JPH1184736A - Positively electrostatic-chageable toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the durability of a developer and to ensure stable electrostatic chargeability independently of the change of environment such as temp. and humidity, by incorporating a salification compd. comprising plural specified reaction forming compds. as an electric charge controlling agent. SOLUTION: In this positively electrostatic-chargeable toner contg. a colorant, a thermoplastic resin and an electric charge controlling agent, a salification compd. comprising reaction forming compds. represented by the formula nA<+> (I) and formula II is contained as the electric charge controlling agent. In the formula I, A<+> is a cation contg. a quat. N atom or a tert. S atom and (n) is 1 or 2. In the formula II, B is a monovalent anion, H, hydroxyl or lower alkyl. A salification compd. using a specified dihydroxyanthraquione anion represented by formula III is preferably contained. In the formula III, A<+> is a cation contg. a quat. N atom or a tert. S atom.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positively chargeable toner used for developing an electrostatic latent image in electrophotography, electrostatic recording and the like, and more particularly to a charge control agent having high thermal stability. And a positively chargeable toner.

[0002]

2. Description of the Related Art Generally, in electrophotography, a toner image having a positive or negative charge is electrostatically attached to an electrostatic latent image formed on a photoconductive member, and then the toner image is transferred onto a transfer paper. Then, the image is formed by fixing. The toner used for this is a particle having an average particle diameter of 5 to 20 μm comprising a binder resin and a colorant as main components, and is controlled to an appropriate charge amount by a frictional charging member such as a carrier or a charging blade. When the charge amount of the toner is larger than the appropriate value, the image density is lowered, and when the charge amount of the toner is smaller than the appropriate value, toner scattering, background fog, etc. occur, resulting in deterioration of image quality.

Usually, a charge control agent is added to a toner to prevent these problems. As a charge control agent added to a positively chargeable toner, a nigrosine dye,
Pyridinium salts, ammonium salts, and their lake compounds have been used.

[0004]

However, in these charge control agents, chlorine ions, bromine ions, iodine ions, perchlorate ions and the like having high hydrophilicity are used as anions, so that the moisture resistance as a charge control agent is low. It is not sufficient, and there is a problem that the charge amount of the toner is difficult to stabilize against a change in humidity. As a countermeasure, the long-chain alkyl group is introduced into the cation part, or the moisture resistance is increased by resin acid denaturation or lake formation, but at the same time the melting point of the charge control agent becomes too low. Or, the crystals may be too hard, making it difficult to uniformly and finely disperse these compounds in the binder resin. If the dispersibility is poor, the charge control agent is likely to be detached, causing contamination of a charging member such as a carrier. As a result, there has been a problem that the toner charge amount is reduced and toner scattering and background fog are likely to occur.

As described above, it is difficult for the conventional charge control agent to achieve both charge stability with respect to humidity and good dispersibility in a resin. It has been difficult to simultaneously eliminate a plurality of drawbacks, such as the fact that the carrier surface is contaminated due to long-term use and the charge amount is reduced.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a positively chargeable toner having a stable chargeability with respect to the durability of a developer and environmental changes in temperature and humidity.

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have incorporated a salt-forming compound comprising a reaction product represented by the following general formulas [a] and [b].
It has been found that a positively chargeable toner having stable chargeability with respect to environmental changes in temperature and humidity can be obtained. General formula [a] nA ⁺ General formula [b]

[0008]

Embedded image

In the general formula [a], A ⁺ represents a cation containing a quaternary nitrogen atom or a tertiary sulfur atom. General formula [b]
In the formula, B represents a monovalent anion, hydrogen, a hydroxyl group, or a lower alkyl group. Further, n is an integer of 1 or 2.

[0010] By using a specific dihydroxyanthraquinone ion as an anion of the charge control agent comprising these salt-forming compounds, that is, by containing a salt-forming compound represented by the following general formula [I],
It has been found that a positively chargeable toner having excellent stability over time and having stable charge characteristics with respect to changes in temperature and humidity can be obtained. General formula [I]

[0011]

Embedded image

In the general formula [I], A ⁺ represents a cation containing a quaternary nitrogen atom or a tertiary sulfur atom.

Among the above charge control agents, particularly, the salt-forming compounds represented by the following general formula [II], that is, the compound examples (5) to (26) shown below are used in the process of producing a positively chargeable toner. It has been found that color change hardly occurs even during heating and kneading, and is suitable as a charge control agent for color toner. General formula [II]

[0014]

Embedded image

In the general formula [II], R _{1 to} R ₄ are an alkyl group,
Indicates an aryl group or an aralkyl group. They may also contain substituents.

