Toner, process cartridge, and electrophotographic image forming apparatus

Abstract

To provide a toner that suppresses fogging and developing roller filming, and enables the formation of high-quality images even in faster and longer-lasting electrophotographic image forming apparatuses. [Solution] A toner having toner particles and an external additive, (1) The toner particles contain a binder resin, a positive charge control agent, and an ester compound, The binder resin contains a resin having a vinyl polymer portion and a polyester portion, the polyester portion contains alkenyl succinic acid units, and the alkenyl succinic acid units have alkenyl groups having 10 to 22 carbon atoms. The positive charge control agent is a nigrosine compound, The ester compound is an ester of pentaerythritol or dipentaerythritol with a saturated or unsaturated aliphatic monocarboxylic acid having 10 to 22 carbon atoms. (2) The external additive contains silicone resin particles, It is characterized by the following:

Description

Technical Field

[0001] The present disclosure relates to a toner, a process cartridge, and an electrophotographic image forming apparatus used in an image forming method such as an electrophotographic method.

Background Art

[0002] In an electrophotographic image forming apparatus such as a printer or a copier, toner is used to develop a latent image on a photoreceptor. Usually, toner has a configuration in which various organic or inorganic fine particles are externally added to toner particles in order to impart various properties such as necessary charging characteristics and fluidity, and such fine particles are referred to as external additives. An electrophotographic image forming apparatus has various electrophotographic members such as a photoreceptor (electrostatic latent image carrier), a developing roller (toner carrier), and a toner regulating member, and in the process of image formation, toner is repeatedly rubbed by these members. Toner deteriorates by being rubbed, which is partly because the external additive is buried in the toner particles or transferred to the electrophotographic members by rubbing, and is gradually lost from the surface of the toner particles. When the deterioration of the toner progresses, an image defect called fog may occur due to a decrease in the charging property of the toner. In addition, since the toner is likely to adhere to the electrophotographic members, it may cause a defect such as developing roller filming. Developing roller filming is a phenomenon in which the surface of the developing roller is covered with a fused product of deteriorated toner, and significant image defects such as vertical streaks occur in the fused portion. As a countermeasure against such toner deterioration, for example, Patent Document 1 and Patent Document 2 show examples of using silicone resin particles as an external additive. Compared with inorganic particles such as silica generally used as an external additive, silicone resin particles are soft and elastic particles, so they are difficult to be buried in toner particles, and toner deterioration is likely to be suppressed.

Prior Art Documents

Patent Documents

[0003] [Patent Document 1] Japanese Patent Publication No. 2013-140235 [Patent Document 2] Japanese Patent Publication No. 2016-126140 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, in recent years, electrophotographic image forming apparatuses have been required to be even faster and have longer lifespans, and the friction load on the toner tends to increase. According to the inventors' research, in such harsh operating environments, toners using silicone resin particles as an external additive sometimes resulted in fogging and developing roller filming. In view of these problems, the objective of the present invention is to provide a toner that suppresses the occurrence of fogging and developing roller filming, and that enables the formation of high-quality images even in faster and longer-lasting electrophotographic image forming apparatuses. [Means for solving the problem]

[0005] The inventors diligently studied to solve the above problems. As a result, they found that the above problems can be solved with the following configuration. In other words, the present invention is a toner having toner particles and an external additive, (1) The toner particles contain a binder resin, a positive charge control agent, and an ester compound, The binder resin contains a resin having a vinyl polymer portion and a polyester portion, the polyester portion contains alkenyl succinic acid units, and the alkenyl succinic acid units have alkenyl groups having 10 to 22 carbon atoms. The positive charge control agent is a nigrosine compound, The ester compound is an ester of pentaerythritol or dipentaerythritol with a saturated or unsaturated aliphatic monocarboxylic acid having 10 to 22 carbon atoms. (2) The external additive contains silicone resin particles, This toner has the following characteristics. Furthermore, the present invention relates to a process cartridge having toner, a developing roller that carries the toner, and a toner restricting member that contacts the developing roller and restricts the toner carried on the developing roller, and is configured to be detachably attached to the main body of an electrophotographic image forming apparatus, wherein the toner is the toner configured as described above. Furthermore, the present invention relates to an electrophotographic image forming apparatus comprising toner, a photoreceptor on which an electrostatic latent image is formed, a developing roller that carries the toner and develops the electrostatic latent image into a toner image, and a toner regulating member that contacts the developing roller and regulates the toner carried on the developing roller, wherein the toner is the toner having the above configuration. [Effects of the Invention]

[0006] The toner of the present invention suppresses fogging and developing roller filming, enabling the formation of high-quality images even in faster and longer-lasting electrophotographic image forming apparatuses. [Brief explanation of the drawing]

[0007] [Figure 1] This diagram shows a simplified representation of the configuration around the developing roller in a process cartridge filled with the toner of the present invention. [Modes for carrying out the invention]

[0008] The present invention will be described in detail below, but is not limited to this description.

[0009] In this disclosure, unless otherwise specified, the expressions "greater than or equal to XX and less than or equal to XX" or "XX to XX" refer to a numerical range that includes the lower and upper limits.

[0010] [Features of the present invention] The present invention relates to a toner having toner particles and an external additive, (1) The toner particles contain a binder resin, a positive charge control agent, and an ester compound, The binder resin contains a resin having a vinyl polymer portion and a polyester portion, the polyester portion contains alkenyl succinic acid units, and the alkenyl succinic acid units have alkenyl groups having 10 to 22 carbon atoms. The positive charge control agent is a nigrosine compound, The ester compound is an ester of pentaerythritol or dipentaerythritol with a saturated or unsaturated aliphatic monocarboxylic acid having 10 to 22 carbon atoms. (2) The external additive contains silicone resin particles, It is characterized by the following:

[0011] The inventors have found that by using the above configuration, the occurrence of fogging and developing roller filming can be suppressed throughout the lifespan of the electrophotographic image forming apparatus, enabling the formation of high-quality images even in faster and longer-lasting electrophotographic image forming apparatuses. Although the detailed reasons for this are unclear, the inventors have hypothesized the following.

[0012] Figure 1 is a simplified diagram illustrating the configuration around the developing roller in a process cartridge equipped with toner, a developing roller, a toner regulating member, a photoreceptor, and a toner supply roller. During the image formation process, the toner 2 filled in the toner container 1 is supplied onto the developing roller 4 by the toner supply roller 3, and then a uniform toner coating layer is formed on the developing roller 4 by the toner regulating member 5. At this time, the toner is subjected to strong friction at the contact point between the developing roller 4 and the toner regulating member 5. The toner coating layer is carried to the contact point with the photoreceptor 6, and some of the toner is transferred onto the photoreceptor 6 by development, while the undeveloped toner passes through the blowout prevention member 7 and is then peeled off from the developing roller 4 by the toner supply roller 3.

[0013] In demanding environments requiring higher speeds and longer lifespans, the toner is subjected to repeated strong friction as it passes over the contact points between the developing roller and the toner regulating member multiple times. As a result, the external additives gradually migrate from the toner to the developing roller, causing the toner to deteriorate. In deteriorated toner, the surface of the toner particles becomes exposed, and it is thought that some of the toner particles peel off from this surface, becoming fragments. These toner particle fragments can easily fuse to the developing roller, causing filming. Among the components contained in the toner particles, the release agent component in particular has a relatively low molecular weight and is a component that easily fuses.

[0014] In the configuration of the present invention, it is presumed that fogging and developing roller filming are suppressed by the interaction of the following components (i) to (v). Silicone resin particles...(i) Nigrosine compounds...(ii) Vinyl polymer portion in the binder resin... (iii) Alkenyl succinic acid units having an alkenyl group with 10 to 22 carbon atoms contained in the polyester portion of the binder resin...(iv) Esters of pentaerythritol or dipentaerythritol with saturated or unsaturated aliphatic monocarboxylic acids having 10 to 22 carbon atoms...(v)

[0015] The external additive, silicone resin particles (i), gradually migrate from the toner to the developing roller through repeated friction. The nigrosine compound (ii) is contained in the toner particle fragments generated by degradation. Since the silicone resin particles tend to be charged towards the negative side and the nigrosine compound towards the positive side, the positively charged toner particle fragments become coated with the negatively charged silicone resin particles on the developing roller, making them easily detachable from the developing roller and suppressing developing roller filming. Furthermore, the toner particle fragments coated with silicone resin particles have a moderate charge property, making them less likely to cause fogging. These toner particle fragments are then coated onto the developing roller again and developed, after which they are discharged from the toner container system.

[0016] On the other hand, (v) is a release agent component, and among the components that make up toner particles, it has a relatively low molecular weight and is not easily charged. Therefore, (v) alone is likely to fuse to the developing roller and cannot be expected to have the effect of coating the silicone resin particles (i) charged on the negative, making it a component that is likely to cause developing roller filming. However, (v), being a long-chain fatty acid ester compound, has high compatibility with the alkenyl succinic acid unit of (iv), which also has a long-chain structure. On the other hand, the nigrosine compound (ii) has a planar structure with linked aromatic rings and has high affinity with the vinyl polymer portion (iii). The vinyl polymer portion of (iii) is an element that makes up the binding resin together with the alkenyl succinic acid unit of (iv), so as a result (ii), (iii), (iv), and (v) become compatible within the toner particles. As a result, it is possible to suppress the fusion of the release agent component (v) to the developing roller by itself. It is presumed that the release agent components of nigrosine compounds (ii) and (v) work together to coat the charged silicone resin particles on the negative, making it easy to peel off from the developing roller.

