JP2977142B2 - Electrophotographic toner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. 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 utilizing static electricity include phthalocyanine pigments, selenium,
A process of forming an electrostatic latent image by an optical signal on a photoreceptor obtained by applying a photoconductive substance such as cadmium sulfide, amorphous silicon or the like on a substrate such as aluminum or paper;
In the two-component developing method, the colored fine particles adjusted to 5 to 50 μ called the toner are charged by contacting the toner with a carrier (iron powder, ferrite powder, etc.). In the one-component developing method, the toner is directly charged. After that, it is made to act on the electrostatic latent image to make it visible. Note that the toner needs to be provided with a charge corresponding to the polarity of the electrostatic latent image formed on the photoreceptor, that is, any of positive and negative charges.

[0003] Colored fine particles generally called toner contain a binder resin and a coloring material as essential components, and are further formed of magnetic powder or the like as required. As a method for imparting charge to the toner, the charge characteristics of the binder resin itself can be used without using a charge control agent. However, stability with time and moisture resistance are poor and good image quality cannot be obtained. Therefore, a charge control agent is usually added for the purpose of holding and controlling the charge of the toner. Quality characteristics required of the toner include excellent chargeability, fluidity, fixability, and the like. These quality characteristics are greatly affected by a charge control agent used in the toner.

The charge control agents conventionally added to toners include: 1) 2: 1 type metal-containing complex dyes as colored negative charge control agents (eg, JP-B-45-26478, JP-B-41-201)
531) Phthalocyanine pigment (for example, JP-A-52-459)
31) Also, examples of colorless negative charge control agents include a gold complex of an aromatic dicarboxylic acid (eg, Japanese Patent Publication No. 59-7384) and a metal complex of salicylic acid (eg, JP-A-57-104940).
Or 2) positive charge control agents such as nigrosine dyes, triphenylmethane dyes, and various quaternary ammonium salts (Electrostatics Society of Japan, 1980, vol. 4). No. 3, P-114) and organotin compounds such as dibutyltin oxide (eg, Japanese Patent Publication No. 57-297)
04) are known, but toners containing these as a charge control agent do not sufficiently satisfy the quality characteristics required for the toner, such as chargeability and stability over time.

For example, 2: 1 known as a negative charge control agent
Although the toner containing the metal-containing complex dye has a certain level of charge, the 2: 1 type metal-containing complex dye generally has a disadvantage that the dispersibility in the binder resin is poor. Therefore, the toner is not uniformly distributed in the binder resin, and the charge amount distribution of the obtained toner is extremely poor in sharpness. The obtained image has low gradation and poor image forming ability. Further, the 2: 1 type metal-containing complex salt dye has a disadvantage that it can be used only for a toner having a limited hue centering on black, and the use as a color toner impairs the sharpness of the colorant.

An example of a nearly colorless negative charge control agent is a metal complex of an aromatic dicarboxylic acid (Japanese Patent Publication No. 59-1984).
This product has a drawback that it cannot be completely colorless and has a disadvantage in its dispersibility. As a colorless negative charge control agent having relatively good charging performance, there is a metal complex of salicylic acid (JP-A-57-1049).
40) This contains heavy metals, and there is a problem in its safety. JP-A-61-3149 and JP-A-63-38958 are colorless negative charge control agents containing no heavy metals.
However, the compound is known to have a low melting point, so that it is difficult to produce a stable toner due to poor thermal stability at the time of toner production, and a low charge rising speed. There is a disadvantage that.

[0007] Nigrosine dyes and triphenylmethane dyes, which are known as positive charge control agents, are themselves colored and therefore can be used only in toners having a limited hue, mainly black. However, there is a disadvantage that the stability over time for continuous copying of toner is not good. Further, conventional quaternary ammonium salts have the disadvantage that when formed into toner, they have poor stability over time due to insufficient moisture resistance, and do not give high-quality images when used repeatedly. As described above, the known charge control agents do not sufficiently satisfy the quality characteristics required for the toner.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a colorless and positively charged charge control agent, which has good dispersibility in a binder resin, excellent charge start-up characteristics, excellent charging stability over time, temperature and humidity. Provide a charge control agent that has high charge controllability without being affected by changes in, and does not contain heavy metals, and furthermore has excellent charge rising stability and environmental resistance, and high gradation. It is to provide a toner which gives an image.

