JPS6199153A - Toner for developing electrostatic images - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel toner containing guanidine or a salt of a guanidine derivative for developing electrostatic images in electrophotography, electrostatic recording, electrostatic printing, and the like.

Since then, as an electrophotographic method, U.S. Patent No. 2,297.69
Various methods are described in Japanese Patent Publication No. 1, Japanese Patent Publication No. 42-23910, Japanese Patent Publication No. 43-24748, etc. They impart a uniform electrostatic charge onto a photoconductive insulator layer and form an electrostatic latent image by irradiating the insulator layer with a light image, which is then referred to in the art as a toner. After developing and visualizing the image using fine powder and transferring the powder image to paper or the like as necessary, it is fixed by heating, pressure, or solvent vapor.

Development methods applicable 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 single-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.

Furthermore, the one-component development methods include the powder cloud method, in which toner particles are sprayed, and the contact development method (contact development or toner development method, in which toner particles are brought into direct contact with the electrostatic latent image surface for development). (also referred to as development), japing development method in which toner particles are not brought into direct contact with the electrostatic latent image surface, but are charged and flown toward the latent image surface by the electric field of the electrostatic latent, magnetic conductivity There is a Pugne Dry method in which toner is brought into contact with a latent image surface for development. Toners used in these development methods include fine powders in which dyes or pigments are dispersed in natural or synthetic resins, such as those in which colorants are dispersed in binder resins such as polystyrene. Finely pulverized particles of about 1 to 30 g are used as magnetic or non-magnetic toner. As the magnetic toner, one containing magnetic particles such as magnetite is used. Furthermore, 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.

Further, the toner has a positive or negative charge depending on the polarity of the electrostatic latent image to be developed. There is a method of charging the toner using only the triboelectricity of the resin, which is the main component of the toner, in order to make the toner retain an electric charge, but since the toner has a low chargeability with this method, the image obtained by development is prone to fogging. It becomes unclear.

Therefore, in order to impart desired triboelectric chargeability to the toner, dyes, pigments, and charge control agents that impart chargeability are added to the toner.

Hitherto, as control agents for controlling toner to be positively charged, nigrosine-based oil-soluble dyes, azine dyes having an alkyl group, basic dyes, lakes of basic dyes, and the like have been proposed.

These charge control agents are usually added to thermoplastic resins,
The toner is heat-melted and dispersed, pulverized, and adjusted to an appropriate particle size as required.

However, these dyes used as charge control agents have complex structures, inconsistent properties, and poor stability. In addition, it is easily decomposed or deteriorated due to decomposition during thermal kneading, mechanical impact, friction, changes in temperature and humidity conditions, etc., 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 developed using a copying machine, the charge control agent may decompose or change in quality as the number of copies increases, causing deterioration of the chargeability of the toner during durability. be. Furthermore, since it is extremely difficult to uniformly disperse these charge control agents in the plastic resin, there is a fatal problem of causing a difference in the amount of frictional charge between the toner particles obtained by pulverization. are doing. For this reason, various methods have been used to achieve more uniform dispersion.

For example, basic nigrosine dyes are used in combination with higher fatty acids 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 toner fluidity, fogging, and a decrease in image density. Alternatively, in order to improve the dispersibility of these charge control agents in 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. However, the inherent poor dispersion cannot essentially be avoided, and the current situation is that sufficient charge uniformity has not yet been obtained for practical use.

The substances generally known as charge control agents are:
The problem is that most of them are dark in color and cannot be incorporated into bright chromatic developers.

In this way, when conventional charge control agents are used in toner,
between toner particles or between toner and carrier,
It occurs on the surface of toner particles between the toner and a toner carrier such as a sleeve. This causes variations in the amount of charge, which tends to cause problems such as development fog, toner scattering, and carrier contamination, and these problems become more noticeable when a large number of copies are made, and in effect the copying machine This results in an unsuitable result.

Under high-temperature conditions, the toner image transfer efficiency decreases significantly, and many of them become unusable.