Specific examples of R _{1 to} R ₄ are as follows. That is, methyl, ethyl, propyl, iso-propyl, butyl, iso-butyl, sec-butyl, ter
alkyl groups such as t-butyl, amyl, iso-amyl and iso-octyl; aryl groups such as phenyl, tolyl and naphthyl; aralkyl groups such as benzyl, phenylethyl, methylbenzyl and naphthylmethyl. Among the charge control agents, the following general formula [III]
, Ie, compound examples (2) to (4), compound examples (8), compound examples (9), compound examples (11) to compound examples (13), and compound examples (16). -Compound Example (25) and the like were found to be easily crystallized at the time of synthesis, and a large amount of charge control agent was obtained. General formula [III]

[0017]

Embedded image

In the general formula [III], A ⁺ represents a cation containing a quaternary nitrogen atom or a tertiary sulfur atom.

Next, specific examples of the compounds represented by the general formulas [I], [II], and [III] are listed, but the present invention is not limited to them. Any of these can be suitably used as a charge control agent.

Compound Example (1)

[0021]

Embedded image

Compound Example (2)

[0023]

Embedded image

Compound Example (3)

[0025]

Embedded image

Compound Example (4)

[0027]

Embedded image

Compound Example (5)

[0029]

Embedded image

Compound Example (6)

[0031]

Embedded image

Compound Example (7)

[0033]

Embedded image

Compound Example (8)

[0035]

Embedded image

Compound Example (9)

[0037]

Embedded image

Compound Example (10)

[0039]

Embedded image

Compound Example (11)

[0041]

Embedded image

Compound Example (12)

[0043]

Embedded image

Compound Example (13)

[0045]

Embedded image

Compound Example (14)

[0047]

Embedded image

Compound Example (15)

[0049]

Embedded image

Compound Example (16)

[0051]

Embedded image

Compound Example (17)

[0053]

Embedded image

Compound Example (18)

[0055]

Embedded image

Compound Example (19)

[0057]

Embedded image

Compound Example (20)

[0059]

Embedded image

Compound Example (21)

[0061]

Embedded image

Compound Example (22)

[0063]

Embedded image

Compound Example (23)

[0065]

Embedded image

Compound Example (24)

[0067]

Embedded image

Compound Example (25)

[0069]

Embedded image

Compound Example (26)

[0071]

Embedded image

Compound Example (27)

[0073]

Embedded image

Compound Example (28)

[0075]

Embedded image

The positively chargeable toner of the present invention has a charge product represented by the general formulas [a] and [b], the general formulas [I], [II] and [III]. It is desirable that the control agent is added in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the thermoplastic resin. When the amount is less than 0.1 part by weight, the effect of charge control is small,
If it exceeds 10 parts by weight, it will be difficult to finely disperse it in the resin. A more preferable amount of the charge control agent is,
It is 0.5 to 5 parts by weight based on 100 parts by weight of the resin. Further, in order to improve the quality of the positively chargeable toner, for example, additives such as a fluidity improver and an image peeling preventive may be added internally or externally.

Further, in the positively chargeable toner of the present invention, the ratio of the charge control agent present on the surface of the positively chargeable toner may be in the range of 0.5 to 1.5% by weight based on the whole. desirable. If the ratio of the charge control agent on the surface of the positively chargeable toner is less than 0.5% by weight, it is difficult to obtain the effect of the charge control agent. On the other hand, if the ratio of the charge control agent on the surface of the positively chargeable toner exceeds 1.5% by weight, the charge control agent on the surface of the positively chargeable toner is released during a long-term use of the positively chargeable toner, and the charge amount is significantly increased. Changes to More preferably, the charge control agent concentration on the surface of the positively chargeable toner is 0.8 to 1.2% by weight.

Examples of the resin used for the positively chargeable toner of the present invention include the following known toner resins or binder resins. That is, styrene resin, styrene-acrylic resin, styrene-acrylonitrile resin, acrylic resin, styrene-butadiene resin,
Styrene-maleic acid resin, styrene-methacrylic resin, vinyl chloride resin, vinyl acetate resin, olefin resin, epoxy resin, urethane resin, ester resin and the like. These resins can be used alone or as a blend of several types.

In the positively chargeable toner of the present invention, many known dyes and pigments can be used as the colorant. That is, carbon black, magnetic powder, or nitro, azo, stilbene azo, diphenylmethane, triphenylmethane, methine, thiazole,
Anthraquinone-based, indamine-based, azine-based, oxaazine-based, thiazine-based, sulfur dye-based, indigoid-based, phthalocyanine-based organic dye or pigment, or inorganic pigment, or metal salt of acid dye, basic dye and phosphoric acid,
Lake pigments typified by salts with molybdic acid, tungstic acid, and the like are included.