[0017] The following describes preferred embodiments of the toner of the present invention. However, the preferred embodiments are not limited to those described herein.

[0018] 〔toner〕 The following sections describe the individual components that make up the toner and the manufacturing method for the toner.

[0019] <Toner particles> The toner particles according to the present invention contain a binder resin, a positive charge control agent, and an ester compound.

[0020] The binder resin content is preferably 50% by mass or more relative to the total amount of resin components in the toner particles.

[0021] The binder resin contains a resin having a vinyl polymer portion and a polyester portion, the polyester portion containing alkenyl succinic acid units, and the alkenyl succinic acid units having alkenyl groups with 10 to 22 carbon atoms.

[0022] Examples of chemical structures constituting the vinyl polymer portion include those made of styrene-acrylic copolymers. Examples of styrene-acrylic copolymers include polymers made of the following monofunctional polymerizable monomers or polyfunctional polymerizable monomers, copolymers obtained by combining two or more of these, and mixtures thereof.

[0023] Examples of monofunctional polymerizable monomers include the following:

[0024] Styrene; α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, and other styrene derivatives; methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate Acrylic polymerizable monomers such as methyl methacrylate and 2-benzoyloxyethyl acrylate; methacrylic polymerizable monomers such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-nonyl methacrylate, diethyl phosphate ethyl methacrylate, and dibutyl phosphate ethyl methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, and vinyl formate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and vinyl isopropyl ketone.

[0025] Examples of polyfunctional polymerizable monomers include the following:

[0026] Diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, 2,2'-bis(4-(acryloxydiethoxy)phenyl)propane, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol Dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2'-bis(4-(methacryloxy / diethoxy)phenyl)propane, 2,2'-bis(4-(methacryloxy / polyethoxy)phenyl)propane, trimethylolpropane trimethacrylate, tetramethylolmethane tetramethacrylate, divinylbenzene, divinylnaphthalene, divinyl ether, etc.

[0027] Examples of chemical structures constituting the polyester portion include those consisting of condensed polymers of carboxylic acid and alcohol components, as listed below.

[0028] The carboxylic acid component may contain alkenyl succinic acid having an alkenyl group with 10 to 22 carbon atoms, and may also contain terephthalic acid, isophthalic acid, phthalic acid, fumaric acid, maleic acid, cyclohexanedicarboxylic acid, and trimellitic acid as needed. The alcohol component may include bisphenol A, hydrogenated bisphenol, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, glycerin, trimethylolpropane, and pentaerythritol.

[0029] Furthermore, the polyester resin may be a polyester resin containing urea groups. It is preferable that the carboxyl groups at the ends of the polyester resin are not capped.

[0030] In a resin having a vinyl polymer portion and a polyester portion, the content of the polyester portion is, for example, 40% by mass or more and 90% by mass or less, preferably 50% by mass or more and 80% by mass or less.

[0031] There are no particular limitations on the method for hybridizing the vinyl polymer portion and the polyester portion, but examples include the following: a method in which monomer components that can react with both components are included in the vinyl polymer portion and / or the polyester portion, or a method in which the polyester portion is transesterified in a vinyl polymer portion containing ester-derived structural units. Examples of monomers that can react with both components include fumaric acid, acrylic acid, methacrylic acid, citraconic acid, maleic acid, and dimethyl fumarate.

[0032] The acid value of the polyester portion is preferably 4.0 mg KOH / g or more and 10.0 mg KOH / g or less.

[0033] Nigrosine compounds are used as positive charge control agents. They may also be used in combination with other positive charge control agents such as quaternary ammonium salts, guanidine compounds, and imidazole compounds, if necessary.

[0034] Ester compounds are components used as mold release agents and are esters of pentaerythritol or dipentaerythritol with saturated or unsaturated aliphatic monocarboxylic acids having 10 to 22 carbon atoms.

[0035] The content of the release agent is preferably 1.0 part by mass or more and 30.0 parts by mass or less per 100.0 parts by mass of the binder resin or polymerizable monomer that forms the binder resin.

[0036] The melting point of the release agent is preferably 30°C to 120°C, and more preferably 60°C to 100°C. By using a release agent exhibiting the above thermal properties, the release effect is efficiently achieved, and a wider fixing area is secured.

[0037] The toner particles may contain a colorant. Known pigments and dyes can be used as the colorant. Pigments are preferred as the colorant due to their excellent weather resistance.

[0038] Examples of cyanide-based colorants include copper phthalocyanine compounds and their derivatives, anthraquinone compounds, and basic dye lake compounds.

[0039] Specifically, the following are listed: CI Pigment Blue 1, 7, 15, 15:1, 15:2, 15:3, 15:4, 60, 62, and 66.

[0040] Examples of magenta-based colorants include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolon compounds, thioindigo compounds, and perylene compounds.

[0041] Specifically, the following are listed: CI Pigment Red 2, 3, 5, 6, 7, 23, 48:2, 48:3, 48:4, 57:1, 81:1, 122, 144, 146, 150, 166, 169, 177, 184, 185, 202, 206, 220, 221 and 254, and CI Pigment Violet 19.

[0042] Examples of yellow colorants include condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds.

[0043] Specifically, the following are listed: CI Pigment Yellow 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, 185, 191, and 194.

[0044] Examples of black colorants include carbon black and those colored black using the above-mentioned yellow, magenta, and cyan colorants.

[0045] These colorants can be used individually, in mixtures, or even in solid solutions.

[0046] It is preferable to use a coloring agent in an amount of 1.0 part by mass or more and 20.0 parts by mass or less per 100.0 parts by mass of the binder resin.

[0047] Toner can also be made into magnetic toner by incorporating a magnetic material. In this case, the magnetic material can also serve as a colorant.

[0048] Examples of magnetic materials include iron oxides such as magnetite, hematite, and ferrite; metals such as iron, cobalt, and nickel; and alloys and mixtures thereof of these metals with metals such as aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, and vanadium.

[0049] <External additives> The external additive according to the present invention contains silicone resin particles. The external additive is preferably particle-sized to be 1 / 10 or less of the number-average particle diameter of the toner particles, considering its durability when added to toner particles.

[0050] Silicone resin particles have a structure in which silicon atoms and oxygen atoms are alternately bonded, and preferably have a T3 unit structure represented by the following formula (2). R1 -SiO 3 / 2 ···(2) (In formula (2), R 1 represents an alkyl group or a phenyl group having 1 to 6 carbon atoms (preferably 1 to 4 carbon atoms, more preferably 1 or 2).)

[0051] The solid of the silicone resin particles 29 In the Si-NMR measurement, the ratio of the area of the peak derived from silicon having a T3 unit structure to the total area of the peaks derived from all silicon elements contained in the silicone resin particles is preferably 0.50 or more and 1.00 or less, more preferably 0.70 or more and 1.00 or less.

[0052] Within the above range, the silicone resin particles have appropriate hardness and elasticity, so that the particles are not easily crushed even in repeated rubbing, and it is easy to exhibit the effects of suppressing fogging and developing roller filming.

[0053] As the silicone resin particles, particles obtained by polymerizing an organosilicon compound having a structure represented by the following formula (3) are preferably used.

[0054] [Chemical formula] (In formula (3), R 2 , R 3 , R 4 and R 5 each independently represents an alkyl group having 1 to 6 carbon atoms (preferably 1 to 4 carbon atoms, more preferably 1 or 2), a phenyl group, or a reactive group (for example, a halogen atom, a hydroxy group, an acetoxy group, or an alkoxy group (preferably having 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms)).)

[0055] As the organosilicon compound to be polymerized, an organosilicon compound having 4 reactive groups in one molecule of formula (3) (tetrafunctional silane), in formula (3), R 2 is an alkyl group or a phenyl group, and 3 reactive groups (R3 , R 4 , R 5 ) organosilicon compounds (trifunctional silanes), R in equation (3) 2 , R 3 The group is an alkyl group or a phenyl group, and there are two reactive groups (R 4 , R 5 ) organosilicon compounds (difunctional silanes), R in equation (3) 2 , R 3 , R 4 is an alkyl group or a phenyl group, and one reactive group (R 5 ) organosilicon compounds (monofunctional silanes) You can use it.

[0056] In order to ensure that the ratio of the area of ​​peaks derived from silicon having a T3 unit structure to the total area of ​​peaks derived from all silicon elements contained in the silicone resin particles is between 0.50 and 1.00, it is preferable to use 50 mol% or more of a trifunctional silane as the organosilicon compound.

[0057] These reactive groups undergo hydrolysis, addition polymerization, and condensation polymerization to form a crosslinked structure, thereby obtaining silicone resin particles. For example, when a trifunctional silane is used as the organosilicon compound, R 3 , R 4 and R 5 Hydrolysis, addition polymerization, and condensation polymerization can be controlled by the reaction temperature, reaction time, reaction solvent, and pH.

[0058] Examples of tetrafunctional silanes include tetramethoxysilane, tetraethoxysilane, and tetraisocyanatesilane.

