JP2017198929A - toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner coping with high speed and long life of a device which can hold stable frictional electrification.SOLUTION: A toner has organic/inorganic composite fine particles and a hydrotalcite compound on a surface of toner base particles, where the organic/inorganic composite fine particles have such a structure that inorganic fine particles are embedded in vinyl resin particles, the inorganic fine particles are exposed to the surface of the organic/inorganic composite fine particles, an abundance ratio of the inorganic fine particles on the surface of the organic/inorganic composite fine particles is 20-70%, the organic/inorganic composite fine particles and the hydrotalcite compound have a surface potential of -900 to -400 V when charged by corona charging, and a time constant τ when the surface potential is attenuated is 200-2,000 seconds.SELECTED DRAWING: None

Description

  The present invention relates to a toner used in an electrophotographic image forming method for developing an electrostatic image.

  There is a need for free maintenance and simplification of the apparatus configuration. As a developing method that can cope with these requirements, there is a contact developing method using a non-magnetic one-component developer.

  In the one-component contact development method, the toner is easily deteriorated due to the rubbing between the toner regulating member and the toner carrier, and the silica or the like is easily peeled off, so that the charging property of the toner is lowered or the toner regulating member is fused and charged. It may cause defects or image defects. In order to output a high-quality image over a long period of time by the one-component contact development method, it is necessary to solve these problems. In recent years, with the spread of copying machines and printers using electrophotography, higher speed, longer life, and higher image quality are also required in the one-component contact development system.

  In order to stabilize the charging characteristics, a hydrotilesite compound has been conventionally used (Patent Document 1). In the case of a negatively charged toner, the hydrotilesite compound is charged with a reverse polarity to the toner base particles. Therefore, if the hydrotilesite compound exists on the toner surface when the charge is attenuated, the charge can be stabilized in a microcarrier manner.

  Further, studies have been made to suppress embedding of external additives existing on the toner surface into the toner surface, and attempts have been made to use large particle size external additives. Among them, it has been proposed to use organic-inorganic composite fine particles (for example, Patent Document 2).

JP 2006-23351 A WO2013 / 066291

  In the study by the present inventors, the addition of hydrotilesite compounds and organic / inorganic composite fine particles as described in Patent Documents 1 and 2 are sufficient for speeding up and extending the life. It became clear that it was difficult to cope with.

  In particular, in an apparatus that employs a one-component contact development system that is easily subjected to mechanical stress and that is difficult to impart stable charge to toner, it has been difficult to cope with an increase in speed and life.

  An object of the present invention is to provide a toner capable of solving the above problems.

  Specifically, it is an object of the present invention to provide a toner that can cope with an increase in the speed and life of the apparatus and that can maintain a stable triboelectric charge. By using the toner of the present invention, the occurrence of fog can be suppressed, and a high-definition image having a stable image density can be obtained.

The present invention is a toner mother particle, and a toner having organic-inorganic composite fine particles and a hydrotalcite compound on the surface of the toner mother particle,
The organic-inorganic composite fine particles have a structure in which inorganic fine particles are embedded in vinyl resin particles,
The inorganic fine particles are exposed on the surface of the organic-inorganic composite fine particles, and the abundance of the inorganic fine particles on the surface of the organic-inorganic composite fine particles is 20% or more and 70% or less,
The organic-inorganic composite fine particles and the hydrotalcite compound have a surface potential of −900 V or more and −400 V or less when charged by corona charging, and a time constant τ when the surface potential decays is 200 seconds or more and 2000 The present invention relates to a toner characterized by having a second or less.

  According to the present invention, it is possible to provide a toner that can cope with an increase in the speed and life of the apparatus and can maintain a stable triboelectric charge.

1 is a schematic cross-sectional view of an image forming apparatus according to an embodiment to which the present invention can be applied. 1 is a schematic cross-sectional view of a process cartridge according to an embodiment to which the present invention can be applied.

  The configuration of the present invention is as follows.

Toner base particles and toner having organic-inorganic composite fine particles and hydrotalcite compounds on the surface of the toner base particles,
The organic-inorganic composite fine particles have a structure in which inorganic fine particles are embedded in vinyl resin particles,
The inorganic fine particles are exposed on the surface of the organic-inorganic composite fine particles, and the abundance of the inorganic fine particles on the surface of the organic-inorganic composite fine particles is 20% or more and 70% or less,
The organic-inorganic composite fine particles and the hydrotalcite compound have a surface potential of −900 V or more and −400 V or less when charged by corona charging, and a time constant τ when the surface potential decays is 200 seconds or more and 2000 The present invention relates to a toner characterized by having a second or less.

  According to the study by the present inventors, by using the toner as described above, it is possible to suppress the toner dropping phenomenon that occurs when the toner is detached from the developing roller even in a long life and high speed system. Further, fog is hardly generated, the image density is stable, and a high-definition image can be obtained.

  As mentioned above, adding hydrotalcite compounds or large particle size external additives has the effect of improving charging stability and suppressing embedding of external additives, but is sufficient for long life and high speed systems. The effect is not obtained.

  In the one-component contact development method, the toner is charged when the toner passes between the developing roller and the developing blade. That is, the charge application site is smaller than that in the two-component development system in which toner is applied by contacting the magnetic carrier.

  In the one-component contact development method, it is necessary to carry the toner on the developing roller with electrostatic adhesion in order to convey the toner. For this reason, in the one-component contact development method, if the charge amount of the toner is not high, the toner is separated from the developing roller and the toner drops. In particular, in a high-speed system, since the developing roller rotates at a high speed, a strong centrifugal force acts on the toner, and toner drops easily occur.

  As a method of stabilizing the charging, there is a method of adding a component having a polarity opposite to that of the toner based on the idea of increasing the charging sites. Specifically, it is a method of adding an external additive having a microcarrier effect. Although this method has a certain effect on charging stabilization, it exhibits a different behavior from the toner at the time of development because of its reverse polarity. It is difficult to obtain.

  Further, there is a concept of utilizing the spacer effect to suppress toner deterioration and stabilize charging. For this purpose, there is a method of adding an external additive having a large particle diameter. However, adding an external additive having a large particle diameter reduces the toner adhesion, so that when the developing roller rotates at high speed, the toner is likely to fall off or scatter. Become.

  Therefore, the present inventors can obtain a toner that maintains a stable triboelectric charge even in a long life or high-speed system when a hydrotalcite compound and a specific organic-inorganic composite fine particle are used as external additives. all right.

  As a result of investigations focusing on the electrical characteristics of these external additives, it was found that the surface potential when charged by corona charging must be −900 V or more and −400 V or less. Furthermore, it has been found that the time constant τ when the surface potential decays needs to be 200 seconds or more and 2000 seconds or less.

  Although it is not clear whether the above-mentioned electrical characteristics are effective for a long life or a high-speed system, the present inventors consider as follows.

  When the surface potential of the external additive is within the above range when charged by corona charging, it is considered that the external additive is easily charged. Therefore, the hydrotalcite compound used in the present invention is easily charged. In addition, when charging is attenuated, a charge is injected onto the surface of the mother particle to charge the toner. The hydrotalcite compound used in the present invention has a time constant in the above range when the surface potential is attenuated. The toner can be charged well. Furthermore, since the potential is rapidly attenuated, charge-up is suppressed, and further, charging and decay are repeated, so that the microcarrier effect of the hydrotalcite compound can be continuously obtained. As a result, the entire toner can be uniformly charged without causing uneven charging.

  On the other hand, regarding the organic-inorganic composite fine particles, it is necessary not to inhibit the microcarrier effect of the hydrotalcite compound. For this purpose, the organic-inorganic composite fine particles need to have the same characteristics as the hydrotalcite compound with respect to the surface potential when charged by corona charging and the time constant at the time of attenuation.

  With respect to the hydrotalcite compound and the organic / inorganic composite fine particles, if the surface potential when charged by corona charging is less than −900 V, the toner is likely to be charged up because the chargeability is excessive. In this case, for example, the toner is carried on the developing roller, the toner on the outermost layer of the developing roller becomes difficult to be charged, and the toner may be detached from the developing roller. When the surface potential is larger than −400 V, the chargeability of the toner is too low. In this case, for example, the toner is detached from the developing roller.

  In addition, when the time constant τ when the surface potential of the hydrotalcite compound and the organic / inorganic composite fine particles decays is within the above range, the decay rate is moderate, and charge is imparted to the toner base particles. And the frequency with which it can be applied is sufficient. As a result, the toner has a sufficient charge amount, and for example, the toner can be prevented from being detached from the developing roller.

