JPH0638170B2 - Charging member for electrostatic image development - Google Patents

Description

TECHNICAL FIELD The present invention relates to a member for charging a toner for developing an electrostatic charge image in electrophotography, electrostatic recording, electrostatic printing and the like.

[Prior Art] Conventional electrophotographic methods are described in various methods such as U.S. Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910 and Japanese Patent Publication No. 43-24748. An electrostatic latent image is formed by applying a uniform electrostatic charge on a conductive insulator layer and irradiating the insulator layer with a light image, which is then developed by fine powders known in the art as toner. After visualizing and transferring the powder image to paper or the like as necessary, fixing is performed by heating, pressurizing, or solvent vapor.

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, and a far brush method using a fur, depending on the type of carrier that carries the toner.

Further, the one-component developing method includes a powder cloud method in which toner particles are sprayed, and 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 (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 an adhesive resin such as polystyrene and finely pulverized to about 1 to 30 μm are used as a toner. A magnetic toner 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 used by being mixed with carrier particles such as glass beads and iron powder.

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

To retain the electric charge in the toner, it is possible to utilize 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. Becomes Therefore,
In order to impart a desired triboelectric charging property to a toner, a dye, a pigment, or a charge control agent that imparts the charging property is added.

[Problems to be Solved by the Invention] However, these additives must be exposed to some extent on the toner surface in order to impart chargeability. Therefore, these additives fall off from the toner surface due to friction between toners, collision with a carrier, friction with an electrostatic latent image carrier, contamination of the carrier, electrostatic latent image carrier such as a photoconductor belt. Or contamination of the drum etc. occurs. As a result, the charging property deteriorates, the deterioration progresses as the number of durable sheets increases, the image density decreases, and fine line reproducibility,
Fog properties become a problem in practical use.

This can be improved by improving the affinity and dispersibility of the toner binder and the dye, pigment or charge control agent that imparts the charging property, but if the surface treatment is performed to increase the affinity of these additives. In many cases, the charge imparting property is lowered, and when mechanically strongly applying fine shear force to finely disperse the toner, the proportion of the additive appearing on the toner surface decreases,
There is a tendency that the chargeability is not sufficiently imparted. For these reasons, the charge imparting additives that are sufficiently satisfactory in practice are extremely limited, and only a few have been put into practical use. In particular, in order to cope with an increase in demand for not only black and white images but also color images in the future, it is preferable that the additive to be added to the toner is colorless, and at present, there are few practical additives that meet this condition.

[Means for Solving Problems] In view of the above-mentioned circumstances, the present inventors did not adopt a means of imparting charge by using an additive of toner, and instead of carrying control such as a carrier, sleeve, doctor blade, or charging member. We conducted diligent studies to do so.

The charge imparting member is a member capable of being in contact with the toner and imparting an electric charge necessary for development, or an auxiliary charge. In this method, the toner hardly needs to contain the additive for imparting charge, so that the above-mentioned problems, for example, contamination of the carrier and the photoconductor do not occur, the chargeability is lowered during image formation, and the latent image is not formed. Will not disturb. Further, the color toner can be easily charged.

However, in order to regulate the transportation of carriers, sleeves, doctor blades, etc., or to make the charging member possess the charge imparting property, a material having a strong charge imparting ability and capable of being applied, coated or dispersed on the member must be used.
Further, since the carrier is often used without replacement for a long period of time and the sleeve is often used until the main body of the developing machine becomes unusable, the charging member must be durable for a long period of time.

An object of the present invention is to provide a charging member that solves the above-mentioned problems.

A further object of the present invention is to provide a charging member that imparts a proper negative charging property to the toner.

A further object of the present invention is to provide a charge imparting member that does not deteriorate in performance after long-term use.

A further object of the present invention is to provide a charging member that can obtain an image with excellent fine line reproducibility and gradation.

A further object of the present invention is to provide a charging member suitable for colorization.

That is, the present invention is (a) the following general formula (However, n represents an integer of 4 or 5, R ₁ and R ₂ represent an alkyl, aryl, or aralkyl group or a derivative having these as a basic skeleton, and A ⁻ represents an anion.) A ring compound and / or (b) a compound in which the heterocyclic compound represented by the above general formula further has a substituent on the carbon constituting the heterocycle, wherein the substituent is alkyl or aryl Or an aralkyl group, or a heterocyclic compound which is a derivative having these as a basic skeleton, on at least the surface thereof, to a charging member for electrostatic image development.

R ₁ and R ₂ are usually a C _{1 to} C ₂₀ alkyl group, a C _{6 to} C ₁₂ aryl group, and a C _{7 to} C ₂₀ aralkyl group, and may be the same or different. The aryl group and aralkyl group may be a single ring or a condensed ring. As the derivatives thereof, halogen-substituted compounds, amino groups, nitro groups, acyl groups,
A cyano group, an aryl group, an alkoxy group substitution product, etc. are selected.

