JP2006039365A - Development method - Google Patents

Abstract

[PROBLEMS] To provide a developing method capable of obtaining a good image without impairing the chargeability of a toner even in long-term use.
In a developing method, a magnetic toner is conveyed to a magnetic toner carrier by a stirring / conveying member, a thin layer is formed on the magnetic toner carrier by a regulating member, and a latent image on the latent image carrier is developed.
The stirring / conveying member is
1) A sheet-like rotating body having a certain width in the longitudinal direction of the developing container,
2) The rotation center axis is disposed below the lower end of the magnetic toner carrier containing the fixed magnet,
3) The magnetic toner in the developing container is supplied to the magnetic toner carrier, and the magnetic toner magnetically restrained in the vicinity of the magnetic toner carrier is stirred.
The magnetic toner has at least a binder resin, a magnetic material, and a charge control agent,
Of the magnetic toner particles having an equivalent circle diameter of 3 μm or more obtained by a flow type particle image measuring device, particles having a coarse particle ratio of 30% or more in the particle size distribution are cumulative values based on the number of particles having a circularity of 0.920 or more. It is characterized by containing 60 mass% to 90 mass%.
[Selection figure] None

Description

  The present invention relates to a developing method in which an electrostatic image formed in a recording method such as an electrophotographic method, an electrostatic recording method, a magnetic recording method, and a toner jet recording method is developed using toner.

  A number of methods have been known for electrophotography. In general, an electro latent image (electrostatic latent image) is formed on a photosensitive member by various means using a photoconductive substance, and then the latent image is formed. The image is developed with toner and, if necessary, the toner image is transferred to a transfer material such as paper, and then fixed by heating, pressure, heating and pressurization or solvent vapor to obtain a copy. The toner remaining without being transferred to the toner is cleaned by various methods, and the above steps are repeated.

Numerous methods are known as developing methods for visualizing an electrostatic latent image using toner.
As these developing methods, for example, a one-component developing method is preferably used because a developing machine having a simple structure has no trouble, has a long life, and is easy to maintain.

  Even in the one-component development method, the toner carrier and the electrostatic latent image carrier are arranged at a certain interval, and a thin layer of toner that does not contact the latent image carrier is formed on the toner carrier, and further the toner A jumping development system in which development is performed by applying an alternating electric field between the carrier and the latent image carrier is preferably used.

  Also in this developing system, in recent years, the tendency to miniaturize has increased, and even in this developing apparatus, members that increase the size of replenishment hoppers and the like that have been used in many high-speed copying machines so far are also available. In recent years, a form in which toner is supplied directly from a toner cartridge without being used has been widely used. In addition, as the main body is downsized, the developing device itself needs to take a wide variety of configurations in addition to the conventional configuration in which toner is replenished from the upper part and transported to the developing unit at the lower part because the development space is reduced. is there.

  Many proposals have been made in the above configuration, and many proposals have also been made in a method of stirring and conveying toner. Japanese Patent Application Laid-Open No. 2004-133830 proposes a method of feeding toner to a toner carrier so as to be scooped up by the stirring / conveying member for the purpose of reducing the load on the toner stirring / conveying member.

  For example, Patent Document 2 and Patent Document 3 propose a method of providing a stirring member for scraping off the toner in the vicinity of the toner carrier so as to improve toner circulation in the developing device and achieve charging stability. Has been.

JP-A-11-119528 Japanese Patent Laid-Open No. 11-26511 JP 2000-131930 A

  Just by improving the developer configuration as in the above conventional example, especially in the case of magnetic toner having a large specific gravity, the magnetic toner is tightened by its own weight and pressed by the stirring member in the vicinity of the magnetic toner carrier in the developing unit. It becomes a packing state, impairing the circulation property of the magnetic toner and hindering the supply of the magnetic toner to the magnetic toner carrier. This causes variation in the charge amount distribution of the magnetic toner in the developing container, and easily causes image unevenness and fogging.

  In addition, since the magnetic toner carrier and the magnetic toner are in contact with each other in a pressurized state for a long period of time, the constituent components of the magnetic toner adhere to and adhere to the magnetic toner carrier. Insufficient charging of the magnetic toner tends to cause image defects.

  In addition, introducing a stirring member in the vicinity of the sleeve to prevent the packing state not only increases the number of parts in the developing unit, but also reduces the toner filling space in the developing container, which is contrary to the trend toward miniaturization.

  An object of the present invention is to provide a developing method that solves the above-described problems, is excellent in developability and durability, and achieves downsizing.

  That is, an object of the present invention is to provide a developing method capable of obtaining a good image without impairing the chargeability of the toner even in long-term use.

In order to achieve the above goal, the invention according to the present application
(1) In a developing method in which magnetic toner is conveyed to a magnetic toner carrier by a stirring / conveying member, a thin layer is formed on the magnetic toner carrier by a regulating member, and a latent image on the latent image carrier is developed.
The stirring / conveying member is
1) A sheet-like rotating body having a certain width in the longitudinal direction of the developing container,
2) The rotation center axis is disposed below the lower end of the magnetic toner carrier containing the fixed magnet,
3) The magnetic toner in the developing container is supplied to the magnetic toner carrier, and the magnetic toner magnetically restrained in the vicinity of the magnetic toner carrier is stirred.
The magnetic toner has at least a binder resin, a magnetic material, and a charge control agent,
Of the magnetic toner particles having an equivalent circle diameter of 3 μm or more obtained by a flow type particle image measuring device, particles having a coarse particle ratio of 30% or more in the particle size distribution are cumulative values based on the number of particles having a circularity of 0.920 or more. It is characterized by containing 60 mass% to 90 mass%.

Furthermore, in order to achieve the above invention, the second invention according to the present application is:
(2) An average circularity A of particles having an equivalent circle diameter of 3 μm or more obtained by a flow type particle image measuring apparatus and particles having a coarse particle ratio of 30% or more in a particle size distribution of particles having an equivalent circle diameter of 3 μm or more. The average circularity B of
0.975 <b / a <1.010
It is characterized by being described in (1).

Furthermore, in order to achieve the above invention, the third invention according to the present application is:
(3) La (mm) is the shortest distance from the rotation center of the stirring / conveying member of the developing container to the surface of the magnetic toner carrier, and the length from the rotation center of the stirring / conveying member to the end of the plate-like member is When Lb (mm)
0.1 <La-Lb <8.0
And is described in (1) or (2).

Furthermore, in order to achieve the above invention, the fourth invention according to the present application is:
(4) The agitation / conveying member and the magnetic toner carrier rotate in opposite directions, and the rotational speed R1 (rpm) of the conveying member and the rotational speed R2 (rpm) of the magnetic toner carrier are 2 × R1 <R2. <12 x R1
And is described in any one of (1) to (3).

Furthermore, in order to achieve the above-described invention, a fifth invention according to the present application provides:
(5) A resin obtained by polymerizing a monomer having at least a sulfonic acid group,
1) having a first acid value A and a second acid value B, measured by potentiometric titration,
2) The first acid value A is 2 (mgKOH / g) to 10 (mgKOH / g),
3) The first acid value A and the second acid value B are 1.20 ≦ B / A ≦ 2.00.
And is described in any one of (1) to (4).

  According to the present invention, the magnetic toner is pumped up to the magnetic toner carrier positioned above by the sheet-like stirring / conveying member having a certain width in the longitudinal direction, and the magnetic toner existing in the vicinity of the magnetic toner carrier. By defining the circularity of the coarse particles of the magnetic toner in a developing device having a scraping configuration of the toner, the charging property of the magnetic toner can be stabilized and a high-quality image can be obtained over a long period of time. Further, by using the special charge control agent of the present application, more uniform charge and stabilization can be achieved.

A feature of the present invention is a developing method in which magnetic toner is conveyed to a magnetic toner carrier by a stirring / conveying member, a thin layer is formed on the magnetic toner carrier by a regulating member, and a latent image on the latent image carrier is developed. In
The stirring / conveying member is
1) A sheet-like rotating body having a certain width in the longitudinal direction of the developing container,
2) The rotation center axis is disposed below the lower end of the magnetic toner carrier containing the fixed magnet,
3) The magnetic toner in the developing container is supplied to the magnetic toner carrier, and the magnetic toner magnetically restrained in the vicinity of the magnetic toner carrier is stirred.
The magnetic toner has at least a binder resin, a magnetic material, and a charge control agent,
Of the magnetic toner particles having an equivalent circle diameter of 3 μm or more obtained by a flow type particle image measuring device, particles having a coarse particle ratio of 30% or more in the particle size distribution are cumulative values based on the number of particles having a circularity of 0.920 or more. 60 mass% to 90 mass%.

  As described above, by making the stirring / conveying member a sheet-like rotating body having a constant width in the longitudinal direction, it becomes possible to convey the magnetic toner in the direction of the magnetic toner carrier and in the longitudinal direction. By adopting a configuration in which the toner in the vicinity of the toner carrying member is scraped off by the agitating / conveying member, the configuration can be simplified, and the size can be reduced without reducing the number of parts and losing the extra toner filling space.

  Further, one of the features of the present invention is that the rotation center of the stirring / conveying member is disposed below the lower end of the magnetic toner carrier, so that the magnetic toner in the vicinity of the magnetic toner carrier is contained. It is captured only by the magnetic restraining force of the fixed magnet and is not easily subjected to the weight of the toner or the pressure by the stirring / conveying member. For this reason, it is difficult for the toner to deteriorate due to packing phenomenon caused by excessive pressure on the magnetic toner or friction between the toners or the members in the container. Further, the magnetic toner carrier is supported by the stirring / conveying member. It is possible to achieve a reduction in driving torque when scraping the nearby magnetic toner.

  Furthermore, one of the features of the present invention is to control the shape of coarse particles in the magnetic toner. Specifically, particles having a coarse particle ratio of 30% or more in a particle size distribution in particles having an equivalent circle diameter of 3 μm or more obtained by a flow type particle image measuring device are particles having a circularity of 0.920 or more and 60% by mass to 90%. It is contained by mass% (preferably 65 mass% to 85 mass%, more preferably 70 mass% to 80 mass%). Thereby, even in the development system simplified as described above, the magnetic toner in the developing device can be uniformly charged. Usually, in the triboelectric charging system, the fine particles in the magnetic toner have a large specific surface area and are easily charged quickly compared to the coarse particles. For this reason, variation in charge occurs between the fine particles and the coarse particles, but as in the present invention, by controlling the shape of the coarse particles, the charge amount of the coarse particles is made uniform and the fluidity of the coarse particles is increased. It can be circulated in the developing unit to increase the number of times of contact / separation with the toner itself or the toner carrying member, thereby causing charge relaxation between the toners to achieve a quasi-uniformly charged state.

  When the content of particles having a circularity of 0.920 or more in a particle size distribution of an equivalent circle diameter of 30% or more obtained by a flow type particle image measuring apparatus of a magnetic toner is less than 60% by mass, the coarse particles Becomes a non-uniform particle shape and cannot be stably charged, thereby causing image unevenness, fogging and the like.

  In addition, when the content of particles having a circularity of 0.920 or more exceeds 90% by mass, the magnetic toner is easily packed in the developing unit, and similarly, it is difficult to uniformly charge the magnetic toner. Toner adherence and sticking easily occur. In particular, this phenomenon is remarkable in a developing system having a simplified stirring configuration as in the present invention.

In the present invention, the magnetic toner has an average circularity a in particles having an equivalent circle diameter of 3 μm or more obtained by a flow type particle image measuring apparatus, and a coarse particle ratio of 30% or more in a particle size distribution in particles having an equivalent circle diameter of 3 μm or more. The average circularity b of the particles of
0.975 <b / a <1.01
Is preferable in order to achieve high degree of uniform charging of the magnetic toner.

  When b / a is in the above range, coarse particles and fine particles have the same shape, and the flow of toner particles in the developing device is made uniform, and the frictional charging opportunities are made uniform. The charge of the toner in the developing device can be made highly uniform.

In the present invention, the magnetic toner preferably has a charge control agent that satisfies the following conditions.
1) having a first acid value A and a second acid value B, measured by potentiometric titration,
2) The first acid value A is 2 (mgKOH / g) to 10 (mgKOH / g),
3) The first acid value A and the second acid value B satisfy the following formula (1).
1.20 ≦ B / A ≦ 2.00 (1)

  As a result, the uniform dispersibility of the charge control agent in the toner is made higher, environmental stability and high developability can be achieved, and the toner adheres to the magnetic toner carrier in a harsh environment. The contamination phenomenon can be suppressed at a high level.

  Although a specific method for producing the charge control agent of the present invention will be described later, the first acid value A contributes to rapid charging of the toner, and the second acid value B is dispersion of the charge control agent in the toner. Contribute to.

  If the first acid value A is in the range of 2 to 10 (mgKOH / g), the copolymerization with the dispersion aid component in the toner, the charge imparting property after toner formation and the environmental stability Excellent. When the acid value is less than 2 (mgKOH / g), it may be inferior in terms of quick charge imparting property, which is not preferable. When it is 10 (mgKOH / g), the charge becomes excessive, and the toner charge state under high temperature and high humidity, low temperature and low humidity may be different, which is not preferable.

