JPS61128255A - Electrostatic charge image developing developer - Google Patents

Abstract

PURPOSE:To obtain a developer stable in a triboelectrified amt. sharp and uniform in a triboelectrified amt. distribution, and controllable to a triboelectrified amt. suitable to a developing system to be used by incorporating a 1,2,4-triazole deriv. CONSTITUTION:The developer contains a triazole compd. stable with respect to heat and time, small in hydroscopicity, and a high-quality electrostatic charge controller capable of giving excellent electrophotographic characteristics to the developer contg. it, and it is represented by formula I, II, or III in which each of R1, R2, and R3 is, independent of each other, H, alkyl, cyclic alkyl, acyl, aryl, alkylene, aralkyl, alkoxy, or the like, each hydrocarbon optionally substd. or an amino, secondary, or tertiary amino group, each optionally substd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel developer 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. , they essentially form an electrostatic latent image by imparting a uniform electrostatic charge on a photoconductive insulator layer, irradiating the insulator layer with a light image, and then " In this technology, images are developed and visualized using fine powder called toner, and after the powder image is transferred to paper or the like as necessary, it is fixed using heat, pressure, solvent vapor, or the like.

The developing methods applied to these electrophotographic methods are broadly divided into dry developing methods and wet developing methods. The former is
The method is further divided into two types: a method using a two-component developer and a method using a -component developer. Two-component developing methods include a magnetic brush method using an iron powder carrier, a cascade method using a bead carrier, a fur brush method using fur, etc., depending on the type of carrier for conveying the toner.

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.

Conventionally, toners used in these development methods are fine powders in which dyes and pigments are dispersed in natural or synthetic resins. Finely pulverized particles of about 1 to 30 IL 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 currently known in the art include the following.

(1) A device that controls toner to have a positive charge.

Nigrosine, azine dyes containing an alkyl group having 2 to 16 carbon atoms (Japanese Patent Publication No. 42-1827), basic dyes (for example, G, 1.Ba5ic Yellow 2 (G,
1.41000), C, 1, Ba5ic Yellow
3, C,1,Ba5ic Red 1(G,i
45160), C,1,Ba5ic Red
9 (C, I.

42500), C, 1, Ba5ic Violet 1
(C,1,42535),C,1,Ba5ic Vi
olet 3 (G, 1.42555) C, 1, Ba
5icViolet 10 (C, 1, 45170),
G.1. Ba5ic Violet 14CC,1,
42510), C,1,Ba5ic Blue 1
(C, I.

42025), C,1,Ba5ic Blue 3 (
C, 1, 51005), C, I.

Bs1c Blue 5 (G, 1.42140), C
, 1, Ba5ic Blue 7 (G, 1. 4259
5), C,1,Ba5ic Blue 7 (C,1°42595), C,1,Ba5ic Blue 9 (
C, 1, 52015), G, I.

Ba5ic Blue 24 (C:, 1.52030
), C,1,Ba5ic Blue25 (C,1,5
2G25), C,1,Ba5ic Blue 2B
(C,1°44045), C,1,Ba5ic Gr
een 1 (C, 1, 42040), C, 1, Ba5
ic Green 4 (C, 1,42000),
C.I.

42510, CA, 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,
7 erocyanide, etc.), C, 1,5olve
ntBlack 3 (C, 1, 28150), Handy Yellow G (C, I.

11880), C, 1, Morelant Black
11, G, 1. Pig+wentBlack 1
, Gilt Night, Asphalt, etc.

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

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

Monoazo dye metal complex salts represented by the following general formula, described in Japanese Patent Publications No. 41-20153, No. 43-27598, No. 44-8397, No. 45-28478, etc. [wherein, X is Cr or CO] , R1 and R2 are unsubstituted or substituted phenylene residues, R
3 and R4 are unsubstituted or substituted with a substituent that couples at the ortho position of the metallizable group. , represents the residue of the coupled coupling component, xl and x2
は-o-:j:ri4t-GOO-wo, X3toXa 4*
-0-1-NH- or -N-alkyl-,
[AP represents a hydrogen ion, ammonium ion, aliphatic ammonium ion, alicyclic ammonium ion, heterocyclic ammonium ion, alkali metal or alkaline earth metal] Nitrohumic acid described in JP-A-50-133338 and its salt or C,1,148
45 and other dyes and pigments.