<Hydrotalcite compounds>
The hydrotalcite compound is not particularly limited as long as the above properties are satisfied, but those represented by the following structural formula can be used.

^{_{M 2+ y M 3+ x (OH}} ) 2 A n- (x / n) · mH 2 O
^{(M 2+} represents a divalent metal ^{ion, M 3+} represents a trivalent metal ^{ion, A n-represents} an n-valent anion, 0 <x ≦ 0.5, is x + y = 1, m ≧ 0.)
The divalent metal ion and the trivalent metal ion may be a solid solution containing a plurality of different elements, or may contain a small amount of a monovalent metal ion in addition to these metal ions.

Examples of metals that give divalent metal ions include Mg, Zn, Ca, Ba, Ni, Sr, Cu, and Fe. Examples of metals that give trivalent metal ions include Al, B, Ga, Fe, and Co. , In. As the divalent metal ion, Mg ²⁺ is preferably the main component, and as the trivalent metal ion, Al ³⁺ is preferably the main component.

Examples of n-valent anions include CO ₃ ²⁻ , OH ⁻ , Cl ⁻ , I ⁻ , F ⁻ , Br ⁻ , SO ₄ ²⁻ , HCO ₃ ²⁻ , CH ₃ COO ⁻ , and NO ₃ ⁻ . These may be single or plural.

  The hydrotalcite compound may be surface-treated with oils such as higher fatty acids, coupling agents, esters and silicone oil. Examples of higher fatty acids include stearic acid, oleic acid, lauric acid and the like. Of these, stearic acid is more preferable. Moreover, as a silicone oil, a dimethyl silicone oil is preferable.

  By treating the surface of the hydrotalcite compound with stearic acid or dimethyl silicone oil, the effect of the hydrotalcite compound as a microcarrier is better expressed. As a result, the charging property that suppresses the charge-up of the toner is stabilized, so that the fog is suppressed and the image density is easily stabilized.

  A conventionally known method can be used as the surface treatment method of the hydrotalcite compound with the surface treatment agent. For example, there is a method of dissolving and mixing a surface treatment agent in a solvent, or wet mixing with an untreated hydrotalcite compound after being dissolved by heating to form a liquid. In addition, there is a method of mechanically dry-mixing a fine powdery surface treatment agent and a hydrotalcite compound. After the surface treatment, means such as washing, dehydration, drying, pulverization, and classification are appropriately performed as necessary. And a hydrotalcite-type compound subjected to surface treatment can be obtained.

  The number average particle size of the hydrotalcite compound is preferably 100 nm or more and 1000 nm or less. More preferably, it is 100 nm or more and 800 nm or less.

  The degree of hydrophobicity of the hydrotalcite compound is preferably 30 to 95%. When the degree of hydrophobicity is within the above range, it is difficult to be affected by humidity while suppressing charge-up, and more stable triboelectric charging can be obtained.

Further, the BET specific surface area of the hydrotalcite compound is preferably ² to 15 m ² / g from the viewpoint of adhesion to the toner particles.

  The addition amount of the surface-treated hydrotalcite compound is preferably 0.03 to 3.00 parts by mass, more preferably 0.05 to 2.50 with respect to 100 parts by mass of the toner base particles. It is preferable that it is a mass part.

Furthermore, the volume resistance value of the hydrotalcite compound used in the present invention is preferably 1.0 × 10 ^{10 to} 1.0 × 10 ¹⁶ Ω · cm from the viewpoint of maintaining good charge. Moreover, it is preferable that the Mohs hardness of this hydrotalcite compound is 2.0-4.0.

<Organic inorganic composite fine particles>
It is important that the external additive used as the spacer particle has the above-described electrical characteristics. Accordingly, it is possible to suppress the action of the hydrotalcite compound as a microcarrier.

  As a result of investigations by the present inventors, it was found that organic-inorganic composite fine particles having the following characteristics have predetermined electrical characteristics.

  That is, (1) particles having a structure in which inorganic fine particles are embedded in vinyl-based resin particles, and (2) inorganic fine particles are exposed on the surface, and the presence rate of inorganic fine particles on the surface is 20% or more. The organic-inorganic composite fine particles are required to be 70% or less.

  The present inventors consider the reason why such organic-inorganic composite fine particles have the above-described electrical characteristics as follows. In general, inorganic fine particles have a high time constant τ when the surface potential is attenuated. On the other hand, the resin fine particles have a tendency that the surface potential of the external additive is too high due to corona charging. Since the inorganic fine particles are scattered on the surface of the vinyl resin particles, the balance between the charge retention in the vinyl resin portion and the charge attenuation in the inorganic fine particle portion is maintained in a suitable state. I believe that. In order to attenuate the charge, the vinyl resin portion and the inorganic fine particle portion need to be in close contact with each other. Therefore, it is considered that the inorganic fine particles need to be embedded in the vinyl resin particles.

  When the abundance ratio of the inorganic fine particles on the surface of the organic / inorganic composite fine particles is within the above range, it is possible to suppress toner charge-up while achieving a toner having appropriate charge. More preferably, the abundance of inorganic fine particles is 30% or more and 60% or less.

  The organic-inorganic composite fine particles preferably have a shape factor SF-1 of 100 or more and 150 or less and a shape factor SF-2 of 103 or more and 120 or less. When it has such a shape, it becomes easy to moderately control the frictional charging of the toner. More preferably, SF-1 is 110 or more and 140 or less, and SF-2 is 105 or more and 120 or less.

  The organic-inorganic composite fine particles preferably have a number average particle diameter of 50 nm or more and 400 nm or less. When the number average particle size of the organic-inorganic composite fine particles is in the above range, the relationship with the size of the hydrotalcite compound is appropriate, and the microcarrier effect of the hydrotalcite compound can be sufficiently exhibited. In addition, if it is within the above range, detachment from the toner base particles can be suppressed. More preferably, the number average particle diameter is from 80 nm to 250 nm, and even more preferably from 90 nm to 200 nm.

  When the number average particle size of the organic-inorganic composite fine particles is “A” and the number average particle size of the hydrotalcite compound is “B”, B / A is preferably 1.5 or more and 10.0 or less. . By satisfying this relationship, the effect of the hydrotalcite compound as a microcarrier is sufficiently exhibited.

  The content of the organic / inorganic composite fine particles is preferably 0.5 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the toner base particles. If it is within the above range, unevenness of toner regulation occurs, the image density is stabilized, and the effect of the hydrotalcite compound as a microcarrier is sufficiently exhibited. More preferably, it is 0.5 parts by mass or more and 4.0 parts by mass or less with respect to 100 parts by mass of the toner base particles.

  The organic-inorganic composite fine particles that can be used in the present invention can be produced by, for example, the method described in WO2013 / 063291. Other examples include a manufacturing method in which inorganic fine particles are injected into resin particles later to create organic-inorganic composite fine particles, and a manufacturing method in which inorganic fine particles and dissolved resin are dispersed in a solution to create organic-inorganic composite fine particles. It is done.

  In the case where organic fine particles are produced by implanting inorganic fine particles into the resin particles later, first, the organic resin particles are produced. The resin particles can be made by freezing and pulverizing the resin to make fine particles, by dissolving or emulsifying the dissolved resin in a solution to obtain fine particles, and polymerizing the resin component monomers by emulsion polymerization or suspension polymerization. And a method of obtaining resin particles.

  As a method of implanting inorganic fine particles into organic resin particles, a hybridizer (manufactured by Nara Machinery Co., Ltd.), Nobilta (manufactured by Hosokawa Micron Co., Ltd.), mechanofusion (manufactured by Hosokawa Micron Co., Ltd.), Hi-Flex Grall (manufactured by Earth Technica Co., Ltd.), Can do. By treating the organic resin particles and the inorganic fine particles with these apparatuses, the inorganic fine particles can be uniformly fixed on the surface of the organic resin particles, and organic-inorganic composite fine particles can be prepared.

  The vinyl-based resin component of the organic / inorganic composite fine particles includes styrene such as polystyrene and polyvinyltoluene and homopolymers thereof, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer. Styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene- Methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether Copolymer, styrene -Styrene copolymers such as vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer; polymethyl methacrylate, Polybutyl methacrylate, polyvinyl acetate, polyvinyl butyral, polyacrylic acid resin, polyolefin resin, polyethylene, polypropylene, polyacrylonitrile, polyvinyl acetate, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether and polyvinyl ketone, vinyl chloride-acetic acid Vinyl copolymers, fluororesins such as polytetrafluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, polychlorotrifluoroethylene, etc. can be used. It can is used alone or in combination of plural kinds.

