JP6447485B2 - Toner for electrostatic latent image development - Google Patents

Description

  The present invention relates to an electrostatic latent image developing toner.

  Patent Document 1 describes a toner in which carbon atoms (A) and sulfur atoms (E) exist on the surface of toner particles. The ratio (E / A) between the content of carbon atoms (A) and the content of sulfur atoms (E) is 0.0003 or more and 0.0050 or less. In the toner described in Patent Document 1, the toner particles contain at least a sulfonic acid polymer, a colorant, a binder resin, and a crystalline polyester.

JP 2006-78982 A

  However, it is difficult to provide a toner for developing an electrostatic latent image that is excellent in developability and storage stability only by the technique described in Patent Document 1.

  The present invention has been made in view of the above problems, and an object thereof is to provide a toner for developing an electrostatic latent image that is excellent in developability and storage stability.

  The electrostatic latent image developing toner of the present invention has a plurality of toner particles. The toner particles contain a quaternary ammonium salt. The quaternary ammonium salt has a hydrophobic group and a quaternary ammonium group as a hydrophilic group. The ratio of the quaternary ammonium salt in the surface layer of the toner particles is 10 ppm or more and 200 ppm or less as measured by time-of-flight secondary ion mass spectrometry (TOF-SIMS: Time of Flight Secondary Ion Mass Spectrometry). The ratio of the quaternary ammonium salt in the whole toner particles is 5 ppm or more and 120 ppm or less as measured by gas chromatography mass spectrometry (GCMS).

  According to the present invention, it is possible to provide an electrostatic latent image developing toner excellent in developability and storage stability.

  Hereinafter, embodiments of the present invention will be described in detail. The present invention is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the object of the present invention. In addition, about the location where description overlaps, although description may be abbreviate | omitted suitably, the summary of invention is not limited.

  The toner according to this embodiment is an electrostatic latent image developing toner. The toner according to this embodiment is a powder composed of a large number of toner particles. The toner according to the exemplary embodiment can be used in, for example, an electrophotographic apparatus (image forming apparatus).

  In an electrophotographic apparatus, an electrostatic latent image is developed using a developer containing toner. In the developing step, charged toner is attached to the electrostatic latent image formed on the photoconductor to form a toner image on the photoconductor. In the subsequent transfer process, the toner image on the photosensitive member is transferred to an intermediate transfer member (for example, an intermediate 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 this embodiment has the following configuration (1).
Configuration (1): The toner particles contain a quaternary ammonium salt. The quaternary ammonium salt has a hydrophobic group and a quaternary ammonium group as a hydrophilic group. The proportion of the quaternary ammonium salt in the surface layer of the toner particles (hereinafter sometimes referred to as “ratio A”) is 10 ppm or more and 200 ppm or less as measured by time-of-flight secondary ion mass spectrometry (TOF-SIMS). is there. The proportion of the quaternary ammonium salt in the entire toner particles (hereinafter sometimes referred to as “ratio B”) is 5 ppm or more and 120 ppm or less as measured by gas chromatography mass spectrometry (GCMS).

  The quaternary ammonium salt has a hydrophobic group and a quaternary ammonium group as a hydrophilic group. That is, the quaternary ammonium salt has a function as a surfactant. The ratio A is a ratio of the mass of the quaternary ammonium salt to the mass of the surface layer of the toner particles. The ratio A is measured using a time-of-flight secondary ion mass spectrometer (for example, “IV type” manufactured by ION-TOF (Germany)). The ratio B is the ratio of the mass of the quaternary ammonium salt to the total mass of the toner particles.

  The ratio B of 1 ppm means, for example, that the total mass of quaternary ammonium salts contained per 1 g of toner is 1 μg. The ratio B is measured using a gas chromatograph mass spectrometer. As the gas chromatograph mass spectrometer, for example, a pyrolysis gas chromatograph mass spectrometer (GCMS) (“GCMS-QP2010Ultra” manufactured by Shimadzu Corporation) and a pyrolyzer (“EGA / PY-3030D” manufactured by FLONTERLAB) are used. An integrated device can be used.

  In the configuration (1), the range of the surface layer of the toner particles is determined by the conditions of time-of-flight secondary ion mass spectrometry described later. The range of the surface layer is, for example, a range from the surface of the toner particle to the inside of the toner particle up to 1 nm under the measurement conditions of the examples described later. In time-of-flight secondary ion mass spectrometry, image-mapped data (image data) can be easily acquired. For this reason, by analyzing the surface of the toner particles by time-of-flight secondary ion mass spectrometry, it is possible to easily measure the types of molecules present at each position on the surface of the toner particles and the abundance of the molecules. It becomes possible.

  Configuration (1) is useful for improving the developability and storage stability of the toner. In the toner having the configuration (1), the ratio B is 120 ppm or less. In the toner having the configuration (1), since the content of the quaternary ammonium salt in the whole toner particles (inner and surface layers) is small, the charge amount of the toner tends not to decrease even when the toner is charged. For this reason, the toner having the configuration (1) is considered to be excellent in developability.

  In the toner having the configuration (1), the ratio A is 200 ppm or less. In the toner having the configuration (1), since the content of the quaternary ammonium salt in the surface layer of the toner particles is small, water tends to hardly adhere to the surface of the toner particles. For this reason, the toner having the configuration (1) is considered to have excellent storage stability.

  Further, in the toner having the configuration (1), the ratio A is 10 ppm or more, and the ratio B is 5 ppm or more. In the toner having the constitution (1), since the content of the quaternary ammonium salt in the surface layer of the toner particles and in the whole is not too small, the charge amount of the toner is hardly increased even when the toner is charged. There is a tendency that the charge-up phenomenon hardly occurs. For this reason, the toner having the configuration (1) is considered to be excellent in developability.

  If the amount of the quaternary ammonium salt present in the surface layer of the toner particles is too large, the developability of the toner tends to deteriorate. This is thought to be because the hygroscopicity of the toner particle surface increases. Further, if the amount of the quaternary ammonium salt present in the surface layer of the toner particles is too large, the storage stability of the toner tends to deteriorate. This is considered because the quaternary ammonium salt functions as a plasticizer. In addition, when there is too much quaternary ammonium salt inside the toner particles, the quaternary ammonium salt tends to move from the inside of the toner particles to the surface layer of the toner particles by continuous printing. Further, due to such movement, after continuous printing, the amount of quaternary ammonium salt present in the surface layer of the toner particles tends to increase more than before continuous printing, and the developability of the toner tends to deteriorate. In the toner having the configuration (1), the amount of the quaternary ammonium salt present in the toner particles is sufficiently small. For this reason, it is considered that excellent developability of the toner is maintained even after continuous printing.

  The ratio A is 10 ppm or more and 200 ppm or less, and preferably 10 ppm or more and 100 ppm or less. The ratio B is 5 ppm or more and 120 ppm or less, and preferably 5 ppm or more and 80 ppm or less.

  The toner according to the present embodiment includes a plurality of toner particles having the configuration (1) (hereinafter referred to as toner particles according to the present embodiment). The toner having toner particles of the present embodiment is excellent in developability and storage stability (see Table 2 described later). The toner preferably has the toner particles of the present embodiment at a ratio of 80% by number or more, more preferably has the toner particles of the present embodiment at a ratio of 90% by number or more, and a ratio of 100% by number. It is more preferable to have the toner particles of this embodiment.