[0009]

Means for Solving the Problems The present inventors have made intensive efforts to solve the above-mentioned problems, and as a result, by including at least one compound of the following formula (1) in the toner, the charging characteristics of the toner have been improved. The present invention was found to be greatly improved, and the present invention was completed.

[0010]

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In the formula (1), R ₁ , R ₂ and R ₃
Represents an alkyl group having 4 to 8 carbon atoms, a substituted or unsubstituted aryl group, or a benzyl group; R ₄ represents an alkenyl group;
-Phenyl-2-propenyl group, alkynyl group, or 3
- phenyl-2-propynyl group, X ^- represents an anion. ]

The compound of the formula (1) acts as a charge control agent, but has good compatibility with the binder resin, and the toner containing the compound has a high specific charge amount and has good stability over time. Therefore, even when the toner is stored for a long time, a clear image is stably provided in the image formation of electrostatic recording. Also, this one does not contain heavy metals, etc.
Since it has a colorless positive charging performance, it is highly safe for the environment and can produce color toners and black toners.

Specific examples of the compound of the formula (1) to be contained in the toner as a charge control agent in the present invention include compounds represented by the following structural formulas, but are not limited thereto.

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Next, a synthesis example of the compound of the formula (1) of the present invention will be shown. The middle part of the synthesis examples represents parts by weight unless otherwise specified.

Synthesis Example 1 86.7 parts of triphenylphosphine was dissolved in 200 parts of xylene, and 40.0 parts of allyl bromide was added thereto.
Let react for hours. After cooling to 30 ° C., the resulting colorless crystals were filtered and washed with toluene to give allyltriphenylphosphonium bromide (Exemplified Compound 16).
22.7 parts (96.8%) are obtained.

Synthesis Example 2 88.2 parts of triphenylphosphine is dissolved in 240 parts of xylene, and 51.3 parts of cinnamyl chloride are added thereto, and the mixture is reacted at 130 ° C. for 4 hours. After allowing to cool to 30 ° C., the resulting colorless crystals are filtered and washed with toluene to obtain 117.4 parts (84.1%) of cinnamyltriphenylphosphonium chloride (Exemplified Compound 15).

Synthesis Example 3 9.6 parts of allyltriphenylphosphonium bromide synthesized in Synthesis Example 1 was added to water
A solution of 2.8 parts of sodium tetrafluoroborate in 9 parts of water is slowly added dropwise to the mixture, and the mixture is stirred for 5 hours. The resulting colorless crystals are collected by filtration and added to 200 parts of water. And 6.5 parts (66.4%) of allyltriphenylphosphonium tetrafluoroborate (Exemplified Compound 1).

Synthesis Example 4 69.2 parts of triphenylphosphine are dissolved in 200 parts of xylene, 23.9 parts of 2-butenyl chloride are added, and the mixture is reacted at 125 ° C. for 5 hours. After allowing to cool to 30 ° C., the resulting colorless crystals are filtered and washed with toluene to obtain 54.4 parts (58.5%) of 2-butenyltriphenylphosphonium chloride. Dissolve 8.8 parts of the obtained 2-butenyltriphenylphosphonium chloride in 20 parts of water, and slowly add dropwise a solution of 2.7 parts of sodium tetrafluoroborate in 9 parts of water, 6 hours. After stirring, the resulting colorless crystals were collected by filtration and washed with 300 parts of water.
After drying, 8.5 parts of 2-butenyltriphenylphosphonium tetrafluoroborate (Exemplified Compound 2) (83.
8%).

Synthesis Example 5 Dissolve 10.4 parts of cinnamyltriphenylphosphonium chloride synthesized in Synthesis Example 2 in 580 parts of water, and slowly add dropwise a solution of 2.7 parts of sodium tetrafluoroborate dissolved in 9 parts of water. After stirring for 6 hours, the resulting colorless crystals were collected by filtration, washed with 300 parts of water, and dried to obtain 10.1 parts (86.6%) of cinnamyltriphenylphosphonium tetrafluoroborate (Exemplary Compound 5). obtain.

Synthesis Example 6 Dissolve 10.4 parts of cinnamyltriphenylphosphonium chloride synthesized in Synthesis Example 2 in 580 parts of water, and slowly add a solution in which 5.2 parts of ammonium molybdate is dissolved in 233 parts of water. 5 hours After stirring, the resulting colorless crystals were collected by filtration, washed with 300 parts of water, and dried to obtain cinnamyltriphenylphosphonium molybdate (Exemplified Compound 18).
7.1 parts (51.4%) are obtained.