Furthermore, when a conventional toner containing the charge control agent is used for a long period of time, the toner adheres to the photoreceptor surface due to poor charging, which may adversely affect latent image formation (filming). (Phenomenon), there are many that have a negative effect on the cleaning process of a copying machine by causing scratches on the surface of the photoreceptor or cleaning members such as cleaning blades, or accelerating wear of the members.

As described above, conventional charge control agents have many problems.
There is a strong demand in the technical field to solve these problems. 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.

An object of the present invention is to provide a new technique in the field of toner charge control that eliminates such 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 one-component development, and to improve the distribution of triboelectricity. The object of the present invention is 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 of the present invention is to use a developer to carry out development and transfer faithful to the latent image, i.e., toner adhesion in the background area during development, to prevent fogging and toner scattering around the edges of the latent image. The object of the present invention is to provide a developer which can obtain high image density without any problems and has good halftone reproducibility. 1 Furthermore, another object of the present invention is to maintain the initial characteristics even when the developer is used continuously over a long period of time;
The object of the present invention is to provide a developer that does not cause toner aggregation or change in charging characteristics.

Furthermore, another object of the present invention is to develop a developer that reproduces stable images unaffected by changes in temperature and humidity, and in particular, a developer that has high transfer efficiency and does not cause scattering or transfer omission during transfer at high or low humidity. The objective is to provide a developer.

Still another object of the present invention is to provide a developer with bright chromatic colors.

Another object of the present invention is to provide a developer with excellent storage stability that can maintain its initial characteristics even after long-term storage.

Still another object of the present invention 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 of the present invention is to provide a developer having good fixing properties, especially a developer that does not cause problems such as high temperature offset.

More specifically, the object of the present invention is (wherein R1, R2, R3, R4, R5 and R6 are the same or different groups, and each represents a hydrogen atom, an alkyl group,
Represents a group derived by removing hydrogen from a cyclic alkyl group, alkenyl group, aryl group, alkylene group, aralkyl group, arylene group, or a heterocycle containing a nitrogen atom, sulfur atom, or oxygen atom, and X- is an inorganic anion or An object of the present invention is to provide a toner for developing an electrostatic image, which is characterized by containing a salt of guanidine or a guanidine derivative represented by the following organic anion. In addition, as X-, for example, a halogen atom, 1/2S042-, 1/2SO32
-, NO3-, 1/3PO43-, ClO4-, 1/2
Examples include inorganic anions such as Cr2O72-, BF4-, PF6-, anions of organic acids such as acetic acid and oxalic acid, and anions of organic compounds having sulfonyl groups, sulfino groups, phosphonic groups, and the like.

The present inventors have discovered that guanidine and salts of guanidine derivatives represented by the above formula are thermally and temporally stable and, when included in a developer, are high-quality charge control agents that provide a developer with excellent electrophotographic properties. I found that.

Examples of the guanidine salts and guanidine derivative salts according to the present invention include the following.

Compound example (1) Compound example (2) Compound example (
3) Compound example (4) Compound example (5)
Compound Example (6) Compound Example (7) The guanidine salt or guanidine derivative salt added to the toner of the present invention is not limited to the above-mentioned salts.

A salt of guanidine or a salt of a guanidine derivative can be produced, for example, by the following synthetic method. Furthermore, conventionally known methods can also be applied.

Methods for incorporating the above-mentioned salts 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 salts to be used is determined by the type of resin, the presence or absence of additives used as necessary, and the toner manufacturing method, including the dispersion method, and is uniquely limited. However, it is preferably 0.1 to 10 parts by weight (more preferably 0.5 to 5 parts by weight) per 100 parts by weight of the binder resin.
(parts by weight).

In addition, when externally added, 0.0 parts by weight per 100 parts by weight of resin.
1-10 parts by weight, preferably 0.1-5 parts by weight.