  If the second acid value B is in the range of 1.20 ≦ B / A ≦ 2.00, copolymerization with the charge imparting component in the toner is sufficient, and dispersibility in the toner is improved. Excellent and preferred. When the acid value A / B is less than 1.20 and more than 2.00, it may not be possible to uniformly disperse in the toner, which is not preferable.

  Furthermore, the weight average molecular weight (Mw) of the charge control agent of the present invention is preferably 10,000 to 100,000, more preferably 20,000 to 75,000. When Mw is less than 10,000 or more than 100,000, the dispersion in the toner may deteriorate, which is not preferable.

  Further, the weight average molecular weight W (Mw) and the number average molecular weight N (Mn) of the charge control agent of the present invention are preferably 1.2 ≦ W / N ≦ 3.5, more preferably 1.5 ≦ W. /N≦3.0. By controlling the above, the copolymerization state of the charge imparting component and the dispersion aid in the toner becomes good. When W / N exceeds 3.5, the molecular weight distribution of the charge control agent has a wide spread, which is not preferable because dispersion in the toner may deteriorate.

  Furthermore, the charge control agent of the present invention can be contained in an amount of 0.01 to 15 parts by mass per 100 parts by mass of the binder resin. Preferably 0.1-10 mass parts, More preferably, 0.5-8 mass parts is good. When the content is less than 0.01 parts by mass, the charge imparting property may be inferior, which is not preferable. On the other hand, when the amount exceeds 15 parts by mass, there is a problem with the uniform dispersibility, the charging speed is likely to vary, and image unevenness, fogging, and the like may occur.

  Furthermore, the preferable manufacturing method for obtaining the charge control agent described above will be described.

  Monomers used in the method for producing a charge control agent of the present invention are sulfo group-containing monomers, styrene monomers, and unsaturated monocarboxylic acid derivative monomers composed only of carbon, hydrogen, and oxygen.

  Examples of the sulfo group-containing monomer include sulfonic acid group-containing monomers and sulfonate group-containing monomers.

  Examples of the sulfonic acid group-containing monomer include (meth) allyl sulfonic acid, 2- (meth) acrylamido-2-methylpropane sulfonic acid, and styrene sulfonic acid.

  Examples of sulfonate group-containing monomers include alkali metal (lithium, sodium and potassium) salts, alkaline earth metal (magnesium, calcium and barium) salts, amines (triethylamine, tributylamine and dimethylbenzyl) of sulfonic acid group-containing monomers. Amine) and quaternary ammonium salts (tributylbenzylammonium salt, tetraethylammonium salt, tetrabutylammonium salt, etc.).

  Among these sulfo group-containing monomers, preferred are (meth) allylsulfonic acid, sodium (meth) allylsulfonate, 2- (meth) acrylamide-2-methylpropanesulfonic acid, 2- (meth) acrylamide-2-methyl. Propanesulfonic acid ammonium salt, 2- (meth) acrylamido-2-methylpropanesulfonic acid sodium salt, 2- (meth) acrylamido-2-methylpropanesulfonic acid potassium salt, more preferably sodium (meth) allylsulfonic acid salt 2- (meth) acrylamide-2-methylpropanesulfonic acid, 2- (meth) acrylamide-2-methylpropanesulfonic acid ammonium salt.

  Examples of styrenic monomers include styrene and hydrocarbbis (alkyl, cycloalkyl, aralkyl and / or alkenyl) substituted styrene such as α-methylstyrene, vinyltoluene, 2,4-dimethylstyrene, ethylstyrene, isopropylstyrene and butyl. Examples include styrene, crotylbenzene, divinylbenzene, divinyltoluene, divinylxylene and trivinylbenzene, and vinylnaphthalene. Of these, preferred are styrene, α-methylstyrene, and divinylbenzene, and more preferred are styrene and α-methylstyrene.

  Examples of the unsaturated monocarboxylic acid derivative monomer consisting only of carbon, hydrogen and oxygen include unsaturated monocarboxylic acids having 3 to 20 carbon atoms such as (meth) acrylic acid, crotonic acid and cinnamic acid; Unsaturated alkyl carboxylic acid esters (1 to 24 carbon atoms) such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (Meth) acrylate, stearyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, eicosyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, phenyl (meth) acrylate, and ethyl- α- Butoxy (meth) acrylate, glycidyl (meth) acrylate; hydroxyalkyl (meth) acrylates having a carbon number of 5-16, for example, hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate.

  Among these, preferred from the viewpoints of copolymerizability and the glass transition point of the copolymer are (meth) acrylic acid, alkyl (carbon number 1 to 18) ester of (meth) acrylic acid, and hydroxy group having 5 to 16 carbon atoms. Alkyl (meth) acrylates, particularly preferred are acrylic acid, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, and hydroxyethyl (meth) acrylate.

  In addition, other radical copolymerizable monomers can be copolymerized within a range that does not impair the function of the charge control agent of the present invention. Other radical copolymerizable monomers include alkenols having 2 to 12 carbon atoms, such as (meth) allyl alcohol, 1-buten-3-ol and 2-buten-1-ol; unsaturated having 4 to 30 carbon atoms Dicarboxylic acids and ester derivatives thereof [mono- or dialkyl (alkyl having 1 to 18 carbon atoms) esters] such as maleic acid, fumaric acid, itaconic acid, citraconic acid, and mono- or dialkyl thereof (alkyl having 1 to 18 carbon atoms) ) Esters (methyl esters and ethyl esters, etc.), etc .; C 4-12 alkene diols, such as 2-butene-1,4-diol; C 3-30 alkenyl ethers, such as 2-hydroxyethylpropenyl ether An alkene having 2 to 20 carbon atoms, such as ethylene, propylene, butene, iso Tylene, pentene, heptene, diisobutylene, octene, dodecene, octadecene and other α-olefins, etc .; alkadienes having 4 to 20 carbon atoms such as butadiene, isoprene, 1,4-pentadiene, 1,5-hexadiene and the like 1,7-octadiene; mono-, dicycloalkenes and alkadienes such as cyclohexene, (di) cyclopentadiene, vinylcyclohexene and ethylidenebicycloheptene; tempels such as pinene, limonene and indene; (meth) acrylonitrile and the like; amino Ethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate, N-aminoethyl (meth) acrylamide, (meth T) Allylamine, morpholinoethyl (meth) acrylate, 4-vinylpyridine, 2-vinylpyridine, crotylamine, methyl α-acetaminoacrylate, vinylimidazole, N-vinylpyrrole, N-vinylthiopyrrolidone, etc .; 3-30 carbon atoms Unsaturated carboxylic acid polyhydric (2-3) alcohol esters such as ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate 1,6-hexanediol diacrylate and polyethylene glycol di (meth) acrylate, etc .; esters of unsaturated alcohols [vinyl, isopropenyl, etc.] with mono- or polycarboxylic acids having 1 to 12 carbon atoms, for example , Vinyl acetate, vinyl butyrate, vinyl propionate, vinyl butyrate, diallyl phthalate, diallyl adipate, isopropenyl acetate, methyl 4-vinyl benzoate, and vinyl methoxyacetate and vinyl benzoate.

  As the monomer composition of the present charge control agent, the amount of the sulfo group-containing monomer is preferably 1 to 24%, preferably 2 to 15%, based on the mass, from the viewpoint of chargeability and dispersibility. More preferably, by setting the content to 3 to 10%, the polymerizability with other monomers and the charge imparting property when formed into a toner can be obtained.

  The amount of the styrenic monomer and the unsaturated monocarboxylic acid derivative monomer consisting only of carbon, hydrogen, and oxygen is preferably 50 to 98% and 1 to 49%, preferably 55 to 96% and 2 to 43%, More preferably, it is 65 to 90% and 3 to 32%. The mixing ratio of the monomers is adjusted by designing the amount of the sulfo group-containing monomer and the glass transition point of the copolymer.

  The glass transition point of the copolymer is preferably 30 to 120 ° C, preferably 50 to 100 ° C, more preferably 70 to 95 ° C. When the glass transition point is less than 30 ° C., the fluidity and storage stability of the toner may decrease, which is not preferable. When the glass transition point exceeds 120 ° C., the fixability may be deteriorated in the case of an image having a high toner printing ratio, which is not preferable.

  In the method for producing a charge control agent of the present invention, the monomers can be batch-polymerized or drop-polymerized using a radical polymerization initiator.

  The polymerization temperature is preferably 30 to 140 ° C, more preferably 50 to 120 ° C. At this time, polymerization may be performed at a constant temperature, or polymerization may be performed while changing the temperature stepwise or continuously.

  The polymerization time is preferably 1 to 30 hours, more preferably 2 to 20 hours. By setting the polymerization temperature and time to 30 to 140 ° C. and 1 to 30 hours, respectively, thermal degradation of the sulfo group-containing monomer can be prevented.

  The pressure may be selected from normal pressure, pressurized pressure, and reduced pressure depending on the form of the reaction tank and the productivity of the target resin, and the target resin is obtained through these two or more pressure states. May be.

  Examples of the polymerization initiator include azo polymerization initiators such as azobisisobutyronitrile, azobis (2,4-dimethylvaleronitrile), azobis (4-methoxy-2,4dimethylvaleronitrile), azobis (2- Methylbutyronitrile), azobis (cyclohexane-1-carbonitrile) and azobiscyanovaleric acid; organic peroxide-based polymerization initiators such as isobutyryl peroxide, octanoyl peroxide, lauroyl peroxide, tert-butylperoxy 2-ethylhexanoate, benzoyl peroxide, tert-butylperoxyisobutyrate, 1,1-bis (tert-peroxy) 3,3,5-trimethylcyclohexane, tert-butylperoxyisopropyl monocarbonate, tert- Butyl Over oxy benzoin benzoate, dicumyl peroxide, di -tert- butyl peroxide and tert- butyl hydroperoxide, and the like.

  Among these, preferred are azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile), which are water-insoluble with a solubility in water at 20 ° C. of 5% by mass or less from the viewpoint of copolymerization. , Azobis (4-methoxy-2,4dimethylvaleronitrile), azobis (2-methylbutyronitrile), azobis (cyclohexane-1-carbonitrile), octanoyl peroxide, lauroyl peroxide, benzoyl peroxide, tert- Butyl peroxyisobutyrate, 1,1-bis (tert-peroxy) 3,3,5-trimethylcyclohexane, tert-butyl peroxybenzoate.

  The amount of the polymerization initiator used is 0.1 to 10%, preferably 0.2 to 8%, more preferably 0.3 to 6% based on the total amount of monomers.

  As the polymerization solvent, a mixed system of water and an organic solvent is used. By using a solvent as a mixed system, it is possible to efficiently copolymerize a water-soluble sulfo group-containing monomer, an oil-soluble styrene monomer, and an unsaturated monocarboxylic acid derivative monomer composed only of carbon, hydrogen, and oxygen.

  Examples of the organic solvent mixed with water include hydrocarbons having 5 to 20 carbon atoms, such as pentane, hexane, heptane, octane, decane, dodecane, cyclohexane, benzene, toluene, xylene, etc .; alcohols having 1 to 12 carbon atoms, such as , Methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, isobutanol, tert-butanol, isoamyl alcohol, hexanol, 2-ethylhexanol, cyclohexanol, benzyl alcohol, ethylene glycol, propylene glycol, 1, 3-propanediol, glycerin, etc .; C2-C18 ethers such as dimethyl ether, diethyl ether, dibenzyl ether, tetrahydrofuran, dioxane, methyl cellosolve, ethyl acetate Sorb, butyl cell sorb, etc .; ketones having 3 to 18 carbon atoms such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc .; esters having 3 to 18 carbon atoms such as methyl formate, ethyl formate, methyl acetate, ethyl acetate, N-propyl acetate, isopropyl acetate, butyl acetate, methyl benzoate, ethyl benzoate, etc .; nitrogen-containing compounds having 1 to 18 carbon atoms, such as dimethylamine, trimethylamine, triethylamine, dimethylaminoethanol, dimethylformamide, dimethylacetamide, aniline , Pyridine, N-methylpyrrolidone and the like; halogen-containing compounds having 1 to 8 carbon atoms such as dichloromethane, chloroform, carbon tetrachloride, dichloroethane, 1,1,1-trichloroethane and the like. These are used alone or in combination of two or more.

  Among these, from the viewpoints of boiling point or affinity with water and economy, hexane, heptane, cyclohexane, toluene, xylene, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, Cyclohexanol, ethylene glycol, propylene glycol, diethyl ether, tetrahydrofuran, dioxane, methyl cellosolve, ethyl cellosolve, butyl cellosolve, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl formate, ethyl formate, methyl acetate, ethyl acetate, Preference is given to butyl acetate, triethylamine, dimethylformamide, dimethylacetamide, pyridine alone or in combination of two or more.

