming Wax>
In a flask equipped with a stirrer, a monomer solution containing only 165 parts by mass of styrene, 59 parts by mass of n-butyl acrylate, 12 parts by mass of methacrylic acid, and 4.0 parts by mass of n-octyl mercaptan (single solution) (Mixer mixed solution) was prepared.

  On the other hand, 1450 parts by mass of the crystalline polyester resin fine particle dispersion (C1) and 1250 parts by mass of ion-exchanged water are charged in a 5 L reaction vessel equipped with a stirrer, a temperature sensor, a cooling pipe, and a nitrogen introducing device up to 80 ° C. After heating, a polymerization initiator solution in which 3.0 parts by mass of potassium persulfate was dissolved in 57 parts by mass of ion-exchanged water was added, and a monomer solution (monomer mixed solution) not containing the layer forming wax was further added. Dropping over 2 hours to form monomer droplets containing crystalline polyester resin fine particles, seed polymerization is performed by heating and stirring the monomer droplets at 80 ° C. for 2 hours, followed by annealing treatment Without cooling to 28 ° C., a crystalline polyester resin fine particle dispersion (WC7) by seed polymerization was obtained.

<Preparation of Amorphous Resin Dispersion A1> -Amorphous Polyester Resin-
(Monomer component)
-Bisphenol A ethylene oxide 2.2 mol adduct: 40 mol%
-Bisphenol A propylene oxide 2.2 mol adduct: 60 mol%
・ Terephthalic acid: 62 mol%
・ Fumaric acid: 40 mol%
-Trimellitic anhydride: 3 mol%.

  In a reaction vessel equipped with a stirrer, a thermometer, a condenser and a nitrogen gas introduction pipe, fumaric acid and trimellitic anhydride other than the above monomer components, and tin dioctanoate as a catalyst in a total of 100 parts by mass of the above monomer components In contrast, 0.25 part by mass was charged. After reacting at 235 ° C. for 6 hours under a nitrogen gas stream, the temperature was lowered to 200 ° C., and the fumaric acid and trimellitic anhydride were added and reacted for 1 hour. The temperature was further raised to 220 ° C. over 4 hours, and polymerization was performed under a pressure of 10 kPa until a desired molecular weight (about 20,000) was obtained, thereby obtaining a light yellow transparent amorphous polyester resin. The weight average molecular weight measured by GPC of the obtained amorphous polyester resin was 12,000.

  While maintaining a jacketed 3 liter reaction tank (manufactured by Tokyo Rika Kikai Co., Ltd .: BJ-30N) equipped with a condenser, a thermometer, a water dropping device, and an anchor wing at 40 ° C. in a water circulation thermostat, the reaction tank Into this, a mixed solvent of 160 parts by mass of ethyl acetate and 100 parts by mass of isopropyl alcohol was added, and 300 parts by mass of the above amorphous polyester resin was added thereto, and the mixture was stirred at 150 rpm using a three-one motor and dissolved to obtain oil. Got the phase. To the stirred oil phase, 14 parts by mass of a 10% by mass aqueous ammonia solution was added dropwise for 5 minutes, and after mixing for 10 minutes, 900 parts by mass of ion-exchanged water was further added dropwise at a rate of 7 parts by mass per minute. The phase was inverted to obtain an emulsion.

  Immediately, 800 parts by mass of the obtained emulsified liquid and 700 parts by mass of ion-exchanged water were put into a 2-liter eggplant flask and set in an evaporator (Tokyo Rika Kikai Co., Ltd.) equipped with a vacuum control unit via a trap ball. did. While rotating the eggplant flask, the mixture was heated in a hot water bath at 60 ° C., and the solvent was removed by reducing the pressure to 7 kPa while paying attention to bumping. When the amount of recovered solvent reached 1,100 parts by mass, the pressure was returned to normal pressure, and the eggplant flask was cooled with water to obtain a dispersion. There was no solvent odor in the obtained dispersion. Then, ion-exchange water was added and it prepared so that solid content concentration might be 20 mass%, and this was made into the amorphous polyester resin dispersion [A1]. Further, the amorphous polyester resin fine particles in the dispersion [A1] had a volume-based median diameter of 150 nm.

