JP2010243693A - Toner and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide toner that has stable electrostatic chargeability and obtains high quality images during long-time use and in various environments by suppressing toner scattering and fogging, and to provide an image forming method using the same. <P>SOLUTION: The toner contains a binder resin, a colorant, and a charge controlling agent and has particle surfaces coated with an external additive, and the charge controlling agent is a cyclic phenol sulfide expressed by general formula (1) and selected from thiacalixarenes, sulfinated thiacalixarenes, and sulfonated thiacalixarene, and the external additive contains at least two or more kinds of inorganic particulates having a number average primary particles size of 5 to <50 nm and having a number average primary particle size of 50 to 300 nm. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a toner used in an electrophotographic image forming method and a manufacturing method thereof.

  In recent years, electrophotographic image forming apparatuses have been used as ordinary copying machines and printers for printing office documents or as simple copies, to the field of producing printed materials for office use, specifically electronic data. Since variable information can be printed easily, the application has expanded to the on-demand printing (POD) market, which is a light printing area, and several copiers and printers have been installed in the office. As a whole, the amount of power consumption has increased.

  In the POD market, since a value is required for the printed matter, not for copying, it is required to form a high-quality image as the printed matter.

  Conventionally, it is known to treat deterioration during durability by treating silica having a large particle size distribution as an external additive in a pulverized toner or a polymerized toner (see, for example, Patent Document 1).

  On the other hand, conventional negatively chargeable toners, in addition to the charging function of the base material, use an external additive such as hydrophobic silica having a relatively small particle size to improve the chargeability in addition to improving the fluidity of the toner. (For example, refer to Patent Documents 2 and 3). However, when a large-diameter silica and a small-diameter silica are used in combination, the electrostatic repulsion force makes it difficult for the large-diameter particles to adhere and immobilize uniformly on the surface of the toner particles. There is a problem that it becomes difficult to maintain the electric restraining force, and these external additives are detached from the toner surface during the endurance, and cause toner scattering and fogging. In addition, due to the separation and release of these external additives, the external additives migrate to the surface of a functional member such as a charge imparting member such as a carrier (carrier, developing roller, regulating blade, etc.), a photoconductor, or an intermediate transfer belt. In addition, it becomes difficult to impart stable chargeability and maintain high-quality images during durability and in various environments. (Generation of image noise due to deterioration of chargeability during endurance or filming on the functional member). In particular, so-called low-temperature fixing toners, which are particularly demanding for energy saving in recent years, have a low glass transition temperature of the binder resin, and in addition to the above problems, embedding of external additives in the toner is remarkable due to stress during durability. As a result, it becomes difficult to impart more stable chargeability and secure a high-quality image.

JP 2007-99582 A Japanese Patent Laid-Open No. 2002-214827 JP 2003-140402 A

  The present invention has been made based on the circumstances as described above, and its purpose is to suppress toner scattering and fogging, to provide stable electric resistance in durability and in various environments, and to obtain a high-quality image. It is an object of the present invention to provide a toner and a manufacturing method thereof.

  In the present invention, the use of at least two kinds of external additives having specific particle diameters together with the toner particles containing a charge control agent having a specific structure in the toner particles can greatly It is intended to make an improvement.

  That is, the present invention is achieved by having the following configuration.

  1. A toner obtained by coating a toner particle containing at least a binder resin, a colorant, and a charge control agent and the surface thereof with an external additive, wherein the charge control agent is represented by the following general formula (1). A cyclic phenol sulfide selected from calixarene, sulfinylated thiacalixarene and sulfonylated thiacalixarene, wherein the external additive has inorganic particles having a number average primary particle size of 5 nm or more and less than 50, and a number average primary particle size of 50 nm. A toner comprising at least two types of inorganic particles having a particle size of 300 nm or less.

(Wherein, X represents S, SO or SO _2, Z is .n represents a hydrogen atom, an alkyl group, a substituted alkyl group, an aralkyl group, an acyl group, or an alkoxycarbonyl group is an integer of 3-9, Y is a hydrocarbon group, a halogenated hydrocarbon group, a halogen atom, —SO ₄ R ¹ or —SO ₃ R ² , R ¹ and R ² represent a hydrogen atom, a hydrocarbon group, or a metal element, Y may be the same or different.)
2. 2. The toner according to 1 above, wherein the inorganic particles having a number average primary particle size of 50 nm to 300 nm are spherical silica particles.

  3. 3. The toner according to 1 or 2, wherein the toner has a volume-based median diameter of 2.0 μm or more and 8.0 μm or less and an average circularity of 0.940 to 0.995.

  4). 4. The toner according to any one of items 1 to 3, wherein the toner has a softening point temperature of 121 ° C. or lower and a glass transition temperature of 55 ° C. or lower.

  5. An image forming method for forming a toner image using at least a black toner and a color toner, wherein the toner is the toner described in any one of 1 to 4 above.

  According to the toner of the present invention, toner particles containing a binder resin, a colorant, and a charge control agent and the surface thereof are coated with an external additive, the charge control agent having the general formula ( 1) a cyclic phenol sulfide selected from thiacalixarene, sulfinylated thiacalixarene, and sulfonylated thiacalixarene represented by 1), wherein the external additive has a number average primary particle size of 5 to less than 50 nm and fine particles Toner particles containing at least two kinds of inorganic particles having a primary particle size of 50 to 300 nm, and containing the charge control agent in the toner particles, even if a large external additive is treated together The microscopic resistance adjusting function of the surface works, and an appropriate adhesion state can be maintained for both the small diameter and large diameter external additives without causing electrostatic repulsion. That is, the small diameter external additive uniformly adheres to the vicinity of the toner particle surface and the large diameter external additive does not adhere to the toner particle surface without causing electrostatic aggregation between the large diameter external additive and the small diameter external additive. It is possible to interspers with an appropriate adhesive force without agglomeration. As a result, in the actual machine, the small-diameter external additive can be prevented from being detached and released by adhering to the toner particle surface with a relatively strong force, and the large-diameter external additive is small-diameter external additive. As a result, a moderate amount of toner migrates from the particle surface onto the photoreceptor or transfer belt during the development or transfer process, resulting in improved developability, transferability and cleaning performance. It becomes possible to improve. On the other hand, by being attached and restrained uniformly and with an appropriate force on the toner surface, a charge imparting member (carrier, developing roller, regulating blade, etc.) such as a carrier by detachment or separation, a photoreceptor, an intermediate transfer belt, etc. Since it does not cause contamination, toner scattering and fogging are suppressed, and stable durability can be imparted and high-quality images are maintained during durability and in various environments.

1 is a schematic diagram illustrating an example of a non-magnetic one-component developing type image forming apparatus. FIG. 2 is a cross-sectional view of a developing device that can be mounted on a non-magnetic one-component developing type image forming apparatus. 1 is a schematic diagram illustrating an example of a two-component developing type image forming apparatus.

  Hereinafter, the present invention will be specifically described.

  The toner of the present invention is a toner composed of toner particles containing a colorant and a charge control agent, and contains at least two types of inorganic particles as external additives, one of which is a number average. The primary particle size is 5 nm or more and less than 50 nm, and the other is a number average primary particle size of 50 nm or more and 300 nm or less, and the charge control agent is thiacalix represented by the general formula (1) It is a cyclic phenol sulfide selected from arenes, sulfinylated thiacalixarenes, and sulfonylated thiacalixarenes. Specific examples are shown in Table 1 below.

(Wherein, X represents S, SO or SO _2, Z is .n represents a hydrogen atom, an alkyl group, a substituted alkyl group, an aralkyl group, an acyl group, or an alkoxycarbonyl group is an integer of 3-9, Y is a hydrocarbon group, a halogenated hydrocarbon group, a halogen atom, —SO ₄ R ¹ or —SO ₃ R ² , R ¹ and R ² represent a hydrogen atom, a hydrocarbon group, or a metal element, Y may be the same or different)
First, the cyclic phenol sulfide represented by the general formula (1) contained in the toner according to the present invention will be described.

  Specific examples of the hydrocarbon group include, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, 2-methylbutyl, n-hexyl, Isohexyl, 3-methylpentyl, ethylptyl, n-heptyl, 2-methylhexyl, n-octyl, isooctyl, tert-octyl, 2-ethylhexyl, 3-methylheptyl, n-nonyl, isononyl, 1-methyloctyl, ethylheptyl , N-decyl, 1-methylnonyl, n-undecyl, 1,1-dimethylnonyl, n-dodecyl, n-tetradecyl, n-hebutadecyl, alkyl groups such as n-octadecyl group, and polymers of ethylene, propylene and butylene Or their copolymers Ri hydrocarbon group made.

  Suitable specific examples of the unsaturated aliphatic hydrocarbon group include, for example, vinyl, aryl, isopropenyl, 2-butenyl, 2-methylallyl, 1,1-dimethylallyl, 3-methyl-2-butenyl, 3-methyl- Examples thereof include alkenyl such as 3-butenyl, 4-pentenyl, hexenyl, octenyl, nonenyl and decenyl groups, alkynyl groups, and groups composed of polymers of acetylene, butadiene and isopropylene or copolymers thereof. Specific examples of the alicyclic hydrocarbon group include, for example, cyclobrovir, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 4-ethylcyclohexyl, 2-methylcyclooctyl, Examples thereof include cycloalkyl such as cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, cyclooctenyl, 4-methylcyclohexenyl, 4-ethylcyclohexenyl group, cycloalkenyl, cycloalkynyl group and the like.

  Suitable examples of the alicyclic-aliphatic hydrocarbon group include, for example, cyclopropylethyl, cyclobutylethyl, cyclopentylethyl, cyclohexylmethyl, cyclohexylethyl, cycloheptylmethyl, cyclooctylethyl, 3-methylcyclohexylpropyl, 4-methylcyclohexylethyl, 4-ethylcyclohexylethyl, 2-methylcyclooctylethyl, cyclopropenylbutyl, cyclobutenylethyl, cyclopentenylethyl, cyclohexenylmethyl, cycloheptenylmethyl, cyclooctenylethyl, 4-methylcyclohexyl Alkyl, alkenyl, alkynyl groups, etc. substituted with cycloalkyl, cycloalkenyl, cycloalkynyl groups, etc. such as ceninolepropyl, 4-ethylcyclohexenylpentyl group, etc. It is below.

