JP2017125958A - Toner for electrostatic latent image development and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide toner for electrostatic latent image development that is excellent in low-temperature fixability and heat-resistant storage property, and can continue forming high-quality images while suppressing toner fastening even when used for continuous printing.SOLUTION: Toner particles 10 included in toner for electrostatic latent image development each include a toner base particle 11 containing a binder resin and spherical resin particles 12 adhered to the surface of the toner base particle 11. In a peripheral area of the resin particle 12, a surface layer part of the toner base particle 11 is raised toward the resin particle 12. A diameter D1 of the resin particle 12, a diameter D2 of the peripheral area of the resin particle 12 where the surface layer part of the toner base particle 11 is raised, and a height difference ΔH between the height at which the surface layer part of the toner base particle 11 is started to be raised and the maximum height of the resin particle 12 satisfy all the relationship of the formula 1, relationship of the formula 2, and relationship of the formula 3. Formula 1: 50nm≤D1≤150nm, formula 2: (2×D1)≤D2, and formula 3: 1.00<(ΔH/D1)≤1.50.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a toner for developing an electrostatic latent image and a method for producing the same, and more particularly to a toner for developing an electrostatic latent image including a plurality of toner particles including an external additive and a method for producing the same.

  Patent Document 1 discloses a technique of embedding adhered particles (external additives) from the surface of the center particle to the inside.

JP 2012-68325 A

  However, the technology disclosed in Patent Document 1 alone is excellent in both low-temperature fixability and heat-resistant storage stability, and is capable of continuing to form a high-quality image when used for continuous printing. It is difficult to obtain a toner for image development.

  The present invention has been made in view of the above circumstances, and has excellent low-temperature fixability and heat-resistant storage stability. Even when used for continuous printing, toner fixation (more specifically, toner fixation to a developing sleeve, An object of the present invention is to provide an electrostatic latent image developing toner capable of continuously forming a high-quality image while suppressing toner sticking to the photosensitive drum, and the like, and a method for producing the same.

The electrostatic latent image developing toner according to the present invention includes a plurality of toner particles including toner base particles and spherical resin particles. The toner base particles contain a binder resin. The resin particles are attached to the surface of the toner base particles. In the peripheral region of the resin particles, the surface layer portion of the toner base particles rises toward the resin particles. The diameter D1 of the resin particle, the diameter D2 of the peripheral region of the resin particle where the surface layer portion of the toner base particle is rising, the rising start height of the surface layer portion of the toner base particle, and the maximum of the resin particle The height difference ΔH with respect to the height satisfies all of the relationship of Equation 1, the relationship of Equation 2, and the relationship of Equation 3.
Formula 1: 50 nm ≦ D1 ≦ 150 nm
Formula 2: (2 × D1) ≦ D2
Formula 3: 1.00 <(ΔH / D1) ≦ 1.50

  The method for producing a toner for developing an electrostatic latent image according to the present invention is a method for producing the toner for developing an electrostatic latent image according to the present invention. The method for producing a toner for developing an electrostatic latent image includes preparing resin particles and forming a raised portion. In the preparation of the resin particles, the toner base particles and the resin particles are prepared. In the formation of the raised portion, the toner base particles and the resin particles are mixed using a mixer equipped with a stirring blade, so that the surface layer portion of the toner base particles has the relationship of Formula 1 and Formula 2 above. And a rising portion that satisfies all of the relationship of Equation 3 above.

  According to the present invention, it has excellent low-temperature fixability and heat-resistant storage stability, and even when used for continuous printing, toner fixation (more specifically, toner fixation to a developing sleeve, toner adhesion to a photosensitive drum, etc.) It is possible to provide a toner for developing an electrostatic latent image that can continue to form a high-quality image and a method for manufacturing the same.

FIG. 3 is a diagram illustrating an example of toner particles contained in an electrostatic latent image developing toner according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view showing a part of toner particles shown in FIG. 1. FIG. 2 is an enlarged plan view showing a part of toner particles shown in FIG. 1. It is a figure which shows the cross-sectional shape measured by SPM (scanning probe microscope) about an example of the toner particle contained in the electrostatic latent image developing toner according to the embodiment of the present invention.

  An embodiment of the present invention will be described. Note that the evaluation results (values indicating shape, physical properties, etc.) regarding the powder (more specifically, toner base particles, external additives, toner, etc.) are average values from the powder unless otherwise specified. It is the number average of the values measured for each of these average particles by selecting a significant number of particles.

The number average particle diameter of the powder is the number average value of the equivalent circle diameter of primary particles (diameter of a circle having the same area as the projected area of the particles) measured using a microscope unless otherwise specified. . Unless otherwise specified, the volume median diameter (D _v50 ) and the number median diameter (D _n50 ) of the powder are “Coulter Counter Multisizer 3” manufactured by Beckman Coulter, Inc. Is a value measured based on the Coulter principle (pore electrical resistance method). Moreover, the measured value of the volume average particle diameter (MV) of the powder is a laser diffraction / scattering type particle size distribution measuring device (“LA-750” manufactured by Horiba, Ltd.) unless otherwise specified. It is the value measured using. In addition, the measurement value of the circularity (= peripheral length of a circle equal to the projected area of the particle / peripheral length of the particle) is not specified, the flow particle image analyzer (“FPIA (registered trademark)” manufactured by Sysmex Corporation) ) -3000 ") is the number average of the values measured for a substantial number (eg 3000) of particles. Moreover, each measured value of an acid value and a hydroxyl value is a value measured according to "JIS (Japanese Industrial Standard) K0070-1992" unless otherwise specified. Moreover, each measured value of a number average molecular weight (Mn) and a mass average molecular weight (Mw) is the value measured using the gel permeation chromatography, if not prescribed | regulated at all. Further, the SP value is a value calculated according to the Fedors calculation method (R. F. Fedors, “Polymer Engineering and Science”, 1974, Vol. 14, No. 2, p147-154) unless otherwise specified. (Unit: (cal / cm ³ ) ^1/2 ). The SP value is represented by the formula “SP value = (E / V) ^1/2 ” (E: molecular cohesive energy [cal / mol], V: molecular volume [cm ³ / mol]).

  Hereinafter, a compound and its derivatives may be generically named by adding “system” after the compound name. When the name of a polymer is expressed by adding “system” after the compound name, it means that the repeating unit of the polymer is derived from the compound or a derivative thereof. Acrylic and methacrylic are sometimes collectively referred to as “(meth) acrylic”.

  The toner according to the exemplary embodiment can be suitably used for developing an electrostatic latent image, for example, as a positively chargeable toner. The toner of the present exemplary embodiment is a powder that includes a plurality of toner particles (each having a configuration described later). The toner may be used as a one-component developer. Further, a two-component developer may be prepared by mixing a toner and a carrier using a mixing device (more specifically, a ball mill or the like). In order to form a high-quality image, it is preferable to use a ferrite carrier as a carrier. In order to form a high-quality image over a long period of time, it is preferable to use magnetic carrier particles including a carrier core and a resin layer covering the carrier core. In order to impart magnetism to the carrier particles, the carrier particles may be formed of a magnetic material, or the carrier particles may be formed of a resin in which the magnetic particles are dispersed. Further, magnetic particles may be dispersed in the resin layer covering the carrier core. In order to form a high-quality image, the amount of toner in the two-component developer is preferably 5 parts by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the carrier. The positively chargeable toner contained in the two-component developer is positively charged by friction with the carrier.

  The toner according to the exemplary embodiment can be used for image formation in, for example, an electrophotographic apparatus (image forming apparatus). Hereinafter, an example of an image forming method using an electrophotographic apparatus will be described.

  First, an electrostatic latent image is formed on a photoconductor (for example, a surface layer portion of a photoconductor drum) based on image data. Next, the formed electrostatic latent image is developed using a developer containing toner. In the developing process, toner (for example, toner charged by friction with a carrier or blade) on a developing sleeve (for example, a surface layer portion of a developing roller in the developing device) disposed in the vicinity of the photosensitive member is converted into an electrostatic latent image. A toner image is formed on the photoreceptor by adhering. In the subsequent transfer step, the toner image on the photosensitive member is transferred to an intermediate transfer member (for example, a transfer belt), and then the toner image on the intermediate transfer member is further transferred to a recording medium (for example, paper). Thereafter, the toner is heated to fix the toner on the recording medium. As a result, an image is formed on the recording medium. For example, a full color image can be formed by superposing four color toner images of black, yellow, magenta, and cyan.

