JPH0366667B2 - - Google Patents

Description

Detailed Description of the Invention Technical Field The present invention relates to a material or member having an improved function for imparting charge to a toner used for developing an electrostatic image in electrophotography, electrostatic recording, electrostatic printing, etc. That is, it relates to a charge imparting material (herein, the word "material" is used to include granular materials in addition to members having a regular shape).

BACKGROUND ART Conventionally, as an electrophotographic method, U.S. Patent No. 2297691
No., Special Publication No. 1972-23910, and Special Publication No. 43-
Various methods are described in Japanese Patent No. 24748, etc., but they basically involve applying a uniform electrostatic charge onto a photoconductive insulating layer and irradiating the insulating layer with a light image. An electrostatic latent image is formed, and then the latent image is developed and visualized with fine powder called toner in the art, and if necessary, after transferring the powder image to paper etc., heating, pressure, or solvent treatment is performed. Fixing is carried out using steam or the like.

The developing methods applied to these electrophotographic methods can be roughly divided into dry developing methods and wet developing methods. The former is further divided into methods using a two-component developer and methods using a one-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.

Examples of one-component 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 (contact development, or toner development method). (also referred to as development), a 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; magnetic conductivity; There is the MagneDry method, which develops by bringing toner into contact with the electrostatic latent image surface.

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

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

In order to charge the toner, it is also possible to use only the triboelectricity of the resin, which is a component of the toner, but with this method, the toner's chargeability is small, so the image obtained by development is prone to fogging. ,
It becomes unclear. Therefore, in order to impart desired triboelectric charging properties to the toner, charge control agents such as dyes and pigments that enhance the charging properties are added.

However, in order to impart chargeability to the toner by adding these additives, these additives must be exposed to some extent on the toner surface. Therefore, due to friction between the toners, collision with the carrier, friction with the electrostatic latent image carrier, etc., these additives fall off the toner surface, contaminating the carrier, etc., and damaging the electrostatic latent image carrier, such as the photoreceptor. This may cause contamination of the belt or drum. As a result, the charging property deteriorates, and as development operations are repeated, the deterioration progresses, resulting in a decrease in image density, a decrease in fine line reproducibility, an increase in fog, and other practical problems.

The above problems can be improved by improving the affinity and dispersibility of the toner binder and additives such as dyes and pigments that impart chargeability or charge control agents. Surface treatment to increase the toner often results in a decrease in charge imparting properties, and if the toner is mechanically sheared strongly and dispersed finely, the proportion of the additive that appears on the toner surface decreases, and the chargeability tends to be insufficient. Become. Based on these facts, additives that can impart chargeability to toner to a practically satisfactory level are:
It is very limited and there are only a few that have been put into practical use. In particular, in order to obtain not only black and white images but also color images, it is preferable that the charge control agent added to the toner be colorless, and in this case, there are almost no practically satisfactory charge control agents.

In view of these circumstances, we aim to improve the charge imparting properties to toner not only by using toner additives, but also by improving the conveyance, regulation, and friction of carriers, sleeves, doctor blades, etc. that come into contact with toner during the development process. A member (herein,
It has also been proposed that this can be achieved by improving the charge imparting properties of a charge imparting material (collectively referred to as a "charge imparting material") to toner. In other words, the term "charge-imparting material" as used herein refers to a material that can come into contact with the toner during or prior to the development process and impart a charge necessary for development to the toner or provide an auxiliary charge to the toner. It is a member.

This method of actively imparting a charge to the toner using a charge imparting material almost eliminates the need for the toner to contain additives to improve its charging properties, thus providing an essential improvement over the above-mentioned problems. can be measured. For example, contamination sources such as carrier particles and photoreceptors are essentially reduced, so that repeated development operations do not reduce chargeability or disturb latent images. Furthermore, the color toner can be easily charged without impairing its color tone.

These charge-imparting materials such as carriers, sleeves, and doctor blades must not only have strong charge-imparting ability, but also be durable and able to withstand toner friction. For example, it is desired that the carrier be used for a long period of time without replacement, and the sleeve is required to have the same level of durability as the main body of the developing machine.

