JPH0627741A - Toner for electrophotography - Google Patents

Abstract

PURPOSE:To enhance the electric charge stability against different charge amount, secular stability, humidity, and color material by allowing the resultant toner to contain at least one sort of phosphorus-containing compound as specified. CONSTITUTION:A toner concerned contains at least one sort of compound expressed as in the attached illustration, where R1, R2 may independently be any of the alkyl radical, substituent or unsubstituent benzyl radical, substituent or unsubstituent phenyl radical, and X represents hydrogen atom, halogen atom, or alkyl radical while A-represents an anion. Examples of A<-> are chlorine ion, bromine ion, iodine ion, sulfur tetrafluoro-borate, sulfate ion, alkyl sulfonic acid, and aryl sulfonic acid. The compound given by this expression works as a positive charge control agent and presents good compatibility with a binder resin and the resultant toner gives a high specific charge amount and good secular stability to ensure that a vivid image is produced stably even after the toner has been preserved for a long period of time, and a small quantity of its addition to the binder resin allows maintaining a high electric charging level.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a toner used for developing an electrostatic latent image in electrophotography, electrostatic recording and the like.

[0002]

2. Description of the Related Art Image forming processes such as electrostatic recording and electrostatic photography using static electricity are performed by using phthalocyanine pigment, selenium,
A process of forming an electrostatic latent image by an optical signal on a photoconductor obtained by applying a photoconductive substance such as cadmium sulfide or amorphous silicon onto a substrate such as aluminum or paper,
Colored fine particles of 5 to 50 μm, which is called toner, are contact-charged with a carrier (iron powder, ferrite powder, etc.) in the two-component developing method, and the toner is directly charged in the one-component developing method. After that, the electrostatic latent image is made to act and visualized. The toner needs to be provided with a charge corresponding to the polarity of the electrostatic latent image formed on the photoconductor, that is, either positive or negative charge.

Colored fine particles, generally called toner, contain a binder resin and a coloring material as essential components and, if necessary, are composed of magnetic powder or the like. As a method of imparting an electric charge to the toner, the charge characteristics of the binder resin itself can be used without using a charge control agent, but this does not provide good image quality due to poor stability over time and moisture resistance. Therefore, a charge control agent is usually added for the purpose of holding the charge of the toner and controlling the charge.

The quality characteristics required for the toner include excellent chargeability, fluidity, fixability, etc., but these quality characteristics are greatly affected by the charge control agent used in the toner.

As charge control agents conventionally added to toners, 1) 2: 1 type metal-containing complex salt dyes as colored negative charge control agents (eg, JP-B-45-26478, JP-B-41-201).
53) Phthalocyanine pigments (eg, JP-A-52-4593)
1) Further, as an example of a colorless negative charge control agent, a metal complex of an aromatic dicarboxylic acid (eg, JP-B-59-7384), a metal complex of salicylic acid (eg, JP-A-57-104940) or JP-A-61-41. Charge control agents and the like described in 3149 and the like,

2) As positive charge control agents, nigrosine dyes, triphenylmethane dyes, various quaternary ammonium salts (Journal of Japan Electrostatic Society 1980, Vol. 4, No. 3, P-144),
Organotin compounds such as dibutyltin oxide (eg, Japanese Patent Publication No. 57-29704) are known. Toners containing them as charge control agents are required to have good quality characteristics such as chargeability and stability over time. Does not fully satisfy.

For example, 2: 1 known as a negative charge control agent
Although the toner containing the metal-containing complex salt dye has a tentative level of high charge amount, the 2: 1 type metal-containing complex salt dye generally has a drawback that the dispersibility in the binder resin is poor. Therefore, the toner is not evenly distributed in the binder resin, the charge amount distribution of the obtained toner is extremely lacking in sharpness, and the obtained image has low gradation and poor image forming ability.

Further, the 2: 1 type metal-containing complex salt dye has a drawback that it can be used only for a toner having a limited hue centered on black, and when used as a color toner, the sharpness of the colorant is impaired. I will end up.