<Preparation of Amorphous Resin Dispersion A2> -Styrene Acrylic Resin-
(1) First-stage polymerization In a 5 L reaction vessel equipped with a stirrer, temperature sensor, cooling pipe, and nitrogen introducing device, 4 parts by mass of sodium polyoxyethylene-2-dodecyl ether sulfate is dissolved in 3040 parts by mass of ion-exchanged water. The prepared surfactant solution was charged, and the internal temperature was raised to 80 ° C. while stirring at a stirring speed of 230 rpm under a nitrogen stream. To this surfactant solution, an initiator solution in which 10 parts by mass of a polymerization initiator (potassium persulfate: KPS) was dissolved in 400 parts by mass of ion-exchanged water was added to a temperature of 75 ° C., and then 532 parts by mass of styrene. A monomer mixture composed of 200 parts by mass of n-butyl acrylate, 68 parts by mass of methacrylic acid and 16.4 parts by mass of n-octyl mercaptan was dropped over 1 hour, and the system was heated at 75 ° C. for 2 hours. Polymerization (first stage polymerization) was performed by stirring to prepare a dispersion of resin fine particles for core part [A2-1]. The weight average molecular weight of the resin fine particles for core part [A2-1] was 16,500.

(2) Second-stage polymerization (formation of an intermediate layer containing a release agent (wax))
In a flask equipped with a stirrer, a monomer mixture comprising 101.1 parts by mass of styrene, 62.2 parts by mass of n-butyl acrylate, 12.3 parts by mass of methacrylic acid, and 1.75 parts by mass of n-octyl mercaptan As a release agent, 93.8 parts by mass of paraffin wax “HNP-57” (manufactured by Nippon Seiki Co., Ltd.) was added, and the mixture was heated to 90 ° C. and dissolved to prepare a monomer solution.

  On the other hand, a surfactant solution in which 3 parts by mass of sodium polyoxyethylene-2-dodecyl ether sulfate was dissolved in 1560 parts by mass of ion-exchanged water was heated to 98 ° C., and the above core part resin was added to the surfactant solution. After adding 32.8 parts by mass of the fine particle [A2-1] dispersion in terms of solid content, the above monomer solution is obtained by a mechanical disperser “CLEAMIX” (manufactured by M Technique Co., Ltd.) having a circulation path. Was mixed and dispersed for 8 hours to prepare a dispersion liquid in which emulsified particles having a dispersed particle diameter of 340 nm were dispersed.

  Next, an initiator solution in which 6 parts by mass of potassium persulfate is dissolved in 200 parts by mass of ion-exchanged water is added to this dispersion, and this system is polymerized by heating and stirring at 98 ° C. for 12 hours (second). Step polymerization) was performed to prepare a dispersion of resin fine particles [A2-2] composed of a core part / intermediate layer. The resin fine particles [A2-2] composed of the core / intermediate layer had a weight average molecular weight of 23,000.

(3) Third stage polymerization (formation of outer layer)
An initiator solution prepared by dissolving 5.45 parts by mass of potassium persulfate in 220 parts by mass of ion-exchanged water is added to the dispersion of the resin fine particles [A2-2] composed of the core part / intermediate layer. Under temperature conditions, a monomer mixed solution composed of 293.8 parts by mass of styrene, 154.1 parts by mass of n-butyl acrylate, and 7.08 parts by mass of n-octyl mercaptan was dropped over 1 hour. After completion of the dropwise addition, polymerization (third stage polymerization) was performed by heating and stirring for 2 hours, and then cooled to 28 ° C., whereby amorphous styrene acrylic resin fine particles [A2-3] (core part / intermediate layer) / A dispersion liquid [A2] of resin fine particles [A2-3] having a three-layer structure of the outer layer was obtained. The amorphous styrene acrylic resin fine particles [A2-3] (core fine particles / intermediate layer / outer layer resin fine particles [A2-3]) had a weight average molecular weight of 26,800. The resin fine particles [A2-3] in the dispersion [A2] had a volume-based median diameter of 220 nm.

<Preparation of release agent fine particle dispersion>
As a release agent, 60 parts by mass of paraffin wax FNP-0090 (melting point 89 ° C.), 5 parts by mass of an ionic surfactant “Neogen RK” (Daiichi Kogyo Seiyaku Co., Ltd.), and 240 parts by mass of ion-exchanged water are mixed. The obtained solution was heated to 95 ° C. and sufficiently dispersed using a homogenizer “Ultratax T50” (manufactured by IKA), and then subjected to dispersion treatment using a pressure discharge type gorin homogenizer, whereby the volume average diameter was 240 nm, solid A release agent fine particle dispersion [W] having a partial mass of 20 parts by mass was prepared.

