JPS61217055A - Electrostatic charge image developing toner - Google Patents

Abstract

PURPOSE:To stabilize triboelectrification amt., to render its distribution sharp and uniform, to optimize a development system, and to obtain a sharp image without being affected by temp. and humidity by incorporating a specified compd. as an electrostatic charge controller in a binder resin. CONSTITUTION:A toner contains 2-aminobenzoimidazols stable against heat and time lapse, small is hygroscopicity and superior in charge control performance represented by the formula shown on the right in which R1, R2 are each H, alkyl, aryl, aralkyl, or alkoxy. The use of such a charge controller permits triboelectrification amt. between toner particles themselves, between toner particles and carrier particles, and between those and a toner carrying body to be stabilized, its distribution to be made sharp and uniform, and this amt. to be adapted to a development system, accordingly development and transfer to be enhanced in fidelity to a latent image, the toner to be not agglomerated and prevented for a long period from agglomeration, a sharp chromatic color image to be obtained, fixability to be improved, and trouble in a cleaning step, such as the stain and the damage of the latent image, to be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a new toner for developing electrostatic images in electrophotography, electrostatic recording, electrostatic printing, and the like.

[Conventional technology]

Conventionally, as an electrophotographic method, U.S. Patent No. 2,297°69
1, Special Publication No. 42-23910, and Special Publication No. 43
Various methods are described in Japanese Patent No. 24748, etc., but in short, these methods apply a uniform electrostatic charge on a photoconductive insulating layer and irradiate the insulating layer with a light image to generate static electricity. Forms an electric latent mark, then develops and visualizes the latent image using a fine powder called toner using the technology, transfers the powder image to paper, etc. as necessary, and then fixes it by heating, pressurizing, or solvent vapor. This is what we do.

The developing methods applied to these electrophotographic methods include:
Broadly speaking, there are dry development methods and wet development methods. The former is further divided into a method using a two-component developer and a method using a -component developer.

Two-component developing methods include a magnetic brush method using an iron powder carrier, a cascade method using a bead carrier, a fur brush method using fur, etc., depending on the type of carrier for conveying the toner.

In addition, those belonging to the -component type development method include a powder cloud method in which toner particles are sprayed, and a contact development method (contact development, or (also referred to as toner development), jumping development method in which toner particles are not brought into direct contact with the electrostatic latent image surface, but are charged and flown toward the latent image surface by the electric field of the electrostatic latent image; and magnetic conductive method. There is the MagneDry method, which develops by bringing a toner into contact with the electrostatic latent image surface.

Toners used in these development methods have traditionally been fine powders in which dyes and pigments are dispersed in natural or synthetic resins.For example, colorants in binder resins such as polystyrene have been used. Particles obtained by finely pulverizing particles of about 1 to 30 jL are used as toner. As the magnetic toner, one containing magnetic particles such as magnetite is used. In the case of a system using a so-called two-component developer, the toner is usually mixed with carrier particles such as glass beads and iron powder. Further, the toner is made to hold a positive or negative charge depending on the polarity of the electrostatic latent image to be developed.

In order to make the toner hold an electric charge, it is possible to use the triboelectricity of the resin that is a component of the toner, but with this method, the toner's chargeability is small, so the image obtained by development is prone to fogging and is unclear. Become something. Therefore, in order to impart desired triboelectrification properties to toners, dyes and pigments that impart electrostatic properties, as well as charge control agents, are added.

Charge control agents known in the art today include the following:

(1) The following substances can be used to control the toner to be positively charged.

Nigrosine, azine dyes containing an alkyl group having 2 to 16 carbon atoms (Japanese Patent Publication No. 1827/1983), basic dyes (e.g. C,1,Ba5ic Yellow 2 (C,1
, 41000), C, 1, Ba5ic Yellow
3, C,1,Ba5ic Red 1 (C,I.

45180), C, 1, flasic Red 9 (
C.I. 4250G), C, I.