The positively chargeable toner of the present invention is produced, for example, as follows. That is, the above-mentioned resins, colorants and reaction products of general formulas [a] and [b], and charge control agents represented by general formulas [I], [II] and [III] , And, if necessary, after sufficiently mixing a fluidizing agent or the like with a mixer, melt-kneading using a twin-screw kneader, cooling and solidifying, and then pulverizing with a jet mill to obtain an average particle diameter of 5 to 25 μm. A positively chargeable toner can be obtained.

When the positively chargeable toner of the present invention is used as a two-component developer, the positively chargeable toner can be mixed with a carrier powder and developed by a two-component magnetic brush development method or the like.

As the carrier, all known carriers can be used. For example, iron powder, nickel powder, ferrite powder, glass beads and the like having a particle size of about 50 to 200 μm are exemplified.

When the positively chargeable toner of the present invention is used as a one-component developer, when the positively chargeable toner is manufactured as described above, for example, a ferromagnetic material such as iron powder, nickel powder, and ferrite powder is used. Can be added and dispersed for use. In this case, examples of the developing method include a contact developing method and a jumping developing method.

Since the salt-forming compound of the present invention comprises an anion having low solubility in water, it has higher moisture resistance than a salt-forming compound comprising a halogen ion or an organic sulfonic acid anion, and contains a positively chargeable toner containing the same. Has excellent charge stability against humidity. Further, the salt forming compound of the present invention has excellent thermal stability even at the temperature of kneading for heating at the time of producing the positively chargeable toner, usually at a temperature of 120 ° C. to 180 ° C., and obtains stable quality at the time of producing the positively chargeable toner. Can be. In addition, since the dispersibility of the positively chargeable toner in the binder resin is good, the positively chargeable toner containing the toner is less contaminated to a frictionally charging member such as a carrier or a charging blade,
Maintains stable charging performance for a long time even during continuous copying.

Further, those using a quaternary ammonium salt as a cation have little light absorption in the visible light range and are hardly discolored even during heating and kneading in the positively chargeable toner production process. It can also be applied.

Further, by using a specific 2,6-dihydroxyanthraquinone as an anion, crystallization at the time of synthesis becomes easy, and stable quality can be maintained.

[0087]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a method for synthesizing a charge control agent used in the present embodiment will be described first.

(Synthesis Example 1) 10 ml of methanol and 10
0.240 g (1 mmol) of 1,2-dihydroxyanthraquinone and 0.04 g in a mixed solvent of distilled water
g (1 mmol) of sodium hydroxide is stirred at 90 ° C. for 10 minutes to obtain the sodium salt.

In a mixed solvent of 5 ml of methanol and 5 ml of distilled water, 0.320 g (1 mmol) of methylene blue was stirred at 90 ° C. for 10 minutes, mixed with the sodium salt, and further stirred at 90 ° C. for 10 minutes.

The solution was allowed to cool to room temperature by standing, and the precipitate was filtered. The collected product was washed with distilled water and dried to obtain 0.20 g of a dark brown powder (Compound Example (1)) (yield: 38.2%). This material was insoluble in water and had a melting point of 272.0 ° C. Table 1 shows the results of measurement of this dark brown powder by elemental analysis.

(Synthesis Example 2) 10 ml of methanol and 10
0.240 g (1 mmol) of 2,6-dihydroxyanthraquinone and 0.04 g in a mixed solvent of distilled water
g (1 mmol) of sodium hydroxide is stirred at 90 ° C. for 10 minutes to obtain the sodium salt.

In a mixed solvent of 5 ml of methanol and 5 ml of distilled water, 0.570 g (1 mmol) of crystal violet was stirred at 90 ° C. for 10 minutes, mixed with the sodium salt, and further stirred at 90 ° C. for 10 minutes. .

The solution was allowed to cool to room temperature by standing, and the precipitate was filtered. The collected material was washed with distilled water and dried to obtain 0.60 g of a pale purple powder (Compound Example (2)) (yield 98.1%). This material was insoluble in water and had a melting point of 198.0 ° C. Table 1 shows the results of measurement of the light purple powder by elemental analysis.

(Synthesis Example 3) 5 ml of methanol and 5 ml
0.351 g (1 mmol) in a mixed solvent of distilled water
Was stirred at 90 ° C. for 10 minutes, mixed with the sodium salt obtained by the same operation as in Synthesis Example 2, and further stirred at 90 ° C. for 1 minute.
Stirred for 0 minutes.

The solution was allowed to cool to room temperature by standing, and the precipitate was filtered. The collected material was washed with distilled water and dried to obtain 0.50 g of a dark brown powder (Compound Example (3)) (yield: 90.2%). This material was insoluble in water and had a melting point of 300.0 ° C. Table 1 shows the results of measurement of this dark brown powder by elemental analysis.

