JPS61137162A - Electrostatic charge image developing toner - Google Patents

Abstract

PURPOSE:To obtain a toner stable, sharp, and uniform in triboelectrified amt., and controllable to a suitable amt. for the developing system to be used, and having long life and superior fixability characteristics, etc. by incorporating a specified bistetraazolium compd. as a charge controller. CONSTITUTION:The toner contains together with a binder as the charge controller in the inside or in a state attached to the outside, a compd. represented by the formula in which each of R1-R4 is H, or one of substituents having base skeletons of hydrocarbons, such as alkyl, cycloalkyl, alkenyl, aryl, aralkyl, alkylene, and arylene groups, etc., or a group having a hetero ring contg. N, S, or O, or a combination of them; Y is a divalent group having a substituent like R1, etc.; and X is Cl, Br, I, SO4, SO3, NO3, or an org. acid residue of C2O4<2->. This charge controller can keep the toner color clear, prevent agglomeration and offset, and form a superior color image.

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, various electrophotographic methods have been described in US Pat. No. 2,297,891, Japanese Patent Publication No. 42-23910, Japanese Patent Publication No. 43-24748, etc. In short, they impart a uniform electrostatic charge to a photoconductive insulating layer, form an electrostatic latent image by irradiating the insulating layer with a light image, and then transfer the latent image to a toner using the technique. The image is developed and visualized using a fine powder known as a powder, and if necessary, the powder image is transferred to paper or the like, and then fixed by heating, pressure, solvent vapor, or the like.

Development methods applicable to these electrophotographic methods include:
Broadly speaking, there are dry development methods and wet development methods. The former 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 the electrostatic latent image; and magnetic conductive method. There is the MagneDry method, which develops by bringing a 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 pL 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 hold 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 currently known in the art include the following.

(1) Things that control the toner to be positively charged Nigrosine, azine dyes containing an alkyl group having 2 to 1B carbon atoms (Japanese Patent Publication No. 1827-1827), basic dyes (e.g. C, 1, B
a5ic Yellow 2 (C, 1,41000)
, CA, Ba5ic Yellow 3, C,1
, Ba5ic Red 1 (C, 1, 45180)
,C,1,Ba5ic Red 9 (C:,1゜42
500), CA, Ba5ic Violet 1 (
C, 1,42535), C, T, Ba5ic Vio
let 3 (C, 1, 42555) C, 1, Ba5
icViolet 10 (C, 1, 45170), C
,1,Ba5ic Violet 14(C,T',
42510), C, T, Ba5ic Blue
1' (C, 1°42025), C, 1, Ba5ic
Blue 3 (C, 1, 51005), C, T.

B'sic Blue 5 (C,'1.4'2140
), C,1,Ba5ic Blue 7(C,1,'
42595), C,1,Ba5ic Blue 7 (
C,1゜42585), C,1,Ba5ic Blue
9 (C, 1, 52015), C, T.

Ba5ic Blue 24 (C, 1,' 5203
0), C,1, Ba5ic Blue25 (C,1,
52025), C,1,Ba5ic Blue 2
B (C:, I.

ajo45), C, 1, Ba5ic Green 1
(C, 1, 42040), C, 1, Ba5ic Gre
en 4 (C,1,42000), C,I.

42510, C, 1, 45170, C, 1, Ba5
ic Blue 9 etc.). Lake pigments of these basic dyes (as lake forming agents, phosphotungstic acid,
Phosphormolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide,
ferrocyanide etc. ), C,1,5olven
tBlack 3 (ill:, 1.28150), Hansa Yellow c, (c, r.

11f180), C, 1, Morelant Black
k11,C,1,PigmentBlack1,
Gilt night, asphalt, etc.

and quaternary ammonium salts, such as benzylmethyl-
Organic tin compounds such as hexadecyl ammonium chloride, decyl-trimethylammonium chloride, dibutyltin oxide, metals of higher fatty acids, salts, glass, mica, inorganic fine powders such as zinc oxide, metal complexes such as EDTA and acetylacetone, etc. Polyamine resins such as vinyl polymers containing polyamines and condensation polymers containing amine groups.

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

Special Publication No. 41-20153, No. 43-275118,
44-fi397, 45-28478, etc., monoazo dye metal complex salts represented by the following general formula [wherein, N is Cr or co, and R and R2 are unsubstituted or substituted] a substituted phenylene residue, R3 and R4 represent residues of a coupling component that is unsubstituted or substituted with a substituent that couples at the ortho position of the metallizable group, and x1 and x2 are 10 -mata represents -COO-, x3 and x4 represent 10-1-NH- or -N-alkyl, [A]+ represents hydrogen ion, ammonium ion, aliphatic ammonium ion, alicyclic ammonium ion, Heterocyclic ammonium ion represents an alkali metal or alkaline earth metal. ] Dye and pigments such as nitrofumic acid and its salts or C, 1,14845 described in JP-A-50-133338.

and Special Publication No. 55-42752, Special Publication No. 511-41
No. 508, Special Publication No. 59-7384, Special Publication No. 59-73
Salicylic acid, naphthoic acid, etc. described in No. 85, etc.
Metal complexes of dicarboxylic acids such as Go, Cr, and Fe.