  More preferably, toluene, xylene, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, propylene glycol, tetrahydrofuran, dioxane, methyl cellosolve, ethyl cellosolve, butyl cellosolve, acetone, Methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, dimethylformamide, and dimethylacetamide are used alone or in combination of two or more.

  Furthermore, by combining two or more solvents having greatly different solubility in water, the copolymerizability of the sulfo group-containing monomer with the styrene monomer and the unsaturated monocarboxylic acid derivative monomer consisting only of carbon, hydrogen and oxygen Improved and preferred. Examples of particularly preferable organic solvent series include [a system in which at least methanol and toluene are mixed], [a system in which at least methanol and methyl ethyl ketone are mixed], [a system in which at least methanol and cyclohexane are mixed], and [at least ethanol and toluene. ], [System mixed with at least ethanol and methyl ethyl ketone], [System mixed with at least methanol and cyclohexane], [System mixed with at least isopropanol and toluene], [System mixed with at least isopropanol and methyl ethyl ketone] [Systems mixed with at least isopropanol and cyclohexane], [Systems mixed with at least acetone and toluene], [Systems mixed with at least acetone and methyl ethyl ketone], [Little systems] Both include a system in which acetone and cyclohexane are mixed], [a system in which at least tetrahydrofuran and toluene are mixed], [a system in which at least tetrahydrofuran and methyl ethyl ketone are mixed], and [a system in which at least tetrahydrofuran and cyclohexane are mixed]. .

  The mass ratio of water to these organic solvents is not particularly limited, but the amount of water in the solvent is preferably 20 to 90% from the viewpoint of easily forming a semi-suspended state at the time of polymerization. More preferably, it is 50 to 80%.

  The stirring conditions during the polymerization are largely influenced by the components of the polymerization system, and can be set arbitrarily as long as they are in a semi-suspended state, but the balance of particle size and particle stability of the resulting copolymer Therefore, it is preferable to polymerize at a shear rate of 5 to 40 (1 / sec). More preferably, it is 8-25 (1 / sec).

  The method for producing a charge control agent of the present invention is a mixture of a monomer before polymerization, a polymerization initiator and a solvent, which is dispersed when subjected to shearing such as stirring, and at least two phases when left standing without shearing. Polymerization is carried out in a semi-suspended state in which the phases are separated. By carrying out the polymerization in a semi-suspended state, the copolymer after polymerization is dispersed and precipitated in the solvent, so that separation from the solvent becomes easy. The polymerization is carried out at 20 ° C. under conditions where the suspension formed by stirring for 5 minutes at a shear rate of 10 (1 / sec) is separated into at least two phases within 20 seconds to 60 minutes without stirring. Good. Preferably, it is 30 seconds or more and 30 minutes or less, more preferably 1 minute or more and 20 minutes or less. By setting this condition, a copolymer having an appropriate dispersion diameter can be easily obtained.

  Here, the semi-suspended state in the case of performing dropping polymerization may be determined in a state in which all of the dropping liquid and the raw materials charged into the reaction tank are combined.

  By using the above-described production method, the polymerization solvent may be removed by performing a pretreatment such as salting out in some cases and then performing solid-liquid separation by a known method. Known solid-liquid separation methods include a method using a filter press, a screw decanter, a centrifuge, spray drying, vacuum drying, and the like. Alternatively, the solvent may be distilled out of the system by heating as a suitable reduced pressure after polymerization to obtain the desired resin in a molten state.

  Since the resin of the present invention does not contain a dispersant during polymerization, it is not necessary to remove these after polymerization. In many cases, the dispersant is water-soluble or semi-water-soluble, and an impurity of the charge control agent is a factor that deteriorates the environmental dependency of the toner. For this reason, when a dispersing agent is used, the process of removing these is essential, and the manufacturing process itself is complicated and prolonged. Further, even if the process described on the left is introduced, if the charge control agent is finely divided for the purpose of good dispersion in the toner, it is difficult to completely remove the charge control agent, resulting in inferior environmental stability.

  In the toner of the present invention, other charge control agents can be used as necessary in order to further stabilize the chargeability. The charge control agent is preferably used in an amount of 0.5 to 10 parts by mass per 100 parts by mass of the binder resin. When the amount is less than 0.5 parts by mass, sufficient charging characteristics may not be obtained, which is not preferable. When the amount exceeds 10 parts by mass, compatibility with other materials is deteriorated or charging is performed under low humidity. It may be excessive, which is not preferable.

  Examples of other charge control agents include the following.

  As a negative charge control agent for controlling the toner to be negative charge, for example, an organometallic complex or a chelate compound is effective. Examples include monoazo metal complexes, aromatic hydroxycarboxylic acid metal complexes, and aromatic dicarboxylic acid metal complexes. Other examples include aromatic hydroxycarboxylic acids, aromatic mono and polycarboxylic acids and metal salts thereof, anhydrides or esters thereof, or phenol derivatives of bisphenol.

  The binder resin for toner used in the present invention is preferably a polyester resin, a vinyl resin, an epoxy resin, and a binder resin containing a hybrid resin component having a vinyl polymer unit and a polyester unit.

  When a polyester resin is used as the binder resin, alcohol and carboxylic acid, carboxylic acid anhydride, carboxylic acid ester, or the like can be used as a raw material monomer. Specifically, for example, as the dihydric alcohol component, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) -2,2-bis ( 4-hydroxyphenyl) propane, polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene (2.0) -2,2 -Alkylene oxide adducts of bisphenol A such as bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, ethylene glycol, diethylene glycol, triethylene glycol, 1, 2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, Opentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A And hydrogenated bisphenol A.

  Examples of the trivalent or higher alcohol component include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, etc. Can be mentioned.

  Examples of the carboxylic acid component include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, and terephthalic acid, or anhydrides thereof; alkyl dicarboxylic acids such as succinic acid, dodecenyl succinic acid, adipic acid, sebacic acid, and azelaic acid, or anhydrides thereof; And succinic acid substituted with an alkyl group having 6 to 12 carbon atoms or an anhydride thereof; unsaturated dicarboxylic acids such as fumaric acid, maleic acid, and citraconic acid, or anhydrides thereof.

  Examples of the trivalent or higher polyvalent carboxylic acid component for forming a polyester resin having a crosslinking site include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2 1,4-naphthalenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4,5-benzenetetracarboxylic acid, and anhydrides and ester compounds thereof. The amount of the trivalent or higher polyvalent carboxylic acid component is preferably 0.1 to 1.9 mol% based on the total monomer.

  Among these, in particular, a bisphenol derivative represented by the following general formula (1) is used as a diol component, and a carboxylic acid component (for example, fumaric acid) composed of a divalent or higher carboxylic acid or an acid anhydride thereof or a lower alkyl ester thereof. A polyester resin obtained by polycondensation using acid, maleic acid, maleic anhydride, phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, etc.) as an acid component is preferable because it has good charging characteristics.

  Moreover, when using a vinyl-type copolymer resin for resin of this invention, the following are mentioned as a vinyl-type monomer for producing | generating a vinyl-type resin. Styrene; o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert- Butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p-chloro styrene, 3, Styrene and derivatives thereof such as 4-dichlorostyrene, m-nitrostyrene, o-nitrostyrene, p-nitrostyrene; styrene unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; unsaturated such as butadiene and isoprene Polyenes; vinyl chloride, vinyl chloride, vinyl bromide, fluoride Vinyl halides such as vinyl; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-methacrylate Α-methylene aliphatic monocarboxylic acid esters such as octyl, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate; methyl acrylate, ethyl acrylate Propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-acrylate Acrylic esters such as lorethyl and phenyl acrylate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and methyl isopropenyl ketone; N-vinyl pyrrole; N-vinyl compounds such as N-vinyl carbazole, N-vinyl indole and N-vinyl pyrrolidone; vinyl naphthalenes; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile and acrylamide.

  In addition, unsaturated dibasic acids such as maleic acid, citraconic acid, itaconic acid, alkenyl succinic acid, fumaric acid, mesaconic acid; maleic anhydride, citraconic anhydride, itaconic anhydride, alkenyl succinic anhydride, etc. Unsaturated dibasic acid anhydride; maleic acid methyl half ester, maleic acid ethyl half ester, maleic acid butyl half ester, citraconic acid methyl half ester, citraconic acid ethyl half ester, citraconic acid butyl half ester, itaconic acid methyl half ester, Alkenyl succinic acid half ester, fumaric acid methyl half ester, mesaconic acid methyl half ester unsaturated dibasic acid half ester; dimethylmaleic acid, dimethyl fumaric acid unsaturated dibasic acid ester; acrylic acid, meta Α, β-unsaturated acids such as rillic acid, crotonic acid and cinnamic acid; α, β-unsaturated acid anhydrides such as crotonic acid anhydride and cinnamic acid anhydride, the α, β-unsaturated acid and lower fatty acids And monomers having a carboxyl group such as alkenylmalonic acid, alkenylglutaric acid, alkenyladipic acid, acid anhydrides and monoesters thereof.

  Further, acrylic acid or methacrylic acid esters such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate; 4- (1-hydroxy-1-methylbutyl) styrene, 4- (1-hydroxy-1) -Methylhexyl) Monomers having a hydroxy group such as styrene.

  The vinyl copolymer resin that can be used in the toner of the present invention may have a crosslinked structure crosslinked with a crosslinking agent having two or more vinyl groups. In this case, the crosslinking agent used is: Examples of aromatic divinyl compounds include divinylbenzene and divinylnaphthalene; examples of diacrylate compounds linked by an alkyl chain include ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, and 1,4-butanediol di Examples include acrylate, 1,5-pentanediol diacrylate, 1,6 hexanediol diacrylate, neopentyl glycol diacrylate, and the above compounds in which acrylate is replaced by methacrylate; linked by an alkyl chain containing an ether bond. As diacrylate compounds, For example, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol # 400 diacrylate, polyethylene glycol # 600 diacrylate, dipropylene glycol diacrylate, and acrylates of the above compounds are replaced with methacrylate. Examples of diacrylate compounds linked by a chain containing an aromatic group and an ether bond include polyoxyethylene (2) -2,2-bis (4-hydroxyphenyl) propane diacrylate, polyoxyethylene (4 ) -2,2-bis (4-hydroxyphenyl) propane diacrylate and those obtained by replacing the acrylate of the above compound with methacrylate.

  Polyfunctional cross-linking agents include pentaerythritol triacrylate, trimethylol ethane triacrylate, trimethylol propane triacrylate, tetramethylol methane tetraacrylate, oligoester acrylate, and acrylates of the above compounds replaced with methacrylate; triallylcia Examples include nurate and triallyl trimellitate.

  Examples of the polymerization initiator used for producing the vinyl polymer of the present invention include 2,2′-azobisisobutyronitrile, 2,2′-azobis (4-methoxy-2,4-dimethylvalero). Nitrile), 2,2′-azobis (-2,4-dimethylvaleronitrile), 2,2′-azobis (-2methylbutyronitrile), dimethyl-2,2′-azobisisobutyrate, 1, 1′-azobis (1-cyclohexanecarbonitrile), 2- (carbamoylazo) -isobutyronitrile, 2,2′-azobis (2,4,4-trimethylpentane), 2-phenylazo-2,4-dimethyl- 4-methoxyvaleronitrile, 2,2′-azobis (2-methyl-propane), methyl ethyl ketone peroxide, acetylacetone peroxide, cyclohexane Ketone peroxides such as Sanone peroxide, 2,2-bis (t-butylperoxy) butane, t-butyl hydroperoxide, cumene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroper Oxide, di-t-butyl peroxide, t-butylcumyl peroxide, di-cumyl peroxide, α, α'-bis (t-butylperoxyisopropyl) benzene, isobutyl peroxide, octanoyl peroxide, decanoyl Peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, m-trioyl peroxide, di-isopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, -N-propyl peroxydicarbonate, di-2-ethoxyethyl peroxycarbonate, di-methoxyisopropyl peroxydicarbonate, di (3-methyl-3-methoxybutyl) peroxycarbonate, acetylcyclohexylsulfonyl peroxide, t -Butyl peroxyacetate, t-butyl peroxyisobutyrate, t-butyl peroxyneodecanoate, t-butyl peroxy 2-ethylhexanoate, t-butyl peroxylaurate, t-butyl peroxy Benzoate, t-butyl peroxyisopropyl carbonate, di-t-butyl peroxyisophthalate, t-butyl peroxyallyl carbonate, t-amyl peroxy 2-ethylhexanoate, di-t-butyl peroxyhexa Idro terephthalate, di -t- butyl peroxy azelate and the like.

  Further, when a hybrid resin having a polyester unit and a vinyl polymer unit is used as the binder resin, further improved wax dispersibility, low-temperature fixability, and offset resistance can be expected. The “hybrid resin component” used in the present invention means a resin in which a vinyl polymer unit and a polyester unit are chemically bonded. Specifically, a polyester unit and a vinyl polymer unit obtained by polymerizing a monomer having a carboxylic acid ester group such as (meth) acrylic acid ester are formed by a transesterification reaction, preferably a vinyl polymer. Is used to form a graft copolymer (or block copolymer) having a backbone polymer and a polyester unit as a branch polymer.

