JP2019158943A - Electrostatic image development toner - Google Patents

Abstract

To provide an electrostatic image development toner which suppresses electrostatic adhesion.SOLUTION: An electrostatic image development toner of the present invention contains toner particles comprising toner base particles (10) having an external additive covering surfaces thereof. Each toner base particle (10) comprises: a toner base particle precursor (11) containing a non-crystalline resin (101a) and a crystalline polyester resin (101b); and a plurality of protrusions (12) formed on a surface of the toner base particle precursor (11). The external additive contains alumina particles.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electrostatic image developing toner, and more particularly to an electrostatic image developing toner that suppresses electrostatic sticking.

  2. Description of the Related Art Conventionally, there has been a demand for speeding up and energy saving of copying machines, and development of an electrostatic charge image developing toner (hereinafter also simply referred to as toner) excellent in low-temperature fixability has been developed. In such a toner, it is necessary to lower the melting temperature and melt viscosity of the binder resin, and a toner having improved low-temperature fixability by adding a crystalline resin such as a crystalline polyester resin has been proposed. Yes. However, when a crystalline polyester resin is added to the toner, electric resistance tends to decrease and chargeability tends to deteriorate.

  By the way, as external additives for toner, generally, fine powders of inorganic oxides, and in many cases, silica particles, titania particles, and alumina particles are exemplified. The role of the external additive is to improve chargeability and fluidity. However, since the silica particles have high negative chargeability, the toner charge amount is excessively increased particularly in a low temperature and low humidity environment. In addition, titania particles have low resistance, and when titania particles are used in toner added with a crystalline polyester resin, the resistance tends to be lower and the charging property tends to deteriorate.In addition, since titania particles have low hardness, When printing a large number of sheets, the titania particles tend to be separated from the toner base particles.

In the field of production printing, many images of the entire paper with a large amount of adhesion, such as posters, are often output by double-sided printing. In double-sided printing, the second side of the image fixed on the first side is printed. Charges due to a transfer current during transfer accumulate, and the charges are attenuated when the lower roller is touched during fixing of the second surface.
However, if there is a gap in the image fixed on the first surface, or if the external additive in the image has decreased due to separation, the charge on the image on the first surface escapes when the lower roller is touched. There is a problem that the documents remain without being cut and the documents are electrostatically stuck on the paper discharge tray (see, for example, Patent Documents 1 and 2).

JP 2017-3901 A Japanese Patent No. 5831078

  The present invention has been made in view of the above problems and situations, and a problem to be solved is to provide a toner for developing an electrostatic image that suppresses electrostatic sticking.

  In order to solve the above problems, the present inventor, in the process of examining the cause of the above problems, the toner base particles include an amorphous resin and a crystalline polyester resin, and the surface has convex portions. The inventors have found that a plurality of formed external additives containing alumina particles can provide a toner for developing an electrostatic image that suppresses electrostatic sticking, and have reached the present invention.

  That is, the said subject which concerns on this invention is solved by the following means.

1. A toner for developing an electrostatic image containing toner particles having an external additive on the surface of the toner base particles,
The toner base particles include a toner base particle precursor containing an amorphous resin and a crystalline polyester resin, and a plurality of protrusions formed on the surface of the toner base particle precursor.
An electrostatic charge image developing toner comprising alumina particles as the external additive.

  2. 2. The electrostatic image developing toner according to item 1, wherein the convex portion contains an amorphous polyester resin.

  3. 3. The electrostatic image developing toner according to item 1 or 2, wherein an average long side length of the convex portion is in a range of 100 to 300 nm.

  4). The toner for developing an electrostatic charge image according to any one of Items 1 to 3, wherein an average interval between the convex portions is in a range of 20 to 200 nm.

  5. Item 5. The electrostatic image developing toner according to any one of Items 1 to 4, wherein the alumina particles have a number average particle size in a range of 5 to 60 nm.

  6). The content of the alumina particles in the toner particles is in the range of 0.1 to 2.0 parts by mass with respect to 100 parts by mass of the toner base particles. The toner for developing an electrostatic image according to any one of the above.

  7). The content of the crystalline polyester resin is in the range of 3 to 20% by mass with respect to the total mass (100% by mass) of the resin contained in the toner base particles. The electrostatic image developing toner according to any one of Items 6 to 6.

  By the above means of the present invention, it is possible to provide a toner for developing an electrostatic charge image with suppressed electrostatic sticking.

  The expression mechanism / action mechanism of the effect of the present invention is not clear, but is presumed as follows.

  The electrostatic sticking occurs when the charge charged in the transfer process on the second surface remains without being discharged even by the temperature of the lower roller. The charge charged in the transfer process on the second surface is the same as the charge after output because all of the charged charge moves in the image (toner layer) on the first surface when the temperature of the lower roller is applied in the fixing process. If it does not remain, electrostatic sticking will not occur.

  Therefore, in the present invention, electrostatic sticking is suppressed by including alumina particles in the external additive. Since the alumina particles are harder than the titania particles (Mohs hardness: alumina: 9, titania: 6), it becomes possible to strongly adhere the alumina particles to the toner base particles, and the alumina particles are not detached even when a large number of sheets are printed. The amount of adhesion to the toner base particles can be maintained. As a result, the number of external additives in the image is increased, and it is estimated that electrostatic sticking can be improved.

In addition, by using toner base particles containing a crystalline polyester resin, the toner particles can be quickly melted and fixed at such a temperature in the fixing step, and the arrangement state of the surrounding external additives is not destroyed. I guess it can be fixed.
Further, the convex portions formed on the surface of the toner base particle precursor are easily crushed in a state where the toner particles are engaged with each other (see FIG. 1), and the closeness between the toner particles is increased, and the image (toner layer) is increased. It is presumed that there is no void inside and the resin is filled with resin, and the presence of the external additive (alumina particles) makes it easier for the charged charge to move.

FIG. 3 is an image diagram showing a schematic configuration of toner base particles according to the present invention. SEM image of toner base particles according to the present invention FIG. 3 is an image diagram showing a schematic configuration of toner base particles according to the present invention. Explanatory drawing for demonstrating the average long side length and average space | interval of the convex part of the toner base particle precursor surface which concerns on this invention

  The electrostatic image developing toner of the present invention comprises a toner base particle precursor in which the toner base particles contain an amorphous resin and a crystalline polyester resin, and a plurality of convex portions formed on the surface of the toner base particle precursor. , And alumina particles are included as an external additive. This feature is a technical feature common to the inventions according to the following embodiments.

  As an embodiment of the present invention, the convex portion preferably contains an amorphous polyester resin. Since the amorphous polyester resin is not compatible with the crystalline polyester resin, a convex portion can be effectively formed on the surface of the toner base particle precursor.

  Further, from the viewpoint of increasing the closeness between the toner particles at the time of fixing, it is preferable that the average long side length of the convex portion is in the range of 100 to 300 nm.

  Moreover, it is preferable that the average space | interval of a convex part exists in the range of 20-200 nm. It is preferable that the convex portions are present in a uniform manner without uneven distribution. By setting the average interval of the convex portions within the above range, the closeness of the toner particles during fixing can be increased.

  The number average particle diameter of the alumina particles is preferably in the range of 5 to 60 nm because the contact area between the toner base particles and the alumina particles can be increased and more strongly adhered.

  Further, from the viewpoint of facilitating movement of the charged charge in the fixed image, the content of alumina particles in the toner particles is within the range of 0.1 to 2.0 parts by mass with respect to 100 parts by mass of the toner base particles. It is preferable that

  Further, from the viewpoint of improving the fixing property and heat resistance, the content of the crystalline polyester resin is in the range of 3 to 20% by mass with respect to the total mass (100% by mass) of the resin contained in the toner base particles. It is preferable.

  Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In addition, in this application, "-" showing a numerical range is used by the meaning containing the numerical value described before and behind that as a lower limit and an upper limit.

<Toner for electrostatic image development>
The electrostatic image developing toner of the present invention (hereinafter also simply referred to as toner) is an electrostatic image developing toner containing toner particles having an external additive on the surface of the toner base particles. A toner base particle precursor containing an amorphous resin and a crystalline polyester resin, and a plurality of protrusions formed on the surface of the toner base particle precursor, and containing alumina particles as an external additive This is a technical feature.

  In the present invention, toner base particles added with an external additive are referred to as toner particles, and an aggregate of toner particles is referred to as toner. The toner base particles can be used as toner particles as they are, but in the present invention, toner base particles added with an external additive are used as toner particles.

<Toner base particles>
The toner base particles according to the present invention include a toner base particle precursor containing an amorphous resin and a crystalline polyester resin as a binder resin, and a plurality of protrusions formed on the surface of the toner base particle precursor. It is configured to include.
For example, as shown in FIGS. 1 and 2, the toner base particle 10 includes a toner base particle precursor 11 and a plurality of convex portions 12 formed on the surface of the toner base particle precursor 11. Has been.
The toner base particle precursor 11 contains a toner base particle precursor resin 101 including an amorphous resin 101a and a crystalline polyester resin 101b.
The convex part 12 is comprised including resin for convex parts.

Here, the crystalline (polyester) resin refers to a resin having a clear endothermic peak at the melting point, that is, when the temperature is increased, in an endothermic curve obtained by differential scanning calorimetry (DSC). A clear endothermic peak means a peak having a half-value width of 15 ° C. or less in an endothermic curve when the temperature is increased at a rate of temperature increase of 10 ° C./min.
On the other hand, the amorphous resin shows a baseline curve indicating that the glass transition has occurred in the endothermic curve obtained when the differential scanning calorimetry is performed as described above, but the above-mentioned clear endothermic A resin with no peak.

(Amorphous resin)
The toner base particles according to the present invention contain an amorphous resin as a binder resin. As an amorphous resin, a well-known thing can be used. Specific examples thereof include vinyl resin, urethane resin, urea resin, and polyester resin. Of these, vinyl resins are preferred because of the small variation due to environmental differences.

The vinyl resin is not particularly limited as long as a vinyl compound is polymerized, and examples thereof include (meth) acrylic acid ester resins, styrene / (meth) acrylic acid ester resins, and ethylene / vinyl acetate resins.
These may be used individually by 1 type and may be used in combination of 2 or more type.

  Among the vinyl resins, styrene / (meth) acrylic acid ester resins are preferable from the viewpoint of plasticity during heat fixing. Therefore, styrene / (meth) acrylic ester resin (hereinafter also referred to as styrene / (meth) acrylic resin) as an amorphous resin will be described below.

The styrene / (meth) acrylic resin is formed by addition polymerization of at least an aromatic vinyl monomer and a (meth) acrylic acid ester monomer. Aromatic vinyl monomers include those having a known side chain or functional group in the styrene structure in addition to styrene represented by the structural formula of CH ₂ ═CH—C ₆ H ₅ . In addition, the (meth) acrylic acid ester monomer here refers to an acrylic acid ester derivative or a methacrylic acid ester other than the acrylic acid ester or methacrylic acid ester represented by CH ₂ ═CHCOOR (R represents an alkyl group). It includes those having a known side chain or functional group in the structure of a methacrylic acid ester derivative or the like. In the present invention, the (meth) acrylic acid ester monomer is a general term for an acrylic acid ester monomer and a methacrylic acid ester monomer.

  Examples of aromatic vinyl monomers and (meth) acrylic acid ester monomers capable of forming styrene / (meth) acrylic resins are shown below.

Examples of the aromatic vinyl monomer include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, p-ethylstyrene, and 2,4-dimethylstyrene. , P-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, and the like.
These aromatic vinyl monomers may be used alone or in combination of two or more.

Specific examples of the (meth) acrylic acid ester monomer include, for example, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate. Acrylate monomers such as stearyl acrylate, lauryl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, Stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, diethylaminoethyl meta Relate, methacrylic acid esters such as dimethyl aminoethyl methacrylate.
These (meth) acrylic acid ester monomers may be used alone or in combination of two or more.

  It is preferable that the content rate of the structural unit derived from the aromatic vinyl monomer in a styrene (meth) acrylic resin is in the range of 40-90 mass% with respect to the whole quantity of the said resin, for example. Moreover, it is preferable that the content rate of the structural unit derived from the (meth) acrylic acid ester monomer in the said resin exists in the range of 10-60 mass% with respect to the whole quantity of the said resin, for example.

Furthermore, the styrene / (meth) acrylic resin may contain the following monomer compounds in addition to the aromatic vinyl monomer and the (meth) acrylic acid ester monomer. For example, compounds having a carboxy group such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, cinnamic acid, fumaric acid, maleic acid monoalkyl ester, itaconic acid monoalkyl ester; 2-hydroxyethyl (meth) acrylate, 2 -Compounds having a hydroxy group such as hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate Is mentioned.
These monomer compounds may be used alone or in combination of two or more.

  It is preferable that the content rate of the structural unit derived from the said monomeric compound in a styrene (meth) acrylic resin exists in the range of 0.5-20 mass% with respect to the whole quantity of the said resin, for example.

  The weight average molecular weight (Mw) of the styrene / (meth) acrylic resin is preferably in the range of 10,000 to 100,000, for example.

In this invention, the weight average molecular weight (Mw) of resin is calculated | required from the molecular weight distribution measured by the gel permeation chromatography (GPC: Gel Permeation Chromatography).
Specifically, first, a measurement sample is added to tetrahydrofuran so as to have a concentration of 1 mg / mL, followed by a dispersion treatment at room temperature for 5 minutes using an ultrasonic disperser, and then a membrane filter having a pore size of 0.2 μm. To prepare a sample solution. For example, using GPC apparatus HLC-8120GPC (manufactured by Tosoh Corporation) and a column (“TSKgel guardcolumn SuperHZ-L” and “TSKgel SuperHZM-M” (manufactured by Tosoh Corporation)), while maintaining the column temperature at 40 ° C., the carrier solvent Then, tetrahydrofuran is flowed at a flow rate of 0.2 mL / min. 10 μL of the prepared sample solution is injected into the GPC apparatus together with the carrier solvent, the sample is detected using a refractive index detector (RI detector), and a calibration curve measured using monodisperse polystyrene standard particles is used. Calculate the molecular weight distribution of the sample. The calibration curves have molecular weights of 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , 3.9 × 10, respectively. It is prepared by measuring 10 standard polystyrene particles (manufactured by Pressure Chemical) that are ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ .

  The method for producing the styrene / (meth) acrylic resin is not particularly limited, and any polymerization initiator such as peroxide, persulfide, persulfate, azo compound or the like usually used for the polymerization of the above monomers is used. , Bulk polymerization, solution polymerization, emulsion polymerization method, miniemulsion method, dispersion polymerization method and the like. Moreover, the chain transfer agent generally used can be used in order to adjust molecular weight. The chain transfer agent is not particularly limited, and examples thereof include alkyl mercaptans such as n-octyl mercaptan, mercapto fatty acid esters, and the like.

  The glass transition temperature (Tg) of the amorphous resin is not particularly limited, but from the viewpoint of reliably obtaining fixing properties such as low-temperature fixing properties and heat resistance such as heat-resistant storage properties and blocking resistance, for example, 25 to 60 It is preferably within the range of ° C.

Furthermore, in order to reduce the mechanical strength of the toner and suppress the excessive burying of the external additive, it is preferable to use a polyester resin together with a vinyl resin as an amorphous resin.
As an amorphous polyester resin, the thing similar to the amorphous polyester resin contained in the convex part mentioned later is mentioned.

(Crystalline polyester resin)
The toner base particles according to the present invention contain a crystalline polyester resin in addition to an amorphous resin as a binder resin.

  The crystalline polyester resin is a crystalline resin among polyester resins obtained by a polymerization reaction of a divalent or higher carboxylic acid (polyvalent carboxylic acid) monomer and a divalent or higher alcohol (polyhydric alcohol) monomer. Refers to a resin showing

Examples of the polyvalent carboxylic acid monomer that can be used for the synthesis of the crystalline polyester resin include oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, n-dodecyl succinic acid, and 1,10-decane. Saturated aliphatic dicarboxylic acids such as dicarboxylic acid (dodecanedioic acid), 1,12-dodecanedicarboxylic acid (tetradecanedioic acid), alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, fragrances such as phthalic acid, isophthalic acid, terephthalic acid And trivalent or higher polyvalent carboxylic acids such as aromatic dicarboxylic acid, trimellitic acid and pyromellitic acid, anhydrides of these carboxylic acid compounds, alkyl esters having 1 to 3 carbon atoms, and the like.
These may be used individually by 1 type and may be used in combination of 2 or more type.

Examples of the polyhydric alcohol monomer that can be used for the synthesis of the crystalline polyester resin include 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1, Aliphatic diols such as 6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, neopentyl glycol, 1,4-butenediol, glycerin, pentaerythritol, trimethylolpropane And trihydric or higher polyhydric alcohols such as sorbitol.
These may be used individually by 1 type and may be used in combination of 2 or more type.

  The content of the crystalline polyester resin is based on the total mass (100% by mass) of the resin contained in the toner base particles (including the resin (resin for convex part) contained in the convex part on the surface of the toner base particle precursor). And it is preferable that it exists in the range of 3-20 mass%. If the content of the crystalline polyester resin is 3% by mass or more, good fixability can be obtained, and if it is 20% by mass or less, the abundance on the surface of the toner base particles is reduced and the heat resistance is improved.

(Glass transition point and softening point)
The glass transition point (Tg) of the toner base particle precursor resin is preferably in the range of 40 to 60 ° C.
The glass transition point of the toner base particle precursor resin is a value measured by a method (DSC method) defined in ASTM (American Society for Testing and Materials) D3418-82.
Specifically, 3.0 mg of a sample was precisely weighed to two digits after the decimal point, sealed in an aluminum pan, and set in a sample holder of a differential scanning calorimeter “Diamond DSC” (Perkin Elmer). The reference uses an empty aluminum pan, and the temperature control of temperature increase / decrease / temperature increase is performed at a temperature increase rate of 10 ° C./min and a temperature decrease rate of 10 ° C./min within a measurement temperature range of 0 to 200 ° C. The analysis was performed based on the data at the second temperature increase. The glass transition point is defined as the value of the intersection of the extension line of the base line before the rise of the first endothermic peak and the tangent line indicating the maximum slope between the rising portion of the first endothermic peak and the peak apex.

The softening point of the toner base particle precursor resin is preferably in the range of 80 to 130 ° C.
The softening point (Tsp) of the toner base particle precursor resin is a value measured as follows.
First, in an environment of 20 ° C. ± 1 ° C. and 50% ± 5% RH, 1.1 g of resin is placed in a petri dish and flattened and left for 12 hours or more. ) Was pressed with a force of 3820 kg / cm ² for 30 seconds to produce a cylindrical molded sample having a diameter of 1 cm. Next, this molded sample was subjected to a load of 196 N (20 kgf), a starting temperature of 60 ° C. and a preheating by a flow tester “CFT-500D” (manufactured by Shimadzu Corporation) in an environment of 24 ° C. ± 5 ° C. and 50% ± 20% RH. Extruding from the hole of the cylindrical die (1 mm diameter x 1 mm) using a piston with a diameter of 1 cm from the end of preheating under the condition of a heating rate of 6 ° C / min for 300 seconds, The offset method temperature T _offset measured with an offset value of 5 mm is taken as the softening point of the resin.

(Method for producing resin for toner base particle precursor)
The toner base particle precursor resin is preferably prepared by an emulsion polymerization method. Emulsion polymerization can be obtained by dispersing and polymerizing a polymerizable monomer such as styrene or acrylate in an aqueous medium. In order to disperse the polymerizable monomer in the aqueous medium, a surfactant is preferably used, and a polymerization initiator and a chain transfer agent can be used for the polymerization.

(1) Polymerization initiator The polymerization initiator used for the polymerization of the toner base particle precursor resin is not particularly limited, and known ones can be used. Specifically, for example, hydrogen peroxide, acetyl peroxide, cumyl peroxide, tert-butyl peroxide, propionyl peroxide, benzoyl peroxide, chlorobenzoyl peroxide, dichlorobenzoyl peroxide, bromomethylbenzoyl peroxide, Lauroyl oxide, ammonium persulfate, sodium persulfate, potassium persulfate, diisopropyl peroxycarbonate, tetralin hydroperoxide, 1-phenyl-2-methylpropyl-1-hydroperoxide, pertriphenylacetic acid-tert-hydroperoxide, performic acid-tert -Butyl, peracetic acid-tert-butyl, perbenzoic acid-tert-butyl, perphenylacetic acid-tert-butyl, permethoxyacetic acid-tert-butyl, per-N- (3-toluyl) palmitic acid-tert-butyl, etc. Peroxides; 2, '-Azobis (2-aminodipropane) hydrochloride, 2,2'-azobis- (2-aminodipropane) nitrate, 1,1'-azobis (1-methylbutyronitrile-3-sulfonic acid sodium salt), Examples include azo compounds such as 4,4'-azobis-4-cyanovaleric acid and poly (tetraethylene glycol-2,2'-azobisisobutyrate).

  The addition amount of the polymerization initiator varies depending on the desired molecular weight and molecular weight distribution, but specifically, it is preferably added in the range of 0.1 to 5.0% by mass with respect to the polymerizable monomer.

(2) Chain transfer agent In the production of the toner base particle precursor resin, a chain transfer agent may be added together with the polymerizable monomer. The molecular weight of the polymer can be controlled by adding a chain transfer agent. In the polymerization step of polymerizing the above-mentioned aromatic vinyl monomer and (meth) acrylic acid ester monomer, it is generally used for the purpose of adjusting the molecular weight of the styrene / acrylic polymer segment. Chain transfer agents can be used. The chain transfer agent is not particularly limited, and examples thereof include alkyl mercaptans and mercapto fatty acid esters.

  Although the addition amount of a chain transfer agent changes with desired molecular weights or molecular weight distribution, specifically, it is preferable to add in the range of 0.1-5.0 mass% with respect to a polymerizable monomer.

(3) Surfactant When the toner base particle precursor resin is dispersed in an aqueous medium and polymerized by an emulsion polymerization method, a dispersion stabilizer is usually added to prevent aggregation of the dispersed droplets. As the dispersion stabilizer, a known surfactant can be used, and a dispersion stabilizer selected from a cationic surfactant, an anionic surfactant, a nonionic surfactant and the like can be used. Two or more of these surfactants may be used in combination. The dispersion stabilizer can also be used in a dispersion liquid such as a colorant and an offset preventing agent.

  Specific examples of the cationic surfactant include dodecyl ammonium bromide, dodecyl trimethyl ammonium bromide, dodecyl pyridinium chloride, dodecyl pyridinium bromide, and hexadecyl trimethyl ammonium bromide.

  Specific examples of nonionic surfactants include dodecyl polyoxyethylene ether, hexadecyl polyoxyethylene ether, norylphenyl polyoxyethylene ether, lauryl polyoxyethylene ether, sorbitan monooleate polyoxyethylene ether, styrylphenyl poly Examples thereof include oxyethylene ether and monodecanoyl sucrose.

  Specific examples of the anionic surfactant include aliphatic soaps such as sodium stearate and sodium laurate, sodium lauryl sulfate, sodium dodecylbenzene sulfonate, and polyoxyethylene (2) sodium lauryl ether sulfate. .

  If necessary, a release agent, a colorant, a charge control agent, and the like can be added to the toner base particle precursor according to the present invention.

(Release agent)
Examples of the release agent contained in the toner base particle precursor according to the present invention include wax.
Examples of the wax include low molecular weight polyethylene wax, low molecular weight polypropylene wax, Fischer-Tropsch wax, microcrystalline wax, hydrocarbon wax such as paraffin wax, carnauba wax, pentaerythritol behenate, behenyl behenate, And ester waxes such as behenyl acid.
These can be used alone or in combination of two or more.

As the wax, it is preferable to use a wax having a melting point in the range of 50 to 95 ° C. from the viewpoint of reliably obtaining low-temperature fixability and releasability of the toner.
The content ratio of the wax is preferably in the range of 2 to 20% by mass, more preferably in the range of 3 to 18% by mass, and further preferably 4 to 15% by mass, based on the total amount of the resin for the toner base particle precursor. %.

(Coloring agent)
As the colorant when the toner base particle precursor is configured to contain a colorant, carbon black, a magnetic material, a dye, a pigment, or the like can be arbitrarily used.

As carbon black, channel black, furnace black, acetylene black, thermal black, lamp black and the like can be used.
As the magnetic material, ferromagnetic metals such as iron, nickel and cobalt, alloys containing these metals, and compounds of ferromagnetic metals such as ferrite and magnetite can be used.

Examples of the pigment include C.I. I. Pigment Red 2, 3, 5, 7, 15, 16, 48: 1, 48: 3, 53: 1, 57: 1, 81: 4, 122, 123, 139, 144, 149, 166, 177, 178, 208, 209, 222, C.I. I. Pigment Orange 31 and 43, C.I. I. Pigment Yellow 3, 9, 14, 17, 35, 36, 65, 74, 83, 93, 94, 98, 110, 111, 138, 139, 153, 155, 180, 181, 185, C.I. I. Pigment green 7, C.I. I. Pigment Blue 15: 3, 15: 4, 60, and phthalocyanine pigments whose central metal is zinc, titanium, magnesium, or the like, and mixtures thereof can also be used.
Examples of the dye include C.I. I. Solvent Red 1, 3, 14, 17, 17, 22, 22, 49, 51, 52, 58, 63, 87, 111, 122, 127, 128, 131, 145, 146, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 176, 179, pyrazolotriazole Azo dyes, pyrazolotriazole azomethine dyes, pyrazolone azo dyes, pyrazolone azomethine dyes, C.I. I. Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 60, 70, 93, 95, and the like, and mixtures thereof can also be used.

  The content ratio of the colorant is preferably in the range of 1 to 30% by mass, more preferably in the range of 2 to 20% by mass with respect to the total mass of the toner base particle precursor resin.

(Charge control agent)
Various known materials can be used as the charge control agent.
As the charge control agent, various known compounds that can be dispersed in an aqueous medium can be used. Specifically, nigrosine dyes, metal salts of naphthenic acid or higher fatty acids, alkoxylated amines, fourth compounds. Examples include quaternary ammonium salt compounds, azo metal complexes, salicylic acid metal salts or metal complexes thereof.

  The content ratio of the charge control agent is preferably in the range of 0.1 to 10.0% by mass, more preferably 0.5 to 5.0% by mass with respect to the total amount of the toner base particle precursor resin. Within range.

(Convex)
The material constituting the plurality of convex portions formed on the surface of the toner base particle precursor (resin for convex portions) is not particularly limited as long as it can form convex portions on the surface of the toner base particle precursor, but is not limited. A crystalline polyester resin is preferred.

  The amorphous polyester resin is produced by polycondensation reaction using a polyvalent carboxylic acid monomer (derivative) and a polyhydric alcohol monomer (derivative) as raw materials in the presence of an appropriate catalyst.

  Examples of the polyvalent carboxylic acid monomer derivative include alkyl esters, acid anhydrides, and acid chlorides of the polyvalent carboxylic acid monomer. Examples of the polyhydric alcohol monomer derivative include esters of the polyhydric alcohol monomer and hydroxycarboxylic acid. An acid can be used.