  The toner particles contained in the toner may be toner particles having no shell layer (hereinafter referred to as non-capsule toner particles), or toner particles having a shell layer (hereinafter referred to as capsule toner particles). Yes). The capsule toner particle has a toner core and a shell layer that covers the surface of the toner core. An external additive may be attached to the surface of the shell layer. The shell layer may cover the entire surface of the toner core or may partially cover the surface of the toner core. A plurality of shell layers may be laminated on the surface of the toner core. If not necessary, the external additive may be omitted. Hereinafter, the toner particles before the external additive adheres may be referred to as toner mother particles.

In order to further improve the developability and storage stability of the toner, the toner preferably has the following configuration (2) in addition to the configuration (1).
Configuration (2): The core portion of the toner particles is produced by a pulverization method. The pulverization method includes a step of mixing a plurality of types of materials (resins, etc.) to obtain a mixture, a step of melt kneading the obtained mixture to obtain a kneaded product, and a step of pulverizing the obtained kneaded product. To obtain a powder (for example, toner particles or toner core). The pulverization method is a dry method.

  Configuration (2) is beneficial to satisfy ratio B in configuration (1). In the pulverization method, toner particles can be prepared without using any dispersant (for example, a surfactant) (or with only a small amount of dispersant). For this reason, when the toner particles are produced by the pulverization method, the content of the quaternary ammonium salt in the entire toner particles (particularly, inside the toner particles) can be reduced. In the non-capsule toner particles, the core portion of the toner particles corresponds to the toner base particles. In the capsule toner particles, the core part of the toner particles corresponds to the toner core.

  The toner may be used as a one-component developer. Further, a two-component developer may be prepared by mixing toner with a desired carrier. The toner may be used as a positively chargeable toner.

  Hereinafter, the toner core, the shell layer, and the external additive will be described in order. Further, a toner manufacturing method will be described. For non-capsule toner particles, the following toner core can be used as toner base particles. Acrylic and methacrylic are sometimes collectively referred to as “(meth) acrylic”. In addition, a compound and a derivative thereof 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.

[Toner core]
The toner core includes a binder resin. The toner core may contain an internal additive (for example, a colorant, a release agent, a charge control agent, or a magnetic powder) in addition to the binder resin. Hereinafter, the binder resin, the colorant, the release agent, the charge control agent, and the magnetic powder will be described.

(Binder resin)
In the toner core, 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 core. For example, when the binder resin has an ester group, a hydroxyl group, an ether group, an acid group, or a methyl group, the toner core tends to be anionic, and the binder resin has an amino group or an amide group. In other words, the toner core tends to become cationic. In order for the binder resin to have a strong anionic property, the hydroxyl value (OHV value) and the acid value (AV value) of the binder resin are each preferably 10 mgKOH / g or more, and each 20 mgKOH / g or more. Is more preferable. Further, an anionic compound (for example, a compound having an ester group, a hydroxyl group, an ether group, an acid group, or a methyl group) may be added to the toner core to impart anionicity to the toner core. Alternatively, a cationic compound (for example, a compound having an amino group or an amide group (more specifically, an amine)) may be added to the toner core to impart cationicity to the toner core.

  The binder resin is preferably a resin having one or more functional groups selected from the group consisting of an ester group, a hydroxyl group, an ether group, an acid group (more specifically, a carboxyl group) and a methyl group. And / or a resin having a carboxyl group is more preferred. A binder resin having such a functional group easily reacts with a material for forming a shell layer (hereinafter sometimes simply referred to as “shell layer material”) and is chemically bonded easily. When such a chemical bond occurs, the bond between the toner core and the shell layer becomes strong. Further, as the binder resin, a resin having a functional group containing active hydrogen in the molecule is also preferable.

  The glass transition point (Tg) of the binder resin is preferably 30 ° C. or higher and 80 ° C. or lower. The glass transition point (Tg) of the binder resin is preferably equal to or lower than the curing start temperature of the shell layer material. When such a binder resin having Tg is used, it is considered that the toner fixability is unlikely to deteriorate even during high-speed fixing on a recording medium.

  The Tg of the binder resin can be measured using, for example, a differential scanning calorimeter. More specifically, by measuring the endothermic curve of the sample (binder resin) using a differential scanning calorimeter, the Tg of the binder resin can be obtained from the change point of specific heat in the obtained endothermic curve.

  The softening point (Tm) of the binder resin is preferably 120 ° C. or lower. When the Tm of the binder resin is 120 ° C. or less, the toner fixability is hardly lowered even during high-speed fixing on the recording medium. Further, when the Tm of the binder resin is 120 ° C. or lower, the toner core is likely to be partially softened during the curing reaction of the shell layer when the shell layer is formed on the surface of the toner core in the aqueous medium. The toner core is easily rounded by surface tension. In addition, Tm of binder resin can be adjusted by combining several resin which has different Tm.

The Tm of the binder resin can be measured using, for example, a Koka type flow tester (more specifically, “CFT-500D” manufactured by Shimadzu Corporation). More specifically, a sample (binder resin) is set in the Koka flow tester, and the binder resin is melted and discharged under predetermined conditions. Then, the S-curve of the binder resin is measured. The Tm of the binder resin can be 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”. The temperature (° C.) at which corresponds to the Tm of the measurement sample (binder resin).

  As the binder resin, a thermoplastic resin or a crosslinked product of a thermoplastic resin is preferable. Preferable examples of the thermoplastic resin that can be used as the binder resin include a styrene resin, an acrylic acid resin, an olefin resin (more specifically, a polyethylene resin or a polypropylene resin), a vinyl resin (more specifically, Specifically, a vinyl chloride resin, a polyvinyl alcohol resin, a vinyl ether resin, or an N-vinyl resin), a polyester resin, a polyamide resin, a urethane resin, a styrene-acrylic acid resin, a styrene butadiene resin, or a cross-linked product thereof. Can be mentioned. Among them, the cross-linked product of styrene-acrylic acid resin and the polyester resin are excellent in the dispersibility of the colorant in the toner, the charging property of the toner, and the fixing property of the toner to the recording medium.

  Hereinafter, a styrene-acrylic acid resin that can be used as a binder resin and a crosslinked product thereof will be described. The styrene-acrylic acid resin is a copolymer of a styrene monomer and an acrylic acid monomer.

  Suitable examples of the styrenic monomer include styrene, α-methylstyrene, p-hydroxystyrene, m-hydroxystyrene, vinyltoluene, α-chlorostyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, Or p-ethylstyrene is mentioned.

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

  When preparing a styrene-acrylic acid resin, a monomer having a hydroxyl group (for example, p-hydroxystyrene, m-hydroxystyrene, or (meth) acrylic acid hydroxyalkyl ester) is used, so that the styrene-acrylic acid resin is used. Hydroxyl groups can be introduced into the. Moreover, the hydroxyl value of the styrene-acrylic acid-type resin obtained can be adjusted by adjusting the usage-amount of the monomer which has a hydroxyl group.

  When preparing the styrene-acrylic acid resin, a carboxyl group can be introduced into the styrene-acrylic acid resin by using (meth) acrylic acid (monomer). Moreover, the acid value of the styrene-acrylic acid-type resin obtained can be adjusted by adjusting the usage-amount of (meth) acrylic acid.