The toner according to the exemplary embodiment is an electrostatic latent image developing toner having the following configuration (hereinafter referred to as a basic configuration).
(Basic toner configuration)
The toner for developing an electrostatic latent image includes a plurality of toner particles including toner base particles containing a binder resin and spherical resin particles. The resin particles are attached to the surface of the toner base particles. In the peripheral region of the resin particles, the surface layer portion of the toner base particles rises toward the resin particles. The diameter D1 of the resin particle, the diameter D2 of the peripheral region of the resin particle where the surface layer portion of the toner base particle is raised (hereinafter, simply referred to as the peripheral region), and the surface layer portion of the toner base particle are raised Difference in height between the starting height (hereinafter referred to as the rising start height H0) and the maximum height of the resin particles (hereinafter referred to as the maximum height H2) (hereinafter referred to as the rising height difference ΔH) Satisfies all of the following relationships of Equation 1, Equation 2, and Equation 3.
Formula 1: 50 nm ≦ D1 ≦ 150 nm
Formula 2: (2 × D1) ≦ D2
Formula 3: 1.00 <(ΔH / D1) ≦ 1.50
In the case where the shape of the resin particles is not a true sphere, the diameter D1 of the resin particles is determined when the toner particles are viewed from the outside toward the center using a microscope (more specifically, along the normal line of the toner mother particles). This corresponds to the equivalent circle diameter of the resin particles. In other words, the diameter D1 of the resin particle corresponds to the diameter of a circle having the same area as the projected area of the resin particle projected onto the tangent plane of the toner base particle. Further, when the shape of the peripheral region is not a perfect circle, the diameter D2 of the peripheral region corresponds to the equivalent circle diameter.

  The above-mentioned rising portion (portion where the surface layer portion of the toner base particles rises toward the resin particles) in the connection portion between the toner base particles and the resin particles is, for example, external addition of the resin particles to the toner base particles. It can be formed by performing under temperature conditions that are not too low and not too high with respect to the glass transition point (Tg) of the surface layer portion (mainly binder resin) of the particles. Specifically, the temperature is 5 ° C. or more lower than Tg of the binder resin of the toner base particles, and 30 ° C. or more is not lower (Tg−30 ° C. <external addition temperature ≦ Tg−5 ° C.). When the adding step is performed, the raised portion is easily formed. When there are a plurality of raised portions on one toner particle, the success or failure of each of the expressions 1 to 3 is determined based on the number average value of each parameter measured for a considerable number of raised portions. . For example, the success or failure of the relationship of Formula 1 is determined based on the number average value of D1. The success or failure of the relationship of Formula 2 is determined based on the number average value of (2 × D1) and the number average value of D2. The success or failure of the relationship of Formula 3 is determined based on the number average value of (ΔH / D1).

  The toner having the above basic structure is excellent in low-temperature fixability and heat-resistant storage stability, and even when used for continuous printing, toner fixation (more specifically, toner fixation to the developing sleeve and toner adhesion to the photosensitive drum). The inventor has found that high-quality images can be continuously formed while suppressing sticking and the like. Since the diameter D2 of the peripheral region is sufficiently larger than the diameter D1 of the resin particles, the binder resin in the toner base particles and the resin constituting the resin particles exhibit excellent compatibility in the rising portion, and these There is a tendency for the resin to be integrated. When such resin integration occurs, the heat resistant storage stability and adhesion resistance of the toner are improved. Rather than the structure in which the resin particles are deformed to form convex portions on the surface of the toner base particles, the surface layer portion (specifically, the binder resin) of the toner base particles rises toward the resin particles and is integrated with the resin particles. The inventor has found that the configuration (the above basic configuration) significantly improves the heat-resistant storage stability and adhesion resistance of the toner. In the toner having the above basic configuration, most of the resin particles (for example, 90% by number or more) tend to be fixed as primary particles (without aggregation).

  Further, when the rising height difference ΔH is sufficiently large with respect to the diameter D1 of the resin particles, the resin particles easily function as spacers between the toner particles. Since the resin particles function as spacers, toner aggregation can be suppressed. By suppressing the aggregation of the toner, it is considered that the heat resistant storage stability and adhesion resistance of the toner are improved.

  If the diameter D1 of the resin particles is too large, the low-temperature fixability of the toner tends to deteriorate. When the diameter D1 of the resin particles is too small, the heat resistant storage stability and adhesion resistance of the toner tend to be deteriorated. If the rising height difference ΔH is too large with respect to the diameter D1 of the resin particles, the resin particles tend to be fixed in an aggregated state (that is, as secondary particles). When the resin particles are fixed as secondary particles (aggregated particles), the heat resistant storage stability and adhesion resistance of the toner tend to be deteriorated. If the rising height difference ΔH is too small with respect to the diameter D1 of the resin particles, the heat resistant storage stability and adhesion resistance of the toner tend to deteriorate. When the diameter D2 of the peripheral region is too small with respect to the diameter D1 of the resin particles, the heat resistant storage stability and adhesion resistance of the toner tend to be deteriorated.

  Hereinafter, an example of the configuration of toner particles contained in the toner having the above basic configuration will be described with reference to FIGS. FIG. 1 is a diagram illustrating an example of the configuration of toner particles contained in the toner according to the present embodiment. FIG. 2 is an enlarged sectional view showing a part of the toner particles shown in FIG. FIG. 3 is an enlarged plan view showing a part of the toner particles shown in FIG. 2 and 3, arrows X1, X2, Y1, Y2, Z1, and Z2 indicate six directions related to three axes (X axis, Y axis, and Z axis) orthogonal to each other. 2 and 3, the Z axis corresponds to the normal line of the toner base particles 11, and the XY plane corresponds to the tangential plane of the toner base particles 11.

  As shown in FIG. 1, the toner particles 10 include toner base particles 11. Further, the toner particle 10 includes a plurality of spherical resin particles 12 as external additives. Each of the resin particles 12 is attached to the surface of the toner base particles 11. In the peripheral region of the resin particle 12, as shown in FIGS. 2 and 3, a part of the surface layer portion (the rising portion R <b> 12) of the toner base particle 11 is raised toward the resin particle 12. The surface layer portion of the toner base particles 11 has a raised portion R12 and a portion other than the raised portion R12 (non-raised portion R11).

  In FIG. 2, the rising start height H0 is the rising start height of the surface layer portion of the toner base particles 11 (the height of the rising start portion P11 located at the boundary between the non-lifting portion R11 and the rising portion R12). ). The rising height H0 coincides with the height of the surface of the non-raised portion R11. Further, the maximum height H2 indicates the height of the highest portion (the top portion P22) of the resin particles 12. In FIG. 2, the difference in height between the rising start height H0 and the maximum height H2 is shown as a rising height difference ΔH. The particle height H1 indicates the height of the lowest part (bottom part P21) of the resin particles 12. The resin particles 12 are lifted from the surface of the non-raised portion R11 by a difference (H1-H0) between the rising start height H0 and the particle height H1.

  In FIG. 2, the height at the same distance as each of the particle height H1 and the maximum height H2 is shown as a center height H12. That is, the distance ΔH1 from the center height H12 to the particle height H1 is equal to the distance ΔH2 from the center height H12 to the maximum height H2. In the example of FIG. 2, the height of the highest portion of the rising portion R12 (the rising end portion P12) is substantially coincident with the center height H12. Since the height of the rising end portion P12 substantially coincides with the center height H12, the position of the resin particles 12 is easily stabilized. However, the height of the rising end portion P12 may be higher than the center height H12 or lower than the center height H12.

  In the toner having the basic configuration described above, the diameter D1 of the resin particles is 50 nm or more and 150 nm or less so as to satisfy the above-described formula 1. The diameter D1 of the resin particles corresponds to the equivalent circle diameter of the resin particles 12 when the toner particles are viewed from the outside (Z2 side) toward the center (Z1 side) (that is, along the Z axis) using a microscope. To do. The diameter D1 of the resin particle is a diameter of a circle having the same area as the projected area of the resin particle 12 (see FIG. 3) that is normally projected onto the tangential plane (XY plane) of the toner base particle 11.