An example of a negatively charged negative charge control agent is a metal complex of an aromatic dicarboxylic acid (Japanese Patent Publication No. 59-59).
-7384) This compound has a difficulty in dispersibility, and as a colorless negative charge control agent having relatively good charging performance, a metal complex of salicylic acid can be mentioned (JP-A-57-57).
-104940) This contains heavy metals,
There is a problem in its safety. In addition, since the nigrosine dye and triphenylmethane dye known as positive charge control agents are themselves colored, they can be used only in toners with a limited hue centered on black. There is a drawback that the stability over time in continuous copying is not good. Further, the conventional quaternary ammonium salt has a drawback that it is inferior in stability over time due to insufficient moisture resistance when made into a toner, and does not give a good quality image upon repeated use.

[0010]

A charge control agent that is colorless and positively charged, is excellent in charge rise characteristics, charge amount and stability over time, and charge stability against differences in humidity and color materials.
An object of the present invention is to provide a safe charge control agent that has good compatibility with resins, exhibits stable properties during toner production, and does not contain heavy metals.

[0011]

The inventors of the present invention have made diligent efforts to solve the above-mentioned problems, and as a result, by incorporating at least one kind of a specific phosphorus-containing compound in the toner, the charging property of the toner is significantly increased. The present invention has been completed by finding out that it is improved.

That is, the present invention contains an electrophotographic toner containing at least one compound represented by the following formula (1).

[0013]

[Chemical 2]

(In the formula (1), R ₁ and R ₂ each independently represent an alkyl group, a substituted or unsubstituted benzyl group, a substituted or unsubstituted phenyl group, and X represents a hydrogen atom, a halogen or an alkyl group. And A ⁻ represents an anion).

The present invention will be described in detail. In the present invention, A ⁻ in the formula (1) represents an anion, and specific examples thereof include a chlorine ion, a bromine ion, an iodine ion, a tetrafluoroborate ion, a sulfate ion, an alkylsulfonic acid and an arylsulfonic acid. To be

The compound of the formula (1) acts as a positive charge control agent, but it has a good compatibility with the binder resin, and the toner containing it has a high specific charge amount and its stability over time. Since it is good, it gives a stable and clear image in the image formation of electrostatic recording even if the toner is stored for a long time, and maintains a high charge level even if a small amount is added to the binder resin. The amount to be added can be narrowed down much more than that. Further, since it has a colorless positive charging performance, it is possible to produce black toner and color toner. In addition, since this product does not contain heavy metals, it is highly safe for the environment. In addition, when the toner is prepared by the suspension polymerization method or the emulsion polymerization method, the heavy metal does not inhibit the polymerization as seen in the metal-containing charge control agent, so that the toner can be stably produced. . Specific examples of the formula (1) contained in the toner as the charge control agent in the present invention include, but are not limited to, the compounds represented by the following structural formulas.

In the following, the numbers in parentheses () in the respective formulas indicate specific example numbers.

[0018]

[Chemical 3]

[0019]

[Chemical 4]

[0020]

[Chemical 5]

[0021]

[Chemical 6]

[0022]

[Chemical 7]

[0023]

[Chemical 8]

[0024]

[Chemical 9]

[0025]

[Chemical 10]

[0026]

[Chemical 11]

[0027]

[Chemical 12]

[0028]

[Chemical 13]

[0029]

[Chemical 14]

[0030]

[Chemical 15]

[0031]

[Chemical 16]

[0032]

[Chemical 17]

[0033]

[Chemical 18]

[0034]

[Chemical 19]

As a method for producing a toner containing the compound of the formula (1), a mixture of the compound of the formula (1), a colorant and a binder resin can be heated and mixed by a heating kneader, a two-roll mill or the like. A method of kneading the binder resin in a molten state by a device, then cooling and solidifying it to a particle size of 3 to 20 μm by a crusher such as a jet mill or a ball mill, a colorant and a binder resin, and a compound of the formula (1) A method in which the compound is dissolved in a solvent (eg acetone, ethyl acetate), stirred, thrown into water for reprecipitation, filtered, dried, and then pulverized to a particle size of 3 to 20 μ by a pulverizer such as a ball mill, Formula (1)
The compound, the colorant, and the binder resin monomer are uniformly suspended in water, and the monomer is polymerized in the form of fine particles under stirring to form a precipitate, and the precipitate is filtered, washed with water, and dried. There is a method of obtaining a target product having a particle size of 3 to 20 μ by classifying it into a fine particle powder, and a soft particle upper core material (a core particle containing a low melting point resin for pressure fixing, a coloring component, a magnetic material, etc.). ) Can also be used as an outer shell material of a microcapsule toner having a form covered with a hard outer shell having a protective function and a charge control function. Furthermore, it is also possible to prepare colored fine particles containing no charge control agent by the above method, and then fix and add the compound of the formula (1) alone or together with an external additive such as colloidal silica to the particle surface by a mechanochemical method or the like. I can.

