JPH02158768A - Developing device - Google Patents

Abstract

PURPOSE:To obtain a satisfactory picture after consecutive copying by coating the surface of a toner supplying member with a constituent containing a prescribed compound. CONSTITUTION:After toner is supplied to the toner supplying member 4, it is supplied to a toner carrying member 2, forms a thin layer via a toner layer thickness regulating member 3 for regulating a thickness of a toner layer, and is supplied to a latent image carrier 1, thereby developing a latent image. At least the surface of the toner supplying member 4 is coated with constituent containing at least one compound out of the compounds represented by a formula I, where R1 and R2 are H, lower alkyl radical, NH2, etc., M is Zn, Co, etc., and (n) is a valence number of M. Thus, abnormality is not found in a picture after consecutive copying, and picture quality equal to that in an early stage can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a developing device, particularly a developing device using a -component developer.

[Prior art]

Dry developing systems employed in electrophotography, electrostatic recording, and the like include systems that use a two-component developer consisting of toner and carrier, and systems that use a single-component developer that does not contain a carrier. The former method allows relatively stable and good images to be obtained, but it is difficult to obtain constant quality over a long period of time because carrier deterioration and the mixing ratio of toner and carrier tend to fluctuate. ,Also.

There are difficulties in maintaining the equipment and making it more compact.

Therefore, the latter method using a two-component developer, which does not have these drawbacks, is attracting attention.

By the way, in this method, the toner (developer) is usually conveyed by at least one toner conveying member, and means for visualizing the electrostatic latent image formed on the latent image carrier by the conveyed toner is provided. However, at that time,
It is believed that the layer thickness of the toner conveyed on the surface of the toner conveying member must be made as thin as possible. This applies even when using a two-component developer with a carrier of a very small diameter, and is particularly true when using a two-component developer with a high electrical resistance toner. When used, it is necessary to charge this toner with a developing device, so the toner layer thickness must be extremely thin. If this layer thickness is thick, only the near surface of the toner layer will be charged, and the entire toner layer will be uniformly charged. This is because it becomes difficult to be charged.

In response to these demands, various methods have been proposed as means for regulating the toner layer thickness on the toner transport member (toner layer thickness regulating means), and a typical example is to use a doctor blade and place this blade on the toner transport member. They are placed opposite each other, and the toner conveyed on the surface of the toner conveying member is pressed down by a pressing member (doctor blade) to control the toner layer thickness.

However, with this alone, it is difficult to uniformly convey the toner to the toner conveying member. Therefore, a developing device has been proposed that has a toner supply means that is rotatably supported in contact with a toner conveying member and supplies toner onto the toner conveying member. However, if development is performed continuously, The ability to supply toner to the toner conveying member is reduced.

This results in a decrease in image density. The cause of this is
There are two problems: a decrease in the ability to replenish toner from the toner hopper to the toner supply member, and a decrease in the ability to replenish toner from the toner supply member to the toner transport member. In order to solve the above-mentioned drawbacks, attempts have been made to add surfactant substances and fluidity modifiers to the toner, but the problem has not yet been solved satisfactorily.

〔the purpose〕

The present invention is a one-component development method for electrophotography in which a thin toner layer is formed on a toner conveying member and development is performed to obtain high-quality images. It is an object of the present invention to provide a developing device that can obtain equivalent image quality.

〔composition〕

The one-component development method of the present invention includes at least a toner conveying member and a toner layer thickness regulating member, and a toner supplying member that is rotatably supported while in contact with the toner conveying member and supplies toner to the toner conveying member. The invention relates to a developing device having: after toner is supplied to the supply member;
The toner is supplied to the toner conveying member and is further thinned through a toner layer thickness regulating member that regulates the toner layer thickness.
Next, a method for developing a latent image by supplying the toner to a latent image carrier will be described.

