JPS61258265A - Charge providing material for developing electrostatic charge image - Google Patents

Abstract

PURPOSE:To prevent deterioration in the performance of a charge providing material by use for a long period by holding specified 1,3,5-triazine on at least the surface of the charge providing material. CONSTITUTION:1,3,5-Triazine represented by the formula (where each of R1, R2 and R3 is H or an electron donative group) is held on at least the surface of a charge providing material. The compound represented by the formula is synthesized by reacting cyanuric chloride with p-toluidine. The compound is generally used in the form of particles of 10-0.01mum average particle size. Polystyrene, polyacrylate or the like can be used as a binding or molding resin, and the resin is used so that the amount of the compound is regulated to 0.5-200pts.wt. per 100pts.wt. resin. When the compound is applied to the surface of the charge providing material, it is preferably applied by 0.01-10mg/cm<2>. Thus, a satisfactory charge providing material having superior durability during use under friction with a toner is obtd.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention provides an improved function for imparting charge to toner used for developing electrostatic images in electrophotography, electrostatic recording, electrostatic printing, etc. Related to materials or members.

[Background of the invention]

Conventionally, 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 No. 24748, etc., but in short, these methods include applying a uniform electrostatic charge to a photoconductive insulating layer and 2 irradiating the insulating layer with a light image. An electrostatic latent image is formed, and then this latent image is developed and visualized using a fine powder called toner in this technology, 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 method 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. As magnetic toners, those containing magnetic particles such as magnetite instead of or in addition to the dyes or pigments described above are used.

In the case of a system using a so-called two-component developer, the above toner is usually mixed with carrier particles such as glass beads and 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 and pigments 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 electrostatic latent image carrier, resulting in contamination of the carrier and the like, as well as contamination of the electrostatic latent image carrier, such as the photoreceptor belt or drum. 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 with the toner binder.

This can be improved by improving the affinity and dispersibility with additives such as dyes and pigments that impart chargeability or charge control agents; however, surface treatment to increase affinity for these additives may reduce chargeability. In many cases, if the toner is mechanically sheared strongly and dispersed finely, the proportion of the additive appearing on the toner surface decreases, and there is a tendency that sufficient chargeability is not imparted. For these reasons, the number of additives that can impart chargeability to toner to a level that is sufficiently satisfactory for practical purposes is extremely limited, and only a small number of them have been put to practical use. In order to obtain a color image, it is preferable that the charge control agent added to the toner be colorless, and in this case, there are almost no practically satisfactory charge control agents.

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. A member (hereinafter collectively referred to as a "charge-imparting material") that comes into contact with the toner during or prior to the development process and imparts the charge necessary for development to the toner, or provides an auxiliary charge to the toner. It has also been proposed to improve the charge imparting characteristics to the toner by using a general term for the materials or members obtained.

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, sources of contamination of carrier particles, photoreceptors, etc. are essentially reduced,
Therefore, repeated development operations do not reduce the charging property or disturb the latent image, and furthermore, the color toner can be easily charged without damaging its tone.

However, charge-imparting materials such as carriers, sleeves, and doctor blades must not only have strong charge-imparting ability, but also be durable and able to withstand friction with toner. For example, carriers must be replaced over a long period of time. In addition, the sleeve is required to have the same degree of durability as the main body of the developing machine.

[Purpose of the invention]

The present invention has been made in order to provide a charge imparting material that solves the above-mentioned problems, and its purpose 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 capable of producing images with excellent fine line reproducibility and #tonality.

A further object of the present invention is to provide a charge imparting material suitable for charging color toners.

[Summary of the invention]

The charge imparting material for developing electrostatic images according to the present invention, which has been made to preferably achieve the above-mentioned various objects, is characterized by the following chemical structural formula: 1,3.5) riazine (in the formula , R, , R2 and R3 represent hydrogen or an electron-donating group and may be the same or different) at least on the surface.

In the above, examples of the electron-donating group include an alkyl group, an alkoxy group, and an amide group.

Typical specific examples of compounds used in the charge-imparting material of the present invention include the following compounds (1) to (8).

(1) (2+”3
Various methods are known for the synthesis of H-N-012M25 triazine. For example, J, A
m, Chem, Soc, 7B, [2, (1954)
;J, Cheya, Sac,, 1947.154HC,
A., 43, 238 (1949); C.A., 45
, 2513. (1951); J, Org, Ghem,
, 17,082 (1952) HCbem, Ber, , 8
7.1885 (t954); 5science.

It has been reported in L. Kuchi, 81 (1955), etc.

For example, the compound example (1) is synthesized by the reaction of cyanuric chloride and p-1 luidine.

