JPS6331775B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developing powder (hereinafter referred to as a toner) used for developing an electrostatic image, and particularly to an electrostatic developing toner having improved lubricity and fluidity.

Conventionally, as an electrophotographic method, U.S. Patent No.
A number of methods are described in Japanese Patent Publication No. 2297691, Japanese Patent Publication No. 42-23910, Japanese Patent Publication No. 24748-1974, etc., but generally, photoconductive substances are used,
An electrical latent image is formed on the photoreceptor by various means, and then the latent image is developed using toner and, if necessary, the powder image is transferred to paper, etc., and then heated and pressurized or by solvent vapor, etc. This is to obtain a fixed copy. Examples of methods for visualizing electrical latent images using toner include the magnetic brush method described in U.S. Pat. No. 2,874,063, the cascade development method described in U.S. Pat. No. 2,618,552, and
The powder cloud method described in No. 2221776 is known. Toners used in these developing methods include fine powders in which dyes and pigments are dispersed in a binder, as well as those in Japanese Patent Publications No. 11096/1986 and No. 40.
Toners to which a third substance is added are known, as described in JP-A-10866 and JP-A-44-6398. By the way, such developing methods can be roughly divided into wet methods and dry methods, and when a wet method is used, a highly insulating solvent such as Isopar H is used.
(Product Name) etc. indirectly act effectively as a lubricant to reduce the coefficient of friction between the photoreceptor and the cleaning blade, allowing the cleaning operation to be carried out smoothly. However, in the dry developing method, an alternative lubrication method is required, and in the past, lubrication methods such as polytetrafluoroethylene, polyethylene, stearic acid metal salts, molybdenum disulfide, etc. have been added externally to the dry developing agent. Attempts to improve the lubricity and cleaning properties on photoreceptors by adding a single substance such as graphite or the like as a lubricant are well known. However, since the lubricant is added to the developer using an external addition method, (1) the concentration of the toner and lubricant in the developer gradually loses balance during use, and (2) the image quality deteriorates as a result. Changes in concentration become noticeable (3)
In addition, there remain problems such as poor film formation on the photoconductor, which is thought to be caused by the lubricant, and (4) the addition of the lubricant reduces the fluidity of the toner. Although studies have been made to regulate the type and amount added, as well as fluidity improvers, it has been difficult to reach a practical level.

Therefore, in the present invention, good lubricity on the photoconductor indirectly improves the abrasion resistance of the cleaning blade, thereby providing a permanently good copy image, and The main object of the present invention is to provide a toner for electrostatic charge development in which the fluidity of the toner in a cleaner is improved.

Furthermore, it is an object of the present invention to provide a toner for electrostatic charge development that can prevent film formation on a photoreceptor due to fusion development and can permanently provide good images without image fogging. For other purposes.

That is, the present invention provides a toner for electrostatic charge development, characterized in that a silane coupling agent and a lubricant are internally added together with a coloring agent in a resin serving as a toner matrix; a resin serving as a toner matrix, a coloring agent, A method for producing toner for electrostatic charge development, characterized by premixing a silane coupling agent and a lubricant, melting and kneading the resulting mixture, cooling and pulverizing; and forming an electrical latent image on a photoreceptor. In this developing method, the latent image is developed to form a toner powder image, the powder image is transferred, and the surface of the photoreceptor is cleaned after the transfer. It is an object of the present invention to provide a developing method characterized in that a ring agent and a lubricant are internally added, and the photoreceptor after transfer is cleaned with a cleaning blade.

In the present invention, colorants (for example, pigments,
This is a toner for electrostatic charge development which contains a dye (dye) dispersed therein, to which a silane coupling agent and a lubricant are further added.

