JPS61122661A - Triboelectrifying material for developing electrostatic charge image - Google Patents

Abstract

PURPOSE:To give a toner proper negative triboelectrifiability by coating the surface of a carrier or the like with a metal complex of optionally substd. picolinic acid deriv. to form a material for triboelectrifying the electrostatic charge image developing toner. CONSTITUTION:The complex of picolinic acid deriv. optionally substd. by at least one of Cl, nitro, methyl, ethyl, or the like represented by formula I, II, or the like of a metal, such as Fe, Cr, Mg, Cd, Co, Pt, or Ag, is synthesized. The surface of the carrier, sleeve, or doctor blade is coated with said metal complex to form the material for electrifying the toner. To embody this process for the carrier, the surfaces of the carrier cores are dipped in a vessel contg. a soln. dissolving or dispersing said complex, or sprayed with said soln., or treated by the fluidized bed process to attach it to the surfaces of the cores.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a member that charges toner for developing electrostatic images in electrophotography, electrostatic recording, electrostatic printing, and the like.

[Prior Art] Various conventional electrophotographic methods have been described in U.S. Pat. , they essentially provide a uniform electrostatic charge on a photoconductive insulator layer, form an electrostatic latent image by irradiating the insulator layer with a light image, and then transfer the latent image to a toner using the technique. The image is developed and visualized using a fine powder called .D., and if necessary, the powder image is transferred to paper or the like, and then fixed using heat, pressure, or solvent vapor.

Development methods applicable to these electrophotographic methods include:
Broadly speaking, there are dry development methods and wet development methods. The former method is roughly divided into methods using a two-component developer and methods using a -component developer.

Two-component developing methods include a magnetic brush method using an iron powder carrier, a cascade method using a bead gear carrier, a fur brush method using fur, etc., depending on the type of carrier for conveying the toner.

In addition, those belonging to the -component type 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.

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 coloring agent in an adhesive resin such as polyethylene and pulverizing the particles to about 1 to 30 liters are used as toner. As the magnetic toner, one containing magnetic particles such as magnetite is used.

In the case of a system using a so-called two-component developer, 5
The toner is usually mixed with carrier particles such as glass beads or iron powder.

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

In order to make the toner retain an electric charge, it is also possible to use the triboelectricity of the resin that is a component of the toner, but with this method, the toner's chargeability is small, so the images obtained by development are likely to fog and become unclear. becomes. Therefore,
In order to impart desired triboelectric charging properties to the toner, dyes, pigments, and even charge control agents that impart electrostatic properties are added to the toner.

However, these additives must be present on the surface of the toner to some extent in order to impart charging properties. Therefore, the toner may be damaged due to friction between the toners, collision with the carrier, friction with the electrostatic latent image carrier, etc. There is a risk that these additives may fall off from the surface, resulting in contamination of the carrier, etc., and contamination of the electrostatic latent image carrier, such as the photoreceptor belt or drum. As a result, the charging property deteriorates, and as the number of images is increased, the deterioration progresses and the density of one image increases.
, decreases, and problems such as fine line reproducibility and capriality become a problem in practice.

This can be improved by improving the affinity and dispersibility of the toner binder and the dye, pigment, or charge control agent that imparts chargeability, but if surface treatment is performed to increase the affinity of these additives, In many cases, the charge imparting properties are reduced, and if mechanical shear is strongly applied and finely dispersed, the proportion of additives that appear on the toner surface decreases.
There is a tendency that sufficient chargeability is not imparted. For these reasons, the number of charge-imparting additives that are sufficiently satisfactory for practical use is extremely limited, and only a small number of them have been put into practical use, especially in order to cope with the increasing demand for not only black and white images but also color images in the future. For this reason, it is preferable that the additive added to the toner be colorless, and there are currently almost no additives that have been put to practical use that meet this requirement.