Ba5ic Violet 1 (C, 1, 42535
), C,L Ba5icViolet 3 (C,
1,42555), C,1,Ba5ic Viol
etlo(C,1,45170),C,1,Ba5ic
Violet 14 (C, 1°42510), C
,1,Ba5ic Blue l (ill:,1.4
2025), C, 1°Ba5ic Blue 3 (C
, 1, 51005), C, 1, Ba5ic Blue
e5 (C,1,4214G), C,1,Ba5ic
Blue 7 (C:,!

42595), C,1,Ba5ic Blue 9
(C, 1, 52015), C, I.

Ba5ic Blue 24 (C, 1, 52030)
,C,1,Ba5ic Blue25 (C,1,52
G25), C,1,Ba5ic Blue 2B
(C,1゜44Q45), C,1,Ba5ic Gre
en 1 (C, 1, 42040), C, 1, Ba5i
c Greer+ 4 (C, 1,42000), etc.), lake pigments of these basic dyes (lake-forming agents include phosphotungstic acid, phosphomolybdic acid, phosphotungsten-molybdic acid, tannic acid, lauric acid,
gallic acid, ferricyanide, ferrocyanide, etc.
), C,1,5olvent Black 3
(C.

1, 28150), Hansa Yellow GCCA, 11
880), C91, Mordant Black
11. C, 1, Pigmsnt Black l.

Gilt night, asphalt, etc.

Quaternary ammonium salt 1 For example, benzylmethyl-hexadecyl ammonium chloride, decyl-trimethylammonium chloride, organic tin compounds such as dibutyltin oxide, metal salts of higher fatty acids, inorganic fine powders such as glass, mica, zinc oxide, EDTA, Polyamine resins such as metal complexes of acetylacetone, vinyl polymers containing amine groups, and condensation polymers containing amino groups.

(2) The following substances can be used to control the negative chargeability of toner.

Special Publication No. 41-20153, No. 43-275913,
Metal complex salts of monoazo dyes described in 44-8397 and 45-28478.

Dyes and pigments such as nitrofumic acid and its salts or G, 1.14845 described in JP-A-50-133338, JP-B No. 55-42752, JP-B 58-4150
No. 8, Special Publication No. 59-7384, Special Publication No. 59-7385
Metal complexes such as Go, Cr, and 'Fe of salicylic acid, naphthoate, and guicarboxylic acid, and sulfonated copper phthalocyanine pigments, which are described in No. Styrene oligomers with nitro groups and halogens, chlorinated paraffins,
Melamine resin etc.

Many of these charge control agents are derived from dyes and pigments.
Generally, they have a complex structure, and many of them have strong coloring properties.

Recently, there are some newly proposed products that are different from these, but none have superior overall performance to dyes and pigments, and examples of dyes and pigments still being used are still unsatisfactory. Most of them are.

These are usually added to a thermoplastic resin, thermally melted and dispersed, finely pulverized, and adjusted to an appropriate particle size as required before use.

However, these dyes used as charge control agents have complex structures, inconsistent properties, and poor stability; they also decompose during thermal kneading (1) due to mechanical shock, friction, changes in temperature and humidity conditions, etc. Otherwise, it is likely to change in quality and cause a phenomenon in which charge-control amphoteric properties are reduced.

Therefore, when a toner containing these dyes as a charge control agent is used for development in a copying machine, as the number of copies increases, the charge control agent decomposes or changes in quality, which may cause deterioration of the toner during durability.

Furthermore, since it is extremely difficult to uniformly disperse these charge control agents in thermoplastic resins, they have the fatal drawback of causing a difference in the amount of frictional charge between toner particles obtained by pulverization. are doing. For this reason, various methods have been used in the past to achieve more uniform dispersion. However, unreacted fatty acids or salt dispersion products are often
It is exposed on the toner surface and contaminates the carrier or toner carrier, causing a decrease in toner fluidity, capri, and image density. Alternatively, in order to improve the dispersion of these charge control agents into the resin, a method has also been adopted in which charge control agent powder and resin powder are mechanically pulverized and mixed in advance and then hot melt-kneaded. but,
The inherent poor dispersion cannot be avoided, and the current situation is that sufficient charge uniformity has not yet been obtained for practical use.

