JP2001253718A - Method for producing electrostatic charge controlling agent-containing ferrite particle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the lowering of the image density and resolution of a toner and fogging and to enhance transfer efficiency. SOLUTION: An iron-containing salt, a solvent and an alkali metal hydroxide are mixed and oxidized to obtain a reacted mixture containing a ferrite and a by-product. The ferrite is extracted from the mixture, a metallic salt- containing aqueous solution and an ion-containing aqueous solution of a carboxy compound are added to the ferrite and the resulting electrostatic charge controlling agent-containing ferrite is purified. A high purity ferrite 2 is contained in the obtained electrostatic charge controlling agent-containing ferrite particles 1 and the electrostatic charge controlling agent 3 is uniformly dispersed in a toner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing ferrite particles containing a charge controlling agent, which prevents a decrease in image density and resolution of electrophotographic copying and prevents fogging and enhances transfer efficiency.

[0002]

2. Description of the Related Art At present, electrophotographic copying machines, which are becoming smaller and faster, can withstand continuous operation for a long time even in a severe environment of high temperature and high humidity, and always copy stable and clear images of high quality. Is required. Therefore, there is a need for an electrophotographic toner that has excellent environmental stability, durability stability, and appropriate density, has no black spot fog, and can copy an image with high resolution.

In a conventional method for producing an electrophotographic toner by preliminary dry mixing, a resin, a coloring agent such as magnetite or carbon black, a charge controlling agent such as a gold-containing dye, a wax, etc. are put into a mixer such as a Henschel mixer at a time. While cooling, the shape of the rotating blades, the number of rotations, the number of rotations, and the like are changed to mix. However, resins, coloring agents such as magnetite or carbon black, charge control agents such as gold-containing dyes, and waxes have different particle diameters, specific gravities, and charging characteristics.
It is difficult to uniformly disperse these components. In particular, since it is difficult to uniformly disperse a colorant such as magnetite or carbon black and a charge controlling agent such as a gold-containing dye, image density and resolution are reduced, and fogging is generated, and transfer efficiency tends to be reduced.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a ferrite particle containing a charge controlling agent, which prevents a decrease in image density and resolution, and prevents fogging from occurring, and improves transfer efficiency, and a method for producing the same.

[0005]

According to the present invention, there is provided a method for producing a ferrite particle containing a charge controlling agent, the method comprising the steps of:
Mixing a hydroxide of an alkali metal to oxidize iron in the salt to obtain a reaction mixture containing ferrite and by-products; and dissolving and removing by-products in the reaction mixture in a solvent to remove ferrite. Extracting, adding a metal salt-containing aqueous solution containing a metal salt, a solvent and an alkali metal hydroxide to the ferrite, before or after adding the metal salt-containing aqueous solution to the ferrite, a carboxyl compound, water Adding an ion-containing aqueous solution of a carboxyl compound containing an alkali metal hydroxide to ferrite, and purifying a ferrite containing a charge control agent obtained by mixing the ferrite, an aqueous solution containing a metal salt, and an aqueous solution containing an ion. And a step of performing.

[0006] Oxidation of iron contained in the salt produces a reaction mixture containing ferrites such as magnetite and by-products such as sulfate, and after removing the by-products, produces charge control agent-containing ferrite particles. As a result, high-purity ferrite particles are obtained, and a small amount of ferrite sufficiently exerts a function as a colorant. Ferrite transports toner particles such as binder resin to a magnetic roll as a carrier.If the ferrite particles are of high purity, the toner particles adhere to the ferrite particles reliably and uniformly, and together with the ferrite particles, The particles are well transported to the magnetic roll. Furthermore, since the ferrite is mixed at the stage of generating the charge control agent instead of mixing the charge control agent and the ferrite after generation, the charge control agent and the ferrite particles are uniformly dispersed in the toner particles, and the charge control is performed. The agents do not agglomerate with each other and uneven charging does not occur.

