JPS63138355A - Toner for developing electrostatic charge image - Google Patents

Abstract

PURPOSE:To permit the development and transfer faithfuly to a latent image, to maintain an initial characteristic even after continuous use for a long period of time and to prevent flocculation of a toner and change in the electrostatic charge characteristic thereof by incorporating a binder resin, coloring agent and specific compd. into the toner. CONSTITUTION:This toner of electrophotography is used for development of the electrostatic charge image and contains at least the binder resin, the coloring agent and the compd. expressed by formula [I]. In formula, a denotes a compd. residue having a phenolic group, R<1> denotes methylene group or ethylene group, R<2>, R<3> group of 1-8C or cyclic (including heterocyclic) aralkyl group, R<2> and R<3> may combine to form a ring. n1 Denotes 0 or 1, n2 denotes 1-400 number. The development and transfer faithful to the latent image are thereby permitted and in addition, the initial characteristic is maintained even after the long-period continuous use. The developer which is free from the flocculation of the toner and the change in the electrostatic charge characteristic thereof is thereby obtd.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a toner for developing electrostatic images, and more specifically, it is used for developing electrostatic images in electrophotography, electrostatic recording, electrostatic printing, etc. The invention relates to toner.

[Conventional technology and problems]

Conventional electrophotographic methods include uniformly charging a photoconductive insulating layer, then exposing the layer to light, as described in U.S. Pat. Forms an electrostatic latent image by dissipating the charge on the exposed area,
Furthermore, the electrostatic latent image is visualized by attaching a colored, electrically charged fine powder called toner (developing process), and the resulting visible image is transferred to a transfer material such as transfer paper ( (transfer step), and permanent fixation (fixing step) by heating, pressure or other suitable fixing methods.

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. Two-component development methods include, depending on the type of system for transporting the toner, the magnetic brush method using a magnetic powder carrier that uses magnetic force, the cascade method using a somewhat coarse bead carrier, and the cascade method using a somewhat coarse bead carrier, and glass fibers instead of carrier particles. There is a fur brush method using

As toners applied to these developing methods, fine powders in which colorants such as dyes and pigments are dispersed in natural or synthetic thermoplastic resins have been used. For example, a binder resin such as polystyrene or polyester containing a colorant and various additives described below may be dispersed in a 1-30μ
Finely pulverized particles are used as toner.

As magnetic toners mainly used in one-component developers, those containing magnetic particles such as magnetite are used. On the other hand, 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. Furthermore, the toner is required to have a uniform positive or negative charge depending on the polarity of the electrostatic latent image to be developed.

In order to cause the toner to have a desired charge, it is also possible to utilize the triboelectricity of the carrier and its surface material or the resin that is a component of the toner, but this method alone results in a small chargeability of the toner or a rapid charging process. Since the desired amount of charge is not reached, the image obtained by development tends to be foggy and unclear. Therefore, in order to quickly impart a desired amount of triboelectric charge to the toner, dyes, pigments, and even charge control agents that can impart chargeability are added to the toner.

For positive charging, electron-donating dyes such as nigrosine dyes are effective, and for negative toners, electron-accepting organic complexes such as oil-soluble metal-containing dyes are widely used.

Since nigrosine dyes do not have good dispersibility in resins, they are often used after modification with oleic acid or stearic acid.

In addition, for regular toner, Iosol Bra 2,
For negative toners, there are aliphatic amines, quaternary ammonium salts, compounds of quaternary ammonium salts and higher alkyl groups, Feschwaltz HOW, Sudan Cheekschwartz BBC, Brilliant Spirit, Zabonschwartz x1 Solvent Red, etc. , colloidal silica, aliphatic metal salt, monoazo dye metal complex salt, chlorinated paraffin, chlorinated polyester, Subiron black (manufactured by Odugaya Chemical Co., Ltd.), Valifast black (Valifast)
Black (manufactured by Orient Chemical Co., Ltd.), Chromogen Schwarz ETCO, Azooilplan, etc., but in general, copper phthalocyanine is aminated and substituents are introduced, or copper phthalocyanine containing a nitro group is also added. quantity is used.

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.

In the case of color toners, since colored dyes cannot be used, colorless charge control agents are being considered in addition to utilizing the frictional charging properties of resins described above.

For example, quaternary ammonium-based products, dehydrated condensates of ortho-position amines and dicarboxylic acids, vinylpyridine, vinylpyrazine, etc., are used, but none of them have superior overall performance to dye-pigment-based products, and are still unsatisfactory. However, in most cases dyes are used.

These are usually added to a thermoplastic resin, hot-melted and kneaded, and then finely pulverized and adjusted to an appropriate particle size as necessary before use.