  In the toner having the basic configuration described above, the diameter D2 of the peripheral region of the resin particle 12 rising toward the resin particle 12 is more than twice the diameter D1 of the resin particle 12 so as to satisfy the above-described formula 2. Become. The diameter D2 of the peripheral region is the equivalent circle diameter of the raised portion R12 when the toner particles are viewed from the outside (Z2 side) to the center (Z1 side) (that is, along the Z axis) using a microscope. Equivalent to. The diameter D2 of the peripheral region is a diameter of a circle having the same area as the projected area of the raised portion R12 (see FIG. 3) that is orthographically projected onto the tangential plane (XY plane) of the toner base particles 11.

  In the toner having the basic configuration described above, the rising height difference ΔH (= H2−H0) is more than 1.00 times and less than 1.50 times the diameter D1 of the resin particles 12 so as to satisfy the above-described Expression 3. .

  FIG. 4 is a diagram illustrating a cross-sectional shape of an example of toner particles contained in the toner according to the present embodiment, which is measured with an SPM (scanning probe microscope). The SPM measurement conditions were the same as in the examples described later. FIG. 4 shows a cross-sectional shape of the toner particles measured by SPM (specifically, a cross-sectional shape of the resin particle 12 and the rising portion R12 shown in FIG. 2).

  The toner according to the present embodiment includes a plurality of toner particles (hereinafter, referred to as toner particles according to the present embodiment) defined by the basic configuration described above. The toner containing a plurality of toner particles of this embodiment is considered to be excellent in low-temperature fixability and heat-resistant storage stability (see Tables 1 and 2 described later). In addition, when continuous printing is performed using a toner including a plurality of toner particles according to the present exemplary embodiment, toner adhesion (more specifically, toner adhesion to the developing sleeve, toner adhesion to the photosensitive drum, and the like) is suppressed. It is considered that high-quality images can be continuously formed (see Tables 1 and 2 described later). In order to achieve such an effect, the toner preferably contains the toner particles of this embodiment in a proportion of 80% by number or more, and more preferably contains the toner particles of this embodiment in a proportion of 90% by number or more. It is more preferable that the toner particles of the present exemplary embodiment are included at a ratio of 100% by number.

  In order to maintain the excellent properties of the toner over a long period of time, the change rate of the BET specific surface area of the toner particles should be less than 1.0% before and after the toner is allowed to stand for 3 hours at a temperature of 80 ° C. preferable. In such a toner, it is considered that the binder resin in the toner base particles and the resin constituting the resin particles are sufficiently integrated in the above-described rising portion.

In order to maintain excellent toner characteristics over a long period of time, the SP value of the binder resin in the toner base particles (hereinafter referred to as SP _A ) and the SP value of the resin constituting the resin particles (hereinafter referred to as SP _B). Is preferably 0.2 (cal / cm ³ ) ^1/2 or less. In such a toner, it is considered that the binder resin in the toner base particles and the resin constituting the resin particles are easily integrated in the above-described rising portion. Incidentally, it may be larger in the SP _B than SP _A, may be greater in the SP _A than SP _B.

  In order to form a high-quality image using the toner according to this embodiment, the circularity of the toner base particles is preferably 0.935 or more and less than 0.980.

In order to achieve both heat-resistant storage stability and low-temperature fixability of the toner according to the exemplary embodiment, it is preferable that the volume median diameter (D _v50 ) of the toner base particles is 3 μm or more and 7 μm or less.

Resins suitable for forming toner particles are as follows.
<Preferable thermoplastic resin>
Examples of the thermoplastic resin constituting the toner particles (particularly, toner base particles) include styrene resins, acrylic acid resins (more specifically, acrylic ester polymers or methacrylic ester polymers), olefins, and the like. Resin (more specifically, polyethylene resin or polypropylene resin), vinyl resin (more specifically, vinyl chloride resin, polyvinyl alcohol, vinyl ether resin, or N-vinyl resin), polyester resin, polyamide resin, Or a urethane resin can be used conveniently. A copolymer of each of these resins, that is, a copolymer in which an arbitrary repeating unit is introduced into the resin (specifically, a styrene-acrylic acid resin or a styrene-butadiene resin) is also used as a toner. It can be suitably used as a thermoplastic resin constituting the particles.

  The thermoplastic resin can be obtained by addition polymerization, copolymerization, or condensation polymerization of one or more thermoplastic monomers. The thermoplastic monomer is a monomer that becomes a thermoplastic resin by homopolymerization (more specifically, an acrylic acid monomer or a styrene monomer), or a monomer that becomes a thermoplastic resin by condensation polymerization (for example, by condensation polymerization). Alcohol and carboxylic acid to be polyester resin).

  The styrene-acrylic acid resin is a copolymer of one or more styrene monomers and one or more acrylic monomers. In order to synthesize a styrene-acrylic acid resin, for example, a styrene monomer and an acrylic acid monomer as shown below can be suitably used. By using an acrylic acid monomer having a carboxyl group, a carboxyl group can be introduced into the styrene-acrylic acid resin. Further, by using a monomer having a hydroxyl group (more specifically, p-hydroxystyrene, m-hydroxystyrene, (meth) acrylic acid hydroxyalkyl ester, or the like), the hydroxyl group can be introduced into the styrene-acrylic acid resin. .

  Preferable examples of the styrene monomer include styrene, alkyl styrene (more specifically, α-methyl styrene, p-ethyl styrene, 4-tert-butyl styrene, etc.), p-hydroxy styrene, m-hydroxy styrene. , Vinyl toluene, α-chlorostyrene, o-chlorostyrene, m-chlorostyrene, or p-chlorostyrene.

  Preferable examples of the acrylic acid monomer include (meth) acrylic acid, (meth) acrylic acid alkyl ester, or (meth) acrylic acid hydroxyalkyl ester. Suitable examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, iso-propyl (meth) acrylate, and (meth) acrylic. Examples include n-butyl acid, iso-butyl (meth) acrylate, or 2-ethylhexyl (meth) acrylate. Suitable examples of the (meth) acrylic acid hydroxyalkyl ester include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, or (meth) acrylic. The acid 4-hydroxybutyl is mentioned.

  The polyester resin is obtained by polycondensing one or more alcohols and one or more carboxylic acids. As the alcohol for synthesizing the polyester resin, for example, dihydric alcohols (more specifically, diols or bisphenols) as shown below or trihydric or higher alcohols can be suitably used. As the carboxylic acid for synthesizing the polyester resin, for example, divalent carboxylic acids or trivalent or higher carboxylic acids as shown below can be suitably used.

  Suitable examples of diols include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, Examples include 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, di1,2-propanediol, polyethylene glycol, poly1,2-propanediol, or polytetramethylene glycol.

  Preferable examples of the bisphenol include bisphenol A, hydrogenated bisphenol A, bisphenol A ethylene oxide adduct, or bisphenol A propylene oxide adduct.

  Preferable examples of trihydric or higher alcohols include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butane. Triol, 1,2,5-pentanetriol, glycerol, diglycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, or 1,3,5- Trihydroxymethylbenzene is mentioned.

  As preferable examples of the divalent carboxylic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, adipic acid, sebacic acid, azelaic acid, malonic acid Succinic acid, alkyl succinic acid (more specifically, n-butyl succinic acid, isobutyl succinic acid, n-octyl succinic acid, n-dodecyl succinic acid, isododecyl succinic acid, etc.), or alkenyl succinic acid (more specific Specifically, n-butenyl succinic acid, isobutenyl succinic acid, n-octenyl succinic acid, n-dodecenyl succinic acid, or isododecenyl succinic acid, etc.) may be mentioned.

  Preferred examples of the trivalent or higher carboxylic acid include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) Examples include methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, or empole trimer acid.

  The toner particles contained in the toner may be toner particles not having a shell layer (hereinafter referred to as non-capsule toner particles) or toner particles having a shell layer (hereinafter referred to as capsule toner particles). There may be. In the capsule toner particles, the toner base particles include a core and a shell layer that covers the surface of the core. The shell layer corresponds to the surface layer portion of the toner base particles. In order for the toner to have the above basic configuration, the shell layer preferably contains a thermoplastic resin (more specifically, the “preferable thermoplastic resin” or the like). In order to improve the low-temperature fixability of the toner, the core of the capsule toner particles preferably contains a thermoplastic resin (more specifically, the above-mentioned “preferable thermoplastic resin” or the like).