[0059] Trifunctional silanes include methyltrimethoxysilane, methyltriethoxysilane, methyldiethoxymethoxysilane, methylethoxydimethoxysilane, methyltrichlorosilane, methylmethoxydichlorosilane, methylethoxydichlorosilane, methyldimethoxychlorosilane, methylmethoxyethoxychlorosilane, methyldiethoxychlorosilane, methyltriacetoxysilane, methyldiacetoxymethoxysilane, methyldiacetoxyethoxysilane, methylacetoxydimethoxysilane, methylacetoxymethoxyethoxysilane, methylacetoxydiethoxysilane, methyltrihydroxysilane, methylmethoxydihydroxysilane, methylethoxydihydroxysilane, methyldimethoxyhydroxysilane, methylethoxymethoxyhydroxysilane, methyldiethoxyhydroxysilane, Examples include tyltrimethoxysilane, ethyltriethoxysilane, ethyltrichlorosilane, ethyltriacetoxysilane, ethyltrihydroxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyltrichlorosilane, propyltriacetoxysilane, propyltrihydroxysilane, butyltrimethoxysilane, butyltriethoxysilane, butyltrichlorosilane, butyltriacetoxysilane, butyltrihydroxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, hexyltrichlorosilane, hexyltriacetoxysilane, hexyltrihydroxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltrichlorosilane, phenyltriacetoxysilane, phenyltrihydroxysilane, and pentyltrimethoxysilane.

[0060] Examples of bifunctional silanes include di-tert-butyldichlorosilane, di-tert-butyldimethoxysilane, di-tert-butyldiethoxysilane, dibutyldichlorosilane, dibutyldimethoxysilane, dibutyldiethoxysilane, dichlorodecylmethylsilane, dimethoxydecylmethylsilane, diethoxydecylmethylsilane, dichlorodimethylsilane, dimethyldimethoxysilane, diethoxydimethylsilane, and diethyldimethoxysilane.

[0061] Examples of monofunctional silanes include t-butyldimethylchlorosilane, t-butyldimethylmethoxysilane, t-butyldimethylethoxysilane, t-butyldiphenylchlorosilane, t-butyldiphenylmethoxysilane, t-butyldiphenylethoxysilane, chlorodimethylphenylsilane, methoxydimethylphenylsilane, ethoxydimethylphenylsilane, chlorotrimethylsilane, trimethylmethoxysilane, ethoxytrimethylsilane, triethylmethoxysilane, triethylethoxysilane, tripropylmethoxysilane, tributylmethoxysilane, tripentylmethoxysilane, triphenylchlorosilane, triphenylmethoxysilane, and triphenylethoxysilane.

[0062] The silicone resin particles used in the present invention may be surface-treated to impart hydrophobicity.

[0063] Examples of hydrophobic treatment agents include chlorosilanes such as methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, t-butyldimethylchlorosilane, and vinyltrichlorosilane; Isobutyltrimethoxysilane, tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, o-methylphenyltrimethoxysilane, p-methylphenyltrimethoxysilane, n-butyltrimethoxysilane, i-butyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, dodecyltrimethoxysilane, tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, i-butyltriethoxysilane, decyltriethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, Alkoxysilanes such as γ-chloropropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-(2-aminoethyl)aminopropyltrimethoxysilane, and γ-(2-aminoethyl)aminopropylmethyldimethoxysilane; Silazanes such as hexamethyldisilazane, hexaethyldisilazane, hexapropyldisilazane, hexabutyldisilazane, hexapentyldisilazane, hexahexyldisilazane, hexacyclohexyldisilazane, hexaphenyldisilazane, divinyltetramethyldisilazane, and dimethyltetravinyldisilazane; Examples of siloxanes include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, hexamethyldisiloxane, and octamethyltrisiloxane.

[0064] The silicone resin particles used in the present invention preferably have a toluene-soluble content of 0.2% by mass or more and 5.0% by mass or less. Within this range, an appropriate amount of toluene-soluble content seeps out onto the surface of the developing roller, reducing the adhesion of toner particles to the developing roller, thus making it easier to obtain the effect of suppressing developing roller filming.

[0065] The toluene-soluble portion is preferably such that its weight-average molecular weight in polystyrene terms, as determined by GPC measurement, is between 1,000 and 10,000. Within this range, the toluene-soluble portion does not soak into the developing roller, and the viscosity of the toluene-soluble portion is not too high, thus making it easier to reduce the adhesion of toner particles to the developing roller.

[0066] To impart toluene-soluble components, a silane compound of a desired molecular weight with low reactivity can be added during the manufacturing process. Examples of silane compounds include silicone oils such as dimethyl silicone oil, methyl hydrogen silicone oil, methylphenyl silicone oil, alkyl-modified silicone oil, chloroalkyl-modified silicone oil, chlorophenyl-modified silicone oil, fatty acid-modified silicone oil, polyether-modified silicone oil, alkoxy-modified silicone oil, carbinol-modified silicone oil, amino-modified silicone oil, fluorine-modified silicone oil, and terminally reactive silicone oil.

[0067] The external additive preferably contains alumina particles in addition to silicone resin particles. Since the silicone resin particles become more easily charged to the negative through charge exchange with the alumina particles, the effect of clinging to toner particle fragments and making them easier to peel off from the developing roller is more readily obtained. From the viewpoint of an appropriate balance between positive and negative, the mass ratio of silicone resin particles to alumina particles is preferably 30:70 to 70:30.

[0068] Furthermore, it is preferable that the mass ratio of silicone resin particles to alumina particles in the toner (silicone resin particle content:alumina particle content) be 30:70 to 70:30. Since the silicone resin particles become more easily negatively charged through charge exchange with the alumina particles, the effect of clinging to toner particle fragments and making them easier to peel off from the developing roller is more easily obtained.

[0069] Furthermore, when the number-average particle diameter of the silicone resin particles is A (nm) and the number-average particle diameter of the alumina particles is B (nm), it is preferable that A and B satisfy the following formula (1). 0.05 ≤ A / B < 1.00 ···(1)

[0070] Within the above range, since the silicone resin particles are smaller than the alumina particles, they adhere more easily to toner particle fragments, making it easier to suppress developing roller filming.

[0071] Furthermore, various other organic or inorganic fine powders can be used as external additives as needed. Examples of other organic or inorganic fine powders include the following: (1) Fluidity imparters: Silica, titanium dioxide, carbon black, and carbon fluoride. (2) Abrasives: Metal oxides (e.g., strontium titanate, cerium oxide, magnesium oxide, chromium oxide), nitrides (e.g., silicon nitride), carbides (e.g., silicon carbide), metal salts (e.g., calcium sulfate, barium sulfate, calcium carbonate). (3) Lubricants: Fluorine-based resin powder (e.g., vinylidene fluoride, polytetrafluoroethylene), fatty acid metal salts (e.g., zinc stearate, calcium stearate). (4) Charge controllable particles: metal oxides (e.g., tin oxide, titanium oxide, zinc oxide, silica), carbon black, hydrotalcite.

[0072] The organic or inorganic fine powder may be hydrophobicized on its surface to improve the fluidity of the toner and to ensure uniform charging of the toner particles. Examples of treatment agents for hydrophobicizing the organic or inorganic fine powder include unmodified silicone varnish, various modified silicone varnishes, unmodified silicone oil, various modified silicone oils, silane compounds, silane coupling agents, other organosilicon compounds, and organotitanium compounds. These treatment agents may be used alone or in combination.

[0073] [Toner manufacturing method] The following describes one example of a method for obtaining the toner particles mentioned above, but it is not limited to this method.

[0074] The method for producing toner particles is not particularly limited, and methods such as suspension polymerization, dissolution-suspension, emulsification-coagulation, and pulverization can be used. As an example, a method for obtaining toner particles by pulverization is described below.

[0075] <Raw material mixing process> In the raw material mixing process, predetermined amounts of materials constituting toner particles, such as binder resin, positive charge control agent, ester compound, wax, and other components such as colorants as needed, are weighed, blended, and mixed. Two or more resins with different molecular weights may be used in combination as the binder resin. Examples of mixing equipment include double-con mixers, V-type mixers, drum-type mixers, super mixers, Henschel mixers, Nauta mixers, and Mechanohybrid (manufactured by Nippon Coke Industries Co., Ltd.).

[0076] <Melting and mixing process> Next, the mixed materials are melt-kneaded to disperse wax and other substances into the binder resin. In the melt-kneading process, batch-type kneaders such as pressure kneaders and Banbury mixers, or continuous kneaders can be used, and single-screw or twin-screw extruders are the mainstream due to their advantage of being able to produce continuously. Examples include the KTK twin-screw extruder (manufactured by Kobe Steel, Ltd.), the TEM twin-screw extruder (manufactured by Toshiba Machine Co., Ltd.), the PCM kneader (manufactured by Ikegai Iron Works, Ltd.), the twin-screw extruder (manufactured by KCK Co., Ltd.), the Co-kneader (manufactured by Buss Co., Ltd.), and the Needex (manufactured by Nippon Coke Industries, Ltd.). Furthermore, the resin composition obtained by melt-kneading may be rolled with two rolls or the like and cooled with water in a cooling process.