  Suitable examples of the aromatic hydrocarbon group include aryl groups such as phenyl and naphthyl groups, 4-methylphenyl, 3,4-dimethylphenyl, 3,4,5-trimethylphenyl, 2-ethylphenyl, n -Butylphenyl, tert-butylphenyl, amylphenyl, hexylphenyl, nonylphenyl, 2-tert-butyl-5-methylphenyl, cyclohexylphenyl, cresyl, oxyethylcresyl, 2-methoxy-4-tert-butylphenyl, Examples include alkylaryl such as dodecylphenyl group, alkenylaryl, alkynylaryl group and the like. The alkyl part of the alkylaryl group, the alkenyl part of the alkenylaryl group, and the alkynyl part of the alkynylaryl group may have a cyclic structure.

Specific examples of the aromatic-aliphatic hydrocarbon group include benzyl, 1-phenylethyl, 2-phenylethyl, 2-phenylpropyl, 3-phenylpropyl, 4-phenylbutyl, 5-phenylpentyl, 6 Aralkyl such as -phenylhexyl, 1- (4-methylphenyl) ethyl, 2- (4-methylphenyl) ethyl, 2-methylbenzyl, 1,1-dimethyl-2-phenylethyl group, aralkenyl, aralkynyl group, etc. Can be mentioned. The alkyl part of the aralkyl group, the alkenyl part of the aralkenyl group, and the alkynyl part of the aralkynyl group may have a cyclic structure. The halogenated hydrocarbon is preferably one in which the above hydrocarbon group is substituted with a halogen, and the type of halogen may be any of a fluorinated product, a chlorinated product, a brominated product, and an iodinated product. The halogen atom may be any of a fluorinated product, a chlorinated product, a brominated product, and an iodinated product. R ^{1 to} R ⁵ are hydrogen atoms or hydrocarbon groups, and R ⁶ and R ⁷ are hydrogen atoms, hydrocarbon groups, or metals. As the hydrocarbon group, the above hydrocarbon groups can be applied.

In the general formula (1), the metal of R ¹ and R ² , that is, the metal of the sulfate metal salt or the sulfonate metal salt of Y is not particularly limited, but an alkali metal is preferable. Examples of the alkali metal include sodium, potassium, rubidium, cesium, frangium and the like, but sodium is preferable. Moreover, in General formula (1), n is an integer of 4-6, However, Preferably it is 4. The cyclic phenol sulfide of the general formula (1) is a thiacalixarene in which X in the general formula (1) is S, a sulfinylated thiacalixarene in which X in the general formula (1) is SO, or the general formula (1 ) Is a sulfonylated thiacalixarene in which X is SO ₂ .

  Thiacalixarene cyclic phenol sulfide is generally referred to as thiacalixarene and can be produced by a known method (Tetrahedron, 53, 10689 (1997), Tetrahedron Lett. 38, 3971 (1997), JP-A-9-227553, JP-A-10-77282, JP-A-10-81680, JP-A-10-168078, JP-A-11-49770, JP-A-11-255766, JP-A-2001-2001. No. 181278, Japanese Patent Laid-Open No. 2000-273096, and Japanese Patent No. 3323570). Further, the residue Z in the general formula (1) can be introduced by reacting these calixarenes with an alkylating agent, an acylating agent or an alkoxycarbonylating agent in the presence of a base catalyst (Japanese Patent Laid-Open No. Hei. 10-1608078 and JP-A-11-152284). Sulfinylated thiacalixarenes as well as sulfonylated thiacalixarenes can also be produced by known methods (see WO 98/9959). In the present invention, only one type of charge control agent represented by the general formula (1) may be used, or two or more types may be used in combination.

  The charge control agent is preferably used by adjusting the volume average particle diameter to 0.05 to 5 μm.

  In particular, when used in a wet granulation method such as suspension polymerization or emulsion polymerization aggregation method, it is used at 0.05 to 1 μm, more preferably 0.05 to 0.5 μm.

  The addition amount is 0.05 to 5 parts by mass, preferably 0.1 to 2 parts by mass, and more preferably 0.2 to 1 part by mass with respect to the toner particles. It may be contained in the entire toner particle or may be localized on the surface.

(External additive particles)
The present invention is characterized by containing at least inorganic fine particles having a number average primary particle size of 5 nm or more and less than 50 nm and inorganic fine particles having a number average primary particle size of 50 nm or more and 300 nm or less.

  As the inorganic fine particles having a number average primary particle size of 5 nm or more and less than 50 nm as external additives usable in the present invention, various inorganic oxides, nitrides, borides and the like can be suitably used. Specifically, examples of the inorganic oxide include silica, alumina, titania, zirconia, zinc oxide, chromium oxide, cerium oxide, antimony oxide, tungsten oxide, tin oxide, tellurium oxide, manganese oxide, and boron oxide. . Examples of the carbide include silicon carbide, boron carbide, and titanium carbide. Examples of the nitride include silicon nitride, titanium nitride, and boron nitride. Particularly preferable examples include ultrafine silica, alumina, titania and composite oxide particles having a number average primary particle size of 5 nm or more and less than 50 nm produced by a vapor phase method. The composite oxide particles preferably contain a silicon atom and at least one atom of a titanium atom, an aluminum atom, a zirconium atom, and a calcium atom. In addition, anatase type, rutile type, and amorphous titania particles produced by the sulfuric acid method or the like can also be suitably used. The addition amount is 0.1 to 5.0 parts by mass, preferably 0.5 to 3 parts by mass with respect to the toner.

  On the other hand, as the inorganic fine particles having a number average primary particle size of 5 nm or more and less than 50 nm, synthetic silica fine particles are preferable. Synthetic silica is produced by combustion method silica obtained by burning a silane compound (ie fumed silica), deflagration silica obtained by explosively burning metal silicon powder, sodium silicate and mineral acid. Wet silica obtained by neutralization reaction (of which, synthesized under alkaline conditions is precipitated silica, and synthesized under acidic conditions is gel silica), sol-gel silica obtained by hydrolysis of hydrocarbyloxysilane (so-called Stober) Law). In the present invention, any type can be used. In particular, silica produced by a sol-gel method having a uniform particle size and shape can be preferably used. The addition amount is 0.1 to 8.0 parts by mass, preferably 0.5 to 5 parts by mass with respect to the toner.

  These external additive compounds are preferably surface-treated with a known treatment agent such as a coupling agent, and specific treatment agents for surface treatment include the following.

  Silane coupling agent, titanate coupling agent, silicone oil, silicone varnish, fluorine silane coupling agent, fluorine silicone oil, amino group / quaternary ammonium salt-containing coupling agent, modified silicone oil and the like.

  In order to further improve the cleaning property and transfer property, it is also possible to use a higher fatty acid metal salt called a so-called lubricant in combination. Specific examples of the higher fatty acid metal salt include the following. That is, salts of zinc stearate, aluminum, copper, magnesium, calcium, etc., zinc oleate, salts of manganese, iron, copper, magnesium, etc., zinc palmitate, salts of copper, magnesium, calcium, etc., linoleic acid There are salts of zinc, calcium and the like, and zinc and calcium of ricinoleic acid.

  In addition, titanate compounds such as strontium titanate, calcium titanate, magnesium titanate, and barium titanate can be used in combination. In addition to the inorganic fine particles, known organic fine particles having an average primary particle diameter of about 10 to 2000 nm can be used. Specifically, a small diameter made of a homopolymer such as styrene or methyl methacrylate or a copolymer thereof. External additive particles can be used.

  The amount of these external additives added to the toner is preferably 0.3 to 10.0 parts by mass as the total amount of the above-mentioned external additives. More preferably, it is 0.5-5.0 mass%. Moreover, as an addition method of an external additive, the method of adding using various well-known mixing apparatuses, such as a Turbuler mixer, a Henschel mixer, a Nauta mixer, and a V-type mixer, is mentioned.

  The toner used in the present invention preferably has a volume-based median diameter (D50v) of 2 μm or more and 8 μm or less. By setting the volume reference median diameter in the above range, for example, it is possible to faithfully reproduce a very minute dot image at a level of 1200 dpi (dpi; number of dots per inch (2.54 cm)).

  By setting the volume-based median diameter to a small diameter within the above range, it is possible to faithfully reproduce the dot image constituting the photographic image and the like, so that a high-definition color photographic image equivalent to or higher than the printed image is formed. be able to. In particular, in the printing field called “on-demand printing” where print orders are received at several hundred to several thousand levels, full-color high-quality prints containing high-definition photographic images can be quickly delivered to users. .

  The volume-based median diameter (D50v diameter) of the toner can be measured and calculated using an apparatus in which a computer system for data processing is connected to “Multisizer 3 (manufactured by Beckman Coulter)”.

  As a measurement procedure, 0.02 g of toner is blended with 20 ml of a surfactant solution (for example, a surfactant solution obtained by diluting a neutral detergent containing a surfactant component 10 times with pure water for the purpose of dispersing the toner). After that, ultrasonic dispersion is performed for 1 minute to prepare a toner dispersion. This toner dispersion is poured into a beaker containing “ISOTONII” (manufactured by Beckman Coulter) in the sample stand with a pipette until the measured concentration reaches 5 to 10%, and the measuring machine count is set to 2500 pieces. To measure. The aperture diameter of “Multisizer 3” is 50 μm.

  The toner used in the present invention preferably has a coefficient of variation (CV value) in the volume-based particle size distribution of 2% to 21%, more preferably 5% to 15%.

  The coefficient of variation (CV value) in the volume-based particle size distribution represents the degree of dispersion in the particle size distribution of the toner particles on the volume basis, and is defined by the following equation.

CV value (%) = (standard deviation in number particle size distribution) / (median diameter (D50v) in number particle size distribution) × 100
The smaller the CV value, the sharper the particle size distribution, and the larger the toner particle size. In other words, since toners with uniform sizes can be obtained, it is possible to reproduce a fine dot image and fine lines required for digital image formation with higher accuracy. Further, when printing a photographic image, it is possible to create a high-quality photographic image having an image quality produced by printing ink or higher by using small-diameter toner having a uniform size.

  The toner used in the present invention preferably has an average circularity (average value of shape factor) represented by the following formula of 0.940 to 0.995, preferably 0.950 to 0.995.

Average circularity = (circle circumference calculated from equivalent circle diameter) / (perimeter of particle projection image)
The method for measuring the average circularity is not particularly limited. For example, the toner particles are magnified 500 times with an electron microscope, a photograph is taken, and an image analysis apparatus is used from the electron micrograph image. The average circularity can be calculated by measuring the circularity of 500 toner particles and calculating the arithmetic average value thereof.