  Examples of the polymerizable monomer used when the vinyl resin component is obtained by polymerization include styrenes such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, and p-ethylstyrene. Monomer, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, acrylic acid Acrylic esters such as 2-chloroethyl and phenyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, methacrylic acid 2-ethylhexyl, meta Acrylic acid stearyl, phenyl methacrylate, dimethylaminoethyl methacrylate, methacrylic acid esters such as diethylaminoethyl methacrylate and other acrylonitrile, methacrylonitrile, and the like monomers acrylamide. These monomers can be used alone or in combination.

  Examples of the inorganic fine particles of the organic / inorganic composite fine particles include fine particles of silica, alumina, titania, zinc oxide, strontium titanate, cerium oxide, calcium carbonate, and the like. In particular, when the inorganic fine particles are silica, it is preferable because the chargeability is excellent and an effect on the developability is obtained. Silica may be obtained by a dry method such as fumed silica, or may be obtained by a wet method such as sol-gel silica.

  The content of the inorganic fine particles in the organic / inorganic composite fine particles is preferably 30% by mass or more and 80% by mass or less based on the organic / inorganic composite fine particles from the viewpoint of production stability and particle size distribution control.

  The organic / inorganic composite fine particles or the inorganic fine particles used for the organic / inorganic composite fine particles are preferably chemically hydrophobized with an organosilicon compound that physically adsorbs to them. As a preferred method, silica fine particles produced by vapor phase oxidation of a silicon halogen compound are treated with an organosilicon compound. Examples of such organosilicon compounds include the following.

  Hexamethyldisilazane, methyltrimethoxysilane, octyltrimethoxysilane, isobutyltrimethoxysilane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichloro Silane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethylacetoxysilane , Dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, 1-hexamethyl Disiloxane, 1,3-divinyltetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane, and 2 to 12 siloxane units per molecule, each bonded to a terminal Si unit Dimethylpolysiloxane containing hydroxyl groups. These are used alone or in a mixture of two or more.

  The surface of the organic / inorganic composite fine particles or the inorganic fine particles used for the organic / inorganic composite fine particles may be treated with an organic silicon compound or silicone oil. In the surface treatment, the organic / inorganic composite fine particles may be surface-treated, or the surface-treated inorganic fine particles may be combined with a resin.

As the silicone oil, those having a viscosity at 25 ° C. of 30 to 1000 mm ² / s are preferably used. For example, dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene modified silicone oil, chlorophenyl silicone oil, and fluorine modified silicone oil are particularly preferred.

  Examples of the method for treating silicone oil include the following methods. A method in which silica fine particles treated with a silane coupling agent and silicone oil are directly mixed using a mixer such as a Henschel mixer. A method of spraying silicone oil onto silica fine particles as a base. Alternatively, it is more preferable to dissolve or disperse silicone oil in a suitable solvent, and then add and mix inorganic fine particles to remove the solvent.

  The toner of the present invention preferably contains inorganic fine particles in addition to the hydrotalcite compound and the organic / inorganic composite fine particles. Chargeability and fluidity can be imparted by incorporating inorganic fine particles. Examples of the inorganic fine particles include finely-processed silica such as wet-process silica, dry-process silica, silica treated with silane coupling agent, titanium coupling agent, or silicone oil, or titanium oxide. It is done.

  Hereinafter, the configuration of the toner base particles will be described.

  In the present invention, the toner base particles may be those used in general toners without limitation, but usually contain a binder resin, a colorant, and, if necessary, a wax, a charge control agent and the like. To do.

  Binder resins include styrene such as polystyrene and polyvinyltoluene, and substituted homopolymers thereof; styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate Copolymer, Styrene-ethyl acrylate copolymer, Styrene-butyl acrylate copolymer, Styrene-octyl acrylate copolymer, Styrene-dimethylaminoethyl acrylate copolymer, Styrene-methyl methacrylate copolymer Styrene-acrylic copolymers such as styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer, styrene- Vinyl ethyl ether copolymer, Styrene copolymers such as tylene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer; polymethyl methacrylate , Polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyester resin, polyamide resin, epoxy resin, polyacrylic acid resin can be used, and these can be used alone or in combination. Can do. Among these, a styrene acrylic copolymer represented by styrene-butyl acrylate is particularly preferable in terms of development characteristics, fixability and the like.

  Examples of wax components that can be used in the toner according to the present invention include paraffin wax, microcrystalline wax, petroleum wax such as petrolatum and derivatives thereof, montan wax and derivatives thereof, hydrocarbon wax and derivatives thereof according to the Fischer-Tropsch method, polyethylene, Polyolefin waxes such as polypropylene and derivatives thereof, natural waxes such as carnauba wax and candelilla wax and derivatives thereof, and the like include oxides, block copolymers with vinyl monomers, and graft modified products. Furthermore, fatty acids such as higher aliphatic alcohols, stearic acid and palmitic acid, or compounds thereof, acid amide waxes, ester waxes, ketones, hydrogenated castor oil and derivatives thereof, plant-based waxes, animal waxes, and silicone resins can also be used. .

  As the black colorant, carbon black, a magnetic material, and a toned color of each color using a yellow / magenta / cyan colorant shown below are used. In particular, since dyes and carbon black have many polymerization-inhibiting properties, care must be taken when using them.

  Examples of the yellow colorant include compounds typified by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds. Specifically, the following C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 73, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 128, 129, 138, 147, 150, 151, 154, 155, 168, 180, 185, 214.

  Examples of the magenta colorant include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Specifically, the following C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, 238, 254, 269, C.I. I. And CI Pigment Bio Red 19.

  Examples of cyan colorants include copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, and basic dye lake compounds. Specifically, C.I. I. Pigment blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66.

  These colorants can be used alone or in combination and further in the form of a solid solution. The colorant is selected from the viewpoints of hue angle, saturation, brightness, light resistance, OHP transparency, and dispersibility in the toner. The added amount of the colorant is used by adding 1 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer or binder resin.

  Furthermore, the toner of the present invention may be a magnetic toner containing a magnetic material as a colorant. In this case, the magnetic material can also serve as a colorant. Magnetic materials include iron oxides such as magnetite, hematite and ferrite; metals such as iron, cobalt and nickel or aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, Examples include alloys of metals such as calcium, manganese, selenium, titanium, tungsten, vanadium, and mixtures thereof. The magnetic material is more preferably a surface-modified magnetic material. In the case of producing a magnetic toner by a polymerization method, it is preferable to apply a hydrophobic treatment with a surface modifier that is a substance that does not inhibit polymerization. Examples of such surface modifiers include silane coupling agents and titanium coupling agents. These magnetic materials preferably have a number average particle size of 2 μm or less, more preferably 0.1 to 0.5 μm. The amount to be contained in the toner particles is 20 to 200 parts by mass, particularly preferably 40 to 150 parts by mass with respect to 100 parts by mass of the polymerizable monomer or binder resin.

  In the toner of the present invention, a charge control agent may be used in order to keep the toner chargeability stable regardless of the environment.

  Examples of the negative charge control agent for controlling the toner to be negatively charged include the following. Monoazo metal compound, acetylacetone metal compound, aromatic oxycarboxylic acid, aromatic dicarboxylic acid, oxycarboxylic acid and dicarboxylic acid-based metal compound, aromatic oxycarboxylic acid, aromatic mono- and polycarboxylic acid and metal salt thereof, Examples include anhydrides, esters, phenol derivatives such as bisphenol, urea derivatives, metal-containing salicylic acid compounds, metal-containing naphthoic acid compounds, boron compounds, quaternary ammonium salts, calixarene, and resin charge control agents.

  Examples of the positive charge control agent for controlling the toner to be positively charged include the following. Nigrosine-modified products of nigrosine and fatty acid metal salts, etc .; guanidine compounds; imidazole compounds; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and the like Phosphonium salts and other onium salts and their lake pigments; triphenylmethane dyes and their lake pigments (as rake agents, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid Acid, ferricyanide, ferrocyanide, etc.); metal salt of higher fatty acid; diorganotin oxide such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; DOO, dioctyl tin borate, such as diorganotin tin borate such dicyclohexyl tin borate; resin-based charge control agents.

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

  Among them, as the charge control agent other than the resin charge control agent, a metal-containing salicylic acid compound is preferable, and the metal is particularly preferably aluminum or zirconium. A particularly preferred control agent is an aluminum salicylate compound.