Examples of the lubricant used in the present invention include talc, polytetrafluoroethylene, polyethylene, higher fatty acid metal salts, higher fatty acid amides, higher fatty acid esters, and paraffin wax.
These lubricants can be used alone or in combination.
It was particularly preferred to use talc mixed with other materials. According to the studies conducted by the present inventors, talc is a particularly effective component for improving the lubricity of toner, but the image quality of copies obtained from the toner or the film-forming property of the toner on the photoconductor may be affected. Considering the occurrence of secondary defects such as
It is 2% (by weight) based on the resin.

That is, according to a comprehensive judgment, it is preferable that the amount of talc to be used is defined in the range of 0.01 to 2% (by weight) based on the resin component.

In the present invention, it is preferable to use another lubricating component in addition to talc in order to avoid the above-mentioned secondary defects and to further improve the toner lubricity. The amount of lubricant added is 0.05 to the toner resin component.
It is best used in a range of ~20% (by weight).

Furthermore, the silane coupling agent used in the present invention significantly improves the fluidity of the toner and does not impair the electrophotographic properties. Commercially available silane coupling agents are sufficient, such as vinyl chlorosilane, vinyl-trus(β-methoxy)silane, vinyltriethoxysilane, γ-methacryloxypropyl, trimethoxysilane,
Vinyltriacetoxysilane and the like.

These silane coupling agents are preferably added in an amount of 0.1 to 20% (by weight), particularly 0.5 to 10% (by weight), based on the resin component.

The electrostatic charge developing toner of the present invention can be produced, for example, by the following method. That is, after adding polystyrene resin and chlorinated paraffin, for example, carbon black as a pigment, a silane coupling agent, and a lubricant in predetermined amounts, premixing them with a vibration mill, and melting and kneading the powder with a roll mill, The toner is coarsely ground with a hammer mill and further finely ground with a jet mill to obtain a toner with a particle size of about 5 to 20 microns. The toner thus obtained is mixed with carrier iron powder (trade name: EF300-500 (manufactured by Nippon Steel Powder)) (toner concentration 15%) to form a developer.
The developer may be used, for example, in a dry electronic copying machine (trade name: NP1100, commercially available) equipped with a cleaning blade.
Good results can be obtained when copying is performed using a Canon (manufactured by Canon) camera. The present invention will be explained in more detail with reference to Examples below.

In addition, the parts in the examples are shown in parts by weight unless otherwise specified.

Example 1 100 parts of chlorinated paraffin (binder resin), 50 parts of polystyrene, 50 parts of styrene-butadiene copolymer
9 parts carbon black, 2 parts spirone (dye)
part, 2 parts of Gunjiyo, 1.0 part of talcum,
The above ingredients, including 0.5 parts of polyethylene and 2 parts of vinyl-tolyl (β-methoxyethoxy) silane, are thoroughly stirred and mixed in a Henschel mixer and pulverized.

This mixture is then placed in a roll mill and the temperature
The mixture was heated and melted at 140 to 150° C. for about 30 minutes, cooled to room temperature, and the resulting melt was coarsely ground using a grinder and then finely ground to produce a toner having a particle size of 5 to 6 μm. This sample is designated as A. For reference, a toner was produced in the same manner using the same composition except that talc, polyethylene, and vinyl-trous (β-methoxyethoxy) silane were omitted from among the above components.
This was designated as sample B.

The obtained toner samples A and B were mixed with carrier iron powder at a ratio of toner/carrier = 15/85 to prepare a developer. By applying these two types of developers, the Se photoreceptor drum (support: Al
The copying process was performed under the following conditions: cylinder, photosensitive layer: vapor-deposited Se, 60μ, insulating layer: photocurable acrylic urethane (30μ), and urethane cleaning blade (hardness, 70°, angle to the insulating layer surface: 30°, blade load: 20 kg). As a result of testing the lubricity, image performance, durability, and toner fluidity, it was found that when developer sample A was used, the friction coefficient between the photoreceptor and the cleaning blade was 1.01, and the drum ran smoothly. It rotated, and the image was good. Especially, no change was observed between the initial image and the image density after 30,000 rotations, and the triboelectric potential of the developer did not change either.
No film formation was observed due to damage or developer fusion phenomenon. On the other hand, when developer sample B is used, the friction coefficient between the photoreceptor and the cleaning blade is 2.70.
When the drum rotates 50 times, the sliding noise (friction noise between the blade and the insulation layer) is intense, and the blade edge wears out.
Cleaning scratches on the insulating layer were clearly observed.