  By adding a crosslinking agent to the styrene monomer or acrylic acid monomer, a crosslinked product of the thermoplastic resin can be prepared. Examples of the crosslinking agent for introducing a crosslinked structure into the thermoplastic resin include a crosslinking monomer. Examples of the crosslinkable monomer include divinylbenzene crosslinkable monomers, diallyl phthalate crosslinkable monomers, and dimethacrylate crosslinkable monomers. Examples of the divinylbenzene-based crosslinking monomer include o-divinylbenzene, m-divinylbenzene, and p-divinylbenzene. Examples of the diallyl phthalate crosslinkable monomer include diallyl isophthalate and diallyl orthophthalate. Examples of the dimethacrylic acid ester-based crosslinking monomer include ethylene glycol dimethacrylate or triethylene glycol dimethacrylate.

  When the binder resin is a styrene-acrylic acid resin, the number average molecular weight (Mn) of the styrene-acrylic acid resin is 2000 or more and 3000 or less in order to achieve both the strength of the toner core and the fixing property of the toner. Is preferred. The molecular weight distribution (the ratio Mw / Mn of the weight average molecular weight (Mw) to the number average molecular weight (Mn)) of the styrene-acrylic acid resin is preferably 10 or more and 20 or less. Gel permeation chromatography can be used to measure Mn and Mw of the styrene-acrylic acid resin.

  Hereinafter, the polyester resin that can be used as the binder resin will be described. The polyester resin can be obtained by polycondensation or copolycondensation of a divalent or trivalent or higher alcohol and a divalent or trivalent or higher carboxylic acid.

  Examples of dihydric alcohols that can be used to prepare the polyester resin include diols or bisphenols.

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

  Preferable examples of bisphenols include bisphenol A, hydrogenated bisphenol A, polyoxyethylene bisphenol A, or polyoxypropylene bisphenol A.

  Suitable examples of trihydric or higher alcohols that can be used to prepare the polyester resin include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, Tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, diglycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, Examples include trimethylolpropane or 1,3,5-trihydroxymethylbenzene.

  Suitable examples of divalent carboxylic acids that can be used to prepare the polyester resin include 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, or isododecyl succinic acid) Acid or the like) or alkenyl succinic acid (specifically, n-butenyl succinic acid, isobutenyl succinic acid, n-octenyl succinic acid, n-dodecenyl succinic acid, or isododecenyl succinic acid, etc.).

  Preferable examples of the trivalent or higher carboxylic acid that can be used for preparing the polyester resin include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, 1 , 2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, 1,2, Examples include 4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, or empole trimer acid.

  The divalent or trivalent or higher carboxylic acid may be used as an ester-forming derivative (for example, acid halide, acid anhydride, or lower alkyl ester). Here, “lower alkyl” means an alkyl group having 1 to 6 carbon atoms.

  When preparing the polyester resin, the acid value and hydroxyl value of the polyester resin can be adjusted by changing the amount of alcohol used and the amount of carboxylic acid used. When the molecular weight of the polyester resin is increased, the acid value and hydroxyl value of the polyester resin tend to decrease.

  When the binder resin is a polyester resin, the number average molecular weight (Mn) of the polyester resin is preferably 1000 or more and 2000 or less in order to achieve both the strength of the toner core and the fixing property of the toner. The molecular weight distribution of the polyester resin (the ratio Mw / Mn of the weight average molecular weight (Mw) to the number average molecular weight (Mn)) is preferably 9 or more and 21 or less. Gel permeation chromatography can be used for the measurement of Mn and Mw of the polyester resin.

(Coloring agent)
The toner core may contain a colorant. As the colorant, for example, a known pigment or dye can be used according to the color of the toner. The amount of the colorant to be used is preferably 1 part by mass or more and 20 parts by mass or less, and more preferably 3 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the binder resin.

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

  Examples of yellow colorants include condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, or arylamide compounds. Suitable examples of yellow colorants 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. Bat yellow is mentioned.

  Examples of magenta colorants include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, or perylene compounds. Suitable examples of magenta colorants 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).

  Examples of cyan colorants include copper phthalocyanine compounds, anthraquinone compounds, or basic dye lake compounds. Suitable 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.

(Release agent)
The toner core 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 increase the anionicity of the toner core, it is preferable to produce the toner core using an anionic wax. In order to improve the fixing property or offset resistance of the toner, the amount of the release agent used 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. More preferably, it is 10 parts by mass or less.

  Preferable 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 an oxide of an aliphatic hydrocarbon wax such as a block copolymer of oxidized polyethylene wax; a plant wax such as candelilla wax, carnauba wax, wood wax, jojoba wax, or rice wax; beeswax, lanolin, or Animal waxes such as whale wax; mineral waxes such as ozokerite, ceresin, or petrolatum; waxes based on fatty acid esters such as montanate wax or castor wax; Such as carnauba wax, part or all of fatty acid esters are de-oxidized waxes.

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

(Charge control agent)
The toner core may contain a charge control agent. The charge control agent is used, for example, for the purpose of improving the charging stability or charge rising property of the toner. The toner charge rising property is an index of whether or not the toner can be charged to a predetermined charge level in a short time. Further, the anionic property of the toner core can be enhanced by including a negatively chargeable charge control agent in the toner core.

(Magnetic powder)
The toner core may contain magnetic powder. Examples of magnetic powders include iron (more specifically, ferrite or magnetite), ferromagnetic metal (more specifically, cobalt or nickel), a compound containing iron and / or ferromagnetic metal (more specifically, In particular, an alloy or the like), a ferromagnetic alloy that has been subjected to a ferromagnetization treatment (more specifically, a heat treatment or the like), or chromium dioxide.

  In order to suppress elution of metal ions (for example, iron ions) from the magnetic powder, it is preferable to surface-treat the magnetic powder. When a shell layer is formed on the surface of the toner core under acidic conditions, if a metal ion adheres to the surface of the toner core, the toner core and another toner core are easily fixed. By suppressing the elution of metal ions from the magnetic powder, it is possible to suppress adhesion between the toner core and another toner core.

[Shell layer]
The shell layer can include a thermoplastic resin. In order to improve the film quality of the shell layer, the thermoplastic resin preferably includes an acrylic acid-based monomer, and more preferably includes a reactive acrylic ester.

<Thermoplastic resin>
Specific examples of the thermoplastic resin include acrylic acid resins, styrene-acrylic acid resins, silicone-acrylic acid graft copolymers, urethane resins, polyester resins, and ethylene-vinyl alcohol copolymers. As the thermoplastic resin, an acrylic resin, a styrene-acrylic resin, or a silicone-acrylic graft copolymer is preferable, and a styrene-acrylic resin is more preferable.

  Examples of acrylic monomers that can be used to introduce a thermoplastic resin into the shell layer include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, or (meth ) (Meth) acrylic acid alkyl esters such as n-butyl acrylate; (meth) acrylic aryl esters such as phenyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate, (meth) acrylic acid 3 (Meth) acrylic acid hydroxyalkyl esters such as hydroxypropyl, 2-hydroxypropyl (meth) acrylate, or 4-hydroxybutyl (meth) acrylate; (meth) acrylamide; ethylene oxide adducts of (meth) acrylic acid Methyl ether, ethyl ether, n-propyl ether, or - like ether include alkyl ethers of ethylene oxide adducts of (meth) acrylic acid ester.

