JPH0443366A - Electrostatic image developing toner - Google Patents

Abstract

PURPOSE:To obtain the toner which has a sufficient triboelectrostatic charge quantity, is uniform in the triboelectrostatic charge quantity between the toners and is free from fogging by incorporating at least one kind of compds. having mercaptoimidazole skeleton or cyclic thiourea skeleton. CONSTITUTION:At least one kind of compds. having mercaptoimidazole skeleton or cyclic thiourea skeleton are incorporated into this toner. Namely, the compds. having the mercaptoimidazole skeleton or the cyclic thiourea skeleton have sufficient triboelectrostatic chargeability. When the compds. are incorporated into the toner, this toner has the sufficient triboelectrostatic charge quantity. The sufficient triboelectrostatic charge quantity is obtd. in this way and the triboelectrostatic charge quantity between the toners is uniform. The high density and sharp images are thus obtd. and the images of a sufficient density are obtd. even after copying in a large amt.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a toner for visualizing an electrostatic charge replacement image in image forming methods such as electrophotography and electrostatic recording.

(Prior art) Conventionally, as an electrophotographic method, US Patent No. 2,297.69
Various methods are described in Japanese Patent Publication No. 1, Japanese Patent Publication No. 42-23910, Japanese Patent Publication No. 43-24748, etc.

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

As toners applied to these dry developing methods, fine powders in which dyes and pigments are dispersed in natural or synthetic resins have conventionally been used. For example, particles obtained by dispersing a colorant in a binder resin such as polystyrene and pulverizing the particles to about 1 to 30 μm are used as the toner. As the magnetic toner, one containing magnetic particles such as magnetite is used.

Further, in the case of a system using a two-component developer, the toner is usually mixed with carrier particles such as glass beads and iron powder.

Depending on the polarity of the electrostatic latent image developed with any toner,
Must have a positive or negative charge.

In order to make the toner retain an electric charge, it is possible to use the triboelectricity of the resin that is a component of the toner, but since the toner has a low chargeability with this method, the image obtained by development is prone to fogging and is unclear. Become something. Therefore, in order to impart appropriate triboelectric chargeability to the toner, dyes and pigments that impart chargeability, as well as charge control agents are added.

Charge control agents known in the art today include metal complexes of monoazo dyes, salicylic acid, naphthoic acid,
Metal complex salts of dicarboxylic acids, copper phthalocyanine pigments, etc. are known.

(Problem to be Solved by the Invention) However, since some of these charge control agents tend to contaminate the sleeve or carrier, the amount of triboelectric charge of toners using them decreases as the number of copies increases. Causes a decrease in image density. Further, some charge control agents have an insufficient amount of triboelectrification and are easily affected by temperature and humidity, which causes environmental fluctuations in image density. Furthermore, some charge control agents have poor storage stability, and their triboelectric charging ability decreases during long-term storage. Furthermore, since some charge control agents have poor dispersibility in resins, toners using such agents have uneven triboelectric charge between particles and are prone to capping. Furthermore, some charge control agents have poor thermal stability and may decompose and deteriorate during the heating and kneading process during toner production. A toner produced by reusing a portion of a toner using such a charge control agent tends to generate oppositely charged particles and tends to cause fogging. Also, some charge control agents are colored and cannot be used in color toners.

Therefore, an object of the present invention is to develop a charge control agent that satisfies all of the above, and to provide a toner for developing electrostatic images that solves the above-mentioned problems.

(Means for solving problems) The above objects are achieved by the present invention as described below.

That is, the present invention is a toner for developing electrostatic images characterized by containing at least one compound having a mercaptoimidazole skeleton or a cyclic thiourea skeleton.

(Function) As a result of intensive studies to achieve the above object, the present inventors have found that a compound having a mercaptoimidazole skeleton or a cyclic thiourea skeleton has sufficient triboelectric charging ability, and when contained in a toner. It has been found that the toner has a sufficient amount of triboelectric charge.

Furthermore, mercaptoimidazole or mercaptotetrazole, which may have a substituent, or 0-phenylenethiourea, which may have a substituent, has sufficient triboelectric charging ability and is colorless or substantially colorless, The present inventors have discovered that when incorporated into a toner, this toner has a sufficient amount of triboelectric charge, solves the above problems, and can be used as a color toner.

(Preferred Embodiments) Next, the present invention will be described in more detail by citing preferred embodiments.