[0077] In the melt-mixing process, it is preferable to use a twin-screw extruder. By controlling the mixing temperature and screw rotation speed during the melt-mixing process, it is possible to control the dispersion state of the crystalline resin and amorphous resin, as well as the average number diameter of the domains.

[0078] The mixing temperature is preferably 110 to 140°C, more preferably 115 to 130°C. The screw rotation speed during mixing is not particularly limited and can be appropriately changed depending on the apparatus, but for example, 1000 to 1500 rpm is preferred.

[0079] <Cooling process> The means of the cooling process are not particularly limited. Examples include rolling the kneaded resin composition with twin-screw rollers or a drum and then cooling it with a steel belt cooler (manufactured by Nippon Steel Conveyor Co., Ltd.), or rolling while cooling with a drum equipped with press rollers and an internal cooling mechanism, such as a belt drum flaker (manufactured by Nippon Coke Co., Ltd.). In the cooling process, rolling while cooling with a belt drum flaker is preferred.

[0080] <Grinding process> Next, the cooled resin composition is pulverized to the desired particle size in a pulverization process. In the pulverization process, the material is coarsely pulverized using a pulverizer such as a crusher, hammer mill, or feather mill, and then further finely pulverized using a fine pulverizer such as a Kryptron system (manufactured by Kawasaki Heavy Industries), Super Rotor (manufactured by Nisshin Engineering Co., Ltd.), Turbo Mill (manufactured by Turbo Industries Co., Ltd.), or an air jet type pulverizer.

[0081] <Classification process> Subsequently, the particles are classified as needed using an inertial classification system such as an elbow jet (manufactured by Nippon Steel Mining Co., Ltd.), a centrifugal classification system such as Turboplex (manufactured by Hosokawa Micron Corporation), a TSP separator (manufactured by Hosokawa Micron Corporation), a Faculty (manufactured by Hosokawa Micron Corporation), a multi-segment classifier utilizing the Coanda effect, a wind classifier, or a sieve classifier to obtain toner particles.

[0082] <External addition process> Toner is obtained by externally adding silicone resin particles as an external additive, and, if necessary, alumina, and various other organic or inorganic fine powders, to the surface of toner particles.

[0083] Methods for adding external additives include mixing a predetermined amount of classified toner with various known external additives, and then stirring and mixing them using a mixing device such as a double-con mixer, V-type mixer, drum-type mixer, super mixer, Henschel mixer, Nauta mixer, Mechanohybrid (manufactured by Nippon Coke Industries Co., Ltd.), or Novilta (manufactured by Hosokawa Micron Corporation) as the external additive machine.

[0084] When adding an external additive to toner particles, the external mixing time is preferably 3 to 20 minutes. Furthermore, the amount of silicone resin particles added is preferably 0.1 parts by mass or more and 5.0 parts by mass or less per 100.0 parts by mass of toner particles.

[0085] [Process cartridges, electrophotographic image forming apparatus] The toner with the above configuration of the present invention can be suitably used in an electrophotographic image forming apparatus that has a process cartridge detachably attached to the main body of the electrophotographic image forming apparatus, which has a developing roller that carries toner and a toner restricting member that contacts the developing roller and restricts the toner carried on the developing roller, as described in Figure 1, and a photoreceptor on which an electrostatic latent image is formed, and each component related to the process cartridge.

[0086] [Methods for measuring various physical properties] The measurement methods for various physical properties according to the present invention are described below.

[0087] <Separation of binder resin and ester compounds from toner> Separation of binder resins and ester compounds from toner is possible by known methods, one example of which is shown below.

[0088] Gradient polymer elution chromatography (GPEC) is used to separate the binder resin from the ester compound. This analysis allows for separation based on the polarity of the compound, regardless of its molecular weight.

[0089] First, the toner was dissolved in chloroform. The sample was adjusted to a sample concentration of 0.1% by mass using chloroform, and the solution was filtered through a 0.45 μm PTFE filter to remove insoluble matter before being used for measurement. The GPEC analysis conditions are shown below. Equipment: UlTIMATE3000 (manufactured by Thermo Fisher Scientific) Mobile phase: A. Chloroform (HPLC), B. Acetonitrile (HPLC) Gradient: 2 min (A / B = 0 / 100) → 25 min (A / B = 100 / 0) (Note: The gradient of the mobile phase change was made to be a straight line.) Flow rate: 1.0mL / min Injection: 0.1% by mass x 20μL Column: Tosoh TSKgel ODS (4.6mmφ x 150mm x 5μm) Column temperature: 40℃ Detector: Corona Charged Particle Detector (Corona-CAD) (manufactured by Thermo Fisher Scientific)

[0090] The time-intensity graph obtained from the measurement allows for the separation of the binder resin and ester compound as different peaks depending on their polarity. Subsequently, by repeating the above measurement and sampling at the time of the trough of each peak, it is possible to separate the binder resin and ester compound.

[0091] <Analysis of the binding resin> The binder resin in this invention is a resin having a vinyl polymer portion and a polyester portion. The composition of the binder resin is: 1 Analysis can be performed by 1H-NMR and reaction pyrolysis GC / MS.

[0092] · 1 H-NMR A solution of 10 mg of the binder resin separated using the aforementioned GPEC method, dissolved in deuterated chloroform, was used as the sample, and under the following conditions... 1 Perform 1H-NMR measurements. Measuring device: FT NMR device JNM-EX400 (manufactured by JEOL Ltd.) Measurement frequency: 400MHz Pulse condition: 5.0 μs Frequency range: 10500Hz Total number of times: 64 Measurement temperature: 23℃

[0093] 1 By analyzing the 1H-NMR chart, the composition ratio of each monomer unit constituting the vinyl polymer portion and the polyester portion can be obtained.

[0094] • Reaction pyrolysis GC / MS The alcohol units and carboxylic acid units constituting the polyester portion can be identified by selectively cleaving the ester bonds using reaction pyrolysis GC / MS analysis with tetramethylammonium hydroxide (hereinafter referred to as TMAH).

[0095] Reaction pyrolysis GC / MS analysis can be performed under the following conditions. Mass spectrometer: ThermoFisherScinetific ISQ GC system: ThermoFisher Scientific FocusGC Ion source temperature: 250℃ Ionization method: EI Mass range: 50-1000 m / z Column: HP-5MS [30m] Pyrolysis apparatus: JPS-700, manufactured by Nippon Analytical Industry Co., Ltd.

[0096] A small amount of the binder resin separated using the aforementioned GPEC method and 1 μL of TMAH are added to a pyrofoil heated to 590°C. By performing thermal decomposition GC-MS measurement of the prepared sample under the above conditions, peaks for the alcohol unit and carboxylic acid unit constituting the polyester portion are obtained. Due to the action of the methylating agent TMAH, the alcohol unit and carboxylic acid unit are detected as methylated products. By analyzing the obtained peaks, the structures of the alcohol unit and carboxylic acid unit constituting the polyester portion can be identified.

[0097] <Analysis of ester compounds> For the analysis of ester compounds, the ester compounds separated by GPEC are used as samples and analyzed using the reaction pyrolysis GC / MS method described above. By analyzing the resulting peaks, the structure of the ester compound can be identified.

[0098] <Procedure for separating external additives contained in toner> When separating inorganic additives such as alumina particles and silica particles, and silicone resin particles contained in toner, the difference in specific gravity is first used to separate the inorganic additives from the toner particles and silicone resin particles. Subsequently, the difference in particle size is used to separate the toner particles from the silicone resin particles.

[0099] In a separation procedure utilizing differences in specific gravity, inorganic external additives such as alumina particles and silica particles have a true specific gravity of 2.0 or higher, while toner particles and silicone resin particles have a true specific gravity of approximately 1.0 to 1.3. Therefore, the specific gravity of a saturated sucrose solution at 20°C is 1.33, which is used to separate them.

[0100] 100g of deionized water is mixed with 200g of sucrose, dissolved in a water bath, and then cooled to 20°C to obtain a saturated sucrose solution. 31g of the saturated sucrose solution and 6g of Contaminon N (a 10% aqueous solution of pH 7 neutral detergent for cleaning precision measuring instruments, consisting of a nonionic surfactant, anionic surfactant, and organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) are weighed into a centrifuge tube, and 1.0g of toner is added. The mixture is then shaken for 20 minutes at 350 reciprocations per minute using an Iwaki Sangyo Co., Ltd. "KM Shaker" (model: V.SX). After that, centrifugation is performed in a centrifuge at 3500 rpm for 30 minutes. In the tube after centrifugation, the upper layer contains toner particles and silicone resin particles with a low specific gravity, while the lower layer contains settled inorganic additives with a high specific gravity. After separating the upper and lower aqueous solutions, each solution is dried to obtain a mixture of toner particles and silicone resin particles from the upper layer and a mixture of inorganic external additives from the lower layer.

[0101] The mixture of toner particles and silicone resin particles obtained is dispersed in a mixed solution of 5 g of deionized water and 1 g of contaminon N. The solution is filtered through a PTFE filter with a pore size of 1 μm to separate the toner particles, and silicone resin particles are obtained from the filtrate.