However, many of these dyes used as charge control agents have complex structures, inconsistent properties, and poor stability. In addition, decomposition during thermal kneading, mechanical shock, friction,
It is easily decomposed or deteriorated due to changes in temperature and humidity conditions, and tends to cause a phenomenon in which charge controllability is deteriorated.

Therefore, if a toner containing these dyes together with a charge control agent is used in a copying machine to develop it, the charge control agent may decompose or change in quality as the number of copies increases, leading to deterioration of the toner during durability. be.

Furthermore, since it is extremely difficult to uniformly disperse these charge control agents in thermoplastic resins, they pose the fatal problem of causing differences in the amount of frictional charge between toner particles obtained by pulverization. have. For this reason, various methods have been used to achieve more uniform dispersion. For example, basic nigrosine dyes are used by forming salts with higher fatty acids in order to improve their compatibility with thermoplastic resins, but unreacted fatty acids or salt dispersion products are often exposed on the toner surface. This contaminates the carrier or toner carrier, causing a decrease in the fluidity of the toner, fogging, and a decrease in 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 the charge control agent powder and the resin powder are mechanically pulverized and mixed in advance and then hot melt-kneaded. However, the inherent poor dispersion cannot be avoided, and it is still not possible to obtain sufficient charge uniformity for practical use.Therefore, at present, a long-life developer has not been completed.

Furthermore, most of the substances generally known as charge control agents have chromatic or dark colors, and there is a problem in that they cannot be incorporated into a developer with a desired vivid chromatic color.

Furthermore, many charge control agents are hydrophilic, and due to poor dispersion in these resins, they are exposed on the toner surface when they are melted and kneaded and then crushed. Therefore, when the toner is used under high-temperature conditions, it has the disadvantage that a good quality image cannot be obtained because these charge control agents are hydrophilic.
゛In this way, when conventional charge control agents are used in toner, the electric charge generated on the toner particle surface during the process of causing frictional charging between toner particles or between toner and carrier, etc. Variations in the amount may occur, resulting in development fog,
Problems such as toner scattering and carrier contamination are likely to occur. Furthermore, this failure becomes a noticeable phenomenon when copying is repeated many times, resulting in a result that is practically unsuitable for copying machines.

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

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

Furthermore, when conventional charge control agents are used in toners, many of them greatly affect the thermal melting properties of the toners and reduce fixing performance. It is also seen that high temperature offset performance is deteriorated, the quality of the copied image is deteriorated, the clinging of the transfer paper to the roller is increased, and the durability of the roller is shortened due to toner adhesion to 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, no one has yet been found that is comprehensively satisfactory for practical use.

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

Another object of the present invention is to stabilize the triboelectric charge amount of the toner in a process that generates triboelectrification between toner particles or between a toner and a carrier, and to quickly build up the triboelectric charge. The objective is to provide a developer that can control the amount of charge suitable for the system.

Still another object is to develop the latent image faithfully and to use a developer for transfer, that is, toner adhesion in the background area during development, that is, no fogging or toner scattering around the edges of the latent image. To provide a developer capable of obtaining high image density and good halftone reproducibility.

Still another object is to provide a developer that maintains its initial characteristics even when the developer is used continuously for a long period of time, and that has good toner consumption efficiency without toner aggregation or change in charging characteristics.

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

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

Yet another object is to provide a bright chromatic developer.

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

Still other purposes are to prevent the electrostatic latent image surface from becoming dirty or abraded;
To provide a developer that does not cause scratches and is easy to clean.

[Means for solving problems]

The present invention relates to an electrophotographic toner used for developing an electrostatic image, which comprises at least a binder resin, a colorant, and the following general formula (
The present invention relates to an electrostatic image developing toner characterized by containing a compound represented by T).

(However, A is a compound residue having a phenol group, R1 is a methylene group or an ethylene group, R2 and R3 are an alkyl group having 1 to 8 carbon atoms, an aryl group, an alkenyl group, an aralkyl group, or a cyclic (including heterocycle) Indicates an alkyl group, R2
and R3 may be combined to form a ring. nl is O or 1
, R2 represents a number from 1 to 400. ) Specific examples of the compound residue having a phenol group represented by A in the above formula include the residues of the compounds shown below.