A compound having a mercaptoimidazole skeleton or a cyclic thiourea skeleton, or a mercaptobenzimidazole compound or a mercaptotetrazole used in the present invention,
Alternatively, the O-phenylenethiourea compound may have a substituent.

Substituents of these compounds having a mercaptoimidazole skeleton or a cyclic thiourea skeleton, mercaptobenzimidazole compounds, or 0-phenylenethiourea compounds include a hydroxy group, a carboxy group, a halogeno group, a nitro group, a trihalogenomethyl group, Cyano group, sulfoxy group, alkyl group having 1 to 12 carbon atoms, 1 to 12 carbon atoms
aryl group, alkoxy group having 1 to 8 carbon atoms, 1 carbon number
~12 aryloxy group, amine group having 1 to 12 carbon atoms,
Acyloxy group having 1 to 12 carbon atoms, acylamido group having 1 to 12 carbon atoms, thioxy group having 1 to 12 carbon atoms, 1 to 12 carbon atoms
Examples thereof include a sulfonyl group having 12 carbon atoms, a sulfinyl group having 1 to 12 carbon atoms, and the like. It may have one or more substituents, and
Two substituents may form a ring structure.

The toner of the present invention contains a compound having the above mercaptoimidazole skeleton or cyclic thiourea skeleton, a mercaptobenzimidazole compound, a mercaptotetrazole, or an 0-phenylenethiourea compound as a negatively charged charge control agent.

Mercaptobenzimidazole compounds exhibit high negative chargeability, excellent thermal stability, and low water absorption.
In addition, it is colorless or has a light color that causes virtually no problems. Therefore, when the mercaptobenzimidazole compounds of the present invention are contained in a toner, it has high negative chargeability and has little environmental dependence in the amount of charge, and the mercaptobenzimidazole compound decomposes and deteriorates during heating and kneading. Therefore, when a copied image is obtained using the obtained toner, no fogging occurs in the image. Furthermore, when used in color toners, clear copied images can be obtained since the color tone is less likely to be disturbed.

There are no known examples in which mercaptobenzimidazole compounds or mercaptotetrazole are used as components of toner compositions (the toner of the present invention is a completely new toner composition).
Aminobenzothiazole has been proposed in Japanese Patent Publication No. 7 and Japanese Unexamined Patent Publication No. 60-117257, but their purpose is to control positive chargeability, which is different from the purpose of the present invention.

Furthermore, even in the case of a compound having an imidazole skeleton or tetrazole, a toner containing the same exhibits positive chargeability, which is also different from the purpose of the present invention.

Although the cause is unknown, by introducing a mercapto group onto the carbon between two nitrogens of this imidazole skeleton or tetrazole skeleton to form a mercapto-imidazole skeleton or mercaptotetrazole, it becomes negatively chargeable.

Examples of thiourea-based compounds used as toner compositions include thiourea compounds having an alkyl group or phenyl group as a substituent, as disclosed in JP-A-61-110157 or JP-A-63-214763. has been proposed as a charge control agent. However, when we examined the thioureas listed above, we found that thioureas with alkyl groups showed weak positive chargeability, and even thioureas with phenyl groups had low negative triboelectricity, making it difficult to use alone as a charge control agent. It has been found that they are difficult to use and, if used, require significant restrictions on other toner raw materials or developer materials.

Therefore, by linking the two nitrogen atoms on thiourea using a linking group such as arylene, ethylene, azo, or carbonyl compound to form a ring, it has high negative triboelectric charging properties. In particular, compounds in which the linking group is arylene or the like have more favorable properties, since the thermal stability of the compound is improved and water absorption is reduced. Further, the cyclic structure to be formed may be a four- to six-membered ring, but a five-membered ring or a six-membered ring is preferable from the viewpoint of the amount of charge.

In addition, the compound having a mercaptoimidazole skeleton or cyclic thiourea skeleton, mercaptobenzimidazole compound, mercaptotetrazole, or O-phenylenethiourea compound used in the present invention has improved dispersibility in the binder resin. Frictional charging between toner particles became uniform, and generation of oppositely charged particles was suppressed, so that fogging did not occur. Furthermore, contamination of toner carriers such as sleeves and carriers could be reduced, and images of good quality could be obtained even when this toner was stored for a long time under high temperature and high pressure conditions. Furthermore, the dependence of the image on the environment is reduced, and an image with sufficient density can be obtained even under high temperature and high temperature conditions or under low temperature and low humidity.