  Examples of the polyvalent carboxylic acid monomer include oxalic acid, succinic acid, maleic acid, adipic acid, β-methyladipic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, Fumaric acid, citraconic acid, diglycolic acid, cyclohexane-3,5-diene-1,2-dicarboxylic acid, malic acid, citric acid, hexahydroterephthalic acid, malonic acid, pimelic acid, tartaric acid, mucic acid, phthalic acid , Isophthalic acid, terephthalic acid, tetrachlorophthalic acid, chlorophthalic acid, nitrophthalic acid, p-carboxyphenylacetic acid, p-phenylenediacetic acid, m-phenylenediglycolic acid, p-phenylenediglycolic acid, o-phenylenediglycolic acid , Diphenylacetic acid, diphenyl-p, p ′ Divalent carboxylic acids such as dicarboxylic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, anthracene dicarboxylic acid, dodecenyl succinic acid, trimellitic acid, pyromellitic Examples thereof include trivalent or higher carboxylic acids such as acid, naphthalenetricarboxylic acid, naphthalenetetracarboxylic acid, pyrenetricarboxylic acid, and pyrenetetracarboxylic acid. As the polyvalent carboxylic acid monomer, for example, unsaturated aliphatic dicarboxylic acids such as fumaric acid, maleic acid, and mesaconic acid are preferably used. In the present invention, an anhydride of a dicarboxylic acid such as maleic anhydride can also be used.

  Examples of the polyhydric alcohol monomer include ethylene glycol, propylene glycol, butanediol, diethylene glycol, hexanediol, cyclohexanediol, octanediol, decanediol, dodecanediol, ethylene oxide adduct of bisphenol A, and propylene oxide adduct of bisphenol A. And divalent alcohols such as glycerin, pentaerythritol, hexamethylol melamine, hexaethylol melamine, tetramethylol benzoguanamine, tetraethylol benzoguanamine and the like.

  Among these, it is preferable that the convex portion on the surface of the toner base particle precursor contains an amorphous polyester resin containing structural units of bisphenol A propylene oxide adduct and bisphenol A ethylene oxide adduct. Thereby, it can control so that it may not be compatible with crystalline polyester resin, and a convex part can be more effectively formed in the toner base particle precursor surface.

  Further, as the amorphous polyester resin according to the present invention, a vinyl polymer segment composed of a styrene / acrylic polymer and a polyester polymer segment composed of an amorphous polyester resin are both reactive. A hybrid amorphous polyester resin bonded via a monomer can also be used, and it is preferable that a constituent unit of the hybrid amorphous polyester resin contains a bisphenol A propylene oxide adduct and a bisphenol A ethylene oxide adduct. Thereby, the abundance ratio of the crystalline resin on the surface of the toner base particle precursor can be reduced, and the heat resistance and fluidity can be improved. This is because the vinyl resin part of the same resin as the toner base particle precursor is more easily oriented on the inner side, and the polyester resin part of the toner base particle precursor and the different resin is more easily oriented on the outer side, leading to dispersibility of the crystalline resin. It is presumed that the influence of this has been reduced. In addition, due to the compatibility of the vinyl resin part of the hybrid amorphous polyester resin, the convex part is difficult to be detached from the toner base particle precursor, and the fixing property, heat resistance, fluidity and durability can be ensured.

  For example, as shown in FIG. 3, the convex portion 12 of the hybrid amorphous polyester resin 102 has a vinyl polymer segment 102a oriented inside the toner base particles and a polyester polymer segment 102b oriented outside the toner base particles. It is formed like this.

The vinyl polymer segment in the hybrid amorphous polyester resin refers to a polymer portion obtained by polymerizing an aromatic vinyl monomer and a (meth) acrylate monomer.
The content ratio of the vinyl polymer segment is preferably in the range of 5 to 30% by mass and more preferably in the range of 10 to 20% by mass with respect to the total mass of the hybrid amorphous polyester resin. .
When the hybrid amorphous polyester resin contains the vinyl polymer segment within the range of 5 to 30% by mass, the detachment of the convex portion hardly occurs and the durability is improved. Further, when the toner is produced, coalescence between the convex portions hardly occurs, and the crystalline polyester resin is hardly exposed on the surface of the toner base particle precursor, and a sufficient effect as the convex portions can be obtained.

  The hybrid amorphous polyester resin preferably contains a polyester-based polymer segment in the range of 95 to 50% by mass.

  The content ratio of the vinyl polymer segment in the hybrid amorphous polyester resin is specifically the total mass of the resin material used for synthesizing the hybrid amorphous polyester resin, that is, the polyester polymer segment. A polymerizable monomer forming an unmodified polyester resin, an aromatic vinyl monomer and a (meth) acrylate monomer serving as a vinyl polymer segment, and both reactions for bonding them together It means the ratio of the mass of the aromatic vinyl monomer and the (meth) acrylic acid ester monomer forming the vinyl polymer segment to the total mass of the polymerizable monomers.

  In addition, an unsaturated aliphatic dicarboxylic acid is used as a polyvalent carboxylic acid monomer to form a polyester-based polymer segment of the hybrid amorphous polyester resin, and the unsaturated aliphatic dicarboxylic acid is added to the polyester-based polymer segment. It is preferable that the derived structural unit is contained. An unsaturated aliphatic dicarboxylic acid refers to a chain dicarboxylic acid having a vinylene group in the molecule. Here, the structural unit means a unit of molecular structure derived from a monomer in the resin.

  Content ratio of structural unit derived from unsaturated aliphatic dicarboxylic acid in structural unit derived from polyvalent carboxylic acid monomer constituting polyester-based polymerized segment (hereinafter also referred to as “specific unsaturated dicarboxylic acid content ratio”) .) Is preferably in the range of 18 to 75 mol%, more preferably in the range of 25 to 60 mol%, and particularly preferably in the range of 30 to 60 mol%.

  The structural unit derived from the unsaturated aliphatic dicarboxylic acid is preferably a structural unit derived from a compound having a structure represented by the following general formula (A).

Formula (A)
HOOC- (CR ¹ = CR ² ) n-COOH

In general formula (A), R ¹ and R ² each independently represents a hydrogen atom, a methyl group or an ethyl group. n represents 1 or 2.

  By including the structural unit derived from such unsaturated aliphatic dicarboxylic acid, the hydrophilicity of the polyester resin increases due to the presence of the carbon-carbon double bond, so that the toner is obtained by the emulsion aggregation method in an aqueous medium. When the particles are produced, the effect of the polyester resin segment being oriented outward, that is, toward the aqueous medium side with respect to the toner base particle precursor is increased, and a convex portion is easily formed on the surface of the toner base particle precursor. Moreover, in this invention, when using unsaturated aliphatic dicarboxylic acid which has a structure represented by general formula (A) for a polymerization reaction, it can also be used with the form of an anhydride.

  Further, the content of the hybrid amorphous polyester resin in the toner base particles is in the range of 5 to 20% by mass in the total resin amount, and the effect as a convex portion is obtained without hindering the fixing property. It is preferable in that it can be obtained.

(1) Glass transition point and softening point From the viewpoint of low-temperature fixability, the hybrid amorphous polyester resin preferably has a glass transition point in the range of 50 to 70 ° C, more preferably in the range of 50 to 65 ° C. It is preferable that the softening point is in the range of 80 to 110 ° C.

  The glass transition point of the hybrid amorphous polyester resin is a value measured by a method (DSC method) defined in ASTM (American Society for Testing of Materials) D3418-12el, and the above-mentioned toner base particle precursor resin and It can be measured by the same measurement method.

  In addition, the softening point of the hybrid amorphous polyester resin can be measured by the same measurement method as that for the toner base particle precursor resin described above.

(2) Production Method of Hybrid Amorphous Polyester Resin As a method for producing a hybrid amorphous polyester resin, an existing general scheme can be used. The following four methods are listed as typical methods.

  (A) A polyester-based polymer segment is polymerized in advance, the polyester-based polymer segment is allowed to react with both reactive monomers, and an aromatic vinyl monomer for forming a vinyl-based polymer segment and ( A method of forming a vinyl polymerized segment by reacting a (meth) acrylic acid ester monomer. That is, an aromatic vinyl monomer and a (meth) acrylic acid ester monomer for forming a vinyl polymer segment, a polyvalent carboxylic acid monomer or a polyvalent monomer for forming a polyester polymer segment, A method of polymerizing in the presence of an amphoteric monomer having a group capable of reacting with an alcohol monomer and a polymerizable unsaturated group, and an unmodified polyester resin.

  (B) A vinyl-based polymer segment is polymerized in advance, the vinyl-based polymer segment is reacted with an amphoteric monomer, and a polyvalent carboxylic acid monomer and a polymer for forming a polyester-based polymer segment are further formed. A method of forming a polyester-based polymer segment by reacting a monohydric alcohol monomer.

  (C) A method in which a polyester-based polymer segment and a vinyl-based polymer segment are respectively polymerized in advance, and then both reactive monomers are reacted with each other to bond them together.

  (D) A polyester polymer segment is polymerized in advance, and a vinyl polymerizable monomer is added to the polymerizable unsaturated group of the polyester polymer segment or reacted with a vinyl group in the vinyl polymer segment to bond them together. how to.

  Here, the bireactive monomer means a group capable of reacting with a polyvalent carboxylic acid monomer or a polyhydric alcohol monomer for forming a polyester-based polymerization segment of a hybrid amorphous polyester resin, and a polymerization. It is a monomer having a polymerizable unsaturated group.

The method (A) will be specifically described.
(I) Mixing of an unmodified polyester resin for forming a polyester polymerized segment, an aromatic vinyl monomer and a (meth) acrylic acid ester monomer, and a bireactive monomer Process,
(Ii) A polyester system is obtained by polymerizing an aromatic vinyl monomer and a (meth) acrylate monomer in the presence of both reactive monomers and an unmodified polyester resin. A vinyl polymer segment can be formed at the terminal of the polymer segment. In this case, the terminal hydroxyl group of the polyester polymer segment and the carboxy group of the both reactive monomers form an ester bond, and the vinyl group of the both reactive monomers is an aromatic vinyl monomer or (meta ) A vinyl polymer segment is bonded by bonding to a vinyl group of an acrylic acid monomer. Of the above synthesis methods, the method (A) is most preferred.

  In the mixing step (I), it is preferable to heat. The heating temperature may be in a range where an unmodified polyester resin, aromatic vinyl monomer, (meth) acrylic acid ester monomer and both reactive monomers can be mixed, and is good. Since mixing is obtained and polymerization control becomes easy, it can be, for example, in the range of 80 to 120 ° C, more preferably in the range of 85 to 115 ° C, and still more preferably in the range of 90 to 110 ° C. It is.

  The relative proportion of the aromatic vinyl monomer and the (meth) acrylate monomer is such that the glass transition point (Tg) calculated by the FOX formula represented by the following formula (1) is 35. It is preferable that the ratio is in the range of -80 ° C, preferably in the range of 40-60 ° C.

Formula (1): 1 / Tg = Σ (Wx / Tgx)
(Wx is the mass fraction of monomer x. Tgx is the glass transition point of the homopolymer of monomer x.)

  In the present invention, the bireactive monomer is not used for calculation of the glass transition point.

(2.1) Amount of both reactive monomers added Among unmodified polyester resin, aromatic vinyl monomer, (meth) acrylic acid ester monomer, and both reactive monomers, both reactions The proportion of the reactive monomer used is the total mass of the resin material used, that is, the ratio of both reactive monomers when the total mass of the above four components is 100 mass% is 0.1 to 5.0 mass. %, And more preferably in the range of 0.5 to 3.0% by mass.

(2.2) Amphoteric monomer As the amphoteric monomer for forming the vinyl polymer segment, a polyvalent carboxylic acid monomer or a polyhydric alcohol monomer for forming the polyester polymer segment is used. A monomer having a group capable of reacting with a monomer and a polymerizable unsaturated group may be used. Specifically, acrylic acid, methacrylic acid, fumaric acid, maleic acid, maleic anhydride, and the like can be used. . In the present invention, it is preferable to use acrylic acid or methacrylic acid as the bireactive monomer.

(2.3) Vinyl Polymerization Segment The aromatic vinyl monomer and (meth) acrylic acid ester monomer for forming the vinyl polymerization segment are ethylenically unsaturated bonds capable of radical polymerization. It is what has.

(2.4) Aromatic vinyl monomers and (meth) acrylic acid ester monomers As aromatic vinyl monomers, for example, styrene, o-methylstyrene, m-methylstyrene, p-methyl Styrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, p-ethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, Examples thereof include pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, 2,4-dimethyl styrene, 3,4-dichlorostyrene, and the like.
These aromatic vinyl monomers can be used singly or in combination of two or more.

Examples of (meth) acrylic acid ester monomers include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, and methacrylic acid. Examples include butyl, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, propyl γ-aminoacrylate, stearyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and the like.
These (meth) acrylic acid ester monomers can be used alone or in combination of two or more.

  As the aromatic vinyl monomer and (meth) acrylic acid ester monomer for forming the vinyl polymer segment, many styrene or its derivatives are used from the viewpoint of obtaining excellent chargeability and image quality characteristics. It is preferable to use it. Specifically, the amount of styrene or its derivative used is the total amount of monomers (aromatic vinyl monomer and (meth) acrylic acid ester based monomer) used to form the styrene / acrylic polymer segment. It is preferable that it is 50 mass% or more in the body.

(2.5) Polymerization initiator In the polymerization step of polymerizing the above-mentioned aromatic vinyl monomer and (meth) acrylic acid ester monomer, the polymerization is preferably performed in the presence of a radical polymerization initiator. The timing of adding the radical polymerization initiator is not particularly limited, but it is preferably added after the mixing step in terms of easy control of radical polymerization.

