JPH0646315B2 - Charge-imparting material for electrostatic image development - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a material or member having an improved function for imparting an electric charge to a toner used for developing an electrostatic charge image in electrophotography, electrostatic recording, electrostatic printing and the like. That is, the present invention relates to a charge imparting material (here, the term “material” is used to include a granular material in addition to a member having a fixed shape).

BACKGROUND ART Conventionally, US Pat. No. 2,297,69 has been used as an electrophotographic method.
No. 1, JP-B-42-23910, and JP-B-43.
No. 24748, etc., various methods are described. In short, they apply a uniform electrostatic charge on a photoconductive insulating layer and irradiate the insulating layer with a light image to obtain a static image. An electrostatic latent image is formed, then the latent image is developed and visualized by 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. It is to fix.

As a developing method applied to these electrophotographic methods,
It is roughly classified into a dry development method and a wet development method. The former is further divided into a method using a two-component developer and a method using a one-component developer. Among the two-component developing methods, there are a magnet brush method using an iron powder carrier, a cascade method using a bead carrier, a fur brush method using a fur, etc., depending on the type of carrier that carries the toner.

The one-component developing method includes a powder cloud method in which toner particles are sprayed, a contact developing method in which toner particles are directly brought into contact with an electrostatic latent image surface for development (contact development, or toner development). (Also referred to as development), a jumping development method in which toner particles are not directly contacted with the electrostatic latent image surface, but the toner particles are charged and fly toward the latent image surface by the electric field of the electrostatic latent image, magnetic conductivity. There is a magnetic dry method in which toner is brought into contact with the electrostatic latent image surface to develop the toner.

As a toner applied to these developing methods, a fine powder in which a dye or a pigment is dispersed in a natural or synthetic resin is conventionally used. For example, particles in which a colorant is dispersed in a binder resin such as polystyrene and finely pulverized to about 1 to 30 μm are used as a toner. As the magnetic toner, one containing magnetic particles such as magnetite instead of or in addition to the above-mentioned dye or pigment is used. In the case of a system using a so-called two-component developer, the toner as described above is usually used by being mixed with carrier particles such as glass beads and iron powder.

Further, positive or negative electric charges are given to the toner in advance depending on the polarity of the electrostatic latent image to be developed.

To impart an electric charge to the toner, it is possible to use only the triboelectric chargeability of the resin, which is a component of the toner, but in this method the toner chargeability is small, so the image obtained by development is easily fogged and is not clear. It will be Therefore, in order to impart a desired triboelectric charging property to the toner, a charge control agent such as a dye or a pigment which enhances the charging property is 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, these additives fall off from the toner surface due to friction between toners, collision with a carrier, friction with an electrostatic latent image holding member, etc., and contamination of the carrier or the like, electrostatic latent image holding member such as a photoconductor. Contamination of the belt or drum occurs. As a result, the charging property becomes poor, and further, the deterioration progresses as the developing operation is repeated, the image density is lowered, the reproducibility of fine lines is decreased, and the fog is increased.

The above-mentioned problems are caused by the affinity between the binder of the toner and the additive such as the dye / pigment or the charge control agent that imparts the charging property,
It can be improved by improving dispersibility, but surface treatment to increase the affinity for these additives often lowers the charge imparting property. The proportion of the additive that comes out decreases, and the chargeability tends to be insufficiently imparted. From these things, the additives capable of imparting the chargeability to the toner to the extent that they are practically sufficiently satisfied are very limited,
Very few have been put to practical use. In particular, in order to obtain not only a black and white image but also a color image, the charge control agent added to the toner is preferably colorless, and in this case, there are few practically satisfactory charge control agents.

In view of such circumstances, the improvement of the property of imparting charge to the toner is not achieved only by the additive of the toner, but the conveyance, regulation or friction of the carrier, the sleeve, the doctor blade, etc. which come into contact with the toner during the developing process. Member (In the present specification, these are collectively referred to as “charge-imparting material”)
It is also proposed to improve the charge imparting property to the toner (refer to). That is, in the present specification, the “charge-imparting material” is a material or a material which can contact the toner prior to or during the development step to impart the charge necessary for the development to the toner or to supplement the charge. It is a member.