  By setting the average circularity of the toner used in the present invention to 0.940 to 0.995, the shape of the toner used for image formation is uniform to some extent. Concerns about the impact on That is, the toner particles have the same shape so that, for example, there is no variation in the melting and fixing of the toner during fixing, the adhesion of the external additive is equalized, and the effects of the external additive particles can be made uniform. Become. Furthermore, the durability against stress during image formation is also made uniform. With these effects, it is expected that a good quality toner image with no variation in color tone or density can be obtained.

  The toner according to the present invention preferably has a softening point temperature (Tsp) of 121 ° C. or lower, more preferably 70 ° C. or higher and 100 ° C. or lower.

  By setting the softening point of the toner within the above range, the toner image can be fixed at a temperature lower than that of the prior art, and environmentally friendly image formation that realizes reduction in power consumption is enabled. Further, it is also preferable for developing stable fixing performance even in the POD field where the present invention can be suitably used.

The softening point of the toner can be controlled by, for example, the following methods alone or in combination. That is,
(1) The type and composition ratio of monomers used for resin formation are adjusted.
(2) The molecular weight of the resin is adjusted according to the type and amount of chain transfer agent.
(3) Adjust the type and amount of wax.

Further, the method for measuring the softening point temperature of the toner is specifically “Flow Tester CFT-500 (manufactured by Shimadzu Corporation)”, molded into a columnar shape with a height of 10 mm, and at a heating rate of 6 ° C./min. While being heated, a pressure of 1.96 × 10 ⁶ Pa is applied from the plunger, and the pressure is pushed out from a nozzle having a diameter of 1 mm and a length of 1 mm. Thereby, a curve between the plunger drop amount and temperature of the flow tester (softening flow curve) ), And the temperature at the first outflow is the melting start temperature, and the temperature for the drop of 5 mm is the softening point temperature.

  The toner according to the present invention preferably has a glass transition temperature (Tg) of 55 ° C. or lower, more preferably 50 ° C. or lower.

  By setting the glass transition temperature of the toner within the above range, the toner image can be fixed at a temperature lower than that of the prior art, and environmentally friendly image formation that realizes a reduction in power consumption is enabled. Further, it is also preferable for developing stable fixing performance even in the POD field where the present invention can be suitably used.

  The glass transition temperature of the toner of the present invention can be measured using a DSC-7 differential scanning calorimeter (manufactured by PerkinElmer).

  As a measurement procedure, toner 4.5 mg to 5.0 mg is precisely weighed to two decimal places, sealed in an aluminum pan (KITNO.0219-0041), and set in a DSC-7 sample holder. The reference used an empty aluminum pan. The measurement conditions were a measurement temperature of 0 ° C. to 200 ° C., a temperature increase rate of 10 ° C./min, a temperature decrease rate of 10 ° C./min, and heat-cool-heat temperature control. Analysis was performed based on the data in Heat.

  The glass transition temperature draws an extension of the baseline before the rise of the first endothermic peak and a tangent line indicating the maximum slope between the rise of the first peak and the peak apex, and the intersection is taken as the glass transition point. Show.

  Next, a method for producing the toner used in the present invention will be described.

  The toner used in the present invention is composed of particles (hereinafter also referred to as colored particles) containing at least a resin and a colorant. The colored particles constituting the toner used in the present invention (base particles before the external addition treatment) are not particularly limited, and can be prepared by a conventional toner manufacturing method. . That is, by a so-called pulverization method for producing a toner through kneading, pulverization, and classification steps, or by a so-called polymerization method in which a polymerizable monomer is polymerized and particles are formed while controlling the shape and size at the same time. There is a toner manufacturing method. Examples of the toner production method using a polymerization method include an emulsion polymerization method, a suspension polymerization method, and a polyester elongation method. As described above, the toner manufacturing method using the polymerization method can control the shape and size in the particle forming step. The charge control agent may be contained inside the toner particles or may be localized on the surface. In the case of being localized on the surface, in the wet method, after the toner particles are formed, (1) only the charge control agent is formed on the surface layer, (2) together with the resin component, and (3) a resin containing the charge control agent. It is preferable to attach or fix the fine particles.

  In the dry method, it is preferable to fix the toner surface to the toner surface by a thermal force or a mechanical impact force. As a specific apparatus, a Henschel mixer, a hybridization system, a surfing system, a mechanofusion system, or the like can be preferably used.

  When the toner is produced by a pulverization method, it is preferable to produce the toner while maintaining the temperature of the kneaded material at 130 ° C. or lower. This is because when the temperature applied to the kneaded product exceeds 130 ° C., the colorant in the kneaded product may change in the agglomerated state due to the action of heat applied to the kneaded product, and the uniform aggregated state may not be maintained. Because. If variations occur in the aggregated state, the color tone of the produced toner varies, which may cause color turbidity.

  Next, the resin, wax, colorant and the like constituting the toner used in the present invention will be described with specific examples.

  First, the resin forming the toner used in the present invention is not particularly limited, but a polymer formed by polymerizing a polymerizable monomer called a vinyl monomer described below. Is a typical example. The polymer constituting the resin that can be used in the present invention is a polymer obtained by polymerizing at least one polymerizable monomer, and these vinyl monomers are used alone. Or it is the polymer produced combining multiple types.

Specific examples of vinyl polymerizable monomers are shown below.
(1) Styrene or styrene derivatives Styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-tert- Butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, etc. (2) Methacrylate derivatives Methyl methacrylate, methacryl Ethyl acetate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, diethyl methacrylate (3) Acrylic acid ester derivatives Methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate, phenyl acrylate, etc. (4) olefins Ethylene, propylene, isobutylene, etc. (5) Vinyl esters Vinyl propionate, vinyl acetate, vinyl benzoate, etc. (6) Vinyl ether (7) Vinyl ketones Vinyl methyl ketone, vinyl ethyl ketone, vinyl hexyl ketone, etc. (8) N-vinyl compounds N-vinyl carbazole, N-vinyl indole (9) Others Vinyl compounds such as vinyl naphthalene and vinyl pyridine, acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, acrylamide, etc. In addition, a binder resin for the toner used in the present invention is used. As the vinyl-based polymerizable monomer constituting, those having an ionic dissociation group shown below can be used. For example, there are those having a functional group such as a carboxyl group, a sulfonic acid group, and a phosphoric acid group in the side chain of the monomer.

  First, those having a carboxyl group include acrylic acid, methacrylic acid, maleic acid, itaconic acid, cinnamic acid, fumaric acid, maleic acid monoalkyl ester, itaconic acid monoalkyl ester, and the like. Examples of those having a sulfonic acid group include styrene sulfonic acid, allyl sulfosuccinic acid, and 2-acrylamido-2-methylpropane sulfonic acid. Examples of those having a phosphoric acid group include acid phosphooxyethyl methacrylate. is there.

  Moreover, it is also possible to produce a resin having a crosslinked structure by using the following polyfunctional vinyls. Specific examples of polyfunctional vinyls are shown below.

Divinylbenzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol diacrylate, and the like.
[Colorant]
As the colorant constituting the toner of the present invention, carbon black, a magnetic material, a dye, a pigment, and the like can be arbitrarily used. Examples of the carbon black include channel black, furnace black, acetylene black, thermal black, and lamp black. Is used. Magnetic materials include ferromagnetic metals such as iron, nickel and cobalt, alloys containing these metals, compounds of ferromagnetic metals such as ferrite and magnetite, alloys that do not contain ferromagnetic metals but exhibit ferromagnetism by heat treatment, For example, a kind of alloy called Heusler alloy such as manganese-copper-aluminum and manganese-copper-tin, chromium dioxide, and the like can be used.

  Examples of the black colorant include carbon black such as furnace black, channel black, acetylene black, thermal black, and lamp black, and magnetic powder such as magnetite and ferrite.

  As colorants for color toners, pigments or dyes made of organic compounds are used.

  Examples of the colorant for magenta or red include C.I. I. Pigment Red 1, 2, 3, 5, 6, 7, 15, 16, 48: 1, 53: 1, 57: 1, 60, 63, 64, the same 68, 81, 83, 87, 88, 89, 90, 112, 114, 122, 123, 139, 144, 149, 150, 163, 166, 170, 177, 178, 184, 202, 206, 207, 209, 222, 238, 269, etc.

  Examples of the colorant for orange or yellow include C.I. I. Pigment Orange 31 and 43, C.I. I. Pigment Yellow 12, 14, 15, 17, 74, 83, 93, 94, 138, 155, 162, 180, 185, and the like.

  Further, as a colorant for green or cyan, C.I. I. Pigment Blue 2, 3, 15, 15, 15: 2, 15: 3, 15: 4, 16, 17, 17, 60, 62, 66, C.I. I. Pigment Green 7 etc.

  Examples of the dye include C.I. I. Solvent Red 1, 49, 52, 58, 63, 111, 122, C.I. I. Solvent Yellow 2, 6, 14, 15, 16, 19, 21, 21, 33, 44, 56, 61, 77, 79, 80, 81, 82, the same 93, 98, 103, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 60, 70, 93, 95, etc.

  These colorants can be used alone or in combination of two or more as required. The addition amount of the colorant is set in the range of 1 to 30% by mass, preferably 2 to 20% by mass with respect to the whole toner.

Next, the waxes contained in the toner used in the present invention include the following.
(1) Polyolefin wax Polyethylene wax, polypropylene wax, etc. (2) Long chain hydrocarbon wax, paraffin wax, sazol wax, etc. (3) Dialkyl ketone wax, distearyl ketone, etc. (4) Ester wax Carnauba wax, Montan Wax, trimethylolpropane tribehenate, pentaerythritol tetramyristate, pentaerythritol tetrastearate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerol tribehenate, 1,18-octadecanediol di Stearate, trimellitic trimellitic acid, distearyl maleate, etc. (5) Amide wax Ethylenediamine dibehenyl amide, trimellitic acid triste The melting point of Riruamido such as wax is usually from 40 to 125 ° C., preferably from 50 to 120 ° C., more preferably from 60 to 90 ° C.. By setting the melting point within the above range, the heat-resistant storage stability of the toner is ensured, and stable toner image formation can be performed without causing cold offset or the like even when fixing at a low temperature. Further, the wax content in the toner is preferably 1% by mass to 30% by mass, and more preferably 5% by mass to 20% by mass.
<Developer>
The toner of the present invention may be used, for example, as a one-component magnetic toner containing a magnetic material, as a two-component developer mixed with a so-called carrier, or as a non-magnetic toner alone. Any of these can be suitably used.

  In the toner of the present invention, when used as a two-component developer mixed with a carrier, it is possible to suppress the occurrence of toner filming (carrier contamination) on the carrier, and when used as a one-component developer, The occurrence of toner filming on the frictional charging member of the apparatus can be suppressed.

