JP2003215849A - Electrostatic charge image developing toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an excellent toner with durability and stability which is free from increase in contamination of a white base (fog) or decrease in image density when the toner is repeatedly used in a copying machine or a printer, which does not cause increase in the fog with time or scattering in a machine even when the toner is left to stand in a high temperature environment. <P>SOLUTION: In the electrostatic charge image developing toner containing at least a binder resin, a coloring agent and a charge controlling agent, the charge controlling agent is a salt-forming compound expressed by general formula (1). In formula (1), each of R<SB>1</SB>to R<SB>8</SB>represents -H, -OH, -NH<SB>2</SB>or -SO<SB>3</SB>, including one -NH<SB>2</SB>and one -SO<SB>3</SB>as essential components. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic copying machine in which an image is formed by utilizing an electrophotographic method, an electrostatic recording method, etc.
The present invention relates to an electrostatic charge image developing toner used for developing an electrostatic latent image in a laser beam printer or the like.

[0002]

2. Description of the Related Art Conventionally, as a method of developing an electrostatic latent image formed on an electrostatic charge image bearing member such as an electrophotographic photosensitive member or an electrostatic recording member, fine toner is generally classified into an electrically insulating liquid. There are known two methods, a method using a dispersed liquid developer (wet developing method) and a method using a toner in which a colorant or magnetic powder is dispersed in a binder resin (dry developing method). In the dry development method, a method of using a two-component developer containing carrier particles and a toner and a method of using a one-component developer containing only a toner are known.

The electrostatic image developing toner used in these dry developing methods usually uses a styrene resin or a polyester resin as a binder resin, and a colorant such as a dye or a pigment is kneaded and cooled. After that, it is manufactured through a crushing and classification process. The particle size of the toner for developing an electrostatic charge image is usually about 1 to 30 μm. In the case of magnetic toner, magnetic powder such as magnetite is further used.
Further, as the carrier particles used in the two-component developer, glass beads, iron powder, magnetite, etc., which are optionally coated with a resin, are used.

The electrostatic image developing toner as described above is required to hold positive or negative charges depending on the polarity of the electrostatic latent image to be developed. In order to retain the electric charge in the electrostatic image developing toner, the triboelectrification property of the toner components such as the binder resin and the colorant can be utilized, but this alone usually has a small charge amount and a stable polarity. Therefore, the image obtained by the development is easily fogged and becomes unclear. Therefore, a substance called a charge control agent is generally added to the toner in order to impart desired charging characteristics to the toner.

Typical examples of conventional charge control agents include:
For imparting a positive charging property to the toner, for example, a basic dye such as a triarylmethane dye, a nigrosine dye (Japanese Patent Publication No. 48-25669), and a quaternary ammonium salt (Japanese Patent Laid-Open No. 57-119364). Gazette), organotin oxide (Japanese Patent Publication No. 57-29704), and polymers having an amino group, such as electron donating substances, which impart negative chargeability to the toner, such as metal complexes of monoazo dyes and aromatic hydroxy compounds. Examples thereof include metal-containing dyes such as carboxylic acid metal compounds and chromium-containing organic dyes (copper phthalocyanine green, chromium-containing monoazo dyes).

In recent years, as a photoreceptor for an electrophotographic copying machine or a printer, a photoreceptor using an organic photoreceptor has become popular, and a positively chargeable toner is required as a developer for a copying machine using the organic photoreceptor. Has been. However, many of the positively chargeable charge control agents used for producing this positively chargeable toner are hydrophilic, and the charge amount is likely to decrease under high humidity conditions, while the charge amount decreases under high humidity conditions. Many of them do not have a problem that the charge amount becomes unnecessarily high under low humidity. In addition, there are many cases where the positively chargeable charge control agent suffers from deterioration due to heat when the toner is left at a high temperature for a long period of time, resulting in increased fog and scattering in the machine. For example, the Nigrosine dye is
Although it has high charging performance, the amount of charge on the toner becomes excessively high due to its very strong positive charging property, and the image density may decrease as the number of copies increases. Conditions required as a charge control agent It's hard to get anything that satisfies you. The quaternary ammonium salt is
Due to its low charge imparting ability, fog may increase and scattering may occur in the machine as the number of copies increases under high temperature and high humidity. Furthermore, deterioration often occurs when left at high temperature.