In the method of positively imparting the electric charge to the toner by the electric charge-imparting material, it is almost unnecessary to add the additive for improving the charging characteristic to the toner, and therefore, the essential improvement to the above-mentioned problems is achieved. Can be measured. For example, the causes of contamination of carrier particles, photoconductor, etc. are essentially reduced, and therefore, the charging property is not deteriorated and the latent image is not disturbed by repeated development operations. Further, the color toner can be easily charged without impairing the color tone.

Here, the charge-imparting material such as the carrier, the sleeve, the doctor blade, and the like must not only have a strong charge-imparting ability, but must also withstand the friction with the toner and be durable. For example, it is desired that the carrier be used without being replaced for a long period of time, and the sleeve is required to have durability as high as that of the developing machine main body.

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

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

A further object of the present invention is to provide a charge-imparting material that does not deteriorate in performance after being used for a long period of time.

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

A further object of the present invention is to provide a charge-giving material suitable for charging a color toner.

SUMMARY OF THE INVENTION The charge-imparting material of the present invention was developed to achieve the above-mentioned object.

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

(In the formula, R ₁ , R ₂ , R ₃ , and R ₄ are the same or different groups selected from hydrogen atom, alkoxy group, aryloxy group, aralkyloxy group, alkylthio group, arylthio group, and aralkylthio group (provided that , All are not hydrogen atoms); M represents a divalent metal atom.) That is, the present inventors have found that a chelate compound of a substituted anthranilic acid represented by the general formula [I] (hereinafter, comprehensively). (Also called "substituted anthranilic acid chelate") is thermally and temporally stable and has little hygroscopicity. By allowing it to exist on the surface of the charge-imparting material by coating or kneading, it is possible to reduce friction with the toner. On the other hand, they have reached the present invention by finding that they provide a charge-imparting material having good durability and excellent electrophotographic characteristics.

Hereinafter, the present invention will be described in more detail. In the following description, “part” and “%” representing the quantitative ratio are based on weight unless otherwise specified.

DETAILED DESCRIPTION OF THE INVENTION The substituted anthranilic acid chelate used as the charge control agent in the present invention is represented by the above general formula [I], and the meaning of each symbol in the formula is also as described above, but a little remark is made. , The substituents R ₁ , R ₂ , R ₃ , and R ₄ are selected from the following groups. That is, a hydrogen atom (however, not all hydrogen atoms); an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, an octoxy group, an aryloxy group such as a phenoxy group, a chlorphenoxy group; a benzyloxy group, Aralkyloxy groups such as methylbenzyloxy group, chlorobenzyloxy group and phenethyloxy group; alkylthio groups such as methylthio group, propylthio group and hexylthio group; phenylthio group, methylphenylthio group, ethylphenylthio group,
An arylthio group such as a chlorophenylthio group; an aralkylthio group such as a benzylthio group, a chlorobenzylthio group, and a methylbenzylthio group.

M represents a divalent metal atom, and specific examples thereof include Ni, Co, Zn, Cd, Cu, Fe, Mn, and H.
g, Pb and the like.

The following are typical specific examples of the substituted anthranilic acid chelate represented by the general formula [I].

[Example of compound] (1) (2) (3) (Four) (Five) (6) (7) (8) 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 the compound (1) is prepared as follows.

Add nickel acetate to ethyl cellosolve and stir. 5
Heat to 0 ° C. and slowly add 5-methoxyanthranilic acid. After reacting for 2 hours under reflux at about 130 ° C., it is dispersed in water. After 1 hour, excessive washing with water is performed until the pH of the liquid becomes neutral. Dry 9
The compound (1) is obtained at 0 ° C.

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

The substituted anthranilic acid chelate generally has an average particle size of 10 to 0.0, although it depends on the form of the charge-imparting material to be applied.
It is preferable that the particles are provided in the form of a charge-giving material in the form of particles of 1 μ, particularly 2 to 0.1 μ.

These substituted anthranilic acid chelates are applied to the base material of the charge-imparting material by dipping, spraying, brush coating, etc., with the coating solution obtained by dissolving or dispersing it in a solvent or a dispersion medium together with a binder resin if necessary. Alternatively, when the base material is in the form of carrier particles, it is dried by mixing it with the above coating solution and then drying, or by coating with a fluidized bed a direct mixture of this and the substituted anthranilic acid chelate. If the coating layer of the substituted anthranilic acid chelate is formed on the base material, the charge imparting material of the present invention can be obtained. Also, directly with the binder resin,
The charge-giving material may be obtained by melt-kneading and extruding and laminating on a base material to obtain a coating layer containing the material. Further, these compounds may be contained in a moldable resin, which may be molded into a shape of carrier particles, sleeves or doctor blades to be used as a charge imparting material.