Sulfonated copper phthalocyanine pigment. Styrene oligomer with nitro groups and halogens introduced. 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.

Recently, there are some newly proposed products that are different from these, but none have surpassed dye-pigment-based products in terms of overall performance, and there are still examples of dyes using dyes, although they are still unsatisfactory. Almost.

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, uniform 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 used for development in a copying machine, as the number of copies increases, the charge control agent may decompose or change in quality, leading to 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 problem 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
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 disperse the charge control agent into the resin -L, a method is also used 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 at present, sufficient uniformity of charge has not yet been obtained for practical use.

Furthermore, most of the substances generally known as charge control agents have a dark color and cannot be incorporated into a bright chromatic developer.5) There is a problem.

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, when conventional charge control agents are used in toners, 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 (filming phenomenon), those that cause scratches on the surface of the photoreceptor or cleaning members such as cleaning blades, or promote wear of these members.

Furthermore, when conventional charge control agents are used in toners, many of them have a large effect on the thermal melting properties of the toners and reduce fixing performance. In particular, high temperature offset performance deteriorates.
In addition, there are some cases where the transfer plate increases the clinging property of the transfer plate to the roller during heat roll fixing and reduces the durability life of the roller.

As described above, there are many problems with conventional charge control agents, and there is a strong demand in the technical field to improve these, and although many improvement techniques have been proposed so far,
The reality is that nothing that is comprehensively satisfactory in practical terms has yet been found.

[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.

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 resides in a developer containing a compound represented by the following general formula [11].

X-X-...[1] In the c formula, Rl + R2+ R3 and R4 are hydrogen, a hydrocarbon such as an alkyl group, a cyclic alkyl group, an alkenyl group, an aryl group, an aralkyl group, an alkylene group, an arylene group, etc. represents either a substituent having a basic skeleton of represents a valent group, X- is CX-1Br-, I-, S'042-, SO32
-, NO3-, and C2O42- represent an anion of an organic acid.

The present inventors have discovered that the compound represented by the general formula [11] is thermally and temporally stable, has low hygroscopicity, and when contained in a developer, has a high quality charge that provides a developer with excellent electrophotographic properties. It was found to be a control agent.

Typical specific examples of the compound represented by the general formula [1] include the following.

Compound Example 4 Compound Example 5 SO42-, SO3'-, NO3- and 'J! 1%2
- It may be changed to any of the anions of nanoorganic acids.

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 30 parts by weight (more preferably 1 to 1 part by weight) per 100 parts by weight of the binder resin.
0 parts by weight).

In addition, when externally added, 0.0 parts by weight of resin
1 to 10 parts by weight is preferred.

It is also possible to use conventionally known charge control agents 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, nigrolene dye, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa Yellow G, rhodamine 6G, lake,
Any conventionally known dyes and pigments such as calcooil prolu, chrome yellow, quinacridone, benzidine yellow, rose bengal, triallylmethane dyes monoazo, 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 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 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 11 polymer and styrene-maleic acid ester copolymer; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyurethane, polyamide, epoxy resin, Examples include 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 polypropylene, polyethylene oxide, 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 phenol 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.

As carriers that can be used in the present invention, all known carriers can be used, such as iron powder, magnetic powders such as ferrite powder and nickel powder, glass beads, etc., and carriers whose surfaces have been treated with resin, etc. etc.

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. Metals like iron, cobalt, nickel, aluminum, cobalt, copper, iron, lead, magnesium, nickel, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium Examples include metal alloys and mixtures thereof.

These ferromagnetic materials preferably have an average particle size of about 0.1 to 2 IL, 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. 40 to 150 parts by weight.

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

To prepare the toner for developing an electrostatic image according to the present invention, the charge control agent according to the present invention is added to a vinyl or non-vinyl thermoplastic resin, a pigment or dye as a coloring agent, and a magnetic material 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, niegu, or extruder to make the resins mutually dissolve. Disperse or dissolve the Nuko dye, cool and solidify, then crush and classify to obtain an average particle size of 5~
20J1. of toner can be obtained.

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 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 have 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 photosensitive materials and copying machines are eliminated, and since the toner of the present invention is extremely superior, for example, toner damage during storage, which has been a major problem in the past, has been eliminated. 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, since there is little color disturbance caused by the charge control agent, it is possible to form color images with excellent colors when used as a color electrophotographic toner.

[Examples] The present invention will be specifically explained below using Examples, but these are not intended to limit the present invention in any way. All parts in the following formulations are parts by weight.

Example 1 Low molecular weight polyethylene wax 2-part compound example 1
2 parts of the 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 phase-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 20p. 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 IL.

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.
20, 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 found to have no dull color compared to the initial images.

Further, during durability, the above-mentioned filming phenomenon related to toner on the photoreceptor was not observed, 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 fuser 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. There wasn't.

