JPS635359A - Electric charge imparting material for developing electrostatic image - Google Patents

Abstract

PURPOSE:To obtain the titled material having an improved electrostatic charge characteristics of a toner by incorporating a diorganotin phosphate to at least the surface of the titled material. CONSTITUTION:The carrier type electric charge imparting material is obtd. by dissolving the diorganotin phosphate in a solvent, followed by dispersing it, and by dispersing the carrier of iron powders to the obtd. dispersion, followed by agitating it in a ball mill, and subsequently, drying the mixture until the solvent is completely removed, and by disassembling the obtd. weak cohesive material. Thus, the titled material which does not decrease the electrostatic charge and does not disorder a latent image by repeating a development, is obtd. The titled material facilitates the electrostatic charge, without injuring a color tone of the color toner.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention improves the function of imparting charge to toner used for developing electrostatic images in electrophotography, electrostatic recording, electrostatic printing, etc. The present invention relates to a material or member having a fixed shape, that is, a charge imparting material (herein, the word "material" is used to include granular materials in addition to members having a regular shape).

[Prior Art] Conventionally, various electrophotographic methods have been described in US Pat. However, in short, they change a uniform electrostatic charge to the photoconductive insulating layer L, form an electrostatic latent image by irradiating the insulating layer with a light image, and then transfer the latent image to the photoconductive layer L. In this technology, a fine powder called toner is used to develop and visualize the image, and if necessary, the powder image is transferred to paper or the like, and then fixed by heat, pressure, or solvent vapor.

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 one-component developer.

The two-component developing method υ includes the magnetic brush method using an iron powder carrier, the cascade method using a bead carrier, the fur brush method using a fan, etc., depending on the type of carrier that transports the toner. be.

In addition, the -component development method includes the powder cloud method in which toner particles are made into atomized FE, and the contact development method in which toner atf is brought into direct contact with the electrostatic latent image surface for development. method (also called contact development or toner development), toner particles f are not brought into direct contact with the electrostatic latent image surface, but are charged and caused to fly toward the latent image surface by the electric field of the electrostatic latent image. Jumbing development method, magnetic conductive toner is electrostatically P? There is a MagneDry method in which development is performed by contacting the If 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, a coloring agent dispersed in a binder resin such as polystyrene may be used in an amount of 1 to 30 μm. Particles pulverized to a size of about m 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, a toner such as Jl+1 is usually mixed with Gallya grains t such as Karaheeds and iron powder.

Also, the toner has a positive or negative charge depending on the polarity of the developed latent image. I can get it.

In order to impart charge to the toner, it is also possible to utilize only the J8'' triboelectricity of the resin, which 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. Therefore, in order to impart the desired tribostatic chargeability to the toner, a charge control agent such as a dye that enhances the chargeability or a charge controlling agent such as t'1 is added. It is.

However, in order to impart chargeability to the toner by adding these additives, these additives must be present on the surface of the toner to some extent. Therefore, these additives fall off from the toner surface due to the friction of the toner, collision with the carrier, rubbing with the electrostatic latent image carrier, etc., contaminating the gear rear, etc., and causing damage to the electrostatic latent image carrier, e.g. This may cause contamination of the photoreceptor belt or drum. As a result, the charging property deteriorates, and as the development operation is repeated, the deterioration progresses, the image density decreases, fine line reproducibility decreases, fog increases, etc., resulting in the Jitsukawa L problem.

The above-mentioned problems can be remedied by improving the affinity and dispersibility of the toner binder and additives such as dyes and pigments that impart elasticity or charge control agents, but these additives Surface treatment to increase the affinity for 1.0% tends to reduce charge imparting properties, and mechanically applying stronger shear and finer dispersion reduces the proportion of the additive that appears on the surface of 1.117 tons. There is a tendency that the characteristics are not sufficiently attached. For these reasons, the number of additives capable of imparting electrical properties to toners to a sufficiently satisfactory level is extremely limited, and only a few have been commercialized. In particular, in order to obtain not only a black and white image but also a color image, it is preferable that the charge control agent added to the toner be colorless, and in this case, there is almost no charge control agent that is satisfactory.

In view of this situation, toner is charged! The direction L of the j characteristic is achieved not only by toner additives, but also by conveyance, regulation, or friction members such as carriers, sleeves, and doctor plates that come into contact with toner during the development process (hereinafter, these are collectively referred to as "Charged t"
It has also been proposed that this can be achieved by changing the charging characteristics of the toner material (referred to as "J material"). In other words, in this specification, the term "charged material" refers to a material that comes into contact with the toner at or prior to the development ball and imparts or captures the charge necessary for development to the toner. Assistant crj f1
It is a material element 1 or member.

In this method of actively charging the toner with commercially available materials, there is almost no need to add additives to the toner to improve its dielectric properties. For example, the causes of contamination of carrier particles, photoreceptors, etc. are essentially reduced, and as a result, repeated development operations may reduce chargeability or reduce latent image formation. Further, it is possible to easily increase the If?' value without disturbing the color tone of the color toner.

