JPS61246761A - Charge donor for developing electrostatic charge image - Google Patents

Abstract

PURPOSE:To give proper negative charge to a toner and to prevent it from deterioration for a long period by attaching a chelate compd. of a specified substd. anthranilic acid to the surface of a charge donor, such as carrier particles or the like. CONSTITUTION:The chelate compd. of the substd. anthranilic acid to be used is represented by the formula shown on the right in which R1-R4 are each H, alkoxy, aryloxy, arylthio, or aralkylthip; and M is a divalent metal atom, such as Ni, Co, Zn, or Cu. This compd. is dissolved and dispersed, and mixed with fine iron carrier particles to attach it on their surfaces and it may be added to the surfaces of a cylindrical sleeve or a doctor blade, thus permitting the obtained toner to be enhanced in charge controllability and durability by the presence of said compd. on the surface of the charge donor.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a material with an improved function for imparting charge to toner used for developing electrostatic images in electrophotography, electrostatic recording, electrostatic printing, etc. The present invention relates to a member or member, that is, a charge imparting material (herein, the word “material” is used to include a single particulate material in addition to a member having a regular shape).

11 Indigo technology Previously, as an electrophotographic method, U.S. Patent No. 2,297.69
1, Special Publication No. 42-23910, and Special Publication No. 43
Various methods are described in Japanese Patent Application No. 24748, etc., but these methods basically apply a uniform electrostatic charge onto a photoconductive insulating layer and irradiate the insulating layer with a light image to generate static electricity. An electrostatic latent image is formed, and then the latent image is developed and visualized using a fine powder called toner in the art, and if necessary, the powder image is transferred to paper or the like, and then heated, pressurized, or by solvent vapor, etc. 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 is further divided into 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, methods belonging to the -component development method include the powder cloud method, in which toner particles are sprayed, and the contact development method (contact development, or toner development method, in which toner particles are brought into direct contact with the electrostatic latent image surface for development. 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.

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 particles are used as toner. Also as a magnetic toner.

In place of or in addition to the above dyes or pigments, materials containing magnetic particles such as magnetite are used. In the case of a system using a so-called two-component developer, the above-mentioned toner is usually made of glass beads,
It is used mixed with carrier particles such as 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 that 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 and is unclear. Become something. Therefore, in order to impart desired triboelectric charging properties to the toner, charge control agents such as dyes, 1lli additives, etc. 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 surface of the toner. Therefore, friction between the toners, collision with the carrier, and static These additives fall off from the toner surface due to friction with the latent image carrier.

Contamination of the carrier, etc., and contamination of the electrostatic latent image holding member 1, such as the photoreceptor belt or drum, etc. occur. 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 problem mentioned above is the affinity between the toner binder and additives such as dyes and pigments that impart chargeability or charge control agents.
This can be improved by improving the dispersibility, but this often results in a decrease in charge imparting properties, which require surface treatment to increase the affinity for these additives.Additionally, if strong mechanical shear is applied to finely disperse the toner, the toner surface The proportion of additives released into the battery decreases, and charging properties tend not to be sufficiently imparted. For these reasons, there are very few additives that can impart chargeability to toner to a practically satisfactory level.
There are only a few that have been put to 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.In this case, there are few that are practically satisfactory. There is no condition.

In view of these circumstances, the improvement of the charge imparting characteristics to toner is not only achieved by toner additives, but also by improving the conveyance, regulation, or friction of carriers, sleeves, doctor blades, etc. that come into contact with toner during the development process. members (in this specification, these are collectively referred to as "charge imparting materials")
It has also been proposed that this can be achieved by improving the charge imparting properties to the 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 can provide the toner with a charge necessary for development or provide an auxiliary charge with the toner. It is a member.

This method of actively imparting charge to the toner using a charge imparting material eliminates the need for the toner to contain additives to improve charging characteristics, so it is possible to improve the quality of the toner to address the above-mentioned problems. For example, causes of contamination such as carrier particles and photoreceptors are reduced physically, so repeated development operations do not reduce chargeability or disturb latent images, and furthermore, they do not harm the color tone of color toners. It can be easily charged.

Here, charge imparting materials such as carriers, sleeves, doctor blades, etc. must not only have a strong charge imparting ability, but must also be durable and able to withstand friction with the toner.