OBJECT OF THE INVENTION An object of the present invention is to provide a charge imparting material that solves the above-mentioned problems.

A further object of the present invention is to provide a charge imparting material that imparts an appropriate negative charge to toner.

A further object of the present invention is to provide a charge imparting material whose performance does not deteriorate even after long-term use.

A further object of the present invention is to provide a charge-imparting material that provides images with excellent fine line reproducibility and gradation.

A further object of the present invention is to provide a charge imparting member suitable for charging color toner.

Summary of the Invention The present inventors have arrived at the present invention as a result of research to achieve the above-mentioned object.

That is, the present invention has the following general formula: In the formula, R ₁ , R ₂ , R ₄ , and R ₅ are hydrogen, halogen, a nitro group, an amino group that may have a substituent, an alkyl group (C ₁ to C ₁₈ ), and a substituent. R ₁ and R ₂ and R ₄ and R ₅ represent a sulfamoyl group that may have substituents, and R ₃ ,
R ₆ is hydrogen, alkyl group (C ₁ to _{C 9} ), benzyl group,
or represents a phenyl group which may have a substituent, and Me represents a divalent metal.

A charge imparting material for developing an electrostatic image is characterized in that it has a chelate compound represented by the following at least on its surface.

The present invention will be explained in more detail below. In the following descriptions, "parts" and "%" represent quantitative ratios.
are based on weight unless otherwise specified.

Specific Description of the Invention Typical specific examples of the chelate compound used in the charge imparting material of the present invention include the following.

These compounds are extremely stable and can be synthesized by known methods.

Some synthesis examples are shown below.

Synthesis Example 1 Synthesis of nickel anthranilic acid chelate 54.8 g (0.4 mol) of anthranilic acid was added to 1 mol of water.
was added to a solution containing 16 g (0.4 mol) of caustic soda and dissolved completely. This solution was heated to 80°C. 25.9 g (0.2 mol) of nickel chloride was dissolved in 150 ml of water, and this aqueous solution was gradually added dropwise to the above solution. After the dropwise addition was completed, stirring was continued at 80° C. for 1 hour, and then the mixture was allowed to cool while stirring, and then cooled to room temperature. After cooling, it was filtered and washed with water until the pH of the liquid became neutral. After washing with water, it was dried at 90°C. As a result, about 65 g of pale light blue powder was obtained.

Synthesis Example 2 Synthesis of 5-methylanthranilate zinc chelate 27.3 g (0.2 mol) of zinc chloride was added to 500 ml of ethylene glycol. 5-methylanthranilic acid
60.4 g (0.4 mol) was slowly added to the above solution.
After the addition, stirring was continued for 2 hours at 130°C, and then the mixture was dispersed in water 3. After dispersion, the solution was filtered and washed with water until the pH of the solution became neutral.
After washing with water, it was dried at 90°C. the result,
Approximately 40 g of white powder was obtained.

Synthesis Example 3 - Synthesis of nickel methylanthranilic acid chelate 23.8 g (0.1 mol) of nickel acetate was added to 500 ml of ethyl cellosolve and stirred. Heat to 50℃,
30.2 g (0.2 mol) of N-methylanthranilic acid was slowly added. After reacting for 2 hours while refluxing at about 130°C, the mixture was dispersed in water 2. After 1 hour, it was filtered and washed with water until the pH of the liquid became neutral. Drying was performed at 90°C. As a result, about 29 g of pale light blue powder was obtained.

Synthesis Example 4 Synthesis of N-phenylanthranilic acid cobalt chelate 24.9 g (0.1 mol) of cobalt acetate was added to 500 ml of dimethylformamide and completely dissolved. Heat to 50℃ and add 42.6g of N-phenylanthranilic acid.
(0.2 mol) was added gradually. After reacting for 3 hours while refluxing at about 145°C, heating was stopped.
When cooled to 100℃, disperse in 2 parts of water and 1
After an hour, it was filtered and washed with water. When washing with water, the pH of the liquid is
This was done until it became neutral. Drying was performed at 90°C. As a result, about 40 g of pale reddish-gray powder was obtained.

