JPH0611903A - Toner for developing electrostatic latent image - Google Patents

Abstract

PURPOSE:To maintain sufficiently high and stable capacity of electrification so as to provide a good buildup of frictional electrification and images of high density by putting at least an amidine compound in a toner. CONSTITUTION:A toner contains an amidine compound serving as a charge controlling additive. Preferably, the toner also contains a N,N<1>-diarylbenzamidine derivative expressed by the formula. In the formula, R<1> represents hydrogen, a C1-5 alkyl or amino group and the like, R<2> and R<3> represent hydrogen, a C1-8 alkyl, aralkyl or amino group and the like, and (k), (l) and (m) represent integers from 1 to 3. Addition of the amidine compound to the toner provides high capacity of electrification. Also, the speed of electrification is so high and the stability of the capacity of electrification at the buildup is so good that the toner has excellent environmental stability. The toner is dispersed so well in the resin that the possibility of contaminating sleeves and carriers is reduced, which makes the toner compatible with magnetic substance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charge control agent for visualizing an electrostatic latent image in an image forming method such as electrophotography and electrostatic recording.

[0002]

2. Description of the Related Art Conventionally, as an electrophotographic method, U.S. Pat. No. 2,297,691, Japanese Patent Publication No. 42-2,910.
Various methods are described in Japanese Patent Publication No. 43-24748 and Japanese Patent Publication No. 43-24748.

The developing methods applied to these electrophotographic methods and the like are roughly classified into a dry developing method and a wet developing method. The former is further divided into a method using a two-component developer and a method using a one-component developer.

As the toner applied to these dry developing methods, fine powder in which a dye or a pigment is dispersed in a natural or synthetic resin is conventionally used. For example, 1 to 30 is obtained by dispersing a colorant in a binder resin such as polystyrene.
Particles finely pulverized to about μm are used as a toner.
A magnetic toner containing magnetic particles such as magnetite is used. In the case of a system using a two-component developer, the toner is usually used by mixing it with carrier particles such as glass beads and iron powder.

Any toner must have a positive or negative charge, depending on the polarity of the electrostatic latent image being developed.

In order to retain the electric charge in the toner, it is possible to utilize the triboelectric charging property of the resin which is a component of the toner. However, in this method, most toners have insufficient charge amount or are unstable. There will be. In such cases,
The image obtained by the development is liable to be fogged and the density is likely to be lowered. Therefore, in order to impart an appropriate triboelectric charging property to the toner, a dye, a pigment or a charge control agent which imparts the charging property is added.

Examples of positive charge control agents known in the art today include nigrosine dyes, azine dyes, triphenylmethane dyes, quaternary ammonium salts, and polymers having a quaternary ammonium salt in the side chain. It has been known.

[0008]

The charge control agent is added to promote the charging of the toner, control the triboelectric charge amount, and maintain the triboelectric charge amount.

For example, if the charging speed of the toner is slow, the image density will be low immediately after replenishment of the toner or in the image of the first copy because the charging amount of the toner cannot rise sufficiently. Further, when the triboelectric charge amount is low, toner scattering also occurs. In addition, the ability to maintain electrostatic charge is lacking, and the triboelectric charge amount decreases as the number of copies increases, or if it becomes too high, good image density cannot be maintained.

Further, when the charge control agent is added to the toner, if the dispersibility in the resin is poor, the triboelectric charge amount of the toner becomes non-uniform and fogging is likely to occur. When the charge control agent easily contaminates the sleeve or the carrier, the triboelectric charge amount may decrease as the number of copies increases.

Further, since a large amount of the charge control agent is present on the toner surface, the environmental characteristics of the charge control agent itself have a great influence on the environmental characteristics of the toner.

An object of the present invention is to provide a toner for solving the above problems.

[0013]

A feature of the present invention is that the toner contains an amidine compound or a 1,4-diaryl-1,2,3,4-tetrahydropyridine derivative as a charge control agent.

As a compound similar to the amidine compound used in the same manner, there is a guanidine derivative.
Nos. 1-248060 and JP-A-3-133950, the structure of which is different from that of the N, N'-diarylbenzamidine derivative of the present invention, and the toner using the amidine compound of the present invention as a charge control agent. It is not known to contain.