  Hereinafter, an embodiment in which the toner particles contained in the toner are non-capsule toner particles will be described. The toner base particles (binder resin and internal additive) and the external additive will be described in order.

[Toner mother particles]
The toner base particles contain a binder resin. The toner base particles may contain an internal additive (for example, a colorant, a release agent, a charge control agent, and a magnetic powder).

(Binder resin)
In the toner base particles, generally, the binder resin occupies most of the components (for example, 85% by mass or more). For this reason, it is considered that the properties of the binder resin greatly affect the properties of the entire toner base particles. By using a combination of a plurality of types of resins as the binder resin, the properties of the binder resin (more specifically, the hydroxyl value, acid value, Tg, Tm, etc.) can be adjusted. When the binder resin has an ester group, a hydroxyl group, an ether group, an acid group, or a methyl group, the toner base particles tend to be anionic, and when the binder resin has an amino group or an amide group. The toner base particles tend to be cationic.

  In order to improve the storage stability or durability of the toner while maintaining excellent low-temperature fixability of the toner, the glass transition point (Tg) of the binder resin contained in the toner base particles is 45 ° C. or higher and 65 ° C. or lower. It is preferable that In order to improve the storage stability or durability of the toner while maintaining excellent low-temperature fixability of the toner, the softening point (Tm) of the binder resin contained in the toner base particles is 80 ° C. or higher and 120 ° C. or lower. Preferably there is. Each measuring method of Tg and Tm is the same method as the Example mentioned later, or its alternative method.

  In order to improve the low-temperature fixability of the toner, it is preferable that the toner base particles contain a thermoplastic resin as the binder resin, and contain the thermoplastic resin in a proportion of 85% by mass or more of the entire binder resin. Is more preferable. As the thermoplastic resin contained in the toner base particles, the above-mentioned “suitable thermoplastic resin” is preferable, and a polyester resin or a styrene-acrylic acid resin is particularly preferable.

(Coloring agent)
The toner base particles may contain a colorant. As the colorant, a known pigment or dye can be used according to the color of the toner. In order to form a high-quality image using toner, the amount of the colorant is preferably 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the binder resin.

  The toner base particles may contain a black colorant. An example of a black colorant is carbon black. The black colorant may be a colorant that is toned to black using a yellow colorant, a magenta colorant, and a cyan colorant.

  The toner base particles may contain a color colorant such as a yellow colorant, a magenta colorant, or a cyan colorant.

  As the yellow colorant, for example, one or more compounds selected from the group consisting of condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and arylamide compounds can be used. Examples of the yellow colorant include C.I. I. Pigment Yellow (3, 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155 168, 174, 175, 176, 180, 181, 191, or 194), naphthol yellow S, Hansa yellow G, or C.I. I. Vat yellow can be preferably used.

  The magenta colorant is, for example, selected from the group consisting of condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. One or more compounds can be used. Examples of the magenta colorant include C.I. I. Pigment Red (2, 3, 5, 6, 7, 19, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 144, 146, 150, 166, 169, 177 184, 185, 202, 206, 220, 221 or 254) can be preferably used.

  As the cyan colorant, for example, one or more compounds selected from the group consisting of a copper phthalocyanine compound, an anthraquinone compound, and a basic dye lake compound can be used. Examples of cyan colorants include C.I. I. Pigment blue (1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, or 66), phthalocyanine blue, C.I. I. Bat Blue, or C.I. I. Acid blue can be preferably used.

(Release agent)
The toner base particles may contain a release agent. The release agent is used, for example, for the purpose of improving the fixing property or offset resistance of the toner. In order to improve the fixing property or offset resistance of the toner, the amount of the release agent is preferably 1 part by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the binder resin.

  Examples of the release agent include low molecular weight polyethylene, low molecular weight polypropylene, polyolefin copolymer, polyolefin wax, microcrystalline wax, paraffin wax, or aliphatic hydrocarbon wax such as Fischer-Tropsch wax; oxidized polyethylene wax or a block thereof Oxides of aliphatic hydrocarbon waxes such as copolymers; plant waxes such as candelilla wax, carnauba wax, wood wax, jojoba wax, or rice wax; animal properties such as beeswax, lanolin, or whale wax Waxes; mineral waxes such as ozokerite, ceresin, or petrolatum; waxes based on fatty acid esters such as montanate ester wax or castor wax; fats such as deoxidized carnauba wax The wax portion of the ester or the whole was deoxygenated can be suitably used. One type of release agent may be used alone, or multiple types of release agents may be used in combination.

  In order to improve the compatibility between the binder resin and the release agent, a compatibilizing agent may be added to the toner base particles.

(Charge control agent)
The toner base particles may contain a charge control agent. The charge control agent is used, for example, for the purpose of improving the charge stability or charge rising property of the toner. The charge rising characteristic of the toner is an index as to whether or not the toner can be charged to a predetermined charge level in a short time.

  By adding a negatively chargeable charge control agent to the toner base particles, the anionicity of the toner base particles can be enhanced. Further, by adding a positively chargeable charge control agent to the toner base particles, the cationic property of the toner base particles can be enhanced. However, if sufficient chargeability is ensured in the toner, it is not necessary to add a charge control agent to the toner base particles.

(Magnetic powder)
The toner base particles may contain magnetic powder. Examples of magnetic powder materials include ferromagnetic metals (more specifically, iron, cobalt, nickel, etc.) or alloys thereof, ferromagnetic metal oxides (more specifically, ferrite, magnetite, or chromium dioxide). Etc.) or a material subjected to a ferromagnetization treatment (more specifically, a heat treatment etc.) can be suitably used. One type of magnetic powder may be used alone, or a plurality of types of magnetic powder may be used in combination.

[External additive]
The toner particles contained in the toner according to the present embodiment include resin particles as an external additive. For example, when the toner base particles and the external additive are stirred together, the external additive adheres (physically bonds) to the surface of the toner base particles with a physical force. In order to improve the fluidity of the toner, the toner particles preferably further include one or more inorganic particles as an external additive in addition to the resin particles. As inorganic particles, particles of silica particles or metal oxides (more specifically, alumina, titanium oxide, magnesium oxide, zinc oxide, strontium titanate, barium titanate, etc.) can be suitably used. Multiple types of inorganic particles may be used in combination. In order to improve the fluidity of the toner, it is preferable to use silica particles as the inorganic particles. In order to improve the abrasiveness of the toner, it is preferable to use titanium oxide particles as inorganic particles. In order to improve the fluidity and abrasiveness of the toner, it is particularly preferable that the toner particles further include silica particles and titanium oxide particles as external additives in addition to the resin particles. In order to improve the fluidity or handleability of the toner, the amount of the external additive (when a plurality of types of external additives are used, the total amount of these external additives) is 100 parts by mass of the toner base particles. On the other hand, it is preferable that they are 0.5 mass part or more and 10 mass parts or less.

[Toner Production Method]
Hereinafter, an example of a method for producing the toner according to the exemplary embodiment will be described.

(Preparation of toner mother particles)
Preferable examples of the method for producing the toner base particles include a pulverization method or an aggregation method. These methods facilitate easy dispersion of the internal additive in the binder resin.

  In an example of the pulverization method, first, a binder resin, a colorant, a charge control agent, and a release agent are mixed. Subsequently, the obtained mixture is melt-kneaded using a melt-kneading apparatus (for example, a single-screw or twin-screw extruder). Subsequently, the obtained melt-kneaded product is pulverized and classified. Thereby, toner mother particles are obtained. When the pulverization method is used, the toner base particles can often be produced more easily than when the aggregation method is used.

  In an example of the aggregation method, first, these fine particles are aggregated in an aqueous medium containing fine particles of the binder resin, the release agent, and the colorant until a desired particle diameter is obtained. Thereby, aggregated particles containing a binder resin, a release agent, and a colorant are formed. Subsequently, the obtained aggregated particles are heated to unite the components contained in the aggregated particles. Thereby, toner mother particles having a desired particle diameter are obtained.

(Washing process)
The obtained toner base particles may be washed. As a method for cleaning the toner base particles, for example, the dispersion containing the toner base particles is solid-liquid separated to collect the wet cake-like toner base particles, and the collected wet cake-like toner base particles are washed with water. Is preferred. As a method for cleaning the toner base particles, a method is preferred in which the toner base particles in the dispersion containing the toner base particles are settled, the supernatant liquid is replaced with water, and the toner base particles are redispersed in water after the replacement.