The above compound generally has an average particle size of 10 to 0.01 μm, particularly 2 μm, although it depends on the form of the charge imparting material to be applied.
It is preferable to provide the charge-imparting material in the form of particles of ~0.1μ.

These compounds can be applied by dipping, spraying, brushing, etc. to the base material of the charge-imparting material with a coating solution obtained by dissolving or dispersing them in a solvent or dispersion medium together with a binder resin if necessary. When the base material is in the form of carrier particles, the carrier particles are coated on the base material by a method such as dipping and mixing with the above-mentioned coating liquid and then drying, or a method such as coating with a fluidized bed of a direct mixture of this and the above-mentioned compound. The charge imparting material of the present invention can be obtained by forming a coating layer of the compound. Alternatively, the material may be directly melt-kneaded with a binder resin and extruded and laminated onto a base material to obtain a charge-imparting material having a coating layer containing the material. Furthermore, these compounds may be contained in a moldable resin and molded into the shape of carrier particles, sleeves, or doctor blades to form a charge-imparting material.

Common binder resins or molding resins can be used. For example, polystyrene, polyacrylic ester, polymethacrylic ester, polyacrylonitrile, rubber resins such as isoprene and butadiene, polyester, polyurethane, polyamide, epoxy resin,
Rosin, polycarbonate, phenolic resin, chlorinated paraffin, polyethylene, polypropylene, silicone resin, Teflon, derivatives thereof, copolymers thereof, or mixtures thereof can be used. After coating or molding, these resins can be made to have a crosslinked structure as necessary to improve the durability of the surface layer of the charge-imparting material.

When using a binder resin or molding resin, the above compound is contained in an amount of 0.5 to 200 parts per 100 parts of the binder resin or molding resin.
In particular, it is preferable to use it in a proportion of 2 to 100 parts.

When coating the surface of the charge-imparting material, it is necessary to appropriately control the amount of coating or application of the compound, but it is preferable that the material is 0.01 mg/cm ² to 10 mg/cm ^{2 .}
The range is preferably 0.1 mg/cm ² to 2 mg/cm 2 .
^cm2 is good.

In addition to the above-mentioned compounds, ceramic powders such as silica powder, aluminum oxide, cerium oxide, and silicon carbide may also be used as fillers in the series of cases described above. Furthermore, a conductivity imparting agent such as carbon black or tin oxide may be used to adjust the conductivity. Further, in order to prevent the spent toner from accumulating on the sleeve or carrier surface, a release agent such as a fatty acid metal salt, vinylidene fluoride, etc. may be used.

All known carriers can be used as the base material for the carrier-type charge-imparting material, and metals such as iron, nickel, aluminum, and copper;
Alloys or powders or particles of metal compounds containing metal oxides, as well as glass, SiC, BaTiO ₂ ,
Ceramic powder or particles such as SrTiO ₂ are used. Further, examples include those whose surfaces have been treated with a resin, resin powder, or resin powder containing a magnetic material.
The average particle size is preferably about 20 to 250μ. The chelate compound of the present invention is 0.5 to 300 per kg of carrier.
g, preferably 2 to 200 g.

Furthermore, the base material of the charge imparting material in the form of a sleeve or doctor blade may generally be metals or alloys such as iron, aluminum, stainless steel, or nickel, or non-metallic compounds such as ceramics or plastics, which can generally be used as a sleeve or doctor blade. can be used.

On the other hand, as toners to be used in combination with the charge imparting material of the present invention as described above, substantially all toners that have been used as conventional toners for developing electrostatic images can be effectively used. That is, both non-magnetic and magnetic toners can be used. More specifically, the toner is a colored fine particle containing a colorant in a binder resin, and may contain magnetic powder if necessary. Furthermore, these toners may contain small amounts of charge-imparting substances, such as dyes, pigments, or so-called charge control agents, in order to impart a more efficient charge, and may also contain flow agents such as colloidal silica. , abrasives such as cerium oxide, strontium titanate, and silicon carbide, and lubricants such as metal stearate and vinylidene fluoride. It may also contain conductivity imparting agents such as carbon black and tin oxide.