As described above, the toner containing a compound having a mercaptoimidazole skeleton or a cyclic thiourea skeleton, a mercaptobenzimidazole compound, a mercaptotetrazole, or an 0-phenylenethiourea compound used in the present invention can be used as a conventional charge control agent. Compared to the toner containing the! The present invention was based on the discovery that this material has certain properties.

A compound having a mercaptoimidazole skeleton or a cyclic thiourea skeleton, a mercaptobenzimidazole compound, a mercaptotetrazole, or an 0-phenylenethiourea compound used in the present invention can be synthesized using a known method.

The compound having a mercaptoimidazole skeleton or the mercaptobenzimidazole compounds used in the present invention can be obtained, for example, by reacting carbon heptasulfide such as arylene diamine or alkylpotassium dithiocarbonate in an alcohol solvent.

Compounds having a cyclic thiourea skeleton or 0-phenylenethiourea compounds can also be obtained by isomerizing a tautomer, mercaptoimidazole.

Specific examples of compounds having a mercaptoimidazole skeleton, mercaptotetrazole, or cyclic thiourea skeleton, mercaptobenzimidazole compounds, or 0-phenylenethiourea compounds that can be used in the present invention are shown below; These are representative examples taken into consideration, and do not limit the present invention in any way.

Compound Example A method for incorporating the above charge control agent into a toner is as follows:
There are two methods: adding it inside the toner and adding it externally. The amount of these compounds to be 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 not specifically limited. , when internally added, preferably binder resin 10
It is used in an amount of 0.1 to 10 parts by weight, more preferably 0.1 to 5 parts by weight. When externally added, the amount is preferably 0.01 to 10 parts by weight per 100 parts by weight of the resin.

When externally added, it is particularly preferable to fix or embed the binder resin or colorant near the surface of the fine particles by mechanical impact.

First, as a pretreatment, the charge control agent (particles (B)) is dispersed and rubbed against the colored fine particles (particles (A)), so that the charge control agent (particles (B)) is attached to the colored fine particles by electrostatic force and van der Waals force. - A mixer with a high-speed stirring blade is used for boat fishing, but any mixer with a mixing function and molecular 1tlJ capacity will suffice.Also, you can also use a crusher, a vibrating mill, etc. with a reduced impact force. good. In order to make this pretreatment dispersion more uniform, fluidity imparting agents may be used as dispersion aids as necessary.
A lubricant, a conductivity imparting agent, etc. may be added.

The charge control additive of the present invention can also be used in combination with conventionally known charge control agents such as metal alkyl salicylate salts, metal complex salts of monoazo dyes, boron compounds, and sulfonic acid pendant resins.

Further, in the toner of the present invention, fine silica powder can be externally added to the toner. As the silica fine powder, silica fine powder produced by a dry method or a wet method can be used.

The dry method mentioned here is a method for producing fine silica powder produced by vapor phase oxidation of a silicon halide compound. For example, this method utilizes the thermal decomposition oxidation reaction of silicon tetrachloride gas in oxygen and hydrogen, and the basic reaction formula is as follows.

5iC1n + 2Hz + 02→SiO□+4H
In addition, in this manufacturing process, it is also possible to obtain a composite fine powder of silica and other metal-containing complexes by using other metal halide compounds, such as aluminum chloride or titanium chloride, together with the silicon halide compound, These are also included.

On the other hand, various conventionally known methods can be used to produce the silica fine powder used in the present invention by a wet method. For example, there is a method of decomposing sodium silicate using an acid as shown below in the general reaction formula.

NaxO・X5iOt + HCI + HzO-5i
Oz・n)lsO+ NaC1Other methods include decomposition of sodium silicate with ammonia salts or alkali salts, a method of generating alkaline earth metal silicate from sodium silicate and then decomposing it with acid to form silicic acid, sodium silicate There are two methods: converting the solution into silicic acid using an ion exchange resin, and using natural silicic acid or natural silicates.

As the silica fine powder referred to herein, any of anhydrous silicon dioxide (silica) and other silicates such as aluminum silicate, sodium silicate, potassium silicate, magnesium silicate, and zinc silicate can be used.

Among the silica fine powders mentioned above, the specific surface area due to nitrogen adsorption measured by the BET method is 30rd/g or more (especially 50 to 40rd/g).
0rrf/g) gives good results.