In these cases, the binder resin component is usually 9
9 to 65%, more preferably 98 to 85%, and the colorant is 1.
The charge control agent is used in a proportion of 0 to 15%, preferably 1.5 to 10%, and a charge control agent of 0.1 to 30%, more preferably 0.5 to 5% (both by weight). Examples of colorants that can be used in the electrophotographic toner of the present invention include carbon black, ultramarine blue, iron black, activated carbon, copper oxide, manganese dioxide, yellow lead, zinc yellow, cadmium yellow, yellow iron oxide, mineral fast yellow, Inorganic pigments such as nickel titanium yellow, red yellow lead, molybdenum orange, red iron oxide, cadmium red, manganese purple, titanium oxide, zinc sulfide, chrome green, chromium oxide and antimony white, CI. Pigment Yellow 1, CI. Pigment Red 9, C
I. Pigment Blue 15, Aniline Black, Naphthol Yellow S, Benzidine Yellow GR, Quinoline Yellow Lake, Anthrapyrimidine Yellow, Hansa Yellow G,
Permanent Yellow NCG, Pyrazolone Orange, Indanthrene Brilliant Orange GK, Pyrazolone Red, Brilliant Carmine 6B, Rhodamine Rake B,
Quinacridone, Alizarin Lake, Thioindigo Red, Thioindigo Maroon, Brilliant Carmine 3
B, methyl violet lake, dioxazine violet, aniline blue, metal-free phthalocyanine blue,
Phthalocyanine Blue, First Sky Blue, Indanthrene Blue BC, Phthalocyanine Green, Malachite Green Lake, Final Yellow Green G
Organic pigments such as CI. Solvent Yellow 93, CI.
Solven Yored 146, CI. Solvent Blue 3
5, CI. This Spurs Yellow 42, CI. This Spurs Red 59, CI. Disperse Blue 81, CI. Solvent Red 49, CI. Solvent Red 52, C
I. Solvent Red 109, CI. Basic Red 12, CI. Basic Red 1, CI. Direct Red 1, CI. Acid Red 1, CI. Basic Red 1, CI. Direct Red 4, CI. Mordant Red 30, CI. Direct Blue 2, CI. Acid Blue 9, CI. Basic Blue 3, CI. Basic Blue 5, CI. Acid Blue 15, CI. Conventionally known colorants such as oil-soluble dyes such as Modant Blue 7 (CI is an abbreviation for color index, the same applies hereinafter) can be mentioned.

As the binder resin, polystyrene, styrene-methacrylic acid copolymer, styrene-methacrylic acid ester copolymer, styrene-acrylic acid copolymer, styrene-acrylic acid ester copolymer, styrene-acrylonitrile copolymer are used. Polymers, acrylic resins, styrene-maleic acid copolymers, polyvinyl chloride, polyvinyl acetate, olefin resins, polyester resins, polyurethane resins, epoxy resins and the like can be used alone or in combination. Further, as the monomer of the binder resin, the monomer of the above resin is used, and specifically, styrene, α-
Vinyl aromatic hydrocarbon monomers such as methylstyrene, vinyltoluene, chlorostyrene, ethylstyrene, and divinylbenzene, acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, Monomers of acrylic compounds such as octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, phenyl methacrylate, acrylonitrile, methacrylonitrile, Monocarboxylic acids having a double bond such as acrylamide, maleic acid, methyl maleate,
Dicarboxylic acids such as butyl maleate, dimethyl maleate, phthalic acid, succinic acid, and terephthalic acid, ethylene, propylene, butylene, vinyl methyl ketone, vinyl hexyl ketone, vinyl methyl ether, vinyl isobutyl ether, and other vinyl monomers, Ethylene glycol, diethylene glycol, triethylene glycol,
1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,4-hexanediol, bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, and other polyol compounds, p-phenylene diisocyanate, Isocyanates such as p-xylylene diisocyanate, 1,4-tetramethylene diisocyanate, ethylamine,
Butylamine, ethylenediamine, 1,4-diaminobenzene, 1,4-diaminobutane, monoethanolamine, and other amines, diglycidyl ether, ethylene glycol diglycidyl ether, bisphenol A glycidyl ether, hydroquinone diglycidyl ether, and other epoxy compounds, etc. Alternatively, they can be mixed and used.