Alkylphenols such as phenol, cresol, ethylphenol, n-propylphenol, isopropylphenol, n-butylphenol, 5ec-butylphenol, tert-butylphenol, 5ec-amylphenol, isopentylphenol, hexylphenol, octylphenol; chlorophenol, bromophenol, etc. halogenated phenols; such as p-cyclohexylphenol, fenylphenol, tolylphenol; 2,3-xylenol, 3,4-xylenol, 2,5-xylenol;
2.3-diethylphenol, 3.4-diethylphenol, 2,5-diethylphenol, 2.3-diisopropylphenol, 3,4-diisopropylphenol, 2゜5-diisopropylphenol, 2.3-dichlorophenol, 3 , 4-dichlorophenol; bisphenol A1 bisphenol F, 1
, 12.2-tetrakis(4-hydroxyphenyl)ethane, 4.4'-(1,4-phenylenebis(1-methylethylidene))hisphenol, α, cx', c
x”-tris(4-hydroxyphenyl)-L3,5
-) polyphenols such as lyisopropylbenzene; and polyhydric phenols such as catechol, resorcinol, hydroquinone, phloroglycin, 1,2.4-) lyhydroxybenzene, and novolac-type polyphenols obtained by condensing the various phenols mentioned above with formalin. , phenolic polymers such as copolymers of p-hydroxystyrene and acrylic esters.

Representative examples of the compound represented by the above general formula (1,) include the following.

CHff C)13 CH3CH3CH3 n=2.0 p++pz+p*=3・0 l3 t CaHq t CaHqOI y=50 j=160 In the present invention, the compound represented by the above general formula (1) is a solid at least at room temperature. Those having a softening point of 50° C. or more are more preferable. Compounds that are liquid at room temperature or have a low softening point bleed out on the surface of the powder toner during long-term storage or use, causing electrical deterioration and causing filming on the developer and photoreceptor. This is because the image changes depending on the situation.

Methods for incorporating the compound represented by the general formula CI) into the toner include a method of adding it inside the toner 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 not uniquely limited. Although not necessarily limited to 100 parts by weight of the binder resin, it is preferably used in an amount of 0.1 to 20 parts by weight (more preferably 0.5 to 10 parts by weight).

When externally added, the softening point of the compound is preferably 100°C or higher, the particle size is preferably 10p or less, and the amount added is preferably 0.01 to 10 parts by weight per 100 parts by weight of the resin.

Further, a conventionally known charge control agent may be used in combination with the charge control agent of the present invention, or a plurality of charge control rules of the present invention may be used in combination.

Colorants used in the present invention include carbon black, lamp black, iron black, ultramarine blue, nigrosine dye, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa Yellow G10-Damine 6G, lake,
Calco oil blue, chrome yellow, quinacridone,
Any conventionally known dyes and pigments such as benzidine yellow, rose bengal, triallylmethane dyes, monoazo dyes, and disazo dyes and pigments can be used alone or in combination.

The binder resin used in the present invention includes polystyrene,
Monopolymers of styrene and its substituted products such as poly-p-chlorostyrene and polyvinyltoluene; styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene Copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene -Ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer i1, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer Polymethyl Methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyurethane, polyamide, epoxy resin, polyvinyl butyral, polyacrylic resin, rosin, modified rosin, terpene resin, phenolic resin, aliphatic or fatty resin Examples include cyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, and paraffin waxes, which can be used alone or in combination.

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

All known carriers can be used in the present invention, such as magnetic powders such as iron powder, ferrite powder, and nickel powder, glass beads, etc., and carriers whose surfaces have been treated with resin, etc. Examples include powder obtained by melt-kneading a magnetic material described below with a binder resin and pulverizing the mixture.

Furthermore, the toner of the present invention can further 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; gold i such as iron, cobalt, and nickel; and aluminum, cobalt, copper, lead, magnesium, and tin of these metals. , zinc, antimony,
Examples include alloys of metals such as beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, and vanadium, and mixtures thereof.

These magnetic materials preferably have an average particle size of about 0.1 to 2 μm, 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 30 to 150 parts by weight.

Further, the toner of the present invention may be mixed with additives as necessary. Examples of additives include lubricants such as Teflon and zinc stearate, abrasives such as cerium oxide and silicon carbide, flow agents such as colloidal silica, titanium oxide, and aluminum oxide, anti-caking agents, and carbon. Examples include conductivity imparting agents such as black and tin oxide, and fixing aids such as low molecular weight polyethylene and low molecular weight polypropylene.

To prepare the toner for developing an electrostatic image according to the present invention, a charge control agent represented by the general formula CI) is added to a vinyl or non-vinyl thermoplastic resin, a pigment or dye as a coloring agent, and optionally a charge control agent represented by the general formula CI). Magnetic materials, additives, etc. are thoroughly mixed using a ball mill or other mixer, then melted and kneaded using a heat kneader such as a heated roll, kneader, or extruder to make the resins compatible with each other, and then cooled and solidified. A toner having an average particle size of 8 to 15 μm can be obtained by pulverization and classification.

