JPS61194453A - Electrostatic charge image developing toner - Google Patents

Abstract

PURPOSE:To enable triboelectrification to be controlled with high characteristics by incorporating a specified compd. CONSTITUTION:Cerium compd. such as cerous acetate is added to an electrostatic charge image developing toner contg. a binder resin as a constituent, in the amt. of 0.1-10pts.wt. per 100pts.wt. of the binder resin, and the addition of it permits triboelectrification amts. among toner particles, between toner particles and carrier particles, and in the case of using a one-component type developer, between the toner particles and a toner holder, such as a sleeve, to be stabilized, sharp and uniform in its distribution, so, triboelectrification control characteristics to be enhanced, its amt. to be controlled to that suitable to the development system, accordingly, development and transferring in high fidelity to a latent image to be executed, the toner to be unaffected by the change of temp. and humidity, and a stable image to be reproduced and further, a sharp chromatic color image to be obtained, cleaning to be facilitated, and high-temp. offset at the time of fixing, etc., to be prevented.

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.

[Conventional technology]

Conventionally, as an electrophotographic method, U.S. Patent No. 2,287.69
■- issue, Special Publication No. 42-23910, and Special Publication No. 4
Various methods are described in Japanese Patent No. 3-24748, etc., but in short, these methods include applying a uniform electrostatic charge to a photoconductive insulating layer and irradiating the insulating layer with a light image. An electrostatic latent image is formed, and then this latent image is developed and visualized using a fine powder called toner in this technology. After transferring the powder image to paper etc. as necessary, it is transferred by heat, pressure, or solvent vapor. This is to fix the problem.

The developing methods applied to these electrophotographic methods include:
Broadly speaking, there are dry development methods and wet development methods. The former method is further divided into a method using a two-component developer and a method using a -component developer. Two-component developing methods include:
Magnetic brush method using iron powder carrier, heap
There are a cascade method using a carrier, a fur brush method using fur, etc.

In addition, components-based development methods include the powder cloud method, in which toner particles are sprayed, and the contact development method, in which toner particles are brought into direct contact with the electrostatic latent image surface. (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; There is the MagneDry method, which develops by bringing a conductive toner into contact with the electrostatic latent image surface.

Conventionally, as the I-ner applied to these developing methods, fine powders in which dyes and pigments are dispersed in natural or synthetic resins have been used. For example, particles obtained by dispersing a colorant in a binder resin such as polystyrene and pulverizing the particles to about 1 to 30 particles are used as toner. As the magnetic toner, one containing magnetic particles such as magnetite is used. In the case of a system using a so-called two-component developer, the toner is usually mixed with carrier particles such as glass beads and iron powder.

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

In order to make the toner retain an electric charge, it is possible to utilize the triboelectricity of the resin that is a component of I-toner, but in this method, the toner's chargeability is small, so the image obtained by development is prone to fogging. It will be one of a kind. Therefore, in order to impart desired triboelectric chargeability to the toner, dyes, pigments, and even charge control agents that affect chargeability are added to the toner.

Now, examples of charge control agents known in the art include the following.

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

Nigrosine, azine dyes containing an alkyl group having 2 to 16 carbon atoms (Special Publication No. 4:!-1627), basic dyes (e.g. C, r, Ba5ic Yellow 2 (C
,1,41000),C,1,Ba5ic Yellow
w 3 , G, 1. Ba5ic Red 1 (C
:, 1゜45180), C-1, Ba5ic Red
9 (C,T, 42500), C,I.

Ba5ic Violet I (C, 1, 42535
) ,C,1,Ba5icViolet 3 (C,1
,42555), C,1,Ba5ic Viole
tlo(C,1,45170),C,1,Ba5ic
Violet 14 (C,I.

42510), C, 1, Ba5ic Blue 1
(C, 1, 42025), C, I.

Ba5ic Blue 3 (C, 1,5100
5), C,1,Ba5ic Blue5 (C,1,
42140), C,1,Ba5ic Blue 7 (
C.I.

42595), C, 1, Ba5ic Blue 9
(C, 1, 52015), C, I.

Ba5ic Blue 24 (C, 1, 52030)
,C,l Ba5ic Blue25 (C,1,5
2025), G,1. Ba5ic Blue 2
B (C, I.

44045), C, 1, Ba5ic Green
1 (C:, 1. 42040), G, 1.
Ba5ic Green 4 (C, 1,420
00), C, I.