  As the resin charge control agent, it is preferable to use a polymer or copolymer having a sulfonic acid group, a sulfonic acid group or a sulfonic acid ester group, a salicylic acid moiety, or a benzoic acid moiety.

  A preferable blending amount of the charge control agent is 0.01 to 20.0 parts by mass, more preferably 0.05 to 10.0 parts by mass with respect to 100.0 parts by mass of the binder resin.

  The toner of the present invention preferably has an average circularity of 0.960 or more. Further, when the toner has a circularity of 0.99 or more and a content of 10% or more, the fine line reproducibility can be improved more favorably.

  The toner of the present invention can be used as a one-component developer, but can also be mixed with a magnetic carrier and used as a two-component developer.

  Examples of the magnetic carrier include iron powder with oxidized surface or non-oxidized iron powder; metal particles such as iron, lithium, calcium, magnesium, nickel, copper, zinc, cobalt, manganese, rare earth, and alloy particles thereof. Commonly known materials such as magnetic particles such as oxide particles; ferrite; and a magnetic material-dispersed resin carrier (so-called resin carrier) containing a magnetic material and a binder resin that holds the magnetic material in a dispersed state are used. it can.

  When the toner of the present invention is mixed with a magnetic carrier and used as a two-component developer, the mixing ratio of the magnetic carrier is preferably 2 to 15% by mass as the toner concentration in the developer.

  The production method for producing the toner base particles is not particularly limited. A method for producing toner base particles directly in a hydrophilic medium such as suspension polymerization method, interfacial polymerization method or dispersion polymerization method (hereinafter also referred to as polymerization method), a pulverization method, or a production method for forming a hot sphere after pulverization Etc. The suspension polymerization method is preferred because the individual particles are substantially spherical and the distribution of charge amount is relatively uniform, so that it has high transferability.

  In the suspension polymerization method, a polymerizable monomer composition having a polymerizable monomer, a colorant, a wax and the like is dispersed in an aqueous medium to produce droplets of the polymerizable monomer composition. In this polymerization method, toner base particles are produced through at least a particle process and a polymerization process for polymerizing the polymerizable monomer in the droplets. And when manufacturing the toner of this invention, it is preferable to contain low molecular weight resin in a polymerizable monomer composition.

  In the toner of the present invention, the toner base particles preferably have at least a core portion and a shell portion. By adopting such a structure, it is possible to prevent poor charging and blocking due to leaching of the core part to the toner particle surface. Further, it is more preferable that a surface layer portion having a resin composition different from that of the shell portion is present on the surface of the shell portion. The presence of this surface layer portion can further improve environmental stability, durability, and blocking resistance.

  A preferable example of the polymerizable monomer that can be used when the toner base particles are produced by a polymerization method is a vinyl polymerizable monomer. For example, styrene; α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, p Styrene derivatives such as -n-hexyl styrene, pn-octyl, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p-phenyl styrene; 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- Acrylic polymerizable monomers such as nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, 2-benzoyloxyethyl acrylate; 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, dibutyl phosphate Methacrylic polymerizable monomers such as methyl methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, vinyl benzoate, vinyl formate; vinyl methyl ether; And vinyl ethers such as vinyl ethyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropyl ketone.

  The shell portion is composed of a vinyl polymer formed from these vinyl polymerizable monomers or an added vinyl polymer. Among these vinyl polymers, a styrene polymer, a styrene-acrylic copolymer, or a styrene-methacrylic copolymer is preferable from the viewpoint of efficiently covering the wax mainly forming the inside or the central portion.

  As a material constituting the core portion, wax is preferable.

  As a mixer for externally adding an external additive to toner base particles, FM mixer (manufactured by Nippon Coke Industries Co., Ltd.), super mixer (manufactured by Kawata Corp.), nobilta (manufactured by Hosokawa Micron Corp.), hybridizer (Nara Machinery Co., Ltd.) Manufactured). The external addition device is not particularly limited as long as desired toner characteristics can be obtained.

  Examples of the sieving device used for sieving coarse particles after external addition include the following. Ultrasonic (manufactured by Sakae Sangyo Co., Ltd.); Resonator Sheave, Gyroshifter (Tokusu Kosakusha Co., Ltd.); Vibrasonic System (manufactured by Dalton Co.); Soniclean (manufactured by Shinto Kogyo Co., Ltd.); Turbo Screener (manufactured by Turboe Sangyo Co., Ltd.); Perform using a micro shifter (manufactured by Hadano Sangyo Co., Ltd.)

  An image forming method to which the present invention is applied will be described below with reference to FIG.

  FIG. 1 is a schematic cross-sectional view of an image forming apparatus 100 using an image forming method to which the toner of the present invention can be applied. The image forming apparatus 100 is a full-color laser printer that employs an inline method and an intermediate transfer method. The image forming apparatus 100 can form a full-color image on a recording material (for example, recording paper, plastic sheet, cloth, etc.) according to the image information. The image information is input to the image forming apparatus main body 100A from an image reading apparatus connected to the image forming apparatus main body 100A or a host device such as a personal computer connected to the image forming apparatus main body 100A in a communicable manner.

  The image forming apparatus 100 includes, as a plurality of image forming units, first, second, and third images for forming yellow (Y), magenta (M), cyan (C), and black (K) images, respectively. And fourth image forming units SY, SM, SC, and SK. The first to fourth image forming units SY, SM, SC, and SK are arranged in a line in a direction that intersects the vertical direction.

  The configurations and operations of the first to fourth image forming units SY, SM, SC, and SK are substantially the same except that the colors of the images to be formed are different. Therefore, in the following, unless there is a particular distinction, the subscripts Y, M, C, and K given to the reference numerals to indicate that they are elements provided for any color are omitted, and generally explain.

  The image forming apparatus 100 includes, as a plurality of image carriers, four drum-type electrophotographic photoreceptors, that is, the photoreceptor drums 1 arranged in parallel in a direction intersecting the vertical direction. The photosensitive drum 1 is rotationally driven by a driving means (drive source) (not shown) in the direction indicated by an arrow A (clockwise). Around the photosensitive drum 1, a charging roller 2 as a charging means for uniformly charging the surface of the photosensitive drum 1, a laser is irradiated based on image information, and an electrostatic image (electrostatic) is formed on the photosensitive drum 1. A scanner unit (exposure device) 3 is disposed as exposure means for forming a (latent image). Further, around the photosensitive drum 1, a developing unit (developing device) 4 as developing means for developing an electrostatic image as a toner image, toner remaining on the surface of the photosensitive drum 1 after transfer (transfer residual toner) A cleaning member 6 is disposed as a cleaning means for removing water. Further, an intermediate transfer belt 5 as an intermediate transfer body for transferring the toner image on the photosensitive drum 1 to the recording material 12 is disposed opposite to the four photosensitive drums 1.

  The developing unit 4 preferably uses toner of a non-magnetic one-component developer as a developer. The developing unit 4 performs reversal development by bringing a developing roller (described later) as a developer carrying member into contact with the photosensitive drum 1. That is, the developing unit 4 is a portion (image portion, exposure portion) in which the charge is attenuated by exposure on the photosensitive drum 1 with toner charged to the same polarity (negative polarity in this embodiment) as the charging polarity of the photosensitive drum 1. ) To develop the electrostatic image.

  The photosensitive drum 1, and the charging roller 2, the developing unit 4 and the cleaning member 6 as process means acting on the photosensitive drum 1, are integrated, that is, a process cartridge 7 is preferably integrated into a cartridge. Used for. The process cartridge 7 can be attached to and detached from the image forming apparatus 100 via mounting means such as a mounting guide and a positioning member provided in the image forming apparatus main body 100A. The process cartridges 7 for the respective colors all have the same shape, and the process cartridges 7 for the respective colors have yellow (Y), magenta (M), cyan (C), and blank (K) colors, respectively. Toner is contained.

  The intermediate transfer belt 5 formed of an endless belt as an intermediate transfer member abuts on all the photosensitive drums 1 and circulates (rotates) in the direction of arrow B (counterclockwise) in the figure. The intermediate transfer belt 5 is wound around a driving roller 51, a secondary transfer counter roller 52, and a driven roller 53 as a plurality of support members.