A high charge amount can be obtained by adding the amidine compound of the present invention to the toner. In addition, the charging speed is high, the stability of the amount of charge at the start-up is good, and the environmental stability is excellent. Also, it is well dispersed in the resin, and there is little sleeve contamination and carrier contamination. Further, it can be used in combination with a magnetic material.

The N, N'-diarylbenzamidine derivative of the present invention can be synthesized by the following method. N-phenylbenzamide 9.86 g, phosphorus pentachloride 10.4 g 11
After operating for 2 hours at 0 to 130 ° C., 4.0 g of pyridine and 4.7 g of aniline were added dropwise at the same temperature. And
After stirring at 160 ° C. for 30 minutes, the mixture was poured into water, the precipitated crystals were filtered and recrystallized from ethanol to obtain the target compound.

Specific examples of the amidine compound that can be used in the toner of the present invention are shown below. This is a typical example in consideration of ease of handling and the like, and does not limit the toner of the present invention at all.

[0018]

[Chemical 2] Known examples of pyridine compounds include US Pat. No. 4,486,620 and US Pat. No. 4,792,513.
, U.S. Pat. No. 4,604,338, JP-B-64-10824, JP-B-2-44217, JP-A-1-136166, and JP-A-1-730.
There is publication 55. However, both are pyridinium salts and have different molecular structures. In addition, Japanese Patent Publication No.
In 1674, a pyridine derivative is disclosed.
Although this compound itself is colorless, it is used as light-transmitting particles for yellow image formation, more specifically, as a sublimable color former, and its usage form is different from that of the present invention.

1,4-diaryl-1,2, of the present invention
The inclusion of 3,4-tetrahydropyridine derivatives in toners is novel. As a performance as a charge control agent,
It is characterized by having a sufficient amount of charge itself and also increasing the charging speed of the toner. Further, it is well dispersed in the binder resin with the pigment, and is also excellent in charge retention ability. Further, it can be used in combination with a magnetic material.

1,4-diaryl-1,2 of the present invention,
As a method for synthesizing the 3,4-tetrahydropyridine derivative, a synthesis example of 1,4,5,6-tetrahydro-1,4,6-triphenylpyridine will be described.

1,4-Diphenyl-1-azabutadiene (10.4 g), styrene (5.2 g) and anhydrous aluminum chloride (0.05 g) were put in a glass sealed tube, placed in an oil bath at 200 ° C., occasionally shaken and left for 3 hours. did. After allowing to cool, the reaction product was dissolved in toluene, the insoluble material was filtered off, washed with water, concentrated, and recrystallized from ethanol to synthesize the target compound.

Specific examples of the 1,4-diaryl-1,2,3,4-tetrahydropyridine derivative which can be used in the toner of the present invention are shown below. This is a typical example in consideration of ease of handling and the like, and does not limit the toner of the present invention at all.

[0023]

[Chemical 3] The amidine compound of the present invention or 1,4-diaryl-1,
As a method of incorporating the 2,3,4-tetrahydropyridine derivative into the toner, there are a method of adding it inside the toner and a method of adding it externally. 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 production method including the dispersion method, and is not uniquely limited. However, when internally added, it is preferably 0.1 to 100 parts by weight of the binder resin.
It is used in an amount of 10 parts by weight, more preferably 0.5 to 5 parts by weight. When added externally, it is preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the resin. In the case of external addition, it is particularly preferable to fix or bury the particles near the surface of the fine particles of the binder resin and the colorant by mechanical impact.

The amidine compound of the present invention or 1,4
The -diaryl-1,2,3,4-tetrahydropyridine derivative can also be used in combination with other charge control agents.

On the other hand, as the resin for forming the toner particles used in the present invention, for example, a homopolymer of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene and the like, or a substitution product thereof; styrene-p. -Chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-
Acrylic ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer Styrene-based copolymers such as polymers, styrene-vinyl methyl ketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-acrylonitrile-indene copolymers; polyvinyl chloride, phenolic resins, natural Modified phenol resin, natural resin, modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, terpene Fat, coumarone-indene resins, and petroleum resins.