The inventors of the present invention have conducted extensive studies and found that when positively charging toner is used in the developing device, the above-mentioned conventional drawbacks can be solved by supplying at least the toner with a composition containing at least one compound selected from the compounds represented by the following general formula. The problem was solved by coating the surface of the member, and more preferably by using a developing device equipped with means for applying a bias of 0 to soo v positive potential to the toner supply member from the toner transport member.

General formula (However, R□, R2: H, lower alkyl group of C1 to C, NH2, alkylamino group M: Zn, Co, Ni, Fe, Ten: valence number of M) The cause of the above solution is Although it is not certain, by coating the toner supply member with a composition containing at least one compound selected from the compounds represented by the above general formula, the positively charged toner in the toner tank of the developing section can be smoothly transferred to the toner supply member. By applying a negative potential bias of 0 to 500 V from the toner transporting member to the toner supplying member, the toner on the toner supplying member is smoothly supplied onto the toner transporting member without stagnation, This is thought to be because the toner flow within the developing device becomes smoother, and the thickness of the toner layer on the toner transport member can always be kept uniform.

Examples of compositions containing at least one compound selected from the compounds represented by the following general formula used in the present invention include the following.

(Hereinafter, blank space) (Hereinafter, blank space) The toner supply member of the present invention may be made of a sponge-like material, a fur brush-like material, etc., and it is also conceivable that they are made of a conductive material. However, as a method for coating the surface of a toner supply member with the substance of the present invention, the toner supply member may be coated in a coating liquid obtained by dissolving or dispersing the substance in a solvent or dispersion medium as necessary. It can be applied by dipping, spraying, brushing, etc. The solvent used here is acetone.

Organic solvents such as benzene and ethanol are suitable.

In addition, the composition for coating a toner supply member contains one specific compound of the present invention, polystyrene, polyacrylic ester,
Rubber resins such as polymethacrylic acid ester, polyacrylonitrile, polyisoprene and polybutadiene, polyethylene, polypropylene, polyester, and polyurethane.

polyamide. Epoxy resin, polycarbonate, rosin, phenolic resin, chlorinated paraffin.

Resins such as silicone resins, Teflon, derivatives thereof, copolymers thereof, and mixtures thereof (
8) with the specific compound (A) of the present invention: A:B=100:
It may be added in a ratio of 0 to 5:95.

Addition of these resins has the effect of improving the durability of the toner supply member of the present invention.

What is important in the present invention is that the surface of the toner supply member is treated with a substance that shows negative chargeability to the toner. If the material does not show negative chargeability, the toner is removed by the toner supply member. In fact, the toner is not sufficiently charged by friction and the supply member is not sufficiently supplied with toner, and furthermore, the toner is not sufficiently supplied to the toner conveying member, making it impossible to obtain a uniformly charged toner thin layer. What is even more important is that the coating material on the surface of the toner supply member must be stable and positively charged to the toner, without changing thermally or over time, even after long-term use. be.

In addition, the toner supply member has a 0 to +50
By applying a bias of 0 V, toner is quickly replenished from the toner supply member onto the toner transport member. If the applied bias is a negative potential, the transfer of toner onto the conveyance member will be insufficient, and if it is more positive than +500V, toner filming will occur on the toner conveyance member, and background fog etc. will occur in the image due to running. arise above.

As the toner used in the developing device of the present invention, substantially all of the toners conventionally used as positively chargeable toners for electrostatic charge development can be effectively used.

That is, both non-magnetic and magnetic toners are used.

Furthermore, the toner is a colored particle in which a colorant is dispersed in a binder resin, and may also contain a dye, a pigment, or a so-called charge control agent to impart a charge. Also,
If necessary, a fluidity improver such as colloidal silica, an abrasive such as cerium oxide or silicon carbide, a lubricant such as a metal stearate, a conductivity imparting agent such as tin oxide, etc. may be contained.

The present invention will be explained below with reference to Examples.