[Problems to be Solved by the Invention] Charged materials such as carriers, sleeves, and doctor blades not only have a strong charging ability but also resist friction with toner and are durable. It has to be something. For example, it is desired that the carrier be used for a long period of time without being replaced, and the sleeve is required to have the same durability as the main body of the developing machine.

An object of the present invention is to provide a charge imparting material that solves the problem of the bending point as described in L above.

A further object of the present invention is to provide a charged material that applies an appropriate negative charge to toner.

A further object of the present invention is to provide a charged bowing member whose performance does not deteriorate even after long-term use.

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

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

[Means and operations for solving the problem] As a result of research to achieve the above-mentioned object, the inventors have arrived at the following invention.

That is, the present invention is a charge imparting material for developing electrostatic images characterized by having diorganotin phosphate at least on the surface.

It is unclear what is responsible for the charge-imparting properties of the diorganosudrin #salt of the present invention, but the Sn-0 bond is important.
It is thought to be in motion.

Therefore, the organo group bonded to tin is not particularly limited, but a group that increases the charge density of tin is preferable.

For example, alkyl groups such as methyl group, ethyl group, t-butyl group, octyl group, and lauryl group, cyclic alkyl groups such as cyclohexyl group and cyclopentyl group, and aryl groups such as phenyl group, naphthyl group, and anthryl group. group, an aralkyl group such as a benzyl group, a phenylethyl group, or a derivative having the above-mentioned substituent as a basic skeleton.

The diorganotin phosphate of the present invention is synthesized by a dehydration reaction between the corresponding diorganotin oxide and phosphoric acid.

For example, dibutyltin phosphate is synthesized by dehydrating dibutyltin oxide and phosphoric acid at a molar ratio of 3:1 to 1:3 in toluene under reflux.

The compound has an average particle diameter of 10 to 0.000000000000000 although it depends on the form of the charge-imparting material. OI4m, especially 2-0.
Preferably, the charged material is formed as particles of 14 m.

These compounds can be prepared by dipping, spraying, or dipping a coating solution obtained by dissolving or dispersing the compound in a solvent or dispersion agent together with a binder resin as necessary onto the base material of the charged J material.
It can be applied by a method such as eight coat coating, or if the base material is in the form of carrier particles, it can be mixed with the above coating liquid and vi'IA and then dried, or it can be directly mixed with the above compound using a fluidization head. By methods such as coating with
If 41 layers of the above compound are formed on the base material L, the wood invention'
1 [A loaded γ material is obtained. Also, directly with binder resin,
A charged T-material having a coating layer containing the above material may be obtained by melt-kneading and extrusion laminating onto a matrix. Furthermore, these compounds may be contained in a moldable resin, and this may be molded into the shape of carrier particles f, sleeves, or doctor blades to obtain a charged material.

As the pinter resin or molding resin, a resin with a cross-section 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 of polypropylene, silicone resin, Teflon, etc., their conjugates, or mixtures thereof are U7 products. After coating or molding, these resins can be made to have a crosslinked structure as required to improve the durability of the surface layer of the charged adhesive material.

When a pinter resin or a molding resin is used, it is preferable to use the compound in a ratio of 0.5 to 200 parts by weight, particularly 2 to 100 parts by weight, per 100 parts by weight of the resin.

When applying to the surface of a material loaded with 1 ton, it is necessary to appropriately control the coating or application amount of the compound, but if the material is 0.01mg/ca+2~10IIIg
/cm2, preferably 0.1mg/cm2
~2 mg/cm2 is good.

Also, through the case of Hokuki-ren, along with the above compounds,
Ceramic powders such as silica powder, aluminum mide, cerium oxide, and silicon carbide may be used as the filler. Further, a conductive adhesive such as carbon black or tin oxide may be used to adjust the conductivity. Furthermore, in order to prevent the spent toner from accumulating on the sleeve or carrier surface, a release agent such as a fatty acid metal salt, vinylidene fluoride, etc. may be used. All known carriers can be used as the base material of the charge imparting material in the form of a carrier, and metals such as iron, nickel, aluminum, and copper, powders of metals such as alloys, or metal oxides containing metal oxides or crystals can be used. ＆ Completed. Furthermore, power glass, SiC. Ceramic powder or particles such as BaTi02 and SrTi07 are used. Further, examples include those whose surfaces are treated with resin, resin powder, or resin powder containing magnetic material. The average particle diameter is preferably about 20 to 250 pm.

Furthermore, the base material of the charged pointed material in the form of a sleeve or doctor blade generally includes metals or alloys such as iron, aluminum, stainless steel, and nickel, and non-metallic compounds such as ceramics and plastics. Any available material can be used.

On the other hand, as toners to be used in combination with the above-mentioned charged material of the present invention, substantially all toners that have been used in conventional electrostatic image developing toners 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,
It may also contain magnetic powder. Furthermore, these toners may contain small amounts of charge-imparting substances, such as dyes, pigments, or so-called charge control agents, for more efficient charging, and fluidizing agents such as colloidal silica. , an abrasive such as cerium oxide, strontium titanate, and silicon carbide, and a lubricant such as stearin, vinylidene fluoride, etc. It may also contain conductive adhesives such as carbon black and tin oxide. As the developing method using the charged material and toner of the present invention described above, substantially all developing methods using a two-component developer or a one-component developer can be used.