42510, C,1,45170, etc. Lake pigments of these basic dyes (lake forming agents include phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannin ugliness, lauric acid, gallic acid, ferricyanide, ferrocyanide, etc.), G ,
1.5olvent Black 3 (C, 1, 28
150), Hansa Yellow G (C, 1, 11680),
C,1,MordlantBlack 11,C,1,
Pigment Black 1, Gilt Night, Asphalt, etc.

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

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

Metal complex salts of monoazo dyes described in Japanese Patent Publications Nos. 41-20153, 43-27588, 44-8397, and 45-28478.

Dyes and pigments such as nitrofumic acid' and its salts or G, 1.14845 described in JP-A-50-133338. Special Publication No. 55-42752, Special Publication No. 58-415
No. 013, Special Publication No. 59-7384, Special Publication No. 58-73
Salicylic acid, naphthoic acid, etc. described in No. 85, etc.
Metal complexes of guicarboxylic acid such as Go, Or, Fe, etc.

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 of them have surpassed dye-pigment-based products by -1-1 in overall performance, and dyes are still used, although they are still unsatisfactory. Most are examples.

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. In addition, it is easily decomposed or deteriorated due to decomposition during thermal kneading, mechanical impact, thick rubbing, 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 decomposes or changes in quality, which may cause deterioration of the toner during durability.

Furthermore, since it is extremely difficult to uniformly and uniformly disperse these charge control agents in thermoplastic resins, they have the fatal drawback of causing a difference in the amount of frictional charge between the toner particles obtained by pulverization. have. For this reason, various methods have been used to achieve more uniform dispersion. for example,
Basic nigrosine dyes are used by forming salts with higher fatty acids in order to improve their compatibility with thermoplastic resins, but unreacted fatty acids or salt dispersion products often form on the toner surface. The toner particles are exposed to the toner and contaminate the carrier or toner carrier, causing a decrease in the fluidity of the toner, fogging, and a decrease in image density. Alternatively, to improve the dispersion of these charge control agents into the resin,
There is also a method in which charge control agent powder and resin powder are mechanically pulverized and mixed in advance and then hot-melted and kneaded. However, the inherent poor dispersion cannot be avoided, and at present, sufficient uniformity of charge has not yet been obtained for practical use.

Further, most of the substances generally known as charge control agents have a dark color and 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 melt-kneading,
The dye is exposed on the toner surface.

Therefore, when the toner is used under high-temperature conditions, it has the disadvantage that a good quality image cannot be obtained because these charge control agents are wood-philic.

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. Moreover, this problem becomes a noticeable phenomenon when copies are made many times, and the result is practically unsuitable for copying machines.

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

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

Furthermore, when conventional charge control agents are used in 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 rollers are found to deteriorate the performance, increase the clinging of the transfer paper to the roller during heat roll fixing, and reduce the durable life of the roller.

As described above, conventional charge control agents have many drawbacks.
There is a strong demand in the technical field to improve these.
Although many improved techniques have been proposed so far,
The reality is that nothing that is comprehensively satisfactory in practical terms has yet been found.

[Problem that the invention seeks to solve]

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

The object of the present invention is to stabilize frictional electrification between toner particles, between toner and carrier (in the case of component development), between toner and carriers such as toner sleeves, etc.
Another object of the present invention is to provide a developer which has a sharp and uniform triboelectric charge distribution and whose charge level can be controlled to suit the developing system used.

The other target is a developer that performs development and transfer that is faithful to the i-idea, i.e., 4iJ of toner adhesion in the back ground area during development, which prevents fogging and toner flying around the edges of latent images. No problem, high image density 7
The purpose of the present invention is to provide a developer with a high 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 can produce stable images unaffected by changes in temperature and humidity, and in particular to improve transfer efficiency without causing scattering or transfer dropouts during transfer at high or low humidity. The goal is to provide high quality developer.

Still another object is to provide a bright I1 color 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 is easy to clean and does not damage, abrade, or scratch the electrostatic latent image surface.

Still another object is to provide a developer with good fixing properties;
In particular, the object of the present invention is to provide a developer that does not cause problems such as high-temperature offset.

[Means for solving problems]

The present invention resides in an electrostatic image developing toner containing a binder resin as a constituent component, which is characterized by containing a cerium compound.

The present inventors have discovered that a cerium compound is thermally and temporally stable, has low hygroscopicity, and is a high-quality charge control agent that provides a developer with excellent electrophotographic properties when included in a developer. We have arrived at the present invention.