[0007] Further, a step of mixing a cation compound with an aqueous solution of the extracted ferrite to obtain an ionic ferrite aqueous solution, and mixing a charge control agent solution obtained by dissolving a charge control agent in an aqueous solvent and an ionic ferrite aqueous solution. The method includes a step of obtaining a charge control agent-containing ferrite, and a step of filtering, washing, drying, and pulverizing the obtained charge control agent-containing ferrite.

The embodiment according to the present invention includes a step of uniformly mixing the ferrite and the charge control agent and forming particles having an average particle diameter of 1.0 μm or less in which the ferrite and the charge control agent are integrally attached. The charge control agent of the charge control agent-containing ferrite is n [R-COO] ^-. [M] ^{n +} (I) n [R-COO] ^-. [ _CM ] ^{n +} (II) (M is metal, _CM is A metal complex, R is an aryl group or an alkyl group, and n is an integer of 1 to 8) a salt of a metal ion represented by the formula (I) and an ion of a carboxyl compound;
It is formed by a salt of a mixture of a plurality of metal complex ions shown in I) and a carboxyl compound ion. The solvent is water or a mixture of water and alcohol.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for producing a charge control agent-containing ferrite particle according to the present invention will be described below.

In the production method according to the present invention, first, a salt containing iron, a solvent, and a hydroxide of an alkali metal are mixed, and the iron in the salt is oxidized by aeration to obtain ferrite (MO.Fe).
A reaction mixture comprising ₂ O ₃ ) and by-products is produced. Oxidation is performed at a temperature of 70-90 ° C for 2-5 hours. The solvent is water or a mixture of water and an alcohol, and the alcohol is selected from methyl alcohol, ethyl alcohol, butyl alcohol, propyl alcohol, isopropyl alcohol and the like. Since the reaction mixture contains by-products other than ferrite, the by-products are dissolved in a solvent and removed. This is repeated several times to extract ferrite with high purity.

Next, an aqueous solution containing a metal salt containing a metal salt, a solvent which is water or a mixture of water and an alcohol, and a hydroxide of an alkali metal is added to the ferrite. An ion-containing aqueous solution of a carboxyl compound containing a metal hydroxide is added to the ferrite and reacted for 1 to 2 hours. Before adding the metal salt-containing aqueous solution to the ferrite, the ion-containing aqueous solution may be added to the ferrite. In water, metal salts and alkali metal hydroxides form many types of metal complex ions.However, when alcohol is used as a solvent in addition to water, different types of metal complex ions are used when only water is used as a solvent. It is formed, the viscosity is reduced and the reaction is carried out quickly.

The metal of the metal salt is iron, chromium, nickel,
One or more selected from cobalt, tin, manganese, cerium, silver, zinc, magnesium, zirconium, beryllium, copper, aluminum, barium, calcium, titanium, indium, lithium and cadmium. Carboxyl compounds are salicylic acid, derivatives of salicylic acid, naphthoic acid and naphthoic acid derivatives,
The derivative of salicylic acid is selected from 3,5-di-tert-butylsalicylic acid and 5- (5-t-octyl) salicylic acid, and the naphthoic acid derivative is 2-hydroxy-3-
Naphthoic acid, alkyl (C4-9) -2-hydroxy-3-naphthoic acid, 5,6,7,8-tetrahydro-2-
Hydroxy-3-naphthoic acid, alkyl (C4-9)
-5,6,7,8-tetrahydro-2-hydroxy-3-
Naphthoic acid, 1-hydroxy-2-naphthoic acid, alkyl (4-9 carbon atoms) -1-hydroxy-2-naphthoic acid,
It is selected from 5,6,7,8-tetrahydro-1-hydroxy-2-naphthoic acid and the like.