As a method for producing a toner containing the compound of the formula (1), a mixture comprising the compound of the formula (1), a colorant and a binder resin can be mixed by heating using a heating kneader or a two-roller. A method in which the mixture obtained by kneading the binder resin in a molten state with an apparatus and then cooling and solidifying the mixture is pulverized to a particle size of 3 to 20 μm with a pulverizer such as a jet mill or a ball mill. The compound is dissolved in a solvent (eg, acetone, ethyl acetate), stirred, thrown into water, reprecipitated, filtered, dried, and then pulverized with a pulverizer such as a ball mill.
Method obtained by grinding to a particle size of 20μ, formula (1)
And a monomer of the colorant and the binder resin are uniformly suspended in water, and the monomer is polymerized in fine particles under stirring to form a precipitate.The precipitate is filtered, washed with water, There is a method of drying to obtain a fine particle powder, and classifying this to obtain a target having a particle size of 3 to 20 μm. Also, a soft particle upper core material containing a low melting point resin for pressure fixing, a coloring component, a magnetic material, and the like ( Core particles) can 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. Further, the colored fine particles containing no charge control material are adjusted by the above method or the like, and then the compound of the formula (1) is fixedly added to the particle surface alone or together with an external additive such as colloidal silica by a mechanochemical method or the like. Can also.

In this case, the binder resin is usually 99 to 65.
%, More preferably 98 to 85%, and the colorant is 1.0 to 15%.
%, More preferably 1.5 to 10%, and the charge control agent is 0.1 to 0.1%.
To 30%, more preferably 0.3 to 5% (all by weight).

Examples of the colorant that can be used in the electrophotographic toner of the present invention include carbon black, ultramarine, iron black, activated carbon, copper oxide, manganese dioxide, graphite, zinc yellow, cadmium yellow, yellow iron oxide, and minerals. 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; Pigment Yellow 1, C
I. Pigment Red 9, CI. Pigment Blue 1
5. Aniline black, naphthol yellow S, benzidine yellow GR, quinoline yellow lake, anthrapyrimidine yellow, Hansa yellow G, permanent yellow NC
G, pyrazolone orange, indanthrene brilliant orange GK, pyrazolone red, brilliant carmine 6B, rhodamine lake B, quinacridone, alizarin lake, thioindigo red, thioindigo maroon, brilliant carmine 3B, methyl violet lake, dioxazine violet, aniline blue Organic pigments such as phthalocyanine blue, phthalocyanine blue, fast sky blue, indanthrene blue BC, phthalocyanine green, malachite green lake, and final yellow green G; Solvent Yellow 93, CI. Solven Yo Red 146,
CI. Solvent Blue 35, CI. Disperse Yellow 42, CI. Disperse Red 59, CI. Disperse Blue 81, CI. Solvent Red 49, CI. Solvent Red 52, CI. 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. Modant Red 30, CI. Direct Blue 2, CI. Acid Blue 9, CI. Basic Blue 3, CI. Basic Blue 5, CI. Acid Blue 15, CI. Modant Blue 7, CI. (CI
And the like, and oil-soluble dyes such as oil-soluble dyes.

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 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.

As the monomer of the binder resin, the monomer of the above resin is used, and specifically, vinyl aromatic carbon such as styrene, α-methylstyrene, vinyltoluene, chlorostyrene, ethylstyrene and divinylbenzene. Hydrogen monomer, acrylic acid, methacrylic acid, methyl acrylate,
Ethyl acrylate, butyl acrylate, acrylic acid-2
Monomers of acrylic compounds such as -ethylhexyl, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, phenyl methacrylate, acrylonitrile, methacrylic acid Monocarboxylic acids having a double bond such as lonitrile and acrylamide, maleic acid, methyl maleate, butyl maleate, dimethyl maleate, dicarboxylic acids such as phthalic acid, succinic acid, terephthalic acid, ethylene, propylene, butylene, and vinyl Vinyl monomers such as methyl ketone, vinyl hexyl ketone, vinyl methyl ether and vinyl isobutyl ether, ethylene glycol, diethylene glycol, triethylene glycol, 1, 2
-Propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, bisphenol A, polyol compounds such as hydrogenated bisphenol A, polyoxyethylenated bisphenol A, p-phenylene diisocyanate, p-xylylene Isocyanates such as range isocyanate, 1,4-tetramethylene diisocyanate, etc., amines such as ethylamine, butylamine, ethylenediamine, 1,4 diaminobenzene, 1,4 diaminobutane, monoethanolamine, diglycidyl ether, ethylene glycol diglycidyl ether And epoxy compounds such as bisphenol A glycidyl ether and hydroquinone diglycidyl ether can be used alone or in combination.