  As the carrier constituting the two-component developer, magnetic particles made of conventionally known materials such as metals such as iron, ferrite, and magnetite, and alloys of these metals with metals such as aluminum and lead can be used. It is particularly preferable to use ferrite particles.

  The carrier preferably has a volume average particle diameter of 15 to 100 μm, more preferably 20 to 50 μm. The volume average particle diameter of the carrier can be typically measured by a laser diffraction particle size distribution measuring apparatus “HELOS” (manufactured by SYMPATEC) equipped with a wet disperser.

As the carrier, it is preferable to use a carrier coated with a resin, or a so-called resin dispersion type carrier in which magnetic particles are dispersed in a resin. The resin composition for coating is not particularly limited, and for example, olefin resin, styrene resin, styrene-acrylic resin, silicone resin, ester resin, or fluorine-containing polymer resin is used. Moreover, it does not specifically limit as resin for comprising a resin dispersion type carrier, A well-known thing can be used, For example, a styrene-acrylic resin, a polyester resin, a fluorine resin, a phenol resin etc. are used. be able to.
<Image forming method>
The above toner can be suitably used in an image forming method including a fixing step by a contact or non-contact heating method. Specifically, as an image forming method, an electrostatic latent image formed electrostatically on, for example, an image carrier using the toner as described above, and a developer in a developing device by a friction charging member. By revealing the toner image by charging to obtain a toner image, transferring the toner image to the recording material, and then fixing the toner image transferred on the recording material to the recording material by a contact heating type fixing process, A visible image is obtained.
<Fixing method>
As a suitable fixing method using the toner of the present invention, a so-called contact heating method can be mentioned. Examples of the contact heating method include a heat pressure fixing method, a heat roll fixing method, and a pressure contact heat fixing method in which fixing is performed by a rotating pressure member including a fixedly arranged heating body.

  In the fixing method of the hot roll fixing method, usually, an upper roller provided with a heat source inside a metal cylinder made of iron or aluminum whose surface is coated with fluororesin, etc., and a lower roller formed of silicone rubber or the like Is used.

  As the heat source, a linear heater is used, and the surface temperature of the upper roller is heated to about 120 to 200 ° C. by this heater. A pressure is applied between the upper roller and the lower roller, and the lower roller is deformed by this pressure, so that a so-called nip is formed in the deformed portion. The width of the nip is 1 to 10 mm, preferably 1.5 to 7 mm. The fixing linear velocity is preferably 40 mm / sec to 600 mm / sec. If the nip width is too small, heat cannot be uniformly applied to the toner, and uneven fixing may occur. On the other hand, if the nip width is too large, it is contained in the toner particles. The melting of the polyester resin is accelerated, and there is a possibility that fixing offset occurs.

  According to the toner having the above-described configuration, the toner particles constituting the toner are toner particles containing a binder resin, a colorant, and a charge control agent, and a toner obtained by coating the surface with an external additive. In addition, the external additive contains at least two kinds of inorganic fine particles of 5 to less than 50 nm and inorganic fine particles of 50 to 300 nm and further contains the charge control agent of the present invention. It is possible to stabilize the chargeability in a wet environment.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to said aspect, A various change can be added.

  The image forming method according to the present invention is an image forming method for forming a toner image using color toner and black toner. In other words, it is applied to a two-component developing type image forming method using a two-component developer mixed with a carrier and a one-component developing type color image forming method using a non-magnetic one-component developer not using a carrier. can do.

  Among these, in the image formation of the non-magnetic one-component development method in which image formation is performed without using a carrier, the toner is rubbed and pressed against the charging member and the developing roller surface during image formation to be charged. As described above, in the image formation by the non-magnetic one-component development system, since the dedicated means for charging the toner is not provided, the structure of the developing device can be simplified, which is advantageous for realizing a compact image forming apparatus. By using the configuration according to the present invention, a non-magnetic one-component development type image forming method using a compact full-color image forming apparatus can balance a black image and a color image even in a space-limited working environment. Full color prints can be produced.

  Further, a strong pressing force is easily applied to the toner on the developing roller, and the toner particles are easily damaged and the external additive is easily peeled off. In the present invention, the external additive does not peel from the surface of the toner particles, and even if the toner is exposed to a strong pressing force due to the action of a spacer or the like, the toner particles are prevented from colliding with each other to break the toner. It is thought that it is preventing.

  Further, it is considered that the contamination due to toner adhesion can be prevented because the toner particles are less likely to adhere to the developing roller and the toner layer thickness regulating member due to the presence of the external additive.

  Furthermore, as described above, the present invention can also be applied to a two-component image forming method using a two-component developer composed of a carrier and a toner, which is called a so-called hybrid developing method or trickle developing method. The present invention can also be applied to an image forming method in which a toner image is formed through a development method.

  FIG. 1 shows an example of an image forming apparatus that can carry out the image forming method according to the present invention. As described above, the image forming method according to the present invention is not realized only by the image forming apparatus having the configuration shown in FIG. The image forming apparatus shown in FIG. 1 is a full-color image forming apparatus in which the developing device 20 shown in FIG. 2 can be mounted. The image forming apparatus on which the developing device 20 shown in FIG. 2 can be mounted is not limited to that shown in FIG. For example, the present invention can be applied to an image forming apparatus called a tandem type having a structure in which developing devices 20 described later are arranged in series.

  The image forming apparatus shown in FIG. 1 has a needle electrode charging type charging device 16 that uniformly charges the surface of the photosensitive drum 15 to a predetermined potential around the photosensitive drum 15 that is rotationally driven, and residual toner on the photosensitive drum 15. A cleaner 17 to be removed is provided.

  The laser scanning optical system 18 scans and exposes the photosensitive drum 15 uniformly charged by the charging device 16 to form an electrostatic latent image on the photosensitive drum 15. The laser scanning optical system 18 includes a laser diode, a polygon mirror, and an fθ optical element, and print data for each of yellow, magenta, cyan, and black is transferred from the host computer to the control unit. Based on the print data of each color, a laser beam is sequentially output, and the photosensitive drum 15 is scanned and exposed to form an electrostatic latent image for each color.

  The developing device unit 30 containing the developing device 20 supplies each color toner to the photosensitive drum 15 on which the electrostatic latent image is formed to perform development. The developing device unit 30 is provided with four developing devices 20Y, 20M, 20C, and 20Bk each containing non-magnetic one-component toners of yellow, magenta, cyan, and black around the support shaft 33. Rotating to the center, each developing device 20 is guided to a position facing the photosensitive drum 15.

  The developing device unit 30 rotates around the support shaft 33 each time an electrostatic latent image of each color is formed on the photosensitive drum 15 by the laser scanning optical system 18 and stores the corresponding color toner. 20 is guided to a position facing the photosensitive drum 15. Then, each of the developing devices 20Y, 20M, 20C, and 20Bk sequentially supplies the charged color toners onto the photosensitive drum 15 to perform development.

  In the image forming apparatus shown in FIG. 1, an endless intermediate transfer belt 40 is provided downstream of the developing device unit 30 in the rotation direction of the photosensitive drum 15, and is driven to rotate in synchronization with the photosensitive drum 15. The intermediate transfer belt 40 comes into contact with the photosensitive drum 15 at a portion pressed by the primary transfer roller 41 and transfers the toner image formed on the photosensitive drum 15. Further, a secondary transfer roller 43 is rotatably provided so as to face the support roller 42 that supports the intermediate transfer belt 40, and the portion on the intermediate transfer belt 40 is opposed to the support roller 42 and the secondary transfer roller 43. The toner image is pressed and transferred onto the recording material S such as recording paper.

  A cleaner 50 that removes residual toner on the intermediate transfer belt 40 is provided between the developing device unit 30 and the intermediate transfer belt 40 so as to be able to contact and separate from the intermediate transfer belt 40.

  A paper feeding unit 60 that guides the recording material S to the intermediate transfer belt 40 includes a paper feeding tray 61 that houses the recording material S, and a paper feeding roller 62 that feeds the recording material S stored in the paper feeding tray 61 one by one. It comprises a timing roller 63 that feeds the fed recording material S to the secondary transfer site.

  The recording material S on which the toner image is pressed and transferred is conveyed to the fixing device 70 by a conveying means 66 constituted by an air suction belt or the like, and the toner image transferred by the fixing device 70 is fixed on the recording material S. After fixing, the recording material S is transported through the vertical transport path 80 and discharged onto the upper surface of the apparatus main body 100.

  Next, as an example of a developing device that can be used in the image forming method according to the present invention, a developing device of a non-magnetic one-component developing system shown in FIG. 2 will be described. The developing device 20 is also referred to as a “toner cartridge” and has a unit form in which constituent members such as a developing roller are integrally disposed in addition to a toner storage portion that stores toner, and the device is loaded into the image forming apparatus as it is. It is designed so that toner can be supplied.

  The developing device 20 includes a developing roller 10, a buffer chamber 22 provided on the left side of the developing roller 10, and a hopper 23 adjacent to the buffer chamber 22. The hopper 23 corresponds to the toner storage portion described above. The developing roller 10 is rotationally driven in a counterclockwise direction in the drawing by a motor (not shown), and contacts or approaches an image carrier that is incorporated in an image forming apparatus (not shown).

  In the buffer chamber 22, a blade 24 as a toner layer regulating member is disposed in pressure contact with the developing roller 10. Here, the blade 24 regulates the toner layer thickness and functions as a charge imparting member that charges the toner carried on the developing roller. Further, a supply roller 26 is pressed against the developing roller 10. The supply roller 26 supplies toner to the surface of the developing roller 10 by being driven to rotate in the same direction as the developing roller 10 (counterclockwise direction in the drawing) by a motor (not shown). The supply roller 26 has a conductive cylindrical substrate and a foam layer formed of urethane foam or the like on the outer periphery of the substrate.

  The blade 24 that is a toner layer regulating member regulates the charge amount and adhesion amount of the toner on the developing roller 10. In addition, an auxiliary blade 25 that assists in regulating the charge amount and adhesion amount of toner on the developing roller 10 can be further provided on the downstream side of the blade 24 with respect to the rotation direction of the developing roller 10.

  The blade 24 that also functions as a charge imparting member forms a uniform thin layer of toner on the developing roller and triboelectrically charges the toner. The blade 24 is made of a member having a certain degree of elasticity, and forms a thin layer of toner on the developing roller by contacting the developing roller. The blade 24, which is a toner layer regulating member, uses stainless steel or phosphor bronze as it is, and those whose surfaces are coated with a urethane resin or an epoxy resin, or an inorganic compound such as silica or titanic acid compound by a sol-gel method or the like. A coated one can be used. In addition, an elastic material having a hardness specified by JIS A such as silicone rubber and urethane rubber of 40 ° to 90 ° can also be used.