Further, the electrophotographic toner of the present invention requires a fluidizing agent such as silicon oxide, an antifoggant such as mineral oil, various magnetic substances for one-component system, and a conductivity-imparting agent such as zinc oxide. You may add according to it. The toner obtained in the present invention is, for example, iron powder of about 100-300 mesh or ferrite powder (carrier) coated with silicon or acrylic resin and 3-8: 97-92 (toner: carrier). It is used in a developing process in electrophotography by mixing in a weight ratio to form a developer.

The electrophotographic toner of the present invention has a sharp charge amount distribution and good stability over time as compared with the toner using a conventional charge control agent. As a result, an image with extremely high gradation is obtained, and the repetitive image forming ability is extremely good.

[0040]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In the examples, “parts” means “parts by weight” unless otherwise specified.

Example 1 Styrene-butyl acrylate copolymer (binder) 100 parts Low molecular weight polyethylene 3 parts Kayaset Yellow 963 (colorant) 1.2 parts Compound of the specific example (1) 1.5 parts A mixture of the above composition The mixture was melt-mixed (10 minutes) with a kneader adjusted to 130 to 140 ° C., then cooled and solidified. Next, after coarsely pulverizing with a coarse pulverizer, fine pulverization was performed with a jet mill pulverizer, and further classified with an air flow type classifier to obtain a toner having a particle size of 5 to 20 μm.

The toner thus obtained was mixed with an iron powder carrier of about 200 mesh at a weight ratio of 3:97 (toner: iron powder carrier) to obtain a developer A. Next, when the initial specific charge amount of the developer A was measured by a blow-off charge amount measuring device, it was +39.6 μC / g. Further, when copying was performed by a copying machine using this developer A, a clear yellow image excellent in gradation and not hindering the original hue of the colorant was obtained. Further, when a charge stability test (charge amount aging stability test and charge amount moisture resistance stability test) was carried out using the developer A, the results shown in Table 1 below were obtained.

Table 1 Charge amount aging stability test (unit: + μC / g) Time 5 minutes 15 minutes 30 minutes 1 hour 3 hours 6 hours Developer A 41.7 44.2 43.5 43.8 43.2 44.8 Charge amount moisture resistance stability test (unit, + μC / G) Initial charging After humidity resistance test Attenuation rate (%) 41.7 41.5 0.5

As shown in the above results, the temporal stability of the developer A was extremely excellent.

The charge stability test was carried out by the following method. Charge amount stability test with time A developer (a mixture of toner and iron powder or a silicon-coated ferrite carrier) is weighed in a poly container and contact-charged by a ball mill at 100 rpm for 6 hours. The charge amount of the toner was measured by the blow-off method.

Charge amount moisture resistance stability test Similar to the above charge amount aging stability test, the developer was weighed in a poly container, the container was opened and left at 34 ° C. and 86% RH for 2 days, and 100 rpm. After contact charging with the ball mill for 5 minutes, the charge amount of the toner was measured by the blow-off method.

Example 2 Polyester resin 100 parts Carbon black 6.0 parts Compound of the specific example (3) 1.5 parts

The mixture having the above composition was melt-mixed (10 minutes) with a kneader adjusted to 150 to 180 ° C.,
It was cooled and solidified. Then after coarse crushing with a coarse crusher,
It was finely pulverized by a jet mill pulverizer and further classified by an air stream classifier to obtain a toner having a particle size of 5-20 μm.

The toner thus obtained was mixed with an iron powder carrier of about 200 mesh in a weight ratio of 3:97 (toner: iron powder carrier) to obtain a developer B. Next, when the initial specific charge amount of the developer B was measured by a blow-off charge amount measuring device, it was +38.9 μC / g. Further, when a copy was made using this developer B with a copying machine, a black image excellent in gradation was obtained. Further, a charge stability test (charge amount temporal stability test, charge amount moisture resistance stability test) was performed using developer B in the same manner as in Example 1, and the results shown in Table 2 below were obtained.