  The amount of the thermoplastic resin is preferably 10 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the toner core.

[External additive]
An external additive may be attached to the surface of the toner particles as necessary. As an external additive,
For example, metal oxide (more specifically, alumina, titanium oxide, magnesium oxide, zinc oxide, strontium titanate, barium titanate, or the like) or silica fine particles can be used.

  The volume median diameter of the external additive is preferably 0.01 μm or more and 1.0 μm or less. The amount of the external additive used is preferably 0.5 parts by mass or more and 10 parts by mass or less, more preferably 1 part by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the toner base particles.

  A two-component developer can be prepared by mixing the toner of this embodiment with a desired carrier. When preparing a two-component developer, it is preferable to use a magnetic carrier.

  An example of a suitable carrier is a carrier having a carrier core coated with a resin. Specific examples of carrier cores include iron, oxidized iron, reduced iron, magnetite, copper, silicon steel, ferrite, nickel, or cobalt particles; alloys of these materials with metals such as manganese, zinc, or aluminum Particles of iron-nickel alloy or iron-cobalt alloy; ceramics (titanium oxide, aluminum oxide, copper oxide, magnesium oxide, lead oxide, zirconium oxide, silicon carbide, magnesium titanate, barium titanate, lithium titanate , Particles of lead titanate, lead zirconate, or lithium niobate); particles of a high dielectric constant material (ammonium dihydrogen phosphate, potassium dihydrogen phosphate, or Rochelle salt). A resin carrier may be prepared by dispersing the particles in a resin.

  Examples of the resin that coats the carrier core include acrylic acid polymers, styrene polymers, styrene-acrylic acid resins, olefin polymers (more specifically, polyethylene, chlorinated polyethylene, polypropylene, etc.) , Polyvinyl chloride, polyvinyl acetate, polycarbonate resin, cellulose resin, polyester resin, unsaturated polyester resin, polyamide resin, urethane resin, epoxy resin, silicone resin, fluorine resin (more specifically, polytetrafluoroethylene, poly Chlorotrifluoroethylene or polyvinylidene fluoride), phenol resin, xylene resin, diallyl phthalate resin, polyacetal resin, or amino resin. Two or more of these resins may be combined.

  The volume median diameter of the carrier measured by an electron microscope is preferably 20 μm or more and 120 μm or less, and more preferably 25 μm or more and 80 μm or less.

  When preparing a two-component developer using a toner and a carrier, the toner content is preferably 3% by mass or more and 20% by mass or less with respect to the mass of the two-component developer. It is preferable that it is 15 mass% or less.

[Toner Production Method]
Hereinafter, a toner manufacturing method will be described. When the toner particles contained in the toner are capsule toner particles, the toner manufacturing method includes, for example, a toner core manufacturing step, a shell layer forming step, and a cleaning step. In the toner core manufacturing step, a toner core is manufactured. In the shell layer forming step, a shell layer is formed on the surface of the toner core in an aqueous medium. 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 solvent). 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. As the aqueous medium, water is preferable from the viewpoint of suppressing dissolution of the binder resin or elution of the release agent.

(Toner core manufacturing process)
As the toner core production process, for example, a pulverization method and an aggregation method are preferable.

  In the pulverization method, a binder resin and an internal additive (for example, a colorant, a release agent, a charge control agent, or magnetic powder) are mixed. Subsequently, the obtained mixture is melted and kneaded. Subsequently, the obtained kneaded material is pulverized. Subsequently, the obtained pulverized product is classified. As a result, a toner core having a desired particle size can be obtained. According to the pulverization method, the toner core can be prepared relatively easily. The toner core is preferably produced by a pulverization method. Since the pulverization method can reduce the amount of a dispersant (for example, a surfactant) used compared to the aggregation method, the content of the quaternary ammonium salt inside the toner particles can be reduced.

  The aggregation method includes, for example, an aggregation process and a coalescence process. In the aggregating step, a plurality of types of fine particles, which are finely divided for each component constituting the toner core, are agglomerated in an aqueous medium to form agglomerated particles including a plurality of types of toner core components. In the coalescence process, the components contained in the aggregated particles are coalesced in an aqueous medium to obtain a toner core. According to the aggregation method, it is easy to obtain a toner core having a uniform shape and a uniform particle diameter. In the aggregation method, a quaternary ammonium salt may be used as a dispersant.

(Shell layer forming process)
In the shell formation step, first, the toner core obtained in the toner core preparation step, the material of the shell layer, and the quaternary ammonium salt are added to an aqueous medium to prepare a toner core dispersion. As a material for the shell layer, for example, thermoplastic resin particles are added. In the aqueous medium, the thermoplastic resin particles adhere to the surface of the toner core.

  The volume median diameter of the thermoplastic resin particles is preferably 20 nm or more and 100 nm or less. When the volume median diameter of the thermoplastic resin particles is 20 nm or more and 100 nm or less, it is easy to appropriately adjust the content of the quaternary ammonium salt that adheres to the surface area of the thermoplastic resin particles and is taken into the shell layer.

The quaternary ammonium salt has a hydrophobic group and a quaternary ammonium group as a hydrophilic group. Examples of such quaternary ammonium salts include alkyl trimethyl ammonium salts, dialkyl dimethyl ammonium salts, and alkyl benzyl dimethyl ammonium salts. The alkyl group in these quaternary ammonium salts may be linear or branched, but is preferably linear. Examples of the alkyl group in these quaternary ammonium salts include octyl group, decyl group, dodecyl group, tetradecyl group, hexadecyl group, octadecyl group, icosyl group or docosyl group. Examples of counter ions in these quaternary ammonium salts include inorganic ions and organic ions. Examples of inorganic ions include halogen ions (more specifically, chloride ions or bromide ions). Examples of the organic ions include nitrate ions (NO ₃ ⁻ ), sulfate ions, and (SO ₄ ²⁻ ). Of these counter ions, chloride ions or bromide ions are preferred.

  The alkyl trimethyl ammonium salt is a quaternary ammonium salt in which one alkyl group and three methyl groups are bonded to a nitrogen atom. Examples of the alkyl group in the alkyltrimethylammonium salt include an alkyl group having 12 to 22 carbon atoms, and a linear alkyl group having 12 to 22 carbon atoms is preferable. Examples of alkyltrimethylammonium salts include dodecyltrimethylammonium salts (more specifically, dodecyltrimethylammonium bromide or dodecyltrimethylammonium chloride), hexadecyltrimethylammonium salts (more specifically, hexadecyltrimethylammonium bromide, etc.). ) Or octadecyltrimethylammonium salt.

  The zirconium alkyl dimethyl ammonium salt is a quaternary ammonium salt in which two alkyl groups and two methyl groups are bonded to a nitrogen atom. Examples of the alkyl group in the dialkyldimethylammonium salt include an alkyl group having 8 to 18 carbon atoms, and a linear alkyl group having 8 to 18 carbon atoms is preferable. Examples of the dialkylbenzyldimethylammonium salt include didecyldimethylammonium salt.