Moreover, many of the substances generally known as charge control agents have a dark color, and therefore have the disadvantage that they cannot be incorporated into a bright, soothing color developer.

In addition, many charge control agents are hydrophilic, and due to poor dispersion in these resins, dyes are exposed on the toner surface when crushed after melt mixing, and under high humidity conditions, these charge control agents It has the disadvantage that it is difficult to obtain high-quality images because it is tree-like.

In this way, when conventional charge control agents are used in toner,
Between toner particles, between toner and carrier, between toner and toner support such as a sleeve,
This causes variations in the amount of charge generated on the surface of toner particles, which tends to cause problems such as development fog, toner scattering, and carrier contamination, and these problems become noticeable when copying is repeated many times. In effect, the result is that Cr is not suitable for copying machines.

Furthermore, under high-temperature conditions, the transfer efficiency of toner images decreases significantly, and many toners are unusable.Even at room temperature, when the toner is stored for a long time, Due to the instability of the charged charge control agent, it often undergoes deterioration and becomes unusable due to poor charging properties.

Furthermore, when conventional charge control agents are used in toner, long-term use may cause the charge control agents to adhere to the surface of the photoreceptor or promote toner adhesion, adversely affecting latent image formation (
There are many things that have a negative effect on the cleaning process of a copying machine, such as the filming phenomenon), those that cause scratches on the surface of the photoreceptor or cleaning members such as cleaning blades, and those that accelerate wear of the members.

Furthermore, when conventional charge control agents are used in toner, there are many that have a large effect on the thermal melting properties of the toner and reduce fixing properties.In particular, they worsen offset resistance at high temperatures, and when heat roll fixing There are some cases where the transfer material increases the clinging property of the roller to the roller and reduces the durability life of the roller.

As described above, conventional charge control agents have many drawbacks.
There is a strong demand in the technical field to improve these.
Although many improved techniques have been proposed so far, the reality is that no one has yet been found that is comprehensively satisfactory for practical use.

[Problem that the invention seeks to solve]

An object of the present invention is to provide a new technique for toner charge control that overcomes these drawbacks.

It is an object of the present invention to stabilize the amount of triboelectric charge between toner particles, between toner and carrier, or between toner and a toner carrier such as a sleeve in the case of -component development, and to have a sharp triboelectricity distribution. The purpose of the present invention is to provide a developer that has a uniform charge and can be controlled to have a charge amount suitable for the developing system used.

Still another object is to develop a developer that is faithful to the latent image and to perform the transfer, that is, without toner adhesion in the background area during development, without fogging or toner scattering around the edges of the latent image. High image density can be obtained,
To provide a developer with good halftone reproducibility.

Still another object is to provide a developer that maintains its initial characteristics even when the developer is used continuously over a long period of time, and that causes no toner aggregation or change in charging characteristics.

Another objective is to develop a developer that reproduces stable images that are not affected by changes in temperature and humidity, especially a developer that has high transfer efficiency and does not cause scattering or transfer dropouts during transfer at high or low humidity. On offer.

Yet another purpose! #Providing bright chromatic color developers.

Still another object is to provide a developer with excellent storage stability that maintains its initial characteristics even during long-term storage.

Still another object is to provide a developer that does not stain, abrade, or scratch the electrostatic latent image surface and is easy to clean.

Still another object is to provide a developer that has good fixing properties, particularly a developer that does not have problems such as high-temperature offset.

[Means and effects for solving the problems] The present invention is characterized in that an electrophotographic toner used for developing electrostatic images contains a 2-aminobenzimidazole represented by the general formula [1]. Toner for developing electrostatic images.