A crosslinked styrene copolymer is also a preferred binder resin. Examples of the comonomer for the styrene monomer of the styrene copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate,
2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate,
A monocarboxylic acid having a double bond such as acrylonitrile, methacrylonitrile, acrylamide, or a substituted product thereof; for example, maleic acid, butyl maleate,
Dicarboxylic acids having a double bond such as methyl maleate and dimethyl maleate and their substituted compounds; vinyl esters such as vinyl chloride, vinyl acetate and vinyl benzoate; such as ethylene, propylene and butylene Ethylenic olefins; vinyl ketones such as vinyl methyl ketone and vinyl hexyl ketone; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; Used more than one. Here, as the cross-linking agent, a derivative having two or more polymerizable double bonds is mainly used, and examples thereof include aromatic divinyl derivatives such as divinylbenzene and divinylnaphthalene; for example, ethylene glycol diacrylate and ethylene glycol diethylene. Methacrylate, 1,3-
A carboxylic acid ester having two double bonds such as butanediol dimethacrylate; a divinyl derivative such as divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone; and a derivative having three or more vinyl groups; Used as.

When the pressure-fixing method is used, a binder resin for pressure-fixing toner can be used. For example, polyethylene, polypropylene, polymethylene, polyurethane elastomer, ethylene-ethyl acrylate copolymer, ethylene-acetic acid. Examples thereof include vinyl copolymers, ionomer resins, styrene-butadiene copolymers, styrene-isoprene copolymers, linear saturated polyesters and paraffins.

External addition of silica to a toner containing the amidine compound or the 1,4-diaryl-1,2,3,4-tetrahydropyridine derivative of the present invention is a preferable mode. The amount of silica used at that time is not uniquely limited, but is preferably 0.05 to 10 parts by weight, and more preferably 0.2 to 100 parts by weight of the toner.
It is used in the range of up to 5 parts by weight.

As the silica used in the present invention, a fine triboelectric silica fine powder is preferable. As such silica fine powder, silica fine powder produced by a dry method and 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 halogen derivative. For example, in a method utilizing a thermal decomposition oxidation reaction of silicon tetrachloride gas in oxygen hydrogen, the basic reaction formula is as follows.

SiCl ₄ + 2H ₂ + O ₂ → SiO ₂ + 4HCl In this manufacturing process, for example, aluminum chloride,
Alternatively, it is possible to obtain a composite fine powder of silica and another metal oxide by using another metal halogen derivative such as titanium chloride together with a silicon halogen derivative, and these are also included.

On the other hand, as the method for producing the silica fine powder used in the present invention by the wet method, various conventionally known methods can be applied. For example, if sodium silicate is decomposed by an acid, and is represented by a general reaction formula (hereinafter, the reaction formula is omitted), Na ₂ O.XSiO ₂ + 2HCl + H ₂ O → SiO ₂ .nH
₂ O + 2NaCl Other decomposition of sodium silicate with ammonia salts or alkali salts, method of generating alkaline earth metal silicate from sodium silicate, and then decomposing with acid to obtain silicic acid, ion exchange of sodium silicate solution There are a method of making silicic acid by a resin, a method of using natural silicic acid or a silicate, and the like.

The silica fine powder referred to here is anhydrous silicon dioxide (silica), other than aluminum silicate, sodium silicate, potassium silicate, magnesium silicate,
Any silicate such as zinc silicate can be applied.

Among the above silica fine powders, those having a specific surface area by nitrogen adsorption of 30 m ² / g or more (particularly 50 to 400 m ² / g) measured by the BET method give good results.

The positively chargeable silica fine powder is obtained by treating the above-mentioned untreated silica fine powder with a silicone oil having an organo group having at least one nitrogen atom in the side chain, or a nitrogen-containing silane. There is a method of treating with a coupling agent, or a method of treating with both of them.

In the present invention, positively charged silica means
It has a positive charge to the iron powder carrier when measured by the blow-off method.