  The alkylbenzyldimethylammonium salt is a quaternary ammonium salt in which one alkyl group, one benzyl group, and two methyl groups are bonded to a nitrogen atom. Examples of the alkyl group in the alkylbenzyldimethylammonium salt include an alkyl group having 12 to 16 carbon atoms, and a linear alkyl group having 12 to 16 carbon atoms is preferable. Examples of the alkylbenzyldimethylammonium salt include dodecylbenzyldimethylammonium salt, tetradecylbenzyldimethylammonium salt, and hexadecylbenzyldimethylammonium salt.

  The concentration of the quaternary ammonium salt (the concentration of the dispersant) is preferably 3% by mass or more and 10% by mass or less with respect to the aqueous medium.

  Subsequently, while stirring the prepared dispersion liquid of the toner core, the temperature of the dispersion liquid is raised to a predetermined temperature and maintained at that temperature for a predetermined time. Thereby, the material of the shell layer attached to the surface of the toner core is cured by the polymerization reaction. As a result, a shell layer is formed on the surface of the toner core, and a dispersion of toner mother particles is obtained.

  Examples of a method for satisfactorily dispersing the toner core in the aqueous medium include a method in which the toner core is mechanically dispersed in the aqueous medium using an apparatus capable of vigorously stirring the dispersion.

  The pH of the aqueous medium is preferably adjusted to about 4 using an acidic substance before adding the shell layer material. By adjusting the pH of the aqueous medium to the acidic side, the polymerization reaction for forming the shell layer is promoted.

  In order to make the formation of the shell layer well, the temperature at which the shell layer is formed on the surface of the toner core is preferably 40 ° C. or more and 95 ° C. or less, more preferably 50 ° C. or more and 80 ° C. or less. preferable.

(Washing process)
In the cleaning step, the toner base particles are cleaned with a cleaning liquid. After the shell layer is formed as described above, the dispersion liquid containing the toner base particles is cooled to room temperature (for example, 25 ° C.). Thereafter, the toner base particles are washed with a washing liquid.

  In the cleaning step, the toner base particles are cleaned using a cleaning liquid. Examples of the cleaning liquid include water, and high-purity water (specifically, ion-exchanged water or the like) is preferable. As a preferred cleaning method, a method of recovering wet cake-like toner mother particles from a dispersion containing toner mother particles by solid-liquid separation, and washing the obtained wet cake-like toner mother particles with water. And a method in which the toner base particles in the dispersion liquid are settled, the supernatant liquid is replaced with water, and the toner base particles are re-dispersed in water after the replacement. By washing the toner base particles, the ratio of the quaternary ammonium salt in the surface layer of the shell layer can be reduced to a specific numerical range. The ratio A can be adjusted by, for example, the conductivity of the cleaning liquid after cleaning. The conductivity of the cleaning liquid after cleaning is preferably 1 μS / cm or more and 5 μS / cm or less.

  The toner manufacturing method according to the present embodiment includes a step of drying the toner base particles (drying step) and a step of attaching an external additive to the surface of the toner base particles (external addition) as necessary after the cleaning step. Through the process, the toner is recovered from the dispersion of toner base particles. In the drying step, the toner base particles are dried. Suitable methods for drying the toner base particles include a method using a dryer (for example, a spray dryer, a fluidized bed dryer, a vacuum freeze dryer, or a vacuum dryer). Among these methods, a method using a spray dryer is preferable in order to suppress aggregation of toner base particles during drying. When a spray dryer is used, the external additive can be attached to the surface of the toner base particles by spraying a dispersion of the external additive such as silica together with the dispersion of the toner base particles.

  In the external addition step, an external additive is attached to the surface of the toner base particles. As a suitable method for attaching the external additive, a toner (for example, FM mixer, Nauter mixer (registered trademark)) is used, under the condition that the external additive is not buried in the surface of the toner base particles. A method of mixing the base particles and the external additive can be mentioned.

  When the toner particles contained in the toner are non-capsule toner particles, the toner manufacturing method includes, for example, a toner base particle preparation step, an immersion step, and a cleaning step. In the toner base particle preparation step, toner base particles are prepared. Toner base particles can be prepared in the same manner as in the toner core preparation process described above.

  In the dipping step, the toner base particles are immersed in an aqueous medium solution of a quaternary ammonium salt. By combining the dipping process and the subsequent cleaning process, the ratio A can be adjusted to a specific numerical range. An aqueous medium solution of a quaternary ammonium salt in which toner base particles are immersed may be heated. When heating, the temperature of the aqueous medium solution is preferably 50 ° C. or higher and 90 ° C. or lower.

  In the cleaning step, the immersed toner base particles are cleaned. In the washing step, the same method as the washing step in the method for producing the toner having the core-shell structure described above is performed. After the washing step, an external additive may be attached to the surface of the toner base particles.

  The toner manufacturing method can be arbitrarily changed according to the required configuration or characteristics of the toner. For example, after the shell layer material is dissolved in a solvent, the toner core may be added to the solvent. Further, after adding the toner core to the solvent, the material of the shell layer may be dissolved in the solvent. The method for forming the shell layer is arbitrary. For example, the shell layer may be formed using any of an in-situ polymerization method, a submerged cured coating method, and a coacervation method. Further, various processes may be omitted depending on the use of the toner. When the external additive is not attached to the surface of the toner base particles (the step of external addition is omitted), the toner base particles correspond to the toner particles. In order to produce the toner efficiently, it is preferable to form a large number of toner particles simultaneously.

  Examples will be described below. Table 1 shows toners A-1 to A-3, toners B-1 to B-3, toners C-1 to C-3, and toners D-1 to D-3 (each toner for developing an electrostatic latent image). Show.

(Preparation of polyester resin A)
A four-necked flask was used as a reaction vessel. The four-necked flask is a 5 L reaction vessel equipped with a thermometer, a nitrogen introduction tube, a dehydration tube, a rectifying column, a stirring blade, and a thermocouple. The reaction vessel was set in an oil bath, and 1200 g of propanediol, 1,700 g of terephthalic acid, and 10 g of tin (II) dioctanoate esterification catalyst were charged into the reaction vessel. Subsequently, the internal temperature of the reaction vessel was raised to 230 ° C. using an oil bath. The internal temperature of the reaction vessel was maintained at 230 ° C., and a condensation reaction was performed in a nitrogen atmosphere for 15 hours. Furthermore, the internal temperature of the reaction vessel was maintained at 230 ° C., the pressure in the reaction vessel was 8.0 kPa, and a condensation reaction was performed for 1 hour. Thereafter, the internal temperature of the reaction vessel was cooled to 180 ° C., and 290 g of trimellitic anhydride was added to the reaction vessel. The internal temperature of the reaction vessel was raised to 210 ° C. over 3 hours. The internal temperature of the reaction vessel was maintained at 210 ° C., and the pressure in the reaction vessel was set to normal pressure (101 kPa), and a condensation reaction was performed for 10 hours. Subsequently, the internal temperature of the reaction vessel is maintained at 210 ° C., the pressure of the reaction vessel is set to 20 kPa, and a condensation reaction is performed until the softening point of the reaction product (polyester resin) reaches a desired temperature to obtain polyester resin A. It was. The Tm of the polyester resin A was 120 ° C.