[Problems to be Solved by the Invention] In view of the above-mentioned circumstances, the present inventors did not adopt a method of imparting a charge using toner additives, but instead used means for controlling conveyance such as carriers, sleeves, doctor blades, etc. or using charging members. We conducted intensive studies to consider this.

In the present invention, the charge imparting member is a member that contacts the toner and imparts or auxiliary charges necessary for development. In this method, it is not necessary to contain almost any charge-imparting additive in the toner, so the above-mentioned problems such as contamination of the carrier, photoreceptor, etc. do not occur, and the chargeability decreases during image formation and the latent image will no longer be disturbed. Furthermore, color toner can be easily charged.

However, in order to control the transport of carriers, sleeves, doctor blades, etc., or to make charging members possess charge-imparting properties, charge-imparting substances must be materials that have a strong charge-imparting ability and can be applied, coated, or dispersed onto members. Furthermore, since the carrier does not need to be replaced for a long period of time, and the sleeve is often used until the current *a main body becomes unusable, the charge imparting member must be able to withstand long-term use.

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

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

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

A further object of the present invention is to provide a charge-imparting member capable of producing images with excellent fine line reproducibility and gradation.

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

Means for Solving Problem E] That is, the present invention provides a charge imparting device for developing an electrostatic image, characterized in that it has a gold m-complex of picolinic acid or a picolinic acid rust conductor having one or more substituents on at least the surface thereof. It is a member.

The substituents in the metal complex of the present invention are a filler S atom, a nitro group, a methyl group, and an ethyl group, and the metals constituting the complex are (:r, F@, Mg, Cd, Co.

To Pt, Customer A.

Typical specific examples of compounds used in the charge-imparting member of the present invention include the following.

[Compound example]

These compounds are extremely stable and can be synthesized by known methods. Generally, when picolinic acid and alkali are added to an aqueous solution of each metal salt and heated, precipitation occurs.

It can be obtained by purifying, drying, and pulverizing this.

The metal salt aqueous solution mentioned above is an organic compound such as nitric acid, sulfuric acid, chloride, acetic acid, etc.
An aqueous solution of a metal salt of an inorganic acid with relatively high solubility in water is usually preferably used.

The above compound may be used as a charge imparting material by being dispersed in an i-agent or a dispersion medium as it is, or may be used by being dispersed in a resin.

In addition, ceramic powder such as silica powder, aluminum oxide, cerium oxide, and silicon carbide may be used as a filler, and conductivity imparting agents such as carbon black and e# tin may be used to adjust the conductivity. Furthermore, in order to prevent the accumulation of spent toner on the sleeve or carrier surface, a release agent such as a fat-resistant metal salt, vinylidene fluoride, etc. may be mixed and used.

In addition, common resins can be used as the dispersing resin. For example, polystyrene, polyacrylic acid ester, polymethacrylic acid ester, polyacrylonitrile,
Rubber resins such as isoprene and butadiene, polyesters, polyurethanes, polyamides, epoxy resins, rosins, polycarbonates, phenolic resins, chlorinated paraffins, polyethylene, polypropylene, silicone resins, Teflon and their derivatives, copolymers, and mixtures are used. It is possible.

When the charge-imparting compound is mixed and deposited on a carrier, the amount of the charge-imparting compound is preferably 20 g to 5 g per kg of carrier, and when it is deposited on a sleeve etc., the amount of the charge-imparting compound is 0.01 g per 1 cm2 of effective surface area. ■g
N10■8, preferably 0.11g to 2mg is good; if it is less than the above range, the charging force and lifespan will deteriorate6
is not sufficient, and even if it is used beyond the above range, the effects such as charge imparting power and lifespan will be saturated and it will be wasteful.

The carrier to which the compound can be added is not particularly limited, but includes, for example, powders or particles of metals such as iron, nickel, aluminum, and copper and alloys thereof, powders or particles of metal compounds containing metal oxides, glass, and SiC. ,Ba
Examples include ceramic powders or particles such as TiO3 and 5rTi03, the surfaces of the above powders or particles treated with resin, resin powders, and resin powders containing magnetic substances.