Further, the electrophotographic toner of the present invention requires a fluidizing agent such as silicon oxide, an anti-fogging agent such as mineral oil, various magnetic substances for one-component system, and a conductivity imparting agent such as zinc oxide. May be added accordingly. The toner obtained by the present invention is, for example, iron powder (carrier) of about 200 mesh.
And 3-8: 97-92 (toner: iron powder) to obtain a developer, which is used in a developing process in electrophotography. The toner for electrophotography of the present invention has a sharper charge amount distribution and better stability over time than toners using a conventional charge control agent. As a result, it is characterized in that an image with extremely high gradation is obtained and the repetitive image forming ability is extremely good.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. In the examples, parts are by weight unless otherwise specified.

Example 1 Styrene-butyl acrylate copolymer (binder) 100 parts Low molecular weight polyethylene 3 parts CI. Disperse Yellow 164 (colorant) 1.2 parts Compound of the above specific example (1) 1.5 parts

The mixture having the above composition was melt-mixed (10 minutes) in a kneader adjusted to 120 to 140 ° C., and then cooled and solidified. Next, after coarse pulverization by a coarse pulverizer, fine pulverization was performed by a jet mill pulverizer, and further classification was performed by an airflow classifier to obtain a toner having a particle size of 5 to 20 μm. The obtained toner 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 A. Next, when the initial specific charge amount of the developer A was measured by a blow-off charge amount measuring device, the result was +25.
It was 8 μC / g. Further, when copying was performed by a copying machine using this developer A, a clear yellow image was obtained with excellent gradation and without hindering the original hue of the colorant. In addition, a charge stability test (charge amount aging stability test, charge amount humidity resistance test) was performed using Developer A, and the results in Table 1 below were obtained.

Table 1 Stability test of charge amount over time (unit, + μC / g) Time (h) 0.08 0.25 0.5 1 3 6 22 Developer A 25.8 22.0 20.4 18.0 14.5 10.8 11.6 Charge amount moisture stability test (unit, + μC / g) g) Initial charge After moisture resistance test Rate of change (%) 25.8 21.0 -18.6

As described above, the stability of the developer A over time was extremely excellent.

The aging stability test was performed according to the following method. Stability test of charge amount over time: A developer (mixture of toner and iron powder carrier) is weighed in a poly container and contact-charged by a ball mill at 120 rpm for 22 hours, and the charge amount of the toner at that time is blow-off. It is measured by the method. Charge Amount Moisture Resistance Stability Test: Similar to the charge amount aging stability test, the developer is weighed in a poly container, the container is opened, and left under a condition of 34 ° C. and 86% RH for 2 days.
After contact charging with a ball mill at 5 rpm for 5 minutes, the charge amount of the toner is measured by a blow-off method. The rate of change is calculated as follows. Rate of change = (charge amount after humidity resistance test−initial charge amount at normal temperature and normal humidity) / initial charge amount at normal temperature and normal humidity × 100 (%)

Example 2 100 parts of a polyester resin 6.0 parts of carbon black 1.5 parts of the compound of the specific example (2)

After the mixture having the above composition was melt-mixed (10 minutes) in a kneader adjusted to 120 to 140 ° C.,
Cooled and solidified. Then, after coarse pulverization by a coarse pulverizer,
The mixture was finely pulverized with a jet mill pulverizer and further classified with an airflow classifier to obtain a toner having a particle size of 5 to 20 μm. The obtained toner was mixed with an iron powder carrier of about 200 mesh and 3: 9.
7 (toner: iron powder carrier) in a weight ratio 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 +21.6 μC.
/ G. Further, when a copying machine was used to make a copy using this developer B, a black image having excellent gradation was obtained. Further, a charging stability test was carried out in the same manner as in Example 1 using the developer B, and the results shown in Table 2 below were obtained.