Furthermore, the silica fine powder used in the present invention may be treated with a treatment agent such as a silane coupling agent, silicone oil, or an organic silicon compound for the purpose of hydrophobization, if necessary.
A known method is used for this purpose, and the treatment is performed with the above-mentioned treatment agent that reacts with or adsorbs the silica fine powder.

Examples of such treatment agents include hexamethyldisilazane, vinyltrimethoxysilane, vinyltriethoxysilane, trimethylsilane, trimethylchlorosilane,
trimethylethoxysilane, dimethylethoxysilane,
Methyltrichlorosilane, allyldimethylchlorosilane, allyl phenyldichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, a-
Chlorethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyljethoxysilane, hexa Methyldisiloxane, 1,3-divinyltetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane and siloxane units having 2 to 12 siloxane units per molecule, each having Si per unit in the terminal position. There are dimethylpolysiloxanes containing hydroxyl groups bonded to . These may be used alone or in a mixture of two or more.

Finally, the degree of hydrophobicity of the treated silica fine powder was determined as 3 as the degree of hydrophobicity measured by methanol titration test.
When the developer is hydrophobized so as to exhibit a value in the range of 0 to 80, the amount of triboelectric charge of the developer containing such fine silica powder becomes sharp and exhibits uniform negative electrification, which is preferable.

Here, in the methanol titration test, the degree of hydrophobization of the silica fine powder having a hydrophobized surface is confirmed.

In order to evaluate the degree of hydrophobicity of the treated silica fine powder, the ``methanol titration test'' specified herein is carried out as follows.
Add to 50 mρ of water in a β Erlenmeyer flask. Methanol is titrated from the burette until all of the silica is wetted. At this time, the solution in the flask is constantly stirred using a magnetic cooler. The end point is observed when the entire amount of fine silica powder is suspended in the M-form, and the degree of hydrophobization is expressed as the percentage of methanol in the liquid mixture of methanol and water when the end point is reached.

The coloring agents used in the present invention include carbon black, lamp black, 1-man, ultramarine blue, nigrosine dye, aniline blue, phthalocyanine blue, phthalocyanine green, Visor Yellow G, rhodamine 6G, calco oil blue, chrome yellow, and quinacridone. , benzidine yellow, rose bengal, triarylmethane dyes, monoazo dyes, disazo dyes and pigments, and other conventionally known dyes and pigments may be used alone or in combination.

Examples of the resin used in the present invention include homopolymers of styrene and its substituted products such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene; styrene-p-chlorostyrene copolymers, and styrene-vinyltoluene copolymers. Polymer, styrene-vinylnaphthalene copolymer, styrene-acrylic ester copolymer, styrene-methacrylic ester copolymer, styrene-α-methyl chloromethacrylate copolymer, styrene-acrylonitrile copolymer, styrene- Styrene such as vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer System copolymer; polyvinyl chloride, phenolic resin, natural resin-modified phenolic resin, natural resin-modified maleic acid resin,
Acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane resin, polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral resin, tenben resin, coumaron indene resin, petroleum resin, etc. can be used. .

Further, crosslinked styrenic copolymers are also preferred binder resins. Examples of comonomers for the styrene monomer in the styrene copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, and -2 acrylate.
- monocarboxylic acids having double bonds or substitutes thereof, such as ethylhexyl, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, etc.; For example, dicarboxylic acids with double bonds such as maleic acid, butyl maleate, methyl maleate, dimethyl maleate, etc.; and substituted products thereof; For example, vinyl esters such as vinyl chloride, vinyl acetate, vinyl benzoate, etc. : Ethylene olefins such as ethylene, propylene, butylene, etc. Vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, etc. Vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, etc. Vinyl monomers such as ; may be used alone or in combination.

As the crosslinking agent, compounds having two or more polymerizable double bonds are mainly used, such as aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; for example, ethylene glycol diacrylate and ethylene glycol diacrylate. Carboxylic acid esters having two double bonds such as methacrylate and 1,3-butanediol dimethacrylate; divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide, and divinyl sulfone; and having three or more vinyl groups. Compound;
may be used alone or as a mixture.

In addition, when a pressure fixing method is used for fixing, it is possible to use a binder resin for pressure fixing toners, such as polyethylene, polypropylene, polymethylene, polyurethane elastomer, ethylene-ethyl acrylate copolymer,
Examples include ethylene-vinyl acetate copolymer, ionomer resin, styrene-butadiene copolymer, styrene-isoprene copolymer, linear saturated polyester, paraffin, and the like.