Typical specific examples of cerium compounds that can be used in the present invention include the following.

[Compound example]

1, Ce(CH3COO)3' H2O2, Ce(SO
4) 2 3, Ce(10:+)4 4, GeF4 5, Ce(OH)n Ei, Ce(NO3)4 These compounds are synthesized by known methods.

For example, compound (1) is produced as follows.

10 g of cerium oxide was dissolved in 500 ml of 50% acetic acid aqueous solution while heating, and then water bathed at 75°C.
Second, water is evaporated and precipitated.

Generally, it is preferable that the above-mentioned compound is used for toner preparation as a particle size having an average particle size in the range of 10 to 0.1 watts, particularly 5 to 0.1 watts.

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 to be used is determined by the type of binder resin, the presence or absence of additives used as necessary, and the I-ner manufacturing method, including the dispersion method. Although not limited to, preferably binder resin 100
0.1 to 10 parts by weight (more preferably 0 parts by weight)
．． (5 to 5 parts by weight).

In addition, when externally added, 0.0 parts by weight per 100 parts by weight of resin.
1 to 10 parts by weight is preferred.

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

Coloring agents used in the present invention include carbon black, lamp black, iron black, ultramarine blue, nigrosine dye, acholine blue, phthalocyanine blue, fucrocyanine green, Hansa Yellow G, Rotamin 6G Lake,
Calco oil blue, chrome yellow, quinacridone,
Any conventionally known dyes and pigments such as benzidine yellow, rose bengal, triallylmethane dyes, monoamine dyes, disazo dyes and pigments can be used alone or in combination.

The binder resin used in the present invention includes polystyrene,
Monopolymers of styrene and its substituted products such as poly-P-chlorostyrene and polyvinyltoluene; styrene-P-chlorostyrene co-ffl combination, styrene-propylene polymer, styrene-vinyltoluene copolymer, styrene-
Vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-acrylic ethyl copolymer, styrene-methyl acrylate copolymer, styrene-acrylic octyl copolymer, styrene-methacrylic methyl copolymer , styrene-methacrylic m-ethyl copolymer, styrene-butyl methacrylate copolymer, styrene-α-
Methyl chlormethacrylate copolymer, styrene-acryloni)/lyl copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-
butadiene copolymer, styrene-isoprene copolymer,
Styrenic copolymers such as styrene-acrylonitrile-indene copolymer, styrene-maleic copolymer, styrene-maleic ester copolymer; polymethyl methacrylate-1, polymethyl methacrylate-1, poly Vinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyurethane, polyamide, epoxy resin, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenolic resin, aliphatic or alicyclic hydrocarbon resin, aromatic family petroleum resin,
Examples include chlorinated paraffin and paraffin wax, which can be used alone or in combination.

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

Polyolefins (low molecular weight polyethylene, low molecular weight polypropylene, saturated polyethylene, polytetrafluoroethylene, etc.), epoxy resins, polyester resins, styrene-butadiene copolymers (monomer ratio 5-30:!35-70)
), olefin copolymers (ethylene-acrylic acid copolymer, ethylene-acrylic ester copolymer, ethylene-methacrylic ester 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 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.

All known carriers can be used in the present invention, including magnetic powders such as iron powder, ferrite powder, and nickel powder, glass beads, etc., and carriers whose back surfaces are treated with resin, etc. Things can be given.

Furthermore, the toner of the present invention can further contain a magnetic material and be used as a magnetic toner. The magnetic material El contained in the magnetic toner of the present invention includes magnetite, hematite,
Iron oxide such as ferrite. Metals such as iron, cobalt, nickel, or these metals such as aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manquine, selenium, titanium, tungsten, and vanadium. Examples include alloys of such metals and mixtures thereof.

These ferromagnetic materials preferably have an average particle size of about 0.1 to 2 mm, 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 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 improvers such as colloidal silica and aluminum oxide, anti-caking agents, and carbon black. , conductive adhesives such as tin oxide, 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 mixed with a vinyl or non-vinyl thermoplastic resin, a pigment or dye as a coloring agent, a magnetic material as necessary, Additives etc. in ball mill and other 1.4
After mixing sufficiently with a mixing machine, the resins are melted, kneaded, and kneaded using a heat kneading machine such as a heated roll, kneader, or extruder to make the resins mutually soluble, and pigments or dyes are dispersed in the mixture. Alternatively, a toner having an average particle size of 5 to 20 particles can be obtained by dissolving, cooling and solidifying, and then pulverizing and classifying.