(Drying process)
After the cleaning step, the toner base particles may be dried. For example, the toner base particles can be dried using a dryer (more specifically, a spray dryer, a fluidized bed dryer, a vacuum freeze dryer, a vacuum dryer, or the like). In order to suppress aggregation of the toner base particles during drying, it is preferable to dry the toner base particles using a spray dryer. In the case of using a spray dryer, for example, by spraying a dispersion liquid in which an external additive is dispersed onto the toner base particles, the drying step and the external addition step described later can be performed simultaneously.

(Preparation of resin particles)
The resin particles can be obtained, for example, by emulsion polymerization of an unsaturated monomer in an aqueous medium and drying the obtained emulsion. The aqueous medium is a medium containing water as a main component (more specifically, pure water or a mixed liquid of water and a polar medium). In producing the resin particles, it is preferable to use pure water (for example, ion-exchanged water) to which an additive (for example, a surfactant) is added as the aqueous medium. The aqueous medium may function as a solvent. A solute may be dissolved in the aqueous medium. The aqueous medium may function as a dispersion medium. The dispersoid may be dispersed in the aqueous medium. As a polar medium in the aqueous medium, for example, alcohol (more specifically, methanol or ethanol) can be used. A surfactant and / or protective colloid may be dissolved or dispersed in the aqueous medium. As the surfactant, a reactive surfactant may be used, or a non-reactive surfactant may be used. Surfactants may be used as emulsifiers. Preferable examples of the surfactant having reactivity include a propenyl group-containing surfactant having radical polymerization properties (more specifically, an anionic surfactant or a nonionic surfactant). As the protective colloid, a water-soluble polymer (more specifically, polyvinyl alcohol or the like) can be preferably used. Two or more surfactants and protective colloids may be used.

  Preferable examples of the unsaturated monomer used for the production of the resin particles include ethylene, propylene, vinyl acetate, vinyl propionate, acrylonitrile, methacrylonitrile, (meth) acrylic acid alkyl ester (more specifically, ( (Meth) methyl acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, or 2-ethylhexyl (meth) acrylate), styrenic monomers (more specifically Examples thereof include styrene, α-methylstyrene, tert-butylstyrene, vinyltoluene, and the like, or (meth) acrylic acid esters of alkylene glycol (more specifically, ethylene glycol dimethacrylate and the like). Two or more unsaturated monomers may be used.

(External addition process)
An external additive (for example, resin particles and / or inorganic particles) is attached to the surface of the toner base particles obtained as described above. For example, by using a mixer having a stirring blade (for example, FM mixer manufactured by Nihon Coke Kogyo Co., Ltd.), the toner base particles and the resin particles are mixed, whereby the surface layer portion of the toner base particles has the relationship of Formula 1. A rising portion that satisfies all of the relationship of Equation 2 and the relationship of Equation 3 (respectively defined by the above-described basic configuration) can be formed. In order to produce the toner having the above-described basic configuration, toner mother particles containing a resin having a glass transition point of 45 ° C. or more and 60 ° C. or less at least in the surface layer portion are prepared, and 5 ° C. higher than the glass transition point of the resin. It is preferable to mix the toner base particles and the resin particles at a temperature lower than the above and not lower than 30 ° C. (for example, a temperature not lower than 30 ° C. and not higher than 50 ° C.). By appropriately heating the toner base particles and the resin particles, the resin becomes easily compatible. However, if the temperature during mixing (specifically, the temperature in the mixer) is too high, the toner base particles tend to aggregate. When inorganic particles are used as the external additive in addition to the resin particles, the toner is preferably produced by a method including the first mixing and the second mixing as described below. In the first mixing, toner base particles, resin particles, and 1% by mass to 50% by mass of first inorganic particles are mixed with respect to the resin particles. For example, if the amount of the resin particles is 100 g, the amount of the first inorganic particles is 1 g or more and 50 g or less. In the second mixing, the mixture mixed by the first mixing and the second inorganic particles of 50% by mass or more and 150% by mass or less with respect to the resin particles are further mixed. For example, if the amount of the resin particles is 100 g, the amount of the second inorganic particles is 50 g or more and 150 g or less. The first inorganic particles and the second inorganic particles may be the same type of particles or different types of particles. However, in order to improve the fluidity of the toner, the first inorganic particles and the second inorganic particles are preferably silica particles.

  Through the above process, a toner containing a large number of toner particles can be produced. Note that unnecessary steps may be omitted. For example, when a commercially available product can be used as a material as it is, the step of preparing the material can be omitted by using a commercially available product. In order to produce the toner efficiently, it is preferable to produce a large number of toner particles simultaneously. The toner particles produced at the same time are considered to have substantially the same configuration.

Examples of the present invention will be described. Table 1 shows toners TA-1 to TA-10, TB-1, TB-2, and TC (each toner for developing an electrostatic latent image) according to Examples or Comparative Examples. In addition, the unit of SP value described in Table 1 is (cal / cm ³ ) ^1/2 .

  Hereinafter, a manufacturing method, an evaluation method, and an evaluation result of toners TA-1 to TA-10, TB-1, TB-2, and TC will be described in order. In the evaluation in which an error occurs, a considerable number of measurement values with sufficiently small errors are obtained, and the arithmetic average of the obtained measurement values is used as the evaluation value. Moreover, the measuring methods of Tg (glass transition point) and Tm (softening point) are as follows unless otherwise specified.

<Measurement method of Tg>
Using a differential scanning calorimeter (“DSC-6220” manufactured by Seiko Instruments Inc.), the endothermic curve (vertical axis: heat flow (DSC signal), horizontal axis: temperature) of the sample (for example, resin) was determined. Subsequently, the Tg (glass transition point) of the sample was read from the obtained endothermic curve. The temperature of the specific heat change point (intersection of the extrapolation line of the base line and the extrapolation line of the falling line) in the obtained endothermic curve corresponds to the Tg (glass transition point) of the sample.

<Tm measurement method>
A sample (for example, resin) is set on a Koka type flow tester (“CFT-500D” manufactured by Shimadzu Corporation), a die pore diameter of 1 mm, a plunger load of 20 kg / cm ² , and a temperature rising rate of 6 ° C./min. Then, a 1 cm ³ sample was melted and discharged, and an S-shaped curve (horizontal axis: temperature, vertical axis: stroke) of the sample was obtained. Subsequently, the Tm (softening point) of the sample was read from the obtained S-shaped curve. In the obtained S-curve, if the maximum stroke value is S ₁ and the low-temperature baseline stroke value is S ₂ , the stroke value in the S-curve is “(S ₁ + S ₂ ) / 2”. Corresponds to the Tm (softening point) of the sample.

[Preparation of materials]
(Preparation of resin dispersion A)
Number average molecular weight (Mn) 3900, mass average molecular weight (Mw) 11700, Mw / Mn (molecular weight distribution) 3.0, Tm (softening point) 102 ° C., Tg (glass transition point) 54 ° C., SP value 9.6 Acrylic acid resin was prepared. 1000 g of the prepared acrylic resin is put into a container of a mixing device (“TK Hibis Disper Mix HM-3D-5” manufactured by Primics Co., Ltd.) equipped with a temperature control jacket, and the temperature is 120 ° C. The container contents were melt-kneaded under the following conditions. Subsequently, 80 g of triethanolamine, 20 g of an anionic surfactant (“Emar (registered trademark) 0” manufactured by Kao Corporation, component: sodium lauryl sulfate) and 60 g of ion-exchanged water were added to the container, The contents of the container were mixed for 15 minutes at a Lee rotation speed of 50 rpm. Subsequently, 2870 g of ion-exchanged water having a temperature of 98 ° C. was charged into the container at a rate of 50 g / min to obtain a resin dispersion A having a solid content concentration of 25 mass% containing acrylic resin particles. The number average particle diameter of the resin particles contained in the obtained resin dispersion A was 105 nm.