Table 2 Charge amount aging stability test (unit, + μC / g) Time 5 minutes 15 minutes 30 minutes 1 hour 3 hours 6 hours Developer B 38.9 39.3 39.0 40.8 39.2 40.5 Charge amount moisture resistance stability test (unit, + μC / G) Initial charging After moisture resistance test Attenuation rate (%) 38.9 39.1 -0.5

As can be seen from the above results, the temporal stability and humidity stability of the developer B were extremely excellent.

Example 3 Styrene-acrylic acid methyl ester copolymer 100 parts Low molecular weight polypropylene 3 parts CI. Solvent Blue 111 1.5 parts Specific example (5) compound 1.5 parts

The mixture having the above composition was dissolved in 1000 parts of a mixed solvent of acetone and ethyl acetate (volume ratio 8: 2), and stirred at room temperature for 1 hour. Then, this mixture was dropped into 10000 parts of water with stirring to cause precipitation.
The formed precipitate was filtered and dried to obtain a coarse particle toner. Then, fine pulverization was carried out with a jet mill pulverizer, and further classification was carried out with a gas stream type classifier to obtain a toner of 5 to 20 μm.

The toner thus obtained was mixed with an iron powder carrier of about 200 mesh in a weight ratio of 3:97 (toner: iron powder carrier) to obtain a developer C. Then, the initial specific charge amount of the developer C was measured by a blow-off charge amount measuring device and found to be +39.6 μC / g. Further, copying was carried out by a copying machine using this developer C, and a clear blue image excellent in gradation and not hindering the original hue of the colorant was obtained. Further, a charge stability test (charge amount with time stability test, charge amount humidity resistance stability test) was performed using Developer C in the same manner as in Example 1, and the results shown in Table 3 below were obtained.

Table 3 Charge amount aging stability test (unit, + μC / g) Time 5 minutes 15 minutes 30 minutes 1 hour 3 hours 6 hours Developer C 39.6 41.3 41.0 41.8 42.2 41.5 Charge amount moisture resistance stability test (unit, + μC / G) Initial charging After moisture resistance test Attenuation rate (%) 39.6 40.5 -2.3

As shown in the above results, the temporal stability and humidity resistance stability of the developer C were extremely excellent.

Example 4 Epoxy resin 100 parts CI. Disperse Red 60 1.2 parts CI. Disperse Violet 17 0.3 parts Compound of specific example (6) 2.0 parts

The mixture having the above composition was melt-mixed in a kneader adjusted to 130 to 150 ° C., then naturally cooled and solidified. Then, finely pulverize with a coarse pulverizer and a jet mill pulverizer, and further classify with an airflow classifier to obtain a particle size of 5-
20 μ of toner was obtained.

0.3 part of colloidal silica was mixed with 100 parts of the obtained toner by a Henschel mixer. This was mixed with about 200 mesh iron powder carrier and 3:97.
(Toner: iron powder carrier) mixed in a weight ratio of developer D
Got Then, the initial specific charge amount of the developer D was measured by a blow-off charge amount measuring device to be +40.2 μC.
/ G. Further, when copying was performed by a copying machine using this developer D, a clear red image excellent in gradation and not hindering the original hue of the colorant was obtained.
Further, a charge stability test (charge amount aging test, charge amount moisture resistance stability test) was performed using Developer D in the same manner as in Example 1, and the results shown in Table 4 below were obtained.

Table 4 Charge amount aging stability test (unit, + μC / g) Time 5 minutes 15 minutes 30 minutes 1 hour 3 hours 6 hours Developer D 40.2 41.9 42.0 42.8 42.2 41.2 Charge amount moisture resistance stability test (unit, + μC / G) Initial charging After humidity resistance test Attenuation rate (%) 40.2 39.8 1.0

As shown in the above results, the temporal stability of the developer D was extremely excellent.

Example 5 Styrene-butyl acrylate copolymer 100 parts CI. Disperse Red 60 1.2 parts Specific example (12) compound 2.0 parts

The mixture having the above composition was melt-mixed in a kneader adjusted to 130 to 150 ° C., then naturally cooled and solidified. Then, finely pulverize with a coarse pulverizer and a jet mill pulverizer, and further classify with an airflow classifier to obtain a particle size of 5-
20 μ of toner was obtained.