Alternatively, toner particles can be obtained by dispersing the material in a binder resin solution and then spray-drying it, or by mixing a specified material with the monomers that constitute the binder resin to form an emulsified suspension, and then polymerizing the resulting toner. A method such as a polymerization toner manufacturing method that obtains can be applied.

The toners prepared by these methods can be used for developing electrostatic charge images in electrophotography, electrostatic recording, electrostatic printing, etc. by conventionally known means, and have the following advantages: It produces a certain effect.

That is, the amount of triboelectric charge of the toner particles is stable, and the amount of charge can be easily controlled. Furthermore, the toner is extremely stable, with no variation or decrease in the amount of triboelectric charge due to deterioration during use. Therefore, the above-mentioned problems such as image fogging, toner scattering, and contamination of electrophotographic photosensitive materials and copying machines are eliminated, and since the toner of the present invention is extremely excellent, for example, toner storage during storage, which has been a major drawback in the past, can be avoided. It is a toner that can withstand long-term storage without causing phenomena such as agglomeration, clumping, and low-temperature flow, and also has excellent abrasion resistance, fixing properties, and adhesive properties of toner images.

These excellent effects of the toner are further magnified when used in a repetitive transfer copying system in which charging, exposure, development, and transfer operations are successively repeated.

Furthermore, since there is no color tone disturbance caused by charge control agents, it is possible to form color images with excellent colors when used as a color electrophotographic toner.

〔Example〕

EXAMPLES The present invention will be specifically explained below with reference to 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 Carbon black (Mitsubishi"44) 10 parts Low molecular weight polypropylene wax 2 parts Compound (1) 2
After thoroughly mixing the above materials in a blender, they were kneaded with 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 jet stream, and further classified using an air classifier to obtain a fine powder with a particle size of 5 to 20μ. Ta.

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 microns.

Next, a negative electrostatic image is formed on the OPC A light body by a conventionally known electrophotographic method, and this is powder developed using the above developer using a magnetic brush method to create a toner image, which is transferred to plain paper. It was fixed by heating.

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. A significant improvement in fixing strength was also observed.

Transfer images were successively created using the above developer to examine durability, and the transferred images after so many copies were also comparable to the initial images.

Also, during the durability test, 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 so and ooo sheets, I observed the fuser and found no scratches or damage to the rollers, and almost no stains from off-cent toner. There was no.

Table 1 summarizes the image evaluation results under normal environment.

In addition, when the environmental conditions were set to 35℃ and 85%, the image density was almost the same as at room temperature, and a clear image was obtained without fogging or dropout, and the durability was so, ooo.
There was almost no change until the end. Next, when a transferred image was obtained at 15° C. and 10% low temperature and low humidity, the image density was sufficiently high, the solid black was eliminated, the image was smoothly developed and transferred, and it was an excellent image with no scattering or hollow spots. Durability was carried out under these environmental conditions, and even though copies were made continuously and intermittently, the density variation was within ±0.2 up to so and ooo 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), and development, transfer, and fixing were carried out in the same manner. I got the image.

Table 1 shows the image evaluation results under normal conditions. At room temperature, there was little fog, but the image density was as low as 1.00, and the line drawings were scattered, and the solid black was noticeably rough. Durability was investigated, and the density decreased to 0.80 when so and ooo sheets were printed.

The total amount of toner consumed up to 50,000 sheets was 20% higher than that of Example 1.

Further, during durability, after about 10,000 copies, the toner material formed a film in the form of thin stripes 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.

The transfer efficiency was also over 80% at the initial stage, but decreased to 60% after 30,000 sheets were printed.

Furthermore, during the durability test, the fixed image tended to get caught up in the fixing roller during the fixing process, and the surface of the fixing roller became conspicuous, making it difficult to remove the image from the roller. There was also a problem with toner scattering due to the large amount of dirt inside the machine.

When an image was obtained under the conditions of 35° C. and 85%, the image density was 1.35 and there was no problem, but scattering and roughness increased. Transfer efficiency was low and toner consumption increased.

When an image was obtained under the conditions of 15° C. and 10%, the image density was as low as 0.90, and there was severe loss, fogging, roughness, and transfer defects were noticeable. Continuous image output was performed, but 30
After approximately ,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 (l), and the steps of development, transfer, and
Fixation was performed and an image was obtained in the same manner.

The detailed results are shown in Table 1, and almost the same satisfactory results 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 (5) was used instead of 2 parts of compound (1), and the development, transfer, and
Fixation was performed and an image was obtained in the same manner.