(Preparation of resin dispersion B)
The resin dispersion B was prepared by a number average molecular weight (Mn) of 2800, a mass average molecular weight (Mw) of 7000, a Mw / Mn (molecular weight distribution) of 2.5, and a Tm (softening point) of 94 instead of the acrylic resin. It was the same as the preparation method of Resin Dispersion A except that a polyester resin having a Tg (glass transition point) of 53 ° C, an acid value of 13.6 mgKOH / g, and an SP value of 9.8 was prepared and used. Regarding the resin particles contained in the obtained resin dispersion B, the solid content concentration was 25% by mass, and the number average particle size was 95 nm.

(Preparation of resin dispersion C)
The resin dispersion C was prepared by a number average molecular weight (Mn) 3600, a mass average molecular weight (Mw) 9100, a Mw / Mn (molecular weight distribution) 2.5, and a Tm (softening point) 93 instead of the acrylic resin. It was the same as the preparation method of Resin Dispersion A, except that a styrene-acrylic acid resin having a C, Tg (glass transition point) of 52 ° C. and an SP value of 9.2 was prepared and used. With respect to the resin particles contained in the obtained resin dispersion C, the solid content concentration was 25% by mass and the number average particle size was 92 nm.

(Preparation of release agent dispersion)
200 g of ester wax (“Nissan Electol (registered trademark) WEP-3” manufactured by NOF Corporation, melting temperature: 73 ° C.) and an anionic surfactant (“Emar 0” manufactured by Kao Corporation, component: sodium lauryl sulfate) 1 g and 800 g of ion-exchanged water were mixed. Subsequently, the obtained mixed solution was heated to 100 ° C. to melt the wax in the mixed solution. Subsequently, the liquid containing the wax was emulsified for 5 minutes using a homogenizer (“Ultra Tarrax T50” manufactured by IKA), and then a gorin type homogenizer (“APV homogenizer 15M-8TA manufactured by SPX). Type | mold)), the emulsification process was performed at the temperature of 70 degreeC, and the dispersion liquid (release agent dispersion liquid) of the release agent particle | grains was obtained. With respect to the obtained release agent dispersion, the solid content concentration was 20% by mass, and the volume average particle size (MV) was 0.15 μm.

(Preparation of colorant dispersion)
20 g of an anionic surfactant (“Emar 0” manufactured by Kao Corporation, component: sodium lauryl sulfate) was dissolved in 410 g of ion exchange water to obtain an aqueous solution of a surfactant. Subsequently, 70 g of a cyan colorant (“CTBX121” manufactured by DIC Corporation, component: copper phthalocyanine) was gradually added to the obtained aqueous solution. After completion of the addition, the liquid containing the colorant was subjected to an emulsification treatment for 5 minutes using a homogenizer (“Ultra Tarrax T50” manufactured by IKA), and then a gorin type homogenizer (“APV homogenizer 15M manufactured by SPX). -8TA type ") was emulsified at a temperature of 100 ° C to obtain a dispersion of colorant particles. With respect to the obtained dispersion of colorant particles, the solid content concentration was 14% by mass, and the volume average particle size (MV) was 0.19 μm.

(Preparation of resin particles A for external additives)
In a 500 mL flask equipped with a dropping funnel, a stirrer, a nitrogen gas inlet tube, a thermometer, and a reflux condenser, 200 g of ion-exchanged water and 3 g of sodium lauryl sulfate were placed. Subsequently, while stirring the flask contents in a nitrogen atmosphere, the temperature of the flask contents was raised to 80 ° C., and 1 g of ammonium persulfate was added to the flask during the temperature increase. Subsequently, a mixture of 30 g of methyl methacrylate, 30 g of n-butyl acrylate, and 40 g of ethylene glycol dimethacrylate was dropped into the flask over 1 hour. After completion of dropping, the flask contents were further stirred for 1 hour. Subsequently, the flask contents were cooled to room temperature (about 25 ° C.) and then sieved using a 300-mesh sieve to obtain an emulsion of resin particles A. Subsequently, the obtained emulsion was dried to obtain resin particles A (powder).

(Preparation of resin particles B for external additives)
The production method of the resin particles B (powder) was the same as the production method of the resin particles A except that the amount of sodium lauryl sulfate added was changed from 3 g to 1 g.

(Preparation of resin particles C for external additives)
The production method of the resin particles C (powder) was the same as the production method of the resin particles A except that the amount of sodium lauryl sulfate added was changed from 3 g to 6 g.

(Preparation of resin particles D for external additives)
The production method of the resin particle D (powder) is a production method of the resin particle A except that the addition amount of methyl methacrylate is changed from 30 g to 20 g and the addition amount of n-butyl acrylate is changed from 30 g to 40 g. Was the same.

(Preparation of resin particles E for external additives)
Resin particles E (powder) were prepared by using a mixture of 30 g of methyl methacrylate, 30 g of n-butyl acrylate, and 40 g of ethylene glycol dimethacrylate, 40 g of methyl methacrylate, 30 g of n-butyl acrylate, and di Except that a mixture of 10 g of ethylene glycol methacrylate and 20 g of styrene was used, it was the same as the production method of the resin particle A.

(Preparation of resin particles F for external additives)
The production method of the resin particles F (powder) was the same as the production method of the resin particles A except that the addition amount of sodium lauryl sulfate was changed from 3 g to 12 g.

(Preparation of resin particles G for external additives)
The production method of the resin particles G (powder) was the same as the production method of the resin particles A except that the addition amount of sodium lauryl sulfate was changed from 3 g to 0.6 g.

(Preparation of resin particles H for external additives)
The resin particle H (powder) was prepared by using a mixture of 50 g of methyl methacrylate and 50 g of styrene instead of a mixture of 30 g of methyl methacrylate, 30 g of n-butyl acrylate, and 40 g of ethylene glycol dimethacrylate. Except for this, it was the same as the method for preparing the resin particles A. The Tm (softening point) of the resin particle H was 145 ° C. In addition, regarding resin particles A to G, I, and J, a clear Tm (softening point) could not be measured by the measurement method described above.

(Preparation of resin particles I for external additives)
The resin particle I (powder) was prepared by using 50 g of methyl methacrylate, 20 g of styrene and 30 g of divinylbenzene instead of a mixture of 30 g of methyl methacrylate, 30 g of n-butyl acrylate and 40 g of ethylene glycol dimethacrylate. Except that the mixture was used, it was the same as the production method of the resin particle A.

(Preparation of resin particles J for external additives)
The resin particle J (powder) was prepared by changing the amount of sodium lauryl sulfate from 3 g to 6 g, instead of a mixture of 30 g of methyl methacrylate, 30 g of n-butyl acrylate, and 40 g of ethylene glycol dimethacrylate. This was the same as the method for preparing the resin particles A except that a mixture of 50 g of methyl methacrylate and 50 g of isobornyl methacrylate was used.

(Preparation of silica particles for external additives)
30 g of dimethylpolysiloxane (manufactured by Shin-Etsu Chemical Co., Ltd.) and 15 g of 3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.) were dissolved in 200 g of toluene to obtain a solution. Subsequently, the resulting solution was diluted 10 times. Subsequently, while the obtained diluted solution is gradually added dropwise to 200 g of silica particles (“AEROSIL (registered trademark) 130, manufactured by Nippon Aerosil Co., Ltd., hydrophilic fumed silica)”, the silica particles are stirred to obtain a mixture. Obtained. Furthermore, the mixture was subjected to ultrasonic irradiation for 30 minutes while stirring the mixture.

  Subsequently, the ultrasonically irradiated mixture was heated to 150 ° C. using a thermostatic bath. Subsequently, toluene was distilled off from the mixture using a rotary evaporator. As a result, a solid was obtained.

  Subsequently, the obtained solid was dried using a vacuum dryer at a set temperature of 50 ° C. until the weight was not reduced. Subsequently, the dried solid was heated for 3 hours using an electric furnace in a nitrogen stream at a set temperature of 200 ° C. Subsequently, the heated solid was pulverized using a jet mill and collected with a bag filter to obtain silica particles (powder).

[Production of Toners TA-1 to TA-10, TB-1, TB-2, and TC]
(Preparation of toner base particles)
Toner material prepared in the above procedure (specifically, 320 g of resin dispersion, 90 g of release agent dispersion, and 40 g of colorant dispersion) and an anionic surfactant (“Emar 0” manufactured by Kao Corporation, component: lauryl 50 g of 25% strength by weight aqueous solution of sodium sulfate and 500 g of distilled water were put into a 2 L stainless round bottom flask. The resin dispersion (toner material) is defined in each of toners TA-1 to TA-10, TB-1, TB-2, and TC. It was one of the resin dispersions A to C shown in “Type”).

