JPS61160759A - Toner for developing electrostatic charge image - Google Patents

Abstract

PURPOSE:To make the development and transfer faithful to a latent image possible by incorporating a specific compd. into a binder resin. CONSTITUTION:This toner contains the compd. expressed by formula 1 in the binder resin. Ar in formula 1 denotes an unsubstd. or substd. aryl. The compd. is stable with heat and time, has lower hygroscopicity and is a good-quality electric charge controlling agent to yield a developer having excellent electrophotographic characteristics when incorporated into the developer. The representative embodiment of the compd. expressed by formula 1 is the formula 2. The compd. is used in a 0.0-10pts.wt. (more preferably 0.5-5pts.wt.) range by 100pts.wt. the binder resin in the case of inside addition. The compd. is used preferably at 0.01-10pts.wt. by 100pts.wt. the resin in the case of external addition.

Description

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

[Prior Art] Conventionally, as an electrophotographic method, U.S. Patent No. 2,297,88
No. 1, Special Publication No. 1972-23910 and Special Publication No. 1973-
Various methods are described in Japanese Patent No. 24748, etc., but in short, these methods apply a uniform electrostatic charge on a photoconductive insulating layer and irradiate the insulating layer with a light image to increase the electrostatic potential. An image is formed, and then the latent image is developed and visualized using fine powder called toner in this technology, and if necessary, the powder image is transferred to paper or the like, and then fixed by heat, pressure, or solvent vapor. It is something to do.

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 developing methods include:
Magnetic brush method using iron powder carrier, beads and
There are a cascade method using a carrier, a fur brush method using fur, etc.

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

As toners applied to these 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 particles are used as toner. As the magnetic toner, one containing magnetic particles such as magnetite is used. In the case of a system using a so-called two-component developer, the toner is usually mixed with carrier particles such as glass beads and iron powder.

Further, the toner is made to have a positive or negative charge depending on the polarity of the electrostatic latent image to be developed.

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

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

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

Nigrosine, azine dyes containing an alkyl group having 2 to 18 carbon atoms (Japanese Patent Publication No. 1827/1983), basic dyes (e.g. C,1,Ba5ic Yellow 2 (C,1
, 41000).

C,1,Ba5ic Yellow 3,
C, 1, Ba5ic Red 1 (C:, 1.4
51130), C,1,Ba5ic Red
9 (C, I.

42500), C, 1, Ba5ic Violet
1 (C,1,42535),C,1,Ba5ic
Violet 3 (G, 1. 42555)
C,1,Ba5icViolet 10 (C,1
, 45170), G, 1. Ba5ic Viol
et 14 (fll:, r, 4251G), C
,I. Ba5ic Blue l (C0■..

42025), C,l Ba5ic Blue 3
(C0L 51005), C,I.

Bs1c Blue 5 (C, 1, 42140), C
,1,Ba5ic Blue7 (C,1,4259
5), G, 1. Ba5ic Blue 9 (C
, L52015), C,1,Ba5ic Blue
24 (C, 1, 52030), C, I.

Ba5ic Blue 25 (C, 1, 52025)
,G,1. Ba5ic Blue2B (G, 1.
44045), C,1,Ba5ic Gre
en 1 (C, I.

42040), C,i Ba5ic Green 4
(C:, 1.42000).

G, 1.42510, C, 1,45170 nato, kore l"+nobasic staining.

(Laking agents include phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide, etc.), C, 1,5o
lvent Black 3 (C, 1, 2Ei150
), handy x o -G (C, 1, 11880)
,G,1. MordlantBlack 11, C,
1, Pigment 2 Black 1, Gilenite, Asphalt, etc.

and quaternary ammonium salts, such as benzylmethyl-
Contains amine groups, such as organic tin compounds such as hexadecyl ammonium chloride, acyl-trimethylammonium chloride, and dibutyltin oxide, metal salts of higher fatty acids, inorganic fine powders such as glass, mica, and zinc oxide, and metal complexes such as EDTA and acetylacetone. Polyamine resins such as vinyl polymers that contain amine groups and condensation polymers that contain amine groups.

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

Metal complex salts of heptanoazo dyes described in Japanese Patent Publication Nos. 41-20153, 43-27598, 44-8397, 45-28478, etc.

Dyes and pigments such as nitrofumic acid and its salts or C, 1,14645 described in JP-A-50-133338.

and Special Publication No. 55-42752, Special Publication No. 58-415
No. 08.