Example 1 Styrenic resin (D-125 manufactured by Esso) 85 parts by weight Carbon black (#44 manufactured by Mitsubishi Carbon) 12 parts by weight Nigrosine dye 3 parts by weight After the mixture of the above composition was thoroughly stirred and mixed in a Henschel mixer, The mixture is melt-kneaded using a hot roll mill, cooled to room temperature, coarsely ground using a hammer mill, and then finely ground using an air jet mill. The obtained fine powder was classified to obtain a toner having a particle size of 5 to 25 μm.

Next, the following composition was prepared using a ball mill at room temperature for 10 minutes.
A toner supplying member made of a sponge-like material was immersed in the coating solution obtained by dispersing and dissolving the solution over time, and the solvent was completely evaporated at 60°C.

Exemplary Compound A-115g Solvent Acetone 1000g As shown in FIG. 1, the toner supply member 4 was placed in a developing device comprising a toner transport member 2 and a toner layer thickness regulating member 3. To explain the developing method using this developing device, as shown in the figure, the toner 6 contained in the toner tank 7 is forcibly brought to the toner supply member 4 by the stirring blade 5, and the toner is transferred to the toner supply member 4. is supplied to As the toner supply member rotates in the direction of the arrow, the toner taken into the toner supply member 4 is transported to the toner conveyance member 2, where it is rubbed and electrostatically or physically attracted to the toner conveyance member 2. It rotates strongly in the direction of the arrow, and a uniform thin layer of toner is formed by the toner layer thickness regulating member 3, and is charged by friction. Thereafter, the toner is transported to the surface of the latent image carrier 1 that is in contact with or in close proximity to the toner transport member 2, and the latent image is developed.

In this embodiment, the toner is supplied to the developing device, a bias of -200 V is applied to the toner conveying member, and a bias of -100 V is applied to the toner supply member to develop the negative latent image on the photoreceptor, and the image is developed through the transfer and fixing process. When the image was taken, a clear image was obtained. Subsequently, when so many copies were made successively, the same clear images as the initial ones were obtained.

In addition, the specific charge amount (Q/M) of the toner on the toner conveying member
A Faraday cage with a filter on the outlet side (
Measurements were made using a suction-type specific charge measuring device that sucks the toner on the toner conveying member and measures the specific charge of the toner trapped in the Faraday cage.

+10.5 (μC/g), which is a sufficient specific charge amount, and s
Q/M after continuous copying of o, ooo sheets is +9.7 (μC/g
) remained almost unchanged from the beginning. Furthermore, 35
℃・90%RH high temperature and high humidity, and 10℃・15%RH
Image quality equivalent to that at room temperature and humidity was obtained even in a low-temperature, low-humidity environment.

In addition, when we investigated the triboelectricity of the toner and the coating liquid coated on the surface of a metal plate using the toner suction type specific charge measuring device described above, we found that the coating liquid was coated with the toner. The coating applied to the surface of the metal plate was negatively charged.

Example 2 Carbon black (#44 manufactured by Mitsubishi Carbon Corporation)
10 parts by weight low molecular weight polypropylene
5 parts by weight quaternary ammonium salt
5 parts by weight A toner was made from the mixture having the above composition in the same manner as in Example 1.0.0 parts by weight of colloidal silica (R-972 manufactured by Nippon Aerosil Co., Ltd.) was added to 100 parts by weight of toner.
1 part by weight was added.

Next, the following composition was prepared using a ball mill at room temperature for 10 minutes.
A toner supplying member made of a conductive sponge material was immersed in the coating solution obtained by time-dispersed dissolution, and the solvent was completely evaporated at 60°C.

Exemplary compound A-2 + acrylic resin 10+20 g Solvent acetone 1000 g The toner supply member 4 was placed in the developing device in the same manner as in Example 1. The toner was supplied to the developing device, a bias of -300 V was applied to the toner conveying member, and a bias of -200 V was applied to the toner supply member, and development was carried out in the same manner as in Example 1. When an image was produced, a clear image was obtained. . Subsequently, when 50,000 sheets were continuously copied, the same clear images as the initial images were obtained. In addition, the specific charge amount (Q
/M) is sufficient at the initial stage of +8.8 (μC/g), and Q/M after 50,000 sheets of continuous copying is +8.5 (μC/g).
/g), which was almost unchanged from the initial stage. Furthermore,
Under high temperature and high humidity conditions of 35℃ and 90% RH, and 10℃ and 15%
Even in the low temperature, low humidity environment of RH, image quality equivalent to that at normal temperature and room temperature was obtained.