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

When the binder resin or the molding resin is used, it is preferable to use the substituted anthranilic acid chelate in an amount of 0.5 to 200 parts, particularly 2 to 100 parts, relative to 100 parts thereof.

When applied to the surface of the charge-imparting material, wherein at coating or coating amount of a substituted anthranilic acid chelate should be controlled appropriately, the material is 0.01 mg / cm ² to 10
The range of mg / cm ² is good, but preferably 0.1 mg / cm ^{2 to 2} mg
/ cm ² is good.

Through the series of cases described above, silica powder, ceramic powder such as aluminum oxide, cerium oxide, or silicon carbide may be used as a filler together with the substituted anthranilic acid chelate. Further, a conductivity-imparting agent such as carbon black or tin oxide may be used for adjusting the conductivity. Further, a release agent such as a fatty acid metal salt or vinylidene fluoride may be used in order to prevent the spent toner from being deposited on the surface of the sleeve or the carrier.

As the base material of the charge-imparting material in the carrier form, all known carriers can be used, and metal such as iron, nickel, aluminum, copper, or alloy or powder or particles of a metal compound containing a metal oxide, Further, glass, ceramic powder or particles of SiC, BaTiO ₂ , SrTiO ₂ or the like is used. Also, those whose surface is treated with resin, or resin powder,
Alternatively, resin powder containing a magnetic material may be used. The average particle size is preferably about 20 to 250 μ.

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

On the other hand, as the toner to be used in combination with the above-described charge-imparting material of the present invention, substantially all of the toners used as conventional toners for developing electrostatic images can be effectively used. That is, both non-magnetic and magnetic toners are used as the toner. More specifically, the toner is a colored fine particle containing a colorant in a binder resin, and if necessary,
You may contain a magnetic powder. Further, these toners may contain a small amount of a charge-imparting substance, for example, a dye, a pigment, or a so-called charge control agent in order to more efficiently impart charge, and a fluidizing agent such as colloidal silica or an oxidizing agent. Abrasives such as cerium, strontium titanate, and silicon carbide, metal stearates, and lubricants such as vinylidene fluoride may be contained. Further, a conductivity-imparting agent such as carbon black or tin oxide may be contained.

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

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

EFFECTS OF THE INVENTION As described above, according to the present invention for imparting a charge to a toner for developing an electrostatic charge image, an electrostatic charge image in which a substituted anthranilic acid chelate having a specific structure as a charge control agent is present on the surface is provided. A charge imparting material for imparting an electric charge to a developing toner is provided. In particular, the substituted anthranilic acid chelate of the present invention has not only excellent charge controllability and stability against heat or moisture absorption, but also the presence thereof by coating or kneading dispersion on the surface of the charge-imparting material. By this, a good charge-imparting material having excellent durability under frictional use with the toner is provided. Therefore, if this charge-giving material is used, the charge-giving agent is mixed only in the toner,
Essential improvements can be obtained for various problems in improving the charging characteristics.

Hereinafter, the present invention will be described in more detail with reference to examples.

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

The iron powder carrier mixed solution was dried to completely remove the solvent and then loosen the light agglomerates 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 a charge control agent.

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

The toner and the carrier were mixed at a weight ratio of 10: 100 to prepare a developer.

The triboelectric charge of this developer was measured by the blow-off method and found to be −7.8 μc / g.

Using this developer, an image was printed on a Canon NP-5000 copier, and the image density did not change even in the durability test of 50,000 sheets, fine line reproducibility was good, and gradation was also good. . There was no fog.

Example 2 Polymethylmethacrylate resin 100 in xylene 1
g was dissolved, and 50 g of the 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 and combined with a toner in the same manner as in Example 1, the triboelectric charge amount of the toner was −8.8 μc / g, and when an image was formed using this, the obtained image was 50,000. Even in the durability test of one sheet, good image density, fine line reproducibility, and gradation, which were completely unchanged from the initial stage, were exhibited and there was no fog.