(Synthesis Example 4) 5 ml of methanol and 5 ml
0.299 g (1 mmol) in a mixed solvent of distilled water
Of 1,3-dibenzylbenzimidazolium was stirred at 90 ° C. for 10 minutes, mixed with the sodium salt obtained by the same operation as in Synthesis Example 2, and further stirred at 90 ° C. for 10 minutes.

The solution was allowed to cool to room temperature by standing, and the precipitate was filtered. The collected material was washed with distilled water and dried to obtain 0.37 g of a deep reddish purple powder (Compound Example (4)) (yield: 68.7%). This material was insoluble in water and had a melting point of 241.4 ° C. Table 1 shows the results of elemental analysis of the deep red purple powder.

(Synthesis Example 5) 5 ml of methanol and 5 ml
0.110 g (1 mmol) in a mixed solvent of distilled water
Was stirred at 90 ° C. for 10 minutes, mixed with the sodium salt obtained by the same operation as in Synthesis Example 1, and further stirred at 90 ° C. for 10 minutes.

The solution was allowed to cool to room temperature by standing, and the precipitate was filtered. The collected material was washed with distilled water and dried to obtain 0.20 g of a light brown powder (Compound Example (5)) (yield: 63.8%). This material was insoluble in water and had a melting point of 237.2 ° C. Table 1 shows the results of measurement of the light brown powder by elemental analysis.

Synthesis Example 6 10 ml of methanol and 10
0.240 g (1 mmol) of 1,8-dihydroxyanthraquinone and 0.04 g in a mixed solvent of distilled water
g (1 mmol) of sodium hydroxide is stirred at 90 ° C. for 10 minutes to obtain the sodium salt.

In a mixed solvent of 5 ml of methanol and 5 ml of distilled water, 0.210 g (1 mmol) of tetraethylammonium bromide was stirred at 90 ° C. for 10 minutes, mixed with the sodium salt, and further stirred at 90 ° C. for 10 minutes. did.

The solution was allowed to cool to room temperature by standing, and the precipitate was filtered. The collected material was washed with distilled water and dried to obtain 0.22 g of a light brown powder (Compound Example (6)) (yield: 59.5%). This material was insoluble in water and had a melting point of 208.2 ° C. Table 1 shows the results of measurement of the light brown powder by elemental analysis.

(Synthesis Example 7) 5 ml of methanol and 5 ml
0.322 g (1 mmol) in a mixed solvent of distilled water
Of tetrabutylammonium bromide was stirred at 90 ° C. for 10 minutes, mixed with the sodium salt obtained by the same operation as in Synthesis Example 2, and further stirred at 90 ° C. for 10 minutes.

The solution was allowed to cool to room temperature by standing, and the precipitate was filtered. The filtered product was washed with distilled water and dried to obtain 0.18 g of a glossy orange powder (Compound Example (9)) (yield: 37.4%). This material was insoluble in water and had a melting point of 257.7 ° C. Table 1 shows the results of the glossy orange powder measured by elemental analysis.

(Synthesis Example 8) 5 ml of methanol and 5 ml
0.172 g (1 mmol) in a mixed solvent of distilled water
Of phenyltrimethylammonium bromide was stirred at 90 ° C. for 10 minutes, mixed with the sodium salt obtained by the same operation as in Synthesis Example 2, and further stirred at 90 ° C. for 10 minutes.

The solution was allowed to cool to room temperature by standing, and the precipitate was filtered. The collected material was washed with distilled water and dried to obtain 0.24 g of a dark brown powder (Compound Example (13)) (yield: 63.9%). This material was insoluble in water and had a melting point of 222.0 ° C. Table 1 shows the results of measurement of this dark brown powder by elemental analysis.

(Synthesis Example 9) 5 ml of methanol and 5 ml
0.186 g (1 mmol) in a mixed solvent of distilled water
Of benzyltrimethylammonium chloride was stirred at 90 ° C. for 10 minutes, mixed with the sodium salt obtained by the same operation as in Synthesis Example 2, and further stirred at 90 ° C. for 10 minutes.

The solution was allowed to cool to room temperature by standing, and the precipitate was filtered. The collected material was washed with distilled water and dried to obtain 0.25 g of a dark brown powder (Compound Example (22)) (yield: 64.2%). This material was insoluble in water and had a melting point of 265.2 ° C. Table 1 shows the results of measurement of this dark brown powder by elemental analysis.

(Synthesis Example 10) 5 ml of methanol and 5 m
In a mixed solvent of 1 l of distilled water, 0.312 g (1 mmol) of benzyltributylammonium chloride
The mixture was stirred at 10 ° C for 10 minutes, mixed with the sodium salt obtained by the same operation as in Synthesis Example 2, and further stirred at 90 ° C for 10 minutes.