Furthermore, sleeves to which the above compound can be applied include metal materials such as metals such as iron, aluminum, stainless steel, and nickel, or alloys containing these metals, and non-metallic materials such as ceramics and plastics, which can generally be used as sleeves. Any material may be used.

Furthermore, the toner used when using the member of the present invention can be either non-magnetic or magnetic toner, regardless of whether it is a two-component development method or a -component development method.

It can be applied to all methods in which the toner is charged and developed.

For example, magnetic brush development method, cascade development method, fur brush development method, so-called microtoning development method using magnetic material-containing resin powder as a carrier, development method using resin powder as a carrier, so-called jumping development method, or non-magnetic toner. It can be applied to jumping development methods, etc. that develop images.

These toners provide more efficient charging, so
A small amount of a charge-imparting substance such as a dye, a pigment, or a so-called charge control agent may also be included as long as it does not adversely affect the practice of the present invention.

It may contain a fluidizing agent such as colloidal silica, an abrasive agent such as cerium oxide, strontium titanate, and silicon carbide, a lubricant such as metal stearate, and vinylidene fluoride, and a lubricant such as carbon black and tin oxide. It may contain a conductivity imparting agent.

In order to manufacture the member of the present invention, it is preferable to hold the compound on the surface of a material or equipment that has a sufficient opportunity to come into contact with the toner before the development stage, specifically, a carrier, a sleeve, a doctor blade, etc. That is, in carrier treatment, a solution in which the above compound is dissolved or dispersed is soaked in a tank, sprayed, or using a fluidized bed.
Ordinary methods such as attaching it to the surface of the carrier core are employed.

In addition, when coating a sleeve or the like, methods such as dipping, spraying, and brushing are used using the same solution.

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

Example 1 100 g of compound example (1) in 1 liter of methyl ethyl ketone
Dissolve and disperse, and add iron powder carrier (particle size: 25G to 4
0Qsesh) I Kg was dispersed and stirred and mixed in a ball mill for about 30 minutes. After drying this iron powder carrier mixture to completely remove the solvent, the agglomeration was slightly loosened to obtain an electrostatic charge developing member of the present invention.

Separately, toners were prepared with the following formulation using conventional materials and methods. No charge imparting substance was contained (the following parts indicate parts by weight).

Polystyrene (trade name D-125: Esso Chemical) 10
0 parts Carbon black (trade name: Raven 3500, manufactured by Gear Pot Co., Ltd.) 8 parts The above toner material was mixed, crushed, and classified to have a particle size of 1 to 30 μs. The weight ratio of this toner and the carrier is lO:l
It was mixed with GG to prepare a developer. When the tripometry of this developer was measured by the blow-off method, it was -8.84 c/g. Using this developer, Canon MP-5000
When the image was produced using a copying machine, there was no change in image density even after a 50,000-sheet durability test, with good fine line reproducibility and good gradation.

There were no capri either.

Example 2 100 g of polymethyl methacrylate resin was dissolved in xylene lt, and 55 g of compound example (2) was added thereto.
0g was mixed. This was processed into 1 kg of 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, a toner exactly the same as in Example 1 was prepared, and the toner and carrier were mixed in the same weight ratio as in Example 1 to prepare a developer.

When the triboelectricity of this developer was measured by the blow-off method, it was -1Q, 9% c/g. When this developer was used to produce an image on a Canon NP-5000 copying machine, it showed good image density, m-recording reproducibility, and gradation, which were exactly the same as the initial image even in a 50,000-sheet durability test. No fogging was observed either.

Example 3 Polymethyl methacrylate resin 10 in xylene lt
A solution was prepared by dissolving 0 g of the compound and mixing it with 50 g of Compound Example (3). Add Canon NP-400RJ to this solution.
A developing sleeve (made of stainless steel) for E was dipped, and the amount of compound example (3) attached to the sleeve surface was 0.1 mg.
/c+wz~0.8mg/am2 coat
, and a member of the present invention was obtained. This sleeve was placed in the original developing machine.