  In the present invention, “polyester unit” refers to a portion derived from polyester, and “vinyl copolymer unit” refers to a portion derived from a vinyl copolymer. The polyester monomer constituting the polyester unit is the polyvalent carboxylic acid component and the polyhydric alcohol component described above, and the monomer constituting the vinyl copolymer unit is the monomer component having the vinyl group described above.

  In the present invention, when a hybrid resin is used, it is preferable that a monomer component capable of reacting with both resin components is contained in the vinyl polymer component and / or the polyester resin component. Examples of the monomer constituting the polyester resin component that can react with the vinyl polymer include unsaturated dicarboxylic acids such as phthalic acid, maleic acid, citraconic acid, and itaconic acid, or anhydrides thereof. Among the monomers constituting the vinyl polymer component, those capable of reacting with the polyester resin component include those having a carboxyl group or a hydroxy group, and acrylic acid or methacrylic acid esters.

  As a method of obtaining a reaction product of a vinyl polymer and a polyester resin, either a polymer containing a monomer component capable of reacting with each of the vinyl polymer and the polyester resin listed above is present, or either A method obtained by polymerizing both resins is preferred.

  Examples of the production method capable of preparing the hybrid resin used in the toner of the present invention include the following production methods (1) to (6).

  (1) A method in which a vinyl polymer, a polyester resin, and a hybrid resin component are blended after production. The blend is produced by dissolving and swelling in an organic solvent (for example, xylene) and then distilling off the organic solvent. The hybrid resin component is synthesized by separately producing a vinyl polymer and a polyester resin, dissolving and swelling in a small amount of an organic solvent, adding an esterification catalyst and an alcohol, and performing a transesterification reaction by heating. The ester compound used can be used.

  (2) A method of producing a polyester resin and a hybrid resin component in the presence of a vinyl polymer after the production thereof. The hybrid resin component is produced by a reaction between a vinyl polymer unit (a vinyl monomer can be added if necessary) and a polyester monomer (alcohol, carboxylic acid) and / or polyester unit. Also in this case, an organic solvent can be appropriately used.

  (3) A method for producing a vinyl polymer unit and a hybrid resin component in the presence of a polyester resin after the production. The hybrid resin component is produced by a reaction between a polyester unit (a polyester monomer can be added if necessary) and a vinyl monomer and / or vinyl polymer unit.

  (4) After the vinyl polymer resin and the polyester resin are produced, a hybrid resin component is produced by adding a vinyl monomer and / or a polyester monomer (alcohol, carboxylic acid) in the presence of these polymer units. Also in this case, an organic solvent can be appropriately used.

  (5) After producing the hybrid resin component, vinyl polymer units and / or polyester units (alcohol, carboxylic acid) are added to carry out addition polymerization and / or polycondensation reaction to produce vinyl polymer units and polyester units. Is done. In this case, as the hybrid resin component, those produced by the production methods (2) to (4) can be used, and those produced by a known production method can be used as necessary. Furthermore, an organic solvent can be used as appropriate.

  (6) A vinyl polymer unit, a polyester unit, and a hybrid resin component are produced by mixing a vinyl monomer and a polyester monomer (alcohol, carboxylic acid, etc.) and continuously performing addition polymerization and condensation polymerization reaction. Furthermore, an organic solvent can be used as appropriate.

  In the production methods (1) to (5), the vinyl polymer unit and / or the polyester unit can use a plurality of polymer units having different molecular weights and crosslinking degrees.

  The glass transition temperature of the binder resin contained in the toner of the present invention is preferably 40 to 90 ° C, more preferably 45 to 85 ° C. The acid value of the resin is preferably 1 to 40 mgKOH / g.

  Examples of the release agent used in the present invention include the following. Of these, one or more release agents are contained in the toner particles as necessary.

Aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, paraffin wax, and the like, or oxides of aliphatic hydrocarbon waxes such as oxidized polyethylene wax, or block copolymers thereof; And waxes mainly composed of fatty acid esters such as wax, sazol wax and montanic acid ester wax; and those obtained by partially or fully deoxidizing fatty acid esters such as deoxidized carnauba wax. In addition, saturated linear fatty acids such as palmitic acid, stearic acid, and montanic acid; unsaturated fatty acids such as brassic acid, eleostearic acid, and valinalic acid; stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnauvir alcohol, and seryl alcohol Saturated alcohols such as melyl alcohol; long-chain alkyl alcohols; polyhydric alcohols such as sorbitol; fatty acid amides such as linoleic acid amide, oleic acid amide, and lauric acid amide; methylene bis stearic acid amide, ethylene biscaprin Saturated fatty acid bisamides such as acid amide, ethylene bislauric acid amide, hexamethylene bis stearic acid amide; ethylene bis oleic acid amide, hexamethylene bis oleic acid amide, N, N′-dioleyl Unsaturated fatty acid amides such as dipinamide, N, N-dioleyl sebacic acid amide; aromatic bisamides such as m-xylenebisstearic acid amide, N, N-distearylisophthalic acid amide; calcium stearate, laur Grafted with fatty acid metal salts such as calcium phosphate, zinc stearate, magnesium stearate (generally called metal soap), and aliphatic hydrocarbon waxes with vinyl monomers such as styrene and acrylic acid. Examples of waxes include partially esterified products of fatty acids such as behenic acid monoglyceride and polyhydric alcohols, and methyl ester compounds having hydroxyl groups obtained by hydrogenation of vegetable oils and the like.

  The amount of the release agent is 0.1 to 20 parts by mass, preferably 0.5 to 10 parts by mass per 100 parts by mass of the binder resin. In addition, these release agents can be contained in the binder resin usually by dissolving the resin in a solvent, increasing the resin solution temperature, adding and mixing with stirring, or mixing at the time of kneading.

  The magnetic substance used in the present invention is preferably a magnetic oxide such as magnetite, maghematite, ferrite, or a mixture thereof.

  For example, lithium, beryllium, boron, magnesium, aluminum, silicon, phosphorus, sulfur, germanium, titanium, zirconium, tin, lead, zinc, calcium, barium, vanadium, chromium, manganese, cobalt, copper, nickel, gallium, indium, Magnetic iron oxide containing at least one element selected from silver, palladium, gold, platinum, tungsten, molybdenum, niobium, osmium, strontium, yttrium, technetium, ruthenium, rhodium, bismuth and the like. Preference is given to lithium, beryllium, boron, magnesium, aluminum, silicon, phosphorus, germanium, titanium, zirconium, tin, sulfur, calcium, barium, vanadium, chromium, manganese, cobalt, copper, nickel, strontium, bismuth and zinc. Particularly preferred is magnetic iron oxide containing an element selected from magnesium, aluminum, silicon, phosphorus and zirconium as a different element. These elements may be incorporated into the iron oxide crystal lattice, may be incorporated into the iron oxide as an oxide, and may exist on the surface as an oxide or hydroxide, It is preferable to contain.

  These elements can be incorporated into the particles by mixing the salts of the respective elements at the time of magnetic substance production and adjusting the pH. Moreover, it can be made to deposit on the particle | grain surface by adjusting pH after magnetic body particle | grain production | generation, or adding salt of each element and adjusting pH.

  A magnetic material containing these elements generally has good affinity with a toner binder resin, and is more effective for a binder resin having a specific acid value. In addition, since the particle size distribution of these magnetic materials is narrow and the dispersibility in the binder resin is also good, it has the effect of improving the uniform charging and stabilization of the toner.

  The content of these different elements may be 0.05 to 10% by mass, preferably 0.1 to 7% by mass, particularly preferably 0, based on the iron element of the magnetic iron oxide. .2 to 5% by mass, and further 0.3 to 4% by mass. When the content is less than 0.05% by mass, there is no effect of containing these elements, and good dispersibility and charging uniformity cannot be obtained. On the other hand, if it exceeds 10% by mass, the discharge of electrification increases, resulting in insufficient charging, and this is not preferable because the image density decreases and fog increases.

  Further, in the distribution of the content of these different elements, it is preferable that they exist in the vicinity of the surface of the magnetic material. For example, when the dissolution rate of the iron element contained in the iron oxide is 20% by mass, the dissolution rate of the different element may be 20 to 100% by mass of the abundance of all the different elements, preferably 25 to 25%. It is a case where it becomes 100 mass%, Most preferably, it is a case where it becomes 30-100 mass%. By increasing the surface abundance of the different elements, the dispersion effect and the electrical diffusion effect can be further improved.

The number average particle size of these magnetic materials is preferably 0.05 to 1.0 μm, more preferably 0.1 to 0.5 μm. The BET specific surface area of the magnetic material is preferably ^{2 to} 40 m ² / g, more preferably 4 to ²⁰ m ² / g. Magnetic properties of the magnetic material, the saturation magnetization measured in a magnetic field 795.8 kA / m is preferably 10~200Am ² / kg, more 70~100Am ² / kg is more preferable. The remanent magnetization is preferably 1 to 100 Am ² / kg, more preferably ^{2 to 20} Am ² / kg. The coercive force is preferably 1 to 30 kA / m, and more preferably 2 to 15 kA / m. These magnetic materials are used by adding 20 to 200 parts by mass with respect to 100 parts by mass of the binder resin.

  Any suitable pigment or dye can be used as the colorant in the toner of the present invention. As the pigment, for example, carbon black, aniline black, acetylene black, naphthol yellow, hansa yellow, rhodamine yellow, alizarin yellow, bengara, phthalocyanine blue, etc. can be used. ˜20 parts by mass may be added, but preferably 0.2 to 10 parts by mass is added. Similarly, azo dyes, anthraquinone dyes, xanthene dyes, methine dyes, and the like can be used as the dye, and 0.1 to 20 parts by mass with respect to 100 parts by mass of the binder resin. What is necessary is just to add, Preferably it is adding 0.3-10 mass parts.

  A fluidity improver may be added to the toner of the present invention. The fluidity improver can be added to the toner particles to increase the fluidity before and after the addition. For example, fluororesin powder such as vinylidene fluoride fine powder, polytetrafluoroethylene fine powder; wet powder silica, fine powder silica such as dry process silica, fine powder titanium oxide, fine powder alumina, silane coupling agent, There are a titanium coupling agent, a treated silica surface-treated with silicone oil, and the like.

A preferable fluidity improver is a fine powder produced by vapor phase oxidation of a silicon halogen compound, and is called so-called dry silica or fumed silica. For example, a thermal decomposition oxidation reaction of silicon tetrachloride gas in an oxyhydrogen flame is used, and the basic reaction formula is as follows.
SiCl ₄ + 2H ₂ + O ₂ → SiO ₂ + 4HCl

  In this production process, it is also possible to obtain composite fine powders of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride or titanium chloride together with silicon halogen compounds. To do. The average primary particle size is preferably within a range of 0.001 to 2 μm, and particularly preferably a fine silica powder within a range of 0.002 to 0.2 μm is used. .

  Examples of commercially available silica fine powders produced by vapor phase oxidation of silicon halogen compounds include those sold under the following trade names.

  AEROSIL (Nippon Aerosil) 130, 200, 300, 380, TT600, MOX170, MOX80, COK84; Ca-O-SiL (CABOT Co.) M-5, MS-7, MS-75, HS-5, EH -5; (WACKER-CHEMIE GMBH) HDK, N20, 15, N20E, T30, T40; D-C Fine Silica (Dow Corning Co.); Francol (Fransil)

As a hydrophobizing method, it is applied by chemically treating with an organosilicon compound that reacts or physically adsorbs with silica fine powder. As a preferred method, silica fine powder produced by vapor phase oxidation of a silicon halogen compound is treated with an organosilicon compound.
Examples of organosilicon compounds include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, and bromomethyldimethyl. Chlorsilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyl Diethoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane, 1,3 -Diphenyltetramethyldisiloxane and dimethylpolysiloxane containing 2 to 12 siloxane units per molecule, each containing a hydroxyl group bonded to one Si at each terminal unit. Furthermore, silicone oils such as dimethyl silicone oil can be mentioned. These are used alone or in a mixture of two or more.

A fluidity improver having a specific surface area by nitrogen adsorption measured by the BET method of 30 m ² / g or more, preferably 50 m ² / g or more gives good results. The flow improver is used in an amount of 0.01 to 8 parts by weight, preferably 0.1 to 4 parts by weight, based on 100 parts by weight of the toner.

  As for the degree of hydrophobicity of the inorganic fine powder used in the toner of the present invention, methanol wettability may be 30% or more, preferably 50% or more. As the hydrophobizing agent, a silane compound and silicone oil which are silicon-containing surface treating agents are preferable.