Further, the static color development type toner of the present invention can be used by containing a magnetic material. The magnetic materials used include iron oxides such as magnetite, γ-iron oxide, ferrite, and iron-rich ferrite; metals such as Fe, Co, and Nj;
Or these metals and AI, CO1Cu, Pb, Mg
, Ni, Sn, Zn, Sb, Be, Bi,
Examples include alloys with metals such as Cd, Ca, Mn, Se, Ti, W, and mixtures thereof.

These LiH materials preferably have an average particle size of about 01 to 2 μm, preferably about 0.1 to 045 μm,
The content of the magnetic substance in the competitive toner is 40 to 150 parts by weight, preferably 60 to 1 part by weight, based on 100 parts by weight of the binder resin.
In a magnetic toner containing 20 parts by weight of the charge control agent, a toner having a volume average particle diameter of 3 to 15 μm can be used. In particular, 12 to 60 number % of magnetic toner particles having a particle size of 5 μm or less are contained, and 1 to 33 number % of magnetic toner particles having a particle size of 8 to 12.7 μm are contained,
2.0% of magnetic toner particles have a particle size of 16 μm or more
Contained by volume% or less, the volume average particle size of the magnetic toner is 4 to 4%.
A thickness of 10 μm is more preferable from the viewpoint of development characteristics.

The particle size distribution of toner can be measured by various methods.
In the present invention, it is appropriate to use a Coulter counter.

That is, the measuring device is Coulter counter TA-n.
A mold (manufactured by Coulter) was used, and an interface (manufactured by Nikkaki) that outputs the number distribution and volume distribution was connected to a CX-1 personal computer (manufactured by Canon), and the electrolyte was 1st grade sodium chloride. Prepare a 1% NaCff aqueous solution.

For example, 15OTON■-■ (manufactured by Coulter Scientific Japan) can be used.

As a measurement method, the electrolytic aqueous solution 100 to 150 + t + j
A surfactant, preferably an alkylbenzene sulfonate, is added to 2 as a dispersant at 0.1 to 5 m°C, and 2 to 20 mg of the measurement sample is added. The electrolytic solution in which the sample was suspended was treated with an ultrasonic disperser for about 1 to 3 minutes, and the aperture was set to 100 mm using the Coulter counter TA-II model.
Using a μm aperture, 2 to 40 μm based on the number of pieces.
The particle size distribution of the particles m is measured to determine the value of the particle size distribution of the non-magnetic toner.

Furthermore, the toner of the present invention can be mixed with a carrier and used as a two-component toner. As the carrier that can be used in the present invention, known carriers can be used, for example,
Examples include magnetic powders such as iron powder, ferrite powder, and nickel powder, glass beads, and those whose surfaces are treated with resin or the like. In addition, examples of the resin that coats the carrier surface include styrene-acrylic ester copolymer, styrene-methacrylic ester copolymer, acrylic ester copolymer, methacrylic ester copolymer, silicone resin, fluorine-containing resin, Polyamide resins, ionomer resins, polyphenylene sulfide resins, etc. or mixtures thereof can be used.

The toner of the present invention may contain additives, if necessary. Examples of additives include lubricants such as zinc stearate, abrasives such as cerium oxide and silicon carbide, flow agents such as aluminum oxide, anti-caking agents, and conductive agents such as carbon black and tin oxide. There is uniformity in granting.

Further, fine powder of a fluorine-containing polymer such as fine powder of polyvinylidene fluoride is also a preferable additive from the viewpoint of fluidity, polishability, charging stability, and the like.

In addition, in order to improve mold release properties during hot roll fixing, waxy substances such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, carnauba wax, Sasol wax, paraffin wax, etc.
Adding about 5% by weight to the toner is also one of the preferred embodiments of the present invention.

In manufacturing the toner according to the present invention, the toner constituent materials as described above are sufficiently mixed using a ball mill or other mixer, and then kneaded (kneaded) using an external kneader such as a hot roll kneader or an extruder, and then cooled. After solidification, it is preferable to obtain the toner by mechanical crushing and classification.Other methods include dispersing the constituent materials in a binder resin solution and then spray drying to obtain the toner. (Makoa material,
In a so-called microcapsule toner made of a shell material, a method such as method 1 in which a predetermined material is contained in the core material, the shell material, or both can be applied.