The toner was made into a particle size of 1 l to 30 p according to the following formulation through general steps such as cross-mixing, crushing, and classification.

Poly(styrene-butyl methacrylate) Rufu 300.
000 100 room type agent (
Product name: PH-130: manufactured by Hoechst Co., Ltd.) 4 parts Magnetic powder (product name: BL-200: manufactured by Titanium Kogyo Co., Ltd.) 60 parts Using this toner, an image printing durability test was conducted using Canon's NP (OGRE). 50. After 1,000 sheets of durability, there was little change in the image from the beginning, fine line reproducibility and gradation were good, and there was no fogging.

Furthermore, when the surface potential of the toner on the sleeve was measured after the end of the durability test, it was found to be -33V, confirming that the toner was completely negatively charged.

Example 4 A solution was prepared by dissolving 80 g of polycarbonate resin in xylene 11 and further mixing 20 g of Compound Example (4). A developing sleeve (made of aluminum) of a developing machine for a blue cartridge for Canon PC-20 was dipped in this solution, and a compound example (0.
A member of the present invention was obtained by coating the material at a concentration of 1 mg/am" to 0-5 mg/c+++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 l~30.
Poly(styrene-butyl methacrylate) VkI 15 aligned with IL
0,000 Toi part separation part side type agent Product name PE-130: Manufactured by Hoechst) 4 parts Blue colorant (phthalocyanine pigment) 6 parts Using this toner, using a developing machine equipped with the above sleeve, PC-20
We modified it to enable reversal development and produced durable images.

100 g of toner was filled and a test was conducted until the toner ran out, but there was no change in one image, and a clear blue image with good fine line reproducibility and gradation was obtained. Furthermore, when the surface potential of the toner on the sleeve was measured, it was -41 V, confirming the charge imparting effect.

Examples 5 to 10 Compound examples (5) to (10) were obtained in the same manner as in Examples 1 to 4 to obtain electrostatic charge developing members of the present invention, and their performance was evaluated in the same manner as in Examples 1 to 4. went.

Regarding the solvents, dispersants, component configurations, performance test methods, and performance evaluations used for each compound,
Table 1 includes the cases of Examples 1 to 4. As shown in the performance evaluation column, all the electrostatic charge developing members obtained using each compound exhibited good performance.

The methods are abbreviated as shown in the table.

MEK・・・・・・Methyl ethyl ketone PMMA
...Polymethyl methacrylate resin PS...
・・・・・・・・・Polystyrene (product name D-12
5: Esso Chemical) PSB 300,000...Poly(styrene-butyl methacrylate L/-)) Tl2O3,000 PSB 150,000...Poly(styrene-butyl methacrylate)
Mw15G, 000PC...Polycarbonate resin CB...Carbon black (product name Raven 3500: manufactured by Gearbot) Mold release agent and magnetic powder are each The product with the trade name described in Example 3 was used.

Image density: Good fine line reproducibility and two-tone gradation were indicated as O.

Table 1 (continued) Performance evaluation [■] Image output test [Effects of the invention] By using the charge imparting member according to the present invention, it is possible to obtain images by developing electrostatic images in electrophotography, electrostatic recording, electrostatic printing, etc. Images have very little change in density over a long period of time, have good fine line reproducibility and gradation, have little fog, and can be effectively used for color development, producing extremely clear images.

Claims (2)

[Claims] (1) A charge-imparting member for developing an electrostatic image, characterized in that it has a metal complex of picolinic acid or a picolinic acid derivative having one or more substituents on at least its surface. (2) The compound according to claim 1 is a carrier,
The charging member for developing an electrostatic image according to claim 1, which is coated on a sleeve or a doctor blade.