  Subsequently, 1 g of 1N sodium hydroxide aqueous solution was added to the flask while stirring the flask contents, and the pH of the flask contents was adjusted to 8. Subsequently, the flask contents were stirred for 10 minutes under the conditions of a temperature of 25 ° C. and a rotation speed of 100 rpm.

Further, 39 g of magnesium chloride hexahydrate (flocculating agent) aqueous solution having a solid content concentration of 50% by mass was dropped into the flask over 5 minutes while stirring the contents of the flask. Subsequently, the contents of the flask were heated at a rate of 0.2 ° C./min to promote particle aggregation in the flask and granulate. The temperature increase was continued until the median diameter (D _n50 ) of the aggregated particles reached 4.5 μm. Specifically, the temperature increase was stopped at about 46 ° C.

  Subsequently, the rotation speed of stirring was increased from 100 rpm to 200 rpm, and the temperature was raised to 55 ° C. at a speed of 0.2 ° C./min while stirring the contents of the flask. Then, the contents of the flask were stirred at a temperature of 55 ° C. for 60 minutes to coalesce the aggregated particles in the flask. As a result, a dispersion of toner base particles having a circularity of 0.953 was obtained.

(Washing)
The dispersion of toner base particles obtained as described above was filtered (solid-liquid separation) using a Buchner funnel. As a result, toner base particles in the form of wet cake were obtained. Thereafter, the obtained wet cake-like toner base particles were redispersed in ion-exchanged water. Further, dispersion and filtration were repeated 5 times to wash the toner base particles.

(Dry)
Subsequently, the washed wet cake-like toner base particles were dried at a temperature of 35 ° C. for 48 hours. As a result, toner mother particles having a volume median diameter (D _v50 ) of 5.53 μm and a circularity of 0.959 were obtained.

(External)
After the drying, external addition was performed on the toner base particles. Specifically, using a 10 L capacity FM mixer (manufactured by Nihon Coke Kogyo Co., Ltd.) having a temperature control jacket (for example, a hot water jacket), 1000 g of toner base particles are circulated while circulating hot water at a predetermined temperature through the jacket. 2 g of the silica particles prepared by the above procedure and 15 g of the resin particles prepared by the above procedure were mixed for 3 minutes. The resin particles (external additives) are defined in each of the toners TA-1 to TA-10, TB-1, TB-2, and TC. ]) Any of the resin particles A to J. The temperature of the hot water flowing through the jacket was 45 ° C. in the production of the toner TC and 30 ° C. in the production of other toners as shown in “External addition temperature” in Table 1.

  Subsequently, 13 g of silica particles prepared by the above procedure were further added to the obtained mixture, and the toner base particles, resin particles, and silica particles were further mixed for 10 minutes using the FM mixer. As a result, external additives (silica particles and resin particles) adhered to the surface of the toner base particles, and a powder containing a large number of toner particles was obtained. Thereafter, the obtained powder was sieved using a 300 mesh (aperture 48 μm) sieve. As a result, toners (toners TA-1 to TA-10, TB-1, TB-2, and TC) containing a large number of toner particles were obtained.

[Shape of raised part]
For each sample (toners TA-1 to TC) obtained as described above, the diameter D1 of the resin particles, the diameter D2 of the peripheral region, and the rising height difference ΔH (= maximum height H2−) are obtained by the following method. The rising height H0) was measured. As a measuring apparatus, an SPM probe station (“NanoNaviReal” manufactured by Hitachi High-Tech Science Co., Ltd.) equipped with a scanning probe microscope (SPM) (“Multifunctional unit AFM5200S” manufactured by Hitachi High-Tech Science Co., Ltd.) was used. Prior to the measurement, an average toner particle is selected from the toner particles contained in the sample (toner) using a scanning electron microscope (SEM) (“JSM-6700F” manufactured by JEOL Ltd.). Toner particles were measured. Further, the toner particles were set on the measurement table of the measurement apparatus (SPM) without being cut. Then, the field of view (measurement site) was set so that the region where the resin particles existed on the surface of the toner particles was included in the measurement range.

(SPM measurement conditions)
Measurement probe: low spring constant silicon cantilever ("OMCL-AC240TS-C3" manufactured by Olympus Corporation, spring constant: 2 N / m, resonance frequency: 70 kHz, back reflection coating material: aluminum)
・ Measurement mode: DFM (dynamic force mode)
・ Measurement range (one field of view): 1μm × 1μm
・ Resolution (X data / Y data): 256/256
・ Q gain: 1 × ・ Scanning frequency: 1 Hz

  With the measurement mode (DFM), the toner particles are controlled while controlling the distance between the probe and the toner particles so that the amplitude of the vibrating cantilever becomes constant while the cantilever (tip portion: probe) is resonated. A shape image (image showing the surface shape) was obtained. The toner particles were moved with the position of the cantilever fixed. The resulting shape image is analyzed using image analysis software (“WinROOF” manufactured by Mitani Corporation) and GIMP (GNU Image Manipulation Program: image editing / processing software distributed under the GNU General Public License). Then, a cross-sectional shape (for example, see FIG. 4) of the toner particles (particularly, the raised portion) was obtained. Shape characteristic values (D1, 2 × D1, D2, and ΔH / D1) were determined from the obtained toner particle shape image and cross-sectional shape. While changing the field of view, the shape characteristic value was measured for each of the 10 raised portions included in one toner particle. Then, the arithmetic average of the obtained shape characteristic values at 10 locations was used as the shape characteristic value of one toner particle as a measurement target. The shape characteristic value was measured for each of 10 toner particles contained in the sample (toner). The number average value of 10 toner particles was used as the evaluation value (D1, 2 × D1, D2, and ΔH / D1) of the sample (toner).

[Change rate of BET specific surface area]
The change rate of the BET specific surface area of the toner particles before and after the heat resistance storage test was measured. In the heat resistance storage test, the sample (toner) was allowed to stand for 3 hours in an environment of a temperature of 80 ° C. and a humidity of 20% RH. Before and after such a heat-resistant storage test, the BET specific surface area of the toner particles contained in the sample was measured using a BET specific surface area measuring device (Mounttech "HM MODEL-1208"). From the BET specific surface area S _A of the toner particles contained in the sample before the heat-resistant storage test and the BET specific surface area S _{B of the} toner particles contained in the sample after the heat-resistant storage test, the formula “Change rate of BET specific surface area = S _B The change rate of the BET specific surface area represented by “/ S _A ” was determined.

[Evaluation method]
The evaluation method of each sample (toners TA-1 to TA-10, TB-1, TB-2, and TC) is as follows.

(Heat resistant storage stability)
3 g of a sample (toner) was put in a 20 mL polyethylene container, and the container was left in a thermostat set at 60 ° C. for 3 hours. Thereafter, the toner taken out from the thermostatic chamber was allowed to stand for 30 minutes in an environment of a temperature of 25 ° C. and a humidity of 65% RH, thereby obtaining an evaluation toner.

Subsequently, the obtained toner for evaluation was placed on a sieve having a known opening of 45 μm. Then, the mass of the sieve containing the evaluation toner was measured, and the mass of the toner before sieving was determined. Subsequently, the sieve was set in a powder tester (manufactured by Hosokawa Micron Corporation), and the sieve for evaluation was sieved by vibrating the sieve for 30 seconds under the conditions of the rheostat scale 5 according to the manual of the powder tester. Then, after sieving, the mass of the sieve containing toner was measured to determine the mass of the toner remaining on the sieve (toner that did not pass through the sieve). From the mass of the toner before sieving and the mass of the toner after sieving (the mass of the toner remaining on the sieving after sieving), the aggregation rate (unit: mass%) was determined based on the following formula.
Aggregation rate = 100 × mass of toner after sieving / mass of toner before sieving

  When the aggregation rate was 20% by mass or less, it was evaluated as “good”, and when the aggregation rate was more than 20% by mass, it was evaluated as “poor” (not good).