[0013] Finally, the ferrite containing the charge control agent obtained by mixing the ferrite, the metal salt-containing aqueous solution and the ion-containing aqueous solution is filtered, washed, dried and pulverized. As a result, as shown in FIG. 1, the ferrite (2) and the charge control agent
(3) is uniformly mixed with ferrite (2) and a charge control agent.
Thus, ferrite particles (1) containing a charge controlling agent and having an average particle diameter of 1.0 μm or less, which are integrally adhered to (3), are obtained. The average particle size is 1.
0 μm or less, preferably 0.01 μm or more. It is difficult to uniformly pulverize particles less than 0.01 μm to produce,
Variations in the particle size increase and there are manufacturing disadvantages.

The charge control agent of the charge control agent-containing ferrite and the purified charge control agent-containing ferrite particles (1) is n [R-COO] ^-. [M] ^{n +} (I) n [R-COO] ^-. [C _M ] ^{n +} (II) (M is a metal, C _M is a metal complex, R is an aryl group or an alkyl group, n is an integer of 1 to 8) The metal ion represented by the formula (I) and the ion of a carboxyl compound And a salt of the formula (I
It includes a salt of a mixture of a plurality of metal complex ions shown in I) and a carboxyl compound ion. Since it contains a mixture of metal ions and a plurality of metal complex ions, it has good compatibility with the binder resin and has the effect of stabilizing the potential on the toner surface. In addition, the toner has excellent charge stability to a two-component developer carrier, and has excellent frictional chargeability and stability between toner particles and between a one-component toner and a toner carrier such as a sleeve. No stain and poor fixing occur. The content of the charge control agent (3) with respect to the ferrite (2) is 0.1 to 10% by weight, preferably 0.5 to 3% by weight. When the content of the charge control agent (3) is less than 0.1% by weight, the charge amount is low and the chargeability is not stable. If it exceeds 10% by weight, the charge amount becomes too high, and the ratio of ferrite (2) acting as a colorant decreases, so that the toner concentration decreases.

[0015] The metal complex ion is selected from the group consisting of basic chromium hydroxide ion, basic chromium chloride ion, basic zinc chloride ion and basic chromium sulfate ion;
Specific examples are illustrated by the following chemical formulas.

Basic chromium hydroxide ion: [Cr (H ₂ O)
₄ (OH) ₂ ] ⁺ ; [Cr (OH)] ²⁺ ; [Cr (H ₂ O) ₅ OH] ²⁺ ;
[(H ₂ O) ₄ CrO ₂ Cr (H ₂ O) ₄ ] ²⁺ ; [(H ₂ O) ₆ C
r] ³⁺ ; [(H ₂ O) ₄ Cr (OH) ₂ Cr (H ₂ O) ₄ ] ⁴⁺ ; [(H ₂
O) ₄ Cr (OH) ₂ (H ₂ O) Cr (H ₂ O) ₄ ] ⁴⁺ ; [Cr ₄ (O
H) ₈ ] ⁴⁺ ; [Cr ₃ (OH) ₄ (H ₂ O) ₁₀ ] ⁵⁺ ;

[0017]

Embedded image ;

[0018]

Embedded image ;

[0019]

Embedded image ;

Basic chromium chloride ion: [(H_TwoO)_FiveCr
Cl_Two]⁺; [(H_TwoO) CrCl_Five]⁺; [(H_TwoO)_FourCrC
l_Two]⁺; [(H_TwoO)_FiveCrCl]²⁺; [(H_TwoO)_ThreeCrC
l]²⁺; [(H_TwoO) _TwoCrCl_ThreeIs derived when dissolved in water
Metal complex ion; [Cr_Five(OH)₆Cl₉・ 12H_TwoO] is water
Metal complex ions derived when dissolved in

Basic zinc chloride ion: [ZnCl ₂ Zn
A metal complex ion derived when (OH) ₂ ] is dissolved in water;
Metal complex ion derived when [ZnCl ₂ 4Zn (OH) ₂ H ₂ O] is dissolved in water; [ZnCl ₂ 6Zn (OH) ₂ 2H
₂ O] is a metal complex ion derived when dissolved in water;