Metal complexes of salicylic acid, naphthoic acid, guicarboxylic acid such as Go, Cr, Fe, etc. described in Japanese Patent Publication No. 55-42752, Japanese Patent Publication No. 58-41508, Japanese Patent Publication No. 59-7384, Japanese Patent Publication No. 59-7385, etc. , sulfonated copper phthalocyanine pigments, nitro groups, styrene oligomers with halogens introduced, chlorinated paraffins, melamine resins, 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, 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 developed using 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 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 to achieve more uniform dispersion.For example, basic nigrosine dyes are treated with higher fatty acids and salt-formed to improve their compatibility with thermoplastic resins. 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 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.

Further, 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 a bright chromatic developer.

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

Therefore, when using toner under high temperature conditions, these
Since the charge control agent is hydrophilic, there is a problem in 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 toner support such as a sleeve,
Problems such as development fog, toner scattering, and carrier contamination are likely to occur. Furthermore, this problem becomes more noticeable when a large number of copies are made, and the result is that the copying machine is not suitable.

Furthermore, under high humidity conditions, the transfer efficiency of toner images decreases significantly, making many toners unusable. Due to the instability of charge control agents, they often undergo deterioration and become unusable.

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, or promote wear of these members.

Furthermore, when conventional charge control agents are used in toner, there are many that have a large effect on the heat-melting properties of the toner and reduce fixing performance, especially high-temperature offset performance, and transfer There are some that increase the clinging property to the rollers, and some that reduce the durability life of the rollers.

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.

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 properties even after 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 based on the following general formula % [3] [In the formula, R, , R2 and R3 are the same or different groups, hydrogen or an alkyl group, Either a substituent having a hydrocarbon basic skeleton such as a cyclic alkyl group, acyl group, aryl group, alkylene group, aralkyl group, or alkoxy group, or an amine group, or a substituted amine group such as a secondary or tertiary amine group This invention relates to a developer containing a triazole compound represented by the following.

These compounds are synthesized by known methods. The inventors discovered that the compound represented by the general formula [11, [21, or [3]] is thermally and temporally stable, has low hygroscopicity, and has excellent electrophotographic properties when contained in a developer. It was discovered that this is a high-quality charge control agent that provides a good developer.

Typical specific examples of compounds represented by general formula [1] or [21 or [31] include the following.

Compound Example (1) N-C-N(C2H5)2 Compound Example (2) N-G-GH3 Compound Example (3) Compound Example (4) H3 Compound Example (5) Compound Example (6) H2O-N -C -C2H5 Compound example (7) H2C-N-C-? , -GH3 Compound Example (8) 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. Although not limited, preferably binder resin 100
0.1 to 50 parts by weight (more preferably 1 part by weight)
~20 parts by weight).

In addition, when externally added, 0.0 parts by weight per 100 parts by weight of resin.
1 to 40 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, nigrosine dye, aniline blue, phthalocyanine blue, phthalocyanine green, 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, heptanoazo dyes, disazo dyes, and 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 acid copolymers and styrene-maleic ester copolymers: polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyurethane, polyamide, epoxy resin , 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 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.

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 such as aluminum, cobalt, steel, lead, magnesium, nickel, tin, and zinc; antimony, beryllium,
Alloys and mixtures of metals such as bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, and vanadium.

These ferromagnetic materials preferably have an average particle size of about 0.1 to 2 µl, 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 in an amount of about 20 to 200 parts by weight per 100 parts by weight of the resin component. The amount is 40 to 150 parts by weight.

Further, the toner of the present invention may be mixed with additives as necessary. Examples of additives include lubricants such as Teflon and zinc stearate, abrasives such as cerium oxide and silicon carbide, fluidity agents such as colloidal silica and aluminum oxide, anti-caking agents, and carbon black and tin oxide. Examples include conductivity imparting agents and 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. Alternatively, the dye is dispersed or dissolved, cooled and solidified, then crushed and classified to obtain an average particle size of 5~
You can get 20JL 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 monomer that is to constitute the binder resin to form an emulsified suspension and then polymerizing it. Methods such as a polymerization method for producing toner to obtain a toner can be applied.

[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 Carbon black (Mitsubishi Ben 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. The kneaded material was left to cool naturally, then coarsely pulverized with a cutter mill, and then finely pulverized with a jet airflow pulverizer. The powder was pulverized using a wind classifier and further classified using an air classifier to obtain a fine powder having a particle size of 5 to 20p.