Example 3 Polymethylmethacrylate resin 100 in xylene 1
g was dissolved, and 50 g of the compound (2) was mixed to prepare a solution. In this solution, Canon NP-400RE
Dipping the developing sleeve (made of stainless steel) for
It was the coat of 0.1mg / cm ² ~0.6mg / cm ² on the sleeve.

This sleeve was set in the original developing machine.

The toner was prepared by a general kneading and pulverizing method according to the following formulation.

Poly (styrene-butylmeth 100 parts acrylate) w = 300,000 Release agent 4 parts (Brand name PE-130: manufactured by Hoechst) Magnetic powder 60 parts (Brand name BL-200: manufactured by Titanium Industry Co., Ltd.) The particle size was adjusted to 1 to 30 μm.

Using this toner, an image was printed on a Canon NP-400RE and a durability test was conducted.

At the endurance of 50,000 sheets, there was no change in the image from the beginning, the fine line reproducibility and gradation were good, and there was no fog.

Also, the surface potential on the sleeve was -38V.
It was confirmed that the toner was completely negatively charged.

Example 4 80 g of a polycarbonate resin was dissolved in xylene 1 and 20 g of the compound (2) was further mixed to prepare a solution.

To this solution, dipping the developing machine developing sleeve blue cartridge Canon of PC-20 (made of aluminum), and the coat 0.1mg / cm ² ~0.5mg / cm ² on the sleeve.

This sleeve was set in the original developing machine.

On the other hand, a toner was prepared by the following formulation.

Poly (styrene-butylmeth 100 parts acrylate) w = 150,000 Release agent 4 parts (trade name PE-130: manufactured by Hoechst) Blue colorant 6 parts (Phthalocyanine pigment) The toner prepared has a particle size of 1 μm to 30 μm. I got it.

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

As a result, there is no change in the image until the toner runs out,
A clear blue image with fine line reproducibility and gradation was obtained. Further, when the surface potential of the toner was measured on the sleeve, -3
It was 7V and was negatively charged.

Examples 5 to 8 The compounds (1) and (2) used in Examples 1 to 4 were respectively described above in order: Compound (3) (Example 5), 〃 (Example 6), Compound (4) ( Example 7), 〃 (Example 8), except that the same as in Examples 1 to 4,
I got a satisfactory result.

The corresponding triboelectric charge amounts and surface potentials were as follows.

Example 5: -7.8 µc / g 〃 6: 11.3 µc / g 〃 7: -43V 〃 8: -29V Examples 9 to 12 The compound (1) or (2) used in Examples 1 to 4 Are described in order above.

Compound (5) (Example 9), 〃 (Example 10), Compound (6) (Example 11), 〃 (Example 12) ,
I got a satisfactory result.

The corresponding triboelectric charge amounts and surface potentials were as follows.

Example 9: -13.1 μc / g 〃 10: -7.3 μc / g 〃 11: -51V 〃 12: -38V Examples 13 to 16 The compound (1) or (2) used in Examples 1 to 4 was used. ) Is replaced with the above-mentioned compound (7) (Example 13), 〃 (Example 14), compound (8) (Example 15), 〃 (Example 16), respectively. Carry out the same procedure as 4
I got a satisfactory result.

The corresponding triboelectric charge amounts and surface potentials were as follows.

Example 13: -7.9 [mu] c / g 〃 14: -8.8 [mu] c / g 〃 15: -24V 〃 16: -35V

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoji Kawagishi 8-1 Sanrahito-cho, Neyagawa-shi, Osaka Orient Chemical Industry Co., Ltd. (56) Reference Japanese Patent Publication No. 3-66667 (JP, B2)

Claims (4)

[Claims] 1. A charge-giving material for developing an electrostatic charge image, which has a chelate compound of a substituted anthranilic acid represented by the following general formula [I] on at least the surface thereof. (In the formula, R ₁ , R ₂ , R ₃ , and R ₄ are the same or different groups selected from hydrogen atom, alkoxy group, aryloxy group, aralkyloxy group, alkylthio group, arylthio group, and aralkylthio group (provided that , Not all hydrogen atoms); and M represents a divalent metal atom.) 2. The charge-imparting material according to claim 1, which is in the form of carrier particles. 3. The charge-giving 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.