For example, the carrier is desired to be used for a long period of time without being replaced, and the sleeve is required to have the same durability as the main body of the developing machine.

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 material suitable for charging color toners.

11 11 The charge imparting material of the present invention was developed to achieve the above-mentioned objects.

That is, the electrostatic charge developing agent of the present invention has the following general formula [I
] It is characterized by having a chelate compound of substituted anthranilic acid represented by the following on at least the surface.

(In the formula, R+, R2, Rs, R4 are hydrogen atoms, alkoxy groups, aryloxy groups, aralkyloxy groups,
are the same or different groups selected from alkylthio groups, arylthio groups, and aralkylthio groups (however, not all of them are hydrogen atoms; M represents a divalent metal atom). The chelate compound of substituted anthranilic acid represented by formula [1] (hereinafter collectively referred to as "substituted anthranilic acid chelate") is thermally stable for 1 hour, has low hygroscopicity, and can be coated or kneaded. The present invention was achieved by discovering that by making it present on the surface of the charge-imparting material by including the charge-imparting material, a charge-imparting material that has good durability against friction with toner and has excellent electrophotographic properties can be provided. It is.

The present invention will be explained in more detail below. In the following description, "parts" and "1%" expressing quantitative ratios are based on weight unless otherwise specified.

・; The substituted anthranilic acid chelate used as a charge control agent in the present invention is represented by the above general formula [I], and the meanings of each symbol in the formula are also as described above. R+, R2, R2, R4 are selected from the group below. That is, hydrogen atoms (however, not all hydrogen atoms); alkoxy groups such as methoxy, nidoxy, propoxy, butoxy, and octoxy groups; aryloxy groups such as phenoxy and chlorophenoxy groups; benzyloxy groups; Methylbenzyloxy group, chlorobenzyloxy group.

7-ralkyloxy groups such as phenethyloxy groups; Furkylthio groups such as methylthio, propylthio, and hexylthio groups; 7-arylthio groups such as phenylthio, methylphenylthio, ethylphenylthio, and chlorphenylthio groups; benzylthio and chlorbenzyl thio group,
Examples include 7-ralkylthio groups such as methylbenzylthio groups.

Further, M represents a divalent metal atom, and specific examples include Ni, Co, Zn, Cd, Cu, Fe, Mn, Hg,
Pb etc. are listed.

Typical specific examples of the substituted anthranilic acid chelate represented by the general formula [I] include the following.

[Compound example] (1)　　　　　　　　　.

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

For example, the substituted anthranilic acid chelate (nickel methoxyanthranilic acid chelate) exemplified above as compound (1) is produced as follows.

Add nickel acetate to ethyl cellosolve, mtt-heat to 50°C and slowly add 5-methoxyanthranilic acid. After reacting for 2 hours under reflux at about 130°C, the mixture is dispersed in water. After 1 hour, filtration and water washing are carried out.Washing is continued until the pH of the φ liquid becomes neutral.Drying is carried out at 90°C to obtain compound (1).

Other compounds can also be obtained by substantially the same operations as above.

The substituted anthranyl chelate generally has an average particle size of 10 to 0.0, although it depends on the form of the charge imparting material to which it is applied.
It is preferable to form the charge imparting material as particles of IIL, particularly 2-O,IIL.

These substituted anthranilic acid chelates can be dissolved or dispersed in a solvent or dispersion medium together with a binder resin if necessary, and a coating liquid obtained can be applied to the base material of the charge imparting material by dipping, spraying, brushing, etc. Alternatively, if the base material is in the form of carrier particles, it is mixed with the above coating liquid by immersion and then dried, or coating with a fluidized bed of a direct mixture of this and the substituted anthranilic acid chelate, etc. The charge imparting material of the present invention can be obtained by forming a coating layer of the substituted anthranilic acid chelate on a base material by the method described above.Also, the charge imparting material of the present invention can be obtained by melt-kneading directly with a binder resin and extrusion laminating on the base material. You may obtain a charge imparting material having a coating layer containing,
Furthermore, these compounds may be incorporated into a moldable resin and molded into the shape of carrier particles, sleeves or doctor blades to provide a charge-imparting material.