Various known polymerization initiators are preferably used as the polymerization initiator. Specifically, hydrogen peroxide, acetyl peroxide, cumyl peroxide, tert-butyl peroxide, propionyl peroxide, benzoyl peroxide, chlorobenzoyl peroxide, dichlorobenzoyl peroxide, bromomethylbenzoyl peroxide, peroxide Lauroyl, ammonium persulfate, sodium persulfate, potassium persulfate, diisopropyl peroxycarbonate, tetralin hydroperoxide, 1-phenyl-2-methylpropyl-1-hydroperoxide, pertriphenylacetic acid-tert-hydroperoxide, performic acid-tert- Such as butyl, tert-butyl peracetate, tert-butyl perbenzoate, tert-butyl perphenylacetate, tert-butyl permethoxyacetate, tert-butyl perN- (3-toluyl) palmitate Oxides, 2,2 ' Azobis (2-aminodipropane) hydrochloride, 2,2'-azobis- (2-aminodipropane) nitrate, 1,1'-azobis (1-methylbutyronitrile-3-sodium sulfonate), 4, Examples thereof include azo compounds such as 4'-azobis-4-cyanovaleric acid and poly (tetraethylene glycol-2,2'-azobisisobutyrate).
The addition amount of the polymerization initiator varies depending on the desired molecular weight and molecular weight distribution, but specifically, it is preferably added in the range of 0.1 to 5.0% by mass with respect to the polymerizable monomer.

(2.6) Chain transfer agent In the polymerization step of polymerizing the aromatic vinyl monomer and the (meth) acrylic acid ester monomer, adjusting the molecular weight of the styrene / acrylic polymer segment. For the purpose, a commonly used chain transfer agent can be used. The chain transfer agent is not particularly limited, and examples thereof include alkyl mercaptans and mercapto fatty acid esters.

  The chain transfer agent is preferably mixed with the resin forming material in the mixing step.

  The addition amount of the chain transfer agent varies depending on the molecular weight and molecular weight distribution of the desired styrene / acrylic polymer segment. Specifically, the aromatic vinyl monomer and the (meth) acrylate monomer and both It is preferable to add in the range of 0.1 to 5.0 mass% with respect to the total amount of reactive monomers.

  The polymerization temperature in the polymerization step for polymerizing the aromatic vinyl monomer and the (meth) acrylic acid ester monomer is not particularly limited, and the aromatic vinyl monomer and the (meth) acrylic acid ester type are not limited. It can select suitably in the range in which the superposition | polymerization between monomers and the coupling | bonding to a polyester resin advance. For example, the polymerization temperature is preferably in the range of 85 to 125 ° C, more preferably in the range of 90 to 120 ° C, and still more preferably in the range of 95 to 115 ° C.

(2.7) Polyester-based polymer segment Resin used to produce the polyester-based polymer segment constituting the hybrid amorphous polyester resin is a polyvalent carboxylic acid monomer (derivative) and a polyhydric alcohol monomer (derivative). ) Is preferably produced by a polycondensation reaction in the presence of an appropriate catalyst.

  As the polyvalent carboxylic acid monomer, alkyl esters, acid anhydrides and acid chlorides of the polyvalent carboxylic acid monomer can be used. As the polyhydric alcohol monomer, the polyhydric alcohol monomer can be used. Esters and hydroxycarboxylic acids can be used.

  Examples of the polycarboxylic acid monomer include oxalic acid, succinic acid, maleic acid, adipic acid, β-methyladipic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, undecanedicarboxylic acid, and dodecanedicarboxylic acid. , Fumaric acid, citraconic acid, diglycolic acid, cyclohexane-3,5-diene-1,2-dicarboxylic acid, malic acid, citric acid, hexahydroterephthalic acid, malonic acid, pimelic acid, tartaric acid, mucic acid, phthalate Acid, isophthalic acid, terephthalic acid, tetrachlorophthalic acid, chlorophthalic acid, nitrophthalic acid, p-carboxyphenylacetic acid, p-phenylenediacetic acid, m-phenylenediglycolic acid, p-phenylenediglycolic acid, o-phenylenediglycol Acid, diphenylacetic acid, diphenyl-p, p'-di Divalent carboxylic acids such as rubonic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, anthracene dicarboxylic acid, dodecenyl succinic acid, trimellitic acid, pyromellitic Examples thereof include trivalent or higher carboxylic acids such as acid, naphthalenetricarboxylic acid, naphthalenetetracarboxylic acid, pyrenetricarboxylic acid, and pyrenetetracarboxylic acid.

  As the polyvalent carboxylic acid monomer, it is preferable to use an unsaturated aliphatic dicarboxylic acid such as fumaric acid, maleic acid or mesaconic acid, and in particular, an unsaturated fat having a structure represented by the general formula (A). It is preferable to use a group dicarboxylic acid. In the present invention, an anhydride of a dicarboxylic acid such as maleic anhydride can also be used.

  Examples of the polyhydric alcohol monomer include ethylene glycol, propylene glycol, butanediol, diethylene glycol, hexanediol, cyclohexanediol, octanediol, decanediol, dodecanediol, ethylene oxide adduct of bisphenol A, and propylene oxide addition of bisphenol A. And dihydric alcohols such as glycerin, pentaerythritol, hexamethylol melamine, hexaethylol melamine, tetramethylol benzoguanamine, tetraethylol benzoguanamine and the like.

In order to form the polyester-based polymer segment constituting the hybrid amorphous polyester resin, it is preferable to use a monomer that does not contain a linear alkyl group as the polyvalent carboxylic acid and polyhydric alcohol.
The polyhydric alcohol monomer contains a structural unit of an ethylene oxide adduct of bisphenol A and a propylene oxide adduct of bisphenol A.
By containing the structural unit of bisphenol A ethylene oxide adduct and bisphenol A propylene oxide adduct, compatibility with the crystalline polyester resin can be controlled, and the crystalline polyester resin is exposed on the surface of the toner base particle precursor. That can be suppressed.

  The ratio of the polyhydric carboxylic acid monomer to the polyhydric alcohol monomer is the equivalent ratio [OH] of the hydroxy group [OH] of the polyhydric alcohol monomer to the carboxy group [COOH] of the polyhydric carboxylic acid. / [COOH] is preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2.

  As the catalyst for synthesizing the polyester resin, various conventionally known catalysts can be used.

  The amorphous polyester resin for obtaining the hybrid amorphous polyester resin preferably has a glass transition point in the range of 40 to 70 ° C, more preferably in the range of 50 to 65 ° C. When the glass transition point of the amorphous polyester resin is 40 ° C. or higher, the cohesive force in the high temperature region becomes appropriate for the amorphous polyester resin, and the occurrence of hot offset phenomenon during the fixing is suppressed. . Further, when the glass transition point of the amorphous polyester resin is 70 ° C. or less, sufficient melting can be obtained at the time of fixing, and a sufficient minimum fixing temperature can be ensured.

Moreover, it is preferable that the weight average molecular weight (Mw) of the said amorphous polyester resin exists in the range of 1500-60000, More preferably, it exists in the range of 3000-40000.
When the weight average molecular weight is 1500 or more, a cohesive force suitable for the entire toner base particle precursor resin is obtained, and the occurrence of a high temperature offset phenomenon during fixing is suppressed. Further, when the weight average molecular weight is 60000 or less, a sufficient melt viscosity can be obtained and a sufficient minimum fixing temperature can be ensured, so that the occurrence of a low temperature offset phenomenon during fixing is suppressed.

  The amorphous polyester resin has a partially branched structure or a crosslinked structure formed by selecting a carboxylic acid valence or an alcohol valence as a polyvalent carboxylic acid monomer or a polyhydric alcohol monomer to be used. May be.

  In the production of the hybrid amorphous polyester resin, it is practically preferable that the volatile organic substances from the emulsion such as the residual monomer amount after the polymerization step are suppressed to 1000 ppm or less, more preferably 500 ppm or less, Preferably it is 200 ppm or less.

(3) Average long side length of convex part It is preferable that the average long side length of the convex part which concerns on this invention exists in the range of 100-300 nm. If the average long side length of the surface convex portions is 100 nm or more, the convex portions enter the surface concave portions, and the closeness between the toner particles is improved without forming a gap. In addition, when the average long side length is 300 nm or less, the convexity does not enter the surface concave portion, and the closeness is improved.
The long side length of the convex portion is the convexity in the SEM image data when 10000 times observation is performed with a scanning electrophotographic microscope (hereinafter referred to as SEM) “JSM-7401F” (manufactured by JEOL Ltd.). The part where the distance between the two parallel lines is the maximum (long side) when the part and the non-convex part are visually confirmed, the contour line is drawn for each convex part, and the contour line is sandwiched between the two parallel lines. Length X) (see FIG. 4). In the measurement, the long side length of 20 convex portions having a long side length of 30 nm or more is measured. The same measurement is performed on five toner base particles, and the average value thereof is set as the average long side length of the convex portion according to the present invention.

(4) Average interval of convex part It is preferable that the average interval of the convex part which concerns on this invention exists in the range of 20-200 nm. If the average interval of the surface convex portions is 20 nm or more, the convex portions enter the concave portions, and the closeness is improved. Further, when the average interval is 200 nm or less, the closeness between the toner particles is improved without forming a gap even if the convex portion enters the concave portion.
As for the interval between the convex portions, in the SEM image data of 10,000 times observation, four convex portions are picked up in order from the convex portion around each convex portion and picked up from the outer periphery of the central convex portion. The average of the shortest distances (Y1 to Y4) to the outer periphery of the convex part is defined as the convex part interval (see FIG. 4). In the measurement, the interval between the protrusions measured around the protrusions having a long side length of 30 nm or more is measured for 20 protrusions. The same measurement is performed on the five toner base particles, and the average value thereof is set as the average interval of the convex portions according to the present invention (see FIG. 4). The long side length of the four convex portions to be picked up is not limited.

As control means for the average long side length and average interval of the convex portions, (a) resin configuration, (b) particle size of convex portion resin, (c) amount of convex portion resin added, (iv) convex portion The average circularity of the toner base particle precursor before the resin for charging is added, and (e) the fusion time of the convex resin (average circularity of the toner base particles).
(A) Regarding the particle size of the resin for the convex portion, the larger the particle size, the longer the length of the convex portion and the wider the interval between the convex portions. Specifically, the particle diameter of the convex resin particles is preferably in the range of 50 to 300 nm.
(C) Regarding the amount of the resin for the convex portion, as the amount of the resin for the convex portion increases, the length of the convex portion becomes longer and the interval between the convex portions becomes narrower. Specifically, the content of the convex portion resin is preferably in the range of 5 to 20% by mass in the total resin amount of the toner base particles.
(D) Regarding the average circularity of the toner base particle precursor before the resin for the convex portion is added, the convex portion can be easily formed by increasing the average circularity. Specifically, the average circularity of the toner base particle precursor is preferably 0.890 or more.
(E) Regarding the fusion time of the convex resin, the longer the fusion time, the more the difference between the average circularity of the toner base particles and the average circularity of the toner base particle precursor before the convex resin is charged. It becomes larger and the length of the convex part becomes shorter. Specifically, the fusion time of the convex resin is preferably in the range of 10 to 180 minutes, and more preferably in the range of 30 to 120 minutes.

(5) Average height of the convex portion The average height of the convex portion is within the range of 40 to 120 nm so that the heat resistance can be secured, the effect of the external additive is hardly hindered, and the charging property is stable. This is preferable.
The average height of the protrusions was picked up from the toner base particle precursor surface by picking up 20 protrusions having a long side length of 30 nm or more for 10 toner base particles in the SEM image data observed at 10000 times magnification. The vertex of the portion is sandwiched between two parallel lines, the portion where the distance between the two parallel lines is the maximum is the height of the convex portion, and the average value is the average height of the convex portion.

(6) Average distribution density of protrusions The average distribution density of protrusions on the surface of the toner base particle precursor is in the range of 8 to 25 particles / μm ² , and both heat resistance and fixing belt separation can be achieved. Is preferable.
The average distribution density of the convex portions was measured by measuring the number of convex portions having a long side length of 30 nm or more per 1 μm ² with respect to 10 toner base particles in SEM image data observed at a magnification of 10,000 times. The average distribution density of parts.
In addition, about the number of convex parts, what exists on a boundary line shall not be counted.

(7) Method for forming convex portions As a method for forming convex portions on the surface of the toner base particle precursor according to the present invention, for example, the convex portion and the toner base particle precursor have different resin compositions, and the monomers of both resins are used. Although it can be adjusted by the composition, it is not limited to this as long as it is a method capable of forming a convex portion.
For example, when the main binder resin of the toner base particle precursor is a vinyl resin, an amorphous polyester resin is used for the convex portion. In particular, when an amorphous polyester resin containing a structural unit of bisphenol A propylene oxide adduct and bisphenol A ethylene oxide adduct is used, the toner can be controlled so as not to be compatible with the crystalline polyester resin. Protrusions can be effectively formed on the surface of the base particle precursor.

<External additive>
The electrostatic image developing toner of the present invention is characterized by containing alumina particles as an external additive. The external additive may contain conventionally known external additives in addition to the alumina particles.

  The content of all external additives contained in the toner particles is not particularly limited, but for example, within the range of 0.1 to 10.0 parts by mass with respect to 100 parts by mass of the toner base particles. It is preferable that it is in the range of 1.0 to 3.0 parts by mass.

(Alumina particles)
Alumina refers to aluminum oxide represented by Al ₂ O ₃ , and forms such as α-type, γ-type, σ-type, and mixtures thereof are known, and the shape is cubic by controlling the crystal system. There are a variety of things from spherical to spherical.

  The number average particle diameter of the alumina particles is preferably in the range of 5 to 60 nm, and more preferably in the range of 5 to 40 nm. When the number average particle diameter of the alumina particles is 5 nm or more, the alumina particles can be produced more easily. When the thickness is 60 nm or less, the fluidity of the toner is improved, and when the toner is supplied to the developing device, the toner and the carrier are sufficiently mixed, and a more stable charge amount transition is obtained.

The number average particle diameter of the alumina particles can be measured as follows.
Using a scanning electron microscope (SEM) “JSM-7401F” (manufactured by JEOL Ltd.), an SEM photograph magnified 50,000 times is captured by a scanner. With the image processing analysis device “LUZEX AP” (manufactured by Nireco), the alumina particles of the SEM photograph image are binarized, the horizontal ferret diameter for 100 alumina particles is calculated, and the average value is the number Average particle diameter.