Further, triarylmethane type dyes such as methyl violet, crystal violet, crystal violet base and methyl violet base are
Although it exhibits excellent positive chargeability, it often has problems in water resistance or oil resistance and is practically difficult to use as a toner. If the water resistance is poor, the environmental stability will be poor, and the charge amount will decrease, especially in high humidity, causing fog to increase and scattering in the machine. Further, these dyes are eluted from the toner and cause image contamination. On the other hand, if the oil resistance is poor,
When using silicone oil etc. in the fixing unit,
When the toner melts, these dyes elute and cause color contamination of the fixing unit and the image.

[0008]

As described above, the triarylmethane dyes are relatively excellent positive charge control agents, but they also have various problems. Solving these problems, it is excellent in water resistance and oil resistance, has a moderately high amount of charge and is stable, has little dependency on temperature and humidity during development, and does not deteriorate toner properties due to being left at high temperature and high humidity. There is a demand for a positively chargeable charge control agent having excellent dispersibility in respect to the toner, excellent development characteristics and excellent durability, and a positively chargeable toner containing the same.

An object of the present invention is to provide a positively chargeable electrostatic image developing toner having excellent characteristics which does not have the above problems, that is, friction between a toner and a carrier and between a toner and a toner carrier such as a developing sleeve. It is an object of the present invention to provide a toner for developing an electrostatic charge image having a high charge amount, which is stable, is not affected by temperature and humidity, and can form a stable toner image, which has a positive chargeability.

Another object of the present invention is to provide a toner for developing a positively chargeable electrostatic image, which has a stable triboelectric charge amount even when the number of copies increases and does not cause fog or toner scattering in the machine. Is.

Another object of the present invention is to provide a positively chargeable electrostatic charge image developing toner capable of forming a clear image without fog in which a charge control agent is uniformly dispersed in the toner. That is.

A further object of the present invention is to provide a positively chargeable electrostatic image developing toner which does not deteriorate in toner characteristics due to thermal stress during toner storage.

[0013]

Means for Solving the Problems As a result of intensive studies, the present inventors have achieved the above object by using a salt-forming compound composed of methyl violet and an organic sulfonic acid having a specific structure as a charge control agent. The inventors of the present invention have found that they can do so and have reached the present invention.

That is, the first invention is a toner for developing an electrostatic charge image containing at least a binder resin, a colorant and a charge control agent, wherein the charge control agent is a salt-forming compound represented by the following general formula (1). The present invention relates to a toner for developing an electrostatic charge image, which comprises:

[Chemical 3] (In the formula, R _{1 to} R ₈ are —H, —OH, —NH ₂ or —S.
One of O ₃ and one essential component
Containing NH _2, 1 single -SO _3. )

The second invention is characterized in that the content of the salt-forming compound represented by the general formula (1) is 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The toner for developing an electrostatic charge image according to the first aspect of the present invention.

In a third aspect of the invention, the volume average particle size of the salt-forming compound represented by the above general formula (1) is 0.5 to 40.
The toner for developing an electrostatic charge image according to the first or second aspect of the invention is characterized by having a thickness of μm.

A fourth invention is the electrostatic image developing toner according to any one of the first to third inventions, wherein the toner has a positive charging property.

The fifth invention is the electrostatic charge image developing toner according to any one of the first to fourth inventions, characterized in that the toner is a dry non-magnetic toner.

A sixth invention is the electrostatic image developing toner according to any one of the first to fourth inventions, wherein the toner is a dry magnetic toner.

A seventh invention is a toner for developing an electrostatic charge image, which contains a salt-forming compound obtained by reacting methyl violet with an organic sulfonic acid represented by the general formula (2). is there.

[Chemical 4] (In the formula, R _{1 to} R ₈ are —H, —OH, —NH ₂ or —S.
It is any of O ₃ H and contains one —NH ₂ and one —SO ₃ H as essential components. )

The present invention will be described in more detail below. Good as a positive charge control agent for electrostatic image developing toner,
The salt-forming compound of the present invention is a salt-forming compound represented by the general formula (1) obtained by reacting methyl violet represented by the structural formula (3) with an organic sulfonic acid represented by the general formula (2). It is a compound.