Examples of such treating agents include aminopropyltrimethoxysilane, aminopropyltriethoxysilane, dimethylaminopropyltrimethoxysilane,
Diethylaminopropyltrimethoxysilane, dipropylaminopropyltrimethoxysilane, dibutylaminopropyltrimethoxysilane, monobutylaminopropyltrimethoxysilane, dioctylaminopropyltrimethoxysilane, dibutylaminopropyldimethoxysilane, dibutylaminopropylmonomethoxysilane, dimethyl There are aminophenyltriethoxysilane, trimethoxysilyl-γ-propylphenylamine, trimethoxysilyl-γ-propylbenzylamino and the like. Furthermore, as the nitrogen-containing heterocycle, those having the above-mentioned structure can be used. As an example, trimethoxysilyl-γ
-Propylpiperidine, trimethoxysilyl-γ-propylmorpholine, trimethoxysilyl-γ-propylimidazole and the like.

The amount of the treated silica fine powder applied is 0.01 to 20% based on the weight of the developer, and the effect is excellent, and particularly preferably 0.03 to 5% is excellent. It exhibits positive triboelectricity with stability. To describe a preferable mode of addition, it is preferable that 0.01 to 3% by weight of the treated silica fine powder with respect to the weight of the developer is attached to the surface of the toner particles.

The silica fine powder used in the present invention is
If necessary, it may be treated with a treating agent such as a silane coupling agent or a silicon derivative, and a known method is used as well, and the treating agent which reacts or physically adsorbs with the silica fine powder is used. As such a treating agent, for example, hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane. , Bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyl Dimethoxysilane, diphenyldiethoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane, 1,
There are 3-diphenyltetramethyldisiloxane, dimethylpolysiloxane having 2 to 12 siloxane units per molecule, and each of the terminally located units has a hydroxyl group bonded to Si. These are used alone or in a mixture of two or more.

The toner for developing an electrostatic charge image of the present invention can also be used as a magnetic toner by containing a magnetic material. Magnetic materials used include magnetite and γ-
Iron oxides such as iron oxides, ferrites, and iron-rich ferrites;
Metals such as iron, cobalt and nickel, or these metals and metals such as aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten and vanadium. And alloys thereof and mixtures thereof. These magnetic materials have an average particle size of 0.
1 to 1 μm, preferably 0.1 to 0.5 μm is desirable, and the amount contained in the magnetic toner is 40 to 150 parts by weight, preferably 60 to 120 parts by weight with respect to 100 parts by weight of the binder resin component. It is a department.

As the magnetic toner using the charge control agent of the present invention, a toner having a weight average particle diameter of 3 to 15 μm can be used. In particular, 12 to 60% by number of magnetic toner particles having a particle size of 5 μm or less are contained, 1 to 33% by number of magnetic toner particles having a particle size of 8 to 12.7 μm are contained, and a particle size of 16 μm or more. Magnetic toner particles are 2.
It is contained in an amount of 0% by weight or less and the weight average particle diameter of the magnetic toner is
From the standpoint of development characteristics, it is more preferably 10 μm.

The particle size distribution of the toner can be measured by various methods, but in the present invention, it is suitable to use a Coulter counter. That is, a Coulter Counter TA-II type (manufactured by Coulter) is used as a measuring device, an interface (manufactured by Nikkaki) for outputting number distribution and volume distribution, and a CX-1 personal computer (manufactured by Canon) are connected, and an electrolytic solution Prepares an approximately 1% NaCl aqueous solution using primary sodium chloride. For example, ISOTON (registered trademark) -II (manufactured by Coulter Scientific Japan) can be used. As a measuring method, a surfactant, preferably 0.1 to 5 ml of an alkylbenzene sulfonate as a dispersant is added to 100 to 150 ml of the electrolytic aqueous solution, and 2 to 2 of measurement samples are further added.
Add 0 mg. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and 100 μm as an aperture with the Coulter Counter TA-II type.
The volume and the number of the toner were measured using the m-aperture to calculate the volume distribution and the number distribution of the particles of 2 to 40 μm. Then, the weight-based weight average diameter (D ₄ ) obtained from the volume distribution according to the present invention (the median value of each channel is a representative value for each channel), and the weight-based coarse powder amount obtained from the volume distribution (20.2 μm or more), and the number-based fine powder number (6.35 μm or less) determined from the number distribution was determined.

Further, 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, iron powder, ferrite powder, magnetic powder such as nickel powder, glass beads, and the like, and the surface thereof is treated with a resin or the like. What you have done is listed. Further, 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, silicone resin, fluorine-containing resin, A polyamide resin, an ionomer resin, a polyphenylene sulfide resin, or the like, or a mixture thereof can be used.