(Toner A-1)
The following materials were mixed for 4 minutes using an FM mixer (“FM-20B” manufactured by Nippon Coke Industries, Ltd.) under the condition of a rotational speed of 2000 rpm.
Binder resin (polyester resin A synthesized by the above procedure): Amount added “80 parts by mass ”
Release agent (manufactured by NOF Corporation, "Nissan Elek Torr (TM) WEP-3" ingredients: ester wax): amount "9 parts by mass"
Colorant (Mitsubishi Chemical Corporation “MA-100”, component: carbon black): addition amount “9 parts by mass”

  The obtained mixture was melt-kneaded with a twin-screw extruder ("PCM-30" manufactured by Ikegai Co., Ltd.) under conditions of a melt kneading temperature (cylinder temperature) of 120 ° C, a rotation speed of 150 rpm, and a processing speed of 100 g / min. The obtained melt-kneaded product was coarsely pulverized to about 2 mm using a pulverizer ("Rohtoplex (registered trademark)" manufactured by Hosokawa Micron Corporation). The resulting coarsely pulverized product was pulverized using a pulverizer (“Turbo Mill (RS type)” manufactured by Freund Turbo Inc.). The conditions for pulverizing the coarsely pulverized product were as follows: a mill rotational speed of 12,000 rpm and an input amount of 2 kg / hour. The obtained pulverized product was classified with an air classifier (“EJ-L3 type” manufactured by Nittetsu Mining Co., Ltd.) to obtain particles A. Particle A had a Tm of 100 ° C. and a Tg of 49 ° C.

  The resin particle dispersion A produced by the following method was added to the particles A obtained so that the mass ratio was 10% by mass. Furthermore, a 0.1% by mass aqueous solution of sodium lauryl sulfate was added to the particles A so as to have a solid content concentration of 30% by mass to prepare a dispersion. Subsequently, the obtained dispersion was heated to 70 ° C. and then cooled to room temperature. The cooled dispersion was subjected to solid-liquid separation, and the separated solid was washed so that the conductivity of the washing liquid was 1 μS / cm, and then dried. As a result, toner mother particles A were obtained.

  The resin fine particle dispersion A was prepared as follows. A three-necked flask was prepared as a reaction vessel. This three-necked flask was a 1 L capacity reaction vessel equipped with a thermometer and stirring blades. The reaction vessel was set in a water bath. 820 mL of ion-exchanged water and 75 mL of a cationic surfactant (“Cotamine (registered trademark) 24P” manufactured by Kao Corporation, dodecyltrimethylammonium chloride) were added to the reaction vessel, and the temperature inside the flask was raised to 80 ° C. Further, a mixed solution of 70 mL of styrene and 12 mL of butyl acrylate and a solution prepared by dissolving 0.5 g of potassium persulfate in 30 mL of ion-exchanged water were dropped into the reaction vessel for 5 hours each. The temperature inside the flask was kept at 80 ° C. for 2 hours to complete the polymerization, and a resin fine particle dispersion A in which styrene-acrylic acid resin particles were dispersed was obtained. The Tg of the resin fine particles was 70 ° C.

The following materials were stirred using an FM mixer (“FM-10B” manufactured by Nippon Coke Industries, Ltd.) to obtain toner A-1.
Toner base particle A: addition amount “100 parts by mass”
External additive (“EC-100” titanium oxide manufactured by Titanium Industry Co., Ltd.): Addition amount “0.8 parts by mass”
External additive (“RA-200-H” silica manufactured by Nippon Aerosil Co., Ltd.): addition amount “1.2 parts by mass”

(Toner A-2)
The toner A-2 is manufactured in the same manner as in the production of the toner A-1 except that the cleaning end condition is changed from the time when the conductivity of the cleaning liquid becomes 1 μS / cm to the time when the conductivity of the cleaning liquid becomes 3 μS / cm. Manufactured.

(Toner A-3)
Toner A-3 was prepared in the same manner as in the production of toner A-1, except that the cleaning end condition was changed from the cleaning liquid conductivity of 1 μS / cm to the cleaning liquid conductivity of 5 μS / cm. Manufactured.

(Toner B-1)
The resin fine particle dispersion A (mass ratio: 10 mass%) added to the particles A is changed to the resin particle dispersion B (mass ratio: 12 mass%), and the temperature of the heated dispersion liquid is changed from 60 ° C. to 70 ° C. Except for the change, Toner B-1 was obtained in the same manner as in the production method of Toner A-1. A resin fine particle dispersion B was obtained in the same manner as the resin fine particle dispersion A except that the volume of the cationic surfactant was changed from 75 mL to 65 mL and the flask internal temperature was changed from 80 ° C. to 78 ° C. . The Tg of the resin fine particles was 74 ° C.

(Toner B-2)
The toner B-2 was prepared in the same manner as in the production of the toner B-1, except that the cleaning end condition was changed from the cleaning liquid conductivity of 1 μS / cm to the cleaning liquid conductivity of 3 μS / cm. Manufactured.

(Toner B-3)
Toner B-3 was prepared in the same manner as in the production of toner B-1, except that the cleaning end condition was changed from the cleaning liquid conductivity of 1 μS / cm to the cleaning liquid conductivity of 5 μS / cm. Manufactured.

(Toner C-1)
The following materials were dispersed with a TK homomixer (manufactured by PRIMIX Co., Ltd.) for 1 hour under the conditions of a rotational speed of 15000 rpm and a nitrogen atmosphere.
・ Binder resin preparation monomer (styrene): Addition amount “60 parts by mass”
・ Binder resin preparation monomer (dimethylaminoethyl methacrylate): “5 parts by mass” added
Colorant ("MA-100" carbon black manufactured by Mitsubishi Chemical Corporation): Addition amount "10 parts by mass"

  In the obtained dispersion, 20 parts by mass of resin particles for forming a binder resin (styrene-acrylic acid resin particles) were dissolved, and 5 parts by mass of benzoyl peroxide was further added and dissolved while stirring. A colorant-dispersed monomer solution was obtained. 20 parts by weight of the obtained colorant-dispersed monomer solution was added dropwise to 80 parts by weight of a 2% by weight aqueous solution of dodecyltrimethylammonium chloride prepared separately. A colorant was dispersed for 5 minutes under the condition of a rotational speed of 8000 rpm with a homogenizer (“Ultra Turrax T50” manufactured by IKA) to obtain a suspended fine particle dispersion. The volume median diameter of the suspended fine particles was 7.9 μm. The suspended fine particles were heated to 70 ° C. in a nitrogen atmosphere and at a rotation speed of 200 rpm, and a polymerization reaction was performed for 10 hours. Subsequently, it was cooled, washed so that the conductivity of the cleaning solution was 1 μS / cm, and then dried. As a result, toner C-1 was obtained.

(Toner C-2)
The toner C-2 was prepared in the same manner as in the production of the toner C-1, except that the cleaning end condition was changed from the cleaning liquid conductivity of 1 μS / cm to the cleaning liquid conductivity of 3 μS / cm. Manufactured.

(Toner C-3)
The toner C-3 was prepared in the same manner as in the production of the toner C-1, except that the cleaning end condition was changed from the cleaning liquid conductivity of 1 μS / cm to the cleaning liquid conductivity of 5 μS / cm. Manufactured.

