JPS62141569A - Charge applying material for developing electrostatic charge image - Google Patents

Abstract

PURPOSE:To obtain a charge applying material having excellent durability by having a specific compd. contg. an organo group on the surface of said material. CONSTITUTION:This material has the compd. expressed by formula on at least the surface. In formula, R<1>, R<2> denote the organo group, M denotes the group IIIA elements of periodic table and X denotes a monovalent substituent. A coating liquid prepd. by dissolving or dispersing such compd. together with a binder resin into a solvent or dispersion medium is coated on the surface by a dipping or spraying method or brushing, etc., or if the base material is in the form of carrier particles, the material is dipped in or mixed with the coating liquid and is dried or the coating layer is formed on the base material by coating with a fluidized bed of the direct mixture composed of such particles and the compd.

Description

[Detailed Description 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. The present invention relates to a material or member, that is, a charge imparting material (herein, the word "material" is used to include granular materials in addition to members having a regular shape).
'1'' uL Kichi Previously, 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 Application No. 24748, etc., but these methods basically involve applying a uniform electrostatic charge on a photoconductive insulating layer and irradiating the insulating layer with a light image. An electrostatic latent image is formed, and then the latent image is developed and visualized using a fine powder called toner using the wave flux. After transferring the powder image to paper etc. as necessary, the image is transferred by heating, pressure, or solvent vapor. 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 is further divided into a method using a two-component developer and a method using a -component developer. The conventional methods that yield to the two-component development method include a magnetic brush method using an iron powder carrier, a cascade method using a vinyl carrier, a fur brush method using fur, etc., depending on the type of carrier that transports the toner.

In addition, methods that yield to -component development methods 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; and magnetic conductive method. There is the MagneDry method, which develops by bringing a toner into contact with the electrostatic latent image surface.

Conventionally, toners used in these development methods are fine powders in which dye pigments are dispersed in natural or synthetic resins.For example, toners in which colorants are dispersed in binder resins such as polystyrene are used. Finely pulverized particles of about 1 to 30 IL are used as toner. Also, as a magnetic toner, instead of the dye or pigment described above.

Alternatively, in addition to this, a material containing magnetic particles such as yagnetite is used.

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

Furthermore, the toner is given a positive or negative charge in advance depending on the magnetism 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 above-mentioned problems are caused by the affinity between the toner binder and additives such as dyes and pigments that impart chargeability or charge control agents.
This can be improved by improving dispersibility, but surface treatment to increase affinity for these additives often results in a decrease in charge imparting properties.Furthermore, if strong mechanical shear is applied to finely disperse the toner, As a result, the proportion of additives released tends to decrease, and charging properties tend not to be sufficiently imparted.For these reasons, it is extremely difficult to find additives that can impart chargeability to a toner to a level that satisfies the needs of practical use. In particular, it is preferable that the charge control agent added only to black-and-white images be colorless, and in this case, there are few that are practically satisfactory6.
, 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 transportation, regulation, or It has also been proposed to improve the charge imparting properties of friction members (herein referred to collectively as "r-charge imparting materials") to toner. In other words, the term "charge-imparting material" as used herein refers to a material that can contact the toner during or prior to the development process and impart the charge necessary for development 9 to the toner or retain the charge. It is a member.

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, contamination sources such as carrier particles and photoreceptors are reduced in a wood-based manner,
Therefore, repeated development operations do not reduce chargeability or disturb the latent image. Furthermore, the color toner can be easily charged without impairing its color tone.

In addition, charge-imparting materials such as carriers, sleeves, and doctor blades must not only have a strong charge-imparting ability, but must also be able to withstand friction with toner and be durable. 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.

11 11 An object of the present invention is to provide a charge imparting material that solves the above-mentioned problems.

A further object of the present invention 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 that provides images with excellent fine line reproducibility and gradation.

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

11 Side 11 The present invention resides in a charge imparting material for developing an electrostatic image, which is characterized by having a compound represented by the following general formula [I] on at least the surface thereof.

RIR2n tile (MX) view [11 The reason why the above compound has excellent charge control ability is not clear, but it is understood that the Sn-0-M bond part in the above compound plays an important role as a charge control agent. be done. Therefore, the above general formula [I
R1, R2, and X in ] may basically be any group, however, in terms of the synthesis method, X is generally as described below.