  The toner thin layer formed on the developing roller has a maximum thickness of 10 toner particles, preferably 5 or less. Specifically, the peripheral speed of the electrostatic latent image carrier 11 is 100 mm / sec, the peripheral speed of the developing roller 10 is 200 mm / sec, and the pressing force of the toner regulating member 24 to the developing roller 10 is 10 to 100 N / m. In this case, a layer having a thickness of about 1.5 toner particles can be formed.

  Further, the contact force of the blade 24 to the developing roller is preferably 100 mN / cm to 5 N / cm, and particularly preferably 200 mN / cm to 4 N / cm. By setting the contact force within this range, the toner can be conveyed without causing unevenness in conveyance, so that the occurrence of image defects such as white stripes can be avoided. Further, by setting the contact force within the above range, the toner layer can be formed on the developing roller and friction charging can be performed without deforming or crushing the toner.

  In this way, in the developing device 20, the developing roller 10 and the blade 24, which is a toner layer regulating member, are disposed so as to contact each other, and a thin layer of toner is formed on the developing roller by the toner layer regulating member. Then, the toner that is thinned on the developing roller and frictionally charged is supplied onto the image carrier, whereby the electrostatic latent image formed on the image carrier can be visualized.

  A hopper 23 constituting the developing device 20 contains toner T as a one-component developer. The hopper 23 is provided with a rotating body 27 for stirring the toner T. A film-like conveying blade is attached to the rotating body 27, and the toner T is conveyed by the rotation of the rotating body 27 in the direction of the arrow. The toner T conveyed by the conveying blades is supplied to the buffer chamber 22 through a passage 28 provided in a partition wall that separates the hopper 23 and the buffer chamber 22. The shape of the conveying blade is bent while conveying the toner T in front of the rotation direction of the blade as the rotating body 27 rotates, and returns to a straight state when the left end of the passage 28 is reached. In this way, the blades supply the toner T to the passage 28 by making the shape return straight after passing through the curved state.

  The passage 28 is provided with a valve 281 for closing the passage 28. This valve is a film-like member, one end of which is fixed to the upper side of the right side of the passage 28 of the partition wall. When the toner T is supplied from the hopper 23 to the passage 28, the valve 28 is pushed rightward by the pressing force from the toner T. Is supposed to open. As a result, the toner T is supplied into the buffer chamber 22.

  In addition, a regulating member 282 is attached to the other end of the valve 281. The regulating member 282 and the supply roller 26 are arranged so as to form a slight gap even when the valve 281 closes the passage 28. The regulating member 282 adjusts so that the amount of toner accumulated at the bottom of the buffer chamber 22 does not become excessive, so that a large amount of toner T collected from the developing roller 10 to the supply roller 26 does not fall to the bottom of the buffer chamber 22. Adjusted to

  In the developing device 20, the developing roller 10 is rotationally driven in the direction of the arrow during image formation, and the toner in the buffer chamber 22 is supplied onto the developing roller 10 by the rotation of the supply roller 26. The toner T supplied onto the developing roller 10 is charged and thinned by a blade 24 and an auxiliary blade 25, and then conveyed to a region facing the image carrier to develop an electrostatic latent image on the image carrier. To be served. The toner that has not been used for development returns to the buffer chamber 22 as the developing roller 10 rotates, and is scraped and collected from the developing roller 10 by the supply roller 26.

  The developing bias power supply 29 provided in the developing device 20 forms an alternating electric field (for example, Vpp is 2.0 kV, frequency 2 kHz) with a DC voltage power source that outputs a set value (for example, about 500 V) of the developing bias voltage Vb. It consists of an AC power supply. “Vpp” indicates a peak-to-peak voltage that is the difference between the peak and valley of the amplitude of the alternating voltage waveform.

  At the time of image formation, the electrostatic latent image carrier 11 is uniformly charged to a potential of, for example, about 800 V by a charging device (not shown), and then a predetermined portion is exposed by an optical head such as a laser. An electrostatic latent image is formed by being attenuated to a potential of about 100V.

In the developing region, the toner formed in a thin layer on the developing roller 10 flies from the circumferential surface of the developing roller 10 by the action of an electric field formed by the developing bias voltage Vb applied from the developing bias power supply device 29 and an alternating voltage. To become a cloud cloud. Then, by supplying toner onto the electrostatic latent image carrier on which the electrostatic latent image is formed, the electrostatic latent image is developed and a toner image is formed.
(Description of two-component development type image forming apparatus; from B13570JP01)
The image forming method according to the present invention can also be performed using a two-component developer composed of a toner and a carrier.

  FIG. 3 is a schematic diagram illustrating an example of an image forming apparatus capable of forming a full-color image using a two-component developer.

  In FIG. 1, 15Y, 15M, 15C, and 15K are photosensitive members, 20Y, 20M, 20C, and 20K are developing devices (developing units), and 41Y, 41M, 41C, and 41K are primary transfer rolls as primary transfer units, Reference numeral 43 denotes a secondary transfer roll as a secondary transfer means, 50Y, 50M, 50C and 50K denote cleaning devices, 4 denotes an intermediate transfer body unit, 70 denotes a heat roll type fixing device, and 40 denotes an intermediate transfer body.

  This image forming apparatus is called a tandem color image forming apparatus, and includes a plurality of sets of image forming units 20Y, 20M, 20C, and 20K, an endless belt-shaped intermediate transfer body unit 4 as a transfer unit, and a recording member P. It has an endless belt-shaped paper feeding and conveying means 21 for conveyance and a heat roll type fixing device 70 as a fixing means. A document image reading device SC is disposed above the main body A of the image forming apparatus.

  An image forming unit Y that forms a yellow image as one of the different color toner images formed on each photoconductor is arranged around a drum-shaped photoconductor 15Y as the first photoconductor and the photoconductor 15Y. The charging unit 16Y, the exposure unit 18Y, the developing unit 20Y, the primary transfer roll 41Y as the primary transfer unit, and the cleaning unit 50Y are included. In addition, an image forming unit M that forms a magenta image as one of toner images of different colors is a drum-shaped photoconductor 15M as a first photoconductor, and a charge disposed around the photoconductor 15M. Means 16M, exposure means 18M, development means 20M, primary transfer roll 41M as primary transfer means, and cleaning means 50M. In addition, an image forming unit C that forms a cyan image as one of toner images of different colors is a drum-shaped photoconductor 15C as a first photoconductor, and a charge disposed around the photoconductor 15C. Means 16C, exposure means 18C, development means 20C, primary transfer roll 41C as primary transfer means, and cleaning means 50C.

  Further, an image forming portion K that forms a black image as one of other different color toner images is disposed around a drum-shaped photoconductor 15K as a first photoconductor, and the photoconductor 15K. It has a charging means 16K, an exposure means 18K, a developing means 20K, a primary transfer roll 41K as a primary transfer means, and a cleaning means 50K.

  The endless belt-shaped intermediate transfer body unit 4 has an endless belt-shaped intermediate transfer body 40 as an intermediate transfer endless belt-shaped second image carrier that is wound around a plurality of rolls and is rotatably supported.

  The respective color images formed by the image forming units Y, M, C, and K are sequentially transferred onto the rotating endless belt-shaped intermediate transfer body 40 by the primary transfer rolls 41Y, 41M, 41C, and 41K to be combined. A colored image is formed. A recording member S such as a sheet as a transfer material accommodated in the sheet feeding cassette 60 is fed by a sheet feeding / conveying means 61, passes through a plurality of intermediate rolls 62A, 62B, 62C, 62D, and a registration roll 63, and then is secondary. It is conveyed to secondary transfer rolls 43A and 43B as transfer means, and color images are transferred onto the recording member S at once. The recording member S to which the color image has been transferred is fixed by the heat roll type fixing device 70, is sandwiched between the paper discharge rolls 75, and is placed on the paper discharge tray 76 outside the apparatus.

  On the other hand, after the color image is transferred to the recording member P by the secondary transfer rolls 43A and 43B, the residual toner is removed by the cleaning unit 48 from the endless belt-shaped intermediate transfer body 40 in which the recording member S is separated by curvature.

  During the image forming process, the primary transfer roll 41K is always in pressure contact with the photoreceptor 15K. The other primary transfer rolls 41Y, 41M, and 41C are in pressure contact with the corresponding photoreceptors 15Y, 15M, and 15C, respectively, only during color image formation.

  The secondary transfer rolls 43A and 43B are in pressure contact with the endless belt-shaped intermediate transfer body 40 only when the recording member S passes through the secondary transfer rolls 43A and 43B.

  In this way, a toner image is formed on the photoreceptors 15Y, 15M, 15C, and 15K by charging, exposure, and development, and the toner images of the respective colors are superimposed on the endless belt-shaped intermediate transfer body 40, and are collectively applied to the recording member P. The image is transferred and fixed by the fixing device 70 by pressing and heating. The photoconductors 15Y, 15M, 15C, and 15K after the toner image is transferred to the recording member S are cleaned by the cleaning device 50 after the toner remaining on the photoconductor is transferred, and then the charging, exposure, and development cycle described above. The next image formation is performed.

  Hereinafter, the present invention will be described in more detail with reference to production examples and examples, but the present invention is not limited to these examples.

(Tiacalixarene: Preparation Example of Compound No. 50)
In a eggplant-shaped flask equipped with a reflux condenser, 100 g of the compound A obtained in Example 1 was dissolved in 3 L of chloroform, 5 L of acetic acid and 200 g of sodium perborate were added, and the mixture was stirred at 50 ° C. for 18 hours. After allowing to cool, the product was extracted from the resulting reaction solution with chloroform. The chloroform phase was washed with 2N hydrochloric acid, dried over anhydrous magnesium sulfate, and chloroform was distilled off to obtain a white powder. This was recrystallized from benzene-methanol to give 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrahydroxy-2,8,14,20-tetrasulfonyl [1.9. .3.1.1 ^3,7 1 ^9,13 1 ^15,19] Okutakosa -1 (25), 3,5,7 (28), 9,11,13 (27), 15,17,19 (26 ) 21,23-dodecaene (compound 50; in the general formula (1), X = SO ₂ , Y = tert-butyl, Z = H, n = 4) was obtained.