The compound generally has an average particle size of 10 to 0.01p, particularly 2 to 0.1p, although it depends on the form of the charge imparting material to be applied.
It is preferable to form the charge imparting material as colored particles.

These compounds can be dissolved or dispersed in a solvent or dispersion medium together with a binder resin if necessary, and then a coating liquid obtained is applied to the base material of the charge imparting material by dipping, spraying,
It can be applied by brushing, etc., or if the base material is in the form of carrier particles, it can be immersed and mixed with the above-mentioned coating liquid and then dried, or it can be coated with a fluidized bed of a direct mixture of this and the above-mentioned compound. The charge-imparting material of the present invention can be obtained by forming a coating layer of the compound on a base material by the method described above. Alternatively, the charge imparting material may be directly melted and kneaded with a binder resin and extruded and laminated onto a base material to obtain a charge imparting material having a coating layer containing the material.Further, these compounds may be contained in a moldable resin. This may be formed into the shape of carrier particles, sleeves, or doctor blades to serve as a charge-imparting material.

As the binder resin or molding resin, common resins can be used, for example.

Polystyrene, polyacrylic acid ester, polymethacrylic acid ester, polyacrylonitrile, rubber resins such as isoprene and butadiene, polyester, polyurethane, polyamide, epoxy resin, rosin, polycarbonate, phenolic resin, chlorinated paraffin, polyethylene.

Derivatives thereof such as polypropylene, silicone resin, Teflon, copolymers thereof, or mixtures thereof can be used. After coating or molding, these resins can be made to have a crosslinked structure, if necessary, to improve the durability of the surface layer of the charge-imparting material.

When a binder resin or a molding resin is used, it is preferable to use the compound in a ratio of 0.5 to 200 parts, particularly 2 to 100 parts, based on 100 parts by weight (the same applies hereinafter).

When coating the surface of the charge imparting material, it is necessary to appropriately control the coating or coating amount of the compound, but
The material is 0. The range is preferably O1 to long/am'', preferably 0.1 to 2 mg/cm''.

In addition to the above-mentioned compounds, ceramic powders such as silica powder, aluminum oxide, cerium oxide, and silicon carbide may also be used as fillers, and conductive agents such as carbon black and tin oxide may be used as fillers. Furthermore, in order to prevent the spent toner from being deposited on the sleeve or carrier surface, # type agents such as fatty acid metal salts, vinylidene fluoride, etc. may be used.

All known carriers can be used as the base material for the charge imparting material in carrier form.

Powder or particles of metals or alloys such as iron, nickel, aluminum, copper, or metal compounds containing metal oxides, as well as glass, 5iQ, BaTiO2, Sr
Ceramic powder or particles such as T+02 are used. Further, examples thereof include those whose surfaces have been treated with resin, resin powder, or resin powder containing magnetic material. Average particle size is 20-25
Approximately 0 JL is suitable.

Furthermore, the base material of the charge imparting material in the form of a sleeve or doctor blade may generally be metals or alloys such as iron, aluminum, stainless steel, or nickel, or non-metallic compounds such as ceramics or plastics, which 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 Aiki invention as described above, 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 can be used. More specifically, the toner is a colored fine particle containing a colorant in a binder resin, and if necessary,
These toners may contain magnetic powder, and may also contain small amounts of charge-imparting substances such as dyes, pigments, or so-called charge control agents in order to impart more effective charge. 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 disdenne fluoride, and may also contain carbon black, tin oxide, etc. It may contain a conductivity imparting agent.

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

〔Effect of the invention〕

As described above, according to the present invention, there is provided a charge imparting material for imparting charge to an electrostatic image developing toner, which has a compound having a specific structure as a charge control agent on its surface. In particular, as shown in the examples below, the compound 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 coated or kneaded onto the surface of a charge-imparting material. When present by dispersion or the like, it provides a good charge-imparting material with excellent durability under hard stones due to friction with toner. Therefore, by using this charge-imparting material, it is possible to obtain a physical improvement over the various problems that occur when the charge-imparting material is mixed only into toner to improve its charging characteristics.

[Embodiments of the invention]

Example 1 100 g of the compound (1) was dissolved and dispersed in 1 u of methyl ethyl ketone (MEK), 1 kg of iron powder carrier (particle size: 250 to 400 mesh) was dispersed therein, and the mixture was stirred for about 30 minutes in a sail mill.

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.

In addition, in order to compare with the product of the present invention, a comparative product carrier was prepared without adding compound (1) in the above procedure.

Separately, a toner was prepared according to the following formulation without adding any charge control agent.