  On the inner peripheral surface side of the intermediate transfer belt 5, four primary transfer rollers 8 as primary transfer means are arranged in parallel so as to face the respective photosensitive drums 1. The primary transfer roller 8 presses the intermediate transfer belt 5 toward the photosensitive drum 1 to form a primary transfer portion N1 where the intermediate transfer belt 5 and the photosensitive drum 1 abut. A bias having a polarity opposite to the normal charging polarity of the toner is applied to the primary transfer roller 8 from a primary transfer bias power source (high voltage power source) as a primary transfer bias applying unit (not shown). As a result, the toner image on the photosensitive drum 1 is transferred (primary transfer) onto the intermediate transfer belt 5.

  In addition, a secondary transfer roller 9 as a secondary transfer unit is disposed at a position facing the secondary transfer counter roller 52 on the outer peripheral surface side of the intermediate transfer belt 5. The secondary transfer roller 9 is pressed against the secondary transfer counter roller 52 via the intermediate transfer belt 5 to form a secondary transfer portion N2 where the intermediate transfer belt 5 and the secondary transfer roller 9 come into contact. A bias having a polarity opposite to the normal charging polarity of the toner is applied to the secondary transfer roller 9 from a secondary transfer bias power source (high voltage power source) as a secondary transfer bias applying unit (not shown). As a result, the toner image on the intermediate transfer belt 5 is transferred (secondary transfer) to the recording material 12.

  More specifically, at the time of image formation, first, the surface of the photosensitive drum 1 is uniformly charged by the charging roller 2. Next, the surface of the charged photosensitive drum 1 is scanned and exposed by laser light corresponding to the image information emitted from the scanner unit 3, and an electrostatic image according to the image information is formed on the photosensitive drum 1. Next, the electrostatic image formed on the photosensitive drum 1 is developed as a toner image by the developing unit 4. The toner image formed on the photosensitive drum 1 is transferred (primary transfer) onto the intermediate transfer belt 5 by the action of the primary transfer roller 8.

  For example, when forming a full-color image, the above-described process is sequentially performed in the first to fourth image forming units SY, SM, SC, and SK, and the toner images of the respective colors are next superimposed on the intermediate transfer belt 5. The primary transfer.

  Thereafter, the recording material 12 is conveyed to the secondary transfer portion N2 in synchronization with the movement of the intermediate transfer belt 5. The four color toner images on the intermediate transfer belt 5 are secondarily transferred onto the recording material 12 collectively by the action of the secondary transfer roller 9 that is in contact with the intermediate transfer belt 5 via the recording material 12.

  The recording material 12 onto which the toner image has been transferred is conveyed to a fixing device 10 as a fixing unit. The toner image is fixed on the recording material 12 by applying heat and pressure to the recording material 12 in the fixing device 10.

  Further, the primary transfer residual toner remaining on the photosensitive drum 1 after the primary transfer process is removed and collected by the cleaning member 6. The secondary transfer residual toner remaining on the intermediate transfer belt 5 after the secondary transfer process is cleaned by the intermediate transfer belt cleaning device 11.

  Note that the image forming apparatus 100 can form a single-color or multi-color image using only one desired image forming unit or using only some (not all) image forming units. It is like that.

  Next, the overall configuration of the process cartridge 7 attached to the image forming apparatus 100 will be described.

  FIG. 2 is a schematic cross-sectional view (main cross-sectional view) of the process cartridge 7 as viewed along the longitudinal direction (rotational axis direction) of the photosensitive drum 1. The posture of the process cartridge 7 in FIG. 2 is a posture in a state where the process cartridge 7 is mounted on the image forming apparatus main body. When the positional relationship and direction of each member of the process cartridge are described below, the positional relationship and direction in this posture are described below. Etc.

  The process cartridge 7 is configured by integrating a photosensitive unit 13 including the photosensitive drum 1 and the developing unit 4 including a developing roller 17 and the like.

  The photoconductor unit 13 has a cleaning frame 14 as a frame that supports various elements in the photoconductor unit 13. The photosensitive drum 1 is rotatably attached to the cleaning frame 14 via a bearing (not shown). The photosensitive drum 1 is rotationally driven in the direction of the arrow A (clockwise) in accordance with the image forming operation by transmitting the driving force of a driving motor (not shown) as a driving means (driving source) to the photosensitive unit 13. Is done. In the present invention, the photosensitive drum 1 serving as the center of the image forming process is an organic photosensitive drum 1 in which an outer peripheral surface of an aluminum cylinder is coated with a functional undercoat layer, a carrier generation layer, and a carrier transfer layer in this order. It is preferable to use it.

  Further, the cleaning unit 6 and the charging roller 2 are disposed in the photosensitive unit 13 so as to come into contact with the peripheral surface of the photosensitive drum 1. The transfer residual toner removed from the surface of the photosensitive drum 1 by the cleaning member 6 falls and is stored in the cleaning frame 14.

  The charging roller 2 as charging means is driven to rotate by bringing the roller portion of conductive rubber into pressure contact with the photosensitive drum 1.

  Here, as a charging process, a predetermined DC voltage is applied to the core of the charging roller 2 with respect to the photosensitive drum 1, whereby a uniform dark portion potential (Vd) is applied to the surface of the photosensitive drum 1. Is formed. The spot pattern of the laser beam emitted in accordance with the image data by the laser beam from the scanner unit 3 described above exposes the photosensitive drum 1, and the exposed portion is charged on the surface by the carrier from the carrier generation layer. Disappears and the potential drops. As a result, an electrostatic latent image is formed on the photosensitive drum 1 with a predetermined light portion potential (Vl) at an exposed portion and a predetermined dark portion potential (Vd) at an unexposed portion.

  On the other hand, the developing unit 4 has a developing chamber in which a developing roller 17 as a toner carrying member for carrying toner 80 and a toner supply roller 20 as a supply member for supplying toner to the developing roller 17 are arranged. Yes.

  Further, the toner supply roller 20 forms an abutting portion N (a portion where the toner is sandwiched between the development roller 17 and the toner supply roller 20) between the development roller 17 and rotates in the same direction.

  A stirring and conveying member 22 is provided in the toner storage chamber 18. The agitating / conveying member 22 agitates the toner accommodated in the toner accommodating chamber 18 and also conveys the toner toward the upper portion of the toner supply roller 20 in the direction of arrow G in the figure.

  The developing blade 21 is disposed below the developing roller 17 and is in contact with the developing roller at a counter, and regulates the coating amount of toner supplied by the toner supply roller 20 and applies a charge. The developing blade 21 uses a leaf spring-like SUS thin plate having a thickness of 0.1 mm. The developing blade 21 uses the spring elasticity of the thin plate to form a contact pressure, and the surface thereof contacts the toner and the developing roller 17. . Here, the developing blade is not limited to this, and may be a thin metal plate such as phosphor bronze or aluminum. Alternatively, the surface of the developing blade 21 may be coated with a thin film such as polyamide elastomer, urethane rubber, or urethane resin.

  The toner is triboelectrically charged by rubbing between the developing blade 21 and the developing roller 17 to be charged, and at the same time the layer thickness is regulated. In the present invention, it is preferable to stabilize the toner coat layer by applying a predetermined voltage to the developing blade 21 from a blade bias power source (not shown).

  The developing roller 17 and the photosensitive drum 1 rotate so that the surfaces of the developing roller 17 and the photosensitive drum 1 move in the same direction (the direction from bottom to top in FIG. 2).

  In FIG. 2, the developing roller 17 is disposed in contact with the photosensitive drum 1, but the developing roller 17 is disposed adjacent to the photosensitive drum 1 at a predetermined interval. Also good.

  The toner charged negatively by frictional charging with respect to a predetermined DC bias applied to the developing roller 17 is transferred only to the bright portion potential portion from the potential difference in the developing portion contacting the photosensitive drum 1 and statically. Visualize the electrostatic latent image.

  The surfaces of the toner supply roller 20 and the developing roller 17 are preferably rotated in the same direction at the contact portion N. In FIG. 2, the toner supply roller 20 rotates in the direction of the arrow E (clockwise), and the developing roller 17 rotates in the direction of arrow D. As a result, the load on the toner can be reduced, and high image quality can be maintained even during long-term use. The toner supply roller 20 is an elastic sponge roller in which a foam layer is formed on the outer periphery of a conductive metal core. The toner supply roller 20 and the developing roller 17 are in contact with each other with a predetermined intrusion amount, that is, the indentation amount ΔE in which the toner supply roller 20 is recessed by the developing roller 17. In the present invention, the intrusion amount is preferably 0.3 to 1.5 mm, and more preferably 0.7 to 1.2 mm, from the balance between the peelability of the development residual toner and the load on the toner. .