Furthermore, the angle of repose of toner A and B is 38° for A and 42° for B, and the difference in fluidity is also clear. In A, the angle was 48° when no silane coupling agent was added.

Example 2 100 parts of chlorinated paraffin, 50 parts of polystyrene,
50 parts of styrene-butadiene copolymer, 9 parts of carbon black, 2 parts of spirone, 2 parts of gunjiyo, 1.8 parts of talc, 3.5 parts of calcium oleate, and
3 parts of γ-aminopropyltriethoxysilane, a toner was produced in the same manner as in Example 1 from the above composition, mixed with a carrier to form a developer, and then
When the same copying process as in Example 1 was carried out and the results were investigated, it was found that the friction coefficient was 1.01, the drum rotated smoothly, the image was good, and in particular, no change was observed between the initial image and the image density after 30,000 rotations. Moreover, the tribopotential of the developer did not change, the fluidity of the toner was good, and no wear or breakage of the blade edge, and no film-forming properties due to the fusion phenomenon of the developer were observed.

Example 3 100 parts of chlorinated paraffin, 50 parts of polystyrene,
50 parts of styrene-butadiene copolymer, 9 parts of carbon black, 2 parts of spirone, 2 parts of gunjiyo, 0.8 parts of talc, 1.0 parts of calcium stearate, and 7 parts of γ-chloropropyltrimethoxysilane,
A developer was prepared by processing the composition consisting of the following in the same manner as in Example 1.

This developer sample was designated as C.

Separately, 3 parts of polytetrafluoroethylene was added (externally added) to the toner sample B produced in Example 1, and the mixture was stirred in a ball mill, and a carrier was mixed with the resultant mixture to prepare a developer sample D.

Applying the above two developer samples C and D, the Carlson process of primary DC charging and image exposure was carried out.
Se photoreceptor (Al cylinder: support, photosensitive layer
Se65μ), urethane cleaning blade (hardness
70°, angle to photosensitive layer 30°, blade load 1.3
As a result of a copying test conducted under the conditions of use (Kg), when Sample D was used, the friction coefficient between the photoconductor ← → cleaning blade was 1.05, and a change in image density was observed on the drum, and a change was observed in the densiometer. When measured with
Decreased from 1.45 to 0.85. In addition, a change in the tribopotential of the developer itself was observed between the initial stage and after 2000 rotations, and the ability to form a toner film on the photoreceptor was observed. The change in image density was caused by a marked increase in the angle of repose due to deterioration of toner fluidity.

On the other hand, when sample C was used, the friction coefficient between the photoreceptor and the cleaning blade was 1.02, and the drum rotated smoothly, and no change in image density or film formation due to developer fusion was observed. .

Example 4 100 parts of chlorinated paraffin, 50 parts of polystyrene,
Styrene-butadiene copolymer 50 parts, carbon black 9 parts, spirone 2 parts, gunjiyo 2 parts, talc 0.9 parts, paraffin wax (melting point 135°C) 1 part
A developer was prepared by treating a composition consisting of 1 part and 2 parts of vinyltriethoxysilane in the same manner as in Example 1. This developer sample was designated as E.