In addition, when we investigated the triboelectricity of the toner and the coating liquid coated on the surface of a metal plate using the toner suction type specific charge measuring device described above, we found that the coating liquid was coated with the toner. The coating applied to the surface of the metal plate was negatively charged.

Example 3 Carbon black (#44 manufactured by Mitsubishi Carbon Corporation)
12 parts by weight low molecular weight polypropylene
5 parts by weight Nigrosine dye
3 parts by weight 0.1 part by weight of colloidal silica (R-972 manufactured by Nippon Aerosil Co., Ltd.) was added to 100 parts by weight of each toner prepared by using the mixture having the above composition as a toner in the same manner as in Example 1.

Next, the following composition was prepared using a ball mill at room temperature for 10 minutes.
A toner supply member made of a sponge-like material was immersed in the coating solution obtained by time-dispersed dissolution, and the solvent was completely evaporated at 50°C.

Exemplary Compound A-520g Solvent Acetone 1000g The toner supply member 4 was placed in the developing device in the same manner as in Example 1. The toner is supplied to the developing device, and the toner conveying member is supplied with -450V.
When a bias of -100V was applied to the toner supply member and development was performed in the same manner as in Example 1, one image was produced.
A clear image was obtained. Subsequently, when so many copies were made successively, the same clear images as the initial ones were obtained. Further, the specific charge amount (Q/M) of the toner on the toner conveying member is initially +8.2 (μC/g), which is sufficient, so, oo
The Q/M after continuous copying of o sheets was +7.5 (μC/g), which was almost the same as the initial value.
Even under a high temperature and high humidity environment of 0% RH and a low temperature and low humidity environment of 10° C.-15% RH, image quality equivalent to that at room temperature was obtained.

In addition, when we investigated the triboelectricity of the toner and the coating liquid coated on the surface of a metal plate using the toner suction type specific charge measuring device described above, we found that the coating liquid was coated with the toner. The coating applied to the surface of the metal plate was negatively charged.

Comparative Example 1 When images were produced using the same apparatus and toner as in Example 1, except that the exemplified compound A-1 of Example 1 was not used as the coating material for the toner supply member 4, continuous copying 1 was obtained from the initial stage.
Clear images were obtained up to 0,000 images, but after 20
After ,000 sheets, the image density begins to decrease, so, o
After 00 sheets, the image density further decreased, afterimages, etc. occurred, and a uniform thin layer of toner was not formed on the toner conveying member.

Also, as in Example 1, the Q of the toner on the toner conveying member was
/M was measured and initially was +11°2 (μC/g)
, +4.8 (μC/g) after 20,000 sheets, so
, after ooo sheets, it was +1.5 (μC/g).

Comparative Example 2 The same apparatus and toner as in Example 1 were used except that the quaternary ammonium salt used in the toner of Example 2 was used as the coating material of the toner supply member 4 instead of the exemplified compound A-1 of Example 1. When I output the image, continuous copying 1 started from the beginning.
Clear images were obtained up to ,000 images, but 1,000 images were obtained.
After 500 sheets, the image density began to decrease, and after 2,000 sheets, the image density further decreased, afterimages, etc. occurred, and a uniform thin layer of toner was not formed on the toner conveying member.

Also, as in Example 1, the Q of the toner on the toner conveying member was
When /M was measured, the initial value was +9°5 (μC/g),
It was +2.5 (μC/g) after 1,500 sheets and +0.4 (μC/g) after 2°,000 sheets.