  The toner supply roller 20 and the developing roller 17 are rotated with a peripheral speed difference in the same direction at the abutting portion N. With this operation, the toner supply roller 20 and the toner supply to the developing roller 17 are separated from each other. Is going. At this time, the toner supply amount to the developing roller can be adjusted by adjusting the potential difference between the toner supply roller and the developing roller. In the present invention, the peripheral speed of the supply roller is preferably 110 to 250%, more preferably 150 to 200% with respect to the peripheral speed of the developing roller. A DC bias may be applied to the toner supply roller.

  Hereinafter, the measuring method of various physical properties in the present invention will be described.

<Method for measuring the abundance of inorganic fine particles on the surface of organic / inorganic composite fine particles>
The abundance ratio of the inorganic fine particles on the surface of the organic / inorganic composite fine particles is measured by ESCA (X-ray photoelectron spectroscopy). When the inorganic fine particles are silica particles, it is calculated from the atomic weight of silicon derived from silica (hereinafter abbreviated as Si). Is done. ESCA is an analysis method for detecting atoms in a region of several nm or less in the depth direction of the sample surface. Therefore, it is possible to detect atoms on the surface of the organic / inorganic composite fine particles.

As a sample holder, a 75 mm square platen (provided with a screw hole of about 1 mm diameter for fixing the sample) attached to the apparatus was used. Since the screw hole of the platen penetrates, the hole is closed with a resin or the like, and a recess for measuring powder having a depth of about 0.5 mm is created. The measurement sample was packed in the concave portion with a spatula or the like, and then a sample was prepared.
The ESCA apparatus and measurement conditions are as follows.

Equipment used: Quantum 2000 manufactured by ULVAC-PHI
Analysis method: Narrow analysis Measurement conditions:
X-ray source: Al-Kα
X-ray conditions: 100μ25W15kV
Photoelectron capture angle: 45 °
PassEnergy: 58.70eV
Measurement range: φ100μm
Measurement was performed under the above conditions.

  The analysis method first corrects the peak derived from the C—C bond of the carbon 1s orbital to 285 eV. Thereafter, from the peak area derived from the silicon 2p orbit where the peak top is detected at 100 to 105 eV, the relative sensitivity factor provided by ULVAC-PHI is used to calculate the amount of Si derived from silica relative to the total amount of the constituent elements. .

  First, organic-inorganic composite fine particles are measured. In addition, the inorganic component particles used in preparing the organic-inorganic composite fine particles by the same method are measured. When the inorganic component is silica, the ratio of “Si amount when measuring organic / inorganic composite fine particles” to “Si amount when measuring silica particles” is the presence of the inorganic fine particles on the surface of the organic / inorganic composite fine particles in the present invention. Rate. In this measurement, calculation was performed using sol-gel silica particles (number average particle diameter 110 nm) as silica particles.

  The method for separating the organic / inorganic composite fine particles from the toner can be performed, for example, by the method described in the method for quantifying organic / inorganic composite fine particles and inorganic fine particles in the toner.

  Although the case where the inorganic fine particles are silica particles has been described, if the inorganic fine particles are not silica particles, an analysis focusing on the metal species may be performed using a database attached to the measuring apparatus.

<Method for measuring number average particle diameter of external additive>
The number average particle diameter of the external additive is measured using a scanning electron microscope “S-4800” (trade name; manufactured by Hitachi, Ltd.). The toner with the external additive added is observed, and the major axis of the primary particles of 100 external additives is randomly measured in the field of view enlarged up to 200,000 times to determine the number average particle size. The observation magnification is appropriately adjusted according to the size of the external additive.

<Measurement method of SF-1 and SF-2 of external additive>
The external additives SF-1 and SF-2 were observed on the toner surface with a scanning electron microscope (SEM) “S-4800” (manufactured by Hitachi, Ltd.). In a field of view that was magnified 100,000 to 200,000 times, the maximum length and perimeter of 100 primary particles were measured using image processing software Image-Pro Plus 5.1J (Media Cybernetics).

SF-1 and SF-2 were calculated by the following formulas, and the average values were taken as SF-1 and SF-2.
SF-1 = (maximum length of primary particles) ² / area of primary particles × π / 4 × 100
SF-2 = (peripheral length of primary particles) ² / area of primary particles × 100 / 4π
<Measuring method of average circularity of toner>
The average circularity of the toner is measured by a flow type particle image analyzer “FPIA-3000” (manufactured by Sysmex Corporation) under the measurement and analysis conditions during the calibration operation.

  A specific measurement method is as follows. First, about 20 mL of ion-exchanged water from which impure solids and the like are previously removed is placed in a glass container. In this, "Contaminone N" (nonionic surfactant, anionic surfactant, 10% by weight aqueous solution of neutral detergent for pH7 precision measuring instrument cleaning, made by organic builder, manufactured by Wako Pure Chemical Industries, Ltd. About 0.2 mL of a diluted solution obtained by diluting 3) with ion-exchanged water is added. Further, about 0.02 g of a measurement sample is added, and dispersion treatment is performed for 2 minutes using an ultrasonic disperser to obtain a dispersion for measurement. In that case, it cools suitably so that the temperature of a dispersion liquid may become 10 to 40 degreeC. As the ultrasonic disperser, a desktop type ultrasonic cleaner disperser (for example, “VS-150” (manufactured by VervoCrea)) having an oscillation frequency of 50 kHz and an electric output of 150 W is used. Ion exchange water is put, and about 2 mL of the above-mentioned Contaminone N is added to this water tank.

  For the measurement, the flow type particle image analyzer equipped with “UPlanApro” (magnification: 10 ×, numerical aperture: 0.40) as an objective lens is used. It was used. The dispersion prepared according to the above procedure is introduced into the flow type particle image analyzer, and 3000 particles are measured in the HPF measurement mode and in the total count mode. Then, the binarization threshold at the time of particle analysis is set to 85%, the analysis particle diameter is limited to the equivalent circle diameter of 1.985 μm or more and less than 39.69 μm, and the average circularity is obtained.

  In measurement, automatic focus adjustment is performed using standard latex particles (for example, “RESEARCH AND TEST PARTICLES Latex Microsphere Suspensions 5200A” manufactured by Duke Scientific) diluted with ion-exchanged water before starting the measurement. Thereafter, it is preferable to perform focus adjustment every two hours from the start of measurement.

  In the examples of the present application, a flow-type particle image analyzer that has been issued a calibration certificate issued by Sysmex Corporation, which has been calibrated by Sysmex Corporation, was used. Measurement was performed under the measurement and analysis conditions when the calibration certificate was received, except that the analysis particle size was limited to a circle equivalent diameter of 1.985 μm or more and less than 39.69 μm.

<Measuring method of weight average particle diameter (D4) and number average particle diameter (D1)>
The weight average particle diameter (D4) and number average particle diameter (D1) of the toner are measured with a fine particle size distribution measuring apparatus “Coulter Counter Multisizer 3” (registered trademark, Beckman 2) Effective measurement channel number 25,000 using “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.) and attached dedicated software “Beckman Coulter Multisizer 3 Version 3.51” for measurement condition setting and measurement data analysis Measurement was performed on the channel, and the measurement data was analyzed and calculated.

  As the electrolytic aqueous solution used for the measurement, special grade sodium chloride is dissolved in ion-exchanged water so as to have a concentration of about 1% by mass, for example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) can be used.

  Prior to measurement and analysis, the dedicated software was set as follows.

  In the “Standard measurement method (SOMME) change screen” of the dedicated software, set the total count in the control mode to 50000 particles, set the number of measurements once, and the Kd value is “standard particles 10.0 μm” (Beckman Coulter, Inc.) Set the value obtained using The threshold and noise level are automatically set by pressing the threshold / noise level measurement button. Also, the current is set to 1600 μA, the gain is set to 2, the electrolyte is set to ISOTON II, and the aperture tube flash after measurement is checked.

  In the “pulse to particle size conversion setting screen” of the dedicated software, the bin interval is set to logarithmic particle size, the particle size bin is set to 256 particle size bin, and the particle size range is set to 2 μm to 60 μm.

  The specific measurement method is as follows.

  (1) About 200 mL of the electrolytic solution is placed in a glass 250 mL round-bottom beaker dedicated to Multisizer 3, set on a sample stand, and the stirrer rod is stirred counterclockwise at 24 rpm. Then, dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the analysis software.