0.3 part of colloidal silica was mixed with 100 parts of the obtained toner by a Henschel mixer. This was mixed with a silicon-coated ferrite carrier of about 125 mesh at a weight ratio of 3:97 (toner: ferrite carrier) to obtain a developer E. Then, the initial specific charge amount of the developer E was measured by a blow-off charge amount measuring device and found to be +37.2 μC / g. Further, copying was carried out by a copying machine using the developer E, and a clear red image excellent in gradation and not hindering the original hue of the colorant was obtained. Further, a charge stability test (charge amount aging test, charge amount moisture resistance stability test) was performed using the developer E in the same manner as in Example 1, and the results shown in Table 5 below were obtained.

Table 5 Stability test of charge amount (unit: + μC / g) Time 5 minutes 15 minutes 30 minutes 1 hour 3 hours 6 hours Developer E 37.2 38.9 38.0 38.8 39.2 39.2 Charge amount moisture resistance stability test (unit, + μC / G) Initial charging After moisture resistance test Attenuation rate (%) 37.2 38.4 -3.2

As shown in the above results, the temporal stability of the developer E was extremely excellent.

Example 6 Methyl styrene monomer 75 parts Ethyl acrylate monomer 20 parts Kayase Blue 814 1.8 parts Benzoyl peroxide 6 parts 2 parts of the compound of the specific example (16)

The mixture having the above composition was mixed with a homomixer 5
Stir and mix for a minute to give a homogeneous liquid that is water: 120
Parts / magnesium carbonate: added to 2.3 parts of the dispersion liquid and stirred with a homomixer at 6500 rpm for 5 minutes to obtain a uniform suspension. This suspension was placed in a 300 ml three-necked flask and the polymerization reaction was carried out at 70 ° C. for 5 hours with stirring at 200 rpm. After cooling to 40 ° C., 90 parts of a 5% dilute hydrochloric acid aqueous solution was added, and the mixture was filtered and washed with water and then heated to 40 ° C. And dry to a particle size of 5-2
0 μm of toner was obtained.

0.3 part of colloidal silica was mixed with 100 parts of the obtained toner by a Henschel mixer. This was mixed with about 200 mesh iron powder carrier and 3:97.
(Toner: iron powder carrier) mixed in a weight ratio of developer G
Got Then, the initial specific charge amount of this developer G was measured by a blow-off charge amount measuring device to be +38.2 μC.
/ G. Further, when copying was performed by a copying machine using this developer G, a clear blue image excellent in gradation and not hindering the original hue of the colorant was obtained.
In addition, when the charge stability test (charge amount temporal stability test, charge amount moisture resistance stability test) was carried out in the same manner as in Example 1 using the developer F, the results shown in Table 6 below were obtained.

Table 6 Charge amount aging stability test (unit, + μC / g) Time 5 minutes 15 minutes 30 minutes 1 hour 3 hours 6 hours Developer F 38.2 39.9 40.0 39.8 39.2 39.9 Charge amount moisture resistance stability test (unit, + μC / G) Initial charging After moisture resistance test Attenuation rate (%) 38.2 36.9 3.4

(Note) Colorant CI. : Color Index, Sol: Solve
nt, Dis: Disperse, Pig: Pigme
nt, B: Blue, R: Red, Y: Yellow,
Kayaset is a trade name of Nippon Kayaku Co., Ltd., an organic pigment

[0072]

The electrophotographic toner of the present invention has a sharp charge amount distribution, a high specific charge amount, moisture resistance and stability over time, as compared with conventional toners. As a result, an image with extremely high gradation is obtained, and the repetitive image forming ability is extremely good. In addition, since the charge control agent itself is colorless and does not contain heavy metals, etc., it is possible to select any colorant according to the hue required for color toner, and it is also highly safe for the environment. Is.

Claims (1)

[Claims] 1. An electrophotographic toner comprising at least one compound represented by the following formula (1): (In the formula (1), R ₁ and R ₂ each independently represent an alkyl group, a substituted or unsubstituted benzyl group or a substituted or unsubstituted phenyl group, and X represents a hydrogen atom, a halogen atom or an alkyl group, a ^- represents an anion).