Further, the toner of the present invention may be mixed with an additive, if necessary. Examples of the additive include a lubricant such as zinc stearate, an abrasive such as cerium oxide and silicon carbide, a fluidity imparting agent such as aluminum oxide, an anti-caking agent, or a conductivity imparting agent such as carbon black and tin oxide. I have an agent.

Fluorine-containing polymer fine powders such as polyvinylidene fluoride fine powders are also preferable additives from the viewpoints of fluidity, abrasivity and charge stability.

For the purpose of improving releasability at the time of heat roll fixing, wax-like substances such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, carnauba wax, sazol wax and paraffin wax are added in an amount of 0.5-5. It is also one of the preferred embodiments of the present invention to add about wt% to the toner.

In the production of the toner according to the present invention, the toner constituent materials as described above are thoroughly mixed by a ball mill or other mixing machine, and then thoroughly kneaded by using a heat kneader such as a hot roll kneader or an extruder. A method of obtaining a toner by mechanical pulverization and classification after cooling and solidification is preferable. Another method is to obtain the toner by dispersing constituent materials in a binder resin solution and then spray-drying; or an emulsified suspension prepared by mixing a predetermined material with a monomer constituting the binder resin. And then polymerizing to obtain a toner;
Alternatively, in a so-called microcapsule toner including a core material and a shell material, a method in which a predetermined material is contained in the core material or the shell material, or both of them can be applied.

Further, if desired, desired additives can be sufficiently mixed with a mixer such as a Henschel mixer to produce the toner according to the present invention.

The toner of the present invention can be used by any conventionally known means for development for developing an electrostatic charge image in electrophotography, electrostatic recording, electrostatic printing and the like.

[0049]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.
All parts in the following formulations are parts by weight.

Example 1 Styrene / butyl methacrylate copolymer 100 parts Exemplified compound (1) 3 parts The above materials were well mixed by a blender and then kneaded by a twin-screw kneading extruder set at 150 ° C. The obtained kneaded product was cooled, coarsely pulverized by a cutter mill, then finely pulverized by a fine pulverizer using a jet stream, and the finely pulverized powder obtained was classified by a fixed wall type air classifier. The classified powder was purified.

Further, the classified powder thus obtained is strictly classified at the same time by using a multi-division classifier utilizing the Coanda effect (Elbow Jet classifier manufactured by Nittetsu Mining Co., Ltd.) to precisely remove ultrafine powder and coarse powder at a weight average particle diameter of 12 μm. A fine powder of The obtained fine powder and iron powder carrier were mixed at a ratio of 5:95 (using a Turbula mixer), and the triboelectric charge amount was measured.

The triboelectrification amount is measured by using the apparatus shown in FIG. 1 as follows.

A sample (a mixture of toner and carrier particles shaken for a certain period of time) is placed in a metal measuring container 2 having a conductive screen 3 of 500 mesh at the bottom (the size can be appropriately changed so that carrier particles do not pass). Put on the lid 4 made of metal. At this time, the total weight of the measuring container 2 is weighed and W ₁
(G). Next, in the suction device 1 (at least the portion in contact with the measurement container 2 is an insulator), suction is performed from the suction port 7, the air volume control valve 6 is adjusted, and the pressure of the vacuum gauge 5 is adjusted to 70 mm.
Hg. In this state, suction is sufficiently performed (for about 1 minute) to remove the toner by suction. The potential of the electrometer 9 at this time is V (volt). Where 8 is a condenser,
Let the capacity be C (μF). Further, the weight of the entire measuring container after suction is weighed to obtain W ₂ (g). The triboelectric charge amount is calculated by the following formula.

Q (μc / g) = C · V / (W ₁ -W ₂ ) Table 1 shows the measurement results of the triboelectric charge amount obtained as described above.

Example 2 Styrene / butyl methacrylate copolymer 100 parts Exemplified compound (2) 3 parts Using the above materials, a fine powder having a weight average particle diameter of 12 μm was obtained in the same manner as in Example 1 and the same method. The triboelectric charge amount was measured with. The results are shown in Table 1.