(Tiacalixarene: Preparation Example of Compound No. 40)
After washing 50 g of NaH (60 mass% mineral oil solution) with anhydrous n-hexane, 500 ml of anhydrous dimethylformamide was added and stirred. 100 g of the compound A obtained in Example 1 was dissolved in 5 L of anhydrous toluene, and this was dropped into the dispersion solution. After stirring at room temperature for 2 hours, 500 L of methyl iodide was added, and the mixture was further stirred at room temperature for 2 hours, then at 60 ° C. for 30 minutes, at 80 ° C. for 1 hour, and heated to reflux at 120 ° C. for 2 hours. After standing to cool, 5 L of 1N hydrochloric acid was added thereto and extracted with toluene. This solution was washed with a 10% by mass aqueous sodium thiosulfate solution and further with distilled water, and the solvent was distilled off to obtain 130 g of a reaction product. The reaction mixture was washed with methanol and then with acetone. The insoluble content of the residue was dissolved in chloroform, the insoluble content was removed by filtration, and the solvent was distilled off to obtain 113 g of white crystals. The crude product was further dissolved in chloroform, 5 L of acetone was added, and the precipitated crystals were filtered to obtain 5,11,17,23-tetra-tert-butyl-25,26,27,28- tetramethoxysilane -2,8,14,20- Tetorachia ^[1.9.3.1.1 3,7 ^{1 9,13} 1 ^15,19] Okutakosa -1 (25), 3,5,7 (28), 9, 11, 13 (27), 15, 17, 19 (26), 21,3-dodecaene (compound 40; X = S, Y = tert-butyl, Z = CH ₃ , n = 4) A charge control agent was obtained.
(1) Preparation of “external additive particles (a) to (su)” The following “small-diameter external additive particles (a) to (su)” were prepared. That is,
Small-diameter external additive particles (A); silica particles having a number average primary particle size of 7 nm Small-diameter external additive particles (A); silica particles having a number-average primary particle size of 13 nm Small-diameter external additive particles (U); Silica particles having a secondary particle size of 21 nm Small external additive particles (D); silica particles having a number average primary particle size of 40 nm The silica was hydrophobized with HMDS.

Small-diameter external additive particles (v); anatase-type titania particles having a number average primary particle size of 15 nm Small-diameter external additive particles (f); rutile-type hydrophobic titania having a number-average primary particle size of 35 nm Hydrophobization treatment was performed with butyltrimethoxysilane.

Large-diameter external additive particles (G); Number average primary particle size 55 nm hydrophobic silica Large-diameter external additive particles (K); Number-average primary particle size 80 nm hydrophobic silica Large-diameter external additive particles (K); Number average primary particle size 110 nm hydrophobic silica Large diameter external additive particles (co); Number average primary particle size 150 nm hydrophobic silica Large diameter external additive particles (sa); Number average primary particle size 250 nm hydrophobic silica As described above, the silica was hydrophobized with HMDS.

Large diameter external additive particles (f); number average primary particle size 120 nm calcium titanate Large diameter external additive particles (su); number average primary particle size 330 nm calcium titanate Above, calcium titanate is treated with silicone oil The hydrophobization treatment was performed.
(Example of production of 50 to 300 nm external additive)
(Preparation of silica particles)
In a glass reactor equipped with a stirrer, a dropping funnel, and a thermometer, 623.7 g of methanol, 41.4 g of water, and 49.8 g of 28 mass% aqueous ammonia were mixed. The resulting solution was adjusted to 35 ° C., and while stirring, 1163.7 g (7.65 mol) of tetramethoxysilane and 418.1 g of 5.4% by mass ammonia water were simultaneously added. Ammonia water was added dropwise over 6 hours over 6 hours. Even after the dropping was finished, the mixture was further stirred for 0.5 hours for hydrolysis to obtain a methanol-water dispersion of hydrophilic spherical silica particles.

  The methanol-water dispersion was subjected to hydrophobic treatment by adding 484 g (3 mol) of hexamethyldisilazane at room temperature to obtain silica particles.

(Production of silica particles (ki), (ku), (ko), (sa))
By changing the dripping conditions in the production conditions of silica particles, hydrophobic silica, ki, k, k, and sa having primary particle average particle sizes of 55, 80, 150, and 250 nm were obtained.
(Example of toner production)
Production of “Cyan toner base particles 1C, yellow toner base particles 1Y, magenta toner base particles 1M, black toner base particles 1K” by emulsion polymerization association method “Colorant particle dispersions Y, M, C, K” (1) Preparation of “Colorant Particle Dispersion C” 59 parts by mass of sodium dodecyl sulfate was added to 1600 parts by mass of ion-exchanged water and dissolved, and the solution prepared was stirred, and the solution was cyan-colored. 200 parts by mass of “CI Pigment Blue 15: 3” as an agent was gradually added. Next, the dispersion treatment apparatus “SC Mill (manufactured by Mitsui Mining Co., Ltd.)” was used for dispersion treatment to prepare cyan “colorant particle dispersion C”.

  “Cyan colorant particles C” in “Colorant particle dispersion C” had a volume-based median diameter of 150 nm. The volume-based median diameter was measured using a dynamic light scattering particle size analyzer “MICROTRAC UPA-150 (manufactured by HONEYWELL)” under the following measurement conditions.

Sample refractive index 1.59
Sample specific gravity 1.05 (in terms of spherical particles)
Solvent refractive index 1.33
Solvent viscosity 0.797 (30 ° C), 1.002 (20 ° C)
0-point adjustment Ion-exchanged water was added to the measurement cell for preparation.

(2) Preparation of “Colorant Particle Dispersion Y, M, K” In place of “CI Pigment Blue 15: 3” used in the preparation of “Colorant Particle Dispersion C”, a yellow colorant was used. A “colorant particle dispersion Y” of yellow color was prepared in the same procedure except that it was changed to 200 parts by mass of “CI Pigment Yellow 74”. Also, instead of “CI Pigment Blue 15: 3” used in the preparation of “Colorant Particle Dispersion C”, the mass was changed to 200 parts by mass of “CI Pigment Red 122” which is a magenta colorant. A magenta “colorant particle dispersion M” was prepared in the same manner as described above.

  Furthermore, the amount of sodium dodecyl sulfate added to the preparation of the “cyan colorant particle dispersion C” was changed to 90 parts by mass, and the carbon black “Regal 330R (Cabot) was replaced with“ CI Pigment Blue 15: 3 ”. The product was changed to 420 parts by mass. Other than that, “black colorant particle dispersion K” was prepared by the same procedure.

The volume-based median diameter of “yellow colorant particle Y” measured by the particle size analyzer is 152 nm, the volume-based median diameter of “magenta colorant particle M is 154 nm, and the volume-based median diameter of“ black colorant particle K ”is 132 nm. Met.
Preparation of “Charge Control Agent Dispersion” A solution prepared by adding and dissolving 59 parts by weight of sodium dodecyl sulfate to 1600 parts by weight of ion-exchanged water is allowed to stir. 52) 200 parts by weight were added. Next, dispersion treatment was performed using a dispersion treatment apparatus “SC Mill (Mitsui Mine Co., Ltd.)” to prepare a volume-based median diameter of 200 nm or less.
Preparation of “toner base particles 1C, 1Y, 1M, 1K” (1) Preparation of “cyan toner base particles 1C” “Cyan toner base particles 1C” were prepared according to the following procedure.

(A) First-stage polymerization In a reaction vessel equipped with a stirrer, temperature sensor, condenser, and nitrogen introducing device, 8 parts by mass of sodium dodecyl sulfate is added to 3000 parts by mass of ion-exchanged water, and the stirring speed is 230 rpm under a nitrogen stream. The internal temperature was raised to 80 ° C. with stirring. After raising the temperature, 10 parts by mass of potassium persulfate dissolved in 200 parts by mass of ion-exchanged water was added, the temperature of the liquid was again set to 80 ° C., and the following “monomer mixed solution 1” was added dropwise over 1 hour. did.

Styrene 480 parts by weight n-butyl acrylate 250 parts by weight Methacrylic acid 68 parts by weight n-octyl mercaptan 16 parts by weight The above “monomer mixed solution 1” was added dropwise, followed by heating and stirring at 80 ° C. for 2 hours for polymerization. And resin particles were produced. This is designated as “resin particle 1H”.

(B) Second-stage polymerization In a reaction vessel equipped with a stirrer, a temperature sensor, a cooling pipe, and a nitrogen introducing device, 7 parts by mass of polyoxyethylene dodecyl ether sulfate sodium salt is dissolved in 800 parts by mass of ion-exchanged water, and the interface. An activator solution was prepared and the surfactant solution was heated to 98 ° C.

  After heating to 98 ° C., 260 parts by mass of “Resin Particle 1H” and “Monomer Mixed Solution 2” consisting of the following compounds were added. “Monomer mixed solution 2” is a solution in which the following compound is dissolved at 90 ° C.

Styrene 245 parts by mass n-butyl acrylate 120 parts by mass n-octyl mercaptan 1.5 parts by mass Ester wax (pentaerythritol tetrabehenate; melting point 70 ° C.)
190 parts by mass After adding the “resin particles 1H” and the “monomer mixed solution 2”, a dispersion process is performed for 1 hour using a mechanical disperser “CLEAMIX (manufactured by M Technique)” having a circulation path. As a result, a dispersion containing emulsified particles was prepared.

  Next, an initiator aqueous solution in which 6 parts by mass of potassium persulfate is dissolved in 200 parts by mass of ion-exchanged water is added to the dispersion, and the system is heated to 82 ° C., followed by heating and stirring for 1 hour. Polymerization (second stage polymerization) was performed to prepare resin particles. This is designated as “resin particle 1HM”.

(C) Third-stage polymerization A polymerization initiator solution in which 11 parts by mass of potassium persulfate is dissolved in 400 parts by mass of ion-exchanged water is added to the dispersion of “resin particles 1HM” obtained by the second-stage polymerization. Then, under a temperature condition of 82 ° C., “monomer mixed solution 3” made of the following compound was added dropwise over 1 hour. That is,
Styrene 435 parts by weight n-butyl acrylate 130 parts by weight Methacrylic acid 33 parts by weight n-octyl mercaptan 8 parts by weight After completion of dropping, the mixture is heated and stirred for 2 hours to perform polymerization (third stage polymerization). Cooling to 0 ° C. produced “resin particles A1”.

(D) Production of “resin particle B1” “Resin particle B1” was prepared in the same procedure except that the monomer mixture used in the first stage polymerization in the production of “resin particle A1” was changed to the following. Was made.