<Preparation of colorant fine particle dispersion>
Carbon black “Regal 330” (manufactured by Cabot) 10 parts by mass C.I. I. Pigment Blue 15: 3 40 parts by weight Ionic surfactant (sodium n-dodecylbenzenesulfonate) 8 parts by weight 250 parts by weight of ion-exchanged water is mixed and dissolved, and “Ultra Turrax T50” (manufactured by IKA) is used for 10 minutes. After the dispersion treatment, a black colorant fine particle dispersion [K] in which colorant fine particles having a volume-based median diameter of 310 nm are dispersed was prepared by treatment with an ultrasonic disperser for 20 minutes.

<Toner Preparation Example 1>
Amorphous polyester resin dispersion [A1] (solid content conversion) 560 parts by weight Wax layer-forming crystalline polyester resin fine particle dispersion [WC1] 340 parts by weight Release agent fine particle dispersion [W] 65 parts by weight Black colorant fine particles Dispersion [K] 80 parts by mass was put into a round stainless steel flask and adjusted to 20 ° C. while stirring with 300 parts by mass of ion-exchanged water. Thereafter, the mixture was sufficiently mixed and dispersed by “Ultra Turrax T50” (manufactured by IKA) to prepare a dispersion. Next, 0.1 part by mass of polyaluminum chloride as a flocculant was added to the dispersion, and the dispersion treatment was continued with “Ultra Turrax T50” (manufactured by IKA). After the dispersion treatment, the flask was put into a heating oil bath, and the flask was heated to 45 ° C. with stirring (aggregation started by the heating). The flask was kept at 45 ° C. for 60 minutes, and the pH of the system was adjusted to 8 with a 0.5 mol / liter sodium hydroxide aqueous solution. Thereafter, the stainless steel flask was sealed and stirring was continued with a magnetic seal. The mixture is heated to 90 ° C. (melting starts by the heating), and the pH in the system is adjusted to 7 using 0.5 mol / liter of nitric acid, and kept for 30 minutes to continue the reaction. Toner particles [1] were formed (step (F); see FIG. 1). The obtained toner particles [1] had a volume-based median diameter of 6.4 μm.

  After completion of the reaction, a multi-tubular heat exchanger was used (refrigerant was cold water at 5 ° C.), and the flow rate of cold water was adjusted to a cooling rate of −25 ° C./min and rapidly cooled to 30 ° C. After rapid cooling, the mixture was filtered and thoroughly washed with ion exchange water, and then subjected to solid-liquid separation by Nutsche suction filtration. Further, the separated particles were redispersed in 3 liters of ion exchange water at 43 ° C., and washed by stirring for 15 minutes under the condition of 300 rpm (step (G)). Then, it air-dried at 42 degreeC (process (H)). To 100 parts by mass of the dried toner particles [1], 0.6 parts by mass of hydrophobic silica having an average primary particle diameter of 17 nm and 1.0 part by mass of hydrophobic silica having an average primary particle diameter of 80 nm are added as external additives. The outer peripheral speed of the Henschel mixer was set to 35 m / sec and the external additive was mixed for 20 minutes, and then passed through a 400 mesh stainless steel sieve to obtain toner [1] (step (I)). ). The obtained toner [1] had a volume-based median diameter of 6.5 μm. When TEM observation of the crystalline polyester domain of the toner particle [1] was performed, 5 to 50 crystalline polyester (fine particle) domains of 0.1 to 0.9 μm were confirmed in each of the five toners ( (See FIG. 1). The toner particle [1] has a structure in which a release agent fine particle and a black colorant fine particle are dispersed in an amorphous polyester resin matrix in addition to the crystalline polyester (fine particle) (the following toner particles). The same applies to [2] to [9]. Such a structure can be confirmed (analyzed) together when measuring the domain diameter and the number of domains of the crystalline resin in the “evaluation” toner described later.