[Wherein, R1 and R2 are hydrogen atoms, halogen atoms, alkyl groups, aryl groups, aralkyl groups, alkoxy groups, aryloxy groups, aralkyloxy groups, alkylthio groups,
It represents an arylthio group, an aralkylthio group, or a nitro group, which may be the same or different, and an alkyl chain,
The aryl ring may be substituted.] The present inventors have discovered that the 2-aminobenzimidazole represented by the general formula (r) is thermally and temporally stable, has low hygroscopicity, and is suitable for developers. The present invention has been achieved by discovering that it is a high-quality charge control agent that provides a developer with excellent electrophotographic properties when it is contained in a liquid.

In the general formula [1], the substituents R1+R2 include a hydrogen atom; a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom; a methyl group, an ethyl group, a propyl group,
Alkyl groups that may be branched such as butyl, hexyl, and dodecyl; substituted alkyl groups such as methoxyethyl, ethoxyethyl, butoxyethyl, chloroethyl, and dimethylaminoethyl; phenyl, tolyl, Heptalyl groups such as butylphenyl, butoxyphenyl, and chlorphenyl groups; Heptaralkyl groups such as benzyl, phenethyl, and methylbenzyl groups; Flucoxy groups such as methoxy, ethoxy, propoxy, butoxy, and octoxy groups Aryloxy groups such as phenoxy and chlorophenoxy groups; Aralkyloxy groups such as benzyloxy, methylbenzyloxy, chlorobenzyloxy and phenethyloxy groups; Alkylthio groups such as methylthio, propylthio and hexylthio groups ; 7-arylthio groups such as phenylthio group, methylphenylthio group, ethylphenylthio group, chlorophenylthio group; aralkylthio group such as benzylthio group, chlorobenzylthio group, methylbenzylthio group; nitro group: etc. It can be mentioned as a substituent. Also, R1+R2 is 5. Position B is preferred.

Typical specific examples of 2-aminobenzimidazoles represented by general formula [1] include the following.

[Compound example]

Listen 3 N These compounds are synthesized by known methods.

Cyaminobenzimidazoles are generally synthesized by the following method.

For example, 2-aminobenzimidazole is obtained by the action of bromic cyanide on 0-phenylenediamine.

When treated with nitric acid, 2-penzimifolone is produced. The reaction of benzoyl chloride in pyridine yields 2-amino-1-benzoylbenzimidazole, and the reaction of 7-arylsrefonyl chloride in pyridine yields 2-amino-1-anolsulfonylbenzimidazole. Treatment with alkali and acidification with acetic acid yields the 7-aryl sulfonate of 2-aminobenzimidazole. The action of hydrogen peroxide in concentrated hydrochloric acid produces 2-lamino-5-chlorobenzimidazole, which is p
It can also be obtained by the reaction of -chloro-0-phenylenediamine and bromine. Esteno malonate or β-
It is condensed with a ketonic acid ester to form pinomid(1,2-α)benzimidazole (p2rimid).

(1,2-(X)benzimidazole) derivative.

Generally, the above compound has an average particle size of 10 to 0.011L.

In particular, it is preferable to prepare the toner with a particle size in the range of 5 to 0.1 g.

Methods for incorporating the above compound into the developer include a method of adding it inside the developer and a method of adding it externally. When internally added, the amount of these compounds used is determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner manufacturing method, including the dispersion method, and is uniquely limited. However, it is preferably 0.1 to 20 parts by weight (more preferably 0.1 to 20 parts by weight) per 100 parts by weight of the binder resin.
(5 to 10 parts by weight).

In addition, when externally added, 0.0 parts by weight per 100 parts by weight of resin.
1 to 10 parts by weight is preferred.

Furthermore, conventionally known charge control agents can be used in combination with the charge control agent of the present invention.