Furthermore, a prescribed material is mixed with the monomers that constitute the binder resin and emulsified! ! It is possible to apply the polymerization method to obtain toner by polymerizing it into a cloudy liquid and toner packaging method.

Furthermore, the toner according to the present invention can be produced by sufficiently mixing desired additives with a mixer such as a Henschel mixer, if necessary.

The toner containing the charge control agent of the present invention can be used in any development for making an electrostatic charge image visible in electrophotography, electrostatic recording, electrostatic printing, etc. by conventionally known means.

(Examples) Hereinafter, the present invention will be specifically explained using Examples, but these are not intended to limit the present invention in any way.

Note that all parts in the following formulations are parts by weight.

Example 1 Styrene/n-butyl methacrylate 100 parts Carbon black 5 parts Compound example (
1) Two parts of the above materials were mixed in a blender (after mixing, they were kneaded in a twin-screw kneading extruder set at 150°C. The obtained kneaded product was cooled, coarsely pulverized in a cutter mill, and then heated in a jet stream. The resulting finely ground powder was classified using a fixed-wall type air classifier.

Furthermore, the obtained classified powder was strictly classified and removed at the same time using a multi-division classifier (manufactured by Nippon Steel Mining Co., Ltd., Elbow Jet Classifier) that utilizes the Coanda effect, resulting in a volume average particle size of 8.1μ.
A fine powder of m was obtained.

100 parts of the obtained fine powder was added with silica fine powder (BET specific surface area: 300
rf/g) was added and mixed using a Henschel mixer to obtain a toner.

Next, 5 parts of the obtained toner were mixed with 100 parts of an acrylic coated ferrite carrier having an average particle size of 65 μm to prepare a developer.

This developer was applied to a commercially available color electrophotographic copying machine CLC-1 (
A copying test was conducted using a Canon (trade name).

As a result, under the environmental conditions of 23° C./60%, a bright black image with an image density of 1.45 was obtained from the initial stage, and no deterioration was observed after 20,000 copies were made.

Next, when a copying test was conducted under environmental conditions of 15° C./10%, an image with a high density of 1.42 was obtained from the initial stage. Furthermore, the concentration was 1.47 even under the environmental conditions of 32℃/85%.
Good images were obtained.

Example 2 Same as Example 1 except that 5 parts of carbon black in Example 1 was replaced with 4 parts of copper phthalocyanine pigment (C, 1, Pigment Blue 15:3), except that the volume average particle diameter was 8.5 μm.
A fine powder was obtained, and silica was further mixed therein to obtain a toner.

Next, the same carrier as in Example 1 was mixed in the same ratio,
It was used as a developer.

This developer was subjected to a copying test in the same manner as in Example 1.

As a result, under environmental conditions of 23° C./60%, a good blue image with a density of 1.45 and no fog was obtained from the initial stage.

No deterioration in image quality was observed even after 20,000 copies were made.

Copying tests were also conducted under the environmental conditions of 35°C/85% and 15°C/10%, and similar good results were obtained as in the case of 23°C/60%.

Example 3 Fine powder with a volume average particle diameter of 8.5 μm was obtained in the same manner as in Example 1, except that 5 parts of carbon black in Example 1 was replaced with 4 parts of quinacridone pigment (C, I Pigment Red 122), and silica was further added. A toner was obtained by mixing.

Next, the same carrier as in Example 1 was mixed in the same ratio,
It was used as a developer.

This developer was subjected to a copying test in the same manner as in Example 1.

As a result, under environmental conditions of 23° C./60%, a good magenta image with a density of 1.46 and no fog was obtained from the initial stage. No deterioration in image quality was observed even after 20,000 copies were made.

Copying tests were also conducted under the environmental conditions of 35°C/85% and 15°C/10%, and similar good results were obtained as in the case of 23°C/60%.

Example 4 5 parts of carbon black in Example 1 was mixed with yellow pigment (C
, 1, Pigment Yellow 17) Same as Example 1 except for replacing with 5 parts! *A fine powder with a product average particle diameter of 8.2 LLm was obtained, and silica was further mixed therein to obtain a toner.

Next, the same carrier as in Example 1 was mixed at a ratio of 100 parts of carrier to 6 parts of toner to prepare a developer.

This developer was subjected to a copying test in the same manner as in Example 1.