  The content of alumina particles in the toner particles is preferably in the range of 0.1 to 2.0 parts by mass with respect to 100 parts by mass of the toner base particles. When the content of the alumina particles is 0.1 parts by mass or more, the number of alumina particles adhering to the toner base particles is large, so that the effect of improving sticking can be improved. When the amount is 2.0 parts by mass or less, the probability that the alumina particles are subjected to impact of the toner particles and carrier particles when the developer is stirred in the developing device during low coverage printing can be suppressed. It is possible to make it less likely to be buried in the toner base particles.

  The amount of alumina particles attached to the toner base particles after the ultrasonic vibration treatment of the toner of the present invention is 60 to 100% of the amount of alumina particles attached to the toner base particles before the ultrasonic vibration treatment. Is preferably in the range of 60 to 80%. As a result, the amount of transfer of the external additive from the toner base particles to the carrier can be reduced, and fluctuations in the charge amount can be more effectively suppressed.

The amount of alumina particles adhering to the toner base particles before the ultrasonic vibration treatment can be determined by performing fluorescent X-ray analysis on the toner and measuring the amount of alumina.
Further, the amount of the alumina particles attached to the toner base particles after the ultrasonic vibration treatment can be determined as follows. First, 3 g of toner is sufficiently dispersed in 35 mL of a 0.2% by mass polyoxyethylene octylphenyl ether aqueous solution. Then, using a circulating ultrasonic homogenizer (Ultrasonic Homogenizer US-1200T manufactured by Nippon Seiki Seisakusho), the dispersion is irradiated with ultrasonic waves for 2 minutes under the conditions of 20 kHz and 40 to 60 μA with a φ36 chip. As a result, the external additive is separated from the surface of the toner base particles, and then the dispersion is centrifuged to separate the precipitate and the supernatant. After washing and drying the precipitate, the dried material is subjected to fluorescent X-ray analysis, and the amount of remaining alumina is measured.
From the values obtained before and after the ultrasonic vibration treatment, the ratio (%) of the adhesion amount after treatment to the adhesion amount before treatment can be obtained.

  The surface of the alumina particles is preferably subjected to a hydrophobic treatment with a surface treatment agent, and the degree of hydrophobicity is preferably in the range of 40 to 70, for example. As a result, fluctuations in the charge amount due to environmental differences and fluctuations in the charge amount when shifting to the carrier can be more effectively suppressed. Moreover, it is preferable that the liberation rate of the surface treatment agent at the time of the hydrophobic treatment is 0. If there is a free surface treating agent, it moves to the carrier, and the charge amount fluctuation becomes large.

The degree of hydrophobicity of the alumina particles can be determined by measuring as follows.
Under a laboratory environment, a 20-mm long stirrer chip and 60 mL of 25 ° C. ion-exchanged water are placed in a 200 mL tall beaker, and set in a powder wettability tester (WET-101P: Reska Co., Ltd.). Float 50 mg of alumina particles on ion-exchanged water, immediately set a lid and a methanol supply nozzle, and start measurement simultaneously with the start of stirrer stirring. The supply rate of methanol (special grade, manufactured by Kanto Chemical Co., Ltd.) is 2.0 mL / min, the measurement time is 70 minutes, and the stirring speed of the stirrer is 380 to 420 rpm. The alumina particles are initially floating at the interface of the ion exchange water, but gradually get wet with the mixed solution of the ion exchange water and methanol and disperse in the liquid as the methanol concentration increases. Thereby, the light transmittance of the liquid gradually decreases. From the obtained data, the horizontal axis shows the methanol concentration (vol%) calculated from the methanol supply (mL), and the vertical axis shows the light transmittance (voltage ratio) (%). The light transmittance is the maximum value. And the minimum methanol concentration can be determined as the degree of hydrophobicity.

  As the surface treatment agent, for example, a common coupling agent, silicone oil, fatty acid, fatty acid metal salt, or the like can be used, but it is preferable to use a silane compound, silicone oil, or the like.

  Examples of the silane compound include chlorosilane, alkoxysilane, silazane, and a special silylating agent. Specifically, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, octyltrimethoxysilane , Tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltrimethoxysilane, decyltrimethoxysilane, hexamethyldisilazane, N, O- (bistrimethylsilyl) acetamide, N, N-bis (trimethylsilyl) urea, tert-butyldimethylchlorosilane, vinyltrichlorosilane, vinyltrimeth Sisilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxy Examples include silane, γ-mercaptopropyltrimethoxysilane, and γ-chloropropyltrimethoxysilane. Particularly preferred are isobutyltrimethoxysilane and octyltrimethoxysilane.

  Examples of the silicone oil include cyclic compounds such as organosiloxane oligomers, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, tetramethylcyclotetrasiloxane, tetravinyltetramethylcyclotetrasiloxane, and linear or branched organo Mention may be made of siloxane. Further, a highly reactive silicone oil in which a modifying group is introduced into a side chain, one end or both ends, a side chain piece end, or both side chain ends may be used. Examples of the modifying group include, but are not particularly limited to, alkoxy, carboxy, carbinol, higher fatty acid modification, phenol, epoxy, methacryl, amino and the like. Further, for example, a silicone oil having several kinds of modifying groups such as an amino group and an alkoxy group may be used. Moreover, it may mix with another surface treatment agent and may perform a hydrophobic treatment, and both the hydrophobic treatment by a silicone oil and the hydrophobic treatment by another surface treatment agent may be performed. Examples of other surface treatment agents in this case include silane coupling agents, titanate coupling agents, aluminate coupling agents, various silicone oils, fatty acids, fatty acid metal salts, esterified products thereof, rosin acid and the like. can do.

  As a method of hydrophobizing alumina particles with a surface treatment agent, for example, a dry method such as a spray drying method in which a surface treatment agent or a solution containing the surface treatment agent is sprayed on alumina particles suspended in a gas phase, Examples include a wet method in which alumina particles are immersed in a solution containing a surface treatment agent and drying, and a mixing method in which the surface treatment agent and alumina particles are mixed with a mixer.

Alumina can be produced by a known method. As a method for producing alumina, the Bayer method is generally used, but in order to obtain high-purity and nano-sized alumina, hydrolysis method, gas phase synthesis method, flame hydrolysis method, underwater spark discharge method, etc. are mentioned. It is done.
For example, it can be produced by adapting to the known burner device described in Example 1 of European Patent No. 0585544 with reference to the content described in JP2012-224542A.
For example, aluminum trichloride (AlCl ₃ ) 320 kg / h is evaporated in an evaporator at about 200 ° C. and chloride vapor is passed through the mixing chamber of the burner with nitrogen. Here, to supply a flow of gas is mixed with hydrogen 100 Nm ³ / h and air 450 Nm ³ / h, via the central tube (diameter 7 mm) to the flame. The burner temperature is 300 ° C., and the discharge speed of the tube is about 39.8 m / s. Hydrogen 0.05 Nm ³ / h is supplied through the outer tube as a jacket type gas. The gas burns in the reaction chamber and is cooled to about 110 ° C. in the downstream agglomeration zone. There, the primary particles of alumina are agglomerated.
From the hydrochloric acid-containing gas produced at the same time, the alumina particles are separated in a filter or cyclone, and the powder with wet air is treated at about 500-700 ° C. to remove the adhesive chloride.
As described above, alumina particles can be obtained.
The shape and particle size of the alumina particles can be changed according to reaction conditions such as flame temperature, hydrogen or oxygen content, aluminum trichloride quality, residence time in the flame or length of the agglomeration zone.

(Other external additives)
The external additive according to the present invention preferably contains other external additives in addition to the alumina particles from the viewpoint of controlling the fluidity and chargeability of the toner particles. Examples of such external additives include silica particles, titania particles, zirconia particles, zinc oxide particles, chromium oxide particles, cerium oxide particles, antimony oxide particles, tungsten oxide particles, tin oxide particles, tellurium oxide particles, manganese oxide. Examples thereof include particles and boron oxide particles.

  The number average particle diameter of the other external additives can be adjusted, for example, by classification or mixing of classified products. The number average particle size of other external additives can be measured by the same method as the method for measuring the number average particle size of the alumina particles described above.

  The surface of other external additives is preferably hydrophobized from the viewpoint of improving heat-resistant storage stability and environmental stability. A known surface modifier is used for the hydrophobic treatment. Examples of the surface modifier include silane coupling agents, titanate coupling agents, aluminate coupling agents, fatty acids, fatty acid metal salts, esterified products thereof, rosin acid, and silicone oil.

  As other external additives, silica particles are preferably used from the viewpoint of imparting chargeability, and silica particles having a primary particle number average particle size in the range of 10 to 60 nm are more preferably used. As a result, the toner fluidity is improved, and when the toner is supplied to the developing device, the toner particles and the carrier particles can be sufficiently mixed, so that a stable charge amount transition can be obtained. Furthermore, it is preferable to use together silica particles having a number average particle size of primary particles of 80 to 150 nm together with silica particles having a number average particle size of 10 to 60 nm. Thereby, the impact of the toner particles and the carrier particles when the developer is stirred in the developing device at the time of low coverage printing can be reduced.

  Organic particles can also be used as other external additives. As the organic particles, spherical organic particles having a number average particle diameter of about 10 to 2000 nm can be used. Specifically, homopolymers such as styrene and methyl methacrylate and organic particles of these copolymers can be used. A lubricant can also be used as another external additive. The lubricant is used for the purpose of further improving the cleaning property and the transfer property, and specifically includes zinc stearate, a salt of aluminum, copper, magnesium, calcium, zinc oleate, manganese. Metal salts of higher fatty acids such as salts of iron, copper, magnesium, etc., zinc of palmitic acid, salts of copper, magnesium, calcium, etc., zinc of linoleic acid, salts of calcium, etc., zinc of ricinoleic acid, salts of calcium, etc. Is mentioned.

<Softening point of toner>
The softening point of the toner for developing an electrostatic charge image of the present invention is preferably in the range of 85 to 130 ° C, and more preferably in the range of 90 to 115 ° C. When the softening point of the toner is within this range, preferable low-temperature fixability can be obtained. If the softening point of the toner is 130 ° C. or lower, the toner particles are more likely to be crushed during fixing, and this is suitable for creating a state where there is no void in the image (toner layer). If it is 85 degreeC or more, heat resistance will improve and it is practical.
The softening point can be measured by the above-described method, that is, the flow tester “CFT-500D” (manufactured by Shimadzu Corporation).

<Average circularity of toner particles>
The average circularity of the toner particles is preferably in the range of 0.940 to 0.980.
Here, the average circularity of the toner particles is a value measured using a flow particle image analyzer “FPIA-2100” (manufactured by Sysmex).
Specifically, the toner particles are moistened with an aqueous surfactant solution, and ultrasonic dispersion is performed for 1 minute. After dispersion, HPFP detection is performed in the measurement condition HPF (high magnification imaging) mode using “FPIA-2100”. Measurement is performed at an appropriate concentration within a range of several thousand to 10,000. Within this range, reproducible measurement values can be obtained. The circularity is calculated by the following formula.

  Circularity = (perimeter of a circle having the same projection area as the particle image) / (perimeter of the particle projection image)

  The average circularity is an arithmetic average value obtained by adding the circularity of each particle and dividing by the total number of particles measured.

<Toner particle size>
The toner particles preferably have a volume-based median diameter (D ₅₀ ) in the range of 3 to 10 μm.
By setting the volume-based median diameter (D ₅₀ ) within the above range, it is possible to faithfully reproduce, for example, a very small dot image of 1200 dpi (dpi: number of dots per inch: 2.54 cm) level. become.

The volume-based median diameter (D ₅₀ ) of the toner particles can be measured and calculated using, for example, a device in which a computer system for data processing is connected to “Multisizer 3 (manufactured by Beckman Coulter)”.
As a measurement procedure, 0.02 g of toner particles are added with 20 mL of a surfactant solution (for example, a surfactant solution obtained by diluting a neutral detergent containing a surfactant component 10 times with pure water for the purpose of dispersing toner particles). After being blended, ultrasonic dispersion is performed for 1 minute to prepare a toner particle dispersion. This toner particle dispersion is injected into a beaker containing ISOTON II (manufactured by Beckman Coulter) in a sample stand with a pipette until the measured concentration falls within a range of 5 to 10% by mass, and 25000 measuring machine counts are obtained. Set to and measure. The aperture size of the multisizer 3 is 100 μm. The frequency number obtained by dividing the measurement range of 1 to 30 μm into 256 parts is calculated, and the particle diameter of 50% from the larger volume integrated fraction is defined as the volume reference median diameter (D ₅₀ ).

<< Method for producing toner for developing electrostatic image >>
Examples of the method for producing the toner base particles according to the present invention include a suspension polymerization method, an emulsion aggregation method, and other known methods. The emulsion aggregation method is preferably used. According to this emulsion aggregation method, the toner particles can be easily reduced in size from the viewpoint of production cost and production stability.

  Here, the emulsion aggregation method refers to a dispersion of resin particles for toner base particle precursor produced by emulsification (specifically, a dispersion of amorphous resin particles and a dispersion of crystalline polyester resin particles). If necessary, the liquid is mixed with a dispersion of colorant particles (hereinafter also referred to as “colorant particles”), aggregated to a desired toner particle size, and further fused between the resin particles. This is a method for producing toner base particles by performing shape control. Here, the resin particles for the toner base particle precursor may optionally contain a release agent, a charge control agent and the like.

Specific examples of production when the toner base particles according to the present invention are produced by an emulsion aggregation method are as follows:
Step (1): A step of preparing a dispersion of resin particles comprising a resin for toner base particle precursor,
Step (2): A step of preparing a dispersion of resin particles made of a convex resin,
Step (3): a step of forming a toner base particle precursor by aggregating resin particles contained in a dispersion of resin particles for toner base particle precursor;
Step (4): A step of forming toner base particles by fusing the resin particles for convex portions to a toner base particle precursor in an aqueous medium.
Through this, toner base particles are formed.