(Production of evaluation carrier)
2 L of water was added to 30 g of polyamideimide resin to prepare a resin solution. Subsequently, 120 g of tetrafluoroethylene-6 fluoropropylene copolymer (FEP) and 3 g of silicon oxide were dispersed in the obtained resin solution to obtain a carrier coat solution. Subsequently, 10 kg of a non-coated ferrite core (“EF-35B” manufactured by Powder Tech Co., Ltd., particle size: 35 μm) was coated with the carrier coating solution using a fluidized bed coating apparatus. Thereafter, the ferrite particles coated with the resin were fired at 250 ° C. for 1 hour. As a result, an evaluation carrier was obtained.

(Preparation of developer for evaluation)
30 g of a sample (toner) and 300 g of the evaluation carrier prepared as described above were put in a polyethylene container having a capacity of 500 mL, and shaker mixer ("Turbler (registered by Willy et Bacofen (WAB))" was registered. (Trademark) mixer T2F ") for 30 minutes to prepare a developer for evaluation (two-component developer).

(Preparation of evaluation machine)
A color multifunction machine (“TASKalfa 5500ci” manufactured by Kyocera Document Solutions Inc.) was used as an evaluation machine. The evaluation developer prepared as described above was charged into the developing device of the evaluation machine, and the sample (replenishment toner) was charged into the toner container of the evaluation machine.

(Adhesion resistance)
Using the evaluation machine, a line pattern (bar graph pattern in which the longitudinal direction of the bars coincides with the paper transport direction) was printed on 10000 sheets of paper (each A4 in an environment of temperature 25 ° C. and humidity 65% RH). A printing durability test for continuous printing on plain paper (size) was conducted. After the printing durability test, the surface of each of the developing sleeve and the photosensitive drum of the evaluation machine and the image formed by the printing durability test were visually observed to check for toner adhesion. When the toner does not adhere to either the developing sleeve or the photosensitive drum, it is evaluated as “good”, and when the toner adheres to either the developing sleeve or the photosensitive drum, × (not good). evaluated.

(Image density)
Using the evaluation machine, a printing durability test was performed in which a character pattern having a printing rate of 2% was continuously printed on 10,000 sheets of paper (each A4 size plain paper) in an environment of a temperature of 25 ° C. and a humidity of 65% RH. After the printing durability test, a sample image including the solid portion was printed on an evaluation sheet, and the image density (ID) of the solid portion in the sample image was measured. For the measurement of image density, a reflection densitometer (“SpectroEye (registered trademark)” manufactured by X-Rite) was used. When the image density was 1.30 or more, it was evaluated as “good”, and when the image density was less than 1.30, “× (not good)” was evaluated.

(Minimum fixing temperature)
Using the evaluation machine, an unfixed solid image was formed on an evaluation paper having a basis weight of 90 g / m ² (“C ² ” manufactured by Fuji Xerox Co., Ltd.) under the condition of a toner loading amount of 0.4 mg / cm ² . . Then, the fixability of the sample (toner) was evaluated using the formed image.

  Specifically, the paper on which the image was formed as described above was passed through the fixing device of the evaluation machine under the condition of a linear speed of 266 mm / second. Subsequently, the presence or absence of toner fixing was confirmed. By such a test, the lowest temperature (minimum fixing temperature) at which the toner can be fixed on the paper in the fixing temperature range of 100 ° C. to 200 ° C. was measured. The fixing temperature of the fixing device was increased by 5 ° C. from 100 ° C. Whether or not the fixing was possible was confirmed by a rub test (measurement of crease peeling length). Specifically, the evaluation paper passed through the fixing device was bent so that the surface on which the image was formed was on the inside, and the image on the fold was rubbed 5 times with a 1 kg weight coated with a cloth. Subsequently, the paper was spread and the bent portion of the paper (the portion where the solid image was formed) was observed. Then, the length (peeling length) of toner peeling at the bent portion was measured. The lowest temperature among the fixing temperatures at which the peeling length was 1 mm or less was defined as the lowest fixing temperature. When the minimum fixing temperature was 150 ° C. or lower, it was evaluated as “good”, and when the minimum fixing temperature exceeded 150 ° C., it was evaluated as “poor” (not good).

[Evaluation results]
Table 2 summarizes the evaluation results of each sample (toners TA-1 to TA-10, TB-1, TB-2, and TC).

The toners TA-1 to TA-5, TB-1, and TC (the toners according to Examples 1 to 7) each had the above-described basic configuration. Specifically, in the peripheral region of the resin particles adhering to the surface of the toner base particles, the surface layer portion of the toner base particles rises toward the resin particles. As shown in Table 1, in each of the toners according to Examples 1 to 7, the diameter D1 of the resin particles and the diameter D2 of the peripheral region (the peripheral region of the resin particle where the surface layer portion of the toner base particles is raised) are obtained. And the rising height difference ΔH (the height difference between the rising start height H0 and the maximum height H2) satisfies all of the following relationships of Equation 1, Equation 2, and Equation 3. It was.
Formula 1: 50 nm ≦ D1 ≦ 150 nm
Formula 2: (2 × D1) ≦ D2
Formula 3: 1.00 <(ΔH / D1) ≦ 1.50

  As shown in Table 2, the toners according to Examples 1 to 7 were excellent in low-temperature fixability and heat-resistant storage stability. In addition, when the toners according to Examples 1 to 7 are used for continuous printing, high-quality images are suppressed while suppressing toner fixation (toner adhesion to the developing sleeve and toner adhesion to the photosensitive drum). Could continue to form.

  The toner for developing an electrostatic latent image according to the present invention can be used to form an image in, for example, a copying machine, a printer, or a multifunction machine.

10 Toner Particles 11 Toner Base Particles 12 Resin Particles P11 Lifting Start Part P12 Lifting Finishing Part P21 Bottom Part P22 Top Part R11 Non-Rising Part R12 Lifting Part

Claims (8)

An electrostatic latent image developing toner comprising a plurality of toner particles comprising toner base particles containing a binder resin and spherical resin particles attached to the surface of the toner base particles,
In the peripheral region of the resin particles, the surface layer portion of the toner base particles rises toward the resin particles,
The diameter D1 of the resin particle, the diameter D2 of the peripheral region of the resin particle where the surface layer portion of the toner base particle is rising, the rising start height of the surface layer portion of the toner base particle, and the maximum of the resin particle The difference in height ΔH from the height is a toner for developing an electrostatic latent image that satisfies all of the relationship of the formula 1, the relationship of the formula 2, and the relationship of the formula 3.
Formula 1: 50 nm ≦ D1 ≦ 150 nm
Formula 2: (2 × D1) ≦ D2
Formula 3: 1.00 <(ΔH / D1) ≦ 1.50   The electrostatic latent image developing toner according to claim 1, wherein a change rate of a BET specific surface area of the toner particles is less than 1.0% before and after the toner is allowed to stand at a temperature of 80 ° C. for 3 hours. The electrostatic property according to claim 1 or 2, wherein a difference between an SP value of the binder resin and an SP value of the resin constituting the resin particles is 0.2 (cal / cm ³ ) ^1/2 or less. Latent image developing toner.   The toner for developing an electrostatic latent image according to claim 1, wherein the toner particles further include inorganic particles as external additives. A method for producing a toner for developing an electrostatic latent image according to any one of claims 1 to 4,
Preparing the toner base particles and the resin particles;
By mixing the toner base particles and the resin particles using a mixer equipped with a stirring blade, the relationship of the formula 1, the relationship of the formula 2, and the formula 3 is applied to the surface layer portion of the toner base particles. Forming a raised part that satisfies all of the relationships;
A method for producing a toner for developing an electrostatic latent image, comprising: In the preparation of the toner base particles, toner base particles containing a resin having a glass transition point of 45 ° C. or higher and 60 ° C. or lower at least on the surface layer portion are prepared,
The electrostatic latent image development according to claim 5, wherein the mixing by the mixer is performed at a temperature that is 5 ° C. or more lower than the glass transition point of the resin and not lower than 30 ° C. or less. Of manufacturing toner.   The method for producing a toner for developing an electrostatic latent image according to claim 5, wherein the mixing by the mixer is performed at a temperature of 30 ° C. or more and 50 ° C. or less. The mixing by the mixer is
A first mixture in which the toner base particles, the resin particles, and 1% by mass to 50% by mass of first inorganic particles are mixed with the resin particles;
A second mixture for further mixing the mixture mixed by the first mixing and the second inorganic particles of 50% by mass or more and 150% by mass or less with respect to the resin particles;
The manufacturing method of the toner for electrostatic latent image development as described in any one of Claims 5-7 containing these.

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