Colorants used in the present invention include carbon black, lamp black, iron black 1 ultramarine, nigrosine dye, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa Yellow G, rhodamine 8G lake, and calco oil blue.

chrome yellow, quinacridone, benzidine yellow,
Any conventionally known dyes and pigments such as rose bengal, triallylmethane dyes, monoazo dyes, disazo dyes and pigments can be used alone or in combination.

The binder resin used in the present invention is a monopolymer of styrene and its substituted products such as polystyrene, polyp-chlorostyrene, and polyvinyltoluene;
Chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene J [copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-acrylic butyl acid copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-methyl chloromethacrylate Copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer.

Styrene-vinylethyl ether copolymer, styrene-
Styrenic compounds such as vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, and styrene-maleic acid ester copolymer Copolymers: polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyurethane, polyamide, epoxy resin, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenol Examples include resins, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, and paraffin waxes, which can be used alone or in combination.

In particular, as binder resins suitable for pressure fixing, the following can be used alone or in combination.

Polyolefin (low molecular weight polyethylene, low molecular weight polypropylene, polyethylene oxide, polytetrafluoroethylene, etc.), epoxy resin, polyester resin, styrene-butadiene copolymer (monomer ratio 5-30:95-70)
, olefin copolymers (ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, ethylene-
methacrylic acid copolymer, ethylene-methacrylic acid ester copolymer, ethylene-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, ionomer resin), polyvinylpyrrolidone, methyl vinyl ether-free, hydromaleic acid copolymer, Maleic acid-modified phenolic resin, phenol-modified terpene resin.

Further, when the toner of the present invention is used as a two-component developer, it is used in combination with a carrier powder.

As carriers that can be used in the present invention, all known carriers can be used. For example, magnetic powders such as iron powder, ferrite powder, nickel powder, glass beads, etc., and carriers whose surfaces are treated with resin etc. Things can be given.

Furthermore, the toner of the present invention can contain a magnetic material and be used as a magnetic toner. The magnetic materials contained in the magnetic toner of the present invention include iron oxides such as magnetite, hematite, and ferrite, iron, cobalt, and nickel. metals such as aluminum, cobalt, copper,
Examples include alloys with metals such as lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, and vanadium, and mixtures thereof.

These ferromagnetic materials preferably have an average particle size of about 091 to 2, and are contained in the toner in an amount of about 20 to 200 parts by weight per 100 parts by weight of the resin component, particularly preferably 100 parts by weight of the resin component. The amount is about 40 to 150 parts by weight.

The toner of the present invention may also contain additives as required. Examples of additives include lubricants such as Teflon and zinc stearate, abrasives such as cerium oxide and silicon carbide, and colloidal additives. Fluidity imparting agents such as silica and aluminum oxide, anti-caking agents,
Alternatively, conductivity imparting agents such as carbon black and tin oxide, fixing aids such as low molecular weight polyethylene, etc. may also be used.

To prepare the toner for developing an electrostatic image according to the present invention, the charge control agent according to the present invention is mixed with a vinyl or non-vinyl thermoplastic resin, a pigment or dye as a coloring agent, a magnetic material as necessary, Additives, etc. are thoroughly mixed using a ball mill or other mixer, and then melted, kneaded, and kneaded using a heat kneader such as a heated roll, niegu, or extruder to make the resins mutually dissolve. A toner having an average particle size of 5 to 20 IL can be obtained by dispersing or dissolving the pigment or dye, cooling and solidifying, and then crushing and classifying.

Alternatively, by dispersing the material in a binder resin solution,
Methods such as a method of obtaining the toner by spray drying, or a method of producing a toner using a polymerization method in which the monomer to constitute the binder resin and a predetermined material are made into a mixed emulsion suspension and then polymerized to obtain the toner can be applied.

Toners produced by these methods can be used for developing to visualize electrostatic images in electrophotography, electrostatic recording, electrostatic printing, etc. by any conventionally known means, and can be used as follows: It has excellent effects.