[Chemical 5] Specifically, the organic sulfonic acid represented by the general formula (2) is dissolved in a 7 to 15 mol% alkali hydroxide solution and sufficiently mixed and stirred to obtain a sodium salt of the organic sulfonic acid. At this time, the reaction between the organic sulfonic acid and sodium hydroxide is performed in equimolar amounts. This organic sulfonic acid sodium salt aqueous solution is heated to 70 to 90 ° C., and then methyl violet (CI Basic Violet 1) is dropped little by little. At this time, the reaction of the organic sulfonic acid sodium salt and methyl violet is performed in equimolar amounts. Methyl violet may be dissolved in water and used as an aqueous solution. After dropping methyl violet, 70
Stir at 40 ° C to 90 ° C for 40 to 60 minutes to carry out a sufficient reaction. To confirm the end point of the reaction, it can be judged that the salt-forming compound was obtained by dripping the reaction solution onto the filter paper and observing the point where the bleeding disappeared as the end point. After cooling to room temperature with stirring,
Filter with suction and wash with water. After washing with water, the salt-forming compound remaining on the filter paper is dried to remove water with a drier to obtain a salt-forming compound of methyl violet and an organic sulfonic acid.

In designing the salt-forming compound of the present invention, it is necessary to select it in consideration of the properties of the above-mentioned organic sulfonic acid as a raw material. That is, the amino group in the organic sulfonic acid is essential for maintaining and stabilizing the positive chargeability of the salt-forming compound. Further, in combination with the amino group in methyl violet, good positive chargeability can be obtained.
The hydroxyl group in the organic sulfonic acid has the effect of lowering the resistance of the salt-forming compound. A salt-forming compound having a large molecular weight tends to have strong lipophilicity, excellent compatibility, wettability, and good dispersibility in the binder resin and good distributability. On the other hand, when the salt forming compound has a small molecular weight, the proportion of amino groups in the molecule is high, and the positive charging property tends to be stable.

Further, it is essential that the charge control agent has good water resistance and oil resistance. If the water resistance is poor, the charge control agent will elute from the toner under high humidity, making it impossible to impart good charge to the toner. Further, the image may be contaminated due to elution. On the other hand, if the oil resistance is poor, the toner will elute in the fixing step using silicone oil, which will contaminate the fixing member and also the copy image. For water resistance, 50c
It can be confirmed by adding 500 mg of the charge control agent sample to the water of c and visually confirming the solubility. The oil resistance can be confirmed by adding 500 mg of the charge control agent sample to 50 cc of silicone oil and visually confirming the solubility. The water resistance and oil resistance of the compound of the present invention were confirmed by these methods.

Examples of the organic sulfonic acid which can be used in the present invention include 1-naphthylamine-2-sulfonic acid, 2-naphthylamine-1-sulfonic acid, 1-naphthylamine-4-sulfonic acid and 1-naphthylamine-5.
-Sulfonic acid, 1-naphthylamine-6-sulfonic acid,
1-naphthylamine-7-sulfonic acid, 1-naphthylamine-8-sulfonic acid, 2-naphthylamine-5-sulfonic acid, 2-naphthylamine-6-sulfonic acid, 2-amino-5-naphthol-7-sulfonic acid, 2 -Amino-
8-naphthol-6-sulfonic acid or the like can be used. In particular, 1-naphthylamine-2 is particularly preferable as the one satisfying properties such as strong positive chargeability, good dispersibility in the binder resin, good dispersibility, water resistance, and oil resistance.
-Sulfonic acid, 2-naphthylamine-1-sulfonic acid,
1-naphthylamine-4-sulfonic acid, 1-naphthylamine-5-sulfonic acid, 2-amino-5-naphthol-
It is preferable to use 7-sulfonic acid or 2-amino-8-naphthol-6-sulfonic acid.

