JPH0664364B2 - 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] As a conventional electrophotographic method, various methods are described in US 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 the conductive insulator layer and irradiating the insulator layer with a light image, which is then developed by a fine powder called toner in the art. 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. The two-component developing methods include a magnet brush method using an iron powder carrier, a cascade method using a bead carrier, and a fur 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 obtained by finely pulverizing an adhesive resin such as polyethylene having a colorant dispersed therein 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.

However, these additives have to be exposed to the toner surface to some extent in order to impart chargeability. Therefore, these additives fall off from the toner surface due to friction between the toner particles, collision with the carrier, friction with the electrostatic latent image holding member, and contamination of the carrier, electrostatic latent image holding member such as a photoconductor belt. Alternatively, there is a risk of contamination of the drum and the like. As a result, the charging property deteriorates, the deterioration progresses as the number of copies increases, the image density decreases, and fine line reproducibility and fog properties become practical problems.

This is a toner binder and a dye that imparts electrostatic properties,
This can be improved by improving the affinity and dispersibility of the pigment or the charge control agent, but in many cases the surface charge treatment will lower the charge imparting property to increase the affinity of these additives. When the shear is strongly applied and finely dispersed, the proportion of the additive appearing on the toner surface decreases, and the chargeability tends not to be 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.

[Problems to be Solved by the Invention] In view of the above-mentioned circumstances, the present inventors did not adopt a means for imparting charge by using an additive for toner, and did not use a carrier, a sleeve, a doctor blade, or the like for transport regulation or a charging member. We conducted diligent studies to do so.

In the present invention, the charge imparting member is a member capable of imparting an electric charge necessary for developing by contacting the toner or supplementarily imparting it. In this method, the toner does not need to contain a charge-imparting additive, and therefore the above-mentioned problems such as 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 convey or regulate carriers, sleeves, doctor blades, etc., or to make the charging member possess the charge imparting property, the charge imparting substance has a strong charge imparting ability and can be applied, coated or dispersed on the member. Must be a material. Further, the carrier is not used for a long period of time and the sleeve is often used until the developing base becomes unusable. Therefore, the charge imparting 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 charge imparting agent that imparts a suitable negative chargeability 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.

[Means for Solving Problems] The above object can be achieved by the following electrostatic charge image developing member.

That is, the formula (I) or (II) or (III) or (IV)
Or (V) or (VI), (In the formula, R ₁ , R ₂ , R ₃ , R ₄ , and R ₅ are each independently hydrogen, an alkyl group, a cyclic alkyl group, an alkenyl group, an aryl group, an aralkyl group, or an amino group which may have a substituent. Which has a 1,2,3-triazole compound represented by the formula (3) at least on the surface thereof.

The alkyl group is a C _{1 to} C ₂₄ linear or branched alkyl group, and examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group,
Examples thereof include t-butyl group, lauryl group and stearyl group.

The cyclic alkyl group is a cyclopentyl group, a cyclohexyl group, a cyclooctyl group or the like.

Aryl groups include phenyl groups, nitrophenyl groups, thiocarbamoylphenyl groups, tolyl groups, naphthyl groups, 5-
And a methylnaphthyl group.

The aralkyl group is a benzyl group, a 3-methylbenzyl group, a 3-phenylpropyl group or the like. The amino group which may have a substituent is an amino group, a methylamino group,
Examples thereof include a dimethylamino group, an ethylamino group and a diethylamino group.

Specifically, the following compounds can be mentioned.

All of the above compounds can be synthesized by known methods.

The compound may be used as it is as a charge-imparting material by directly dispersing it in a solvent or a dispersion medium, or by dispersing it in a resin.

A ceramic powder such as silica powder, aluminum oxide, cerium oxide, or silicon carbide may be used as a filler. Further, a conductivity-imparting agent such as carbon black or tin oxide may be used for adjusting the conductivity. Further, in order to prevent the spent toner from accumulating on the surface of the sleeve or the carrier, a release agent such as a fatty acid metal salt or vinylidene fluoride may be mixed and used.

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.

When the above charge-imparting compound is mixed and attached to a carrier, the amount attached is 200 g to 2 g per 1 kg of the carrier, preferably 1
00g to 10g is preferable, and the amount of adhesion when it is adhered to a sleeve or the like is 0.01 mg to 10 mg, preferably 0.1 mg to ² mg per 1 cm ^{2 of} effective surface area. 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 charge imparting power and life are saturated and useless.

The carrier to which the compound can be added is not particularly limited, but for example, powders or particles of metals such as iron, nickel, aluminum, copper and alloys thereof.

Powder or particles of a metal compound containing a metal oxide.

Glass, ceramic powder or particles such as SiC, BaTiO ₃ and SrTiO ₃ .

The surface of the above powder or particles is treated with resin or the like.

Resin powder, resin powder containing magnetic material.

And so on.

Further, the sleeve to which the compound can be applied is a metal material such as iron, aluminum, stainless steel, nickel, or an alloy containing these, and ceramics,
A material that can generally be used as a sleeve, such as a non-metal material such as plastics, 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, 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 toner It can be applied to a jumping development method for developing.

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 stearic acid metal salt, and a lubricant such as polyvinylidene fluoride may be contained. Further, a conductivity imparting agent such as carbon black or tin oxide may be contained.