Table 2 Stability test of charge amount over time (unit: + μC / g) Time (h) 0.08 0.25 0.5 1 3 6 22 Developer B 21.6 19.3 21.2 16.6 13.1 11.1 12.1 Charge amount moisture resistance test (unit: + μC / g) g) Initial charge After humidity resistance test Rate of change (%) 21.6 22.4 +3.7

As described above, the stability over time and the stability against moisture of the developer B were extremely excellent.

Example 3 Styrene-methyl acrylate copolymer 100 parts Low molecular weight polypropylene 3 parts CI. Solvent Blue 111 1.5 parts 1.5 parts of the compound of the above specific example (5)

The above mixture was dissolved in 1000 parts of a mixed solvent of acetone and ethyl acetate, and stirred at room temperature for 1 hour. Then, the mixture was dropped into 10,000 parts of water with stirring to cause precipitation. The resulting precipitate was filtered and dried to obtain a coarse particle toner. Next, fine pulverization was performed with a jet mill pulverizer, and further classification was performed with an airflow type classifier to obtain a 5-20 μm toner. Approximately 20
A 0-mesh iron powder carrier and a 3:97 (toner: iron powder carrier) weight ratio were mixed to obtain a developer C. Next, when the initial specific charge amount of the developer C was measured by a blow-off charge amount measuring device, it was +25.6 μC / g. Further, when copying was performed by a copying machine using this developer C, a clear blue image with excellent gradation and without hindering the original hue of the colorant was obtained. Further, a charging stability test was performed in the same manner as in Example 1 using the developer C, and the results shown in Table 3 below were obtained.

Table 3 Stability test of charge amount over time (unit: + μC / g) Time (h) 0.08 0.25 0.5 1 3 6 22 Developer C 25.6 24.3 23.5 22.0 18.5 15.9 16.5 Charge amount moisture stability test (unit, + μC / g) g) Initial charging After moisture resistance test Change rate (%) 25.6 30.2 +16.6

As described above, the stability of the developer C over time and the stability against humidity were extremely excellent.

Example 4 Epoxy resin 100 parts CI. Disperse Red 60 1.2 parts CI. Disperse Violet 17 0.3 part Specific compound (9) 2.0 parts

The mixture having the above composition was melt-mixed in a kneader adjusted to 110 to 130 ° C., and then spontaneously cooled and solidified. Next, fine pulverization is performed with a coarse pulverizer and a jet mill pulverizer, and the mixture is further classified with an airflow classifier to obtain a particle size of 5-
20 μ toner was obtained. 0.3 part of colloidal silica was mixed with 100 parts of the obtained toner using a Henschel mixer. This 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 D. Next, the initial specific charge amount of the developer D was measured by a blow-off charge amount measuring device.
It was 5.3 μC / g. Further, when copying was performed by a copying machine using this developer D, a clear red image was obtained which had excellent gradation and did not hinder the original hue of the colorant. Further, a charging stability test was performed in the same manner as in Example 1 using Developer D, and the results in Table 4 below were obtained.

Table 4 Stability Test with Charge Amount over Time (Unit, + μC / g) Time (h) 0.08 0.25 0.5 1 3 6 22 Developer D 25.3 24.1 22.5 21.3 20.6 21.4 21.0 Charge Amount Moisture Stability Test (unit, + μC / g g) Initial charge After moisture resistance test Rate of change (%) 25.3 25.1 -0.8

As described above, the stability of the developer D with time was extremely excellent.

Example 5 Epoxy resin 100 parts CI. Disperse Red 60 1.2 parts Specific compound (13) 2.0 parts

The mixture having the above composition was melted and mixed in a kneader adjusted to 120 to 130 ° C., and then naturally cooled and solidified. Next, fine pulverization is performed with a coarse pulverizer and a jet mill pulverizer, and the mixture is further classified with an airflow classifier to obtain a particle size of 5-
20 μ toner was obtained. 0.3 part of colloidal silica was mixed with 100 parts of the obtained toner using a Henschel mixer. This 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 E. Next, the initial specific charge amount of the developer E was measured by a blow-off charge amount measuring device.
It was 8.0 μC / g. Further, when copying was performed by a copying machine using this developer E, a clear red image was obtained with excellent gradation and without hindering the original hue of the colorant. Further, a charging stability test was carried out in the same manner as in Example 1 using the developer E, and the results shown in Table 5 below were obtained.