Methyl violet has a good positive charge property, but has poor water resistance and oil resistance and is difficult to use as a charge control agent for toner. However, water resistance and oil resistance can be improved by forming a salt-forming compound using an organic sulfonic acid. The salt-forming compound of the present invention obtained here is excellent in both water resistance and oil resistance and has good positive chargeability.

The compound of the present invention is ground by a grinder,
It can be used more effectively by adjusting to a desired particle size distribution. As the type of crusher, an airflow collision type crusher such as a jet mill, a turbo mill, KTM, MV
A mechanical impact type crusher such as M is used. A good particle size distribution for the charge control agent of the present invention is 0.5 in terms of volume average particle size.
˜40 μm, more preferably 1-20 μm
Good to be. If the particles having a particle size larger than 40 μm are used, it becomes difficult to disperse the charge control agent in the binder resin and it becomes impossible to disperse the charge control agent in the toner. In addition, the content of the charge control agent per toner particle becomes uneven, which causes an increase in fog and scattering in the machine. On the other hand, when the particles having a particle size smaller than 0.5 μm are used, although the dispersion in the binder resin is good, the specific surface area of the charge control agent becomes large and the toner is excessively charged. The charge amount increases and the image density decreases.

The amount of the compound of the present invention used in the toner for developing an electrostatic image varies depending on the kind of the binder resin used,
Usually, 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, and more preferably 0.
8 to 3 parts by weight.

In the electrostatic image developing toner of the present invention, as the charge control agent, other charge control agents may be used in addition to the compound of the present invention for the purpose of finely adjusting the charge control of the toner. . As such a charge control agent, any known charge control agent which has been known to be capable of imparting a positive chargeability to a toner may be used, and among them, a nigrosine dye or Quaternary ammonium salts are preferred.

As the constituent components of the toner for developing an electrostatic image of the present invention, a binder resin and a colorant, which are known materials constituting the toner, are used in addition to the charge control agent of the present invention. When a magnetic toner is obtained, a magnetic powder is further used. When a magnetic powder is used, the magnetic powder may be used as a coloring agent. Therefore, in the present invention, the colorant also includes magnetic powder. If necessary, a releasing agent, a lubricant, a fluidity improving agent, an abrasive, a conductivity-imparting agent, an image peeling preventing agent, etc. are internally or externally added to the electrostatic image developing toner.

Specific examples of the binder resin used in the toner of the present invention include styrene-based polymers such as polystyrene, poly-p-chlorostyrene, and homopolymers of substituted styrenes such as polyvinyltoluene. Styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylic copolymer, styrene-α-chloromethacrylic acid methyl ester Copolymer, styrene-vinyl methyl ether copolymer,
Styrene-vinyl ethyl ether copolymer, styrene-
Vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene diethylaminoethyl acrylate copolymer, styrene- Styrene-based copolymers such as butyl acrylate-diethylaminoethyl methacrylate copolymer, cross-linked styrene-based copolymers, etc .; polyester resins such as aliphatic dicarboxylic acids, aromatic dicarboxylic acids, aromatic dialcohols, diphenols Polyester resin having a monomer selected from the structural units as a structural unit, cross-linked polyester resin, etc .; other polyvinyl chloride, phenol resin, modified phenol resin, malein resin, rosin modified maleic resin, polyvinyl acetate Silicone resins, polyurethane resins, polyamide resins, epoxy resins, polyvinyl butyral, rosin, modified rosin, terpene resin, xylene resin, aliphatic or aliphatic hydrocarbon resins, and petroleum resins.

Examples of the acrylic monomer used in the styrene / acrylic copolymer include acrylic acid and methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate. , 2-ethylhexyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate,
Examples thereof include (meth) acrylic acid esters such as butyl methacrylate and octyl methacrylate, and examples of monomers that can be used with these include acrylonitrile, methacrylonitrile, acrylamide, maleic acid, and maleic acid such as butyl maleate. Acid half ester or diester, vinyl acetate, vinyl chloride,
Examples thereof include vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether and vinyl butyl ether, and vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl hexyl ketone.