<Toner Preparation Examples 2 to 6>
In Example 1 of toner production, the same procedure was performed except that the wax layer-forming crystalline polyester resin fine particle dispersions [WC2] to [WC6] were used instead of the wax layer-forming crystalline polyester resin fine particle dispersion [WC1]. Toner [2] to Toner [6] were prepared. The volume based median diameters of the obtained toners [2] to [6] were all 6.5 μm. When TEM observation of the crystalline polyester domains of the toner particles [2] to [6] was performed, all of the toner particles [2] to [6] had 0.1 to 0.9 μm crystals. 5 to 50 functional polyester (fine particle) domains were confirmed (see FIG. 1).

<Toner Preparation Example 7>
In Toner Preparation Example 1, amorphous styrene acrylic resin fine particles [A2] (core fine particles / interlayer / outer layer resin fine particles [A2]) were used instead of the amorphous polyester resin dispersion [A1]. A toner [7] was prepared in the same manner except that the release agent fine particle dispersion [W] was not used. The volume-based median diameter of the obtained toner [7] was 6.5 μm. As a result of TEM observation of the crystalline polyester domains of the toner particles [7], 5 to 50 crystalline polyester (fine particle) domains of 0.1 to 0.9 μm were confirmed in each of the five toners ( (See FIG. 1). The release agent fine particle dispersion [W] was not used in the case of amorphous styrene acrylic resin fine particles [A2] (resin fine particles [A2] having a three-layer structure of core / intermediate layer / outer layer). This is because a release agent (wax) having the same function as the release agent fine particle dispersion [W] is included in the layer. On the other hand, since the amorphous polyester resin used for the production of toners [1] to [6] cannot contain a release agent (wax), a separate release agent (wax) is required. The mold fine particle dispersion [W] is contained.

<Toner Preparation Example 8>
In Toner Preparation Example 1, toner [8] was prepared in the same manner except that the crystalline polyester resin fine particle dispersion [C1] was used instead of the wax layer-forming crystalline polyester resin fine particle dispersion [WC1]. did. The volume-based median diameter of the obtained toner [8] was 6.5 μm. When the TEM observation of the crystalline polyester domain of the toner particles [8] was performed, the domain diameter could not be confirmed.

<Toner Preparation Example 9>
Toner [9] was the same as Example 1 except that a crystalline polyester resin fine particle dispersion (WC7) by seed polymerization was used instead of the wax layer-forming crystalline polyester resin fine particle dispersion [WC1]. Was made. The volume-based median diameter of the obtained toner [9] was 6.5 μm. When the TEM observation of the crystalline polyester domain of the toner particles [9] was performed, the domain diameter could not be confirmed.

<Production of developer>
A ferrite carrier having a volume-based median diameter of 60 μm coated with a silicone resin is mixed with the obtained toners [1] to [9] using a V-type mixer so that the toner concentration becomes 6% by mass. As a result, developers [1] to [9] were obtained.

<Evaluation>
(1) Domain diameter and number of domains of crystalline resin in toner The formation of domains of crystalline resin in toner particles means that the cross section of toner particles dyed with heavy metal oxide such as ruthenium tetroxide is transmitted. It can confirm by observing using an electron microscope (TEM). Specifically, for example, when the crystalline resin is a crystalline polyester resin and the amorphous resin is an amorphous polyester resin, the crystalline polyester resin is not dyed and the amorphous polyester resin is dyed. Therefore, it can be identified. The cross section of the toner particles observed with a TEM is preferably the cross section of the maximum area of the toner particles. Dyeing of toner particles with ruthenium tetroxide can be carried out by various known methods. Specifically, for example, the toner can be dyed by contacting with a 0.5% by weight aqueous solution of ruthenium tetroxide.

  As described above, the domain diameter of the crystalline resin in the toner is obtained by taking a cross-sectional image (magnification of 10,000 times) of the toner particles observed in the TEM and taking in the “Luzex image analyzer” (manufactured by Nireco) Domain observation of 0.1 to 0.9 μm in the cross section was performed. The observation was made in the same manner for five toners.

  The diameter (domain diameter) of the crystalline resin domain constituting the toner particles according to the present invention is preferably 0.1 to 0.9 μm, more preferably 0.2 to 0.5 μm.