Table 5 Stability Test with Charge Amount over Time (Unit, + μC / g) Time (h) 0.08 0.25 0.5 1 3 6 22 Developer E 38.0 34.9 34.0 32.0 28.3 27.2 26.7 Charge Amount Moisture Stability Test (unit, + μC / g) g) Initial charge After moisture resistance test Rate of change (%) 38.0 36.1 -5.0

As described above, the stability over time of the developer E was extremely excellent.

Example 6 Styrene-butyl acrylate copolymer 100 parts Low molecular weight polyethylene 3 parts Kayaset Yellow 963 1.2 parts 1.5 parts of the compound of the above specific example (15)

The mixture having the above composition was melt-mixed (10 minutes) in a kneader adjusted to 125-140 ° C., and then cooled and solidified. Next, after coarse pulverization by a coarse pulverizer, fine pulverization was performed by a jet mill pulverizer, and further classification was performed by an air current classifier to obtain a toner having a particle size of 5 to 20 μm. The obtained toner 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 F. Next, the initial specific charge amount of the developer F was measured by a blow-off charge amount measuring device.
39.2 μC / g. Further, when copying was performed by a copying machine using this developer F, a clear yellow image was obtained which had excellent gradation and did not hinder the original hue of the colorant. Further, a charging stability test (charge amount aging change test, charging amount moisture resistance stability test) was performed in the same manner as in Example 1 using developer F, and the results in Table 6 below were obtained.

Table 6 Stability test with charge amount over time (unit: + μC / g) Time (h) 0.08 0.25 0.5 1 3 6 22 Developer F 39.2 34.8 34.1 31.6 27.5 24.6 21.5 Stability test with charge amount (unit, + μC / g) g) Initial charge After moisture resistance test Rate of change (%) 39.2 32.1-18.1

As shown in the above results, the stability of the developer F over time was extremely excellent.

Example 7 Methylstyrene monomer 75 parts Ethyl acrylate monomer 20 parts Kayaset Blue 814 1.8 parts Benzoyl peroxide 6 parts 2 parts of the compound of the above specific example (18)

The mixture having the above composition was mixed with a homomixer using a homomixer.
Stir and mix for 1 minute to obtain a homogeneous liquid,
Parts / magnesium carbonate: added to 2.3 parts of the dispersion and stirred with a homomixer at 6500 rpm for 5 minutes to obtain a uniform suspension. The suspension was placed in a 300 ml three-necked flask, and the polymerization reaction was carried out at 70 ° C. for 5 hours while stirring at 200 rpm. And dried to a particle size of 5 to 2
0 μ toner was obtained. 0.3 part of colloidal silica was mixed with 100 parts of the obtained toner using a Henschel mixer. This 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 G. Next, the initial specific charge amount of the developer G was measured by a blow-off charge amount measuring device.
1.2 μC / g. Further, when copying was performed by a copying machine using this developer G, a clear blue image was obtained, which was excellent in gradation and did not hinder the original hue of the colorant. Further, a charging stability test was carried out in the same manner as in Example 1 using the developer G, and the results in Table 7 below were obtained.

Table 7 Stability test with charge amount over time (unit, + μC / g) Time (h) 0.08 0.25 0.5 1 3 6 22 Developer G 21.2 30.8 31.4 33.3 32.5 30.5 28.4 Charge amount with moisture stability test (unit, + μC / g g) Initial charge After moisture resistance test Rate of change (%) 21.2 23.1 +9.0

As described above, the stability of the developer G with time was extremely excellent.

Examples 8-45 Developers were prepared in the same manner as in Example 1 by using the compounds shown in the column of "Specific Examples of Compounds" and the coloring agents shown in the column of "Coloring Agent". The initial specific charge amount of each of the toners was measured, and a aging stability test was performed in the same manner as in Example 1. The toner using any of the compounds showed little change in the amount of charge, and the stability over time of the developer was extremely excellent. When the images were copied with a copying machine, all of the developing agents were excellent in gradation, and a clear image having the original hue of the colorant was obtained.