In order to produce the member of the present invention, it is necessary to retain the above compound on the surface of a material or a base material having sufficient contact with the toner before development, specifically, a carrier, a sleeve, a doctor blade or the like. Good. 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 tank and adhering it to the surface of the carrier core by 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 it into a carrier, a sleeve, a doctor blade and the like.

[Examples] The present invention will be described in more detail with reference to the following examples.

Example 1 100 g of 4,5-dimethyl-1-dimethylamino-1H-1,2,3-triazole (1) was dissolved and dispersed in methyl ethyl ketone 1 and 1 kg of iron powder carrier (particle size: 250 to 400 mesh)
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 Cabot Corporation) 6 parts The above toner materials are kneaded, crushed, classified, and have a particle size of 1 to 1.
Aligned to 30 μm.

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

When the tribo of this developer was measured by the blow-off method, it was -5.9 μc / g. Using this developer, an image was printed with a Canon NP-5000 copier.
Even in the durability test of the sheets, fine line reproducibility was good, gradation was also good, and there was no fog at all.

Example 2 Polymethylmethacrylate resin 120 in xylene 1
g was dissolved, and 50 g of 4,5-n-heptyl-2-diethylamino-2H-1,2,3-triazole (2) was mixed with this. This was treated into an iron powder carrier of 1 kg 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, a toner exactly the same 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 -5.4 μc / g.

Using this developer, an image was printed on a Canon NP-5000 copier, and it showed good image density, fine line reproducibility, and gradation even at the endurance test of 50,000 sheets, even with fog. I couldn't do it.

Comparative Example 4,5-n-heptyl-2-diethylamino-2H-1,2,3-
Nitron instead of 50 g of triazole (2) A carrier was prepared as in Example 2 except that 50 g was used. The toner was mixed with the obtained carrier in the same manner as in Example 2 to adjust the developer, and the triboelectric charge amount of the toner was measured in the same manner as in Example 2 to obtain -9.5 μC.
/ G, but when the triboelectric charge amount of the toner was measured in a high temperature and high humidity environment of a temperature of 35 ° C. and a humidity of 90 RH, it was −5 μc
/ G significantly decreased.

On the other hand, the frictional charge of the toner of the developer having the carrier of Example 2 was -4.5 μC / g when measured in a high temperature and high humidity environment where the temperature was 35 ° C. and the humidity was 90% RH. The fluctuation was small compared with the lower triboelectric charge amount (-5.4 μC / g).

Example 3 Polymethylmethacrylate resin 100 in xylene 1
g was dissolved and 4,5-bis (diethylamino) -3H
A solution was prepared by mixing 50 g of 1,2,3-triazole (3).

Dip a development sleeve (made of stainless steel) for Canon NP-400RE into this solution and apply compound example (3) to the sleeve surface.
The amount of deposition to obtain a member of the coated invention as will ^{0.1mg / cm 2 ~0.6mg / cm 2} .

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 and the like.

Poly (styrene-butyl methacrylate) w = 300,00
0 100 parts Release agent (trade name PE-130: Hoechst) 4 parts Magnetic powder (trade name BL-200: Titanium Industry Co., Ltd.) 60 parts Using this toner, image development with Canon NP-400RE and durability I did a test. 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.

After the endurance test, the surface potential of the toner on the sleeve was measured and found to be -29 V, which confirmed that the toner was completely negatively charged.

Example 4 80 g of a polycarbonate resin was dissolved in xylene 1,
Further, a solution was prepared by mixing 20 g of 1H-1,2,3- (5-methyl-1-dimethylamino) benzotriazole (4).

Dipping the developing sleeve (made of aluminum) of the developing machine of the Canon PC-20 blue cartridge into this solution,
The amount of Compound Example (4) deposited on the sleeve surface is 0.1 mg / cm ^{2 to} 0.5 m
A member of the present invention was obtained by coating as g / cm ² . This sleeve was set in the original developing machine.

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

Poly (styrene-butyl methacrylate) w = 150,00
0 100 parts Release agent (trade name PE-130: manufactured by Hoechst) 4 parts Blue colorant (phthalocyanine pigment) 6
By using this toner and a developing machine equipped with the above sleeve, the PC-20 was modified to enable reversal development, and a durable image was produced.

The toner was charged to 100 g, and the test was conducted until the toner ran out. However, 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.

[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, and fine line reproducibility and gradation are obtained. Good and less fogging. The durability test is also excellent.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Katsuhiko Tanaka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-59-78365 (JP, A) JP-A-59 -177565 (JP, A) JP-A-59-200253 (JP, A) "Coloring material" Vol. 50 No. 9 (1977) 517-519, 522

Claims (2)

[Claims] 1. A formula (I) or (II) or (III) or (I
V) or (V) or (VI), (In the formula, R ₁ , R ₂ , R ₃ , R ₄ , and R ₅ are each independently hydrogen, an alkyl group, a cyclic alkyl group, an alkenyl group, an aryl group, an aralkyl group, or an amino group which may have a substituent. And a 1,2,3-triazole-based compound represented by 2. The electrostatic charge image developing charge imparting member according to claim 1, which is a member for imparting a negative triboelectric charge to the toner.