  (2) About 30 mL of the electrolytic aqueous solution is put in a glass 100 mL flat-bottom beaker, and “Contaminone N” (nonionic surfactant, anionic surfactant, organic builder consisting of an organic builder) is used as a dispersant. About 0.3 mL of a diluted solution obtained by diluting a 10% by weight aqueous solution of a neutral detergent for washing a vessel, manufactured by Wako Pure Chemical Industries, Ltd.) with ion-exchanged water three times as much is added.

  (3) Two oscillators with an oscillation frequency of 50 kHz are incorporated in a state where the phase is shifted by 180 degrees, and the ultrasonic disperser “Ultrasonic Disposition System Tetora150” (manufactured by Nikkiki Bios Co., Ltd.) having an electrical output of 120 W is installed in the water tank. Add 3 L of ion-exchanged water, and add about 2 mL of the contamination N to the water tank.

  (4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. And the height position of a beaker is adjusted so that the resonance state of the liquid level of the electrolyte solution in a beaker may become the maximum.

  (5) In a state where the electrolytic aqueous solution in the beaker of (4) is irradiated with ultrasonic waves, about 10 mg of toner is added to the electrolytic aqueous solution little by little and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. In addition, in ultrasonic dispersion, it adjusts suitably so that the water temperature of a water tank may be 10-40 degreeC.

  (6) To the (1) round bottom beaker installed in the sample stand, the (5) aqueous electrolyte solution in which the toner is dispersed is dropped using a pipette, and the measured concentration is adjusted to about 5%. Measurement is performed until the number of measured particles reaches 50,000.

  (7) The measurement data is analyzed with the dedicated software attached to the apparatus, and the weight average particle diameter (D4) and the number average particle diameter (D1) are calculated. When the graph / volume% is set in the dedicated software, the “average diameter” on the analysis / volume statistics (arithmetic average) screen is the weight average particle diameter (D4), and the graph / number% is set. The “average diameter” on the “analysis / number statistics (arithmetic average)” screen is the number average particle diameter (D1).

<Measurement method of surface potential when charged by corona charging and time constant τ when surface potential decays>
A corona charging device (manufactured by Rigaku Corp .: a charging device equipped with a power supply unit (KTK-2001) manufactured by Kasuga Electric Co., Ltd.) was measured with a device in which a surface electrometer (model 347 manufactured by Telk Corp.) was attached.

  7.0 to 7.5 mg of toner was placed on an aluminum sample pan (aluminum pan model: 900786.901, manufactured by TA Instruments Japan Co., Ltd.) as smooth as possible. The sample pan on which the toner is placed is placed on the turntable of the corona charging device, and the surface potential meter is adjusted so that the surface potential becomes zero. The measurement environment was a normal environment (23 ° C./50% Rh).

  A corona voltage of -20 kV and a grid voltage of −1 kV were applied to this sample pan for 30 seconds, and the surface potential of the sample was measured after the application. Specifically, the distance between the portion to which the corona voltage was applied and the grid was 14 mm, and the distance between the grid and the surface of the sample was 12.5 mm. The condition for applying the corona voltage was such that the sample was sufficiently charged. After charging the sample, the turntable of the apparatus was rotated and the surface potential of the sample was continuously measured for 10 minutes.

  When the potential drops, the time constant τ is a value represented by the following equation. The time constant τ is calculated by putting the value (V (t)) of the surface potential at time (t) in 10 minutes into this equation and fitting the equation with spreadsheet software (Excel: manufactured by Microsoft Corporation). did.

  Vmax is the maximum potential (initial surface potential)

  Hereinafter, the present invention will be specifically described based on examples. However, this does not limit the embodiment of the present invention. The number of parts in the examples is part by mass.

<Production example of organic-inorganic composite fine particles>
The organic-inorganic composite fine particles can be produced according to the description in the examples of WO 2013/066291 and the examples of JP-A-2005-202131.

  As the organic / inorganic composite fine particles 1 to 8 and 10 used in Examples described later, those prepared according to Example 1 of WO 2013/063291 were prepared. Moreover, as the organic-inorganic composite fine particles 9, those prepared according to the preparation example of the composite resin particles A disclosed in JP-A-2005-202131 were prepared. Table 1 shows the physical properties of the organic-inorganic composite fine particles 1 to 10.

<Silica particles>
As silica particles, KE-P10 (primary particle diameter 100 nm) manufactured by Nippon Shokubai Co., Ltd. was used. Table 1 shows the physical properties of the silica particles.

<Fluorine acrylic resin particles>
As the fluorine acrylic resin particles, FS-701 (primary particle diameter 100 nm) manufactured by Nippon Paint Industrial Coatings Co., Ltd. was used. Table 1 shows the physical properties of the fluoroacrylic resin particles.

<Melamine resin particles>
As the melamine resin particles, Eposter S (primary particle diameter 200 nm) manufactured by Nippon Shokubai Co., Ltd. was used. Table 1 shows the physical properties of the melamine resin particles.

<Production example of hydrotalcite compound>
[Production Example 1 of hydrotalcite compound]
An aqueous solution prepared by adding MgCl ₂ , CaCl ₂ and Al ₂ (SO ₄ ) ₃ and an aqueous alkaline solution were mixed to prepare a reaction slurry. The obtained reaction slurry was added to distilled water, and hydrothermal synthesis was performed at 200 ° C. for 20 hours. The slurry containing the obtained hydrotalcite compound was held at 95 ° C., and 5 parts by mass of stearic acid was added to 95 parts by mass of the solid content to perform surface treatment. Subsequently, it was washed with filtered water, dried at 100 ° C. for 24 hours, and crushed with an atomizer mill (manufactured by Dalton Co., Ltd.) to obtain hydrotalcite compound 1.

The obtained hydrotalcite compound 1 is represented by the following formula. ^{Wherein, A n-is} Cl ^- is.
_{^{Mg 2+ 0.55 Ca 2+ 0.02 Al 3+}} 0.43 (OH) 2 A n- (0.43 / n) · 0.41H 2 O

  Table 2 shows the physical properties of Hydrotalcite Compound 1.

[Production Examples 2 to 4 of hydrotalcite compound]
In Production Example 1 of the hydrotalcite compound, the hydrotalcite compounds 2 to 4 shown in Table 2 were obtained in the same manner except that the surface treatment agent type was changed. Table 2 shows the physical properties of hydrotalcite compounds 2-4. The obtained hydrotalcite compounds could all be represented by the above formula.

[Production Examples 5 to 8 of hydrotalcite compound]
In Production Example 4 of the hydrotalcite compound, MgCl ₂ , CaCl ₂ , Al ₂ (SO ₄ ) ₂ , Fe salt are selected so as to have the composition shown in Table 2, and the temperature and time of the hydrothermal synthesis conditions are adjusted. The hydrotalcite compounds 5 to 8 shown in Table 2 were obtained in the same manner as described above. Table 2 shows the physical properties of hydrotalcite compounds 5-8. The obtained hydrotalcite compounds could all be represented by the above formula.

[Production Example 9 of hydrotalcite compound]
In production example 3 of the hydrotalcite compound, except that the salt of MgCl ₂ , CaCl ₂ , Al ₂ (SO ₄ ) ₂ , Fe is selected so as to have the composition shown in Table 2, and the surface treatment agent type is changed. The hydrotalcite compound 9 shown in Table 2 was obtained in the same manner. Table 2 shows the physical properties of the hydrotalcite compound 9. In addition, the obtained hydrotalcite compound 9 could be represented by the above formula.

<Example of toner particle production>
In a four-necked container, 715 parts of ion-exchanged water and 850 parts of a 0.1 mol / L Na ₃ PO ₄ aqueous solution were added. K. The mixture was kept at 60 ° C. while stirring at 12,000 rpm using a homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.). To this, 68 parts of a 1.0 mol / L-CaCl ₂ aqueous solution was gradually added to prepare an aqueous dispersion medium containing a fine hardly water-soluble dispersion stabilizer Ca ₃ (PO ₄ ) ₂ .
Styrene 125 parts n-butyl acrylate 35 parts Copper phthalocyanine pigment (Pigment Blue 15: 3) 15 parts Polyester resin 10 parts (terephthalic acid-propylene oxide modified bisphenol A (2 mole adduct) (molar ratio = 51) : 50), acid value = 10 mg KOH / g, glass transition point = 70 ° C, Mw = 10500, Mw / Mn = 3.30)
Negative charge control agent (aluminum compound of 3,5-di-tert-butylsalicylic acid)
0.9 parts wax (Fischer-Tropsch wax, endothermic main peak temperature = 78 ° C.)
13 copies

  The above materials were stirred for 3 hours using an attritor (manufactured by Nippon Coke Kogyo Co., Ltd.), and each component was dispersed in the polymerizable monomer to prepare a monomer mixture. To the monomer mixture, 20.0 parts of 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanoate (a 50% toluene solution) as a polymerization initiator was added, and a polymerizable monomer was added. A composition was prepared. The polymerizable monomer composition was put into an aqueous dispersion medium, and granulated for 5 minutes while maintaining the rotational speed of the stirrer at 10,000 rpm. Thereafter, the high-speed stirrer was changed to a propeller stirrer, the internal temperature was raised to 70 ° C., and the reaction was allowed to proceed for 6 hours with slow stirring.