Metal complexes such as C01Cr and Fe of salicylic acid, naphthoic acid, and guicarboxylic acid, sulfonated copper phthalocyanine pigments, nitro groups, and styrene oligomers into which halogens are introduced, as described in Japanese Patent Publication No. 59-7384 and Japanese Patent Publication No. 59-7385, etc. , chlorinated paraffin, melamine resin, etc.

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

There are some new proposals recently that are different from these, but none have surpassed the dye-pigment-based ones in terms of comprehensiveness, and there are still examples of dyes using dyes, although this is still unsatisfactory. Most of them are.

These are usually added to thermoplastic resins, thermally melted and dispersed, and then finely pulverized and adjusted to a suitable particle size as necessary before use.

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

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

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

Moreover, most of the substances generally known as charge control agents have a dark color, and there is a problem in that they cannot be incorporated into bright chromatic color developers.

In addition, many charge control agents are hydrophilic, and due to poor dispersion in these resins, when pulverized after melt-kneading,
The dye is exposed on the toner surface.

Therefore, when using toner under high temperature conditions, these
Since the charge control agent is hydrophilic, it has the disadvantage that good quality images cannot be obtained.

In this way, when conventional charge control agents are used in toner,
Variations occur in the amount of charge generated on the surface of toner particles between toner particles, between toner and carrier, or between toner and a toner carrier such as a sleeve,
Problems such as development fog, toner scattering, and carrier contamination are likely to occur, and these problems become more noticeable when a large number of copies are made, resulting in a result that is practically unsuitable for copying machines.

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

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

Furthermore, when conventional charge control agents are used in toner, there are many that have a large effect on the thermal melting properties of the toner and degrade fixing performance.In particular, they deteriorate high-temperature offset performance, and the transfer material during heat roll fixing. There are some that increase the stickiness of the rollers and reduce the durability life of the rollers.

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

[Problems to be Solved by the Invention] 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 amount of triboelectric charge between toner particles, between a toner and a carrier, or between a toner and a toner carrier such as a sleeve in the case of -component development, and to maintain a stable triboelectricity distribution. To provide a developer that is sharp and uniform, and whose charge amount can be controlled to suit the developing system used.

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

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

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

Still 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 during long-term storage.

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

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

[Means and effects for solving the problems] The present invention is characterized in that the binder resin contains a compound represented by the following general formula [11 (wherein Ar represents unsubstituted or substituted aryl)] Toner for developing electrostatic images.

The above 7-aryl group is a phenyl group or a naphthyl group.

Further, the substituent of the above aryl group is an alkyl group, halogen or nitro group.

The present inventors have discovered that the compound represented by the general formula [I] is thermally and temporally stable, has low hygroscopicity, and when contained in a developer, provides a high-quality developer with excellent electrophotographic properties. It was discovered that it is a charge control agent.

Typical specific examples of the compound represented by the general formula [I] include the following.

[Compound example] These compounds are synthesized by known methods.

That is, it is synthesized by the reaction between an aromatic Grignard reagent and bismuth rogenide.

[Reaction Example] Methods for incorporating the above compound into the developer include a method of adding it inside the developer and a method of adding it externally. When internally added, the amount of these compounds used is determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner manufacturing method, including the dispersion method, and is not uniquely limited. However, it is preferably 0.1 to 10 parts by weight (more preferably 0.5 to 10 parts by weight) per 100 parts by weight of the binder resin.
5 parts by weight).

In addition, when externally added, 0.
01 to 10 parts by weight is desirable.

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

Colorants used in the present invention include carbon black, lamp black, iron black, ultramarine blue, nigrosine dye, aniline blue, phthalocyanine blue, phthalocyanine clean, Hansa Yellow G, rhodamine 6G, lake,
Calco oil blue, chrome yellow, quinacridone,
Any conventionally known dyes and pigments such as benzidine yellow, rose bengal, triallylmethane dyes, hepanoazo 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 polyp-chlorostyrene and polyvinyltoluene: styrene-p-chlorostyrene 19 combination, 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 Coalescence, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-methyl chloromethacrylate copolymer, styrene-acrylonitrile copolymer, styrene- Vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene- Styrenic copolymers such as maleic acid copolymers and styrene-maleic ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyurethane, polyamide, epoxy resins , polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax, etc., singly or in combination. It can be used as

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

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

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

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. Things can be given.