Substituents in the heterocycle typically alkyl of _{C 1 ~C 20, C 6 ~C} 12
1 to 5 aryl and C _{7 to} C ₂₀ aralkyl groups, which may be the same or different. As the derivative thereof, a halogen-substituted product, an amino group, a nitro group, an acyl group, a cyano group, an aryl group, an alkoxy group-substituted product and the like are selected.

A ⁻ is, for example, Cl ⁻ , Br ⁻ , I ⁻ , NO ₃ ⁻ , Or Indicates.

The following are typical specific examples of the compound used in the charging member of the present invention.

[Compound example]

(1) (2) (3) (Four) (Five) (6) (7) (8) (9) (Ten) (11) (12) (13) (14) These compounds are synthesized by known methods.

For example, piperidine (II) or pyrrolidine (III)
(All are commercially available from Tokyo Chemical Industry Co., Ltd.)
It is synthesized by reacting an alkyl halide or a dialkyl sulfate.

[Example of reaction] The compound may be used as it is as a charge-imparting material by being dispersed in a solvent or a dispersion medium as it is, or may be used by being dispersed in a resin.

In addition, silica powder, ceramic powder such as aluminum oxide, cerium oxide, and silicon carbide may be used as a filler. Further, a conductivity imparting agent such as carbon black or tin oxide may be used for controlling the conductivity. Further, a release agent such as a fatty acid metal salt or vinylidene poride may be mixed and used in order to prevent accumulation of the spent toner on the surface of the surviv or carrier.

Moreover, as the resin for dispersion, a general resin 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, phenol resin, chlorinated paraffin, polyethylene, polypropylene, Silicone resin, Teflon and their derivatives, copolymers,
Mixtures can be used.

Furthermore, the sleeve to which the compound can be applied is a metal material such as a metal such as iron, aluminum, stainless steel, nickel, or an alloy containing the same, and ceramics,
A material that can generally be used as a sleeve, such as a non-metallic material such as plastic, may be used.

Further, the toner used when using the member of the present invention is effective for both non-magnetic and magnetic toners, and is applicable to all systems in which toner is charged and developed regardless of the two-component developing method or the one-component developing method. Applicable.

For example, a magnetic brush developing method, a cascade developing method, a far brush developing method, a so-called microtoning developing method using a magnetic substance-containing resin powder as a carrier, or a developing method using a resin powder as a carrier, a so-called jumping developing method, or a non-magnetic toner is used. It is applicable to a jumping developing method for developing.

When the charge-imparting compound is mixed and adhered to the carrier, the adhesion amount is 1 g to 100 g, preferably 5 to 20 g per 1 kg of the carrier, and the adhesion amount when adhering to the sleeve is 0.01 mg to 1 cm ² of the effective surface area. 10 mg, preferably 0.1 mg to 2 mg is good. If it is less than the above range, the charge imparting power and life are insufficient, and even if it is used beyond the above range, the effects such as the charge imparting power and life are saturated and useless.

The carrier to which the compound can be applied is not particularly limited, but for example, powders or particles of metals such as iron, nickel, aluminum and copper and alloys thereof, powders or particles of metal compounds including metal oxides, glass, SiC. ， BaTi
Ceramics powder or particles, such as O _3, SrTiO _3, the surface of the powder or particulate those treated with resin or the like, resin powder, and the like resin powder containing a magnetic material.

These toners provide more efficient charging,
A small amount of a charge imparting substance, for example, a dye, a pigment, or a so-called charge control agent may be contained as long as it does not adversely affect the practice of the present invention, and a fluidizing agent such as colloidal silica, cerium oxide, strontium titanate. An abrasive such as silicon carbide, a metal salt of stearic acid, and a lubricant such as vinylidene fluoride may be contained. Further, a conductivity imparting agent such as carbon black or tin oxide may be contained.

In order to manufacture the member of the present invention, the compound may be held on the surface of a material or equipment, such as a carrier, a sleeve or a doctor blade, which has a chance to sufficiently contact with the toner before development. That is, in the carrier treatment, a usual method such as immersing a solution in which the above compound is dissolved or dispersed in a bath and adhering it to the carrier core surface using a spray or a fluidized bed is adopted.

When coating on a sleeve or the like, the same solution is used, and a method such as a dipping method, a spray method, or a brush coating method can be used.

Further, the member of the present invention can be manufactured by incorporating the above compound into a moldable resin by a known method, and then molding into a carrier, a sleeve, a doctor blade and the like.

[Examples] Example 1 100 g of Compound Example (1) was dissolved and dispersed in 1 liter of methyl ethyl ketone, and 1 kg of iron powder carrier (particle size: 250 to 400 mesh) was added thereto.
Were dispersed and mixed by stirring in a ball mill for about 30 minutes. The iron powder carrier mixed solution was dried to completely remove the solvent, and then lightly agglomerated to obtain an electrostatic charge developing member of the present invention.