As a result, under the environmental conditions of 23° C./60%, a good yellow image with a density of 1.45 and no fog was obtained from the initial stage.

No deterioration in image quality was observed even after 20,000 copies were made.

Copying tests were also conducted under the environmental conditions of 35°C/85% and 15°C/10%, and similar good results were obtained as in the case of 23°C/60%.

Example 5 A full-color image was obtained using the black, cyan, magenta, and yellow developers used in Examples 1 to 4.
A vivid full-color image with excellent color mixing and gradation was obtained.

Example 6 Styrene/n-butyl methacrylate 100 parts Magnetic material 80 parts Low molecular weight polypropylene wax 3 parts Compound example (5) 3 parts The above materials were thoroughly mixed in a blender, and then mixed in a twin-screw kneading extruder set at 140°C. Kneaded. The obtained mixed material was cooled and coarsely pulverized using a cutter mill, then finely pulverized using a pulverizer using a jet stream, and the obtained pulverized powder was classified using a fixed wall type wind classifier.

Furthermore, the obtained classified powder was strictly classified and removed at the same time using a multi-division classifier (manufactured by Nippon Steel Mining Co., Ltd., Elbow Jet Classifier) that utilizes the Coanda effect to reduce the volume average particle size to 8.5μ.
A fine powder of m was obtained.

100 parts of the obtained fine powder was added with silica fine powder (BET specific surface area: 300
+d/g) was added and mixed using a Henschel mixer to obtain a magnetic toner.

When this toner was applied to a commercially available copying machine (product name NP-6650, manufactured by Canon ■) under the environmental conditions of 23°C/60%, there was no fogging or roughness (, A clear image with a resolution of 6.3 lines/m m was obtained.After further continuous copying of 50,000 copies to examine durability, the image density was 1.34 and the resolution was 6.3 lines/m m
A good image comparable to the initial image was obtained.

Further, when the amount of triboelectric charge of the toner on the developing sleeve was measured, it was -116 .mu.C/g at the initial stage, and -11.1 .mu.c/g after 50,000 copies, showing that almost no sleeve contamination was observed.

Then, when a copying test was carried out under the environmental conditions of 15° C./10%, similarly high density and good quality images were obtained. 5
Similarly, good results were obtained in a continuous copying test of 10,000 sheets.

When the same copying test and continuous copying test were conducted under the environmental conditions of 35° C./85%, good results were obtained.

Example 7 Styrene/n-butyl methacrylate 100 parts Magnetic material 60 parts Low molecular weight polypropylene wax 2 parts Compound example (7) 2 parts The above materials were mixed in a blender (after mixing, they were placed in a twin-screw kneading extruder set at 140°C). The resulting mixture was cooled and coarsely pulverized using a cutter mill, then finely pulverized using a pulverizer using a jet stream, and the resulting pulverized powder was passed through a fixed-wall wind classifier. It was classified by.

Furthermore, the obtained classified material was classified and removed using a multi-segmentation classifier (manufactured by Nippon Steel Mining Co., Ltd., Elbow Jet Classifier 1m) that utilizes the Coanda effect to obtain a volume average particle size of 11.5 μm.
A fine powder was obtained.

Obtained fine powder] 00 parts of silica fine powder hydrophobized with silicone oil (BET specific surface area 200 r&/
g) 0.4 part was added and mixed in a Henschel mixer to obtain a magnetic toner.

When this toner was applied to a commercially available copying machine (trade name NP-6650, Canon (side type)) and a copying test was conducted under environmental conditions of 23°C/60%, the image a degree was as high as 32, and there was no fogging. A clear image without any roughness was obtained.
When we investigated the durability performance by continuously copying 10,000 frames, we found that the image density was 1.
．． 31, and a good image comparable to the initial image was obtained.

Next, when a copying test was carried out under the environmental conditions of 15° C. and 710%, similarly high density and good quality images were obtained. 2
Similarly, good results were obtained in a continuous copying test of 10,000 sheets.

When the same copying test and continuous copying test were conducted under the environmental conditions of 35° C./85%, good results were obtained.

Example 8 Styrene/n-butyl methacrylate 100 parts Copper phthalocyanine pigment (C,1, Pigment Blue 15
) 5 parts Low molecular weight polypropylene wax 3 parts Compound example (
2) 3 parts The above materials were thoroughly mixed in a blender, and then kneaded in a twin-screw kneading extruder set at 140°C. The obtained kneaded product was cooled and coarsely pulverized using a cutter mill, then finely pulverized using a pulverizer using a jet stream, and the obtained pulverized powder was classified using a fixed wall type wind classifier.