  For example, dimethyldimethoxysilane, trimethylethoxysilane, butyltrimethoxysilane, alkylalkoxysilane; dimethyldichlorosilane, trimethylchlorosilane, allyldimethylchlorosilane, hexamethylenedimethylchlorosilane, allylphenyldimethylchlorosilane, benzyldimethylchlorosilane Silane coupling agents such as vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, divinylchlorosilane, and dimethylvinylchlorosilane can be used.

In the toner of the present invention, various additives can be used for the purpose of imparting various properties. For example, the following additives are used.
(1) As abrasives, metal oxides (strontium titanate, cerium oxide, aluminum oxide, magnesium oxide, chromium oxide, etc.), nitrides (silicon nitride, etc.), carbides (silicon carbide, etc.), metal salts (calcium sulfate, etc.) , Barium sulfate, calcium carbonate, etc.).
(2) Examples of the lubricant include fluorine resin powder (polyvinylidene fluoride, polytetrafluoroethylene, etc.), aliphatic metal salts (zinc stearate, calcium stearate, etc.) and the like.
(3) Examples of the charge controllable particles include metal oxides (tin oxide, titanium oxide, zinc oxide, silicon oxide, aluminum oxide, etc.), carbon black, resin particles, and the like.

  These additives are added in an amount of 0.05 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the toner particles. These additives may be used alone or in combination. However, it is necessary to adjust the addition amount and control the compression index.

  In the case of a magnetic toner, it is preferable to use fine powders of two or more kinds of inorganic oxides or metal oxides from the viewpoint of durability of development and development stability after standing. In the case of the non-magnetic one-component development method, it is preferable to use titanium oxide or alumina from the viewpoint of improving fluidity and image uniformity.

  In order to produce the toner of the present invention, binder resin, colorant, other additives, etc. are sufficiently mixed by a mixer such as a Henschel mixer or a ball mill and then heat kneaded such as a heating roll, a kneader or an extruder. The toner of the present invention can be obtained by melt-kneading using a machine, performing pulverization and classification after cooling and solidification, and further sufficiently mixing a desired additive with a mixer such as a Henschel mixer if necessary.

  In particular, it is preferable to adjust the pulverization step in controlling the shape of the coarse particles of the toner.

  Examples of the mixer include Henschel mixer (manufactured by Mitsui Mining); Super mixer (manufactured by Kawata); Ribocorn (manufactured by Okawara Seisakusho); Nauter mixer, turbulizer, cyclomix (manufactured by Hosokawa Micron); (Manufactured by Taiheiyo Kiko Co., Ltd.); Ladige mixer (manufactured by Matsubo Co., Ltd.), and kneaders: KRC kneader (manufactured by Kurimoto Iron Works Co.); bus co kneader (manufactured by Buss); TEM type extruder (Manufactured by Toshiba Machine Co., Ltd.); TEX twin-screw kneader (manufactured by Nippon Steel Works); PCM kneader (manufactured by Ikegai Iron Works Co., Ltd.); three roll mill, mixing roll mill, kneader (manufactured by Inoue Seisakusho Co., Ltd.); Mining company); MS pressure kneader, Nider Ruder (Moriyama Seisakusho); Banbury mixer (Kobe Steel) As a pulverizer, a counter jet mill, a micron jet, an inomizer (manufactured by Hosokawa Micron Co.); an IDS type mill, a PJM jet pulverizer (manufactured by Nippon Pneumatic Industry Co., Ltd.); a cross jet mill (manufactured by Kurimoto Iron Works Co., Ltd.); ULMAX (manufactured by Nisso Engineering Co., Ltd.); SK Jet O Mill (manufactured by Seishin Enterprise Co., Ltd.); Kryptron (manufactured by Kawasaki Heavy Industries Co., Ltd.); turbo mill (manufactured by Turbo Kogyo Co., Ltd.). , Micron Classifier, Spedic Classifier (manufactured by Seishin Enterprise Co., Ltd.); Turbo Classifier (Nisshin Engineering Co., Ltd.); Micron Separator, Turboplex (ATP), TSP Separator (manufactured by Hosokawa Micron Co.); ), Disper Separator separator (manufactured by Nippon Pneumatic Co., Ltd.); YM Microcut (manufactured by Yaskawa Shoji Co., Ltd.) is listed. Ultrasonic (manufactured by Sakae Sangyo Co., Ltd.); Resona sieve , Gyroshifter (Tokuju Kogakusha); Vibrasonic system (Dalton); Soniclean (Shinto Kogyo); Turbo screener (Turboe); Micro shifter (Ogino Sangyo); Circular vibration A sieve etc. are mentioned.

  In particular, a mechanical pulverizer that is preferably used as a pulverizing means used in a method for producing toner having a controlled coarse particle shape as in the present invention will be described. Examples of the mechanical pulverizer include a pulverizer inomizer manufactured by Hosokawa Micron Co., Ltd., a pulverizer KTM manufactured by Kawasaki Heavy Industries, Ltd., and a turbo mill manufactured by Turbo Industry Co., Ltd. Are preferably used.

  In the present invention, among these, the mechanical pulverizer as shown in FIGS. 1, 2 and 3 can be used to easily control the shape of coarse particles and pulverize the powder raw material. Efficiency is improved, which is preferable.

  Hereinafter, the mechanical pulverizer shown in FIGS. 1, 2 and 3 will be described. FIG. 1 shows a schematic cross-sectional view of an example of a mechanical pulverizer used in the present invention, FIG. 2 shows a schematic cross-sectional view along the line DD ′ in FIG. 1, and FIG. The perspective view of the rotor 314 shown in FIG. 1 is shown. As shown in FIG. 5, the apparatus has a large number of grooves on a surface that rotates in a casing 313, a jacket 316, a distributor 220, a casing 313, and a rotating body that is attached to a central rotating shaft 312. The provided rotor 314, the stator 310 provided with a large number of grooves on the outer periphery of the rotor 314, which are arranged at regular intervals, and the raw material input for introducing the raw material to be treated The port 311 includes a raw material discharge port 302 for discharging the processed powder.

  The pulverization operation in the mechanical pulverizer configured as described above is performed, for example, as follows.

  That is, when a predetermined amount of powder raw material is introduced from the powder inlet 311 of the mechanical pulverizer shown in FIG. 1, the particles are introduced into the pulverization chamber and are rotated on the surface rotating at high speed in the pulverization chamber. The impact generated between the rotor 314 provided with a large number of grooves and the stator 310 provided with a large number of grooves on the surface, a large number of ultrahigh-speed vortices generated behind this, and the generated It is crushed instantaneously by high-frequency pressure vibration. Thereafter, the material passes through the material discharge port 302 and is discharged. The air carrying the toner particles passes through the pulverization chamber and is discharged out of the apparatus system through the material discharge port 302, the pipe 219, the collecting cyclone 229, the bag filter 222, and the suction filter 224. Is done. In the present invention, since the powder raw material is pulverized in this manner, a desired pulverization treatment can be easily performed without increasing the fine powder and coarse powder. By adjusting the flow rate of the carrier air, the shape of the coarse particles of the toner particles can be controlled.

  In addition, when the pulverized raw material is pulverized by a mechanical pulverizer, it is preferable that cold air is blown into the mechanical pulverizer together with the powder raw material by the cold air generating means 321. Further, the temperature of the cold air is preferably 0 to -18 ° C. Further, as an in-machine cooling means of the mechanical pulverizer body, the mechanical pulverizer preferably has a structure having a jacket structure 316, and it is preferable to pass cooling water (preferably an antifreeze such as ethylene glycol). Furthermore, due to the cold air device and the jacket structure described above, the room temperature T1 in the spiral chamber 212 communicating with the powder inlet in the mechanical pulverizer is 0 ° C. or less, more preferably −5 to −15 ° C., still more preferably −7. It is preferable to set the temperature to -12 ° C from the viewpoint of toner productivity. By setting the room temperature T1 of the swirl chamber in the pulverizer to 0 ° C. or less, more preferably −5 to −15 ° C., and still more preferably −7 to −12 ° C., surface modification of the toner due to heat can be suppressed, and efficiency The pulverized raw material can be pulverized well. When the room temperature T1 of the swirl chamber in the pulverizer exceeds 0 ° C., it is not preferable from the viewpoint of toner productivity because the surface of the toner is easily deteriorated or fused in the machine during pulverization. Further, if the room temperature T1 of the spiral chamber in the pulverizer is to be operated at a temperature lower than −15 ° C., the refrigerant (alternative chlorofluorocarbon) used in the cold air generating means 321 must be changed to chlorofluorocarbon.

  Currently, chlorofluorocarbons are being eliminated from the viewpoint of protecting the ozone layer. Use of chlorofluorocarbon as the refrigerant of the cold air generating means 321 is not preferable from the viewpoint of global environmental problems.

  Alternative CFCs include R134A, R404A, R407C, R410A, R507A, R717, etc. Among them, R404A is particularly preferable from the viewpoint of energy saving and safety.

  The cooling water (preferably an antifreeze such as ethylene glycol) is supplied into the jacket from the cooling water supply port 317 and discharged from the cooling water discharge port 318.

  The finely pulverized product generated in the mechanical pulverizer is discharged from the powder discharge port 302 to the outside through the rear chamber 320 of the mechanical pulverizer. At this time, the room temperature T2 of the rear chamber 320 of the mechanical pulverizer is preferably 30 to 60 ° C. from the viewpoint of toner productivity. By setting the room temperature T2 of the rear chamber 320 of the mechanical pulverizer to 30 to 60 ° C., it is possible to suppress the toner surface deterioration due to heat and to efficiently pulverize the pulverized raw material. When the temperature T2 of the mechanical pulverizer is lower than 30 ° C., there is a possibility of causing a short pass without being pulverized, which is not preferable from the viewpoint of toner performance. On the other hand, when the temperature is higher than 60 ° C., it may be excessively pulverized at the time of pulverization, and it is not preferable from the viewpoint of toner productivity because the surface of the toner is easily deteriorated or melted in the machine.

  Further, when the pulverized raw material is pulverized by a mechanical pulverizer, the temperature difference ΔT (T2−T1) between the room temperature T1 of the spiral chamber 212 and the room temperature T2 of the rear chamber 320 of the mechanical pulverizer is set to 40 to 70 ° C. The temperature is preferably 42 to 67 ° C., more preferably 45 to 65 ° C. from the viewpoint of toner productivity. By setting ΔT between the temperature T1 and the temperature T2 of the mechanical pulverizer to 40 to 70 ° C., more preferably 42 to 67 ° C., and further preferably 45 to 65 ° C., the surface deterioration of the toner due to heat can be suppressed. Thus, the pulverized raw material can be efficiently pulverized. When ΔT between the temperature T1 and the temperature T2 of the mechanical pulverizer is smaller than 40 ° C., there is a possibility that a short pass is caused without being pulverized, which is not preferable from the viewpoint of toner performance. On the other hand, when the temperature is higher than 70 ° C., the toner may be excessively pulverized at the time of pulverization, and it is not preferable from the viewpoint of toner productivity because the surface of the toner is easily deteriorated or melted in the machine.

  Further, when the pulverized raw material is pulverized with a mechanical pulverizer, the glass transition point (Tg) of the binder resin is preferably 45 to 75 ° C., more preferably 55 to 65 ° C. Further, it is preferable from the viewpoint of toner productivity that the room temperature T1 of the spiral chamber 212 of the mechanical pulverizer is 0 ° C. or less with respect to Tg and 60 to 75 ° C. lower than Tg. By changing the room temperature T1 of the spiral chamber 212 of the mechanical pulverizer to 0 ° C. or lower and 60 to 75 ° C. lower than Tg, it is possible to suppress the toner surface alteration due to heat, and to efficiently pulverize the pulverized raw material. Can do. The room temperature T2 of the rear chamber 320 of the mechanical pulverizer is preferably 5 to 30 ° C., more preferably 10 to 20 ° C. lower than Tg. By changing the room temperature T2 of the rear chamber 320 of the mechanical pulverizer to 5 to 30 ° C., more preferably 10 to 20 ° C. lower than Tg, toner surface deterioration due to heat can be suppressed, and the pulverized raw material can be efficiently pulverized. can do.

  Further, the tip peripheral speed of the rotating rotor 314 is preferably 80 to 180 m / sec, more preferably 90 to 170 m / sec, and further preferably 100 to 160 m / sec in terms of toner productivity. To preferred. By setting the peripheral speed of the rotating rotor 314 to 80 to 180 m / sec, more preferably 90 to 170 m / sec, and even more preferably 100 to 160 m / sec, insufficient pulverization and excessive pulverization of the toner can be suppressed. The pulverized raw material can be pulverized efficiently. When the peripheral speed of the rotor is lower than 80 m / sec, a short pass is easily caused without being pulverized, which is not preferable from the viewpoint of toner performance. Further, when the peripheral speed of the rotor 314 is higher than 180 m / sec, the load on the apparatus itself increases, and at the same time, the toner is excessively pulverized at the time of pulverization and is liable to cause toner surface deterioration and in-machine fusion. It is not preferable from the point.