Basic chromium sulfate ion: [Cr (SO ₄ )
[(H ₂ O)] ⁺ ; [Cr ₅ (SO ₄ ) (H ₂ O) ₅ ] ⁺ ; [(H ₂ O) ₃ Cr
(OH) (SO ₄ ) ₂ Cr (H ₂ O) ₃ ] ⁺ ; [(H ₂ O) ₃ Cr (OH) ₂
(SO ₄ ) Cr (H ₂ O) ₃ ] ²⁺

[0023]

Embedded image

[(H ₂ O) ₃ Cr (OH) (SO ₄ ) ₂ Cr (H ₂ O)
₄ ] ³⁺ ; [(H ₂ O) ₄ Cr (OH) (SO ₄ ) Cr (H ₂ O) ₄ ] ³⁺ ;
[(H ₂ O) ₆ Cr ₂ (H ₂ O) ₆ ] ³⁺ ; [(H ₂ O) ₄ Cr (OH) ₂ C
r (H ₂ O) ₄ ] ⁴⁺ ; The purified charge control agent-containing ferrite particles (1) are thoroughly mixed with a binder resin, wax, and the like using a mixer such as a ball mill or a Henschel mixer, and then heated roll kneader. ,
The mixture is kneaded by a kneading machine such as an extruder, solidified by cooling, pulverized, classified and post-processed (externally added) to produce a toner.
In addition, it can be obtained by a spraying method, a polymerization method, or the like.

The content of the charge control agent-containing ferrite particles (1) with respect to the toner is 5 to 70% by weight, preferably 25 to 55% by weight. If it is less than 5% by weight, the magnetic force is weak, the toner cannot be carried on the magnetic roll,
%, The proportion of the binder resin component in the toner is small,
The fixability of the toner to the paper is deteriorated.

As the binder resin, polystyrene, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer,
Styrene resin such as styrene-acrylate copolymer, styrene-methacrylate copolymer, styrene-butadiene copolymer, saturated polyester resin, unsaturated polyester resin, epoxy resin, phenol resin,
It is selected from maleic acid resin, coumarone resin, chlorinated paraffin, xylene resin, vinyl chloride resin, polypropylene, polyethylene and the like.

The wax may be a low molecular weight polypropylene, a low molecular weight polyethylene, a microcrystalline wax,
It is selected from carnauba wax, sasol wax, paraffin wax, aliphatic solid alcohol and the like.

If necessary, a fluidizing agent, a charging aid, an abrasive, and the like can be added to the toner. Fine particles of silica, titanium oxide, alumina, etc., fine particles obtained by hydrophobizing them with silicon oil, silicon varnish, silane coupling agent, etc., inorganic oxides such as metal oxides such as calcium titanate, metal carbides and metal nitrides Examples include fine particles, organic fine particles such as methyl methacrylate, polyvinylidene fluoride, and polystyrene; and organic metal compound fine particles such as zinc stearate and calcium stearate.

On the other hand, an aqueous solution of a cation compound is mixed with the aqueous solution of the extracted ferrite to produce an aqueous solution of an ionic ferrite.
A charge control agent-containing ferrite may be produced by mixing a charge control agent solution in which a charge control agent is dissolved in an aqueous solvent.
By dissolving a positive ion compound in an aqueous ferrite solution and turning the surroundings of the ferrite into a positive ion, a negative charge control agent is attached to the ferrite. The positive ion compound is selected from amines such as butylamine, amylamine, octylamine, nonylamine, dimethylamine, dipropylamine, triethylamine, triallylamine, benzylamine, and triethanolamine. The aqueous solvent is selected from alcohols such as methyl alcohol, ethyl alcohol, butyl alcohol, propyl alcohol, and isopropyl alcohol.

The obtained charge control agent-containing ferrite is purified in the same manner as described above to obtain charge control agent-containing ferrite particles (1) having an average particle size of 1.0 μm or less as shown in FIG.

[0031]

EXAMPLES Examples of the method for producing the charge control agent-containing ferrite particles according to the present invention will be described below along with comparative examples. All parts are parts by weight.