Furthermore, the obtained classified powder was simultaneously strictly classified and removed to remove ultra-fine powder using a multi-division classifier (manufactured by Nichi-Euro Mining Co., Ltd., Erbojieto Classifier) that utilizes the Coanda effect to obtain a volume average particle size of 12.
A fine powder of 1 μm was obtained.

100 parts of the obtained fine powder was treated with silica fine powder (BET specific surface area 200r/
/g) was added and mixed with a Henschel mixer to prepare a toner.

Next, 8 parts of the obtained toner were mixed with 100 parts of an acrylic coated ferrite carrier having an average particle size of 65 μm to prepare a developer.

When this developer was applied to a commercially available copying machine (product name NP-6650, manufactured by Canon ■) and a copying test was conducted under environmental conditions of 23°C/60%, the image density was 1.34, indicating good image quality. Image obtained. Using the above developer, 3,000
When the durability was examined by continuous copying, it was found that a good image comparable to the initial image was obtained.

Next, when copying tests were conducted under environmental conditions of 15°C/10% and 35°C/83%, similarly good results were obtained.

Example 9 Polyester (acid value 9.5 mgKOH) l/g, hydroxyl value 16.3 mgKOH/g) 1
00 parts Carbon black 5 parts Compound example (11) 3 parts After mixing the upper materials well in a blender, the mixture was heated to 150°C.
The mixture was kneaded using a axial kneading extruder. Cool the obtained kneaded product,
After coarsely pulverizing it with a cutter mill, it was finely pulverized using a pulverizer using a jet stream, and the obtained pulverized powder was classified using a fixed wall type wind classifier.

Furthermore, the obtained classified powder was simultaneously classified and removed by F15 densely to remove ultra-fine powder using a multi-division classifier using the Coanda effect (manufactured by Nihon-Euro Mining Co., Ltd., Elbow Jet Classifier) to obtain a volume average particle size of 8.
A fine powder of 5 μm was obtained.

100 parts of the obtained fine powder was treated with silica fine powder (BET specific surface area 300 r &
/g) was added and mixed with a Henschel mixer to prepare a toner.

Next, 5 parts of the obtained toner were mixed with 100 parts of an acrylic coated ferrite carrier having an average particle size of 65 μm to prepare a developer.

This developer was applied to a commercially available color electrophotographic copying machine CLC-1 (
I did a copy test with Canon (made by Kiki).

As a result, under the environmental conditions of 23° C./60%, a salmon-yagana colored image with an image density of 42 was obtained from the initial stage, and no deterioration was observed after 10,000 copies were made.

Next, when a copying test was conducted under environmental conditions of 15° C./10%, an image with a high density of 1.40 was obtained from the initial stage. Further:
2. Even under the Ji condition of 32°C/85%, a good image of 146 times was obtained.

(Effect of the invention) As described above, as a charge control agent, a compound having a mercaptoimidazole skeleton or an arylenethiourea skeleton,
Alternatively, the toner of the present invention containing a mercaptobenzimidazole that may have a substituent, a mercaptotetrazole, or an 0-phenylenethiourea that may have a substituent has a sufficient amount of triboelectric charge and The amount of triboelectric charge between toner particles is uniform, giving a clear image with high density.

In addition, since the contamination of toner carriers such as sleeves and carriers by charge control agents is reduced, images with sufficient density can be obtained even after making large quantities of copies, and the density is stable.

Furthermore, since the dependence of image density on temperature and humidity is small, images of good quality can be provided under a wide range of environmental conditions.

Further, since the charging side i-distributing agent does not decompose or change in quality during toner production, it provides good images without fogging.

Furthermore, it can be used in color toners because there is little color disturbance caused by the charge control agent.

Claims (3)

[Claims] (1) A toner for developing electrostatic images containing at least one compound having a mercaptoimidazole skeleton or a cyclic thiourea skeleton. (2) Claim 1 wherein the compound having a mercaptoimidazole skeleton is a mercaptobenzimidazole which may have a substituent, and the compound having a cyclic thiourea skeleton is an o-phenylenethiourea which may have a substituent. The electrostatic image developing toner described in . (3) A toner for developing electrostatic images containing a mercaptotetrazole compound.