Styrene 624 parts by mass 2-ethylhexyl acrylate 120 parts by mass Methacrylic acid 56 parts by mass n-octyl mercaptan 16.4 parts by mass (e) Aggregation / fusion process Reaction vessel equipped with a stirrer, temperature sensor, condenser, and nitrogen inlet A solution prepared by dissolving 3 parts by mass of sodium dodecyl ether sulfate in 120 parts by mass of ion-exchanged water was added, and the following were further added and stirred. That is,
Resin particle A1 300 mass parts (solid content conversion)
Ion-exchanged water 1400 parts by mass Colorant particle dispersion C 120 parts by mass (solid content conversion)
After the above substances were added, the temperature in the reaction vessel was adjusted to 30 ° C., and then the pH was adjusted to 10 by adding a 5 mol / liter aqueous sodium hydroxide solution.

  The reaction system was allowed to stir, and an aqueous solution in which 35 parts by mass of magnesium chloride hexahydrate was dissolved in 35 parts by mass of ion-exchanged water was added over 10 minutes at 30 ° C. with stirring. After the addition, the mixture is allowed to stand for 3 minutes, and then the temperature rise is started. The temperature of the system is raised to 90 ° C. over 60 minutes, and the association reaction of the resin particles is performed while maintaining the temperature at 90 ° C. Grew. The growth of the colored particles was confirmed by measuring the particle size of the associated particles using “Multisizer 3 (manufactured by Beckman Coulter)”. When the volume-based median system (D50) reached 5.5 μm, 45 parts by mass of the “resin particle B1” was added in terms of solid content, and particle growth was continued.

  When the colored particles reach a desired particle size, an aqueous solution in which 150 parts by mass of sodium chloride is dissolved in 600 parts by mass of ion-exchanged water is added to stop the growth of the colored particles. After a predetermined amount shown in Table 9 was added and dispersed and adhered to the surface of the toner base, the temperature of the reaction system was set to 90 ° C. as a fusing step, followed by heating and stirring to advance fusing of the colored particles. . Fusion was continued until the average circularity of the colored particles reached 0.980 as measured by “FPIA2100 (manufactured by Sysmex Corporation)”. Thereafter, the temperature of the reaction system was cooled to 30 ° C., hydrochloric acid was added to adjust the pH to 4.0, and stirring was stopped.

(F) Washing and drying step The aqueous solution containing the colored particles was subjected to solid-liquid separation with a basket-type centrifuge “MARK III Model No. 60 × 40” (manufactured by Matsumoto Kikai Co., Ltd.) to form a wet cake of colored particles. This wet cake was washed with ion exchange water at 45 ° C. until the electric conductivity of the filtrate reached 5 μS / cm in the basket type centrifuge, and then transferred to “flash jet dryer” (manufactured by Seishin Enterprise Co., Ltd.). Drying was performed until the amount reached 0.5% by mass. In this manner, “base toner particles 1C for cyan toner” were produced. “Cyan toner base particles 1C” are cyan toner base particles having a volume-based median diameter (D50) of 5.5 μm and an average circularity of 0.985.

(G) Preparation of “toner base particles 1M, 1Y, 1K” In place of “colorant particle dispersion C” used in the preparation of “cyan toner base particles 1C”, yellow “colorant particle dispersion” A “yellow toner base particle 1Y” having a volume-based median diameter (D50v) of 5.5 μm and an average circularity of 0.985 was prepared in the same manner except that “Y” was used. In addition, the same procedure was followed except that a magenta “colorant particle dispersion M” was used instead of the “colorant particle dispersion C” used in the preparation of the “cyan toner base particles 1C”. “Magenta toner base particles 1M” having a median diameter (D50v) of 5.5 μm and an average circularity of 0.985 were produced. Furthermore, a volume-based median is obtained in the same procedure except that the black “colorant particle dispersion K” is used in place of the “colorant particle dispersion C” used in the preparation of the “base toner particles 1C”. A “black toner base particle 1K” having a diameter (D50v) of 5.5 μm and an average circularity of 0.985 was produced.

(H) Preparation of [Base Particles for Toner 9C, 10C, 9Y, 10Y, 9M, 10M, 9K, 10K] The charge agents shown in Tables 2 to 9 were changed in the same manner as the base particles 1C to 1K. Mother particles 9C, 10C, 9Y, 10Y, 9M, 10M, 9K, and 10K were prepared.
2. Cyan toner base particles for cyan toner
(1) Preparation of binder resin The following compounds are put into a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, and the reaction is continued in a nitrogen atmosphere at 230 ° C until the reaction rate reaches 90%. Processed.

Bisphenol A-ethylene oxide adduct 3250 parts by mass Terephthalic acid 830 parts by mass Titanium diisopropylate bistriethanolamate (esterification catalyst)
Thereafter, the reaction temperature was lowered to 180 ° C., 252 parts by mass of adipic acid was added, the temperature was raised to 210 ° C. at a rate of 10 ° C./hour, and the reaction treatment was performed until the reaction rate reached 90%.

Furthermore, after adding 301 parts by mass of trimellitic anhydride and performing a reaction treatment at a reaction temperature of 210 ° C. for 1 hour, the reaction was carried out at 8.3 kPa until the desired softening point was reached. Produced. The “polyester resin C” had a glass transition temperature of 55 ° C. and a softening point of 94 ° C.
(2) Preparation of “Cyan toner base particles 2C to 3C, 7C to 8C, 11 to 12C” The following compounds were sufficiently mixed with a “Henschel mixer (Mitsui Miike Mining Co., Ltd.)” and then a twin screw extrusion kneader “PCM”. It was cooled after melt-kneading using the product from which the discharge part of “-30 (Ikegai Iron Works Co., Ltd.)” was removed.

Polyester resin C 100 parts by mass C.I. I. Pigment Blue 15: 3 5 parts by mass Pentaerythritol behenate 6 parts by mass Charge control agent (Compound 51) 1 part by mass The obtained kneaded product was cooled with a cooling belt and then coarsely pulverized with a feather mill. Thereafter, the pulverization is carried out with a mechanical pulverizer “KTM (manufactured by Kawasaki Heavy Industries, Ltd.)” to an average particle size of 9 to 10 μm. The pulverization and coarse powder classification were performed until the thickness became 9 μm. Then, using a rotor type classifier (Teplex type classifier type “100ATP (manufactured by Hosokawa Micron Corporation)) from the coarse powder classifier, the volume-based median diameter is 5.9 μm and the average circularity is 0.956. “Cyan toner base particles 2C” were prepared, and the volume base median diameter and the average circularity were changed as shown in Tables 8 and 9 by changing the pulverization and classification conditions in the preparation of “Cyan toner base particles 2C”. “Base particles for cyan toner” were prepared.
(3) “Yellow toner base particles 2Y, 3Y, 7Y, 8Y, 11Y, 12Y, magenta toner base particles 2M, 3M, 7M, 8M, 11M, 12M, black toner base particles 2K, 3K, 7K, 8K , 11K, 12K ”In place of the colorant“ CI Pigment Blue 15: 3 ”in the preparation of the“ base particles for cyan toner 2C-3C, 7C-8C, 11-12C ”,“ CI. “Yellow toner base particles 2Y, 3Y, 7Y, 8Y, 11Y, 12Y” were prepared in the same procedure except that CI Pigment Yellow 180 was used.

  In addition, in the production of the “base particles for cyan toner 2C to 3C, 7C to 8C, 11 to 12C”, “CI pigment red 57: 1” is used instead of the colorant “CI pigment blue 15: 3”. "Magenta toner base particles 2M, 3M, 7M, 8M, 11M, 12M" were prepared in the same procedure.

Further, carbon black “MA100S (Mitsubishi Chemical Corporation) is used instead of the colorant“ CI Pigment Blue 15: 3 ”in the preparation of the“ base particles for cyan toner 2C to 3C, 7C to 8C, 11 to 12C ”. The “black toner base particles 2K, 3K, 7K, 8K, 11K, and 12K” were prepared in the same procedure except that the “made” was used.
“Toner Production Example Toner Base Particles 4C, 4Y, 4M, 4K”
To 100 parts of the toner base particles 2C, 0.3 part by weight of hydrophobic silica (A: above) and 0.5 part by weight of hydrophobic silica (C: above) are added, and the peripheral speed is 30 m / sec using a Henschel mixer. For 90 seconds. Each of the obtained toners is surface-treated with a surface modification device (surfing system; manufactured by Nippon Pneumatic Kogyo Co., Ltd.) under the following conditions to obtain toner base particles 4C shown in Tables 8 and 9. It was. Similarly, 4Y, 4M, and 4K base particles were obtained.

Surface conditions are: maximum temperature: 250 ° C., residence time: 0.5 seconds, powder dispersion concentration: 100 g / m ³ , cooling air temperature: 18 ° C., cooling water temperature: 20 ° C.
“Toner Production Example Toner Base Particles 5C, 5Y, 5M, 5K”
Addition of 0.3 part by weight of hydrophobic silica (A: mentioned above) and 0.5 part by weight of the charge control agent (compound 51) according to the present invention to 100 parts of toner base particles 9C (base without charge control agent) Then, a mixing process was performed for 90 seconds at a peripheral speed of 30 m / sec using a Henschel mixer. The obtained particles are subjected to a surface treatment at 6000 rpm for 3 minutes using a hybridization system (NHS-3 type; manufactured by Nara Machinery Co., Ltd.) to immobilize the charge control agent on the surface of the toner base, and thereby toner base particles 5C for toner. Got. Similarly, base particles of 5Y, 5M, and 5K were obtained.
“Toner Production Example Toner Base Particles 6C, 6Y, 6M, 6K”
After adding 451 g of 0.1M-Na ₃ PO ₄ aqueous solution to 709 g of ion-exchanged water and heating to 60 ° C., the mixture was stirred at 12,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.). To this, 67.7 g of 1.0 M CaCl ₂ aqueous solution was gradually added to obtain an aqueous medium containing Ca ₃ (PO ₄ ) ₂ .

170g of styrene
2-ethylhexyl acrylate 30g
C. I. Pigment Blue 15: 3 10g
Pentaerythritol behenate 12g
The above formulation was heated to 60 ° C., and uniformly dissolved and dispersed at 12,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.). In this, 10 g of polymerization initiator, 2,2′-azobis (2,4-dimethylvaleronitrile), and 1.2 g of dimethyl 2,2′-azobisisobutyrate are dissolved to prepare a polymerizable monomer system. did. The polymerizable monomer system was put into the aqueous medium and stirred at 12,000 rpm for 20 minutes with a TK homomixer at 60 ° C. in an N 2 atmosphere to granulate the polymerizable monomer system. Then, after making it react with a paddle stirring blade for 3 hours at 60 degreeC, the liquid temperature was made into 80 degreeC and it was made to react for 10 hours.