That is, the amount of frictional charge between toner particles is uniform, and the amount of charge can be easily controlled. In addition, the toner is extremely stable, with no variation or decrease in the amount of triboelectric charge due to deterioration during use. Therefore, problems such as toner scattering and contamination of the electrophotographic photosensitive material and copying machine as described above are eliminated, as well as phenomena such as toner aggregation, agglomeration, and low-temperature flow during storage, which were major drawbacks in the past. This is a toner that can withstand long-term storage without causing
! It also has excellent abrasion resistance, fixing properties, and adhesive properties.

This excellent effect of toner is further enhanced when it is used in a repetitive transfer copying system in which the operations of charging, exposure, development, and transfer are successively repeated. Furthermore, since there is little color disturbance caused by the charge control agent, it is possible to form color images with excellent colors when used as a color electrophotographic toner.

〔Example〕

The present invention will be specifically explained below with reference to Examples, but this is not intended to limit the present invention in any way. All parts in the following formulations are by weight.

Example 1 Styrene/butyl acrylate (80/20) copolymer 100 parts (weight average molecular weight Mw: approximately 300,000) Carbon black (Mitsubishi #44) 10 parts Individual molecular weight polyethylene wax 2 parts Compound (1)
Two parts of the above materials were thoroughly mixed in a blender and then kneaded with two rolls heated to 150°C. After the kneaded material is left to cool naturally, it is roughly pulverized using a cutter mill, then pulverized using a pulverizer using a jet stream, and further classified using an air classifier to obtain a fine powder with a particle size of 5 to 20 hiro. Obtained.

A developer was prepared by mixing 5 parts of the fine powder with 100 parts of iron powder carrier having an average particle size of 50 to 80 tons.

Next, a negative electrostatic image is formed on the OpC photoconductor by a conventionally known electrophotographic method, and this is powder-developed using the above-mentioned developer using a magnetic brush method to create a toner image, which is transferred to plain paper. The film was then heat-fixed. The resulting transferred image had a sufficiently high density, no fogging, and no toner scattering around the image, resulting in a good image with high resolution. Transfer images were continuously created using the above developer to examine durability, and the transferred images after 30,000 sheets were also compared with the initial images.

It was a completely unremarkable image.

Further, during durability, the above-mentioned filming phenomenon related to toner on the photoreceptor was not observed at all, and no problems were found in the cleaning process. Also, there were no troubles in the fixing process at this time, and at the end of the durability test of 30.0QO sheets, the fuser was disassembled and observed, but there were no scratches or damage to the rollers, and there was almost no dirt from offset toner, so there was no problem in practical use. There were no problems.

In addition, when the environmental conditions were set to 35°C and 85%, the image density was almost the same as at room temperature and humidity, and clear images with no fogging or scattering were obtained, and the durability remained unchanged up to 30,000 sheets. When a transferred and fixed image was obtained at a low temperature and low humidity of 15° C. and 110%, the image density was sufficiently high, solid black was developed and transferred very smoothly, and the image was excellent with no scattering or hollow spots. Durability was carried out under these environmental conditions, and although copies were made continuously and intermittently,
Again, the density fluctuation was ±0.2 up to 30,000 sheets, which was sufficient for practical use.

Comparative Example 1 A developer was obtained in the same manner as in Example 1, except that 2 parts of nigrosine dye (Nigrosine Base EX manufactured by Orient Chemical Industry Co., Ltd.) was used instead of 2 parts of compound (1).

Development, transfer, and fixing were performed to obtain an image in the same manner.

At room temperature, there was little fog, but the image density was low at 1.06, line drawings were scattered, and solid black was noticeably rough. Durability was investigated, and the density decreased to 0.83 after 30,000 sheets.

Also, during durability, after about 10,000 sheets, toner material formed a thin strip-like film on the surface of the photoreceptor and began to appear as lines on the image. This is so-called filming, and is thought to be due to the charge control agent changing the lubricity of the toner powder.