  In the step (1), the toner base particle precursor resin particles may have a multilayer structure of two or more layers made of resins having different compositions. For the resin particles having such a structure, for example, those having a two-layer structure are prepared by preparing a dispersion of resin particles by emulsion polymerization treatment (first stage polymerization) according to a conventional method, and adding a polymerization initiator to the dispersion. It can be obtained by adding a polymerizable monomer and polymerizing this system (second stage polymerization). Moreover, if necessary, a polymerizable monomer may be further added to carry out the third stage polymerization to form a three-layer structure.

  After the step (4), the toner base particles are filtered from the aqueous medium to remove the surfactant and the like from the toner base particles, and the drying step of drying the cleaned toner base particles; Further, if necessary, toner particles can be produced through an external additive addition step of adding an external additive to the dried toner base particles.

  In the present invention, the “aqueous medium” refers to a medium comprising 50 to 100% by mass of water and 0 to 50% by mass of a water-soluble organic solvent. Examples of the water-soluble organic solvent include methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran, and alcohol-based organic solvents that do not dissolve the resulting resin are preferable.

(Step (1): Step of preparing a dispersion of resin particles for toner base particle precursor)
In step (1), a dispersion of toner base particle precursor resin particles containing a toner base particle precursor resin and a wax is prepared.
A dispersion of resin particles for a toner base particle precursor can be prepared by emulsion polymerization in an aqueous medium.
The particle diameter of the resin particles in the dispersion of the resin particles for the toner base particle precursor is such that the volume-based median diameter (D ₅₀ ) is in the range of ₅₀ to 500 nm, and the average long side length of the protrusions and This is preferable in that the average interval can be controlled within the above-described range.

When using a surfactant in the polymerization process of the toner base particle precursor resin, for example, the above-described surfactants can be used as the surfactant.
Surfactant can be used individually by 1 type or in combination of 2 or more type as needed.

  The toner base particles according to the present invention may contain an internal additive such as a colorant, a charge control agent, or a magnetic powder, if necessary. Such an internal additive is, for example, the toner. In the polymerization step of the base particle precursor resin, it can be introduced into the toner base particles by dissolving or dispersing in advance in a monomer solution for forming the toner base particle precursor resin.

  In addition, such an internal additive is prepared by separately preparing a dispersion of internal additive particles consisting only of the internal additive, and in step (3), the internal additive together with the toner base particle precursor resin particles and the colorant particles. It is possible to introduce the toner particles into the toner base particles by aggregating the agent particles. However, it is preferable to adopt a method of introducing them in advance in the polymerization process of the toner base particle precursor resin.

The volume-based median diameter (D ₅₀ ) is measured using a microtrack particle size distribution measuring apparatus “UPA-150” (manufactured by Microtrack Bell).

(Step (2): Step of preparing a dispersion of convex portion resin particles)
In the step (2), a dispersion of resin particles made of the convex resin is prepared.
Specifically, as a method of preparing a dispersion of resin particles made of a resin for convex portions, for example, a method of pulverizing by a mechanical method and dispersing in an aqueous medium using a surfactant, dissolved in an organic solvent A method in which a resin solution for convex portions is charged and dispersed in an aqueous medium to obtain an aqueous medium dispersion, and a method in which the resin for convex portions is mixed with an aqueous medium in a molten state to obtain an aqueous medium dispersion by a mechanical dispersion method. In addition, any method may be used in the present invention.

The average particle diameter of the convexity resin particles obtained in step (2) is a volume-based median diameter _{(D 50),} for example, it is preferably in the range of 50 to 500 nm.

  When a surfactant is used in this step (2), the same surfactant as the surfactant that can be used, for example, in the above-described resin particle dispersion preparation step for toner base particle precursor is used. Things can be used.

(Colorant particle dispersion preparation process)
When the toner base particles contain a colorant, it is preferable to go through a step of preparing a colorant particle dispersion.
Specifically, the colorant particle dispersion can be prepared by dispersing the colorant in an aqueous medium. The colorant dispersion treatment is preferably performed in a state where the surfactant concentration in the aqueous medium is not less than the critical micelle concentration (CMC) since the colorant is uniformly dispersed. Various known dispersers can be used as a disperser used for the dispersion treatment of the colorant.

  As the surfactant to be used, for example, the same surfactants that can be used in the above-mentioned step of preparing the resin particle dispersion for toner base particle precursor can be used.

The dispersion diameter of the colorant particles in the colorant particle dispersion prepared in this colorant particle dispersion preparation step is preferably in the range of 10 to 300 nm in terms of volume-based median diameter (D ₅₀ ).

The volume-based median diameter (D ₅₀ ) of the colorant particles in the colorant particle dispersion is measured with an electrophoretic light scattering photometer “ELS-800 (manufactured by Otsuka Electronics Co., Ltd.)”.

(Step (3): Step of forming toner base particle precursor by agglomerating resin particles contained in dispersion of resin particles for toner base particle precursor)
In the step (3), the toner base particle precursor is formed by aggregating the resin particles contained in the dispersion liquid of the toner base particle precursor resin particles.
In this step (3), particles of other toner components such as a charge control agent and a colorant particle can be aggregated in the resin particles for the toner base particle precursor, if necessary.
In the step (1), the toner base particle precursor resin particles contain a release agent. In the step (1), the release agent is used as the toner base particle precursor resin particles. In the step (3), a particle dispersion containing only the release agent is prepared as a resin particle dispersion for a toner base particle precursor. You may mix.

  The specific method for forming the toner base particle precursor by aggregating the resin particles contained in the dispersion of the resin particles for the toner base particle precursor is not particularly limited, but the aggregating agent is critical in the aqueous medium. The toner base particle precursor is added by heating to a temperature above the glass transition point of the resin particles for toner base particle precursor and below the melting peak temperature of the mixture. And a method in which the salting out of the particles such as the resin particles and the colorant particles proceeds simultaneously and at the same time the fusion is advanced.

In this method, the time allowed to stand after adding the flocculant is shortened as much as possible, and the temperature is immediately above the glass transition point of the resin particles for the toner base particle precursor and below the melting peak temperature of these mixtures. It is preferable to heat it. The reason for this is not clear, but depending on the standing time after salting out, the aggregation state of the particles may fluctuate and the particle size distribution may become unstable, and the surface properties of the fused particles may vary. This is because there is concern about the occurrence.
The time until the start of the temperature increase is usually preferably within 30 minutes. Moreover, it is preferable that it is 1 degree-C / min or more as a temperature increase rate. The upper limit of the rate of temperature rise is not particularly specified, but is preferably 10 ° C./min or less from the viewpoint of suppressing the generation of coarse particles due to rapid progress of fusion. Furthermore, after the reaction system reaches a temperature equal to or higher than the glass transition point, it is important to continue the fusion by maintaining the temperature of the reaction system for a certain time. Thereby, the growth and fusion of the toner base particle precursor can be effectively advanced, and the durability of the finally obtained toner particles can be improved.
The toner base particle precursor is produced by aggregating and fusing crystalline polyester resin particles and amorphous resin particles in the presence of metal ions.
Here, the crystalline polyester resin can effectively exhibit low-temperature fixability by being finely dispersed in the toner. Further, as described above, it is preferable that the crystalline polyester resin does not exist on the surface of the toner base particle precursor and the surface of the toner base particle. Therefore, it is preferable to add the crystalline polyester resin before the toner base particle precursor grows before and after the addition of the flocculant or when the reaction system reaches a desired temperature.

(Flocculant)
The flocculant used in the step (3) is not particularly limited, but one selected from metal salts is preferably used. Examples of metal salts include monovalent metal salts such as alkali metal salts such as sodium, potassium and lithium, divalent metal salts such as calcium, magnesium, manganese and copper, and trivalent metal salts such as iron and aluminum. Etc. Specific metal salts can include sodium chloride, potassium chloride, lithium chloride, calcium chloride, magnesium chloride, zinc chloride, copper sulfate, magnesium sulfate, manganese sulfate, and the like. It is particularly preferable to use a divalent metal salt.
These can be used alone or in combination of two or more.

As for the particle size of the particles obtained in the step (3), for example, the volume-based median diameter (D ₅₀ ) is preferably in the range of 3 to 10 μm, more preferably in the range of 4 to 7 μm.
The volume-based median diameter (D ₅₀ ) of the particles is measured by “Coulter Multisizer 3” (manufactured by Beckman Coulter).

(Step (4): Step of forming toner base particles)
In step (4), the convex resin particles are fused to the toner base particle precursor in an aqueous medium to form toner base particles having a plurality of convex portions on the surface of the toner base particle precursor.
Specifically, in step (3), the toner base particle precursor is grown to a desired particle diameter, and a dispersion of resin particles for convex portions is added to the aqueous medium (reaction liquid) in step (3). The resin particles for convex portions are attached to the toner base particle precursor. Thereafter, the pH of the aqueous medium (reaction solution) is adjusted with a pH adjuster and fused.

As a specific method, first, an aggregating agent is added to the reaction solution so as to be equal to or higher than the critical aggregation concentration, and then the melting point temperature of the mixture is equal to or higher than the glass transition point of the convex resin particles. Heat to the following temperature.
Next, when the supernatant of the reaction solution (aqueous medium) becomes transparent, an aggregation stopper is added to stop particle growth. Furthermore, it heats up and heat-stirs in the state in the range of 80-90 degreeC.

Thereby, a plurality of convex portions can be formed on the surface of the toner base particle precursor, and toner base particles can be formed. Next, by cooling within a range of 20 to 30 ° C., a dispersion of toner base particles having convex portions on the surface of the toner base particle precursor is obtained.
In the step of forming the toner base particles, the fusing time for fusing the convex resin to the toner base particle precursor is preferably within a range of 10 to 180 minutes, and within a range of 30 to 120 minutes. However, it is more preferable at the point which can control the average long side length and average space | interval of a convex part in the above-mentioned range.

(Washing process, drying process)
The washing step and the drying step can be performed by employing various known methods. That is, the dispersion of the toner base particles is solid-liquid separated and washed by a known method such as a centrifugal separator, and the organic solvent is removed by drying under reduced pressure. Further, a flash jet dryer, a fluidized bed drying device, and the like. Water and a trace amount of organic solvent are removed by a known drying apparatus. The drying temperature may be in a range where the toner is not fused.

(External additive addition process)
The external additive adding step is a step of forming toner particles by adding and mixing the external additive to the dried toner base particles. In the present invention, at least alumina particles are contained as an external additive.

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

  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 base particles. Examples of the mixing device include mechanical mixing devices such as a Henschel mixer and a coffee mill. It is done.

<Developer>
The toner for developing an electrostatic charge image 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.

  As the carrier, magnetic particles made of conventionally known materials such as metals such as iron, ferrite and magnetite, and alloys of these metals with metals such as aluminum or lead can be used. Among these, ferrite particles are used. It is preferable to use it. As the carrier, a coated carrier in which the surface of magnetic particles is coated with a coating agent such as a resin, a resin-dispersed carrier in which a magnetic fine powder is dispersed in a binder resin, or the like may be used.

  The carrier preferably has a volume average particle size in the range of 15 to 100 μm, and more preferably in the range of 25 to 80 μm.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

<Preparation of amorphous resin dispersion>
Amorphous resin dispersions (SA1) and (SA2) were prepared as follows.

<Preparation of amorphous resin dispersion (SA1)>
(First stage polymerization)
Into a 5 L reaction vessel equipped with a stirrer, temperature sensor, cooling pipe and nitrogen introduction device, 8 parts by mass of sodium dodecyl sulfate and 3000 parts by mass of ion-exchanged water were charged, and the inner volume was stirred while stirring at a rate of 230 rpm under a nitrogen stream. The temperature was raised to 80 ° C. After the temperature rise, a solution in which 10 parts by mass of potassium persulfate was dissolved in 200 parts by mass of ion-exchanged water was added, and the mixture was again added dropwise over 1 hour with the following monomer and chain transfer agent at a liquid temperature of 80 ° C. did.

Styrene 480.0 parts by mass n-butyl acrylate 250.0 parts by mass Methacrylic acid 68.0 parts by mass n-octyl mercaptan (chain transfer agent) 16.4 parts by mass

  After the dropping, polymerization was performed by heating and stirring at 80 ° C. for 2 hours to prepare an amorphous resin dispersion (A) composed of a styrene / acrylic resin.

(Second stage polymerization)
A solution obtained by dissolving 7 parts by mass of sodium dodecyl sulfate in 3000 parts by mass of ion-exchanged water was charged into a 5 L reaction vessel equipped with a stirrer, a temperature sensor, a cooling pipe, and a nitrogen introduction apparatus, and heated to 98 ° C. After heating, the amorphous resin dispersion (A) made of styrene / acrylic resin prepared by the above first-stage polymerization was treated with 300 parts by mass in terms of solid content, and 90% of the following monomers, chain transfer agent and release agent were added. The mixed solution dissolved at 0 ° C. was added.

Styrene 243.0 parts by mass n-butyl acrylate 45.5 parts by mass 2-ethylhexyl acrylate 45.5 parts by mass Methacrylic acid 33.1 parts by mass n-octyl mercaptan (chain transfer agent) 5.5 parts by mass behenyl behenate (separated) Mold, melting point 73 ° C.) 130.0 parts by mass

  A mechanical dispersion machine CLEARMIX (manufactured by M Technique Co., Ltd.) having a circulation path was used for 1 hour of mixing and dispersing treatment to prepare a dispersion containing emulsified particles (oil droplets). A polymerization initiator solution in which 6 parts by mass of potassium persulfate was dissolved in 200 parts by mass of ion-exchanged water was added to this dispersion, and this system was heated and stirred at 78 ° C. for 1 hour to perform polymerization. Then, an amorphous resin dispersion (B) made of styrene / acrylic resin was prepared.