Example 1 <Synthesis of Charge Control Agent-Containing Ferrite Particles> Ferrous Sulfate 3
A solution prepared by adding 000 parts to 4400 parts of water and dissolved and a solution prepared by adding 1000 parts of sodium hydroxide to 1500 parts of water and dissolved were mixed and stirred. Next, while blowing air, 9
Oxidation reaction was carried out at 0 ° C. for 5 hours.
O.Fe ₂ O ₃ ) particles were precipitated and the supernatant was discarded. To this, 3000 parts of water was added and stirred, and the decantation of precipitating the ferrite particles and discarding the supernatant liquid was repeated seven times, and sodium sulfate as a by-product was removed to extract high-purity ferrite particles. To an aqueous solution of the extracted ferrite particles, 110 parts of chromium sulfate was added and dissolved, and 10 parts of sodium hydroxide, 1690 parts of water, and 17 parts of methanol were added.
0 parts were added and stirred to dissolve. Further, at a temperature of 90 ° C., 10 parts of sodium hydroxide, 1330 parts of water,
An ion-containing aqueous solution of a carboxyl compound containing 70 parts of 3,5-ditert-butylsalicylic acid was added and reacted at 90 ° C. for 1 hour to obtain a charge control agent-containing ferrite. After the completion of the reaction, the mixture was filtered and washed with water, dried at 120 ° C. for 6 hours and pulverized to obtain chromium 3,5-di-tert-butylsalicylate having an average particle diameter of 0.6 μm, 3,5-di-tert-butylsalicylic acid and basic 840 parts of ferrite particles uniformly containing 0.8% of a charge control agent which is a mixture with a salt of a chromium sulfate complex were obtained.

<Manufacture of toner and confirmation of performance> Styrene-acrylate copolymer 49 parts Low molecular weight polypropylene NP-505 (manufactured by Mitsui Petrochemical Co., Ltd.) 3 parts Charge control agent-containing ferrite particles 48 parts After dry-mixing with a Henschel mixer, the mixture was kneaded with a twin-screw kneader whose temperature was set to 130 ° C. The obtained kneaded material was cooled, coarsely pulverized to about 2 mm or less by a hammer mill, finely pulverized by a jet pulverizer having a coarse powder classification function, and classified by a gas stream type classifier to obtain an average particle size of 9 μm.
Was obtained. To 100 parts of the obtained raw toner, 0.3 part of hydrophobic colloidal silica and 1.0 part of calcium titanate were added and mixed by a mixer (Henschel mixer).
Aggregates were removed by a vibration sieve to obtain a toner. The toner was subjected to a continuous copy test of 10,000 copies using a commercially available copying machine (trade name: NP-400RE, manufactured by Canon Inc.). As shown in Table 1, the image density and resolution did not decrease, and fogging did not occur. And the transfer efficiency was high.

[Comparative Example 1] <Production of toner and confirmation of performance> Styrene-acrylate copolymer 49 parts Low molecular weight polypropylene NP-505 (manufactured by Mitsui Petrochemical Co., Ltd.) 3 parts Ferrite (FeO.Fe ₂ O ₃ ) 44 parts of particles Charge control agent (chromium 3,5-ditert-butylsalicylate) 4 parts The above materials were dry-mixed by a mixer (Henschel mixer), and then kneaded by a twin-screw kneader set to a temperature of 130 ° C. The obtained kneaded material was cooled and coarsely pulverized to about 2 mm or less with a hammer mill, finely pulverized with a jet pulverizer having a coarse powder classification function, and classified with a gas stream type classifier to obtain an average particle size of 9.1 μm.
Was obtained. To 100 parts of the obtained raw toner, 0.3 part of hydrophobic colloidal silica and 1.0 part of calcium titanate were added and mixed by a mixer (Henschel mixer), and then aggregates were removed by a vibration sieve to obtain a toner. The toner was subjected to a continuous copy test of 10,000 copies using a commercially available copying machine (trade name: NP-400RE, manufactured by Canon).
As shown in (1), the image density and resolution were low, fogging occurred frequently, and the transfer efficiency was low.