Furthermore, during durability, the fixed image tended to get caught up in the fixing roller during the fixing process, and there was difficulty in peeling it off from the roller.

When an image was obtained under conditions of 35° C. and 185%, the image density was as low as 0.88, and fogging, scattering, and roughness increased. Transfer efficiency was also low.

When an image was obtained under the conditions of 15° C. and tO%, the image density was as low as 0.91, and there was severe scattering, fogging, roughness, and noticeable transfer omissions. I tried to take continuous images, but
After about 30,000 sheets, the density became 0.53, making it impractical.

Example 2 A developer was obtained in the same manner as in Example 1 except that 3 parts of compound (2) was used instead of 2 parts of compound (1), and an image was obtained in the same manner by performing development, transfer, and fixing.

The detailed results are shown in Tables 1 and 2, and satisfactory results almost the same as in Example 1 were obtained.

Example 3 A developer was obtained in the same manner as in Example 1 except that 2 parts of compound (3) was used instead of 2 parts of compound (1), and development, transfer, and
Fixation was performed and an image was obtained in the same manner.

The detailed results are shown in Tables 1 and 2, and almost the same satisfactory results as in Example 1 were obtained.

Example 4 A developer was obtained in the same manner as in Example 1 except that 2 parts of Compound (0) was used instead of 2 parts of Compound (1), and an image was obtained in the same manner by performing development, transfer, and fixing.

The detailed results are shown in Tables 1 and 2, and almost the same satisfactory results as in Example 1 were obtained.

Example 5 Styrene/butyl acrylate (8o/20) copolymer 100 parts (weight average molecular weight: approx. 300,000) Triiron tetroxide EPT-500 (Toda Kogyo Department) 600 parts Low molecular weight polypropylene wax 2 parts Compound (1)2
After thoroughly mixing the above materials using a blender, they were kneaded using two rolls heated to 150°C. After the kneaded material was left to cool naturally, it was roughly pulverized with a cutter mill, then pulverized with a pulverizer using a diz-/F air flow, and further classified using an air classifier to obtain particles with a particle size of 5 to 20 IL. A fine powder was obtained.

Next, hydrophobic colloidal silica R was added to 100 parts of the fine powder.
0.4 part of -972 (manufactured by Nippon Aerosil Co., Ltd.) was mixed in a sample mill to prepare a -component magnetic toner.

When this toner was applied to a commercially available copying machine (trade name: MP-1502, manufactured by Canon ■) and an image was printed, good results similar to those of Example 1 were obtained.

Example 6 A developer was obtained in the same manner as in Example 5, except that 3 parts of compound (2) was used instead of 2 parts of compound (1), and development, transfer, and fixing were carried out in the same manner. I got it.

Detailed results are shown in Tables 1 and 2, and almost the same satisfactory results as in Example 5 were obtained.

Example 7 A developer was obtained in the same manner as in Example 5, except that 2 parts of compound (3) was used instead of 2 parts of compound (1), and development, transfer, and fixing were carried out in the same manner as in Example 5. I got it.

The detailed results are shown in Tables 1 and 2, and almost the same satisfactory results as in Example 5 were obtained.

Comparative example 2 In place of 2 parts of compound (1) in Example 5.

A developer was obtained in the same manner as in Example 5, except that 2 parts of benzylmethyl-hexadecyl ammonium chloride was used, and an image was obtained in the same manner. At room temperature, there was little fog, but the image density was low at 0.81, line drawings were scattered, and solid blacks were noticeably rough. Durability was investigated, and the density decreased to 0.48 after 30,000 sheets.

Also, the above-mentioned filming phenomenon during durability and problems in the fixing process seemed to be almost the same as in Comparative Example 1, and there were no problems.