The solution was allowed to cool to room temperature by standing, and the precipitate was filtered. The collected material was washed with distilled water and dried to obtain 0.39 g of dark brown powder (Compound Example (25)) (yield: 75.6%). The melting point of this material was 243.2 ° C. Table 1 shows the results of measurement of this dark brown powder by elemental analysis.

[0111]

[Table 1]

(Examples) Next, the present invention will be described in detail with reference to examples, but of course, the present invention is not limited to these. In the following description, “parts by weight” is abbreviated as “parts”.

(Example 1) The positively chargeable toner of the present invention
Styrene / acrylic copolymer resin [ESLEK P-598 (trade name) manufactured by Sekisui Chemical Co., Ltd.] 100 parts carbon black [MA-100 (trade name) manufactured by Mitsubishi Chemical Corporation] 6 parts Compound example (5) 2 parts The above-mentioned composition was uniformly premixed with a high-speed mixer. Next, the mixture was melt-kneaded by a twin-screw kneader, cooled, and coarsely ground by a hammer mill. The obtained crushed product was finely pulverized using a jet mill equipped with a classifier to obtain a black toner having a particle size of 10.81 μm. The obtained positively chargeable toner particles were stirred in methanol at 0 ° C. for 30 minutes to extract a charge control agent present on the surface of the positively chargeable toner, and the extract was quantified using high performance liquid chromatography. The charge control agent was present at 1.01% by weight on the surface of the positively chargeable toner.

A developer was prepared by mixing 2 parts of the obtained positively chargeable toner with 98 parts of a ferrite carrier [FS-660 (trade name) manufactured by Kanto Denka Kogyo KK].

When the blow-off charge of the developer was measured using a blow-off powder charge measuring device manufactured by Toshiba Chemical Corporation, the charge was constant and excellent charge controllability was obtained. Table 2 shows the charge amount.

When an image was formed using a commercially available copying machine [manufactured by SF-8300 Sharp] using the positively chargeable toner, the toner had stable chargeability in continuous copying of 20,000 sheets and was free from fog. A black image with good fine line reproducibility was obtained.

(Example 2) The positively chargeable toner of the present invention
Styrene / acrylic copolymer resin [S-LEC P-598 (trade name) manufactured by Sekisui Chemical Co., Ltd.] 100 parts carbon black [MA-100 (trade name) manufactured by Mitsubishi Kasei Corporation] 6 parts Compound Example (6) 2 parts The above compound was treated in the same manner as in Example 1 to obtain a particle size of 10.69.
A black toner having a charge control agent concentration of 1.01% by weight on the surface of the positively chargeable toner was obtained, and a developer was prepared.

When the blow-off charge of the developer was measured using a blow-off powder charge measuring device manufactured by Toshiba Chemical Corporation, excellent charge controllability was obtained. Table 2 shows the charge amount.

Further, when an image was formed using a commercially available copying machine [manufactured by SF-8300 Sharp] using the positively chargeable toner, the toner had stable chargeability in continuous copying of 20,000 sheets, and was free from fog. A black image with good fine line reproducibility was obtained.

(Example 3) The positively chargeable toner of the present invention
Styrene / acrylic copolymer resin [ESLEK P-598 (trade name) manufactured by Sekisui Chemical Co., Ltd.] 100 parts carbon black [MA-100 (trade name) manufactured by Mitsubishi Chemical Corporation] 5 parts Compound Example (9) 2 parts The above compound was treated in the same manner as in Example 1 to obtain a particle size of 10.22.
A black toner having a charge control agent concentration of 0.94% by weight on the surface of the positively chargeable toner having a thickness of μm was obtained, and a developer was prepared.

When the blow-off charge of the developer was measured using a blow-off powder charge measuring device manufactured by Toshiba Chemical Corporation, excellent charge controllability was obtained. Table 2 shows the charge amount.

When an image was formed using a commercially available copying machine [manufactured by SF-8300 Sharp] using the positively chargeable toner, the toner had a stable charge amount in continuous copying of 20,000 sheets and was free from fog. A black image with good fine line reproducibility was obtained.

(Example 4) The positively chargeable toner of the present invention
Styrene / acrylic copolymer resin [ESLEK P-598 (trade name) manufactured by Sekisui Chemical Co., Ltd.] 100 parts carbon black [MA-100 (trade name) manufactured by Mitsubishi Chemical Corporation] 6 parts Compound Example (13) 2 parts The above compound was treated in the same manner as in Example 1 to obtain a particle size of 10.55.
A black toner having a charge control agent concentration of 1.11% by weight on the surface of the positively chargeable toner was obtained, and a developer was prepared.