Table 8 Change in charge amount over time (+ μC / g) Example Compound Coloring agent Time (h) No. 0.08 0.25 0.5 1 3 6 22 8. Specific example CI.Dis.Y.164 25.8 25.0 22.6 20.5 19.7 17.6 18.1 3 9. Specific examples 〃 22.3 23.4 20.8 19.9 14.5 14.3 14.8 4 10. Specific examples 〃 23.1 21.4 20.2 20.5 18.7 13.6 12.9 6 11. Specific example 〃 21.2 20.9 19.5 17.5 14.8 14.4 14.9 7 12. Specific example CI.Pig.R.9 24.3 22.2 20.9 18.6 17.3 17.5 17.5 8 13. Specific examples 〃 26.2 26.3 26.3 26.5 26.8 26.4 25.0 10 14. Specific examples 〃 17.6 17.4 17.0 16.9 16.6 15.9 13.8 11 Colorant CI. : Color Index, Sol: Solvent Dis: Disperse, Pig: Pigment, B: Blue, R: Red, Y: Yellow, and Kayaset are trade names of Nippon Kayaku Co., Ltd.

7. Continuation of Table 8 Charge Amount Moisture Resistance Stability Test (+ μC / g) Example No. Compound Initial Charge After Moisture Resistance Test Rate of Change (%) Specific Example 3 25.8 20.1 -22.1 9. Specific example 4 22.3 21.9-1.8 Specific example 6 23.1 19.5-15.6 11. Specific example 7 21.2 20.2-4.7 12. Specific Example 8 24.3 19.6-19.3 13. Specific example 10 26.2 25.8-1.5 14. Specific example 11 17.6 15.3 -13.1

Table 9 Coulomb time course test (+ μC / g) Example Compound Coloring agent Time (h) No. 0.08 0.25 0.5 1 3 6 22 15. Specific example 〃 21.9 19.3 19.5 18.5 17.0 15.4 12.1 12 16. Specific example 〃 20.7 19.9 19.9 18.4 16.6 15.6 13.4 14 17. Specific example CI.Pig.Y.1 23.8 22.6 22.9 21.1 20.3 18.0 15.6 16 18. Specific examples 〃 34.8 32.6 32.9 30.8 29.4 27.8 25.8 20 19. Specific example CI.Sol.R.146 25.6 24.6 22.2 20.3 18.4 18.3 19.5 21 20. Specific examples 〃 25.2 24.5 25.5 20.8 18.8 18.9 19.3 22 21. Specific example Kayaset.Y.963 27.9 28.6 25.4 23.0 20.6 20.4 21.4 23 22. Specific examples 〃 27.2 28.2 27.3 27.4 26.0 25.6 23.9 24 23. Specific examples 〃 23.7 22.9 21.8 20.6 19.5 19.8 17.1 25 24. Specific examples 〃 25.0 25.1 25.1 25.8 24.4 24.6 23.2 26 25. Specific example CI.Pig.R.146 22.3 20.3 21.0 18.4 16.8 17.2 17.8 27 26. Example 〃 31.5 27.6 27.2 25.8 21.4 21.8 20.1 28

Continuation of Table 9 Charge Amount Moisture Resistance Stability Test (+ μC / g) Example No. Compound Initial Charge After Moisture Resistance Test Rate of Change (%) 15. Specific Example 12 21.9 20.8-5.0 Specific Example 14 20.7 20.1-2.9 17. Specific Example 16 23.8 19.7-17.2 18. Specific Example 20 34.8 27.9-19.8 19. Specific Example 21 25.6 20.1 -21.5 20. Specific Example 22 25.2 24.3-3.6 21. Specific Example 23 27.9 22.6-19.0 22. Specific Example 24 27.2 27.0-0.7 23. Specific Example 25 23.7 28.1 +18.6 24. Specific Example 26 25.0 23.7-5.2 25 Specific Example 27 22.3 21.2-1.0 26 Specific Example 28 31.5 25.3-19.7