Comparative Example 3 Using the same apparatus and toner as in Example 1 and applying a bias of -250V to the toner conveying member and -300V to the toner supply member, similar image production was performed. A clear image was obtained up to 000 sheets, but after 20,000 sheets, the image density began to decrease, and after so and ooo sheets, the image density further decreased, and afterimages etc. occurred, causing the toner to be transported on the toner conveying member. A uniform thin toner layer was not formed on the toner, and toner filming occurred on the surfaces of the toner layer thickness regulating member and the toner conveying member.

Also, as in Example 1, the Q of the toner on the toner conveying member was
/M was measured and initially was +11°3 (μC/g)
, +5.7 (μC/g) after 20,000 sheets, so,
After ooo sheets, it was +2.6 (μC/g).

Example 4 Exemplified compound A-1 in place of Exemplified compound A-1 of Example 1
The same equipment and toner as in Example 1 were used except that No. 3 was used as the covering material for the toner supply member 4, and a bias of -350 V was applied to the toner conveying member, and a bias of -200 V was applied to the toner supply member. When developed and one image was produced, a clear image was obtained. When I continued to make so many copies, I was able to obtain clear images that were the same as the initial ones. Also, the specific charge of toss on the toner conveying member: l
(Q/M) is initially +7.3 (μC/g), which is sufficient, and after continuous copying of so, ooo sheets, Q/M is +6.7 (μC/g).
C/g), which was almost unchanged from the initial stage. Furthermore, under high temperature and high humidity conditions of 35°C and 90% RH, and at 10°C and 15%
Even under a low temperature, low humidity environment of %RH, image quality equivalent to that under normal temperature and normal humidity was obtained.

In addition, when we investigated the triboelectricity of the toner and the coating liquid coated on the surface of a metal plate using the toner suction type specific charge measuring device described above, we found that the coating liquid was coated with the toner. The coating applied to the surface of the metal plate was negatively charged.

Example 5 Exemplified compound A-2 in place of Exemplified compound A-2 of Example 2
The same equipment and toner as in Example 2 were used except that No. 8 was used as the covering material for the toner supply member 4, and a bias of -300 V was applied to the toner conveying member, and a bias of -150 V was applied to the toner supply member. When developed and imaged, a clear image was obtained. When I continued to make so many copies, I was able to obtain clear images that were the same as the initial ones. In addition, the specific charge amount of the toner on the toner transport member (
07M) is sufficient at initial +7.8 (μC/g),
Q/M after continuous copying of 50,000 sheets is +7.2 (μC/
g) was almost unchanged from the initial stage. Furthermore, 3
Under high temperature and high humidity conditions of 5℃ and 90%RH, and 10℃ and 15%R
Even in the low temperature, low humidity environment of H, image quality equivalent to that at normal temperature and room temperature was obtained.

In addition, when we investigated the triboelectricity of the toner and the coating liquid coated on the surface of a metal plate using the toner suction type specific charge measuring device described above, we found that the coating liquid was coated with the toner. The coating applied to the surface of the metal plate was negatively charged.

Example 6 Exemplified compound A-2 in place of Exemplified compound A-2 of Example 2
6 was used as the covering material for the toner supply member 4, the same equipment and toner as in Example 2 were used, a bias of -400 V was applied to the toner conveying member, a bias of -200 V was applied to the toner supply member, and the same procedure as in Example 2 was carried out. When developed and imaged, a clear image was obtained. Continue so, ooo
When I made continuous copies, I was able to obtain clear images just like the initial one. In addition, the specific charge amount (07M) of the toner on the toner conveying member is sufficient at +9.1 (μC/g) at the initial stage, and Q/M after continuous copying of so, ooo sheets is +8.6 (μC/g).
/g), which was almost unchanged from the initial stage. Furthermore,
35℃・90%RH high temperature and high humidity, and 10℃-15%
Even in the low temperature, low humidity environment of RH, image quality equivalent to that at normal temperature and room temperature was obtained.