As the developing method using the charge imparting material and toner of the present invention described above, substantially all developing methods using a two-component developer or a single-component developer can be used.

For example, magnetic brush development method, cascade development method, fur brush development method, so-called microtoning development method using magnetic substance-containing resin powder as a carrier, development method using resin powder as a carrier, so-called jumping development method, or non-magnetic toner. This is a jumping development method.

Effects of the Invention As described above, according to the present invention, there is provided a charge imparting material for imparting a charge to a toner for developing an electrostatic image, in which a compound having a specific structure is present as a charge control agent on the surface. . In particular, the compound of the present invention not only has excellent charge control properties and stability against heating or moisture absorption, but also can be applied to the surface of a charge-imparting material by coating or kneading and dispersing it. Provides a good charge imparting material with excellent durability when used in friction with other materials. Therefore, by using this charge-imparting material, it is possible to obtain essential improvements over the various problems that occur when the charge-imparting material is mixed only into toner to improve its charging characteristics.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 100g of the above compound example (1) was dissolved and dispersed in MEK1, and an iron powder carrier (particle size: 250~
400mesh) was dispersed and stirred in a ball mill for about 30 minutes.

After drying this iron powder carrier mixture and completely removing the solvent, light agglomerations were loosened to obtain a carrier-like charge imparting material according to the present invention.

Separately, a toner was prepared according to the following formulation without adding any charge control agent.

Styrene 100 parts (product name D-125: manufactured by Etsuo Chemical Co., Ltd.) Carbon black 6 parts (product name Raven 3500: Cabot Co., Ltd.) The above materials were kneaded, crushed, and classified to a particle size of 1 to 1.
Aligned to 30 μm.

The weight ratio of this toner and the carrier is 10:100.
was mixed to prepare a developer.

The amount of triboelectric charge of this developer was measured by the blow-off method and was found to be -8.8 μc/g.

When this developer was used to produce images on a Canon NP-5000 copying machine, there was no change in image density even after a durability test of 50,000 sheets, and fine line reproducibility and gradation were good. There was also no fogging.

Example 2 100 g of polymethyl methacrylate resin was dissolved in 1 xylene, and 50 g of Compound Example (2) was mixed therein.
This was mixed with the same iron powder carrier as in Example 1,
By drying, a carrier having a charge imparting effect was obtained.

When this was used in combination with toner in the same manner as in Example 1, the amount of triboelectric charge of the toner was -7.8 μc/g, and when image formation was performed using this,
The resulting images remained strong even after a durability test of 50,000 sheets, showing the same good image density, fine line reproducibility, and gradation adjustment as the initial image, and no fogging.

Example 3 A solution was prepared by dissolving 100 g of polymethyl methacrylate resin in 1 xylene and mixing 50 g of Compound Example (2). Add Canon NP-
Dip a developing sleeve (stainless steel) for 400RE and add 0.1 mg/cm ² to 0.6 mg/cm ² on the sleeve.
I wore a coat.

This sleeve was installed in the original developing machine.

The toner was prepared according to the following recipe using a general kneading and pulverizing method.

Poly(styrene-butyl methacrylate) w=300000 100 parts Mold release agent 4 parts (Product name PE-130: manufactured by Hoechst) Magnetic powder 60 parts (Product name BL-200: manufactured by Titan Kogyo Co., Ltd.) The diameter was adjusted to 1μ to 30μ.

Using this toner, we conducted an image reproduction durability test using Canon's NP-400RE.

With durability of 50,000 sheets, there was no change in the image from the beginning, fine line reproducibility, gradation adjustment were good, and there was no fogging.

Further, when the surface potential on the sleeve was measured, it was -41V, confirming that the toner was completely negatively charged.

Example 4 A solution was prepared by dissolving 80 g of polycarbonate resin in 1 xylene and further mixing 20 g of Compound Example (1).

Dip the developing sleeve (made of aluminum) of the developing machine of the blue cartridge for Canon PC-20 into this solution, and add 0.1 mg/cm ² onto the sleeve.
A coating of ~0.5 mg/ ^cm2 was applied.

This sleeve was installed in the original developing machine. On the other hand, a toner was prepared according to the following recipe.