Example 2 <Synthesis of Charge Control Agent-Containing Ferrite Particles> Zinc Chloride 80
And 2,200 parts of ferrous sulfate were added and dissolved in 8380 parts of water and 1100 parts of isopropyl alcohol, and a liquid in which 620 parts of sodium hydroxide was added and dissolved in 4880 parts of water was mixed and stirred. Next, an oxidation reaction was performed at 75 ° C. for 3 hours while blowing air into the obtained ferrite (Z
nO.Fe ₂ O ₃ ) particles were precipitated and the supernatant was discarded.
To this, 3000 parts of water was added and stirred, and the decantation of precipitating the ferrite particles and discarding the supernatant liquid was repeated seven times, thereby removing sodium sulfate as a by-product to extract high-purity ferrite particles. To the aqueous solution of the extracted ferrite particles was added 40 parts of triethanolamine, which is a positive ion compound, and the mixture was stirred for 10 minutes to obtain an ionic ferrite aqueous solution. Charge control, which is a mixture of zinc 2-hydroxy-3-naphthoate and iron 2-hydroxy-3-naphthoate, and salts of 2-hydroxy-3-naphthoic acid, a basic zinc chloride complex and a basic iron sulfate complex A solution prepared by dissolving 16.5 parts of the agent in 50 parts of ethanol was added to an aqueous ionic ferrite solution and stirred for 15 minutes to obtain a ferrite containing a charge control agent. Further, the mixture was filtered and washed with water, dried at 120 ° C. for 6 hours and pulverized, and zinc 2-hydroxy-3-naphthoate and iron 2-hydroxy-3-naphthoate having an average particle diameter of 0.3 μm,
Ferrite (ZnO.Fe) containing uniformly 2.2% of a charge control agent which is a mixture of 2-hydroxy-3-naphthoic acid, a salt of a basic zinc chloride complex and a salt of a basic iron sulfate complex
740 parts of ₂ O ₃ ) particles were obtained.

<Manufacture of toner and confirmation of performance> Saturated polyester resin 68 parts Low molecular weight polypropylene NP-505 (manufactured by Mitsui Petrochemical Co., Ltd.) 2 parts Charge control agent-containing ferrite particles 30 parts Drying of the above materials using a mixer (Henschel mixer) After mixing, the mixture was kneaded with a twin-screw kneader set at a temperature of 130 ° C. The obtained kneaded material was cooled, coarsely pulverized to about 2 mm or less by a hammer mill, finely pulverized by a jet pulverizer having a coarse powder classification function, and classified by a gas stream type classifier to obtain an average particle size of 8.8.
A μm raw toner was obtained. To 100 parts of the obtained raw toner, 0.3 part of hydrophobic colloidal silica and 0.5 part of methyl methacrylate microparticles were added and mixed by a mixer (Henschel mixer). Then, aggregates were removed by a vibration sieve to obtain a toner. Was. This toner was purchased from a commercially available copier (trade name NP-6).
As shown in Table 1, the image density and resolution did not decrease, fog did not occur, and the transfer efficiency was high.

Comparative Example 2 <Manufacture and Confirmation of Performance of Toner> Saturated polyester resin 68 parts Low molecular weight polypropylene NP-505 (manufactured by Mitsui Petrochemical Co.) 2 parts Ferrite (ZnO.Fe ₂ O ₃ ) particles 29.3 parts 0.7 parts of charge control agent (zinc 2-hydroxy-3-naphthoate) The above-mentioned materials were dry-mixed with a mixer (Henschel mixer), and then kneaded with a twin-screw kneader whose temperature was set to 130 ° C. The obtained kneaded material was cooled, coarsely pulverized to about 2 mm or less by a hammer mill, finely pulverized by a jet pulverizer having a coarse powder classification function, and classified by a gas stream type classifier to obtain an average particle size of 9 μm.
Was obtained. To 100 parts of the obtained raw toner, 0.3 part of hydrophobic colloidal silica and 0.5 part of methyl methacrylate microparticles were added and mixed by a mixer (Henschel mixer). Then, aggregates were removed by a vibration sieve to obtain a toner. Was. This toner was purchased from a commercially available copier (trade name: NP-606).
As shown in Table 1, image density and resolution were low, fogging occurred frequently, and transfer efficiency was low, as shown in Table 1.