  The minimum distance between the rotor 314 and the stator 310 is preferably 0.5 to 10.0 mm, more preferably 1.0 to 5.0 mm, and still more preferably 1.0 to 3.0 mm. It is preferable that By setting the distance between the rotor 314 and the stator 310 to 0.5 to 10.0 mm, more preferably 1.0 to 5.0 mm, and still more preferably 1.0 to 3.0 mm, the toner is pulverized. Insufficient or excessive grinding can be suppressed, and the grinding raw material can be efficiently ground. If the distance between the rotor 314 and the stator 310 is larger than 10.0 mm, it is not preferable from the viewpoint of toner performance because a short pass is likely to occur without being pulverized. Further, when the distance between the rotor 314 and the stator 310 is smaller than 0.5 mm, the load on the apparatus itself increases, and at the same time, the toner is excessively pulverized during pulverization and is liable to cause toner surface alteration and in-machine fusion. Therefore, it is not preferable from the viewpoint of toner productivity.

  Since this pulverization method has a simple structure and does not require a large amount of air to pulverize the pulverized raw material, the amount of power consumed per 1 kg of toner consumed in the pulverization process is the same as the conventional collision shown in FIG. The energy cost can be kept low because it is about 1/3 or less of that produced by the airflow crusher.

  The measurement method in the present invention will be described below.

(1) Measuring method of average circularity of toner and equivalent circle system The average circularity of the present invention is used as a simple method capable of quantitatively expressing the shape of the particles. In the present invention, flow type particles manufactured by Simex Corporation are used. Measurement is performed using an image analyzer FPIA 2100, and the equivalent circle diameter of the measured particle is obtained by the following equation (1), and the circularity is obtained by the following equation (2) and measured as shown by the following equation (3). The total circularity of all particles was defined as the average circularity.

  The circularity used in the present invention is an index of the degree of unevenness of the toner particles, and indicates 1.00 when the toner is a perfect sphere. The more complicated the surface shape, the smaller the circularity. Further, the circularity distribution SD in the present invention is an index of variation, and the smaller the numerical value, the smaller the variation in toner shape.

  In addition, “FPIA-2100”, which is a measuring apparatus used in the present invention, calculates the circularity of each particle, and then calculates the average circularity and the circularity standard deviation. The degree 0.4 to 1.0 is divided into 61 classes, and a calculation method is used in which the average circularity and the circularity standard deviation are calculated using the center value and frequency of the dividing points. However, the average circularity calculated by this calculation method and the average circularity error calculated by the calculation formula that directly uses the circularity of each particle described above are very small, and are practically negligible. In the present invention, for the reason of handling data such as shortening the calculation time and simplifying the calculation formula, the concept of the calculation formula that directly uses the circularity of each particle described above is used, and this is partially changed. Such a calculation method may be used. Furthermore, the measurement device used in the present invention, “FPIA-2100”, has a thinner sheath flow (7 μm → 4 μm) than “FPIA1000” which has been used to calculate the shape of the toner. ) And the magnification of the processed particle image, and further improved the processing resolution of the captured image (256 × 256 → 512 × 512), so that the accuracy of toner shape measurement has been improved, thereby more reliably capturing fine particles. It is a device that has achieved. Therefore, when it is necessary to measure the shape more accurately as in the present invention, the FPIA 2100 that can obtain information on the shape more accurately is more useful.

  As a specific measuring method, a surfactant, preferably an alkylbenzene sulfonate, is used as a dispersant in 100 to 150 ml of water from which impurities in the container have been removed in advance at room temperature and humidity (23 ° C., 50% RH). 0.1 to 0.5 ml is added, and about 0.1 to 0.5 g of a measurement sample is further added. Using an ultrasonic disperser “Tetora150 type” (manufactured by Nikka Ki Bios), ultrasonic waves (50 kHz, 120 W) are irradiated for 2 minutes to obtain a dispersion for measurement. In that case, it cools suitably so that the temperature of this dispersion may not be 40 degreeC or more.

  The circularity distribution of particles having a circle-equivalent diameter of 0.60 μm or more and less than 159.21 μm is measured using the above flow type particle image measurement apparatus at a dispersion concentration of 1.2 to 2 million particles / μl.

  The outline of the measurement is as follows.

  The sample dispersion is passed through a flow path (expanded along the flow direction) of a flat and flat flow cell (thickness: about 200 μm). The strobe and the CCD camera are mounted on the flow cell so as to be opposite to each other so as to form an optical path that passes through the thickness of the flow cell. While the sample dispersion is flowing, strobe light is irradiated at 1/30 second intervals to obtain an image of the particles flowing through the flow cell, so that each particle has a certain range parallel to the flow cell. Photographed as a two-dimensional image. From the area of the two-dimensional image of each particle, the diameter of a circle having the same area is calculated as the equivalent circle diameter. The circularity of each particle is calculated from the projected area of the two-dimensional image of each particle and the perimeter of the projected image using the above circularity calculation formula.

  Using the data obtained by this method, after cutting the equivalent circle diameter of less than 3.00 μm, the average circularity of the entire magnetic toner in the present invention is 30% on the coarse particle side average circularity on the basis of the number of equivalent circle diameters and A cumulative value based on the number of particles having a circularity of 0.920 or more is calculated.

(2) Measurement of Acid Value of Charge Control Agent The “acid value” of the charge control agent is determined as follows. Basic operation conforms to JIS-K0070.

  The number of mg of potassium hydroxide required to neutralize free fatty acids, resin acids, etc. contained in 1 g of the sample is called the acid value, and the test is conducted as follows.

a. Reagent 0.1 mol / L potassium hydroxide methanol solution, methanol (reagent grade 1), acetone (reagent grade 1), toluene, bromthymol blue (BTB indicator), phenolphthalein (PP indicator)
b. Equipment / instrument Potentiometric titrator (Example equipment; AT-117 manufactured by Kyoto Electronics)
200ml beaker, rotor, stirrer, chemical balance (0.1mg unit)
c. Operation 1) Mix 1 L of methanol and 1 L of acetone, add 1 drop of BTB, add 30 ml of phenolphthalein, and then add 0.1 mol / L potassium hydroxide methanol solution until it becomes slightly reddish purple.
2) Precisely weigh about 1 g of sample in a 200 ml beaker (Sg), add 50 ml of toluene and 50 ml of the above mixed solution, and stir with a rotor to dissolve evenly.
3) Potentiometric titration with 0.1 mol / L potassium hydroxide methanol solution (titer = f).
4) The titer (Aml) from the start of titration to the first inflection point and the titer (Bml) from the start of titration to the second inflection point are determined and calculated by the following equation.
First acid value A = 5.61 × f × A / S
Second acid number B = 5.61 × f × B / S

(3) Measurement of Acid Value of Resin The “acid value” of the binder resin is determined as follows. Basic operation conforms to JIS-K0070.

  The number of mg of potassium hydroxide required to neutralize free fatty acids, resin acids, etc. contained in 1 g of the sample is called the acid value, and the test is conducted as follows.

1) Reagent (a) Solvent ethyl ether-ethyl alcohol mixed solution (1 + 1 or 2 + 1) or benzene-ethyl alcohol mixed solution (1 + 1 or 2 + 1), which is N / 10 potassium hydroxide with phenolphthalein as an indicator immediately before use. Neutralize with ethyl alcohol solution.
(B) Phenolphthalein solution 1 g of phenolphthalein is dissolved in 100 ml of ethyl alcohol (95 v / v%).
(C) N / 10 potassium hydroxide-ethyl alcohol solution Dissolve 7.0 g of potassium hydroxide in as little water as possible, add ethyl alcohol (95 v / v%) to 1 liter, leave it for 2 to 3 days, and filter. The standardization is performed according to JIS K 8006 (basic matters concerning titration during the reagent content test).

  2) Operation Weigh correctly 1 to 20 g of sample, add 100 ml of solvent and a few drops of phenolphthalein solution as an indicator, and shake well until the sample is completely dissolved. In the case of a solid sample, dissolve it by heating on a water bath. After cooling, this is titrated with an N / 10 potassium hydroxide ethyl alcohol solution, and the end point of neutralization is defined as the time when the indicator is slightly red for 30 seconds.

  3) Calculation formula The acid value is calculated by the following formula.

［Ａ：酸価
Ｂ：Ｎ／１０水酸化カリウムエチルアルコール溶液の使用量（ｍｌ）
Ｃ：Ｎ／１０水酸化カリウムエチルアルコール溶液のファクター
Ｓ：試料（ｇ） ］

[A: acid value B: amount of N / 10 potassium hydroxide ethyl alcohol solution used (ml)
C: Factor of N / 10 potassium hydroxide ethyl alcohol solution S: Sample (g)]

(3) Measurement of the hydroxyl value of the binder resin The “hydroxyl value” of the binder resin is determined as follows. The basic operation conforms to JIS = K0070.

  When 1 g of a sample is acetylated by a prescribed method, the number of mg of potassium hydroxide required to neutralize acetic acid bonded to a hydroxyl group is referred to as a hydroxyl value, and the test is performed by the following reagents, operations and calculation formulas.

1) Reagent (a) Acetylation reagent 25 g of acetic anhydride is placed in a 100 ml volumetric flask, pyridine is added to make a total volume of 100 ml, and shaken sufficiently (in some cases, pyridine may be added). The acetylating reagent should be kept away from moisture, carbon dioxide and acid vapors and stored in a brown bottle.
(B) Phenolphthalein solution 1 g of phenolphthalein is dissolved in 100 ml of ethyl alcohol (95 v / v%).
(C) N / 2 potassium hydroxide-ethyl alcohol solution Dissolve 35 g of potassium hydroxide in as little water as possible, add ethyl alcohol (95 v / v%) to 1 liter, leave it for 2 to 3 days, and filter. The orientation is performed according to JIS K 8006.

2) Operation 0.5-2.0 g of a sample is correctly weighed in a round bottom flask, and 5 ml of an acetylating reagent is correctly added thereto. Put a small funnel over the mouth of the flask and immerse the bottom of about 1 cm in a glycerin bath at 95-100 ° C. and heat. At this time, in order to prevent the temperature of the neck of the flask from rising due to the heat of the bath, a cardboard disc with a round hole in it is put on the base of the neck of the flask. After 1 hour, the flask is removed from the bath, and after cooling, 1 ml of water is added from the funnel and shaken to decompose acetic anhydride. In order to further complete the decomposition, the flask was again heated in a glycerin bath for 10 minutes, allowed to cool, and then the funnel and the wall of the flask were washed with 5 ml of ethyl alcohol, and N / 2 potassium hydroxide ethyl alcohol using a phenolphthalein solution as an indicator. Titrate with solution. A blank test is performed in parallel with the main test. In some cases, a KOH-THF solution may be used as an indicator.

  3) Calculation formula The hydroxyl value is calculated by the following formula.

［Ａ：水酸基価
Ｂ：空試験のＮ／２水酸化カリウムエチルアルコール溶液の使用量（ｍｌ）
Ｃ：本試験のＮ／２水酸化カリウムエチルアルコール溶液の使用量（ｍｌ）
ｆ：Ｎ／２水酸化カリウムエチルアルコール溶液のファクター
Ｓ：試料（ｇ）
Ｄ：酸価 ］

[A: Hydroxyl value B: Amount used of N / 2 potassium hydroxide ethyl alcohol solution in blank test (ml)
C: Amount of use of N / 2 potassium hydroxide ethyl alcohol solution in this test (ml)
f: Factor of N / 2 potassium hydroxide ethyl alcohol solution S: Sample (g)
D: Acid value]

(4) Molecular weight distribution by GPC measurement of toner and binder resin component The molecular weight distribution by GPC in the resin component of toner and binder resin is as follows. And measured by GPC.

  That is, the toner is put in THF, left for several hours, and then sufficiently shaken to mix well with THF (until the sample is no longer united), and then left to stand for 12 hours or more. At this time, the standing time in THF is set to be 24 hours or longer. Thereafter, a sample processing filter (pore size 0.45 to 0.5 μm, for example, Mysori Disc H-25-5 manufactured by Tosoh Corporation, Excro Disc 25CR manufactured by Gelman Science Japan Co., Ltd., etc.) can be used. A sample of GPC is used. The sample concentration is adjusted so that the resin component is 0.5 to 5 mg / ml.

The GPC measurement of the sample prepared by the above method was performed by stabilizing the column in a heat chamber at 40 ° C., and flowing tetrahydrofuran (THF) as a solvent at a flow rate of 1 ml / min as a solvent at this temperature. About 50 to 200 μl of a THF sample solution of resin adjusted to 0.05 to 0.6% by mass is injected and measured. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts (retention time). Examples of standard polystyrene samples for preparing a calibration curve include those manufactured by Tosoh Corporation or Pressure Chemical Co. The molecular weights manufactured are 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ⁴ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , 3.9 × 10 ⁵ , 8 ^{.6 × 10 5, 2 × 10} 6, used as a 4.48 × 10 ^6, it is appropriate to use at least about 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector.