When an image was obtained at 35° C. and 185%, the image density was as low as 0.72, and fogging, scattering, and roughness increased, making it unusable. Transfer efficiency was also low. When an image was obtained under the conditions of 15° C. and 10%, the image density was as low as 0.73, and there was severe scattering, fogging, roughness, and transfer omissions were noticeable. Continuous image formation was performed, but the density became 0.59 after 30,000 sheets, making it impractical.

Example 8 Styrene/butyl acrylate (go/20) copolymer 100 parts (weight average molecular weight Mw: approximately 300,000) Copper phthalocyanine blue pigment 5 parts Low molecular weight polypropylene wax 2 parts Compound (1) 2 parts The above materials were mixed with Brengu. After thorough mixing, the mixture was kneaded using two rolls heated to 150°C. After the kneaded material was left to cool naturally, it was roughly pulverized using a cutter mill, then pulverized using a pulverizer using a jet stream, and further classified using an air classifier to obtain particles with a particle size of 5 to 2011. A fine powder was obtained.

Next, 50 g of magnetic particles having a particle size of 50 to 80 l were mixed with 100 parts of the fine powder to prepare a developer.

When images were developed using this developer using the development method described below, good images with a bright blue color were obtained, and after 1,500 images, the toner/carrier was 10
Even when the weight was 750 g, there was almost no change in image density, and after that, images were printed on up to 30,000 sheets while replenishing toner, and good images were obtained.

This developing method will be explained using FIG. 1.

The carrier-toner mixture formed on the toner carrier 2 is circulated by the magnetic brush 52 by rotating the toner carrier 2, and the toner in the hopper 3 is taken in and coated in a uniform thin layer on the carrier 2. Then, the toner carrier 2 and the electrostatic image carrier 1 are made to face each other with a gap greater than the thickness of the toner layer, and the toner 5 on the carrier 2 is statically transferred. The image is developed by flying onto the electrostatic charge image on the image carrier 1.

The thickness of the toner layer is controlled by the size of the magnetic brush 52, the amount of magnetic particles, and the regulating blade 58. The gap between the electrostatic image carrier 1 and the toner carrier 2 may be made larger than the thickness of the toner, and the developing bias 6 may be applied.

The evaluation results of each example and comparative example are shown in Tables 1 and 2. In the table, O indicates good, 0Δ indicates slightly good, Δ indicates slightly poor, and X indicates poor.

:Effect of the invention〕 The effects obtained by the present invention are as follows.

By using the toner for developing electrostatic images of the present invention, (1) the amount of triboelectric charge between toner particles, between toner and carrier, between toner and toner carrier such as a sleeve in the case of -component development is stabilized; , and the triboelectric charge distribution becomes sharp and uniform, allowing the charge amount to be controlled to suit the developing system used.

(2) It is possible to develop and transfer a latent image faithfully, and even when used continuously for a long period of time, it maintains its initial characteristics and does not cause toner aggregation or change in charging characteristics.

(3) Stable images that are unaffected by changes in temperature and humidity can be reproduced, and images in vivid chromatic colors can be obtained.

(4) The cleaning process is facilitated without staining, abrading, or scratching the electrostatic latent image surface, and the fixing properties are excellent, and there are no problems even with high-temperature offset, which is particularly likely to cause trouble.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an example of a developing device to which the positively chargeable toner according to the present invention can be applied. 1... Electrostatic image holder, 2... Toner carrier, 3...
...Hopper 5...Toner, 6...Bias, 50...Magnet, 52...Magnetic brush,
58...Regulation blade. Figure 1

Claims (1)

[Scope of Claims] An electrophotographic toner for developing an electrostatic image, which is characterized by containing a 2-aminobenzimidazole represented by the general formula [1]. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [1] [In the formula, R_1 and R_2 are hydrogen atoms, halogen atoms, alkyl groups, aryl groups, aralkyl groups, alkoxy groups,
It represents an aryloxy group, an aralkyloxy group, an alkylthio group, an arylthio group, an aralkylthio group, or a nitro group, and may be the same or different, and the alkyl chain and aryl ring may be substituted. ]