Separately, a composition consisting of 100 parts of chlorinated paraffin, 50 parts of polystyrene, 50 parts of styrene-butadiene copolymer, 9 parts of carbon black, 2 parts of Spiron, 2 parts of Gunjiyo, and 2 parts of lead stearate was prepared in the same manner as in Example 1. A developer was prepared by processing. This developer sample was designated as F. Although this sample F is not within the scope of the present invention, it is provided as an example for reference. A copying test similar to that in Example 1 was conducted using the two types of developer materials E and F mentioned above. As a result, when sample E was used, the friction coefficient between the photoreceptor and the cleaning blade was 1.05. The drum rotated smoothly, and no changes in image density, toner film formation on the photoreceptor, or image fogging were observed, and no wear on the blade edges was observed, resulting in a good image. However,
When sample F is used, the friction coefficient between the photoreceptor and the cleaning blade is 1.07, and the drum rotates smoothly, but the developer is deposited in spots during the "solid white" state with proper exposure. A fogging phenomenon was observed and good images could not be obtained.

Example 5 A toner was produced in exactly the same manner as in Example 1 except that polyethylene was replaced with tetrafluoroethylene, and a copying test was conducted in the same manner as in Example 1. The results were as follows. It was almost the same.

Example 6 80 parts of polystyrene, 20 parts of phenolic resin, 40 parts of chlorinated paraffin, 10 parts of carbon black, 2 parts of spirone, 2 parts of gunjiyo, 1.5 parts of talc, 3.5 parts of zinc palmitate and 2 parts of γ-methacryloxypropyltrimethoxysilane A developer was prepared by processing a composition consisting of The friction coefficient between the two is 1.01, and the drum rotates smoothly.
The image was good, especially no change was observed between the initial image and the image density after 30,000 rotations, and the triboelectric potential of the developer also did not change, indicating that the film formation was due to abrasion or damage to the blade edge, or a fusion phenomenon of the developer. Gender was not confirmed.

In addition, of the above composition, only zinc palmitate was replaced with magnesium oleate, lead caprylate, calcium caproate, copper linolenate, and iron linoleate, respectively, and the other things were carried out in the same manner, and the copying results were almost the same. It was hot.

Example 7 A composition consisting of 100 parts of epoxy resin, 3 parts of Direct Yellow 26 (dye), 0.2 parts of talc, 1.8 parts of olein and 5 parts of vinylchlorosilane was prepared in Example 1.
A developer was prepared by processing in the same manner as in Example 1, and a copying test similar to that in Example 1 was conducted using this developer. As a result, the friction coefficient between the photoconductor ← and the cleaning blade was 1.10, and the photoconductor drum It rotated smoothly and the copied images were good.

Further, the results were similar to those of the treatment described above, which was carried out in the same manner except that olein was replaced with oleoamide in the above composition.

Reference Example The toner made from the same materials except talc and polyethylene in Example 1 has insufficient lubricity for practical purposes, but the fluidity of the toner made with the addition of a coupling agent is very good. It was in good condition.

As detailed above, by using the electrostatic charge developing toner of the present invention, the lubricity on the photoconductor, the abrasion resistance of the cleaning blade are improved, and the film formation on the photoconductor due to the fusion phenomenon of the developer is improved. It was possible to prevent and eliminate the image fogging phenomenon, provide a permanently good image, improve the fluidity of the developer, and have good transfer efficiency.

Claims (1)

[Scope of Claims] 1. In a toner for electrostatic charge development used in a developing method that includes a step of cleaning the surface of a photoreceptor with a cleaning blade, a silane coupling agent and a lubricant are contained in a resin serving as a toner base together with a coloring agent. A toner for electrostatic charge development, characterized in that it contains therein. 2. In a method for manufacturing a toner used in a developing method that includes a step of cleaning the surface of a photoreceptor with a cleaning blade, a resin serving as a toner base,
A method for producing a toner for electrostatic charge development, which comprises premixing a coloring agent, a silane coupling agent, and a lubricant, melt-kneading the resulting mixture, cooling it, and then pulverizing it. 3 forming an electrical latent image on a photoreceptor, developing the latent image to form a toner powder image, and transferring the powder image;
In a developing method that cleans the surface of the photoreceptor after transfer, the toner is a toner in which a colorant, a silane coupling agent, and a lubricant are internally added to the toner base resin, and the photoreceptor after transfer is cleaned by a cleaning blade. A developing method characterized by cleaning.