As a column, in order to accurately measure a molecular weight region of 10 ^{3 to} 2 × 10 ⁶ , it is preferable to combine a plurality of commercially available polystyrene gel columns. For example, shodex GPC KF-801, 802, 803 manufactured by Showa Denko KK , 804, 805, 806, and 807, and combinations of μ-styragel 500, 10 ³ , 10 ⁴ , and 10 ⁵ manufactured by Waters.

(5) Measurement of toner particle size distribution In the present invention, the average particle size and particle size distribution of toner are measured using a Coulter Counter TA-II type (manufactured by Coulter), but a Coulter Multisizer (manufactured by Coulter) may also be used. Is possible. As the electrolytic solution, a 1% NaCl aqueous solution is prepared using primary sodium chloride. For example, ISOTON R-II (manufactured by Coulter Scientific Japan) can be used. As a measuring method, 0.1 to 5 ml of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution, and 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion process for about 1 to 3 minutes with an ultrasonic disperser, and the volume and the number of toners of 2.00 μm or more are measured by using the 100 μm aperture as the aperture by the measuring device. Distribution and number distribution were calculated. Then, the weight average particle diameter (D4) obtained from the volume distribution according to the present invention (the median value of each channel is a representative value for each channel) was obtained.

  As channels, 2.00 to 2.52 μm; 2.52 to 3.17 μm; 3.17 to 4.00 μm; 4.00 to 5.04 μm; 5.04 to 6.35 μm; 6.35 to 8. 00 μm; 8.00 to 10.08 μm; 10.08 to 12.70 μm; 12.70 to 16.00 μm; 16.00 to 20.20 μm; 20.20 to 25.40 μm; 25.40 to 32.00 μm; 13 channels of 32.00-40.30 μm are used.

  The best embodiment of the image forming method of the present invention will be described in detail with reference to FIG.

  The developing device includes a developing sleeve roller 2 that is a magnetic toner carrier rotatably disposed in an opening of the developing container 1, a clearance of 100 to 300 μm with the magnet roller 3 and the developing sleeve roller 2 inside the developing sleeve roller 2. A developer-thickening means for supplying a developer to the developing sleeve roller, which is disposed below the developing sleeve roller 2. A rotatable agitation paddle 5 and a conveying screw 6 for conveying toner from the toner container to the agitation paddle 5 in the developing container 1.

  The stirring paddle 5 is provided with a stirring blade 7 that is an elastic sheet of a nonmagnetic elastic member such as Mylar. Insufficient amount of toner is replenished by the toner conveying screw 6 so that the amount of toner in the developing device is constant. The replenished toner in the developing device is spun up by the counterclockwise rotation operation and elastic force of the stirring blade 7 of the nonmagnetic member provided in the stirring paddle 5 which is agitating and conveying member, The toner is collected by the developing roller 2 provided with a magnet roller 3 that rotates in the direction. Further, the magnetic toner in the vicinity of the developer sleeve roller 2 is scraped and stirred by the tip portion of the elastic sheet 7. The collected toner remaining after scraping is transported and accumulated in the layer thickness regulating blade 4 by the rotation of the developing sleeve roller 2 to accumulate electric charge. The toner collected on the surface of the developing sleeve roller 2 develops the latent image formed on the photosensitive drum and visualizes it.

Further, in the present invention, the shortest distance La (mm) from the rotation center of the agitation / conveyance member of the developing container to the surface of the sleeve roller, which is a magnetic toner carrier, in FIG. When the length to the tip of the stirring blade is Lb (mm), 1 <La-Lb <8.0
It is preferable to make the charging of the toner in the developing unit, particularly in the vicinity of the developing sleeve roller uniform.

  (La-Lb), that is, when the closest distance between the tip of the stirring blade and the surface of the developing sleeve roller is less than 0.1 mm, the tip of the stirring blade easily damages the developing sleeve. When the amount of toner to be held on the roller is reduced and images with a large image ratio are output continuously, white spots or the like are likely to occur.

  On the other hand, when (La−Lb) exceeds 8.0 (mm), the toner in the vicinity of the developing sleeve is not sufficiently stirred, and the charging is likely to be non-uniform and image unevenness and fogging are likely to occur.

In the present invention, the rotation speed R1 (rpm) of the stirring and conveying member and the rotation speed R2 (rpm) of the magnetic toner carrier are 2 × R1 <R2 <12 × R1 (preferably 4 × R1 <R2 < 10 × R1) is preferable in order to stably supply the toner to the developing sleeve roller. When 2 × R1> R2, the toner supply to the developing sleeve roller becomes excessive, and the toner is easily pressed and packed in the vicinity of the developing sleeve roller by the rotation of the stirring / conveying member, thereby generating a toner immobile layer, Not only does the toner circulation deteriorate and toner charging unevenness is likely to occur, but the toner is pressed against the developing sleeve roller for a long period of time, and the toner component adheres to the developing sleeve roller and contaminates the developing sleeve. There are many.

  Further, when R2> 12 × R1, insufficient supply of toner to the developing sleeve roller is likely to occur, and the number of contact between the stirring blade and the toner in the vicinity of the sleeve roller is reduced. A difference in charge amount tends to occur between the newly supplied toner and image defects such as image unevenness and fog.

  In the present invention, it is preferable that the tip of the stirring blade and the wall of the developing container have a certain distance.

  When the distance between the tip of the agitating / conveying member and the container wall is large, the toner remains on the developing container wall, and the circulation of the toner in the developing container tends to be impaired. In addition, when the tip of the agitating / conveying member comes into contact with the container wall, the toner is damaged at the contact portion, and the toner is agglomerated and coagulated to easily generate toner coarse particles. It is easily caught between the blade and the developing sleeve, causing damage to the surface of the developing sleeve or causing contamination.

  FIG. 7 is a view showing a sheet-like rotating body having a certain width in the longitudinal direction of the present invention.

  The stirring shaft is a rod-like member, and is held so as to be rotatable by a shaft support hole provided in the side wall of the developing container. As a method for joining the stirring shaft and the stirring blade, a conventional method such as snap fitting, heat caulking, screwing, or the like may be used. In addition, it is preferable that the ribs are erected in the direction perpendicular to the rotation axis in order to assist the sheet-like stirring member.

  In addition, as a material constituting the sheet-like stirring / conveying member, a material having appropriate elasticity and creep resistance can be used. For example, polyacetal, a polyurethane rubber sheet, a rubberized cloth, or the like may be used. Is a polyester (PET) film. The thickness is preferably about 30 μm to 500 μm, particularly preferably about 50 μm to 200 μm. If the thickness is less than about 30 μm, the elasticity becomes weak and the toner conveying force is reduced. If the thickness is more than about 500 μm, the elasticity becomes too strong and a large rotational torque is required for rotation or deformation occurs. Since it is difficult, there are problems such as difficulty in assembling. In the present embodiment, the thickness is 100 μm.

  Here, as the magnetic toner carrier that can be used in the present invention, for example, a metal, an alloy thereof, or a compound thereof is formed into a cylindrical shape, and the surface thereof is subjected to a predetermined surface roughness by electrolysis, blast, file, or the like. What was processed so that it may become is used. As the material of the sleeve base, for example, stainless steel, aluminum, a trunk alloy or the like can be used. The surface may be coated with a metal plating process or a resin layer as necessary. In order to obtain a desired surface roughness on the surface of the support, blasting may be performed with spherical particles such as alumina particles or glass beads.

  When the sleeve base is coated with a resin, the binder resin for coating is phenolic resin, epoxy resin, polyamide resin, polyester resin, polycarbonate resin, polyolefin resin, silicone resin, fluorine resin, styrene Resins such as acrylic resins and acrylic resins are used. In particular, a thermosetting or photocurable resin is preferable.

  Moreover, you may contain an electroconductive substance, a filler, a solid lubricant, etc. other than binder resin as needed.

In the sleeve of the present invention, when the conductive material is contained in the resin layer, the volume resistance of the resin layer is 10 ⁶ Ω · cm or less, preferably 10 ³ Ω · cm or less. When the volume resistance of the resin layer exceeds 10 ⁶ Ω · cm, the toner is likely to be charged up, which may cause blotches and deteriorate development characteristics.

  Examples of the conductive material include metal powders such as aluminum, copper, nickel, and silver; metal oxides such as antimony oxide, indium oxide, and tin oxide; and carbon allotropes such as carbon fiber, carbon black, and graphite.

  As the filler, a known negatively chargeable charge control agent for toner or a positively chargeable charge control agent may be added. Examples of other substances include inorganic compounds such as alumina, asbestos, glass fiber, calcium carbonate, magnesium carbonate, barium carbonate, barium sulfate, silica, and calcium silicate; phenol resin, epoxy resin, melamine resin, silicone resin, PMMA, Methacrylate terpolymers (eg polystyrene / n-butyl methacrylate / silane terpolymers), styrene-butadiene copolymers, polycaprolactones; nitrogen-containing compounds such as polycaprolactam, polyvinylpyridine, polyamide; polyvinylidene fluoride, polyvinyl chloride, Polytetrafluoroethylene, polytetrachlorofluoroethylene, perfluoroalkoxylated ethylene, polytetrafluoroalkoxyethylene, fluorinated ethylene propylene-polyte Fluoroethylene copolymers, trifluorochloroethylene - polymers were highly halogenated such vinyl chloride copolymers; polycarbonates, and polyester.

  Examples of the solid lubricant include molybdenum disulfide, boron nitride, graphite, graphite fluoride, silver-niobium selenide, calcium chloride-graphite, and talc. Of these, graphite is preferably used because it has conductivity as well as lubricity, has a function of reducing toner having an excessively high charge, and having a charge amount suitable for development.

  Further, the toner layer thickness regulating blade that can be used in the present invention includes a metal blade, a magnetic blade, or an elastic blade that is brought into contact with the surface of the developing sleeve with an elastic force with a certain gap from the developing sleeve. Either is possible.

  In the case of a metal blade or a magnetic blade, good results are obtained when the gap with the developing sleeve is 50 to 500 μm, preferably 100 to 400 μm.

  Specific examples of the present invention will be described below, but the present invention is not limited to these examples.

[Production example of charge control agent]
(Production Example 1 of Charge Control Agent)
286 parts by mass of isopropyl alcohol is charged into a reaction vessel equipped with a thermometer, a cooling pipe, a stirrer, and a nitrogen introduction pipe, and 800 parts by mass of styrene, 130 parts by mass of 2-ethylhexyl acrylate, 2-acrylamido-2-methylpropanesulfonic acid. A mixed suspension solution of 70 parts by mass, 400 parts by mass of isopropyl alcohol and 2575 parts by mass of water, and a mixed solution of 755 parts by mass of methyl ethyl ketone and 35 parts by mass of azobis (2-methylbutyronitrile) at 78 ° C. over 2 hours. At the same time, it was dropped and polymerized.

  Further, after aging at the same temperature for 4 hours, isopropyl alcohol and methyl ethyl ketone were distilled off, followed by solid-liquid separation and drying to obtain a charge control agent (S1). The time required for phase separation during the polymerization was 200 seconds.

  The first acid value of S1 is 7.8 mgKOH / g, the second acid value is 11.6 mgKOH / g, the weight average molecular weight (Mw) is 28000, the number average molecular weight (Mn) is 12000, and the glass transition point (Tg). Was 80.2 ° C.

(Production Examples of Charge Control Agents 2 to 6)
The charge control agents S2 to S6 were the same as the charge control agent Production Example 1 except that the number of additions of styrene, 2-ethylhexyl acrylate and 2-acrylamido-2-methylpropanesulfonic acid and the polymerization time were changed. Got. Table 1 shows the physical properties of the obtained charge control agent.

[Example of binder resin production]
(Resin production example 1)
(Hybrid resin)
(1) Manufacture of polyester resin, terephthalic acid: 6.1 mol
・ Dodecenyl succinic anhydride: 3.8 mol
・ Trimellitic anhydride: 3.1 mol
PO-BPA: 7.2 mol
・ EO-BPA: 3.0 mol
The above polyester monomer is charged into an autoclave together with an esterification catalyst, and a polycondensation reaction is performed while heating to 210 ° C. in a nitrogen gas atmosphere with a decompression device, a water separation device, a nitrogen gas introduction device, a temperature measurement device and a stirring device A polyester resin was obtained.

(2) Production of hybrid resin component 80 parts by mass of the above polyester resin was dissolved and swollen in 100 parts by mass of xylene. Next, styrene, 15 parts by mass, 2-ethylhexyl acrylate, 5 parts by mass, dibutyltin oxide as an esterification catalyst 0.1 part by mass was added and heated to the reflux temperature of xylene to initiate a transesterification reaction between the carboxylic acid of the polyester resin and 2-ethylhexyl acrylate. Further, a xylene solution prepared by dissolving 1 part by mass of t-butyl hydroperoxide in 30 parts by mass of xylene as a radical polymerization initiator was dropped over about 1 hour. By maintaining at that temperature for 6 hours to complete the radical polymerization reaction and heating to 210 ° C. under reduced pressure to remove the solvent, the hydroxyl group of the polyester resin and 2-ethylhexyl acrylate, which is a copolymerization monomer of the vinyl polymer unit, The polyester resin, the vinyl polymer, and the hybrid resin 1 produced by the ester bond between the polyester unit and the vinyl polymer unit were obtained. Hybrid resin 1 has an acid value of 28 mgKOH / g, Tg of 59 ° C., peak molecular weight of 7300, weight average molecular weight (Mw) of 43,000, Mw / Mn of 8.5, and THF insoluble content of about 13% by mass. The content was.