Example 3 Styrene / butyl methacrylate copolymer 100 parts Exemplified compound (3) 4 parts Using the above materials, a fine powder having a weight average particle diameter of 12 μm was obtained in the same manner as in Example 1 and the same method. The triboelectric charge amount was measured with. The results are shown in Table 1.

[0057]

[Table 1] Example 4 Styrene / butyl acrylate copolymer 100 parts Magnetic iron oxide 80 parts Low molecular weight propylene / ethylene copolymer 4 parts Exemplified compound (1) 3 parts The same materials as in Example 1 were used, and the weight average particle diameter was determined. 8.
A black fine powder of 5 μm was obtained. To 100 parts of this black fine powder, silica treated with amino-modified silicone oil (200
m ² / g) was added in an amount of 0.6 part and mixed with a Henschel mixer to obtain a positively chargeable one-component magnetic toner.

The obtained magnetic toner was subjected to a copying test on 10,000 sheets with a commercially available electrophotographic copying machine NP-4835 (manufactured by Canon Inc.). As a result, a good image with an image density of 1.32 and less fog was obtained. Was obtained. After copying 20,000 sheets, the image density was 1.30 and no decrease in density was observed.

Example 5 Styrene / butyl methacrylate copolymer 100 parts Copper phthalocyanine blue pigment 5 parts Low molecular weight polypropylene wax 3 parts Exemplified compound (2) 4 parts As in Example 1, weight average particle diameter of 8.2 μm A dark blue fine powder was obtained. To 100 parts of the obtained blue fine powder, 1.0 part of dry silica (200 m ² / g) treated with a silane coupling agent having an amino group was added and mixed with a Henschel mixer to give a positively chargeable toner.

Next, a developer was prepared by mixing 5 parts of the obtained toner with 100 parts of a fluorine-acryl-coated ferrite carrier having an average particle size of 60 to 80 μm. The developer was tested for copying by using a commercially available color electrophotographic copying machine (trade name CLC-200, manufactured by Canon Inc.) with a modified machine in which the OPC photosensitive drum was replaced with an amorphous silicon drum.

A blue image having an image density of 1.33 was obtained.
An image with a density of 1.35 was obtained even after copying 8,000 sheets, and no decrease in density was observed.

Example 6 Styrene / butyl methacrylate copolymer 100 parts Carbon black 4 parts Low molecular weight polypropylene wax 2 parts Exemplified compound (1) 5 parts Using the above materials, in the same manner as in Example 1, weight average particle diameter A fine powder of 8.1 μm was obtained. Obtained black fine powder 10
0.8 part of positively chargeable silica was mixed with 0 part, and a copy test was conducted in the same manner as in Example 5.

Under the environment of 23 ° C./60%, the initial image had a high density of 1.33. Further, the density was 1.30 after copying 10,000 sheets, and no decrease in density was observed. Also,
The initial image density is 1. even under the environment of 30 ° C / 80%.
35, and stable images were obtained even after copying 10,000 sheets. Further, even under an environment of 15 ° C./20%, a stable density was similarly obtained from the initial image.

Comparative Example 1 A toner was obtained in the same manner as in Example 4 except that 2 parts of N, N′-diphenylguanidine was used instead of 3 parts of the exemplified compound (1) used in Example 4. Using this toner, a copy test was conducted in the same manner as in Example 4.

The initial image density is only 1.09 and is 400
The image density finally reached 1.29 on the first sheet, and the image density was slow to rise. After copying 20,000 sheets, the image density was 1.25, which was relatively stable.

Comparative Example 2 Development was carried out in the same manner as in Example 5 except that 4 parts of N, N'-bis (p-methylphenyl) guanidine was used instead of 4 parts of the exemplified compound (2) used in Example 5. Get the agent,
A copy test was performed.

As a result of the test under the environment of 23 ° C./60%, the initial image density was 1.18, the density after copying 10,000 sheets was 1.26, and rising of the image density was recognized.
Also, in the environment of 30 ° C / 80%, scattering occurs from the beginning, and in the environment of 15 ° C / 20%,
As in the case of 23 ° C./60%, the slow rise of the image density was noticeable.

Example 7 Styrene / butyl methacrylate copolymer 100 parts Exemplified compound (5) 2 parts Using the above materials, a fine powder having a weight average particle diameter of 12 μm was obtained in the same manner as in Example 1 and the same method. The triboelectric charge amount was measured with. The results are shown in Table 2.