Separately, a toner was prepared according to the following formulation by a conventional material and method. The charge-imparting substance was not included (the following parts indicate parts by weight).

Polystyrene (trade name D-125: manufactured by Esso Kagaku) 100 parts Carbon black (trade name Raven 3500: manufactured by KYABOT) 6 parts The above toner materials are kneaded, crushed and classified to a particle size of 1 to 30.
Aligned to μm. This toner and the carrier are in a weight ratio.
The mixture was mixed at 10: 100 to obtain a developer. When the tribo of this developer was measured by the blow-off method, it was -10.3 μc / g. Using this developer, an image was printed on a Canon NP-5000 copier, and it showed good fine line reproducibility, good gradation, and no fog even in the durability test of 50,000 sheets.

Example 2 100 g of polymethylmethacrylate resin in 1 l of xylene
Was dissolved, and 50 g of the compound (2) was mixed therein. This was treated into 1 kg of an iron powder carrier in the same manner as in Example 1 to obtain a carrier having a charge imparting effect, which is a member of the present invention. Separately, the same toner as in Example 1 was prepared, and the toner and the carrier were mixed in the same weight ratio as in Example 1 to obtain a developer. When the tribo of this developer was measured by the blow-off method, it was -9.4 μc / g. An image was printed using a Canon NP-5000 copier with this developer.
Even in the endurance test of 000 sheets, good fine line reproducibility and gradation were obtained, which were not changed from the initial stage, and no fog was observed.

Example 3 100 g of polymethylmethacrylate resin in 1 l of xylene
Was dissolved and 50 g of the compound (3) was mixed to prepare a solution. The solution was dipped developing sleeve (stainless steel) for Canon NP-400RE, the present invention adhesion amount of compound examples (3) to the sleeve surface was coated as will 0.1mg / cm ² ~0.6mg / cm ² The member was obtained. This sleeve was set in the original developing machine.

The toner was made to have a particle size of 1 μm to 30 μm according to the following formulation through general kneading, pulverizing, classifying, etc.

Poly (styrene-butylmethacrylate) _W = 300,000 100 Release agent (trade name PE-130: Hoechst) 4 parts Magnetic powder (trade name BL-200: Titanium Industry Co., Ltd.) 60 parts Image durability test was performed with NP-400RE. After 50,000 sheets, the image did not change much from the beginning, the fine line reproducibility and gradation were good, and there was no fog.

Further, when the surface potential of the toner on the sleeve was measured after the endurance test, it was -27 V, and it was confirmed that the toner was completely negatively charged.

Example 4 80 g of a polycarbonate resin was dissolved in 1 liter of xylene,
Further, a solution was prepared by mixing 20 g of the compound example (4). Dip a developing sleeve (made of aluminum) of a Canon PC-20 blue cartridge storage machine into this solution,
The amount of Compound Example (4) deposited on the sleeve surface is 0.1 mg / cm ^{2 to} 0.5.
The material of the present invention was obtained by coating as much as mg / cm ² . This sleeve was set in the original developing machine.

On the other hand, the toner is prepared according to the following formulation, and the particle size is 1 μ to 30 μ
I prepared it.

Poly (styrene-butylmethacrylate) _W = 150,000 100 Release agent (trade name PE-130: Hoechst) 4 parts Blue colorant (phthalocyanine pigment)
6 parts Using this toner, a developing machine equipped with the above sleeve was used to modify the PC-20 so that reversal development was possible, and a durable image was printed.

The toner was charged to 190 g and tested until the toner ran out, but there was no change in the image and a clear blue image with good fine line reproducibility and gradation was obtained. Further, the surface potential of the toner on the sleeve was measured and found to be -31 V, confirming the charging effect.

Examples 5-8 The experiment was repeated exactly as in Example 1 except that the compound was replaced.

[Advantages of the Invention] By using the charging member according to the present invention, an image obtained by developing an electrostatic image in electrophotography, electrostatic recording, electrostatic printing, or the like has very little change in density over a long period of time, and fine line reproducibility and Good gradation and less fog. Further, it can be effectively used for color development, and an extremely clear image can be obtained.

Claims (2)

[Claims] 1. The following general formula: (However, n represents an integer of 4 or 5, R ₁ and R ₂ represent an alkyl, aryl, or aralkyl group or a derivative having these as a basic skeleton, and A ⁻ represents an anion.) A ring compound and / or (b) a compound in which the heterocyclic compound represented by the above general formula further has a substituent on the carbon constituting the heterocycle, wherein the substituent is alkyl or aryl , Or an aralkyl group, or a heterocyclic compound which is a derivative having these as a basic skeleton, on at least the surface thereof. 2. The electrostatic charge image developing charge imparting member according to claim 1, wherein the heterocyclic compound (a) and / or (b) is coated on a carrier, a sleeve or a doctor blade.