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.
Fixation was performed 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 1.08, line drawings were scattered, and solid black was noticeably rough. Durability was investigated and the density decreased to 0.83 after 30,000 sheets.

During durability, after about 10,000 sheets, toner material began to form on the surface of the photoreceptor, forming a film in the form of stripes and appearing 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.

Example 2 A developer was obtained in the same manner as in Example 1, except that 2.3 parts of Compound Example 2.3 was used instead of Compound Example 1.2 parts, and an image was obtained by performing development, transfer, and fixing 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 3.2 parts of Compound Example 1.2 was used instead of Compound Example 1.2 parts, and images were 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 1 were obtained.

Example 4 A developer was obtained in the same manner as in Example 1, except that 4.2 parts of Compound Example 4.2 was used instead of Compound Example 1.2 parts, and images were 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 1 were obtained.

Example 5 Triiron tetroxide EPT-500 (manufactured by Toda Kogyo) 600 parts Low molecular weight polypropylene wax 2 parts Compound Example 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 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 JL. Ta.

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 commercially available copying machine (trade name NP-1502, manufactured by Canon ■) and outputted, good IC results were obtained, almost the same as in Example 1.

Example 6 A developer was obtained in the same manner as in Example 5, except that 2.3 parts of the compound example was used instead of 1.2 parts of the compound example, and images were formed in the same manner as in Example 5. Obtained.

The detailed results are shown in Table 1, and almost the same satisfactory results were obtained in Example 5''C.

Example 7 A developer was obtained in the same manner as in Example 5, except that 3.2 parts of the compound example was used instead of 1.2 parts of the compound, and images were 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 were obtained in Example 5°C.

Comparative example? 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 1.2 parts of Compound Example, and an image was obtained in the same manner. At room temperature and humidity, there is little fog, but the image density is 0.81
The line drawings were scattered, and the solid black was noticeably rough.

I checked the durability, and the density was 0.48 after 30,000 sheets.
and decreased.

In addition, the filming phenomenon during durability and the problem in the fixing process were almost the same as those in Comparative Example 1. Example 8 Copper phthalocyanine blue pigment 5 parts Low molecular weight polypropylene wax 29 parts Compound example 12 parts - 1- Materials were thoroughly mixed in a blender and then kneaded with two rolls heated to 150°C. The mixed material was coarsely pulverized using a natural number cold bridge and 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 201 L. .

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

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

When this developer was used to develop an image using the developing method shown in Figure 1, a good image with a bright blue color was obtained, and after 1500 images, the toner/carrier amount was 10g to 150g. However, there was almost no change in the image density, and after that, while replenishing toner,
A good image was obtained even if the image was printed up to three times.

To explain this developing method, in FIG. 1, 1 is an electrostatic image carrier, 2 is a toner carrier, 3 is a hopper, and 52
5 is a magnetic brush made of a magnetic particle-toner mixture, 58 is a toner thickness regulating blade, 50 is a fixed magnet, 6 is a developing bias, and 5 is 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 hover of 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 greater than the thickness of one toner layer, and the toner 5 on the toner carrier 2 is caused to fly onto the electrostatic charge 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 by making the gap between the toner and the toner layer larger than the thickness of the toner layer.

Table 1 shows the evaluation results for each example and comparative example.

Table 1 [Effects of the invention] (1) The amount of triboelectric charge between toner particles, between toner and carrier, or between toner and toner carrier such as a sleeve in the case of -component development is stable; In addition, the developer has a sharp and uniform triboelectric charge distribution and can be controlled to a charge amount suitable for the developing system used.

(2) A developer that enables faithful development and transfer of latent images.

(3) Even if the developer is used continuously for a long period of time, the initial characteristics can be maintained, and the developer can produce vivid chromatic images without toner aggregation or changes in charging characteristics.

(0) It is a developer with excellent long-term storage stability and good fixing properties.

(5) It is an easy-to-clean developer that does not stain, abrade, or scratch the electrostatic latent image surface.

[Brief explanation of drawings]

FIG. 1 is a schematic partial cross-sectional view for explaining an example of a developing device to which the positively chargeable toner according to the present invention can be applied. l... Electrostatic image holder, 2... Toner carrier, 5...
・Toner, 50...Magnet, 52...Magnetic brush, 5
8...Regulation blade.

Claims (1)

[Claims] (1) The following general formula ▲ Numerical formula, chemical formula, table, etc. ▼ [In the formula, R_1, R_2, R_3 and R_4 are hydrogen, alkyl group, cyclic alkyl group, alkenyl group, aryl group, aralkyl group, alkylene group, arylene Y represents either a substituent whose basic skeleton is a hydrocarbon such as a group, a heterocyclic group containing nitrogen, sulfur, or oxygen, or a substituent combining these; Y is R_1, R_2, R_3
and represents a divalent group having the same substituent as R_4, and X^- is Cl^-, Br^-, I^-, SO_4^2
^-, SO_3^2^-, NO_3^- and C_2O_
Represents any of the anions of 4^2^- organic acids. ] A toner for developing an electrostatic image, characterized by containing a compound represented by the following.