As the cross-linking agent used for producing the above-mentioned cross-linked styrenic polymer, compounds mainly having two or more unsaturated bonds can be mentioned, and specific examples thereof include divinylbenzene and divinyl. Aromatic divinyl compounds such as naphthalene; Carboxylic esters having two or more unsaturated bonds such as ethylene glycol diacrylate and ethylene glycol dimethacrylate; Divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide and divinyl sulfone; and unsaturated The compounds having three or more bonds can be used alone or in combination. The cross-linking agent is used in an amount of 0.01 to 10% by weight, preferably 0.05 to 5% by weight, based on 100 parts by weight of the binder resin.

These resins can be used alone or in combination of two or more kinds. Of these resins, styrene polymers and polyester resins are preferable because they exhibit particularly excellent charging characteristics. The molecular weight distribution measured by GPC (gel permeation chromatography) has at least one peak in the region of 1x10 ³ to 5x10 ⁴ and at least one peak or shoulder in the region of 10 ⁵ or more. Such a molecular weight can be obtained by using a styrene-based copolymer that has the above-mentioned styrene-based copolymer, further two or more kinds of resins, for example, a combination of the styrene resin and a styrene-acrylic copolymer or a combination of two or more kinds of styrene-acrylic copolymers. A resin composition having a distribution is preferable from the viewpoint of toner pulverizability and fixing property.

Further, when the pressure fixing method is used, a binder resin for pressure toner can be used. Examples of such resins include polyethylene, polypropylene, polymethylene, polyurethane elastomer, ethylene-ethyl acrylate copolymer, styrene-isoprene copolymer, linear saturated polyester, paraffin and other waxes.

As the colorant that can be used in the toner for developing an electrostatic image of the present invention, any of the colorants known to be used in the production of conventional toners can be used. Examples thereof include fatty acid metal salts, various carbon blacks, phthalocyanine-based, rhodamine-based, quinacridone-based, triarylmethane-based, anthraquinone-based, azo-based and diazo-based dyes and pigments. These may be used alone or in admixture of two or more.

The magnetic powder used in the toner for developing an electrostatic charge image of the present invention is any powder such as alloys and compounds containing a ferromagnetic element, which are conventionally used in the production of magnetic toners. Good. Examples of these magnetic powders include iron oxide such as magnetite, maghemite, and ferrite, or a compound of a divalent metal and iron oxide, metals such as iron, cobalt, and nickel, or aluminum, cobalt, copper, and lead of these metals. , Magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium,
Examples thereof include powders of alloys of metals such as calcium, manganese, selenium, titanium, tungsten and vanadium, and mixtures thereof. These magnetic powders preferably have an average particle size of 0.1 to 2 μm, more preferably 0.1 to 0.5 μm. The content of the magnetic powder in the toner is
The amount is about 20 to 200 parts by mass, preferably 40 to 150 parts by mass with respect to 100 parts by mass of the thermoplastic resin. Further, the saturation magnetization of the toner is preferably 15 to 35 emu / g (measurement magnetic field: 1 kilo Oersted).

The toner of the present invention can be mixed with a carrier and used as a two-component developer. The carrier that can be used with the toner of the present invention may be any conventionally known carrier. Examples of the carrier that can be used include magnetic powder such as iron powder, ferrite powder, nickel powder, glass beads, and the like, or those whose surface is treated with a resin or the like. As the resin coating the carrier surface,
Styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, acrylic acid ester copolymer, methacrylic acid ester copolymer, fluorine-containing resin, silicone-containing resin, polyamide resin, ionomer resin, polyphenylene sulfide resin, etc. Or a mixture of these. Among these, a fluorine-containing resin and a silicone-containing resin are particularly preferable because they rarely form spent toner.

The particle size of the toner for developing an electrostatic charge image of the present invention is
Weight average particle diameter is 1 to 30 μm, preferably 3 to 15 μm
Is desirable. In particular, 12 to 60% by number of toner particles having a particle size of 5 μm or less are contained, and 8 to 12.
1 to 33% by number of toner particles having a particle size of 7 μm are contained, and 2.0% of toner particles having a particle size of 16 μm or more are contained.
It is contained in an amount of not more than 5% by weight, and the weight average particle diameter of the toner is 4 to 10
Those having a thickness of μm are more preferable from the viewpoint of developing characteristics. The particle size distribution of the toner can be measured using, for example, a Coulter counter.