[0102] <Identification of silicone resin particles, confirmation of T3 unit structure, and calculation of peak proportion of T3 unit structure in silicone resin particles> The composition and ratio of constituent compounds of silicone resin particles contained in toner are identified using NMR. If silicone resin particles are available individually, they can also be measured separately. When extracting from toner, as described in <Separation Procedure for External Additives in Toner>, the toner is dispersed in a dispersion medium, and the silicone resin particles are detached using a shaker or ultrasonic homogenizer. Separation can then be achieved using differences in specific gravity and particle size. For example, a solution of sucrose (manufactured by Kishida Chemical Co., Ltd.) dissolved in deionized water can be used as the dispersion medium. By changing the concentration of sucrose, the specific gravity can be adjusted to any range within which the external additives can be separated. During this process, the dispersion is cooled in an ice bath while applying ultrasound to prevent the dispersion from overheating.

[0103] <Solid 29 Si-NMR analysis procedure > The relative abundance of constituent compounds in silicone resin particles, 29 Measurement and calculation are performed using Si-NMR. Specifically, solid 29 Using Si-NMR analysis, we will confirm the T3 unit structure in silicone resin particles and calculate the ratio of the area of ​​peaks originating from silicon with a T3 unit structure to the total area of ​​peaks originating from all silicon elements. 29 In Si-NMR, peaks are detected in different shift regions depending on the structure of the functional groups bonded to Si in the constituent compounds of silicone resin particles. The structure of the functional groups in each peak is identified using standard samples. Furthermore, the abundance ratio of each constituent compound can be calculated from the obtained peak areas. The ratio of the peak area of ​​the T3 unit structure to the total peak area can be calculated. Solid 29 The measurement conditions for Si-NMR are as follows: Equipment: JNM-ECX5002 (JEOL RESONANCE) Temperature: room temperature Measurement method: DDMAS method 29 Si 45° Sample tube: Zirconia 3.2mmφ Sample: Filled in a test tube in powder form. Sample rotation speed: 10kHz Relaxation delay: 180s Scan: 2000

[0104] After the measurement, multiple silane components of the silicone resin particles with different substituents and bonding groups are separated into peaks for the following X1, X2, X3, and X4 structures by curve fitting, and the peak area of ​​each is calculated. Note that the X3 structure below is the T3 unit structure. X1 structure: (Ri)(Rj)(Rk)SiO 1 / 2 (A1) X2 structure: (Rg)(Rh)Si(O 1 / 2 )2(A2) X3 structure: RmSi(O 1 / 2 )3(A3) X4 structure: Si(O 1 / 2 )4(A4) (In formulas (A1) to (A4), Ri, Rj, Rk, Rg, Rh, and Rm each independently represent a hydrocarbon group having one or more carbon atoms, a halogen atom, etc., bonded to silicon.)

[0105] The peak area is calculated using the following procedure.

[0106] First, the obtained solid 29 A baseline is established for the Si-NMR spectrum. The baseline is defined as the line segment connecting the plot of intensity B1 at a chemical shift of +50 ppm and the plot of intensity B2 at a chemical shift of -150 ppm, where B1 is the arithmetic mean of intensity values ​​from chemical shift +40 ppm to +60 ppm, and B2 is the arithmetic mean of intensity values ​​from chemical shift -160 ppm to -140 ppm.

[0107] Peak X1, which originates from the X1 structure, has a chemical shift in the range of +10 ppm to +20 ppm. The area of ​​peak X1 in the chemical shift range of 0 ppm to +30 ppm is defined as S. x1 Let's assume that S x1 is a solid 29 This is the integral value of the region between the Si-NMR spectrum and the baseline.

[0108] Peak X2, which originates from the X2 structure, has a chemical shift in the range of -25 ppm to -15 ppm. The area of ​​peak X2 in the chemical shift range of -30 ppm to 0 ppm is defined as S. X2 Let's assume that S X2 is a solid 29 This is the integral value of the region between the Si-NMR spectrum and the baseline.

[0109] Peak X3, which originates from the X3 structure, has a chemical shift in the range of -70 ppm to -50 ppm. The area of ​​peak X3 in the chemical shift range of -80 ppm to -40 ppm is defined as S. X3 Let's assume that S X3 is a solid 29 This is the integral value of the region between the Si-NMR spectrum and the baseline.

[0110] Peak X4, which originates from the X4 structure, has a chemical shift in the range of -120 ppm to -90 ppm. The area of ​​peak X4 in the chemical shift range of -130 ppm to -80 ppm is defined as S. X4 Let's assume that S X4 is a solid 29 This is the integral value of the region between the Si-NMR spectrum and the baseline.

[0111] The obtained peak area S X1 S X2 S X3 and S X4 Using this method, the ratio of the area of ​​peaks derived from silicon with a T3 unit structure to the total area of ​​peaks derived from all silicon elements is calculated using the following formula. (Ratio of the area of ​​peaks derived from silicon with a T3 unit structure to the total area of ​​peaks derived from all silicon elements) = S X3 / (S X1 +S X2 +S X3 +S X4 )

[0112] <Quantitative determination of soluble content and molecular weight measurement of silicone resin particles> Silicone resin particles are separated from the toner by centrifugal separation using the aforementioned sucrose solution or the like as a dispersion medium. The mass of the obtained silicone resin particles is measured and recorded as the "initial mass." The particles are then dispersed in toluene at a ratio of 10 times their mass and allowed to stand for 24 hours before the toluene-insoluble components are separated by centrifugal separation. The obtained insoluble components are dried at 120°C for 2 hours, and their mass is measured and recorded as the "mass after toluene extraction." From the "initial mass" and the "mass after toluene extraction," the mass percentage of the total soluble content of the silicone resin particles in toluene is calculated using the following formula. Soluble content = {(Initial mass) - (Mass after toluene extraction)} / (Initial mass) × 100 [mass%]

[0113] On the other hand, the solution after separating the toluene-insoluble components by centrifugation is filtered through a solvent-resistant membrane filter "Maeshori Disc" (manufactured by Tosoh Corporation) with a pore diameter of 0.2 μm to obtain a sample solution, and GPC measurement is performed using this sample solution under the following conditions. Equipment: High-speed GPC system "HLC-8220GPC" [manufactured by Tosoh Corporation] Column: LF-604, double column [Manufactured by Showa Denko Corporation] Eluent: Toluene Flow rate: 0.6mL / min Oven temperature: 40℃ Sample injection volume: 0.020 mL

[0114] To calculate the molecular weight of the sample, a molecular weight calibration curve created using standard polystyrene resins (product names "TSK Standard Polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F-10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500", manufactured by Tosoh Co., Ltd.) is used to calculate the weight-average molecular weight.

[0115] <Mass ratio of silicone resin particles to alumina particles> The mass ratio of silicone resin particles to alumina particles contained in the toner was determined by X-ray fluorescence analysis, solid 29 Measurements are performed using Si-NMR analysis and GC / MS analysis. The procedure for cases where the external additive is silicone resin particles, alumina particles, and silica particles is described below.

[0116] (i) X-ray fluorescence analysis The measurement of X-ray fluorescence will conform to JIS K 0119-1969, specifically as follows: The measurement equipment will be the wavelength-dispersive X-ray fluorescence analyzer "Axios" (PANalytical) and the accompanying dedicated software "SuperQ ver.5.0L" (PANalytical) for setting measurement conditions and analyzing measurement data. Rh will be used as the anode of the X-ray tube, the measurement atmosphere will be vacuum, and the measurement diameter (collimator mask diameter) will be 27 mm. The measurement will be performed using the Omnian method to measure the range of elements from F to U. A proportional counter (PC) will be used to measure light elements, and a scintillation counter (SC) will be used to detect heavy elements. The acceleration voltage and current values ​​of the X-ray generator will be set to an output of 2.4 kW.

[0117] For the measurement sample, 4g of toner is placed in a dedicated aluminum ring for pressing and leveled. Using a tablet molding compressor "BRE-32" (manufactured by Maekawa Testing Machinery Co., Ltd.), it is pressurized at 20MPa for 60 seconds to form a pellet with a thickness of 2mm and a diameter of 39mm. The pellet formed under the above conditions is irradiated with X-rays, and the generated characteristic X-rays (fluorescent X-rays) are spectrally analyzed using a spectrometer. Next, the intensity of the fluorescent X-rays spectrally separated at angles corresponding to the wavelengths specific to each element contained in the sample is analyzed using the FP method (fundamental parameter method) to obtain the content ratio of each element contained in the toner as the analysis result. WS1 is defined as the ratio of the mass of silicon atoms to the total mass of silicon atoms and aluminum atoms in the toner, and WA1 is defined as the ratio of the mass of aluminum atoms. Here, WS1 is the ratio of the total mass of silicon atoms contained in the inorganic additive in the toner and the total mass of silicon atoms contained in the silicone resin particles.

[0118] Next, the inorganic external additive separated by the <Procedure for Separating External Additives Contained in Toner> is used as a sample, and its fluorescence X-rays are measured using the same procedure. WS2 is defined as the ratio of the mass of silicon atoms to the total mass of silicon and aluminum atoms in the inorganic external additive, and WA2 is defined as the ratio of the mass of aluminum atoms. Here, WS2 is the ratio of the mass of silicon atoms contained in the inorganic external additive in the toner.

[0119] WS1A is defined as the ratio of the mass of silicon atoms contained in the inorganic additive in the toner to the total mass of silicon atoms and aluminum atoms in the toner, and WS1B is defined as the ratio of the mass of silicon atoms contained in the silicone resin particles.