(3rd stage polymerization)
After adding 400 parts by mass of ion-exchanged water to the amorphous resin dispersion (B) made of styrene / acrylic resin obtained by the second stage polymerization and mixing well, 6.0 parts by mass of potassium persulfate was added. A solution dissolved in 400 parts by mass of ion-exchanged water was added. Furthermore, the mixed solution of the following monomer and chain transfer agent was dripped over 1 hour under the temperature conditions of 81 degreeC.

Styrene 354.8 parts by mass n-butyl acrylate 143.2 parts by mass Methacrylic acid 52.0 parts by mass n-octyl mercaptan (chain transfer agent) 8.0 parts by mass

  After completion of the dropwise addition, the mixture was heated and stirred for 2 hours, and then cooled to 28 ° C. to prepare an amorphous resin dispersion (SA1).

<Preparation of amorphous resin dispersion (SA2)>
In preparing the amorphous resin dispersion (SA1), the amorphous resin dispersion (SA2) was prepared in the same manner except that the monomer mixture used in the first stage polymerization was changed to the following. did.

Styrene 624.0 parts by mass n-butyl acrylate 120.0 parts by mass Methacrylic acid 56.0 parts by mass n-octyl mercaptan (chain transfer agent) 16.4 parts by mass

<< Preparation of Crystalline Polyester Resin Dispersion (CP1) >>
(1) Synthesis of crystalline polyester resin (1) The following monomers were placed in a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, and heated to 170 ° C. to dissolve.

Tetradecanedioic acid 450 parts by mass 1,6-hexanediol 266 parts by mass

Next, 0.8 parts by mass of Ti (OBu) ₄ was added as an esterification catalyst, heated to 235 ° C., reacted for 5 hours under normal pressure (101.3 kPa), and further for 1 hour under reduced pressure (8 kPa). went.
Subsequently, after cooling to 200 degreeC, the crystalline polyester resin 1 was obtained by making it react under reduced pressure (20 kPa) for 1 hour.
The obtained crystalline polyester resin (1) had a weight average molecular weight (Mw) of 20700 and a melting point (mp) of 74 ° C.

(2) Preparation of crystalline polyester resin dispersion (CP1) Next, 100 parts by mass of the obtained crystalline polyester resin (1) was dissolved in 400 parts by mass of ethyl acetate (manufactured by Kanto Chemical Co., Inc.) The solution was mixed with 638 parts by weight of a prepared sodium lauryl sulfate solution having a concentration of 0.26% by weight. While stirring the mixed solution, ultrasonic dispersion treatment was performed for 30 minutes at 300 μA V-LEVEL using an ultrasonic homogenizer US-150T (manufactured by Nippon Seiki Seisakusho). Then, using a diaphragm vacuum pump V-700 (manufactured by BUCHI) in a state heated to 40 ° C., ethyl acetate was completely removed while stirring for 3 hours under reduced pressure, and a crystalline polyester resin dispersion ( CP1) was prepared.
The crystalline resin particles in the crystalline polyester resin dispersion (CP1) had a volume-based median diameter (D ₅₀ ) of 160 nm.

<< Preparation of Amorphous Polyester Resin Dispersion >>
Amorphous polyester resin dispersions (AP1) to (AP4) and a hybrid amorphous polyester resin dispersion (HAP1) were prepared as follows.

<Preparation of amorphous polyester resin dispersion (AP1)>
(1) Synthesis of Amorphous Polyester Resin (1) A monomer of the following amorphous polyester resin is placed in a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, and 170 Heated to ° C to dissolve.

Fumaric acid 47.4 parts by mass Terephthalic acid 66.9 parts by mass Bisphenol A propylene oxide 2 mol adduct 228.6 parts by mass Bisphenol A ethylene oxide 2 mol adduct 57.1 parts by mass

Under stirring, 0.4 part by mass of Ti (OBu) ₄ was added as an esterification catalyst. After reacting at 235 ° C. for 6 hours under a nitrogen gas stream, the mixture was cooled to 200 ° C. and further reacted for 5 hours under reduced pressure (20 kPa), and then the solvent was removed to obtain an amorphous polyester resin (1). Got.

(2) Preparation of Amorphous Polyester Resin Dispersion (AP1) 100 parts by mass of the obtained amorphous polyester resin (1) was dissolved in 400 parts by mass of ethyl acetate (manufactured by Kanto Chemical Co., Inc.) and prepared in advance. It was mixed with 638 parts by weight of a sodium lauryl sulfate solution having a concentration of 0.26% by weight. While stirring the mixed solution, ultrasonic dispersion treatment was performed for 30 minutes at 400 μA V-LEVEL using an ultrasonic homogenizer US-150T (manufactured by Nippon Seiki Seisakusho). Then, in a state heated to 40 ° C., using a diaphragm vacuum pump V-700 (manufactured by BUCHI), ethyl acetate was completely removed while stirring for 3 hours under reduced pressure, and the solid content was 13.5 mass. % Amorphous polyester resin dispersion (AP1) was prepared.
The amorphous polyester resin particles in the amorphous polyester resin dispersion (AP1) had a volume-based median diameter (D ₅₀ ) of 102 nm.

<Preparation of amorphous polyester resin dispersion (AP2)>
100 parts by mass of the amorphous polyester resin (1) was dissolved in 400 parts by mass of ethyl acetate (manufactured by Kanto Chemical Co., Inc.) and 638 parts by mass of a 0.26% by mass sodium lauryl sulfate solution prepared in advance, Mixed. While stirring the mixed solution, ultrasonic dispersion treatment was performed for 30 minutes at 500 μA V-LEVEL using an ultrasonic homogenizer US-150T (manufactured by Nippon Seiki Seisakusho). Then, in a state heated to 40 ° C., using a diaphragm vacuum pump V-700 (manufactured by BUCHI), ethyl acetate was completely removed while stirring for 3 hours under reduced pressure, and the solid content was 13.5 mass. % Amorphous polyester resin dispersion (AP2).
The amorphous polyester resin particles in the amorphous polyester resin dispersion (AP2) had a volume-based median diameter (D ₅₀ ) of 68 nm.

<Preparation of amorphous polyester resin dispersion (AP3)>
100 parts by mass of the amorphous polyester resin (1) was dissolved in 400 parts by mass of ethyl acetate (manufactured by Kanto Chemical Co., Inc.) and 638 parts by mass of a 0.26% by mass sodium lauryl sulfate solution prepared in advance, Mixed. While stirring the mixed solution, ultrasonic dispersion treatment was performed for 30 minutes at 250 μA V-LEVEL using an ultrasonic homogenizer US-150T (manufactured by Nippon Seiki Seisakusho). Then, in a state heated to 40 ° C., using a diaphragm vacuum pump V-700 (manufactured by BUCHI), ethyl acetate was completely removed while stirring for 3 hours under reduced pressure, and the solid content was 13.5 mass. % Amorphous polyester resin dispersion (AP3) was prepared.
The amorphous polyester resin particles in the amorphous polyester resin dispersion (AP3) had a volume-based median diameter (D ₅₀ ) of 203 nm.

<Preparation of amorphous polyester resin dispersion (AP4)>
100 parts by mass of the amorphous polyester resin (1) was dissolved in 400 parts by mass of ethyl acetate (manufactured by Kanto Chemical Co., Inc.) and 638 parts by mass of a 0.26% by mass sodium lauryl sulfate solution prepared in advance, Mixed. While stirring the mixed solution, ultrasonic dispersion treatment was performed with an ultrasonic homogenizer US-150T (manufactured by Nippon Seiki Seisakusho) at V-LEVEL 550 μA for 30 minutes. Then, in a state heated to 40 ° C., using a diaphragm vacuum pump V-700 (manufactured by BUCHI), ethyl acetate was completely removed while stirring for 3 hours under reduced pressure, and the solid content was 13.5 mass. % Amorphous polyester resin dispersion (AP4) was prepared.
The amorphous polyester resin particles in the amorphous polyester resin dispersion (AP4) had a volume-based median diameter (D ₅₀ ) of 50 nm.

<Preparation of Hybrid Amorphous Polyester Resin Dispersion (HAP1)>
(1) Synthesis of Hybrid Amorphous Polyester Resin (1) A mixture of the following vinyl resin monomer, a monomer having a substituent that reacts with both the amorphous polyester resin and the vinyl resin, and a polymerization initiator Placed in dropping funnel.

Styrene 80.0 parts by mass n-butyl acrylate 20.0 parts by mass Acrylic acid 10.0 parts by mass Di-t-butyl peroxide (polymerization initiator) 16.0 parts by mass

  Further, the monomer of the following amorphous polyester resin was placed in a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, and heated to 170 ° C. to be dissolved.

Bisphenol A ethylene oxide 2 mol adduct 59.1 parts by mass Bisphenol A propylene oxide 2 mol adduct 281.7 parts by mass Terephthalic acid 63.9 parts by mass Dodecenyl succinic acid 48.4 parts by mass

Under stirring, the mixed solution placed in the dropping funnel was dropped into the four-necked flask over 90 minutes and aged for 60 minutes. Thereafter, 0.4 part by mass of Ti (OBu) ₄ was added as an esterification catalyst, the temperature was raised to 235 ° C., 5 hours under normal pressure (101.3 kPa), and 1 hour under reduced pressure (8 kPa). The reaction was performed.
Subsequently, after cooling to 200 degreeC and reacting under reduced pressure (20 kPa), solvent removal was performed and the hybrid amorphous polyester resin (1) modified | denatured with the vinyl resin was obtained.
The obtained hybrid amorphous polyester resin (1) had a weight average molecular weight (Mw) of 24,000 and an acid value of 16.2 mgKOH / g.

(2) Preparation of Hybrid Amorphous Polyester Resin Dispersion (HAP1) 72 parts by mass of the above hybrid amorphous polyester resin (1) was added to 72 parts by mass of methyl ethyl ketone and dissolved by stirring at 30 ° C. for 30 minutes. I let you. To this oil phase solution, 2.3 parts by mass of a 25% by mass aqueous sodium hydroxide solution was added and placed in a reaction vessel having a stirrer. While stirring the oil phase liquid, 252 parts by mass of ion-exchanged water at 30 ° C. was dropped over 70 minutes and mixed. During the dropping, the liquid in the container became cloudy, and after the entire amount was dropped, an emulsion in a uniform emulsified state was obtained.
By using a diaphragm vacuum pump V-700 (manufactured by BUCHI), this emulsion was heated to 60 ° C. and stirred at 15 kPa (150 mbar) under reduced pressure for 3 hours to distill off methyl ethyl ketone, and the solid content 21.5% by mass of a hybrid amorphous polyester resin dispersion (HAP1) was prepared.
The volume-based median diameter (D ₅₀ ) of the hybrid amorphous polyester resin particles in the hybrid amorphous polyester resin dispersion (HAP1) was measured with a laser diffraction particle size distribution analyzer LA-750 (manufactured by HORIBA). However, it was 99 nm.

<< Preparation of aqueous dispersion of colorant fine particles (Bk) >>
90.0 parts by mass of sodium dodecyl sulfate was added to 1600.0 parts by mass of ion-exchanged water. While stirring this solution, 420.0 parts by mass of carbon black “Regal 330R” (Cabot Corp.) is gradually added, and then dispersed using a stirring device “Clearmix” (M Technique Corp.). Thus, an aqueous dispersion (Bk) of fine colorant particles was prepared.
With respect to the aqueous dispersion (Bk) of the obtained colorant fine particles, the average particle size (volume-based median diameter (D ₅₀ )) of the colorant fine particles was 115 nm.
The volume-based median diameter (D ₅₀ ) of the aqueous dispersion of colorant fine particles (Bk) was measured using “MICROTRAC UPA-150” (manufactured by HONEYWELL).

<< Preparation of release agent particle dispersion (W1) >>
The following materials were mixed, heated to 80 ° C., and sufficiently dispersed with an Ultra Turrax T50 manufactured by IKA. Then, after carrying out a dispersion treatment with a pressure discharge type gorin homogenizer, ion exchange water was added to the dispersion to adjust the solid content to 15% to prepare a release agent particle dispersion (W1).
The volume-based median diameter (D ₅₀ ) of the release agent particles in this release agent particle dispersion (W1) was measured with a laser diffraction particle size distribution analyzer LA-750 (manufactured by HORIBA) and found to be 210 nm. It was.

Behenyl behenate (release agent, melting point 73 ° C.) 45 parts by weight Anionic surfactant (Neogen RK manufactured by Daiichi Kogyo Seiyaku) 5 parts by weight Ion-exchanged water 200 parts by weight

<Production of toner base particles>
Toner base particles (1) to (12) were produced as follows.

<Preparation of toner base particles (1)>
In a reaction vessel equipped with a stirrer, a temperature sensor and a cooling tube, 441 parts by mass of an amorphous resin dispersion (SA1) (in terms of solid content) and 55 parts by mass of a crystalline polyester resin dispersion (CP1) (in terms of solid content) , 35 parts by mass (in terms of solid content) of release agent dispersion (W1) and 2000 parts by mass of ion-exchanged water were added. The pH was adjusted to 10 by adding a 5 mol / L aqueous sodium hydroxide solution at room temperature (25 ° C.).

Further, 50 parts by mass (in terms of solid content) of an aqueous dispersion (Bk) of colorant fine particles was added, and an aqueous solution in which 60 parts by mass of magnesium chloride was dissolved in 60 parts by mass of ion-exchanged water was stirred at 30 ° C. for 10 Added over a minute. After standing for 3 minutes, the system was heated to 80 ° C. over 60 minutes, and when it reached 80 ° C., the stirring speed was adjusted so that the particle size growth rate was 0.01 μm / min. Growth was performed until the volume-based median diameter (D ₅₀ ) measured by Multisizer 3 ”(manufactured by Coulter Beckman) was 6.0 μm.