After completion of the polymerization reaction, suspension is performed while adding 200 mmHg (mmHg represents 133 Pa) under reduced pressure, under ultrasonic irradiation (20 KHz, 30 W), an oil bath temperature of 150 ° C., and adding water so that the liquid volume of the suspension does not change. Water for 100% by mass of the turbid liquid was distilled off. Thereafter, the mixture was cooled, hydrochloric acid was added, Ca ₃ (PO ₄ ) ₂ was dissolved, filtered, washed with water, and dried to obtain toner base particles 6C.

6Y, 6M, and 6K base particles were obtained by the same method as 6C, except that the addition amount to the same pigment and resin component as toner base particles 2Y, 2M, and 2K was adjusted.
Production of “Cyan Toner 1-41, Yellow Toner 1-41, Magenta Toner 1-41, and Black Toner 1-41” For each “toner base particle” as shown in Tables 2 to 9 in the following procedure. By adding an external additive and performing the treatment, “Cyan toner 1 to 41, yellow toner 1 to 41, magenta toner 1 to 41, black toner 1 to 41” were produced.

  First, the aforementioned small-diameter external additive particles (A) to (G), which are external additives other than the large-diameter external additive, were added to the surface of the toner base particles as shown in Tables 2 to 9.

  The toner base particles and the small-sized external additive particles are weighed and put into a Henschel mixer “FM10B (Mitsui Miike Chemical Co., Ltd.)”, and the peripheral speed of the stirring blade is 40 m / sec at a temperature of 25 ° C. Processing was performed with the time set to 5 minutes. In the case of adding large-diameter external additive particles, next, large-diameter external additive particles are added as shown in Tables 2 to 9, the peripheral speed of the stirring blade is 40 m / second, and the treatment time is 20 times. After performing the treatment with the minute setting, toner particles were prepared by removing coarse particles using a sieve having an opening of 90 μm. The types and addition amounts of small-diameter external additive particles and large-diameter external plate particles added to each toner are as shown in each table. The amount of each external additive is based on 100 parts by mass of the colored particles.

"Evaluation experiment"
"Evaluation experiment 1"
Evaluation was performed by a color laser printer “magiccolor 5440DL (manufactured by Konica Minolta Business Technologies, Inc.)” which is a commercially available non-magnetic one-component developing type image forming apparatus. The developing devices for the yellow, magenta, cyan, and black toners for the image forming apparatus accommodate each toner in the combinations shown in Table 10, Table 11, and Table 12, and are mounted on the image forming apparatus. . A combination of toners satisfying the configuration of the present invention was designated as “Example 28”, and a toner not satisfying the configuration of the present invention was designated as “Comparative Examples 11 to 13”.

  Changes in image quality under a high temperature and high humidity environment (temperature 30 ° C., humidity 85% RH) and a low temperature and low humidity environment (temperature 10 ° C., humidity 15% RH) were evaluated as described below. Outputs a color image composed of yellow, magenta, cyan, red, green, blue, and black with a pixel ratio of 1% in full color mode on A4 size paper, and outputs 10,000 sheets continuously in single sheet intermittent mode. To do. Image samples for evaluation were output before and after the printing of 10,000 sheets, and the image quality after output of 10,000 sheets was compared with the initial stage.

  The image sample for evaluation is a solid color image composed of 2 cm square patches of yellow, magenta, cyan, red, green, blue, and black, a solid white image, and a 50% halftone color image having the same configuration as the solid color image. There are three types. Each of these was output one by one on A4 size paper, and the fog density, solid color image and halftone color image uniformity were evaluated, and cleaning performance and PC noise were also evaluated.

<Evaluation of fog>
The fog density in the solid white image area was measured and evaluated. Using a reflection densitometer “RD-918 (manufactured by Macbeth)”, set the reflection density of the paper used for the output of the image sample to 0, and measure the reflection density at any 10 points from the solid white image area. The arithmetic average value was defined as the fog density. A fog density of 0.003 or less was evaluated as ◯, a fog density of 0.005 or less as Δ, these were passed, and those exceeding 0.005 were rejected (x).

<Image uniformity>
The 10,000 color image patches before and after continuous output were visually observed, and the hue and uniformity (density unevenness between color images) were evaluated based on the following criteria. ○ and △ are acceptable and × is unacceptable. That is,
○: No change in hue and uniformity was observed before and after continuous output for each color image, and uniformity was observed between color images after continuous output. Δ: Some hue was observed before and after continuous output for each color image. There is a change, but there is no problem. There is no problem before and after the continuous output and the color image after the continuous output for uniformity. ×: Hue and uniformity are clearly shown before and after the continuous output for each color image. There was a change. In addition, uniformity between color images after continuous output was not recognized.
(Photoconductor and intermediate transfer body contamination assessment)
Using a color laser printer “magiccolor 5440DL (manufactured by Konica Minolta Business Technologies Co., Ltd.)” which is a non-magnetic one-component development type image forming apparatus, each in a low-temperature and low-humidity environment (temperature 10 ° C., humidity 15% RH) full color mode A color image composed of yellow, magenta, cyan, red, green, blue, and black with a pixel ratio of 1% was output on A4 size paper, and 10,000 sheets were continuously output in a single sheet intermittent mode. After the endurance, the photoreceptor and the intermediate transfer belt were visually observed and evaluated. Judgment criteria are as follows.
○: Filming and black spots (BS) were not generated on the photosensitive member and the intermediate transfer member, and there was no problem. Δ: Filming and BS were generated on either the photosensitive member or the intermediate transfer member. However, it was not visible on the copy image, and there was no problem in practical use. X: Filming and BS were generated on the photosensitive member and / or the intermediate transfer member, which could be confirmed on the image. there were.

  Table 10 shows the above results.

  As shown in Table 10, it was confirmed that "Example 28" having the constituent requirements of the present invention obtained the results satisfying the regulations for all the evaluation items, and exhibited the effects of the present invention. On the other hand, in “Comparative Examples 11 to 13” that do not satisfy the constituent requirements of the present invention, it was confirmed that the results satisfying the regulations were not obtained and the effects of the present invention were not obtained.

5-2. Evaluation experiment 2
A toner concentration of 6% is obtained by mixing each of the toners used in “Examples 1 to 27” and “Comparative Examples 1 to 10” with a ferrite carrier having a volume average particle diameter of 50 μm coated with methyl methacrylate and cyclohexyl methacrylate resin. A two-component developer was prepared. As described above, the two-component developer is added with the carrier and the toner so that the toner concentration is 6% by mass, and the rotation speed is measured using a “micro-type V-type mixer (Tsutsui Rikenki Co., Ltd.)”. It was prepared by mixing for 30 minutes at 45 rpm.

  The volume average particle diameter of the carrier is measured by a laser diffraction particle size distribution measuring apparatus “HELOS” (manufactured by SYMPATEC) equipped with a wet disperser.

  Examples and comparative examples composed of the above developers are mounted on a commercially available color composite machine “bizhub 550 (manufactured by Konica Minolta Business Technologies Co., Ltd.)” of a two-component development system, and a high temperature and high humidity environment (temperature 30). The change in image quality under low temperature and low humidity environment (temperature 10 ° C., humidity 15% RH) and the content described later were evaluated. Outputs a color image composed of yellow, magenta, cyan, red, green, blue, and black with a pixel ratio of 1% in full color mode on A4 size paper, and outputs 10,000 sheets continuously in single sheet intermittent mode. To do. Image samples for evaluation were output before and after the printing of 10,000 sheets, and the image quality after output of 10,000 sheets was compared with the initial stage.

  The image sample for evaluation is a solid color image composed of 2 cm square patches of yellow, magenta, cyan, red, green, blue, and black, a solid white image, and a 50% halftone color image having the same configuration as the solid color image. There are three types. Each of these was output one by one on A4 size paper, and the fog density, solid color image and halftone color image uniformity were evaluated, and cleaning performance and PC noise were also evaluated. Further, the same evaluation was performed under the same image forming conditions as in Evaluation Experiment No. 1. The results are shown in Tables 11 and 12.

  As shown in Tables 11 and 12, “Examples” having the constitutional requirements of the present invention obtained results satisfying the specifications of all the evaluation items, and even in the image forming method of the two-component development system, It was confirmed that the effects of the invention were expressed. On the other hand, it was confirmed that “comparative examples” that do not satisfy the constituent requirements of the present invention do not satisfy the regulations among the evaluation items, and cannot exhibit the effects of the present invention.

10 Developing roller 15 (15Y, 15M, 15C, 15K) Photosensitive drum 20 (20Y, 20M, 20C, 20K) Developing device 24 Blade (toner layer regulating member, charge imparting member)
30 Development device unit 4 Intermediate transfer body unit 40 Intermediate transfer belt 41Y, 41M, 41C, 41K Primary transfer roll 43A, 43B Secondary transfer roll 50 (50Y, 50M, 50C, 50K) Cleaner (cleaning device)
60 Paper feeder 70 Fixing device S Recording material

Claims (5)

A toner obtained by coating a toner particle containing at least a binder resin, a colorant, and a charge control agent and the surface thereof with an external additive, wherein the charge control agent is represented by the following general formula (1). A cyclic phenol sulfide selected from calixarene, sulfinylated thiacalixarene and sulfonylated thiacalixarene, wherein the external additive has inorganic particles having a number average primary particle size of 5 nm or more and less than 50, and a number average primary particle size of 50 nm. A toner comprising at least two types of inorganic particles having a particle size of 300 nm or less.

(Wherein, X represents S, SO or SO _2, Z is .n represents a hydrogen atom, an alkyl group, a substituted alkyl group, an aralkyl group, an acyl group, or an alkoxycarbonyl group is an integer of 3-9, Y is a hydrocarbon group, a halogenated hydrocarbon group, a halogen atom, —SO ₄ R ¹ or —SO ₃ R ² , R ¹ and R ² represent a hydrogen atom, a hydrocarbon group, or a metal element, Y may be the same or different.) The toner according to claim 1, wherein the inorganic particles having a number average primary particle size of 50 nm to 300 nm are spherical silica particles. 3. The toner according to claim 1, wherein the toner has a volume-based median diameter of 2.0 μm or more and 8.0 μm or less and an average circularity of 0.940 to 0.995. The toner according to claim 1, wherein the toner has a softening point temperature of 121 ° C. or lower and a glass transition temperature of 55 ° C. or lower. An image forming method for forming a toner image using at least a black toner and a color toner, wherein the toner is the toner according to claim 1.

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