The detailed results are shown in Table 1, 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 (6) was used instead of 2 parts of compound (1), and the steps of development, transfer, and
Fixation was performed and an image was obtained in the same manner.

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

Example 5 Triiron tetroxide EPT-500 (Toda Kogyo type) 60 parts Low molecular weight polypropylene wax 2 parts Compound (3)
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 was left to cool naturally, it was coarsely pulverized using a Cantermill, 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 20μ. Obtained.

This toner is used in copiers (O
As a result, as shown in Table 1, almost the same good results as in Example 1 were obtained as shown in Table 1.

Example 6 In Example 1, instead of the styrene/butyl acrylate copolymer, a polyester resin (a condensation product of polyoxyethylene bisphenol A1 polyoxypropylene bisphenol A1 terephthalic acid, trimellitic anhydride, and tetrapropenyl succinic anhydride; Ring and ball softening point 145°
A developer was obtained in the same manner as in Example 2, except that C) was used, and an image was obtained in the same manner by performing development, transfer, and fixing.

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

Comparative Example 2 A developer was obtained in the same manner as in Example 5, except that 2 parts of hensylmethyl-hexadecyl ammonium chloride was used instead of 2 parts of compound (1) in Example 1, and an image was obtained in the same manner.

Table 1 shows the image evaluation results under normal conditions. At room temperature, there was little fog, but the image density was as low as 0.90, and line drawings were also outstanding, and the solid black was noticeably rough. Durability was investigated, and the density decreased to 0.48 after 30,000 sheets.

Also, the above-mentioned filming phenomenon during durability, problems in the fixing process,
Also, the transfer efficiency and toner consumption were almost the same as in Comparative Example 1, and were unsatisfactory.

When images were obtained under conditions of 35°C and 85%, the image density was initially 1.35, which was not a problem, but after 10,000 sheets, it became 0.
It became as low as 72, and fogging, skipping, and roughness increased.
It was unusable. Transfer efficiency was also low. 1
When an image was obtained under conditions of 5° C. and 10%, the image density was as low as 0.70, and there was severe loss, fogging, roughness, and transfer omissions were noticeable.

Continuous image printing was performed, but the image density became 0.50 after 10,000 sheets, making it impractical.

Example 7 Same polyester resin as Example 6 100 parts Copper phthalocyanine blue pigment 5 parts Low molecular weight polypropylene wax 2 parts Compound (1) 2 parts The above materials were thoroughly mixed in a blender and then kneaded with two rolls heated to 150°C. did. After the kneaded material was left to cool naturally, it was roughly pulverized with a cutter mill, then pulverized with 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 20μ. Ta.

Next, 100 parts of carrier iron powder having a particle size of 50 to 80 μm was mixed with 5 parts of the fine powder to prepare a developer.

When this developer was used to produce an image in the same manner as in Example 1, a good image with a vivid blue color was obtained.

Thereafter, images were printed up to 300,000,000 sheets while replenishing toner, and good images were obtained.

Table 1 summarizes the image evaluation results under normal environment.

〔Effect of the invention〕

The effects obtained by the present invention are as follows.

(1) The developer is capable of faithfully developing and transferring latent images, maintains its initial characteristics even when used continuously over a long period of time, and does not cause toner aggregation or change in charging characteristics.

(2) A developer that can reproduce stable images that are unaffected by changes in temperature and humidity, and that can also produce images in vivid chromatic colors.

(3) It is a developer that does not stain, rub or scratch the electrostatic latent image surface, has an easy cleaning process, has excellent fixing properties, and is particularly free from problems such as high-temperature offset.

Claims (1)

[Claims] 1. At least a binder resin, a colorant, and the following general formula [I
] A toner for developing electrostatic images characterized by containing a compound represented by the following. ▲There are mathematical formulas, chemical formulas, tables, etc.▼〔I〕 (However, A is the residue of a compound having a phenol group, R^1
represents a methylene group or an ethylene group, R^2 and R^3 represent an alkyl group having 1 to 8 carbon atoms, an aryl group, an alkenyl group, an aralkyl group, or a cyclic (including heterocyclic) alkyl group, and R^2 and R ^3 may be combined to form a ring. n_
1 represents 0 or 1, and n_2 represents a number from 1 to 400. ) 2. The electrostatic charge according to claim 1, wherein the content of the compound represented by the general formula [I] is 0.01 to 10 parts by weight based on 100 parts by weight of the binder resin. Toner for image development. 3. The softening point of the compound represented by the general formula [I] is 50℃
The toner for developing an electrostatic image according to claim 1, which has the above properties.