In the toner of the present invention, known additives such as a releasing agent, a lubricant, a fluidity improving agent, an abrasive, a conductivity-imparting agent, an image peeling preventing agent, etc., which are used in the production of the toner, may be added, if necessary. The agent may be added internally or externally, and examples of these additives include mold release agents such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, carnauba wax, sazol wax, and paraffin wax. Wax-like substances such as, for example, are usually added to the toner in an amount of about 0.5 to 5% by weight. Further, as the lubricant, polyvinylidene fluoride, zinc stearate and the like, as the fluidity improver, silica produced by a dry method or a wet method,
Aluminum oxide, titanium oxide, silicon-aluminum co-oxide, silicon-titanium co-oxide, and those obtained by subjecting these to a hydrophobic treatment are used as polishing agents, and silicon nitride, cerium oxide, silicon carbide, strontium titanate, tungsten carbide, carbonic acid, etc. Examples of the conductivity-imparting agent include calcium and those obtained by hydrophobizing them, and carbon black, tin oxide and the like. Further, fine powder of a fluorine-containing polymer such as polyvinylidene fluoride is preferable from the viewpoints of fluidity, abradability, charge stability and the like.

In the present invention, hydrophobized silica, hydrophobized aluminum oxide, hydrophobized silicon-aluminum co-oxide or hydrophobized silicon-titanium co-oxide fine powder is excluded. It is preferably used as an additive. Examples of the hydrophobic treatment of the silica fine powder include treatment with a silane coupling agent such as silicone oil, dichlorodimethylsilane, hexamethyldisilazane, and tetramethyldisilazane. Also,
It is preferable to use positively charged silica having a positive triboelectric charge with respect to the iron powder carrier when measured by the blow-off method. In order to obtain this positively charged silica, it may be treated with a silicone oil having an organo group having at least one nitrogen atom in its side chain or a nitrogen-containing silane coupling agent. The amount of the silica fine powder subjected to the hydrophobic treatment is 0.01 per weight of the developer.
-20%, preferably 0.03-5%.

The toner according to the present invention can be manufactured by a conventionally known toner manufacturing method. Generally, the toner constituent material as described above is prepared by a ball mill,
After thoroughly mixing with a mixer such as a Henschel mixer, knead well using a heat kneader such as a heat roll kneader or a single-screw or twin-screw extruder, and after cooling and solidifying, mechanically using a crusher such as a hammer mill. It is preferable to roughly pulverize, then finely pulverize with a jet mill or the like, and then classify. After further classification, it is preferable to use the external additive after thoroughly mixing it with a mixer such as a Henschel mixer. However, the method for producing the toner is not limited to this method, and other toner constituent materials are dispersed in the binder resin solution and then spray-dried, that is, a method for producing a toner by a so-called microcapsule method, and a binder. Other methods, such as a polymerization method in which a predetermined material is mixed with a monomer forming a resin and emulsion or suspension polymerization is performed to obtain a toner, can be adopted.

The toner for developing an electrostatic charge image of the present invention is preferably developed for any method or apparatus for forming a dry toner image by utilizing conventionally known electrophotography, electrostatic recording or electrostatic printing. It can be used as a toner.

[0043]

The present invention will be described in more detail with reference to the following examples, but the embodiments of the present invention are not limited to these examples.

CHARGE CONTROL AGENT PRODUCTION EXAMPLE PRODUCTION EXAMPLE 1 6.4 g of sodium hydroxide was added to 200 g of water, heated to 80 ° C. with stirring, and then maintained at 1-
After adding 23 g of naphthylamine-2-sulfonic acid little by little, the mixture was thoroughly mixed with stirring for 1 hour. In addition, methyl violet (CI Basic Violet)
1) 40 g was added little by little at a temperature of 80 ° C., and then 6
Stir for 0 minutes. After this mixed solution was dropped on a filter paper to confirm that the bleeding had disappeared, the mixture was allowed to cool to room temperature and suction filtered. After washing with water, the salt-forming compound remaining on the filter paper was dried to remove water and dried to obtain 49.5 g of a salt-forming compound of methyl violet and 1-naphthylamine-2-sulfonic acid. Further, it was pulverized by a pulverizer (jet mill) to obtain a charge control agent 1 having a volume average particle diameter of 7.4 μm.