As the binder resin or molding resin, common resins can be used. For example, polystyrene, polyacrylic ester, polymethacrylic ester, polyacrylonitrile, rubber resins such as isoprene and butadiene, polyester, polyurethane, polyamide, Epoxy resins, rosins, polycarbonates, phenolic resins, chlorinated paraffins, polyethylene, polypropylene, silicone resins, 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 amount of the substituted anthranilic acid chelate is 0 per 100 parts of the binder resin or molding resin.
．． It is preferably used in a proportion of 5 to 200 parts, particularly 2 to 100 parts.

When coating the surface of the charge imparting material, it is necessary to appropriately control the coating or coating amount of the substituted anthranilic acid chelate, but if the material is 0.01 mg/cm2
~ long/cm2 is good, but preferably 0.1
mg/cm2 to 2 mg/cm2 is good.

In addition to the substituted anthranilic acid chelate, ceramic powder such as silica powder, aluminum oxide, cerium oxide, or silicon carbide may be used as a filler in the above series of cases.

In addition, a conductivity imparting agent such as carbon black or tin oxide may be used in the conductive rR node.Furthermore, in order to prevent the product of spent toner on the sleeve or carrier surface, a release agent or the like may be used, for example. Fatty acid metal salts, vinylidene fluoride, etc. may also be used.

All known carriers can be used as the base material of the charge imparting material in carrier form, including iron.

Powder or particles of metals such as nickel, aluminum, copper, alloys, or metal compounds including metal oxides, glass, 5iC1BaTj02, S r
Ti02 A" Which ceramic powder or particles are used? Also, examples include those whose surfaces have been treated with resin, resin powder, or resin powder containing magnetic material. The average particle size is 20-25
oIL level is suitable. Furthermore, as the base material for the charge imparting material in the form of a sleeve or doctor blade, metals or alloys such as iron, aluminum, stainless steel, and nickel, non-metallic compounds such as ceramics and plastics, etc. are generally used. Anything that can 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, toner is colored fine particles containing a coloring agent in a binder resin! Yes, if necessary
These toners may contain a magnetic powder, and furthermore, these toners may contain a small amount of a charge-imparting substance 1, such as a dye, a pigment, or a so-called charge control agent, in order to impart a charge more efficiently. It may contain a fluidizing agent such as silica, an abrasive agent such as cerium oxide, strontium titanate, and silicon carbide, a lubricant such as metal stearate, and vinylidene fluoride, and a conductive material such as carbon black and tin oxide. It may contain a imparting agent.

As the developing method using the above-mentioned charge imparting material and toner of the present invention, substantially all developing methods using a two-component developer or a one-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 development method. This is a jumping development method that uses toner for development.

As described above, according to the present invention for imparting a charge to an electrostatic charge image developing toner, an electrostatic charge containing a substituted anthranilic acid chelate having a specific structure as a charge control agent is present on the surface. A charge imparting material for imparting charge to a toner for developing a charge image is provided. In particular, the substituted anthranilic acid chelate of the present invention not only has excellent charge control properties and stability against heating and moisture absorption, but also has the ability to be present on the surface of a charge-imparting material by coating or kneading and dispersing it. This provides a good charge imparting material with excellent durability when used in friction with toner.

Therefore, by using this charge-imparting material, it is possible to improve the various problems that arise when a charge-imparting agent is mixed only into toner to improve its charging characteristics.

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

A long amount of the compound (1) was dissolved and dispersed in MEKlj, and an iron powder carrier (particle size: 250 to 400 me
sh) IKg was dispersed and stirred in a ball mill for about 30 minutes.

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

A toner was prepared using a separate primary formulation without adding any charge control agent.

Styrene ioo part (product name D
-125: manufactured by Etsuo Chemical Co., Ltd.) 6 parts of carbon black (trade name: Raven 3500: Capot Co., Ltd.) Mix the above materials,
The powder was crushed and classified to have a particle size of 1 to 30 m.

This toner and the carrier were mixed at a weight ratio of 10:ioo to prepare a developer.

The triboelectric charge amount of this developer was measured by the blow-off method and was -7.8 gc/g.

When this developer was used to produce an image using a Canon NP-5000 copying machine, the results were so and so.