Further, it is also possible to add a conventionally known charge control agent to the toner of the present invention as long as it does not interfere with the function of the toner of the present invention.

Colorants used in the toner of the present invention include carbon blank, lamp black, iron black, ultramarine blue, nigrosine dye, aniline blue, phthalocyanine blue, cap cyanine green, Hansa Yellow G, rhodashin 6G lake, calco oil blue, and chrome. Examples include yellow, quinacridone benzidine yellow, rose bengal, triallylmethane dyes, monoazo dyes and disazo dyes and pigments, and conventionally known dyes and pigments may 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 copolymers, styrene-propylene copolymers,
Styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer Copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-methyl chloromethacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl Methyl ether copolymer, styrene-vinylethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-malein Acid copolymers, styrenic copolymers such as styrene-maleate copolymers, polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester polyurethane, polyamide, epoxy resin, polyvinyl Examples include butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenolic resin, aliphatic or aliphatic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax, etc., either alone or in combination. Can be used.

Particularly suitable binder resins for pressure fixing include the following, which can be used alone or in combination.

Polyolefin (low molecular weight polyethylene, low molecular weight polypropylene, polyethylene oxide, polytetrafluoroethylene, etc.); Epoxy resin; Polyester resin: Styrene-butadiene copolymer (monomer ratio is 5:95 to 30:70)
); Olefin copolymers (ethylene-acrylic acid copolymer, ethylene-acrylic ester copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic ester copolymer, ethylene-vinyl chloride copolymer)
ethylene-vinyl acetate copolymer, ionomer resin);
Polyvinylpyrrolidone; methyl vinyl ether-maleic anhydride copolymer; maleic acid-modified phenonyl resin; and phenol-modified terpene resin.

Furthermore, the toner of the present invention can be mixed with carrier powder and used as a two-component developer.

Examples of carriers that can be used in the present invention include:

Any known material can be used. Examples include magnetic powders such as iron powder, ferrite powder, and nickel powder, as well as glass beads and their surfaces treated with resin or the like.

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

These ferromagnetic materials preferably have an average particle size of about 0.1 to 2 μm, and the amount contained in the toner is 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. 40 to 150 parts by weight.

Further, the uninvented toner may be mixed with additives as necessary. Additives include, for example, lubricants such as Teflon and zinc stearate; flow agents or anti-caking agents such as colloidal silica, titanium oxide, and aluminum oxide; conductivity agents such as carbon black and tin oxide; or low molecular weight agents. There are fixing aids such as polyethylene.

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

Alternatively, other components are dispersed in a binder resin solution and then spray-dried, or the monomers that should constitute the binder resin are mixed with the specified materials to form an emulsified suspension and then polymerized. A method such as a polymerization toner production method in which a toner is obtained by subjecting the toner to the toner can be applied.

The toner produced by these methods can be used for developing to visualize electrostatic images in electrophotography, electrostatic recording, electrostatic printing, etc. by conventionally known means, and has the following advantages. It has the following effects.

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 light-sensitive materials and copying machines are eliminated, and the toner of the present invention containing a compound having a charge-controlling polar group has extremely excellent physical properties. Therefore, the toner can be stored for a long period of time without the problems of toner aggregation, clumping, and low-temperature flow during storage, which were major problems in the past. It's also excellent.

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. Further, since there is little color tone disturbance caused by the charge control agent, color images with excellent colors can be formed by using it as a color electronic Sanada toner.

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

[Example 1] Prescribed styrene/butyl acrylate (80/20) copolymer (weight average molecular weight Mw: approximately 300,000)
--------100 parts carbon black (Mitsubishi #44)
------- 10 parts Low molecular weight polyethylene wax ------- 2 parts Compound example (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 coarsely pulverized with a cutter mill, then pulverized with a pulverizer using a jet stream, and further classified using an air classifier to obtain particles with a particle size of 5 to 2.
A fine powder of 0μ was obtained.

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

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 1.3
2, 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.