In addition, when we investigated the triboelectricity of the toner and the coating liquid coated on the surface of a metal plate using the toner suction type specific charge measuring device described above, we found that the coating liquid was coated with the toner. The coating applied to the surface of the metal plate was negatively charged.

Example 7 Exemplified compound A-1 in place of Exemplified compound A-1 of Example 1
Using the same apparatus and toner as in Example 1, except that No. 10 was used as the covering material for the toner supply member 4, a bias of -300V was applied to the toner conveying member, and a bias of -200V was applied to the toner supply member, and development was carried out in the same manner as in Example 1. When the image was taken out, a clear image was obtained. Followed by so and oo
When o sheets were continuously copied, clear images that were the same as the initial images were obtained. In addition, the specific charge amount (07M) of the toner on the toner conveying member is sufficient at +10.1 (μC/g) at the initial stage, and after continuous copying of so, ooo sheets, 07M is +9.
3 (μC/g), which was almost the same as the initial value. Furthermore, under high temperature and high humidity conditions of 35°C and 90% RH, and at 10°C.
- Even in a low temperature, low humidity environment of 15% RH, image quality equivalent to that at room temperature and humidity was obtained. In addition, when we investigated the triboelectricity of the toner and the coating liquid coated on the surface of a metal plate using the toner suction type specific charge measuring device described above, we found that the coating liquid was coated with the toner. The coating applied to the surface of the metal plate was negatively charged.

Example 8 Exemplified compound A-2 in place of Exemplified compound A-2 of Example 2
The same equipment and toner as in Example 1 were used except that No. 1 was used as the covering material for the toner supply member 4, and a bias of -250 V was applied to the toner conveying member, and a bias of -100 V was applied to the toner supply member. When developed and imaged, a clear image was obtained. When I continued to make so many copies, I was able to obtain clear images that were the same as the initial ones. In addition, the specific charge amount of the toner on the toner transport member (
07M) is sufficient at the initial stage of +10.4 (μC/g), and after continuous copying of 50,000 sheets, Q/M is +9.5 (μC/g).
/g), which was almost unchanged from the initial stage. Furthermore,
Under high temperature and high humidity conditions of 35℃ and 90% RH, and 10℃ and 15%
R) (Even under the low temperature and low humidity environment, image quality equivalent to that under normal temperature and normal humidity was obtained.

In addition, when we investigated the triboelectricity of the toner and the coating liquid coated on the surface of a metal plate using the toner suction type specific charge measuring device described above, we found that the coating liquid was coated with the toner. The coating applied to the surface of the metal plate was negatively charged.

〔effect〕

According to the improved developing device of the present invention, the positively charged toner in the toner tank of the developing section can be smoothly replenished to the toner supply member, and at the same time there is a movement to assist the frictional charging of the toner. By applying a positive bias to the toner supply member from the toner transport member, toner can be smoothly replenished onto the toner transport member without the toner remaining on the toner supply member, and the toner flows smoothly in the developing section. As a result, the thickness of the toner layer on the toner conveying member can always be kept uniform, and as a result, good images can be obtained even after continuous copying.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the developing device of the present invention. 1... Electrostatic latent image carrier 2... Toner conveying member 3.
...Elastic blade 4...Toner supply member 5...
Stirring blade 6...Toner 7...Toner tank

Claims (1)

[Scope of Claims] 1. A toner supplying member having at least a toner transporting member and a toner layer thickness regulating member, the toner supplying member being rotatably supported while in contact with the toner transporting member and supplying toner onto the transporting member. In the developing device, at least the surface of the toner supply member has the following general formula, ▲ mathematical formula, chemical formula, table, etc. ▼ (However, R_1, R_2: H, lower alkyl group of C_1 to C_1_0, NH_2, alkylamino group A developing device characterized in that it is double coated with a composition containing at least one compound selected from the following: Zn, Co, Ni, Fe, Ten:M valence. 2. The toner supply member has a 0.0
2. The positively chargeable toner developing device according to claim 1, further comprising means for applying a positive potential bias of ~500V.