For example, R1 and R2 are an alkyl group such as a methyl group, an ethyl group, a n-butyl group, a t-butyl group, an octyl group, or a lauryl group; a cyclic alkyl group such as a cyclohexyl group or a cyclopentyl group; a phenyl group or a naphthyl group; Aryl groups such as anthryl group; benzyl group, phenylethyl group,
7ralkyl groups such as; acyl groups such as acetyl group, benzoyl group; fulkenyl groups such as vinyl group, allyl group, impropenyl group; alkynyl groups such as ethyl group and 2-propynyl group, or the above-mentioned substituents. 1M, which is a derivative having a skeleton, represents aluminum or boron, and X represents a hydroxyl group, an alkyl group, a 7-ary group, or a derivative having these as a basic skeleton.The present invention will be explained in more detail below. In the following description, 1 represents a quantitative ratio.
"Parts" and "%" are based on weight unless otherwise specified.

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

[Compound example]

H3 (-1) (to H2- to R123n(J (B
(JtlNori) These compounds are synthesized as follows.

Diorganomercury (R2Hg) is added to tin chloride (SnC12).
) to obtain diorganotin dichloride. Next, it is synthesized by reacting diorganotin dichloride with boric acid, organoborin, or aluminum hydroxide.

For example, compound example (1) is synthesized in the first order.

Dibutylmercury is reacted with tin chloride using ether as a solvent to obtain dibutyltin dichloride. After separating this by filtration, dibutyltin dichloride is treated with boric acid to yield Compound Example (1) as scuttling.

Furthermore, when R1 and R2 are different, the asymmetric diorganotin dichloride may be reacted with boric acid, diorganoborine, or aluminum hydroxide, and the asymmetric diorganotin dichloride can be synthesized as follows.

That is, tin chloride (S nCl 2 ) is reacted with organochloride to obtain organotin trichloride. Then, organotin trichloride is reacted with organolithium in ether to obtain asymmetric organotin dichloride.

For example, compound example (13) is synthesized as follows.

Butyl chloride is reacted with tin chloride to obtain butyltin trichloride, which is then dissolved in ether.

This ether solution is treated with an ether solution of phenyllithium to obtain butylphenyltin dichloride. After filtration, compound example (13) is obtained by acting with boric acid.

The above compound generally has an average particle size of 10 to 0.01#L, particularly 2 to 0.01#L, although it depends on the form of the charge imparting material to be applied.
It is preferable to use the particles of IIL to form a charge imparting material.

These compounds can be dissolved or dispersed in a solvent or dispersion medium together with a binder resin as necessary, and a coating solution obtained is applied to the base material of the charge-imparting material by dipping, spraying, coating, etc. When the base material is in the form of carrier particles, the above-mentioned compound can be applied to the remote layer by a method such as immersion mixing this with the above-mentioned coating solution and then drying it, or a method such as coating 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. Alternatively, a charge imparting material having a coating layer containing the above material may be obtained by directly melt-kneading it with a binder resin and extrusion laminating it on top of a resin. the carrier particles,
It may be formed into the shape of a sleeve or doctor blade and used as a charge imparting material.

As the binder resin or molding resin, common resins can be used. For example, polystyrene, polyacrylic ester, polymethacrylic ester, polyacrylonitrile, rubber resins such as isoprene and butadiene, polyester, polyurethane, polyamide, Epoxy resins, rosins, polycarbonates, phenolic resins, chlorinated paraffins, polyethylene, polypropylene, silicone resins, Teflon, derivatives thereof, copolymers thereof, or mixtures thereof can be used.

After coating or molding, these resins can be made to have a crosslinked structure as 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 per 100 parts of the binder resin or molding resin.

When coating the surface of the charge-imparting material, it is necessary to appropriately control the coating or coating amount of the compound, but it is preferable that the material is 0.01 mg/cm2 to lomg/cm2.
The range of cm2 is good, but preferably O, l m g /
cm 2 to 2 mg/cm 2 is good.

In addition, through the above series of cases, ceramic powders such as silica powder, aluminum oxide, cerium oxide, and silicon carbide may be used as fillers in addition to the above-mentioned compounds, and conductivity-imparting materials such as carbon black and tin oxide may be used as fillers. In addition, to prevent the accumulation of spent toner on the sleeve or carrier surface, agents such as 1111m type agents may be used, such as fatty acid metal salts.

Vinylidene fluoride or the like may also be used.

All known carriers can be used as the base material for the charge-imparting material in the form of a carrier, including iron and iron.

Powder or particles of metals such as nickel, aluminum, copper, alloys, or metal compounds containing metal oxides, as well as glass and StC.

Ceramic powder or particles such as BaTiO2 and SrTiO2 are used. Also, those whose surfaces are treated with resin etc.