Table 10 Change in charge amount over time (+ μC / g) Example Compound Coloring agent Time (h) No. 0.08 0.25 0.5 1 3 6 22 27. Specific example CI.Dis.R.60 23.9 22.7 20.5 20.1 20.0 20.3 18.2 29 28. Specific examples Carbon black 22.5 20.7 19.9 17.6 16.8 12.4 13.2 30 29. Specific examples 〃 23.0 22.2 23.1 19.9 16.5 14.4 14.9 31 30. Specific example CI.Pig.R.146 38.5 34.5 34.8 31.6 28.9 25.5 22.6 34 31. Specific examples 〃 38.7 35.1 32.2 32.8 30.4 28.6 25.3 35 32. Specific example CI.Sol.B.111 27.8 26.1 25.0 24.6 21.5 19.8 19.5 36 33. Specific examples 〃 22.7 20.8 19.2 17.0 16.5 12.3 12.9 38 34. Specific example CI.Dis.R.60 25.9 23.8 20.7 16.7 16.9 14.6 15.7 40 35. Specific example CI.Dis.B.81 26.4 24.8 23.4 23.2 20.3 18.7 19.1 42 36. Specific examples 〃 15.4 16.0 16.4 14.7 13.9 11.5 11.4 44 37. Specific example CI.Dis.B.35 22.1 20.4 22.5 18.6 15.4 13.9 14.5 46 38. Example 〃 23.2 30.8 31.2 33.7 32.0 30.5 28.7 47

Table 10 Continuity Charge Amount Moisture Resistance Stability Test (+ μC / g) Example No. Compound Initial Charge After Moisture Resistance Test Rate of Change (%) 27. Specific Example 29 23.9 20.7 -13.4 28. Specific Example 30 22.5 18.0 -20.0 29. Specific Example 31 23.0 22.1-3.9 30. Specific Example 34 38.5 31.1-19.2 31. Specific Example 35 38.7 32.5 -16.0 32. Specific Example 36 27.8 28.3 + 1.8 33. Specific Example 38 22.7 19.2-15.4 34. Specific Example 40 25.9 22.7 -12.4 35. Specific Example 42 26.4 28.5 + 8.0 36. Specific Example 44 15.4 13.9-9.7 37. Specific Example 46 22.1 21.8-1.4 38. Specific example 47 23.2 22.9-1.3

Table 11 Change in charge amount over time (+ μC / g) Example Compound Colorant Time (h) No. 0.08 0.25 0.5 1 3 6 22 39. Specific example CI.Dis.R.60 22.3 21.0 20.9 18.8 15.7 11.9 12.5 48 40. Specific example carbon black 25.8 24.4 23.7 22.9 18.5 16.7 16.7 52 41. Specific examples 〃 23.8 29.6 30.3 32.0 31.2 29.9 27.5 54 42. Specific example CI.Pig.R.146 32.4 32.6 32.9 31.0 26.8 23.4 20.9 57 43. Specific example 〃 27.7 25.1 21.2 20.8 20.4 18.6 16.2 58 44. Specific examples 〃 27.7 26.1 25.2 24.8 20.4 17.6 18.1 62 45. Example 〃 28.1 24.1 22.2 20.8 17.4 13.6 13.8 65

Continuation of Table 11 Charge Amount Moisture Resistance Stability Test (+ μC / g) Example No. Compound Initial Charge After Moisture Resistance Test Rate of Change (%) 39. Specific Example 48 22.3 17.9-19.7 40. Specific Example 52 25.8 28.0 + 8.5 41. Specific example 54 23.8 23.1-1.0 42. Specific Example 57 32.4 25.3-21.9 43. Specific example 58 27.7 22.9-17.3 44. Specific example 62 27.7 24.1 -13.0 45. Specific Example 65 28.7 23.0-19.9

[0088]

The toner for electrophotography obtained by the present invention has a sharper charge distribution, moisture resistance and stability over time than toners using conventional charge control agents. As a result, it is characterized in that an image having extremely high gradation is obtained and the repetitive image forming ability is extremely good. Further, since the charge control agent itself is essentially colorless, any colorant can be selected according to the hue required for the color toner, and the original hue of the dye or pigment is not changed at all. Another characteristic is that it does not interfere.

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Continuation of the front page (56) References JP-A-61-120167 (JP, A) JP-A-60-213960 (JP, A) JP-A-61-156142 (JP, A) (58) Fields investigated (Int) .Cl. ⁶ , DB name) G03G 9/097

Claims (1)

(57) [Claims] 1. An electrophotographic toner comprising at least one compound represented by the following formula (1): ## STR1 ## [In the formula (1), R ₁ , R ₂ and R _{3 each} have 4 to 4 carbon atoms.
8 represents an alkyl group, a substituted or unsubstituted aryl group, or a benzyl group, and R ₄ represents an alkenyl group, 3-phenyl-
2-propenyl group, alkynyl group, or 3-phenyl-
It represents a 2-propynyl group, X ^- represents an anion. ]