(Toner D-1)
An 8% by mass aqueous solution of a cationic surfactant (“Coatamine (registered trademark) 24P” manufactured by Kao Corporation, dodecyltrimethylammonium chloride) manufactured by Kao Corporation) is added to the toner base particle A so that the mass ratio to the toner base particle A is 10% by mass. did. Further, a 0.1% by mass aqueous sodium lauryl sulfate solution was added so that the toner base particles A had a solid content concentration of 30% by mass. The toner base particles A were subjected to solid-liquid separation, and the separated toner base particles A were washed so that the conductivity of the cleaning liquid was 1 μS / cm, and then dried.

(Toner D-2)
The toner D-2 was prepared in the same manner as in the production of the toner D-1, except that the cleaning end conditions were changed from the cleaning liquid conductivity of 1 μS / cm to the cleaning liquid conductivity of 3 μS / cm. Manufactured.

(Toner D-3)
The toner D-3 was prepared in the same manner as in the production of the toner D-1, except that the cleaning end condition was changed from the cleaning liquid conductivity of 1 μS / cm to the cleaning liquid conductivity of 5 μS / cm. Manufactured.

[Evaluation method]
The evaluation method for each sample (toners A-1 to D-3) is as follows.

(Ratio A)
The ratio A was measured using a time-of-flight secondary ion mass spectrometer (“IV type” manufactured by ION-TOF) under the following conditions. The sample (toner) was fixed on a double-sided tape, and was set on the sample installation part of the above-mentioned time-of-flight secondary ion mass spectrometer. Under the conditions of the primary ion species Bi ³⁺ , the acceleration voltage 25 kV, and the irradiation current 0.1 pA, the sample in the sample installation portion was irradiated with the primary ion beam. When the sample was irradiated with the primary ion beam, secondary ions emitted from the sample were collected under the conditions of an analysis visual field side of 50 nm and an integration time of 30 seconds (10 scans). Thereby, the mass spectrum of the secondary ion was measured. A mass spectrum of 10 fields per sample was measured. A calibration curve was prepared using the standardized sample. After standardizing the mass spectrum using a calibration curve, the amount of ions derived from a quaternary ammonium salt was obtained. The average value of the ion amount was obtained from the obtained ion amount. The average value of the obtained ion amount was defined as the ratio A. The method for creating a calibration curve is not particularly limited, and examples thereof include an absolute calibration curve method, a relative calibration curve method, an internal standard method, and an external standardization method.

(Percentage B)
As a measuring apparatus, an apparatus in which a gas chromatograph mass spectrometer (“GCMS-QP2010Ultra” manufactured by Shimadzu Corporation) and a thermal decomposition apparatus (“EGA / PY-3030D” manufactured by FLONTERLAB) were integrated was used. .

A pyrolysis method was used. 100 μg of a sample (toner) was set in a thermal decomposition apparatus (pyrolyzer). The sample was volatilized under the following conditions, and volatile components were introduced into the gas chromatograph.
Pyrolyzer: 600 ° C
Interface: 320 ° C

Volatile components and carrier gas were introduced from the inlet of the gas chromatograph. Volatile components were separated by a column under the following conditions.
Column DB-5MS (length 30 m, film thickness 0.25 μm, inner diameter 0.25 mm)
Carrier gas: Helium (He)
Flow rate conditions: 1 mL / min Temperature of vaporization chamber: 320 ° C
Column oven temperature condition: 40 ° C-28 ° C / min-320 ° C

The components separated by the gas chromatograph were ionized under the following conditions and detected with a mass spectrometer, and the mass spectrum was measured. A ratio (ppm) derived from the sulfone group-containing compound and the sulfate group-containing compound was obtained from the mass spectrum. This measurement was performed 10 times. An average value was obtained from the obtained ratio. The average value obtained was defined as the ratio B.
Interface temperature: 320 ° C
Ion source temperature: 200 ° C
Detection mode: Scan 29-350 m / sec Scanning mass range: 45 m / z or more and 500 m / z or less

(conductivity)
The conductivity was measured using an electric conductivity meter (“ES-51” manufactured by Horiba, Ltd.).

(Volume median diameter (D ₅₀ ))
The volume median diameter was measured using a precision particle size distribution analyzer (“Coulter Counter Multisizer 3” manufactured by Beckman Coulter, Inc.).

(Glass transition point (Tg))
The glass transition point (Tg) was measured using a differential calorimeter (“DSC-6220” manufactured by Seiko Instruments Inc.).

(Storability)
2 g of the sample (toner) was weighed into a 20 mL capacity plastic container and allowed to stand in a thermostat set at 50 ° C. for 3 hours to obtain a sample for storage stability evaluation. Then, the sample for storage stability evaluation was sieved using a sieve of 100 mesh (aperture 150 μm) under the condition of amplitude 2 and time 30 seconds according to the manual of a powder tester (manufactured by Hosokawa Micron Corporation). After sieving, the mass of the sample remaining on the sieve was measured. From the mass of the sample before sieving and the mass of the sample remaining on the sieving after sieving, the degree of aggregation (% by mass) of the toner was calculated according to the following formula.
Aggregation degree (mass%) = (mass of sample remaining on sieve / mass of sample before sieving) × 100
From the calculated degree of aggregation, the storage stability of the toner was evaluated according to the following criteria.
○ (Good): The degree of aggregation was 20% by mass or less.
X (Poor): Aggregation degree exceeded 20 mass%.

(Adhesion resistance: sleeve resistance, drum resistance, spent resistance)
A developer carrier (a carrier for a multifunction machine “TASKalfa7551ci” manufactured by Kyocera Document Solutions Co., Ltd.) and a sample (toner) are mixed for 30 minutes using a ball mill, and two-component development with a toner content of 10% by mass is performed. An agent was prepared. Then, an image was formed using the obtained two-component developer, and the toner adhesion resistance (sleeve resistance, drum resistance, and spent resistance) was evaluated. As the evaluation machine, “TASKAlfa 7551ci” manufactured by Kyocera Document Solutions Co., Ltd. was used. The two-component developer prepared as described above was charged into the developing device of the evaluation machine, and a sample (replenishment toner) was charged into the toner container of the evaluation machine.

Using the evaluation machine, continuous printing at a printing rate of 10% was performed on 100,000 sheets of paper (A4 size printing paper) in an environment of normal temperature and normal humidity (temperature 25 ° C., humidity 50% RH). Thereafter, the surfaces of the developing sleeve and the photosensitive drum of the evaluator were visually observed, and the sleeve resistance and drum resistance of the sample (toner) were evaluated according to the following criteria.
The evaluation criteria for the resistance to sleeve adhesion were as follows. The vertical stripe is a phenomenon in which toner adheres to the surface of the developing sleeve along the rotation direction of the developing sleeve.
○ (good): Toner adhesion and vertical stripes were not observed on the surface of the developing sleeve.
X (bad): Toner adhesion and vertical stripes were observed on the surface of the developing sleeve.

The evaluation criteria for the anti-drum adhesion were as follows. The dash mark is an image defect that can be caused by the toner adhering to the surface of the photosensitive drum.
○ (Good): The number of dash marks was 0 or more and 1 or less.
X (bad): There were two or more dash marks.