[Chemical 6]

Production Example 2 A charge control agent 2 having an average particle size of 7.5 μm was prepared in the same manner as in Production Example 1 except that 2-naphthylamine-1-sulfonic acid was used instead of 1-naphthylamine-2-sulfonic acid.
Got

[Chemical 7]

Production Example 3 A charge control agent 3 having an average particle size of 7.5 μm was prepared in the same manner as in Production Example 1 except that 1-naphthylamine-4-sulfonic acid was used instead of 1-naphthylamine-2-sulfonic acid.
Got

[Chemical 8]

Production Example 4 A charge control agent 4 having an average particle size of 7.6 μm was prepared in the same manner as in Production Example 1 except that 1-naphthylamine-5-sulfonic acid was used instead of 1-naphthylamine-2-sulfonic acid.
Got

[Chemical 9]

Production Example 5 A charge control agent 5 having an average particle size of 7.4 μm was prepared in the same manner as in Production Example 1 except that 2-naphthylamine-5-sulfonic acid was used instead of 1-naphthylamine-2-sulfonic acid.
Got

[Chemical 10]

Production Example 6 Charge control with an average particle size of 7.4 μm was performed in the same manner as in Production Example 1 except that 2-amino-5-naphthol-7-sulfonic acid was used instead of 1-naphthylamine-2-sulfonic acid. Agent 6 was obtained.

[Chemical 11]

Production Example 7 Charge control with an average particle size of 7.5 μm was carried out in the same manner as in Production Example 1 except that 2-amino-8-naphthol-6-sulfonic acid was used instead of 1-naphthylamine-2-sulfonic acid. Agent 7 was obtained.

[Chemical 12]

Comparative Production Example 1 A charge control agent 8 having an average particle size of 7.6 μm was prepared in the same manner as in Production Example 1 except that 1-naphthol-4-sulfonic acid was used instead of 1-naphthylamine-2-sulfonic acid. Obtained.

[Chemical 13]

[0052]

[Table 1]

Example 1 Styrene-n-butyl acrylate copolymer 87.5 parts by weight carbon black 8 parts by weight Charge control agent 12 parts by weight Polypropylene wax 2 parts by weight Polyethylene wax 0.5 parts by weight The above materials were mixed with a Henschel mixer. After uniformly mixing, the mixture was put into a twin-screw heating kneader, kneaded, and extruded was cooled at room temperature and coarsely crushed with a hammer mill to obtain chips.
Then, this was finely pulverized with a turbo mill pulverizer, introduced into a classifier, and a portion having an average particle size of 11.6 μm was taken out to obtain a fine powder for toner. Next, to 100 parts by weight of this toner fine powder, 0.3 parts by weight of positively chargeable hydrophobic silica fine powder and 0.4 parts by weight of tungsten carbide fine powder were added and mixed by a Henschel mixer to obtain positively chargeable property. A non-magnetic toner was obtained. 4 parts of the obtained toner and a carrier 1 coated with a silicone resin having an average particle size of 100 μm
00 parts were mixed with a ball mill to prepare a developer. Next, using this toner and developer, a commercially available copying machine F
P7735 (manufactured by Matsushita Electric Transmission Co., Ltd.) allows high temperature and high humidity (30
A live-copy test was conducted in an environment of 85 ° C. and 85% RH. At this time, the toner was heated in a dryer at 50 ° C. for 72 hours in order to facilitate confirmation of deterioration due to heating. When the obtained toner and developer were used, fogging was small even after actual copying of 50,000 sheets, the image density was stable, and neither toner scattering in the machine nor image stain was observed. The image densities at the initial copy and 50,000 copies were 1.37 and 1.36, respectively, and the fog at the initial copy and 50,000 copies was 0.6, respectively.
And 0.4.