  Furthermore, 50 parts by mass (converted to solid content) of amorphous polyester resin dispersion (AP1) was added, and when the supernatant of the liquid became transparent, 190 parts by mass of sodium chloride was dissolved in 760 parts by mass of ion-exchanged water. The aqueous solution was added to stop particle size growth. Further, the temperature was raised and the mixture was stirred at 80 ° C., particle fusion proceeded until the average circularity of the toner particles reached 0.970, and the toner particles were cooled to 30 ° C.

  Subsequently, the operation of solid-liquid separation and re-dispersion of the dehydrated toner cake in ion-exchanged water and solid-liquid separation was washed three times, followed by drying at 40 ° C. for 24 hours, whereby toner base particles (1) were obtained. Produced.

<Preparation of toner base particles (2)>
Toner base particles (2) were prepared in the same manner as in the preparation of toner base particles (1), except that the amorphous polyester resin dispersion (AP1) was changed to the amorphous polyester resin dispersion (AP2).

<Preparation of toner base particles (3)>
Toner base particles (3) were prepared in the same manner as in the preparation of toner base particles (1) except that the amorphous polyester resin dispersion (AP1) was changed to an amorphous polyester resin dispersion (AP3).

<Preparation of toner base particles (4)>
Toner base particles (4) were prepared in the same manner as in the preparation of the toner base particles (1) except that the amorphous polyester resin dispersion (AP1) was changed to the amorphous polyester resin dispersion (AP4).

<Preparation of toner base particles (5)>
In the production of the toner base particles (1), the addition amount of the crystalline polyester resin dispersion (CP1) is 61 parts by mass (in terms of solid content), and the addition amount of the amorphous polyester resin dispersion (AP1) is 108 parts by mass ( A toner base particle (5) was produced in the same manner except that the solid content was calculated.

<Preparation of toner base particles (6)>
In the production of the toner base particles (3), the addition amount of the crystalline polyester resin dispersion (CP1) is 66 parts by mass (in terms of solid content), and the addition amount of the amorphous polyester resin dispersion (AP3) is 140 parts by mass ( A toner base particle (6) was prepared in the same manner except that the solid content was calculated.

<Preparation of toner base particles (7)>
Toner base particles (7) were prepared in the same manner as in the preparation of toner base particles (3) except that the amount of the amorphous polyester resin dispersion (AP3) added was 32 parts by mass.

<Preparation of toner base particles (8)>
Toner base particles (8) were prepared in the same manner as in the preparation of toner base particles (1) except that the amount of the crystalline polyester resin dispersion (CP1) added was 26 parts by mass (in terms of solid content).

<Preparation of toner base particles (9)>
Toner base particles (9) were prepared in the same manner as in the preparation of toner base particles (1) except that the amount of the crystalline polyester resin dispersion (CP1) added was 88 parts by mass (in terms of solid content).

<Preparation of toner base particles (10)>
Toner base particles (10) were prepared in the same manner as in the preparation of toner base particles (1), except that the amorphous polyester resin dispersion (AP1) was changed to a hybrid amorphous polyester resin dispersion (HAP1). .

<Preparation of toner base particles (11)>
Toner base particles (11) were prepared in the same manner as in the preparation of toner base particles (1) except that the crystalline polyester resin dispersion (CP1) was not added.

<Preparation of toner base particles (12)>
Toner base particles (12) were prepared in the same manner as in the preparation of toner base particles (1) except that the amorphous polyester resin dispersion (AP1) was changed to an amorphous resin dispersion (SA2).

《Average long side length of protrusions》
In the SEM image data when the produced toner base particles (1) to (12) are observed 10,000 times with a scanning electrophotographic microscope (SEM) “JSM-7401F” (manufactured by JEOL Ltd.), The portions where the distance between the two parallel lines becomes the maximum when the contour lines are sandwiched between the two parallel lines when the contour lines are sandwiched between the two parallel lines. The long side length of the particle was used. In the measurement, the long side length of 20 convex portions having a long side length of 30 nm or more is measured, the same measurement is performed on five toner base particles, and the average value thereof is calculated as the average long side length of the convex portion. did.
The measurement results are shown in Table I.

《Average distance between convex parts》
For each of the produced toner base particles (1) to (12), in the SEM image data observed at a magnification of 10,000, the four convex portions are picked up from the individual convex portions in the order closer to the convex portion. The average of the shortest distances from the outer periphery of the convex portion to the outer periphery of the four convex portions picked up was defined as the interval between the convex portions. In the measurement, the interval between the convex portions measured around the convex portion having a long side length of 30 nm or more is measured for 20 convex portions, the same measurement is performed for five toner base particles, and the average value thereof is calculated. It was set as the average space | interval of a convex part. The long side length of the four convex portions to be picked up is not limited.
The measurement results are shown in Table I.

<< Average distribution density of convex parts >>
For each of the produced toner base particles (1) to (12), in the SEM image data observed at a magnification of 10,000, the number of convex portions having a long side length of 30 nm or more per 1 μm ^{2 of} 10 toner base particles is measured. The average value was made into the average distribution density of a convex part.
The measurement results are shown in Table I.

  In the toner base particles (12), no protrusions were observed on the surface.

<< Production of alumina particles (external additive) >>
Alumina particles (1) to (3) were produced as follows.

<Production of alumina particles (1)>
320 kg / h of aluminum trichloride (AlCl ₃ ) was evaporated in an evaporator at about 200 ° C. and chloride vapor was passed through the mixing chamber of the burner with nitrogen. Here, the gas stream was mixed with hydrogen 100 Nm ³ / h and air 450 Nm ³ / h and fed to the flame via a central tube (diameter 7 mm). The burner temperature was 300 ° C., and the tube discharge speed was about 39.8 m / s. Hydrogen 0.05 Nm ³ / h was supplied as a jacket type gas via the outer tube. The gas combusted in the reaction chamber and was cooled to about 110 ° C. in the downstream agglomeration zone. There, the primary particles of alumina were agglomerated.
At the same time, the alumina particles are separated from the hydrochloric acid-containing gas produced in the filter, and the powder having wet air is treated at about 500 to 700 ° C. to remove the adhesive chloride, and the alumina particles (1) are removed. Produced.

  The obtained alumina particles (1) were observed with an SEM “JSM-7401F” (manufactured by JEOL Ltd.) 50000 times, and the SEM image data was captured by a scanner, and an image processing analyzer “LUZEX AP” (Nireco) In the SEM image, the alumina particles in the SEM image were binarized, the horizontal ferret diameter for 100 alumina particles was calculated, and the average value was the number average particle diameter, which was 25 nm.

<Preparation of alumina particles (2)>
Alumina particles (2) were produced in the same manner as in the production of alumina particles (1) except that the tube discharge speed was about 43.5 m / s.
The number average particle diameter of the obtained alumina particles (2) was 10 nm.

<Preparation of alumina particles (3)>
Alumina particles (3) were produced in the same manner as in the production of alumina particles (1) except that the tube discharge speed was about 30.9 m / s.
The number average particle diameter of the obtained alumina particles (3) was 55 nm.

<Production of toner>
Toners (1) to (18) were produced as follows.

<Preparation of Toner (1)>
The following materials were added to a Henschel mixer “FM20C / I” (manufactured by Nihon Coke Kogyo Co., Ltd.), and the rotational speed was set so that the blade tip peripheral speed was 50 m / sec and mixed for 25 minutes. The product temperature at the time of mixing is set to 40 ° C. ± 1 ° C. When the temperature reaches 41 ° C., the cooling water is supplied to the outer bath of the Henschel mixer at a flow rate of 5 L / min to 39 ° C. In this case, the temperature inside the Henschel mixer was controlled by flowing cooling water at 1 L / min.

Toner base particles (1) 100 parts by mass Silica particles 1 (number average primary particle size = 110 nm, hydrophobicity = 72) 0.3 parts by mass Silica particles 2 (number average primary particle size = 12 nm, hydrophobicity = 67) 0.8 part by mass Alumina particles (1) 1.0 part by mass

  After the external additive treatment step, toner (1) was produced by removing coarse particles using a sieve having an opening of 45 μm.

<Production of Toners (2) to (9), (15), (16) and (18)>
In the production of the toner (1), the toners (2) to (9), (15), (16) are the same except that the toner base particles (1) are changed to toner base particles (2) to (11), respectively. ) And (18) were produced.

<Production of Toners (10) and (11)>
Toners (10) and (11) were produced in the same manner as in the production of toner (1), except that alumina particles (1) were changed to alumina particles (2) and (3), respectively.

<Production of Toners (12) to (14)>
In the production of the toner (1), toners (12) to (12) to ( 14) was produced.

<Preparation of Toner (17)>
Toner (1) was prepared in the same manner except that 2.0 parts by mass of titania particles (number average primary particle size = 25 nm, hydrophobicity = 75) were added instead of alumina particles (1). 17) was produced.

<Measurement of softening point>
The softening point of each of the produced toners (1) to (18) was measured.
The softening point temperature was measured using a flow tester “CFT-500D” (manufactured by Shimadzu Corporation).
Specifically, in an environment of a temperature of 20 ± 1 ° C. and a humidity of 50 ± 5% RH, 1.1 g of toner is put in a petri dish and flattened and left to stand for 12 hours or more, and then the molding machine “SSP-10A” ( By Shimadzu Corporation) with a force of 3820 kg / cm ² for 30 seconds to produce a cylindrical molded sample having a diameter of 1 cm. Next, this molded sample was subjected to a load tester “CFT-500D” (manufactured by Shimadzu Corporation) under a temperature of 24 ± 5 ° C. and a humidity of 50 ± 20% RH, with a load of 196 N (20 kgf), a starting temperature of 60 ° C., and a preheating time. It was extruded from the end of preheating using a 1 cm diameter piston from a hole (1 mm diameter × 1 mm) in a cylindrical die under the condition of a temperature rising rate of 6 ° C./min for 300 seconds. The offset method temperature T _offset measured at a setting of an offset value of 5 mm by the melting temperature measurement method of the temperature rising method was used as the softening point of the toner.
The measurement results are shown in Table I.

<Production of developer>
For each of the produced toners (1) to (18), a ferrite carrier having a volume average particle size of 30 μm and coated with a copolymer resin of cyclohexyl methacrylate and methyl methacrylate (monomer mass ratio = 1: 1) has a toner concentration of 6. Developers (1) to (18) were prepared by mixing the mixture so as to be in mass%.

<Evaluation>
<Measurement of sticking force>
Each of the above-prepared developers (1) to (18) was loaded on “bizhub PRESS C1070 (manufactured by Konica Minolta)”, and the sticking force was measured.
Specifically, in an environment of normal temperature and normal humidity (temperature 20 ° C., humidity 50% RH), the toner adhesion amount on the “OK top coat paper 157 g / m ² ” (manufactured by Oji Paper Co., Ltd.) is 8.0 g / After setting to m ² , the lower roller temperature was set to 70 ° C., and 5 single-sided images were output in A3 size in the double-sided output mode. 500 sheets of A3 J paper were placed on the output paper bundle and left for 2 hours. Placed on a flat table, a tape T was affixed to the tip of the uppermost sheet S and slid slowly in the horizontal direction H.
At this time, the sheet lower than the second sheet from the top is fixed to the table so as not to move. The force required to slide the paper was measured with a spring alone. This measurement was repeated 4 times in order from the top, and the average value of the force indicated by the spring was used as the sticking force. When the sticking force was 2.0 N or less, the practical level was set.
The measurement results are shown in Table I.

  In Table I, the content of the crystalline polyester resin means all resins contained in the toner base particles, for example, in the toner (1), the amorphous resin (SA1), the crystalline polyester resin (CP1), and The ratio with respect to the total mass (100 mass%) of an amorphous polyester resin (AP1) is shown.

<Summary>
As apparent from Table I, it can be seen that the toners (1) to (15) of the present invention have a smaller sticking force than the toners (16) to (18) of the comparative examples.
As described above, the toner base particles include a toner base particle precursor containing an amorphous resin and a crystalline polyester resin, and a plurality of convex portions formed on the surface of the toner base particle precursor. It was confirmed that inclusion of alumina particles as an additive is useful for suppressing electrostatic sticking.

DESCRIPTION OF SYMBOLS 10 Toner base particle 11 Toner base particle precursor 12 Convex part 101 Toner base particle precursor resin 101a Amorphous resin 101b Crystalline polyester resin 102 Convex part resin 102a Vinyl polymer segment 102b Polyester polymer segment X Long side length Y1-Y4 shortest distance

Claims (7)

A toner for developing an electrostatic image containing toner particles having an external additive on the surface of the toner base particles,
The toner base particles include a toner base particle precursor containing an amorphous resin and a crystalline polyester resin, and a plurality of protrusions formed on the surface of the toner base particle precursor.
An electrostatic charge image developing toner comprising alumina particles as the external additive.   The electrostatic image developing toner according to claim 1, wherein the convex portion contains an amorphous polyester resin.   The electrostatic image developing toner according to claim 1, wherein an average long side length of the convex portion is in a range of 100 to 300 nm.   4. The electrostatic image developing toner according to claim 1, wherein an average interval between the convex portions is in a range of 20 to 200 nm. 5.   5. The electrostatic charge image developing toner according to claim 1, wherein the number average particle diameter of the alumina particles is in the range of 5 to 60 nm.   The content of the alumina particles in the toner particles is in the range of 0.1 to 2.0 parts by mass with respect to 100 parts by mass of the toner base particles. The toner for developing an electrostatic image according to any one of the above.   The content of the crystalline polyester resin is in the range of 3 to 20% by mass with respect to the total mass (100% by mass) of the resin contained in the toner base particles. Item 7. The electrostatic image developing toner according to any one of Items 6 to 6.