(Resin Production Example 2)
(Polyester resin)
・ Terephthalic acid 10mol%
・ Fumaric acid 25mol%
・ Trimellitic anhydride 5 mol%
・ PO-BPO 35mol%
・ EO-BPA 25mol%
The above polyester monomer is charged into an autoclave together with an esterification catalyst, and a polycondensation reaction is performed while heating to 230 ° C. in a nitrogen gas atmosphere with a decompression device, a water separation device, a nitrogen gas introduction device, a temperature measurement device, and a stirring device. , Mn is 2,500, Mw is 10,000, Tg is 57 ° C., THF-insoluble content is 0%, acid value is 28, and hydroxyl value is 40. Resin A was obtained.

next,
・ Fumaric acid 32mol%
・ Trimellitic anhydride 10mol%
・ PO-BPO 35mol%
・ EO-BPA 23mol%

  These were similarly subjected to a condensation polymerization reaction, and 2 mol% of trimellitic anhydride was further added during the polymerization, Mn was 3,500, Mw was 150,000, Tg was 63 ° C., and THF insoluble. A second polyester resin B having a content of 28% by mass, an acid value of 25, and a hydroxyl value of 32 was obtained.

  The obtained polyester resins A and B were mixed with a Henschel mixer in units of 50 parts by mass, Mn was 2,800, Mw was 82,000, Tg was 60 ° C., THF insoluble content was 14% by mass, A polyester resin 2 having an acid value of 26 and a hydroxyl value of 36 was obtained.

(Production Example 3 of Resin)
(Styrene-acrylic resin)
-Styrene 70 parts by mass-N-butyl acrylate 24 parts by mass-Monobutyl maleate 6 parts by mass-G-tert-butyl peroxide 1 part by mass While stirring the above components in 200 parts by mass of xylene in a four-necked flask The inside of the container was sufficiently replaced with nitrogen, and the temperature was raised to 120 ° C., followed by dropwise addition over 3.5 hours. Further, the polymerization was completed after refluxing xylene, and the solvent was distilled off under reduced pressure to obtain styrene-acrylic resin 3. The obtained styrene-acrylic resin had an acid value of 28 mgKOH / g, Tg of 58 ° C., a peak molecular weight of 13,000, a weight average molecular weight (Mw) of 77,000, and Mw / Mn of 12.0.

[Production example of magnetic toner]
(Toner Production Example 1)
-Hybrid resin 1 100 parts by mass-Low molecular weight ethylene-propylene copolymer 8 parts by mass-Charge control agent S1 2 parts by mass-Magnetic iron oxide 90 parts by mass (average particle size 0.18 µm, coercive force 10.7 KA / m , Remanent magnetization 11.2 Am ² / kg, saturation magnetization 81.5 Am ² / kg)
The above mixture was melt-kneaded with a twin-screw kneader heated to 130 ° C., and the cooled mixture was coarsely pulverized with a hammer mill. Further, in the pulverization step, a mechanical pulverizer (Turbo Kogyo Co., Ltd.) turbo mill T-250 type shown in FIG. 1 is used, the gap between the rotor 314 and the stator 310 shown in FIG. The operation was performed at a peripheral speed of 115 m / s, a conveying air flow rate of 30 m ³ / h, and a crushed product supply rate of 23 kg / h.

  The obtained finely pulverized product was classified with an air classifier to obtain a magnetic toner in which particles having a weight average diameter of 7.7 μm and 10.1 μm or more were 6.6% by volume.

With respect to 100 parts by mass of the magnetic toner, 1.0 part by mass of hydrophobic dry silica (BET specific surface area: 300 m ² / g) is used with a Henschel mixer FM500 (manufactured by Mitsui Miike) for 4 minutes at a stirring blade rotational speed of 1100 rpm. The magnetic toner (1) of the present invention was obtained by rotation and external addition. Table 2 shows the physical properties of the magnetic toner (1) obtained.

(Toner Production Examples 2 to 15)
As shown in Table 2, magnetic toners (2) to (15) were obtained in the same manner as in Toner Production Example 1 except that the resin component and the charge control agent were changed and the pulverization conditions were changed. In Production Examples 13 and 14, a magnetic toner was produced using a collision-type airflow crusher shown in FIG. Table 2 shows the physical properties of the obtained magnetic toner.

[Example 1]
The following evaluation was performed using the magnetic toner (1). The evaluation results are shown in Table 3.

<Image evaluation test>
The developing device shown in FIG. 1 is set as shown in Table 2, and a commercially available copying machine IRC-3200 (manufactured by Canon Inc.) can be equipped with the developing device of the present invention, and magnetic one-component development can be performed. With modification, under a high temperature and high humidity environment (30 ° C / 80% RH), a test chart with a printing ratio of 6% was used to make 100,000 copies, and image density, fog, in-plane uniformity, The dot reproducibility and sleeve contamination were evaluated.

1) Image Density With a “Macbeth reflection densitometer” (manufactured by Macbeth Co., Ltd.), an SPI filter was used to measure the reflection density of an image having a 5 mm diameter circle, and the average value was evaluated.
Rank 5: Reflection density 1.45 or higher Rank 4: Reflection density 1.40 to 1.44
Rank 3: reflection density 1.35 to 1.39
Rank 2: Reflection density 1.30 to 1.34
Rank 1: Reflection density less than 1.29

2) In-plane density uniformity The “Macbeth reflection densitometer” (manufactured by Macbeth Co., Ltd.) measures the reflection density of a halftone image using an SPI filter. The reflection density has a maximum value Dmax and a minimum value ( The in-plane density uniformity was evaluated by the difference (Dmax−Dmin) of Dmin).
Rank 5: In-plane density uniformity Less than 0.1 Rank 4: In-plane density uniformity 0.1-0.19
Rank 3: In-plane density uniformity 0.2 to 0.29
Rank 2: In-plane density uniformity 0.30 to 0.39
Rank 1: In-plane density uniformity 0.40 or more

3) Fog Using a reflection densitometer (reflectometer model TC-6DS manufactured by Tokyo Denshoku), the reflection density (Dr) of the transfer paper before image formation and the reflection density after copying the solid white image The worst value was measured as (Ds), and the difference (Ds−Dr) was evaluated as a capri value.
Rank 5: Fog less than 0.1% Rank 4: Fog 0.1 to 0.5%
Rank 3: fog 0.6-1.0%
Rank 2: fog 1.1-2.0%
Rank 1: fog 2.0% or more

4) Dot reproducibility evaluation As shown in FIG. 9, a checkered pattern latent image composed of 1 dot, 2 dots, 3 dots, and 4 dots was used as a measurement sample. This sample is observed with a magnifying glass, and the dot reproducibility is determined by the number of dots of an image that can clearly check a checkered pattern. Smaller numbers indicate better dot reproducibility.
Rank 5: The image is faithful to the original.
Rank 4: When the image is enlarged with a magnifying glass, some scattering is observed. Rank 3: When the image is enlarged with a magnifying glass, scattering and disturbance are observed. Rank 2: When the image is visually observed, scattering and image distortion are observed. It has not been reproduced.

5) Fixing test of toner on sleeve After copying 100,000 sheets in a high temperature and high humidity environment (40 ° C / 90% RH), halftone image, toner coat on developing sleeve and developing sleeve with Sylbon paper The surface of the sleeve was visually observed and evaluated.
Rank 5: There is no toner deposit on the sleeve surface and no contamination occurs.
Rank 4: Toner deposits are slightly present on the surface of the sleeve end.
Rank 3: Toner deposits are slightly present on the sleeve surface, but the toner coat properties are not disturbed.
Rank 2: Toner adherence exists on the sleeve surface and disturbs the toner coat, but does not affect the image Rank 1: Toner adherence exists on the entire sleeve and disturbs the toner coat. It also has an adverse effect on images.

[Examples 2-16 and Comparative Examples 1-2]
Using the magnetic toners (2) to (15) obtained in the toner production examples 2 to 15 described above, as shown in Table 2, the configuration of the developing unit was changed, and the same procedure as in Example 1 was performed. An image evaluation test was conducted. The evaluation results are shown in Table 3.

[Comparative Example 3]
Using the magnetic toner (12) obtained in the toner production example 12 described above, the stirring / conveying member was changed to that shown in FIG. The image evaluation test was conducted in the same manner as in Example 1. The evaluation results are shown in Table 3.

[Comparative Example 4]
The developer shown in FIG. 10 is set as shown in Table 2, and a commercially available copying machine IRC-3200 (manufactured by Canon Inc.) can be equipped with this developer and modified so that magnetic one-component development can be performed. The above evaluation was performed in the same manner as in Comparative Example 1 except that it was added. The evaluation results are shown in Table 3.

FIG. 2 is a schematic cross-sectional view of an example mechanical pulverizer used in the toner pulverization step of the present invention. It is a schematic sectional drawing in the D-D 'surface in FIG. It is a perspective view of the rotor shown in FIG. It is a schematic sectional drawing of the conventional collision type airflow crusher. 1 is a schematic view illustrating an example of an image forming apparatus suitable for performing the developing method of the present invention. 1 is a schematic view illustrating an example of an image forming apparatus suitable for performing the developing method of the present invention. It is the schematic which shows an example of the stirring and conveyance member suitable for performing the image development method of this invention. It is the schematic which shows the comparative example of the stirring and conveyance member in the image development method of this invention. It is explanatory drawing of the checker pattern for testing the development characteristic in the image development method of this invention. It is the schematic which shows the comparative example of the image development method of this invention.

Explanation of symbols

212 Spiral chamber 219 Pipe 220 Distributor 222 Bag filter 224 Suction filter 229 Collection cyclone 301 Mechanical pulverizer 302 Powder discharge port 310 Stator 311 Powder input port 312 Rotating shaft 313 Casing 314 Rotor 315 First metering feeder 316 Jacket 317 Cooling water supply port 318 Cooling water discharge port 320 Rear chamber 321 Cold air generating means 331 Third constant supply machine Developer container 2. Development sleeve roller Fixed magnet roller 4. 4. Magnetic blade Stir paddle (stirring / conveying member)
6). Conveying screw 7,8. Elastic sheet (stirring blade)
9. Stirring shaft 10. Rib (elastic sheet reinforcement member)

Claims (5)

In a developing method in which magnetic toner is conveyed to a magnetic toner carrier by a stirring / conveying member, a thin layer is formed on the magnetic toner carrier by a regulating member, and a latent image on the latent image carrier is developed.
The stirring / conveying member is
1) A sheet-like rotating body having a certain width in the longitudinal direction of the developing container,
2) The rotation center axis is disposed below the lower end of the magnetic toner carrier containing the fixed magnet,
3) The magnetic toner in the developing container is supplied to the magnetic toner carrier, and the magnetic toner magnetically restrained in the vicinity of the magnetic toner carrier is stirred.
The magnetic toner has at least a binder resin, a magnetic material, and a charge control agent,
Of the magnetic toner particles having an equivalent circle diameter of 3 μm or more obtained by a flow type particle image measuring device, particles having a coarse particle ratio of 30% or more in the particle size distribution are cumulative values based on the number of particles having a circularity of 0.920 or more. And 60% by mass to 90% by mass. The magnetic toner has an average circularity a of particles having an equivalent circle diameter of 3 μm or more obtained by a flow type particle image measuring apparatus, and an average circle of particles having a coarse particle ratio of 30% or more in a particle size distribution of particles having an equivalent circle diameter of 3 μm or more. Degree b is
0.975 <b / a <1.010
The developing method according to claim 1, wherein: The shortest distance from the rotation center of the stirring / conveying member of the developing container to the surface of the magnetic toner carrier is La (mm), and the length from the rotation center of the stirring / conveying member to the end of the plate member is Lb (mm). )
0.1 <La-Lb <8.0
The developing method according to claim 1, wherein the developing method is satisfied. The stirring and conveying member and the magnetic toner carrier rotate in opposite directions, and the rotation number R1 (rpm) of the conveying member and the rotation number R2 (rpm) of the magnetic toner carrier are 2 × R1 <R2 <12 ×. R1
The developing method according to claim 1, wherein: The charge control agent is a resin obtained by polymerizing at least a monomer having a sulfonic acid group,
1) having a first acid value A and a second acid value B, measured by potentiometric titration,
2) The first acid value A is 2 (mgKOH / g) to 10 (mgKOH / g),
3) The first acid value A and the second acid value B are 1.20 ≦ B / A ≦ 2.00.
The developing method according to claim 1, wherein:

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