[0120] The following relationships (α) and (β) hold true for the values ​​of WS1, WA1, WS1A, WS1B, WS2, and WA2. WS1 / WA1=(WS1A+WS1B) / WA1...(α) WS2 / WA2 = WS1A / WA1···(β) From equations (α) and (β), the following equation (γ) can be derived. WS1B={(WS1 / WA1)-(WS2 / WA2)}×WA1...(γ)

[0121] The values ​​of WS1, WA1, WS2, and WA2 can be obtained by the aforementioned X-ray fluorescence measurement, and WS1B is calculated by substituting the obtained values ​​into equation (γ).

[0122] (ii) solid 29 Si-NMR analysis The silicone resin particles separated by the aforementioned <Separation procedure for external additives contained in toner> were used as the measurement sample. 29 Perform Si-NMR analysis. Solid 29 Si-NMR analysis is a solid-state analysis as described above. 29 The analysis was performed according to the Si-NMR analysis procedure, and the peak area S in the silicone resin particles was determined. X1 S X2 S X3and S X4 The peak area S obtained is obtained. X1 S X2 S X3 and S X4 Using this method, the ratio of the area of ​​the peaks originating from each silicon element with a specific structure to the total area of ​​the peaks originating from all silicon elements is calculated. The ratio of the area of ​​the peaks originating from silicon with the X1 structure is P X1 The proportion of the area of ​​the peak derived from silicon having an X2 structure is P. X2 The proportion of the area of ​​the peak derived from silicon having an X3 structure is defined as P X3 The proportion of the area of ​​the peak derived from silicon having an X4 structure is defined as P X4 Let's assume that.

[0123] (iii)GC / MS analysis 500 mg of silicone resin particles separated by the aforementioned <Separation Procedure for External Additives in Toner> are placed in a 300 ml flask, 250 mg of sulfuric acid is added, and the mixture is heated to 60°C and allowed to stand for 1 hour. Then, a mixture of 27 g of trimethyl orthoformate and 8.5 g of methanol is added to the flask and the mixture is reacted at reflux temperature (170°C) for 8 hours. This reaction cleaves the siloxane bonds in the silicone resin particles, yielding compounds Y1, Y2, Y3, and Y4 derived from the X1, X2, X3, and X4 structures in the silicone resin particles. Compound Y1:(Ri)(Rj)(Rk)SiOCH3(B1) Compound Y2:(Rg)(Rh)Si(OCH3)2(B2) Compound Y3: RmSi(OCH3)3(B3) Compound Y4:Si(OCH3)4(B4) (In formulas (B1) to (B4), Ri, Rj, Rk, Rg, Rh, and Rm each independently represent a hydrocarbon group having one or more carbon atoms, a halogen atom, etc., bonded to silicon.)

[0124] The solution obtained after the reaction is diluted with methanol and used as a sample for GC / MS analysis under the following conditions. Mass spectrometer: ThermoFisherScinetific ISQ GC system: ThermoFisher Scientific FocusGC Inlet temperature: 250℃ Injection volume: 1μL Column oven temperature: 40℃ → 300℃ (15℃ / min) Ion source temperature: 250℃ Ionization method: EI Mass range: 50-1000 m / z Column: HP-5MS [30m]

[0125] In the resulting chromatogram, peaks originating from compounds Y1, Y2, Y3, and Y4 are detected at different retention time positions. By examining the mass spectra of each peak, the molecular weights of compounds Y1, Y2, Y3, and Y4 can be determined. Based on the molecular weights of the obtained compounds Y1, Y2, Y3, and Y4, the molecular weights of structures X1, X2, X3, and X4 are calculated. The calculated molecular weight of structure X1 is then calculated as M X1 Let the molecular weight of the X2 structure be M X2 The molecular weight of the X3 structure is M X3 The molecular weight of the X4 structure is M X4 Let's assume that.

[0126] (iv) Calculation of the mass ratio of silicone resin particles to alumina particles Using the values ​​obtained in (i) to (iii), the content of silicone resin particles in the toner can be calculated. Similarly, the content of alumina particles in the toner can also be calculated. From the calculated content of silicone resin particles and alumina particles, the mass ratio of silicone resin particles to alumina particles in the external additive (the mass ratio of the content of silicone resin particles to the content of alumina particles in the toner (content of silicone resin particles: content of alumina particles)) is calculated. The calculation formula is as follows. Mass ratio of silicone resin particles to alumina particles in the external additive ={WS1B×(P X1×M X1 +P X2 ×M X2 +P X3 ×M X3 +P X4 ×M X4 )}:(WA1×51)

[0127] <Particle size of silicone resin particles and alumina particles> The number-average particle size of silicone resin particles and alumina particles can be measured using a scanning electron microscope (SEM). The toner containing the particles, or the inorganic additive separated by the aforementioned <Separation Procedure for Additives in Toner>, and the silicone resin particles are observed. The major axis of 100 randomly selected particles is measured in a field of view magnified up to 50,000 times to determine the number-average particle size. The observation magnification is adjusted as appropriate depending on the particle size. Details of the SEM observation conditions are as follows. Equipment: ULTRA PLUS manufactured by Carl Zeiss Microscopy Co., Ltd. Acceleration voltage: 1.0kV WD: 2.0mm Aperture Size: 30.0 μm Detection signal: EsB (Energy-selective backscattered electrons) EsB Grid: 800V Contrast: 63.0 ± 5.0% (reference value) Brightness: 38.0 ± 5.0% (reference value) Resolution: 1024 x 768 pixels Pre-treatment: Toner or particles are sprayed onto carbon tape (no vapor deposition is performed).

[0128] In toners where multiple types of particles are present, such as silicone resin particles and alumina particles, the elemental composition is confirmed and identified by superimposing elemental mapping images obtained by energy-dispersive X-ray spectroscopy (EDS) acquired with a scanning electron microscope (SEM) onto backscattered electron images. Similarly, in inorganic additives where multiple types of particles are present, such as silica particles and alumina particles, the elemental composition is confirmed by superimposing elemental mapping images obtained by energy-dispersive X-ray spectroscopy (EDS) acquired with a scanning electron microscope (SEM) onto backscattered electron images. Particles in which aluminum and oxygen are detected are identified as alumina particles and targeted for measurement. Details of the EDS conditions are as follows. Equipment (SEM): ULTRA PLUS, manufactured by Carl Zeiss Microscopy Co., Ltd. Equipment (EDS): NORANSystem 7, Ultra Dry EDS Detector, manufactured by Thermo Fisher Scientific Co., Ltd. Acceleration voltage: 5.0kV WD: 7.0mm Aperture Size: 30.0 μm Detection signal: SE2 (secondary electrons) Mode: Spectral Imaging Pre-treatment: Toner or particles are sprayed onto carbon tape (no vapor deposition is performed).

[0129] Furthermore, if silicone resin particles or alumina particles are available individually, the particles can also be measured separately.

[0130] <Method for measuring weight-average particle size (D4)> The weight-average particle size (D4) of toner or toner particles is calculated as follows:

[0131] The measuring device used is the "Coulter Counter Multisizer 3" (registered trademark, manufactured by Beckman Coulter, Inc.), a precision particle size distribution analyzer using the pore electrical resistance method equipped with a 100 μm aperture tube.

[0132] Setting measurement conditions and analyzing measurement data are performed using the included dedicated software, "Beckman Coulter Multisizer 3 Version 3.51" (manufactured by Beckman Coulter, Inc.). Measurements are performed using 25,000 effective measurement channels.

[0133] The electrolytic aqueous solution used for measurement is prepared by dissolving special grade sodium chloride in deionized water to a concentration of 1.0%, for example, "ISOTON II" (manufactured by Beckman Coulter, Inc.).

[0134] Before performing measurements and analysis, configure the dedicated software as follows.

[0135] In the dedicated software's "Change Standard Measurement Method (SOMME)" screen, set the total count in control mode to 50,000 particles, the number of measurements to 1, and the Kd value to the value obtained using "Standard Particle 10.0 μm" (manufactured by Beckman Coulter, Inc.). Press the "Measure Threshold / Noise Level Button" to automatically set the threshold and noise level. Also, set the current to 1,600 μA, the gain to 2, the electrolyte to ISOTON II, and check "Flush aperture tube after measurement".

[0136] In the dedicated software's "Pulse to Particle Size Conversion Settings" screen, set the bin spacing to logarithmic particle size, the particle size bins to 256 particle size bins, and the particle size range from 2 μm to 60 μm.