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, iron, cobalt, and nickel. metals such as aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese,
Examples include alloys of metals such as selenium, titanium, tungsten, and vanadium, and mixtures thereof. These ferromagnetic materials preferably have an average particle size of about 0.1 to 2 tiles, and are contained in the toner in an amount of about 20 to 2001 parts by weight per 100 parts by weight of the resin component, particularly preferably about 100 parts by weight of the resin component. The amount is 40 to 150 parts by weight.

The toner of the present invention may also contain additives as required. Examples of additives include lubricants such as Teflon and zinc stearate, abrasives such as cerium oxide and silicon carbide, or colloidal silica, etc. Fluidity imparting agents such as aluminum oxide, anti-caking agents, or conductivity imparting agents such as carbon black and tin oxide,
Alternatively, a fixing aid such as low molecular weight polyethylene may be used as a vinyl or non-vinyl thermoplastic resin and a coloring agent to prepare the toner for developing an electrostatic image according to the present invention. Pigments or dyes, magnetic materials, additives, etc., if necessary, are thoroughly mixed using a ball mill or other mixer, and then melted, kneaded, and kneaded using a heat kneader such as a heated roll, niegu, or extruder. Pigments or dyes are dispersed or dissolved in the resins, which are cooled and solidified, and then crushed and classified to obtain particles with an average particle size of 5 to 5.
You can get 20 liters of toner.

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

The toners prepared by these methods can be used for developing to visualize electrostatic 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 frictional charge between toner particles is uniform, 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 development fog, toner scattering, and contamination of electrophotographic photosensitive materials and copying machines can be eliminated, and since the toner of the present invention is extremely superior, 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 the operations of charging, exposure, development, and transfer are successively repeated. Furthermore, there is no color tone disturbance caused by the charge control agent, and when used as a color electrophotographic toner, it is possible to form color images with excellent colors. However, this does not limit the present invention in any way, and all parts in the following formulations are by weight.

Example 1 Carbon black (Mitsubishi % 44) 10 parts Low molecular weight polyethylene wax 2 parts Compound (1)
Two parts of the above materials were thoroughly mixed in a blender and then kneaded with two rolls heated to 150°C. After the kneaded material 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 20. Obtained.

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

Further, the amount of triboelectric charge of the developer was measured by a conventional blow-off method.

Next, by a conventionally known electrophotographic method,
A negative electrostatic image was formed, and this was powder-developed using the above-mentioned developer using a magnetic brush method to create a toner image, which was transferred to plain paper and heat-fixed. The resulting transferred image has a density of 1.
27, which was sufficiently high, and there was no fogging at all, and a good image with high resolution was obtained without toner scattering around the image. Transfer images were continuously created using the above developer and their durability was examined, and the transferred images after 30,000 copies were also completely dull compared to the initial images. −
Further, during durability, the above-mentioned filming phenomenon related to toner on the photoreceptor was not observed at all, and no problems were found in the cleaning process. Also, there were no troubles in the fixing process at this time, and at the end of the 30,000-sheet durability test, the fixing machine was observed and there were no scratches or damage to the rollers, and there was almost no dirt from offset toner, so there were no practical problems at all. Ta.

In addition, when the environmental conditions were set to 35°C and 85%, the density of one image was 1.19, a value that was almost unchanged from normal temperature and humidity, and clear images were obtained without fogging or scattering, and the durability was 30,000 yen. There was almost no change until the end. Next 15
When a transferred image was obtained at a low temperature and low humidity of 10% at 100° C., the image density was as high as 1.30, and even a flat black image was developed and transferred extremely smoothly, resulting in an excellent image with no splatters or voids. Durability was carried out under these environmental conditions, and even though copies were made continuously and intermittently, the density variation was ±0.2 up to 30,000 copies, 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.

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

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.

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

When an image was obtained at 35° C. and 85%, the image density was as low as 0.88, and fogging, scattering, and roughness increased. The transfer efficiency was also as low as 89%.

When an image was obtained under conditions of 15° C. and 10%, the image density was as low as 0.91, and there was severe scattering, fogging, and roughness, and transfer omissions were noticeable. I tried to take continuous images, but 3
After about 0,000 sheets, the density became 0.53, making it impractical.

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

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

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

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

Example 4 A developer was obtained in the same manner as in Example 1 except that 2 parts of compound (4) was used instead of 2 parts of compound (1), and development, transfer, and
Fixation was performed and an image was obtained in the same manner.

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

Example 5 Triiron tetroxide EPT-500 (manufactured by Toda Kogyo) 60 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. After the kneaded material is left to cool naturally, it is roughly pulverized using a cutter mill, then pulverized using a pulverizer using a jet stream, and further classified using an air classifier to obtain a fine powder with a particle size of 5 to 20 l. Obtained.