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 l.

Further, the amount of triboelectric charge of the developer was measured by a conventional blow-off method. The value was +9.9 p, c/g.

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 completely dull compared to the initial images.

Also, 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 9-leaning 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 inspected and there were no scratches or damage to the rollers, and there was almost no dirt from offset toner, so there was no problem in practical use. There was no.

In addition, when the environmental conditions were set to 35°C and 85%, the image density was 1.17, 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 up to 10 degrees Celsius.
When a transferred image was obtained at a low temperature and low humidity of 10%, the image density was as high as 1.21, solid black was developed and transferred extremely smoothly, and the image was excellent with no splatters or voids. Durability was conducted under these environmental conditions, and even though copies were made continuously and intermittently, the density variation was ±0.2 up to 30,000 sheets, which was sufficient for practical use. Comparative Example 1 Compound Example (1) 2 A developer was obtained in the same manner as in Example 1, except that 2 parts of nigrosine dye was used instead of 1 part, and an image was obtained in the same manner by performing development, transfer, and fixing.

At room temperature, 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.

Further, during durability, after about 10,000 copies, toner material formed a thin film 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 68%.

When an image was obtained under the 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 omissions. I tried to take continuous images, but 3
The density was 0.53 after about 0.000 sheets, making it impractical.

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

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

Example 3 A developer was obtained in the same manner as in Example 1, except that 2 parts of Compound Example (3) was used instead of 2 parts of Compound Example (1), and images were obtained in the same manner by performing development, transfer, and fixing.

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 Example (4) was used instead of 2 parts of Compound Example (1), and images were obtained in the same manner by performing development, transfer, and fixing.

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 (Toda Kogyo type) 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 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 laps. 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 commercially available copying machine (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 Example (2) was used instead of 2 parts of Compound Example (1), and development, transfer, and fixing were carried out in the same manner. Got the image.

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 Example (3) was used instead of 2 parts of Compound (1), and images were formed in the same manner by performing development transfer and fixing. Obtained.

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 Example (1), 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.

Furthermore, 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 undesirable.

Further, 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.

The transfer efficiency was also as low as 63%. When an image was obtained under the conditions of 10° 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 0.59 after 30,000 sheets, making it impractical.

Example 8 Copper phthalocyanine blue pigment 5 parts Low molecular weight polypropylene 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 allowing the kneaded mixture 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 tiles. Obtained.

Further, the amount of triboelectric charge of the fine powder was measured by a conventional blow-off method. The value was +7.2 h c/g.

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 device shown in Figure 1, a good image with a bright blue color was obtained. However, there was hardly any change in the image quality, and after that, while replenishing toner,
A good image was obtained even after printing up to one frame.

To explain this developing method, in FIG. 1, ■ is an electrostatic image carrier, 2 is a toner carrier, 3 is a hopper, and
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, and the toner in the hover of 3 is taken in and coated on 2 in a uniform thin layer. Next, the toner carrier 2 and the electrostatic image carrier 1 are made to face each other with a gap greater than the thickness of one layer of toner, and the toner 5 on the 2 is separated by 1 layer.
The image is developed by flying onto the electrostatic charge image above.

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

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

Table 1 Table 2 [Effects of the invention 2] The toner produced by these methods can be used for development to visualize electrostatic images in electrophotography, electrostatic recording, electrostatic printing, etc. by conventionally known means. All of them can be used and have the following excellent 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 charge control and color tone disturbance due to one agent, it is possible to form color images with excellent colors when used as a color electrophotographic toner.

[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 (2)

[Claims] (1) A developer for developing electrostatic images characterized by containing a 1,2,4-triazole derivative. (2) The above 1,2,4-triazole derivative has the following general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [1], ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [2] or ▲ Mathematical formulas, chemical formulas ,
There are tables, etc. ▼ [3] [In the formula, R_1, R_2 and R_3 are the same or different groups, and are hydrogen, an alkyl group, a cyclic alkyl group, an acyl group, an aryl group, an alkylene group, an aralkyl group, or an alkoxy group. The electrostatic charge according to claim 1, which is a compound represented by a substituent having a hydrocarbon as a basic skeleton, a primary amino group, or a substituted amino group of a secondary or tertiary amino group. Developer for image development.