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 intermediate that constitutes the binder resin to form an emulsified suspension and then polymerizing it. Methods such as a method of combining toner particles, a method of combining toner particles, etc. can be applied.

Toners produced by these methods can be used for developing to visualize electrostatic images in electrophotography, electrostatic recording, electrostatic printing, etc. by any conventionally known means, and can be used as follows: It has excellent effects.

That is, the amount of frictional charge between toner particles is uniform, and the amount of charge can be easily controlled. In addition, the toner is extremely stable, with no variation or decrease in the amount of triboelectric charge due to deterioration during use. For this reason, the above-mentioned development fog, l.
In addition to eliminating problems such as toner scattering, electrophotographic photosensitive materials, and contamination of copying machines, the toner of the present invention is extremely superior, so it does not cause toner aggregation, clumping, or agglomeration during storage, which was a major drawback in the past. It is a toner that can be stored for a long time without causing phenomena such as low-temperature flow, and has excellent abrasion resistance, fixing properties, and adhesion of toner images.

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

〔Example〕

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

Example 1 Styrene/butyl acrylate ('80/20) copolymer 100 parts (weight average molecular weight MW: approximately 300,000) Carbon black (Mitsubishi #44) 10 parts Paper molecular weight polyethylene wax 2 parts Compound (1) 2
After thoroughly mixing the materials listed in Part-J- with a blender, heat at 150°C.
The mixture was kneaded using two heated rolls. After letting the kneaded mixture cool naturally,
After coarsely pulverizing it with a cutter mill, it was 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 pL.

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.

Next, a negative electrostatic charge image is formed on the OPG photoconductor by a conventionally known electrophotographic method, and this is powder developed using the magnetic brush method using the developer described in "2" to form a toner image. The images were transferred onto a paper and heat-fixed. The resulting transferred image had a sufficiently high density, no fogging, and no toner scattering around the image, resulting in a good image with high resolution. ” Transfer images were created continuously using the developer described above to examine durability, but the transferred images after 30,000 copies were also completely unchanged compared to the initial images. Ta.

Further, during durability, the above-mentioned filming phenomenon related to toner on the photoreceptor was not observed at all, and no problems were found in the cleaning process. Also, there were no troubles in the fixing process at this time, and at the end of the 30,000-sheet durability test, I observed the fuser and found no scratches or damage to the rollers, and there was almost no dirt on the offset toner, so Tenkawa J had no problems at all. There wasn't.

In addition, when the environmental conditions were set to 35°C and 85%, the image density was almost unchanged from normal temperature and humidity, and a bright image was obtained without fogging or scattering, and the N magnetism was 30%.
There was almost no change up to ,000 sheets.

Next, when a transferred image was obtained at 15° C. and 10% low temperature and humidity, the image density was sufficiently high, solid black was developed and transferred extremely smoothly, and the image was excellent with no scattering or hollow spots. Durability was carried out under these environmental conditions, and the density fluctuation was ±0.2 up to 30,000 copies, which was sufficient for practical use even though copies were made continuously and intermittently.

Comparative Example 1 In place of 2 parts of compound (I), nigrosine dye (Nigerorane Base Ex manufactured by Orient Chemical Industry Co., Ltd.) z-;? A developer was obtained in the same manner as in Example 1 except that B was used, and development, transfer, and
Fixation was performed and an image was obtained in the same manner.

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

Also, during durability, after about 10,000 sheets, a film formed on the surface of the photoreceptor (2. Toner 4A) formed in the form of a stripe and began to appear as a line 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, when chipping occurs, the fixed image tends to get caught up in the fixing roller during the fixing process, and there is a problem in peelability against the roller.

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

When images were obtained under conditions of 15°C and 10%, image a
The degree of printing was as low as 0.91, and there were splatters, fogging, roughness, and 11 transfer defects. Continuous image formation was performed, but the density became 0.53 after about 30,000 sheets, making it impractical.

Example 2 A developer was obtained in the same manner as in Example 1 except that 3 parts of compound (2) was used instead of 2 parts of compound (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 satisfactory results almost the same as in Example 1 were obtained.

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

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

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

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

Example 5 Styrene/butyl acrylate-1. (80/20) copolymer 100 parts (weight average molecular weight MW: approximately 300,000) Triiron tetroxide EPT-500 (manufactured by Toda Kogyo) 60 parts Paper molecular weight Polypropylene wax 2 parts Compound (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 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 fine powder with a particle size of 5 to 20 colors. Obtained.