  When the domain diameter is in the above range, the desired low-temperature fixability and long-term storage stability can be reliably achieved. When the domain diameter is excessively small, aggregation and fusion of toner particles occur due to the progress of compatibility between the crystalline resin constituting the domain and the amorphous resin constituting the matrix during storage of the toner, As a result, long-term storage stability may not be obtained. In addition, when the domain diameter is excessive, the compatibility between the crystalline resin constituting the domain and the amorphous resin constituting the matrix does not proceed sufficiently at the time of heat fixing, and the desired low-temperature fixability can be obtained. There is a risk of not.

(2) Low-temperature fixability As an image forming apparatus, in a commercially available multifunction machine “bizhub PRO C6500” (manufactured by Konica Minolta Business Technologies), the surface temperature of the fixing heating member in the fixing device of the hot roll fixing method is 80 to 150 ° C. Weighing is performed under the environment of normal temperature and humidity (temperature 20 ° C., humidity 50% RH) using the developer [1] to [9] modified so that it can be changed within the range. A fixing experiment in which a solid image with an image density of 0.8 is fixed on 350 g of paper while changing the set fixing temperature (surface temperature of the fixing heating member) from 80 ° C. to 150 ° C. in increments of 5 ° C. Repeatedly.

  The obtained solid image is folded by a folding machine so that a load is applied to the solid image, and air with a pressure of 0.35 MPa is blown onto the solid image. The fixing temperature in the fixing experiment of rank 3 was defined as the lower limit fixing temperature.

  A case where the temperature is lower than 120 ° C. is determined as an acceptable level, and a case where the temperature is lower than 110 ° C. is determined to be extremely good.

-Evaluation criteria-
Rank 1: There is a large separation in the image (there is also a portion other than the crease)
Rank 2: Thick linear peeling according to the fold Rank 3: Thin linear peeling according to the fold Rank 4: Partial peeling according to the fold Rank 5: No peeling at the fold .

(3) Long-term storage stability-Heat cycle test assuming cargo ship transportation-
Each of the toners [1] to [9] was filled with 50 g of toner in a polyethylene bottle, closed with a lid, and shaken 50 times with a “Tap Denser KYT-2000” (manufactured by Seishin Enterprise). Next, a polyethylene bottle containing 50 g of toner was placed in a thermostatic bath, and a heat cycle test was performed assuming dry container cargo ship transportation (on-deck top loading).

  Specifically, after storing for 24 hours in an environment at a temperature of 30 ° C., the temperature is increased from 30 ° C. to 60 ° C. over 6 hours and then returned to 60 ° C. to 30 ° C. over 6 hours 90 times. went.

  After performing this heat cycle test, place the toner on a 48 mesh (350 μm mesh) sieve with care not to crush it, set the sieve on a “powder tester” (manufactured by Hosokawa Micron), and press the bar. After fixing with a knob nut, adjusting the vibration intensity to a feed width of 1 mm and applying vibration for 10 seconds, the amount of residual toner remaining on the sieve was measured, and the toner aggregation rate was calculated and evaluated by the following formula (1). .

  When the toner aggregation rate is 20% by mass or less, it is determined as an acceptable level, and when it is less than 15% by mass, it is determined that the long-term storage stability is extremely good.

11 toner particles,
12 crystalline resin fine particles,
13 Wax layer,
13 'wax 14 vinyl resin layer,
14 'vinyl monomer,
15 Wax layer forming crystalline resin fine particles,
16 Amorphous resin (matrix),
17 Wax-containing monomer solution.

Claims (2)

A method for producing an electrostatic charge image developing toner comprising toner particles containing an amorphous resin, a crystalline resin and a wax,
(A) a step of emulsifying and dispersing crystalline resin fine particles in an aqueous medium to prepare a resin fine particle dispersion;
(B) a step of dissolving a wax in a vinyl monomer at a temperature equal to or higher than a melting point to prepare a monomer solution;
(C) mixing the resin fine particle dispersion and the monomer solution to form monomer droplets containing the resin fine particles;
(D) polymerizing the monomer droplets;
(E) a step of polymerizing the monomer droplets and then holding the crystalline resin and the wax at a temperature equal to or higher than the melting point to form wax layer-forming crystalline resin fine particles;
(F) a step of forming toner particles by agglomerating and fusing the wax layer-forming crystalline resin fine particles and fine particles comprising an amorphous resin;
And a method for producing a toner for developing an electrostatic charge image.   The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein the crystalline resin is a crystalline polyester.

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