Further, during the durability test, the above-mentioned filming phenomenon on the photoreceptor involving toner was not observed at all, and no problems were found in the cleaning process.

Also, there is no trouble in the fixing process at this time.

At the end of the durability test, the fuser was observed, and there were no scratches or damage to the rollers, and there was almost no staining from offset toner, so there was no problem at all in practical use.

Furthermore, when the environmental conditions were set to 35°C and 85%, the image source density was 1.25, a value that was almost unchanged from normal temperature and humidity, and clear images were obtained without fogging or scattering. Next, when a transferred image was obtained at a low temperature and low humidity of 10° C. and 10%, the image density was as high as 1.35, solid black was developed and transferred extremely smoothly, and the image was excellent with no scattering or hollow spots.

[Comparative Example 1] A developer was obtained in the same manner as in Example 1, except that 2 parts of nigrosine dye was used instead of 2 parts of Compound Example (1), and development, transfer, and fixing were performed. 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. Furthermore, during durability, the fixed image tended to get caught up in the fixing roller during the fixing process, and there was difficulty in peeling it off from the roller.

When an image was obtained under conditions of 35° C. and 85%, the image source was as low as 0.88, and fogging, scattering, and roughness increased. The transfer efficiency was also as low as 69%.

When an image was obtained under conditions of 10° C. and 10%, the image density was as low as 0.91, and there was severe scattering, fogging, roughness, and noticeable transfer defects.

[Example 2] Instead of using 2 parts of Compound Example (1), Compound Example (2) was used.
A developer was obtained in the same manner as in Example 1, except that 3 parts of the developer were used, and development, transfer, and fixing were performed.

The results are shown in Tables 1 and 2.

[Example 3] Compound example (3) instead of using 2 parts of compound example (1)
A developer was obtained in the same manner as in Example 1, except that two parts of the developer were used, and development, transfer, and fixing were performed.

The results are shown in Tables 1 and 2. show.

[Example 4] Compound Example (1) Instead of using 2 parts, Compound Example (5
) A developer was obtained in the same manner as in Example 1 except that 3 parts of
Development, transfer, and fixing were performed.

The results are shown in the fJSt table and Table 2.

[Example 5] Instead of using 2 parts of Compound Example (1), Compound Example (6) was used.
A developer was obtained in the same manner as in Example 1, except that two parts of the developer were used, and development, transfer, and fixing were performed.

The results are shown in Tables 1 and 2.

[Example 6] Instead of using 2 parts of Compound Example (1), Compound Example (7) was used.
A developer was obtained in the same manner as in Example 1, except that two parts of the developer were used, and development, transfer, and fixing were performed.

The results are shown in Tables 1 and 2. show.

[Example 7] Styrene/butyl acrylate (80/20) copolymer (weight average molecular weight Mw: approx. 300,000) --------1--100 parts 43 Iron oxide EPT-50
0 (manufactured by Toda Kogyo)---------------
-----60 parts low molecular weight polypropylene wax---
------- Two-part compound example (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 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 20μ. Ta.

Next, hydrophobic colloidal silica R was added to 100 parts of the fine powder.
-972 (manufactured by Nippon Aerosil Co., Ltd.) was mixed in a sample mill to prepare a one-component magnetic toner. The amount of triboelectric charge of this toner was measured by a conventional blow-off method. This toner was applied to a commercially available copying machine (trade name: NP-15QZ, manufactured by Canon Inc.) to produce an image. The results are shown in Tables 1 and 2.

[Example 8] Instead of using 2 parts of Compound Example (1), Compound Example (2) was used.
A developer was obtained in the same manner as in Example 7, except that 3 parts of the developer was used, and development, transfer, and fixing were performed.

The results are shown in Tables 1 and 2.

[Example 9] Instead of using 2 parts of Compound Example (1), Compound Example (3) was used.
A developer was obtained in the same manner as in Example 7, except that two parts of the developer were used, and development, transfer, and fixing were performed.