When the blow-off charge of the developer was measured using a blow-off powder charge measuring device manufactured by Toshiba Chemical Corporation, excellent charge controllability was obtained. Table 2 shows the charge amount.

Further, when an image was formed using a commercially available copying machine [manufactured by SF-8300 Sharp] using the positively chargeable toner, the toner had stable chargeability in continuous copying of 20,000 sheets and was free from fog. A black image with good fine line reproducibility was obtained.

(Example 5) The positively chargeable toner of the present invention
Styrene / acrylic copolymer resin [S-LEC P-598 (trade name) manufactured by Sekisui Chemical Co., Ltd.] 100 parts carbon black [MA-100 (trade name) manufactured by Mitsubishi Kasei Corporation] 6 parts Compound Example (15) ... 3 parts The above formulation was treated in the same manner as in Example 1 to give a particle size of 9.854.
A black toner having a charge control agent concentration of 1.15% by weight on the surface of the positively chargeable toner was obtained, and a developer was prepared.

The blow-off charge of the developer was measured using a blow-off powder charge measuring device manufactured by Toshiba Chemical Corporation. As a result, excellent charge controllability was obtained. Table 2 shows the charge amount.

Further, when an image was formed using a commercially available copying machine [manufactured by SF-8300 Sharp] using the positively chargeable toner, the toner had stable chargeability in continuous copying of 20,000 sheets, and was free from fog. A black image with good fine line reproducibility was obtained.

(Example 6) The positively chargeable toner of the present invention
Styrene / acrylic copolymer resin [ESLEK P-598 (trade name) manufactured by Sekisui Chemical Co., Ltd.] 100 parts carbon black [MA-100 (trade name) manufactured by Mitsubishi Chemical Corporation] 6 parts Compound example (20) 3 parts The above compound was treated in the same manner as in Example 1 to obtain a particle size of 10.01.
A black toner having a charge control agent concentration of 1.09% by weight on the surface of the positively chargeable toner was obtained, and a developer was prepared.

When the blow-off charge of the developer was measured using a blow-off powder charge measuring device manufactured by Toshiba Chemical Corporation, excellent charge controllability was obtained. Table 2 shows the charge amount.

When an image was formed using a commercially available copying machine [manufactured by SF-8300 Sharp] using the positively chargeable toner, the toner had stable chargeability in continuous copying of 20,000 sheets and was free from fog. A black image with good fine line reproducibility was obtained.

(Example 7) The positively chargeable toner of the present invention
Styrene / acrylic copolymer resin [ESLEK P-598 (trade name) manufactured by Sekisui Chemical Co., Ltd.] 100 parts carbon black [MA-100 (trade name) manufactured by Mitsubishi Chemical Corporation] 6 parts Compound Example (22) 2 parts The above composition was treated in the same manner as in Example 1 to give a particle size of 10.46.
A black toner having a charge control agent concentration of 0.86% by weight on the surface of the positively chargeable toner was obtained, and a developer was prepared.

The blow-off charge of the developer was measured using a blow-off powder charge measuring device manufactured by Toshiba Chemical Corporation. As a result, excellent charge controllability was obtained. Table 2 shows the charge amount.

Further, a commercially available copying machine [S
F-8300 manufactured by Sharp Corporation], a black image having stable chargeability, no fog, and good fine line reproducibility was obtained in 20,000 continuous copies.

Example 8 Using the toner of the present invention as a two-component developer, a styrene / acrylic copolymer resin [ESLEC P-598 (trade name) manufactured by Sekisui Chemical Co., Ltd.] 100 parts carbon black [MA -100 (trade name, manufactured by Mitsubishi Kasei Co., Ltd.) 5 parts Compound example (25) 2 parts The above composition was treated in the same manner as in Example 1, and the particle size was 9.770.
A black toner having a charge control agent concentration of 0.85% by weight on the surface of the positively chargeable toner having a thickness of μm was obtained to prepare a developer.

When the blow-off charge of the developer was measured using a blow-off powder charge measuring device manufactured by Toshiba Chemical Corporation, excellent charge controllability was obtained. Table 2 shows the charge amount.

Further, when an image was formed using a commercially available copying machine [manufactured by SF-8300 Sharp] using the positively chargeable toner, the toner had stable chargeability in continuous copying of 20,000 sheets and was free from fog. A black image with good fine line reproducibility was obtained.

(Example 9) The positively chargeable toner of the present invention
Styrene / acrylic copolymer resin [ESLEK P-598 (trade name) manufactured by Sekisui Chemical Co., Ltd.] 100 parts Copper phthalocyanine pigment 5 parts Compound example (5) 2 parts The above formulation was treated as in Example 1 to give a particle size of 10.22.
A blue toner having a charge control agent concentration of 0.86% by weight on the surface of the positively chargeable toner having a thickness of μm was obtained to prepare a developer.