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

This toner is used in a commercially available copier (product name NP-1502,
Example 1
Almost the same good results were obtained.

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

The detailed results are shown in Tables 1 and 2, and satisfactory results substantially similar to those of Example 5 were obtained.

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

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

Comparative Example 2 An image was obtained in the same manner as in Example 5, except that 2 parts of benzylmethyl-hexadecyl ammonium chloride was used instead of 2 parts of compound (1) in Example 5, and 45% of the developer was used. At room temperature and humidity, there is little fog, but the image density is 0.
At 81, the line drawings were scattered and the solid black was rough. I checked the durability, but the density was 0 after 30,000 sheets.
．． The score was as low as 48.

Furthermore, the above-mentioned filming phenomenon during durability and problems during fixing were almost the same as in Comparative Example 1, and were unsatisfactory.

The image source IH' was as low as 0.72 under the conditions of 35°C and 185% (1), and fogging, scattering, and roughness increased, making it unusable. The transfer efficiency was also low. When an image was obtained under the conditions of I5°C and 110%, the image density was as low as 0.73, and there was severe scattering, fogging, roughness, and noticeable transfer omissions. Continuous image formation was performed, but the density became 0.59 after 30,000 sheets, making it impractical.

Example 8 Styrene/butyl acrylate-1 (80/20) copolymer 100 parts (average molecular weight Mw: approximately 300,000) Copper phthalocyanine blue pigment 5 parts Low molecular weight polypropylene wax 2 parts Compound (1) 2 parts J- 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 roughly pulverized using a Cantermill, then pulverized using a pulverizer using a jet stream, and further classified using an air classifier to obtain a fine powder with a particle size of 5 to 20 IL. It's t-ri.

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

When images were developed using this developer using the development method described below, good images with a bright blue color were obtained, and after 1500 images, the amount of toner/carrier was 10 g.
Even when the weight was 750 g, there was almost no change in image density, and after that, images were printed on up to 30,000 sheets while replenishing toner, and good images were obtained.

This developing method will be explained using Figure i1.

By rotating the toner carrier 2, a magnetic brush 52 made of a carrier skewer toner mixture formed on the toner carrier 2 is circulated, and the toner in the hopper 3 is taken in and spread uniformly onto the carrier 2. Apply a layer coat. Next, the toner carrier 2 and the electrostatic image carrier (2) are placed opposite to each other with a gap larger than the thickness of the toner, and the toner 5 on the carrier 2-1- is transferred to the electrostatic charge image -1- on the electrostatic image carrier IJ-. Let it fly and develop.

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

The evaluation results of each example and comparative example are shown in Tables 1 and 2. In the table, O indicates good, O△ indicates slightly good, △ indicates slightly poor, and × indicates poor.

Table 1 〔Effect of the invention〕 The effects obtained by the present invention are as follows.

By using the toner for developing electrostatic images of the present invention, (1) the amount of triboelectric charge between toner particles, between toner and carrier, between toner and toner carrier such as a sleeve in the case of -component development is stabilized; , and the triboelectric charge distribution becomes sharp and uniform, allowing the charge amount to be controlled to suit the developing system used.

(2) It is possible to develop and transfer a latent image faithfully, and even when used continuously for a long period of time, the initial characteristics are maintained, and toner aggregation and charging characteristics do not change.

(3) Stable images that are unaffected by changes in temperature and humidity can be reproduced, and images in vivid chromatic colors can be obtained.

(4) The cleaning process is facilitated without staining, abrading, or scratching the electrostatic latent image surface, and the fixing properties are excellent, and there are no problems even with high-temperature offsets, which tend to cause troubles.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an example of a developing device to which the positively chargeable toner according to the present invention can be applied. DESCRIPTION OF SYMBOLS 1... Electrostatic image holder, 2... I/ner carrier, 3...
... Hopper, 5... Toner 6... Bias, 50... Magnet 52... Magnetic brush, 58.
...Regulation blade.

Claims (1)

[Scope of Claims] 1) An electrostatic image developing toner comprising a binder resin as a constituent component, the toner containing a cerium compound. 2) The toner for developing electrostatic images according to claim 1, wherein the cerium compound is cerous acetate. 3) The content of cerous acetate is 0.1 to 10 parts by weight based on 100 parts by weight of the binder resin.
The toner for developing electrostatic images described in Section 1.