For example, a magnetic brush development method, a cascade development method, a fur brush development method, a so-called microtoning development method using a magnetic material-containing resin powder as a carrier, a development method using a resin powder as a carrier, a so-called jumbing development method, etc. This is a jumping development method that develops non-magnetic toner.

[Example] The present invention will now be explained in more detail with reference to Examples.

Example 1 100 g of dibutyltin phosphate was dissolved and dispersed in MEKIJI, and an iron powder carrier (particle size: ″250 to 40
0mesh) I Kz was dispersed in a pole mill about 3
Stirred for 0 minutes.

After drying this iron powder carrier mixture and completely removing the solvent, light agglomerations were loosened 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 any particular load control agent.

Styrene 100 layered part (trade name: Raven 3500, manufactured by Caponto) The above materials were kneaded, pulverized, and classified to have a particle size of 1 to 30 μm.

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

When the amount of triboelectric charge of this developer was measured by the blow-off method, it was -9.8 1t. c/g.

When this developer was used to produce an image on a Canon 5JNP-5000 copying machine, there was no change in image density even in a durability test of 50,000 copies, and fine line reproducibility and gradation were good. There was also no force.

Example 2 Polymethyl methacrylate resin 100 in xylene 12
g was dissolved, and 50 gfi of dicyclohexyltin phosphate was added thereto. This was mixed with the same iron powder carrier as in Example 1 and dried to obtain a carrier with a charging effect.

When this was used and combined with toner in the same manner as in Example 1, the amount of triboelectric charge of the toner was -10.1 pc/g,
When we produced an image using this, the resulting image showed the same good image quality, fine line reproducibility, and gradation as the initial image, and there was no blurring even in a durability test of 50,000 sheets. .

Example 3 100% polymethyl methacrylate resin in 1 bottle of xylene
A solution of 50 g of dicutyl tin salt was mixed with 50 g of dicutyl tin salt. Add Ganon NP-400 to this solution.
Dip RE River's developing sleeve (made of stainless steel) and add 0.1mg/cm2 to 0.6mg/c onto the sleeve.
I wore a m2 coat.

This sleeve was placed in the original developing machine.

The toner was prepared according to the following recipe using a general kneading and pulverizing method.

Styrene-butyl methacrylate 100 parts by weight copolymer IVi approval = 300,000 lia type
Agent 4 parts (
Product name PE-130: Manufactured by Hoechst) Magnetic
Powder 60 Tonjakube (trade name: BL-200, manufactured by Titanium Kogyo Co., Ltd.) The toner prepared had a particle size of IILm to 30gm.

Using this toner, an image reproduction durability test was conducted using Canon MP-400RE.

There was no change in the image from the beginning after 50,000 sheets of durability, and the fine line II ■ development and gradation were good, and there was no capri.

In addition, when the surface potential of the sleeve was measured, it was -23V.
It was confirmed that the toner was completely negatively charged.

Example 4 A solution was prepared by dissolving 80 g of polycarbonate resin in xylene 12 and further mixing 20 g of di(pt-butylphenyl)tin phosphate. Dip the developing sleeve (made of aluminum) of the Aota cartridge developing machine for Canon PC-20 into this solution, and put O
．． A coating of lmg/cm2 to 0.5mg/cm2 was applied.

This sleeve was inserted into the original developing machine.

The toner was prepared according to the following recipe.

Poly(styrene-butylmethacrylic) 100 parts by weight
) 5 lab i support = 150,00
The particle sizes of the toners prepared were adjusted to IILm to 30ILm.

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

As a result, the image does not change until the toner runs out.
A clear 17-color image with good fine line reproducibility and gradation was obtained. Furthermore, we measured the surface potential of the toner on the sleeve.
It was 2.6v and was negatively charged.

[Effects of the Invention] As described above, according to the present invention, a toner for developing an electrostatic image, which has a compound having a specific structure as a charge control agent on its surface, is charged. material is provided. In particular, 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 applied to the surface of a charged material by coating or kneading and dispersing it. Provides a good charge imparting material with excellent durability downstream when used with toner.

Therefore, by using this charged material, it is possible to obtain a substantial improvement over the various problems that occur when a charged agent is mixed only into toner to improve its charging characteristics.

Current employee: Kiya Non Co., Ltd.

Claims (4)

[Claims] (1) A charge-imparting material for developing an electrostatic image, characterized in that it has a diorganotin phosphate at least on its surface. (2) The charge imparting material for developing an electrostatic image according to claim 1, which is in the form of carrier particles. (3) The charge imparting material for developing an electrostatic image according to claim 1, which is in the form of a cylindrical sleeve. (4) Claim 1 in the form of a doctor blade
A charge imparting material for developing an electrostatic image as described in 2.