[0137] The specific measurement method is as follows: (1) Place 200.0 mL of electrolytic solution into a 250 mL round-bottom glass beaker specifically designed for the Multisizer 3, set it on the sample stand, and stir the mixture with the stirrer rod at 24 revolutions per second in a counterclockwise direction. Then, use the "Aperture Tube Flash" function of the dedicated software to remove any dirt and air bubbles from inside the aperture tube. (2) Place 30.0 mL of the electrolytic solution into a 100 mL flat-bottomed glass beaker. Add 0.3 mL of a diluted solution of "Contaminon N" (a 10% aqueous solution of a pH 7 neutral detergent for cleaning precision measuring instruments, consisting of a nonionic surfactant, anionic surfactant, and organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) diluted three times by mass with deionized water as a dispersant. (3) Prepare an "Ultrasonic Dispersion System Tetra150" (manufactured by Nikko Bios Co., Ltd.) with an electrical output of 120W, which incorporates two oscillators with an oscillation frequency of 50kHz, with their phases shifted by 180 degrees. Add 3.3L of deionized water to the water tank of the ultrasonic disperser, and add 2.0mL of Contaminon N to this water tank. (4) Place the beaker from (2) above into the beaker fixing hole of the ultrasonic disperser and operate the ultrasonic disperser. Then, adjust the height of the beaker so that the resonance state of the liquid surface of the electrolytic solution inside the beaker is maximized. (5) While irradiating the electrolytic aqueous solution in the beaker described in (4) above with ultrasound, add 10 mg of toner or the like to the electrolytic aqueous solution little by little and disperse it. Continue the ultrasonic dispersion treatment for another 60 seconds. During ultrasonic dispersion, adjust the water temperature in the tank as appropriate so that it is between 10°C and 40°C. (6) Using a pipette, add the electrolytic aqueous solution (5) containing the dispersed toner, etc., to the round-bottom beaker (1) placed in the sample stand, adjusting the concentration to 5%. Continue measuring until the number of particles reaches 50,000. (7) The measurement data is analyzed using the dedicated software provided with the device, and the weight-average particle size (D4) is calculated. Note that the "Average Diameter" on the "Analysis / Volume Statistics (Arithmetic Mean)" screen when the dedicated software is set to Graph / Volume % is the weight-average particle size (D4).

[0138] [Configurations included in embodiments of the present invention] This embodiment includes the following configuration. (Configuration 1) A toner having toner particles and an external additive, (1) The toner particles contain a binder resin, a positive charge control agent, and an ester compound, the binder resin contains a resin having a vinyl polymer part and a polyester part, the polyester part contains an alkenyl succinic acid unit, and the alkenyl succinic acid unit has an alkenyl group having 10 or more and 22 or less carbon atoms, the positive charge control agent is a nigrosine compound, the ester compound is an ester of pentaerythritol or dipentaerythritol and a saturated or unsaturated aliphatic monocarboxylic acid having 10 or more and 22 or less carbon atoms, (2) The external additive contains silicone resin particles, and is characterized by being a toner. (Configuration 2) The external additive further contains alumina particles, and the toner according to Configuration 1. (Configuration 3) The toner according to Configuration 2, wherein the mass ratio of the silicone resin particles to the alumina particles contained in the external additive is 30:70 to 70:30. (Configuration 4) When the number average particle diameter of the silicone resin particles is A (nm) and the number average particle diameter of the alumina particles is B (nm), the toner according to Configuration 2 or 3, wherein A and B satisfy the following formula (1). 0.05 ≦ A / B < 1.00 ···(1) (Configuration 5) The toner according to any one of Configurations 1 to 4, wherein the silicone resin particles have a T3 unit structure represented by the following formula (2). R 1 -SiO 3 / 2 ···(2) (In formula (2), R 1 represents an alkyl group having 1 or more and 6 or less carbon atoms or a phenyl group.) (Configuration 6) The toner according to any one of Configurations 1 to 5, wherein the silicone resin particles have a ratio of the area of the peak derived from silicon having a T3 unit structure to the total area of the peaks derived from all silicon elements of 0.50 or more and 1.00 or less in solid 29 Si-NMR measurement. (Configuration 7) The toner according to any one of Configurations 1 to 6, wherein the silicone resin particles have a soluble content in toluene of 0.2% by mass or more and 5.0% by mass or less. (Configuration 8) The toner according to Configuration 7, wherein the soluble content in toluene has a weight-average molecular weight in polystyrene terms determined by GPC measurement of 1,000 or more and 10,000 or less. (Configuration 9) The toner according to Configuration 2, wherein the mass ratio of the content of silicone resin particles to the content of alumina particles in the toner (content of silicone resin particles: content of alumina particles) is 30:70 to 70:30. (Configuration 10) A process cartridge comprising toner, a developing roller that carries the toner, and a toner restricting member that contacts the developing roller and restricts the toner carried on the developing roller, wherein the process cartridge is detachably attached to the main body of an electrophotographic image forming apparatus, and the toner is the toner described in any of Configurations 1 to 9. (Configuration 11) An electrophotographic image forming apparatus comprising toner, a photoreceptor on which an electrostatic latent image is formed, a developing roller that carries the toner and develops the electrostatic latent image into a toner image, and a toner regulating member that contacts the developing roller and regulates the toner carried on the developing roller, wherein the toner is the toner described in any of Configurations 1 to 9. [Examples]

[0139] The following are specific examples and comparative examples of the present invention, but this disclosure is not limited to the configurations described in the examples. Unless otherwise specified, all "parts" in the manufacturing examples and examples refer to mass.

[0140] <Example of synthesis of alkenyl succinate 1> 252 g of 1-octadecene and 98 g of maleic anhydride were placed in a flask and heated to 180°C under a nitrogen atmosphere. 8.8 g of di-tert-butyl peroxide was added over 2 hours, taking care to avoid exothermic reactions, to induce a radical copolymerization reaction. After maintaining the temperature at 180°C for 1 hour, the mixture was cooled to room temperature to obtain alkenyl succinic acid 1 having an alkenyl group with 18 carbon atoms.

[0141] <Examples of synthesis of alkenyl succinates 2-5> Alkenyl succinic acids 2-5 were obtained in the same manner as the synthesis example of alkenyl succinic acid 1, except that the raw materials used in the formulation were changed as shown in Table 1.

[0142] [Table 1]

[0143] <Example of synthesis of binder resin 1> In a reaction vessel, 900 g of 2,2-bis(4-hydroxyphenyl)propaneethylene oxide adduct, 160 g of terephthalic acid, 120 g of trimellitic acid, and 350 g of alkenyl succinic acid 1 were placed and mixed while heating to 135°C under a nitrogen atmosphere. To this mixture, a mixture of 420 g of styrene, 250 g of butyl acrylate, and 10 g of azobisisobutylnitrile was added dropwise over 1 hour. After the dropwise addition, the mixture was held at 135°C for 2 hours, then the temperature was raised to 230°C and the reaction was carried out for 4 hours to obtain a binder resin 1 having a vinyl polymer portion and a polyester portion.

[0144] <Examples of synthesis of binder resins 2-5> Binding resins 2 to 5 were obtained in the same manner as the synthesis example of binding resin 1, except that the raw materials used in the formulation were changed as shown in Table 2.

[0145] [Table 2]

[0146] <Example of synthesis of ester compound 1> 64 g of dipentaerythritol, 569 g of stearic acid, 6 g of p-toluenesulfonic acid, and 700 g of toluene were mixed and heated to 110°C to react. The resulting water was removed by azeotropic distillation with toluene. The reaction was continued for 4 hours, and when no more water was being removed by distillation, the reaction mixture was stopped. The reaction solution was neutralized with an aqueous sodium hydroxide solution and washed with water. After removing the aqueous layer, toluene was removed by distillation under reduced pressure to obtain ester compound 1 having a carboxylic acid unit with 18 carbon atoms.

[0147] <Synthesis of ester compounds 2-6> Ester compounds 2 to 6 were obtained in the same manner as the synthesis example of ester compound 1, except that the raw materials used in the formulation were changed as shown in Table 3.

[0148] [Table 3]

[0149] <Example of toner particle 1 manufacturing> • Binding resin 1,100 units • Carbon black (Nipex35, manufactured by Orion Engineered Carbons) 10 units • Ester compounds 1.6 parts • Nigrosine compound (NUBIAN BLACK TN-870, manufactured by Orient Chemical Industry Co., Ltd.) 3 parts The above raw materials were mixed in a Henschel mixer for 3 minutes, then melt-kneaded in a twin-screw extruder PCM-30 heated to 160°C. After cooling with a cooling belt (cooling water 15°C), the mixture was coarsely ground in a hammer mill. The toner temperature immediately after the discharge port during melt-kneading was 155°C. This coarsely ground material was finely ground in a turbo mill (manufactured by Turbo Industries Co., Ltd.) with the exhaust temperature adjusted to 45°C, and the resulting finely ground material was classified in an air classifier to obtain toner particles 1 (D4 = 7.6 μm).

[0150] <Manufacturing example of toner particles 2-11> Toner particles 2 to 11 were obtained in the same manner as in the manufacturing example of toner particle 1, except that the raw materials used in the formulation were changed as shown in Table 4.

[0151] [Table 4]

[0152] <Example of manufacturing silicone resin particles 1> (First step) In a reaction vessel equipped with a thermometer and a stirrer, add 360 parts of water and 5.0% by mass hydrochloric acid: 15 parts were added to make a homogeneous solution. This was stirred at 25°C while adding methyltrimethoxy. Add 136.0 parts of silane, stir for 5 hours, then filter to obtain the silanol compound or A clear reaction solution containing a partial condensate was obtained.