Styrene 100 parts (trade name D-125, manufactured by Esso Chemical Co., Ltd.) Carbon black 6 parts (trade name Thiben 3500, manufactured by Capot Co., Ltd.) The above materials were mixed, crushed, and classified to have a particle size of 1 to 30 lm.

This toner and each of the above carriers were mixed in a weight ratio of 10:100.
was mixed to prepare a developer.

The amount of triboelectric charge of these developers was measured by the blow-off method and was as follows.

Comparative product -21Lc/g When images were produced using a Canon MP-5000 copying machine using these developers, the product of the present invention had a rate of 50.0Lc/g.
Even in a durability test of 00 sheets, there was no change in image density, fine line reproducibility was good, and gradation was also good. There was also no fog. On the other hand, the comparative product showed a change in image density after 3,000 sheets.

Example 2 100% polymethyl methacrylate resin in 1 bottle of xylene
g was dissolved, and 50 g of compound (2) 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 toner in the same manner as in Example 1, the amount of triboelectric charge of the toner was -1''0 G/g, and when this was used to produce an image, the resulting image was Even in a durability test of 50,000 sheets, the image density, fine line reproducibility, and gradation were as good as the initial state, and there was no fog.

Example 3 Polymethyl methacrylate resin 100 in xylene 1i
A solution was prepared by dissolving 50 g of compound (3). A developing sleeve (made of stainless steel) for Canon MP-400RE was dipped in this solution, and the sleeve was coated at a concentration of 0.1 to 0.8 mg/crn'.

In addition, in order to compare with the product of the present invention, a comparative sleeve was prepared without adding compound (3) in the above procedure.

These sleeves were placed in the original developing machine. The toner was prepared according to the following recipe using a general mixing and pulverizing method.

Poly(styrene-butyl methacrylate)) 100 parts Mw = 300,000 Mold release agent (trade name PE-130: manufactured by Hoechst) 4
Part magnetic powder (trade name BL-200: manufactured by Titan Kogyo Co., Ltd.) 80
The particle sizes of the prepared toners were adjusted to 1W to 30W.

Using this toner, an image reproduction durability test was conducted using Canon MP-40ORE. After 50,000 sheets of durability, there was no change in the image from the beginning, fine line reproducibility and gradation were good, and there was no fog.

On the other hand, in the comparison amount, a change in image density occurred after 3,000 sheets.

Further, when the surface potential on the sleeve was measured, it was -25V for the product of the present invention (comparison with Example 3) -7V, confirming that the toner of the product of the present invention was completely negatively charged.

Example 4 A solution was prepared by dissolving 80 g of polycarbonate resin in 1 u of xylene and further mixing 20 g of the compound (0).

Dip the developing sleeve (made of aluminum) of the developing machine of the blue cartridge for Canon PC-2Q into this solution, and add 0.1 to 0,5 I1g/cr onto the sleeve.
I put on an rf coat.

This sleeve was placed in the original developing machine.

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

Poly(styrene-butyl methacrylate) 100 parts Mw
= 150,000 Mold release agent (trade name PE-130: manufactured by Hoechst) 4
Part Blue colorant (phthalocyanine pigment) 6 parts The prepared toner had a particle size of 1 l to 30 particles.

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

As a result, the image does not change until the toner runs out.
A clear blue image with good fine line reproducibility and gradation was obtained. Furthermore, when we measured the surface potential of the toner on the sleeve, we found that -
It was 24V and negatively charged.

Examples 5 to 8 Examples 5 to 8 were carried out in accordance with the procedures of Examples 1 to 4, with the respective compounds used in Examples 1 to 4 being replaced as shown below.

Compound (1)→(5) Example 5 〃(2)→(6)l〆 6 〃(3)→(7) tt 7 〃(4)→(8)〃8 The results are good. The amount of triboelectric charge and surface potential measured correspondingly were as follows.

Example 5-9 Cog //　　　　　　　　-121LC/g // 7 -23 V // 8 -28 V

Claims (4)

[Claims] (1) 1.3.5 triazine represented by the chemical structural formula below ▲ Numerical formulas, chemical formulas, tables, etc. 1. A material for imparting electrostatic charge image development, characterized in that it has on at least the surface a material for electrostatic charge development (which may be different from the above). (2) The charge imparting material for developing an electrostatic image as set forth in claim (1), wherein the charge imparting material is carrier particles. (3) The charge imparting material for developing an electrostatic image as set forth in claim (1), wherein the charge imparting material is a cylindrical sleeve. (4) The charge imparting material for developing an electrostatic image as set forth in claim (1), wherein the charge imparting material is a doctor blade.