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

Further, the amount of triboelectric charge of this toner was measured by a conventional blow-off method.

When this toner was applied to a reprint copy a (trade name NP-1502, manufactured by Canon ■) and an image was produced, good results almost the same as in Example 1 were obtained.

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

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

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

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

Comparative Example 2 A developer was obtained in the same manner as in Example 5, except that 2 parts of benzylmethyl-hexadecyl ammonium chloride was used instead of 2 parts of Compound (1) in Example 5, and an image was obtained in the same manner. At room temperature and humidity, there is little fog, but the image density is 0.8
1 and the line drawings were scattered, and the solid black was noticeably rough. I checked the durability, and the density was 0.4 after 30,000 sheets.
It dropped to 8.

In addition, the above-mentioned filming phenomenon during durability and problems in the fixing process were almost the same as those in Comparative Example 1, and were rare. Also, when images were obtained under conditions of 35° C. and 85%, the image density was 0.72. This resulted in an increase in fogging, scattering, and roughness, making it unusable.

The transfer efficiency was also as low as 63%. When an image was obtained under the conditions of 15° C. and 10%, the image density was as low as 0.73, and there was severe scattering, fogging, roughness, and transfer omissions were noticeable.

Continuous image formation was performed, but the density became 0.58 after 30,000 sheets, making it impractical.

Example 8 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. After the kneaded material was left to cool naturally, it was roughly pulverized with a cutter mill, then pulverized using a pulverizer using a jet stream, and further classified using an air classifier to obtain a fine powder with a particle size of 5 to 20B. Ta.

Further, the amount of triboelectric charge of the fine powder was measured by a conventional blow-off method.

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

When one image was produced using this developer using the developing method shown in Figure 1, a good image with a bright blue color was obtained, and after producing 1,500 images, the toner/carrier was reduced to Log 750g. However, there was almost no change in the image density, and after that, while replenishing toner,
Good images were obtained even after printing up to 10,000 images.

To explain this developing method, in FIG. 1, l is an electrostatic image holder, 2 is a toner carrier, 3 is a hopper, and 52
3 indicates a carrier toner mixture; 3 indicates a magnetic brush; 58 indicates a blade for regulating toner thickness; 50 indicates a fixed magnet; 6 indicates a developing bias; 5 indicates a toner.

That is, the magnetic brush 52 formed on the toner carrier 2 is circulated by rotating the toner carrier 2, takes in the toner in the hopper 3, and uniformly coats the toner 2 in a thin layer. Next, the toner carrier 2 and the electrostatic image carrier 1 are opposed to each other with a gap larger than the thickness of one toner layer, and the toner 5 on the toner 2 is developed by flying onto the electrostatic charge image on the 1.

The thickness of the toner layer is controlled by the size of the magnetic brush 52, i.e. the amount of carrier, and the regulating blade 58. l and 2
A developing bias of 6 may be applied by making the gap between the toner and the toner layer larger than the thickness of the toner layer.

The evaluation results of each example and comparative example are shown in Tables 1 and 2.

Table 1 O Good, Δ Slightly Poor, X Bad Clothes 2 0 Good, OΔ Slightly Good, Δ Slightly Poor, X
Defective [Effects of the Invention] The following effects can be obtained by the present invention.

(1) The amount of triboelectric charge between toner particles or between toner and carrier, between toner and toner carrier in the case of -component development is stable, and the distribution of triboelectricity is sharp and uniform, and the developer used This is a developer that can control the amount of charge to suit the system.

(2) The developer is capable of faithfully developing and transferring a latent image, maintains its initial characteristics even when used continuously over a long period of time, and has no change in toner aggregation or charging characteristics.

(3) The developer is capable of reproducing stable images unaffected by changes in temperature and humidity, and has particularly high transfer efficiency even under high temperature and high humidity conditions and low temperature and low humidity conditions.

(4) The developer is easy to clean and does not stain, abrade, or scratch the electrostatic latent image surface, and has good fixing properties.

[Brief explanation of drawings]

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

Claims (3)

[Claims] (1) Electrostatic charge characterized by containing a compound represented by the following general formula in the binder resin ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, Ar represents a substituted or unsubstituted aryl group.) Toner for image development. (2) The toner for developing electrostatic images according to claim 1, wherein the aryl group is a phenyl group or a naphthyl group. (3) The toner for developing electrostatic images according to claim 1, wherein the substituent of the substituted aryl group is an alkyl group, halogen, or nitro group.