Examples include resin powder or resin powder containing a magnetic substance. The average particle size is preferably about 20 to 250 particles.

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 the toner to be used in combination with the charge imparting material of the present invention as described above, those 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 coloring agent in a binder resin, and may contain magnetic powder if necessary. In order to
Alternatively, it may contain a so-called load TL control agent, a fluidizing agent such as colloidal silica, an abrasive such as cerium ferment, strontium titanate, silicon carbide, a lubricant such as metal stearate, vinylidene fluoride, etc. It may also contain conductivity-imparting materials such as carbon black and tin oxide.

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, a magnetic brush development method, a cascade development method, a fur brush development method, a so-called micro-training 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 jumping development method, or This is a jumping development method that develops non-magnetic toner.

11 Rikuo] As described above, according to the present invention, there is provided a charge imparting material for imparting a charge to a toner for developing an electrostatic image, which has a compound having a specific structure as a charge control agent on its surface. be done. 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 charge-imparting material by coating or kneading and dispersing it. To provide a good charge imparting material with excellent durability when used in 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.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

100g of compound example 1 was dissolved and dispersed in MEKljl, and iron powder carrier (particle size: 250-400mesh) 1
Kg was dispersed and stirred in a ball mill for about 30 minutes.

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.

A toner was prepared using a separate primary formulation without adding any charge control agent.

Knead, crush, and classify the materials listed above to a particle size of 1 to 30 gm.
Aligned.

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

The amount of triboelectric charge of this developer was measured by a blow-off method and was found to be -9.2 JLc/g.

When images were produced using this developer using a Canon NP-5000 copying machine, there was no change in image density, fine line reproducibility was good, and gradation was also good. There was also no fog.

Support Ti+ Polymethyl methacrylate resin 100 in xylene 11
g was dissolved, and 50 g of Compound Example 2 was further mixed thereto.

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 -8.8 pc/g, and when images were produced using this, the resulting images had good image density. , it exhibited fine line reproducibility of one gradation and no fog.

[ul] Polymethyl methacrylate resin 100% in xylene 11%
A solution was prepared by dissolving 50 g of Compound Example 3. Dip a developing sleeve (stainless steel) for Canon NP-400RE in this solution, and place O on the sleeve.
, l m g /cm 2 to 0.6 mg/cm 2 .

This sleeve was placed in the original developing machine. The toner was prepared according to the following recipe using a general cross-mixing and crushing method.

Poly(styrene-butyl methacrylate) (M w −
3300,000) 100 parts mold release agent (product name P
E-130: manufactured by Hoechst Co., Ltd.) 4 parts Magnetic powder (trade name BL-200: manufactured by Titan Kogyo Co., Ltd.) 60 parts The prepared toner had a particle size of 1 μm to 30 μm.

Using this toner, we conducted an image printing durability test on Canon's NP-400RE. There was no change in the image, fine line reproducibility was good, and there was no fog. Also, when we measured the surface potential on the sleeve, it was found to be -357. It was confirmed that the toner was negatively charged.

A solution was prepared by dissolving 80 g of polycarbonate resin in xylene 1f and further mixing 20 g of Compound Example 4.

Dip the developing sleeve (made of aluminum) of the Canon PC-20 blue cartridge developing machine into this solution, and add 0.1 mg/cm2 onto the sleeve.
A coat of ~0.5 mg/cm2 was applied.

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) (MW=
150,000) 100 parts S-type agent (trade name PE-130: manufactured by Hoechst) 4 parts Blue youth agent (phthalocyan pigment) 6 parts The prepared toner had a particle size of 1. I finished it at the end of ~30.

Using this toner and a developing machine equipped with the above-mentioned sleeve, the PC-20 was modified to enable reversal development.
Funaku's image was published.

As a result, there is no change in one image 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
-31V and was negatively charged.

The compound examples used in Examples 1 to 4 are, in order, Compound Example 5 (Example 5), Compound Example 6 (Example 6),
Compound Example 7 (Example 7).

Example 1 except for replacing with Compound Example 8 (Example 8)
It was carried out in the same manner as in 4 to 4, and satisfactory results were obtained.

In addition, the correspondingly measured triboelectric charge amount and surface potential were as follows.

Claims (1)

[Scope of Claims] 1. A charge-imparting material for developing electrostatic images, which has a compound represented by the following general formula on at least its surface. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [I] (In the formula, R^1 and R^2 represent an organo group, M represents an element of group IIIA in the periodic table, and X represents a monovalent substituent. )