Table 1 shows the results of evaluating the copy image at the start of the continuous copy test and the copy image at the end of each item for each Example and Comparative Example. The electrophotographic society test chart No. 1-R was used as a copy sample. The image density was determined by measuring the density of the solid black portion of the copied image with a Macbeth densitometer. The resolution was evaluated by visually observing the copied image using a loupe and counting the number of independent fine lines. For fog, the density of a non-image portion of a copied image was measured with a Macbeth densitometer. The transfer efficiency is a value obtained by subtracting a value obtained by dividing the amount of waste toner (increase in waste toner portion) by the amount of used toner (increase in waste toner portion) by 100 and multiplying by 100.

[0039]

[Table 1]

[0040]

According to the method for producing ferrite particles containing a charge controlling agent according to the present invention, it is possible to prevent a decrease in the image density and resolution of the toner and to prevent the occurrence of fogging and to increase the transfer efficiency.

[Brief description of the drawings]

FIG. 1 is an enlarged view of a ferrite particle containing a charge control agent according to the present invention.

[Explanation of symbols]

(1) Ferrite particles containing charge control agent, (2) Ferrite, (3) Charge control agent,

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H005 BA02 BA03 CA25 CB04 DA01 4G002 AA04 AA07 AB02 AC00 AD00 AE01

Claims (5)

[Claims] A step of mixing a salt containing iron, a solvent, and a hydroxide of an alkali metal to oxidize iron in the salt to obtain a reaction mixture containing ferrite and by-products; Dissolving and removing by-products in a solvent to extract ferrite; adding a metal salt-containing aqueous solution containing a metal salt, a solvent, and an alkali metal hydroxide to the ferrite; Before or after adding the aqueous solution to the ferrite,
Adding an ion-containing aqueous solution of a carboxyl compound containing a carboxyl compound, water, and an alkali metal hydroxide to the ferrite; and a charge control agent obtained by mixing the ferrite, the metal salt-containing aqueous solution, and the ion-containing aqueous solution. And purifying the ferrite-containing ferrite particles. 2. A step of mixing a salt containing iron, a solvent, and a hydroxide of an alkali metal to oxidize iron in the salt to obtain a reaction mixture containing ferrite and by-products. Dissolving and removing by-products in a solvent to extract ferrite; mixing a positive ion compound with an aqueous solution of the extracted ferrite to obtain an ionic ferrite aqueous solution; dissolving a charge control agent in an aqueous solvent A charge control agent solution,
Mixing a ionic ferrite aqueous solution to obtain a charge control agent-containing ferrite; and filtering, washing, drying, and pulverizing the obtained charge control agent-containing ferrite. Recipe. 3. The method according to claim 1, further comprising the step of uniformly mixing the ferrite and the charge control agent and forming particles having an average particle diameter of 1.0 μm or less in which the ferrite and the charge control agent are integrally attached. Of ferrite particles containing a charge control agent. 4. The charge control agent of the charge control agent-containing ferrite is n [R-COO] ^-. [M] ^{n +} (I) n [R-COO] ^-. [ _CM ] ^{n +} (II) (M is A metal, C _M is a metal complex, R is an aryl group or an alkyl group, and n is an integer of 1 to 8.) A salt of a metal ion represented by the formula (I) and an ion of a carboxyl compound;
The method for producing a charge control agent-containing ferrite particle according to claim 1 or 2, which forms a salt of a mixture of a plurality of metal complex ions shown in I) and a carboxyl compound ion. 5. The method for producing a charge control agent-containing ferrite particle according to claim 1, wherein the solvent is water or a mixture of water and an alcohol.