Example 8 Styrene / butyl methacrylate copolymer 100 parts Exemplified compound (6) 2 parts Using the above materials, a fine powder having a weight average particle diameter of 12 μm was obtained in the same manner as in Example 1 and the same method. The triboelectric charge amount was measured with. The results are shown in Table 2.

Example 9 Styrene / butyl methacrylate copolymer 100 parts Exemplified compound (7) 3 parts Using the above materials, a fine powder having a weight average particle diameter of 12 μm was obtained in the same manner as in Example 1 and the same method. The triboelectric charge amount was measured with. The results are shown in Table 2.

[0071]

[Table 2] Example 10 Styrene / butyl acrylate copolymer 100 parts Magnetic iron oxide 80 parts Low molecular weight propylene / ethylene copolymer 4 parts Exemplified compound (5) 2 parts In the same manner as in Example 1, the weight average particle diameter was obtained. 8.
4 μm black fine powder was obtained. To 100 parts of this black fine powder, silica treated with amino-modified silicone oil (200
0.4 part of m ² / g) was added and mixed with a Henschel mixer to obtain a positively chargeable one-component magnetic toner.

When a copy test was performed on 10,000 sheets in the same manner as in Example 4, a good image with an image density of 1.35 and less fog was obtained. After copying 20,000 sheets, an image with an image density of 1.31 was obtained, and no decrease in density was observed.

Example 11 Styrene / butyl methacrylate copolymer 100 parts Copper phthalocyanine blue pigment 5 parts Low molecular weight polypropylene wax 2 parts Exemplified compound (6) 2 parts The same as in Example 1 except that the weight average particle diameter was 8.2 μm. A dark blue fine powder was obtained. To 100 parts of the obtained blue fine powder, 0.6 part of dry silica (200 m ² / g) treated with a silane coupling agent having an amino group was added and mixed with a Henschel mixer to obtain a positively chargeable toner. .

When a copying test was conducted in the same manner as in Example 5, the image density at the initial stage was 1.34, and the image density of 1.32 was obtained even after copying 10,000 sheets. There was no ghost and a good image could be maintained.

Example 12 Styrene / butyl methacrylate copolymer 100 parts Carbon black 4 parts Low-molecular-weight polypropylene wax 2 parts Exemplified compound (7) 4 parts Using the above materials, in the same manner as in Example 1, a weight average particle diameter was obtained. A fine powder of 8.2 μm was obtained. Obtained black fine powder 10
As in Example 1, 0 part was mixed with 0.5 part of positively chargeable silica to obtain a toner. Then, a copy test was conducted in the same manner as in Example 5.

The initial image had a high density of 1.32, and the density was 1.34 even after copying 10,000 sheets, and the density did not decrease and the density was stable.

Comparative Example 3 A developer was obtained in the same manner as in Example 11 except that 4 parts of a quaternary ammonium salt was used instead of 2 parts of the exemplified compound (6) used in Example 11.

Using this toner, an image was obtained in the same manner as in Example 11. When the initial image density was 1.30, fogging occurred, and after copying 20,000 sheets, the image density was 1.
It has dropped to 19.

[0079]

As described above, when the toner of the present invention is used,
A sufficiently high and stable charge amount is maintained. Further, the rise of triboelectrification of the toner is also good. Therefore, the amidine compound of the present invention or 1,4-diaryl-1,2,2,
When a toner containing a 3,4-tetrahydropyridine derivative is used, a high-density good image can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic view of a triboelectric charge measuring device.

Claims (3)

[Claims] 1. A toner for developing an electrostatic image, comprising at least an amidine compound. 2. An electrostatic charge image developing toner comprising at least an N, N′-diarylbenzamidine derivative represented by the following general formula (I). [Chemical 1] (However, R ¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an amino group, or an alkoxy group. R ² and R ³ are hydrogen atoms, an alkyl group having 1 to 8 carbon atoms, an aralkyl group,
It is an amino group, an alkoxy group, or an aryl group, and they may be the same or different. k, l, and m are integers of 1 to 3. ) 3. At least 1,4-diaryl-1,
A toner for developing an electrostatic charge image, which comprises a 2,3,4-tetrahydropyridine derivative.