Even in the durability test of 0 sheets, there was no change in image density, and the fine line reproducibility was good and the single gradation property was also good. There was also no fog.

"Shigoko" 100% polymethyl methacrylate resin in 17% xylene
g was dissolved, and 50 g of the above compound (1) was further mixed therein. This was mixed with the same iron powder carrier as in Example 1 and dried to obtain a carrier having a charge imparting effect.

When this was used in combination with a toner in the same manner as in Example 1, the amount of triboelectric charge of the toner was -8.87LC/g, and when an image was produced using this, the resulting image was so, ooo In the durability test of the sheet, it showed good image density, fine line reproducibility, and single gradation, just like the initial image, and no fogging.

Text JfU 跣] Polymethyl methacrylate resin 100% in xylene 17%
A solution was prepared by dissolving [ and further mixing 50 g of the above compound (2). Add Canon NP-400RE to this solution.
Dip the developing sleeve (made of stainless steel) for
0゜1 mg/cm” ~0.6 rng/on the sleeve
I applied a cm2 coat.

This sleeve was placed in the original developing machine.

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

Poly(styrene-butylmeth) 100 parts
) Mw=300,000
Mold release agent 4 parts (product name P
E-130: Manufactured by Hoechst) Magnetic powder
60 parts (trade name: BL-200, manufactured by Titan Kogyo Co., Ltd.) of the prepared toner had a particle size of 1JL to 30IL.

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

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

In addition, when the surface potential on the sleeve was measured, it was -38v.
It was confirmed that the toner was completely negatively charged.

A solution was prepared by dissolving 80 g of polycarbonate resin in xylene 11 and further mixing 20 g of the compound (2).

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/cm2 to 0 on the sleeve.
, 5 mg/cm2 coated.

This sleeve was placed in the original developing machine.

On the other hand, a toner was prepared according to the following recipe.

Poly(styrene-butylmeth) 100 parts
) Mw=150,000
Mold release agent 4 parts (product name P
E-130: Hoechst) blue colorant
6 parts (phthalocyanine pigment) The prepared toner had a particle size of IJL to 30 L.

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

As a result, there is no change in one image until the toner runs out.
A clear blue image with good fine line reproducibility and single gradation was obtained. Furthermore, we measured the surface potential of the toner on the sleeve.
It was 7V and was negatively charged.

χ"L mineral": YuJ Compounds (3) (Example 5) and /I (Example 6), each of which is the compound (1) or (2) used in Examples 1 to 4, respectively.

Compound (4) (Example 7).

〃 (Example 8), carried out in the same manner as Examples 1 to 4 except for replacing
I got satisfactory results.

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

Example 5 knee 7.8μc/g // 6: -11, 3μc/g //7: -43V //8 knee 29V (2) respectively described above in order as Compound (5) (Example 9), (Example 10), Compound (6) (Example 11), and (Example 12).

The procedure was carried out in the same manner as in Examples 1 to 4, except that
I got satisfactory results.

Further, the correspondingly measured amount of triboelectric charge and surface potential were as follows.

Example 9 Knee 13.1μc/g /I 10 : -7, 3c/g // 11 : -51V // I 2 : -38V -13 to 16 The above compound used in Examples 1 to 4 (1 ) or (2), respectively, in order of compound (7) (Example 13), // (Example 14), compound (8) (Example 15), and 11 (Example 16).

The procedure was carried out in the same manner as in Examples 1 to 4, except that
I got satisfactory results.

Further, the correspondingly measured amount of triboelectric charge and surface potential were as follows.

Example 13 Knee 7.9pc/g // 14: -8, 81LC/g // 15
: -24V // l6 : -35V

Claims (1)

[Scope of Claims] 1. A charge-imparting material for developing electrostatic images, characterized in that it has a chelate compound of substituted anthranilic acid represented by the following general formula [I] on at least its surface. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R_1, R_2, R_3, R_4 are selected from hydrogen atoms, alkoxy groups, aryloxy groups, aralkyloxy groups, alkylthio groups, arylthio groups, and aralkylthio groups. The charge-imparting material according to claim 1, which is the same or different groups (however, not all of them are hydrogen atoms; M represents a divalent metal atom). 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.