Poly(styrene-butylmeth) (Crylate) w=150000 100 copies Mold release agent 4 parts (Product name PE-130: Manufactured by Hoechst) 6 parts blue colorant (phthalocyanine pigment) The particle size of the produced toner was adjusted to 1μ to 30μ.

Using this toner and a developing machine equipped with the above-mentioned sleeve, PC-20 was modified to enable reversal development, and durable images were produced.

As a result, until the toner ran out, there was no change in the image, and a clear blue image with good fine line reproducibility and gradation adjustment was obtained. Furthermore, when the surface potential of the toner on the sleeve was measured, it was -29V, indicating that it was negatively charged.

Examples 5 to 8 The chelate compound examples used in Examples 1 to 4 are, in order, Compound Example (2) (Example 5), 〃 (3) (Example 6), 〃 (4) (Example 7) , 〃 (5) (Example 8), The same procedure as Examples 1 to 4 was performed except that chelate was used for replacing , and satisfactory results were obtained.

In addition, the correspondingly measured triboelectric charge amount and surface potential were as follows.

Example 5 -8.3μc/g Example 6 -6.9μc/g Example 7 -29V Example 8 -34V Examples 9 to 12 The chelate compounds used in Examples 1 to 4 were, in order, the following compound examples ( 6) (Example 9), (7) (Example 10), (8) (Example 11), (9) (Example 12), Examples 1 to 4 except for replacing with the chelate of The same procedure was carried out and satisfactory results were obtained.

In addition, the correspondingly measured triboelectric charge amount and surface potential were as follows.

Example 9 -10.3μc/g Example 10 -7.7μc/g Example 11 -38V Example 12 -41V Examples 13 to 16 The chelate compounds used in Examples 1 to 4 were given in order. Compound Example (10) (Example 13), 〃 (11) (Example 14), 〃 (12) (Example 15), 〃 (13) (Example 16), Same as Examples 1 to 4 except for replacing with the chelate of carried out and obtained satisfactory results.

In addition, the correspondingly measured triboelectric charge amount and surface potential were as follows.

Example 13 -9.2μc/g Example 14 -8.3μc/g Example 15 -28V Example 16 -29V Examples 17 to 20 The chelate compounds used in Examples 1 to 4 were replaced with the above compound examples ( 20) (Example 17), (21) (Example 18), (24) (Example 19), (25) (Example 20), Examples 1 to 4 except for replacing with the chelate of The same procedure was carried out and satisfactory results were obtained.

In addition, the correspondingly measured triboelectric charge amount and surface potential were as follows.

Example 17 -7.4μc/g Example 18 -10.1μc/g Example 19 -42V Example 20 -33V Examples 21 to 24 The chelate compounds used in Examples 1 to 4 were given in order, respectively. Compound Example (27) (Example 21), 〃 (28) (Example 22), 〃 (30) (Example 23), 〃 (31) (Example 24), Same as Examples 1 to 4 except for replacing with the chelate of carried out and obtained satisfactory results.

In addition, the correspondingly measured triboelectric charge amount and surface potential were as follows.

Example 21 -9.3μc/g Example 22 -7.8μc/g Example 23 −41V Example 24 -43V

Claims (1)

[Claims] 1. General formula In the formula, R ₁ , R ₂ , R ₄ , and R ₅ are hydrogen, halogen, a nitro group, an amino group that may have a substituent, an alkyl group (C ₁ to C ₁₈ ), and a substituent. R ₁ and R ₂ and R ₄ and R ₅ represent a sulfamoyl group that may have substituents, and R ₃ ,
R ₆ is hydrogen, alkyl group (C ₁ to _{C 9} ), benzyl group,
or represents a phenyl group which may have a substituent, and Me represents a divalent metal. A charge imparting material for developing an electrostatic image, characterized in that it has a chelate compound represented by the following on at least its surface. 2. The charge imparting material according to claim 1, which is in the form of carrier particles. 3. The charge imparting material according to claim 1, which is in the form of a cylindrical sleeve. 4. The charge imparting material according to claim 1, which is in the form of a doctor blade.