The results are shown in Tables 1 and 2.

[Example 10] Instead of using 2 parts of Compound Example (1), Compound Example (5) was used.
A developer was obtained in the same manner as in Example 7, except that two parts of the developer were used, and development, transfer, and fixing were performed.

The results are shown in Tables 1 and 2.

[Example 11] Instead of using 2 parts of Compound Example (1), Compound Example (6) was used.
A developer was obtained in the same manner as in Example 7, except that two parts of the developer were used, and development, transfer, and fixing were performed.

The results are shown in Tables 1 and 2.

(Example 12) Instead of using 2 parts of Compound Example (1), Compound Example (7)
A developer was obtained in the same manner as in Example 7, except that two parts of the developer were used, and development, transfer, and fixing were performed.

The results are shown in Tables 1 and 2.

[Comparative Example 2] A developer was obtained in the same manner as in Example 7, except that 2 parts of benzylmethyl-hexadecyl ammonium chloride was used instead of 2 parts of Compound Example (1), and an image was obtained in the same manner. At room temperature and humidity, there was little fog, but the image density was low at 0.81, line drawings were scattered, and solid black was noticeably rough. Also, the above-mentioned filming phenomenon during durability and problems in the fixing process were also observed in Comparative Example 1.
It was almost the same unpleasant thing.

When an image was obtained under conditions of 35° C. and 85%, the image density was as low as 0.72, and fogging, scattering, and roughness increased, making it unusable. Transfer efficiency is also 63
% was low. When images were obtained under conditions of 10° C. and 10%, the density of each image was as low as 0.73, and there were severe scattering, fogging, roughness, and noticeable transfer defects.

[Example 13] Styrene/butyl acrylate (80/20) copolymer (weight average molecular weight Mw: approximately 300,000)---------
----------100 parts Copper phthalocyanine blue pigment---5 parts Low molecular weight polypropylene wax---2m Compound example (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 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 20μ. Ta.

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

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

When this developer was used to produce an image using the developing device shown in the attached figure, a good image with a bright blue color was obtained.

To explain the developing device, in the attached drawing, 1 is an electrostatic image holder, 2 is a toner carrier, 3 is a hopper, and 52
Reference numeral 1 indicates a magnetic brush made of a magnetic particle toner mixture, 58 indicates a toner-4 regulating plate, 50 indicates a fixed magnet, 6 indicates a developing bias, and 5 indicates 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 toner layer thickness, and the toner 5 on the toner carrier 2 is caused to fly onto the electrostatic image on the electrostatic image carrier 1 for development.

The thickness of the toner layer is controlled by the size of the magnetic brush 52, ie, the amount of magnetic particles, and the regulating blade 58. 1 and 2
A developing bias of 6 may be applied with a gap larger than the toner layer thickness.

[Example 14] Compound example (5) instead of using 2 parts of compound example (1)
A developer was obtained in the same manner as in Example 13, except that 2 parts of
Development, transfer, and fixing were performed, and the evaluation results of each Example and Comparative Example are shown in Tables 1 and 2.

[Example 15] Instead of using 2 parts of Compound Example (1), Compound Example (4) was used.
The procedure was carried out in the same manner as in Example 1 except that 2 parts of
．． 19, and a good image was obtained. In addition, room temperature and normal humidity, high temperature and high humidity (35℃, 85%), or low temperature and low humidity (1
Good results were also obtained in a 30,000-sheet durability test under conditions of 0° C. and 10%).

Table 1 (Note) O...Good, △...Slightly good, ×...Poor 2nd
table

[Brief explanation of drawings]

The accompanying drawings are diagrams for explaining an apparatus for carrying out an example of a developing method 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, 58----regulating plate .

Claims (1)

[Claims] Formula ▲ Numerical formula, chemical formula, table, etc.
X^ 1. A toner for developing an electrostatic image, comprising a salt of guanidine or a guanidine derivative represented by an inorganic anion or an organic anion.