[0153] (Second process) In a reaction vessel equipped with a thermometer, stirrer, and dropping device, 440 parts of water were added, and 17 parts of 10.0% by mass aqueous ammonia were added to form a homogeneous solution. While stirring at 35°C, 100 parts of the reaction solution obtained in the first step were added dropwise over 30 minutes, and the mixture was stirred for 6 hours to obtain a suspension. The resulting suspension was centrifuged to settle the fine particles, which were then removed and dried in a drying oven at 200°C for 24 hours.

[0154] (Third step) 100 parts of the fine particles obtained in the second step, 3.75 parts of dimethyl silicone oil (KF-96-50cs, manufactured by Shin-Etsu Chemical Co., Ltd.), and 1000 parts of ethanol were stirred and mixed. The solvent was then removed using an evaporator and the mixture was dried to obtain silicone resin particles 1.

[0155] Regarding the obtained silicone resin particles 1, the solid as described above 29The T3 unit structure ratio was determined by Si-NMR analysis. The obtained T3 unit structure ratio was 0.5. Furthermore, silicone resin particles 1 were dispersed in toluene and allowed to stand for 24 hours, after which the toluene-insoluble components were separated by centrifugation. The obtained insoluble components were dried at 120°C for 2 hours, and the dry mass was measured. Based on the obtained dry mass, the soluble content of the silicone resin particles was calculated to be 0.5%. In addition, the weight-average molecular weight was determined by analyzing the toluene-soluble components using the GPC measurement method described above. The weight-average molecular weight of the toluene-soluble components of silicone resin particles 1 was 5000.

[0156] <Manufacturing examples of silicone resin particles 2-16> Silicone resin particles 2 to 16 were obtained in the same manner as the production example of silicone resin particle 1, except that the raw materials and process conditions used were changed as shown in Table 5. All silicone oils in Table 5 are products of Shin-Etsu Chemical Co., Ltd.

[0157] [Table 5]

[0158] <Example of Toner 1 manufacturing> • Toner particles 1 100 copies • Silicone resin particles 1 0.50 parts • Alumina particles (AA-04, manufactured by Sumitomo Chemical Co., Ltd.) 0.50 parts The above raw materials were added to an FM mixer (FM10C model, manufactured by Nippon Coke Industries Co., Ltd.) after the water temperature inside the jacket had stabilized at 50°C ± 1°C. Mixing was started at a peripheral speed of 38 m / sec with the rotating blades, and mixed for 7 minutes while controlling the water temperature and flow rate inside the jacket to stabilize the tank temperature at 50°C ± 1°C. The resulting mixture was sieved through a mesh with a mesh opening of 75 μm to obtain toner 1.

[0159] The obtained toner 1 was separated into binder resin component and ester compound component using the GPEC method described above. 1Analysis by 1H-NMR and reaction pyrolysis GC / MS confirmed the presence of an alkenyl succinic acid unit having an alkenyl group with 18 carbon atoms. Furthermore, analysis of the obtained ester compound by reaction pyrolysis GC / MS confirmed the presence of a carboxylic acid unit with 18 carbon atoms.

[0160] The mass ratio of silicone resin particles to alumina particles was determined by analysis using the aforementioned X-ray fluorescence method. The obtained mass ratio of silicone resin particles to alumina particles was 50 / 50. In addition, the silicone resin particles and alumina particles were observed using SEM with the aforementioned method, and the number-average particle diameter was determined. The number-average particle diameter of the silicone resin particles was 100 nm. The number-average particle diameter of the alumina particles was 500 nm.

[0161] <Manufacturing examples for toners 2-32> Toners 2 to 32 were obtained in the same manner as the manufacturing example of toner 1, except that the raw materials used in the formulation were changed as shown in Table 6.

[0162] [Table 6]

[0163] <Example 1> A laser printer (product name: HP Color Laser Jet Enterprise M653dn, manufactured by HP; print speed 56 pages / minute (A4 size)) was prepared as the electrophotographic device. Toner 1 was filled into the process cartridge dedicated to this electrophotographic device. After allowing the electrophotographic device and process cartridge to acclimate to the environment by leaving them in a low-temperature, low-humidity environment of 15°C and 10% relative humidity for more than 24 hours, the process cartridge was installed in the electrophotographic device and the following evaluation was performed. The evaluation paper used was A4 color laser copier paper (Canon, 80 g / m²). 2 ) was used.

[0164] (Developing roller filming evaluation) A durability test was conducted by repeatedly outputting an image (hereinafter referred to as the "E character image") in which the letter "E" of the alphabet is printed so that it covers 1% of the area of ​​an A4 sheet of paper. The conditions of the durability test were to output 50,000 electrophotographic images by repeatedly performing an intermittent image forming operation in which the rotation of the photosensitive drum was stopped completely for about 5 seconds after outputting two E character images, and then the image output was restarted.

[0165] After printing 50,000 images, halftone images were output, and the occurrence of vertical streaks due to uneven shading caused by the development roller filming was evaluated based on the following criteria. The evaluation results are shown in Table 8. Rank A: No vertical streaks present. Rank B: One vertical streak appears. Rank C: 2-4 vertical streaks may appear. Rank D: Five or more vertical streaks are present.

[0166] (Evaluation of overlap) Using the process cartridge after the development roller filming evaluation described above, a solid white image was printed onto evaluation paper whose reflectance density had been measured in advance. The difference in reflectance density before and after image output was defined as the cover value. The obtained cover value was evaluated based on the following criteria. Rank A: Less than 1% Rank B: 1% to less than 2.5% Rank C: 2.5% to less than 5% Rank D: 5% to less than 10%

[0167] <Examples 2-26, Comparative Examples 1-6> The evaluation was carried out in the same manner as in Example 1, except that the toner used to fill the process cartridge was the combination shown in Table 7. The evaluation results are shown in Table 8.

[0168] [Table 7]

[0169] [Table 8]

[0170] As shown in Table 8, it was found that using the toners from Examples 1 to 26 makes it possible to suppress developing roller filming and fogging.

[0171] On the other hand, Comparative Example 1, which did not contain silicone resin particles, and Comparative Example 2, which did not contain a nigrosine compound, showed poor results in developing roller filming and fogging suppression. Furthermore, Comparative Examples 3 and 4, in which the alkenyl group of the alkenyl succinic acid had 9 or 23 carbon atoms, also showed poor developing roller filming suppression. In addition, Comparative Examples 5 and 6, in which the carboxylic acid unit of the ester compound had 9 or 23 carbon atoms, also showed poor developing roller filming suppression. [Explanation of symbols]

[0172] 1. Toner container, 2. Toner, 3. Toner supply roller, 4. Developing roller, 5. Toner regulating member, 6. Photoreceptor, 7. Toner blowout prevention member

Claims

1. A toner having toner particles and an external additive, (1) The toner particles contain a binder resin, a positive charge control agent, and an ester compound, The binder resin contains a resin having a vinyl polymer portion and a polyester portion, the polyester portion contains alkenyl succinic acid units, and the alkenyl succinic acid units have alkenyl groups having 10 to 22 carbon atoms. The positive charge control agent is a nigrosine compound, The ester compound is an ester of pentaerythritol or dipentaerythritol with a saturated or unsaturated aliphatic monocarboxylic acid having 10 to 22 carbon atoms. (2) The external additive contains silicone resin particles, A toner characterized by the following features.

2. The toner according to claim 1, further comprising the aforementioned external additive, alumina particles.

3. The toner according to claim 2, wherein the external additive has a mass ratio of silicone resin particles to alumina particles of 30:70 to 70:

30.

4. The toner according to claim 2 or 3, wherein when the number-average particle diameter of the silicone resin particles is A (nm) and the number-average particle diameter of the alumina particles is B (nm), A and B satisfy the following formula (1). 0.05≦A / B<1.00...(1)

5. The toner according to claim 1 or 2, wherein the silicone resin particles have a T3 unit structure represented by the following formula (2). R 1 -SiO 3 / 2 ・・・(2) (In formula (2), R 1 (This represents an alkyl group or phenyl group with 1 to 6 carbon atoms.)

6. The silicone resin particles are solid 29 The toner according to claim 1 or 2, wherein, in Si-NMR measurement, the ratio of the area of ​​the peak derived from silicon having a T3 unit structure to the total area of ​​the peaks derived from all silicon elements is 0.50 or more and 1.00 or less.

7. The toner according to claim 1 or 2, wherein the silicone resin particles have a toluene-soluble content of 0.2% by mass or more and 5.0% by mass or less.

8. The toner according to claim 7, wherein the soluble content in toluene has a weight-average molecular weight equivalent to polystyrene, determined by GPC measurement, of 1,000 or more and 10,000 or less.

9. The toner according to claim 2, wherein the mass ratio of the content of silicone resin particles to the content of alumina particles in the toner (content of silicone resin particles: content of alumina particles) is 30:70 to 70:

30.

10. A process cartridge comprising toner, a developing roller that carries the toner, and a toner restricting member that contacts the developing roller and restricts the toner carried on the developing roller, wherein the process cartridge is detachably configured to be attached to the main body of an electrophotographic image forming apparatus, and the toner is the toner described in claim 1 or 2.

11. An electrophotographic image forming apparatus comprising toner, a photoreceptor on which an electrostatic latent image is formed, a developing roller that carries the toner and develops the electrostatic latent image into a toner image, and a toner regulating member that contacts the developing roller and regulates the toner carried on the developing roller, wherein the toner is the toner described in claim 1 or 2.

Images