The image density is measured by using a Macbeth photometer and may be 1.35 or more. The fogging was performed by measuring the reflectance with a photo bolt. A value of 1.2% or less is a good value. The toner scattering inside the machine was performed by confirming whether the scattered toner was present on the transfer charger of the copying machine. When the toner scattering is seen on the transfer charger, the image stain is generated accordingly.

Examples 2 to 7 and Comparative Examples 1 to 3 Instead of using the charge control agent 1 used in Example 1, Table 2
The same evaluation as in Example 1 was carried out except that the charge control agent described in 1. was used. The results are shown in Table 3.

[0056]

[Table 2]

Example 8 Styrene-n-butyl acrylate copolymer 55.5 parts by weight Magnetic iron oxide 40 parts by weight Charge control agent 12 2 parts by weight Polypropylene wax 2 parts by weight Paraffin wax 0.5 parts by weight are mixed with a Henschel mixer. After that, put into a twin-screw heating kneader, knead, and cool the extruded one at room temperature,
Coarse crushing with a hammer mill gave chips. Then, this is pulverized with a turbo mill pulverizer and introduced into a classifier to obtain 10μ.
A portion having an average particle size in m was taken out as a fine powder for toner. To 100 parts by weight of this toner fine powder, 0.25 parts by weight of silica hydrophobized with silicone oil was added and mixed with a Henschel mixer to obtain a positively chargeable magnetic toner, and then this toner was heated with time. I examined the changes.
The test of heating aging was performed by placing the toner in a dryer at 50 ° C for 7
After leaving it for 2 hours to accelerate the heating deterioration, it was removed by using a commercially available copying machine (copying machine NP4145 manufactured by Canon Inc.).
It was based on continuous continuous shooting of 50,000 sheets at an environmental condition of 50 ° C. The image densities at the initial copying and 50,000 copying were 1.40 and 1.39 respectively, and the fog at the initial copying and 50,000 copying were 0.5 and 0.6, respectively, which were not particularly changed. Furthermore, there was no scattering of toner particles inside the machine after copying 50,000 sheets, and there was no stain on the obtained image.

Examples 9 to 14 and Comparative Examples 4 to 6 Instead of using the charge control agent 1 used in Example 8, Table 3
The same evaluation as in Example 8 was carried out except that the charge control agent described in 1. was used. The results are shown in Table 3.

[0059]

[Table 3]

[0060]

As described above, by using the salt-forming compound of the present invention as a charge control agent for a toner for developing an electrostatic charge image, a toner for developing an electrostatic charge image in which a charge control agent is uniformly dispersed is obtained. This toner has a good image density from the initial stage and can obtain a fog-free copy image, and the image density does not decrease even when a large number of copies are piled up. The charge image developing toner does not change with time due to heating, and it is possible to obtain a good toner that does not change in characteristics due to heat stress during storage of the toner before or after purchase, or during transportation.

Claims (7)

[Claims] 1. A toner for developing an electrostatic charge image containing at least a binder resin, a colorant and a charge control agent, which contains a salt-forming compound represented by the following general formula (1) as a charge control agent. A toner for developing an electrostatic charge image, characterized by: [Chemical 1] (In the formula, R _{1 to} R ₈ are —H, —OH, —NH ₂ or —S.
One of O ₃ and one essential component
Containing NH _2, 1 single -SO _3. ) 2. The content of the salt-forming compound represented by the general formula (1) is 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. Toner for developing electrostatic images. 3. The toner for developing an electrostatic charge image according to claim 1, wherein the salt-forming compound represented by the general formula (1) has a volume average particle size of 0.5 to 40 μm. . 4. The toner for developing an electrostatic charge image according to claim 1, wherein the toner has a positive charging property. 5. The toner for developing an electrostatic charge image according to claim 1, wherein the toner is a dry non-magnetic toner. 6. The toner for developing an electrostatic charge image according to claim 1, wherein the toner is a dry magnetic toner. 7. An electrostatic charge image developing toner containing a salt-forming compound formed by reacting methyl violet with an organic sulfonic acid represented by the general formula (2). [Chemical 2] (In the formula, R _{1 to} R ₈ are —H, —OH, —NH ₂ or —S.
It is any of O ₃ H and contains one —NH ₂ and one —SO ₃ H as essential components. )