When the blow-off charge of the developer was measured using a blow-off powder charge measuring device manufactured by Toshiba Chemical Corporation, excellent charge controllability was obtained. Table 2 shows the charge amount.

When an image was formed using a commercially available copying machine [manufactured by SF-8300 Sharp] using the positively chargeable toner, the toner had stable chargeability in continuous copying of 20,000 sheets and was free from fog. A blue image with good fine line reproducibility was obtained.

(Example 10) A styrene / acrylic copolymer resin (S-LEC P-598 (trade name) manufactured by Sekisui Chemical Co., Ltd.) using the positively chargeable toner of the present invention as a two-component developer 100 parts carbon Black [MA-100 (trade name) manufactured by Mitsubishi Chemical Corporation] ... 5 parts Compound example (2) ... 2 parts The above composition was treated in the same manner as in Example 1 to obtain a particle size of 9.528.
A black toner having a charge control agent concentration of 0.98% by weight on the surface of the positively chargeable toner having a thickness of μm was obtained to prepare a developer.

When the blow-off charge amount of the developer was measured using a blow-off powder charge amount measuring device manufactured by Toshiba Chemical Corporation, excellent charge controllability was obtained. Table 2 shows the charge amount.

Further, when an image was formed using a commercially available copying machine [manufactured by SF-8300 Sharp] using the positively chargeable toner, the toner had stable chargeability in continuous copying of 20,000 sheets and was free from fog. A black image with good fine line reproducibility was obtained.

(Example 11) A styrene / acrylic copolymer resin (S-LEC P-598 (trade name) manufactured by Sekisui Chemical Co., Ltd.) using the positively chargeable toner of the present invention as a two-component developer: 100 parts carbon Black [MA-100 (trade name) manufactured by Mitsubishi Chemical Corporation] ... 5 parts Compound example (2) ... 1 part Compound example (5) ... 1 part The above mixture was treated in the same manner as in Example 1. The particle size is 10.15
A black toner having a μm and a charge control agent concentration of 1.12% by weight on the toner surface was obtained, and a developer was prepared.

The blow-off charge of the developer was measured using a blow-off powder charge measuring device manufactured by Toshiba Chemical Corporation. As a result, excellent charge controllability was obtained. Table 2 shows the charge amount.

Further, when an image was formed using a commercially available copying machine [manufactured by SF-8300 Sharp] using the positively chargeable toner, the toner had stable chargeability in continuous copying of 20,000 sheets and was free from fog. A black image with good fine line reproducibility was obtained.

(Comparative Example 1) As a two-component developer, a styrene / acrylic copolymer resin [ESLEC P-598 (trade name) manufactured by Sekisui Chemical Co., Ltd.] 100 parts carbon black [MA-100 (trade name)] 5 parts cetylpyridinium chloride ... 2 parts The above composition was treated in the same manner as in Example 1 to obtain a particle size of 10.25.
A black toner having a charge control agent concentration of 1.13% by weight on the surface of the positively chargeable toner was obtained by preparing a developer.

When the blow-off charge of the developer was measured using a blow-off powder charge measuring device manufactured by Toshiba Chemical Corporation, the charge gradually decreased, and stable charge controllability was not obtained. Table 3 shows the charge amount.

Further, when an image was formed using a commercially available copying machine [manufactured by SF-8300 Sharp] using the positively chargeable toner, the charge amount was reduced during continuous copying of 20,000 sheets, and fog occurred. The thin line reproducibility of the black image was poor.

(Comparative Example 2) As a two-component developer, a styrene / acrylic copolymer resin [ESLEC P-598 (trade name) manufactured by Sekisui Chemical Co., Ltd.] 100 parts carbon black [MA-100 (trade name)] 5 parts dipentyldimethylammonium chloride ... 2 parts The above composition was treated in the same manner as in Example 1 to obtain a particle size of 9.759.
A black positively chargeable toner having a charge control agent concentration of 1.03% by weight on the surface of the positively chargeable toner having a thickness of μm was obtained, and a developer was prepared.

When the blow-off charge of the developer was measured using a blow-off powder charge measuring device manufactured by Toshiba Chemical Co., Ltd., stable charge controllability was not obtained. Table 3 shows the charge amount.

Further, when an image was formed using a commercially available copying machine [manufactured by SF-8300 Sharp] using the positively chargeable toner, the charge amount was reduced during continuous copying of 20,000 sheets, and fogging occurred. The thin line reproducibility of the black image was poor.