  Next, the temperature in the container was raised to 80 ° C. and maintained for 4 hours, and then gradually cooled to 30 ° C. at a cooling rate of 1 ° C. per minute to obtain a slurry. Dilute hydrochloric acid was added to the container containing the slurry to remove the dispersion stabilizer. Further, filtration, washing, and drying were performed to obtain polymer particles (toner base particles) having a weight average particle diameter (D4) of 6.5 μm. The average circularity of the toner base particles was 0.980.

<Example 1>
To 100 parts of the obtained toner base particles, the external additives listed in Table 3 were externally added with an FM mixer 10C (manufactured by Nippon Coke Kogyo Co., Ltd.) at a rotational speed of 3600 rpm for 10 minutes to obtain toner 1. . In addition, as the silica described as the other external additive, silica fine particles having a BET specific surface area of 85 m ² / g treated with hexamethyldisilazane and dimethyl silicone oil were used.
The formulation and various physical properties of Toner 1 are as described in Table 3.
An evaluation test described later was performed using the obtained toner. The evaluation results are shown in Table 4.

<Examples 2-12, Comparative Examples 1-8>
Toners 2 to 12 and 19 to 26 were obtained in the same manner as in Example 1 except that the formulations shown in Table 3 were used. Various physical properties of the toner are as shown in Table 3.
Table 4 shows the results of evaluation performed in the same manner as in Example 1.

<Examples 13 to 18>
First, organic inorganic composite fine particles and silica fine particles described in Table 3 were externally added to 100 parts of toner base particles with an FM mixer 10C (manufactured by Nippon Coke Kogyo Co., Ltd.) at a rotation speed of 3600 rpm for 10 minutes. Thereafter, the hydrotalcite compounds shown in Table 3 were added, and externally added for 5 minutes at a rotation speed of 3600 rpm using an FM mixer 10C (manufactured by Nippon Coke Industries, Ltd.). Toners 13 to 18 were obtained in the same manner as in Example 1 except that the above external addition method was used. Various physical properties of the toner are as shown in Table 3.
Table 4 shows the results of evaluation performed in the same manner as in Example 1.

<Evaluation test>
The toner was evaluated by modifying a commercially available laser printer LBP-7700C (manufactured by Canon) and a process cartridge and performing a durability test. The process speed was 300 mm / sec.

  This modified cartridge was modified so that the toner supply roller moved in the same direction at the contact portion with the toner carrying roller by changing / adding the gear inside the cartridge. The amount of penetration of the supply roller into the developing roller was 1.1 mm, and the peripheral speed of the supply roller with respect to the developing roller was adjusted to 160%. The product toner was extracted from the inside of the cartridge, cleaned by air blow, and then charged with 200 g of toner to be evaluated.

  The developer dropping was evaluated in a low-temperature and low-humidity environment where charge-up tends to occur. The fogging, image density stability, and fine line reproducibility were evaluated in a high-temperature and high-humidity environment where toner deterioration is likely to occur due to the influence of heat and humidity.

<Development dropout>
In a low-temperature and low-humidity environment (10 ° C./14% Rh), an endurance test for continuously outputting 3000 ruled line images with a printing ratio of 5% was performed to evaluate the development dropout.
A: No dropout occurs at the developing part B: Although slight dropout is observed on the drum, there is no problem on the image C: Dropping occurs on the image

<Evaluation of fogging>
The operation of outputting an image with a printing rate of 1% in a high temperature and high humidity environment (32.5 ° C./90% Rh) was repeated, and was allowed to stand overnight each time the output number reached 200. Thereafter, the process of outputting 200 sheets and allowing them to stand overnight was repeated. Finally, 5000 images were output and evaluated by the following method.

In the above-described image output test, images each having a white background portion were output one by one. Thereafter, with respect to the image having all the white background portions, the fogging is determined from the difference between the whiteness (reflectance Ds (%)) of the white background portion of the image having the white background portion and the whiteness (average reflectance Dr (%)) of the transfer paper. The concentration (%) (= Dr (%) − Ds (%)) was calculated. In addition, the whiteness was measured by “REFLECTMETER MODEL TC-6DS” (manufactured by Tokyo Denshoku Co., Ltd.). An amberlite filter was used as the filter. The following ranking was performed for the item with the most remarkable fogging.
A: The fog density is less than 0.5%.
B: The fog density is 0.5% or more and less than 1.5%.
C: The fog density is 1.5% or more and less than 3.0%.
D: The fog density is 3.0% or more.

<Image density stability>
In the image output test similar to the above-described fog evaluation, one solid image was output each time, and the density of each image was measured. Of the obtained image densities, the difference between the maximum density and the minimum density was determined and shown based on the following evaluation criteria. The image density was measured with a color reflection densitometer (manufactured by X-RITE 404 X-Rite).
A: The image density difference is 0.1 or less.
B: The image density difference is larger than 0.1 and not larger than 0.3.
C: The image density difference is greater than 0.3 and less than or equal to 0.5.
D: Image density difference is larger than 0.5, or image streaks are generated on the image due to streaks of the developing sleeve.

<Thin wire reproducibility>
The fine line reproducibility was evaluated from the viewpoint of image quality. In the above image output, after outputting 2000 images, an image in which a grid pattern with a line width of 3 pixels was printed on the entire surface of A4 paper (print area ratio 4%) was printed, and fine line reproducibility was evaluated according to the following evaluation criteria. . The line width of 3 pixels is theoretically 127 μm. The line width of the image was measured with a microscope VK-8500 (manufactured by Keyence). The line width was measured by randomly selecting 5 points, and the following L was defined as the fine line reproducibility index when the average value of 3 points excluding the minimum value and the maximum value was d (μm). Smaller L indicates better fine line reproducibility.
L (μm) = | 127−d |
A: L is 0 μm or more and less than 5 μm.
B: L is 5 μm or more and less than 15 μm.
C: L is 15 μm or more and less than 30 μm.
D: L is 30 μm or more.

DESCRIPTION OF SYMBOLS 1 Photosensitive drum 4 Developing unit 7 Process cartridge 13 Photosensitive unit 15 Developing chamber 17 Developing roller (toner carrier)
18 Toner storage chamber 20 Toner supply roller (toner supply member)
22 Agitating and conveying member 30 Developing opening 80 Toner 100 Image forming apparatus

Claims (6)

Toner base particles and toner having organic-inorganic composite fine particles and hydrotalcite compounds on the surface of the toner base particles,
The organic-inorganic composite fine particles have a structure in which inorganic fine particles are embedded in vinyl resin particles,
The inorganic fine particles are exposed on the surface of the organic-inorganic composite fine particles, and the abundance of the inorganic fine particles on the surface of the organic-inorganic composite fine particles is 20% or more and 70% or less,
The organic-inorganic composite fine particles and the hydrotalcite compound have a surface potential of −900 V or more and −400 V or less when charged by corona charging, and a time constant τ when the surface potential decays is 200 seconds or more and 2000 A toner characterized by being less than a second.   2. The toner according to claim 1, wherein the content of the organic-inorganic composite fine particles is 0.5 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the toner base particles.   The toner according to claim 1 or 2, wherein the organic-inorganic composite fine particles have a shape factor SF-1 of 100 or more and 150 or less and a shape factor SF-2 of 103 or more and 120 or less.   The toner according to any one of claims 1 to 3, wherein the organic-inorganic composite fine particles have a number average particle diameter of 50 nm or more and 400 nm or less.   The toner according to claim 1, wherein the hydrotalcite compound has a number average particle diameter of 100 nm or more and 1000 nm or less. When the number average particle size of the organic-inorganic composite fine particles is “A” and the number average particle size of the hydrotalcite compound is “B”, B / A is 1.5 or more and 10.0 or less. Item 6. The toner according to any one of Items 1 to 5.