Further, after the above-described image formation, the two-component developer was taken out from the evaluation machine, the toner was sucked and removed from the two-component developer using a 795 mesh net, and the carrier was extracted. Subsequently, the obtained carrier was placed on a combustion board of a solid carbon analyzer (“EMIA-110” manufactured by Horiba, Ltd.) and burned at 1400 ° C. The amount of carbon adhering to the carrier (ratio of the amount of carbon to the total mass of the carrier) was calculated by analyzing the gas generated during combustion using an infrared analyzer of a solid carbon analyzer. From the measurement result of the carbon content, the spent resistance of the sample (toner) was evaluated according to the following criteria. The carbon attached to the carrier is considered to be derived from the binder resin contained in the toner particles. For this reason, the amount of carbon obtained as described above is an indicator of the spent amount.
○ (Good): Carbon content was 0.2% by mass or less.
X (Poor): Carbon amount exceeded 0.2% by mass.

(Charging characteristics: Charging and charging stability)
A developer carrier (a carrier for a multifunction machine “TASKalfa7551ci” manufactured by Kyocera Document Solutions Co., Ltd.) and a sample (toner) are mixed for 30 minutes using a ball mill, and two-component development with a toner content of 10% by mass is performed. An agent was prepared. Then, after forming an image using the obtained two-component developer, the charge amount of the toner was measured, and the chargeability and charge stability of the toner were evaluated. As the evaluation machine, “TASKAlfa 7551ci” manufactured by Kyocera Document Solutions Co., Ltd. was used. The two-component developer prepared as described above was put into a developing device of an evaluation machine, and a sample (replenishment toner) was put into a toner container of the evaluation machine.

  Using the evaluation machine, continuous printing at a printing rate of 10% was performed on 100,000 sheets of paper (A4 size printing paper) in an environment of normal temperature and normal humidity (temperature 25 ° C., humidity 50% RH). Thereafter, the developer was taken out from the developing device. The toner charge amount of the removed developer was measured. For the measurement of the charge amount, a Q / m meter (“MODEL 210HS” manufactured by TREK) was used. Specifically, the toner in the sample 0.10 g (± 0.01 g) is sucked using the suction part of the Q / m meter, and the charge amount is determined based on the amount of the sucked toner and the display of the Q / m meter. Calculated (measurement number n = 3).

The average value of the calculated charge amount was defined as the average charge amount. Then, the chargeability of the sample (toner) was evaluated from the calculated average charge amount of the toner according to the following criteria.
○ (Good): The average charge amount was 20 μC / g or more and 30 μC / g or less.
X (Poor): Average charge amount was less than 20 μC / g.

Of the calculated n number of charge amounts, the difference obtained by subtracting the minimum value of the charge amount from the maximum value of the charge amount was calculated. Then, the charging stability of the sample (toner) was evaluated from the calculated difference in toner charge amount according to the following criteria.
A (very good): The difference in charge amount was less than 5 μC / g.
○ (good): The difference in charge amount was 5 μC / g or more and less than 10 μC / g.
X (Poor): Difference in charge amount was 10 μC / g or more.

(Developability)
A developer carrier (a carrier for a multifunction machine “TASKalfa7551ci” manufactured by Kyocera Document Solutions Co., Ltd.) and a sample (toner) are mixed for 30 minutes using a ball mill, and two-component development with a toner content of 10% by mass is performed. An agent was prepared. Then, an image was formed using the obtained two-component developer, and the developability of the toner was evaluated. As the evaluation machine, “TASKAlfa 7551ci” manufactured by Kyocera Document Solutions Co., Ltd. was used. The two-component developer prepared as described above was put into a developing device of an evaluation machine, and a sample (replenishment toner) was put into a toner container of the evaluation machine.

Using the evaluation machine, continuous printing at a printing rate of 10% was performed on 100,000 sheets of paper (A4 size printing paper) in an environment of normal temperature and normal humidity (temperature 25 ° C., humidity 50% RH). Thereafter, an image for evaluation including a solid portion was formed on paper under a normal temperature and humidity environment. The image density (ID) of the solid portion in the evaluation image was measured using a reflection densitometer (“RD914” manufactured by Sakata Inx Engineering Co., Ltd.). The developability of the sample (toner) was evaluated from the measured image density (ID) according to the following criteria.
○ (Good): Image density was 1.3 or more.
X (Poor): The image density was less than 1.3.

(Comprehensive evaluation)
From the evaluation results of developability and storage stability, the toner was comprehensively evaluated according to the following criteria.
○ (good): The evaluation results of developability and storage stability were all good (good).
X (bad): Among the evaluation results of developability and storage stability, there was at least one x (bad).

[Evaluation results]
Toners A-1 to A-3, Toners B-1 to B-3, Toners C-1 to C-3 and Toners D-1 to D-3 (Toners of Examples 1 to 6 and Comparative Examples 1 to 6) Table 2 shows the evaluation results (storability, developability, charging characteristics, and adhesion resistance).

  Toner A-2, Toners B-1 to B-3 and Toners D-1 to D-2 (Toners according to Examples 1 to 6) were toners having the configuration (1). Specifically, the toners according to Examples 1 to 6 contained a quaternary ammonium salt. This quaternary ammonium salt had a hydrophobic group and a quaternary ammonium group as a hydrophilic group. In the toners according to Examples 1 to 6, the ratio A was 10 ppm to 200 ppm, and the ratio B was 5 ppm to 120 ppm.

  Toner A-1, Toner A-3, Toners C-1 to C-3 and Toner D-3 (Toners according to Comparative Examples 1 to 6) were toners having no configuration (1). Specifically, in the toner according to Comparative Examples 1 and 2 and the toner according to Comparative Examples 5 to 6, the ratio A was not 10 ppm to 200 ppm, and the ratio B was not 5 ppm to 120 ppm. In the toners C-1 to C-2 (toners according to Comparative Examples 3 to 4), the ratio B was not 5 ppm or more and 120 ppm or less.

  The toners according to Examples 1 to 6 were all evaluated as good (good). The toners according to Comparative Examples 1 to 6 were all evaluated as x (bad). It has been shown that the toners according to Examples 1 to 6 can achieve both storability and developability as compared with the toners according to Comparative Examples 1 to 6.

  Further, the toners according to Examples 1 to 6 have evaluation results of charging characteristics (chargeability and charging stability) and adhesion resistance (sleeve resistance, drum resistance, and spent resistance) ◎ (very good) ) Or ○ (good). The toners according to Examples 1 to 11 were excellent in charging characteristics and adhesion resistance.

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

Claims (2)

A positively chargeable electrostatic latent image developing toner having a plurality of toner particles,
The toner particles include a toner core and a shell layer that covers a surface of the toner core;
The shell layer is made of a copolymer of styrene and butyl acrylate,
The toner particles contain a quaternary ammonium salt;
The quaternary ammonium salt has a hydrophobic group and a quaternary ammonium group as a hydrophilic group,
The ratio of the quaternary ammonium salt in the surface layer of the toner particles is 10 ppm or more and 200 ppm or less as measured by time-of-flight secondary ion mass spectrometry (TOF-SIMS),
The ratio of said quaternary ammonium salt in the whole toner particles, Ri 5ppm above 120ppm der less as measured by gas chromatography-mass spectrometry (GCMS),
The toner core includes a binder resin made of a polyester resin,
The toner for developing an electrostatic latent image, wherein the quaternary ammonium salt is dodecyltrimethylammonium chloride . The electrostatic latent image developing toner according to claim 1, wherein the polyester resin includes a repeating unit derived from propanediol, a repeating unit derived from terephthalic acid, and a repeating unit derived from trimellitic anhydride.