(Comparative Example 3) As a two-component developer, a styrene / acrylic copolymer resin [ESLEC P-598 (trade name) manufactured by Sekisui Chemical Co., Ltd.] 100 parts carbon black [MA-100 (trade name)] 5 parts Compound Example (25) ... 12 parts The above compound was treated in the same manner as in Example 1 to obtain a particle size of 9.770.
A black toner having a charge control agent concentration of 3.92% by weight on the surface of the positively chargeable toner was obtained, and a developer was prepared.

When the blow-off charge of this developer was measured using a blow-off powder charge measuring device manufactured by Toshiba Chemical Corporation, stable charge controllability was not obtained. Table 3 shows the charge amount.

When an image was formed using a commercially available copying machine [manufactured by SF-8300 Sharp] using the positively chargeable toner, the charge amount was reduced during continuous copying of 20,000 sheets, and fogging occurred. The thin line reproducibility of the black image was poor.

(Comparative Example 4) As a two-component developer, a styrene / acrylic copolymer resin [ESLEC P-598 (trade name) manufactured by Sekisui Chemical Co., Ltd.] 100 parts carbon black [MA-100 (trade name)] 5 parts Compound Example (25) ... 1 part The above compound was treated in the same manner as in Example 1 to obtain a particle size of 9.770.
A black toner having a charge control agent concentration of 0.48% by weight on the surface of the positively chargeable toner was obtained by preparing a developer.

When the blow-off charge of the developer was measured using a blow-off powder charge measuring device manufactured by Toshiba Chemical Corporation, stable charge controllability was not obtained. Table 3 shows the charge amount.

Further, when an image was formed using a commercially available copying machine [manufactured by SF-8300 Sharp] using the positively chargeable toner, the charge amount was reduced during continuous copying of 20,000 sheets, and fogging occurred. The thin line reproducibility of the black image was poor.

Tables 2 and 3 show the characteristics of the positively chargeable toners of the present invention and the comparative examples. The horizontal frames in Tables 2 and 3 show the amount of charge depending on the stirring time.

[0160]

[Table 2]

[0161]

[Table 3]

[0162]

EFFECT OF THE INVENTION The salt forming compound of the present invention has a chargeability, heat resistance,
Because of its excellent moisture resistance and excellent dispersibility in resin, a positively chargeable toner containing the same has stable charging performance against changes in temperature and humidity. Further, the contamination of the frictional charging member such as the carrier is small, and the stable positive charging performance is maintained for a long time.

Furthermore, when a specific compound among these salt-forming compounds is used, crystallization during the synthesis is facilitated, or those having a small light absorption in the visible light region have no discoloration even in the production process and are stable in color tone. Quality can be maintained.

Claims (6)

[Claims] 1. A positively chargeable toner containing at least a colorant, a thermoplastic resin, and a charge control agent, wherein the charge control agent is a salt-forming compound comprising a reaction product represented by the following general formulas [a] and [b]: A positively chargeable toner comprising at least one kind of General formula [a] nA ⁺ General formula [b] (In the formula, A ⁺ represents a cation containing a quaternary nitrogen atom or a tertiary sulfur atom. B represents a monovalent anion, hydrogen, a hydroxyl group, or a lower alkyl group. In addition, n is an integer of 1 or 2. is there.) 2. A positively chargeable toner containing at least a colorant, a thermoplastic resin, and a charge control agent, wherein the charge control agent contains at least one or more salt-forming compounds represented by the following general formula [I]. Positively chargeable toner. General formula [I] (In the formula, A ⁺ represents a cation containing a quaternary nitrogen atom or a tertiary sulfur atom.) 3. A positively chargeable toner containing at least a colorant, a thermoplastic resin, and a charge control agent, wherein the charge control agent contains at least one or more salt-forming compounds represented by the following general formula [II]. Positively chargeable toner. General formula [II] (In the formula, R _{1 to} R _{4 each} represent an alkyl group, an aryl group, or an aralkyl group. These may include a substituent.) 4. A positively chargeable toner containing at least a colorant, a thermoplastic resin and a charge control agent, wherein the charge control agent contains at least one or more salt forming compounds represented by the following general formula [III]. Positively chargeable toner. General formula [III] (In the formula, A ⁺ represents a cation containing a quaternary nitrogen atom or a tertiary sulfur atom.) 5. The method according to claim 1, wherein the charge control agent is a thermoplastic resin.
The positively chargeable toner according to any one of claims 1 to 4, wherein 0.1 to 10 parts by weight is added to 0 part by weight. 6. The method according to claim 1, wherein the ratio of the charge control agent present on the surface of the positively chargeable toner is in the range of 0.5 to 1.5% by weight. The positively chargeable toner as described in the above.