JP3105086B2 - Method for manufacturing toner carrier comprising conductive film in which dielectric material is dispersed and mixed - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel method for producing a toner carrier comprising a conductive film in which dielectric materials are dispersed and mixed for use in an electrophotographic apparatus or the like.

[0002]

2. Description of the Related Art In a device utilizing an electrophotographic method, particularly a device such as a copying machine, a printer or a facsimile, a two-component developer containing a toner and a carrier is used as a developing device for developing an electrostatic latent image. There are an apparatus configured to attract the magnetic carrier and transport it to the development area, and an apparatus configured to transport the one-component toner to the development area by the toner carrier. Among them, the method using one-component toner
There is an advantage that not only the device can be downsized, but also the maintenance of the device is easy.

In a developing device using such a one-component toner, it is necessary to supply a sufficient amount of toner to uniformly develop the latent image on the surface of the photoreceptor. Therefore, a number of minute closed electric fields are formed in the vicinity of the surface of the toner carrier that carries the toner by, for example, contact charging, and a large amount of toner is adhered and carried on the surface of the toner carrier by the action of the closed electric field. There is. Such a toner carrier having a large number of minute closed electric fields formed in the vicinity of the surface, for example, a structure in which a conductive powder and a dielectric resin powder are mixed on a conductive support, electrostatically coated, and fused. However, this has the problem that the ratio between the conductive powder and the dielectric resin powder tends to change due to fluctuations in the applied voltage during electrostatic coating, making it difficult to stabilize the quality. There is a disadvantage that it is difficult to obtain a smooth and uniform surface layer due to a difference in melting point and a difference in thermal expansion from the resin powder.

Instead of providing a surface layer as described above, a toner carrier having a structure in which fine grooves are provided vertically and horizontally on the surface of a conductive support and these grooves are filled with a dielectric material (Japanese Patent Laid-Open No. 4-468). No. 2) has been proposed, but it requires the formation of grooves in the support and the polishing and smoothing after filling the dielectric material, which has the disadvantage of complicating the process and increasing the cost.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the fact that the conventional toner carrier in which a large number of minute closed electric fields are formed in the vicinity of the surface has problems in quality and manufacturing process. The present invention is intended to provide a novel "method of manufacturing a toner carrier comprising a conductive film in which dielectric materials are dispersed and mixed" in which a uniform and smooth conductive surface layer in which dielectric materials are dispersed and mixed is formed on a support. This is intended to obtain a toner carrier having stable quality and easy production.

[0006]

According to the first aspect of the present invention, there is provided a heat-meltable dielectric material, comprising: a crystalline material having a conductive phase and a crystalline phase having an amorphous phase. Forming a dispersion mixed layer of an amorphous semiconductor material having a lower crystallization temperature than the melting point of the dielectric material on a support, and then heat-treating the layer at a temperature higher than the melting point of the dielectric material to melt and smooth the layer; Further, a toner carrier comprising a conductive film in which a dielectric material is dispersed and mixed, wherein a heat treatment is performed at a temperature higher than a crystallization temperature and lower than a melting point of the dielectric material to convert the semiconductor material into a crystalline phase to make the material conductive. It is a method of manufacturing the body.

According to a second aspect of the present invention, in the first aspect of the invention, the amorphous material is selected from one or more elements belonging to 3B or 6B of the periodic table (1985). It is a selected material.

According to a third aspect of the present invention, in the first or second aspect, the dispersion / mixing layer is formed on a support by electrostatic coating.

According to a fourth aspect of the present invention, in the first or second aspect of the invention, the dispersion / mixing layer is formed on a support by electrostatic coating.

As the heat-fusible dielectric material used in the present invention, for example, an aliphatic polyamide resin or an aromatic polyamide resin is preferably used, but it is not particularly limited to these synthetic resins.

As a semiconductor material comprising one or more elements belonging to 3B or 6B of the periodic table of elements (1985) used in the present invention, for example, chalcogen or chalcogenide compounds are preferably used. It is necessary to select one in which the crystalline phase is non-conductive, the crystalline phase is conductive, and the crystallization temperature of the amorphous phase is lower than the melting point of the dielectric material. Periodic Table of the Elements (198
5 years) is published by Maruzen Co., Ltd. on October 15, 1986.
It is generally well-known, as described in the “Periodic Table of Elements (1985)” on the back cover side. The melting point of the semiconductor material is preferably higher than the melting point of the dielectric material, but is not particularly limited.

In forming a conductive film in which a dielectric material is finely dispersed and mixed on a support according to the present invention, a powdery mixture of the respective materials or a powder obtained by coating the surface of a semiconductor material powder with a dielectric material. A method of electrostatically applying a composition or the like to the surface of a support, a method of simultaneously vacuum-depositing each material on the surface of the support, or a fiber obtained by coating the surface of a fibrous semiconductor material with a dielectric material An appropriate method such as a method of thermally fusing a woven or nonwoven fabric to the surface of the support can be used.

[0013]

The conductive film formed on the support by the method of the present invention and in which the dielectric material is finely dispersed and mixed is a semiconductor comprising at least one element belonging to 3B or 6B of the periodic table of elements (1985). Since the material is non-conductive in the amorphous phase and conductive in the crystalline phase, when performing electrostatic coating, the non-conductive amorphous phase semiconductor material is powdered in the same manner as the dielectric material, By mixing and using the powder of the dielectric material, a dispersion layer having a uniform composition can be easily formed on the support. By heating to a temperature higher than the crystallization temperature of the semiconductor material, the material is converted into a conductive state by crystallization, and at the same time, heat is generated to promote the melting of the dielectric material. A film is formed.

Further, since such a semiconductor material can be relatively easily vacuum-deposited to form an amorphous-phase deposited layer, it can be simultaneously deposited with a dielectric material such as a synthetic resin. The layer formed by co-evaporation is a dispersed film having a uniform thickness and composition, and the amorphous phase in the film is easily crystallized by heating to a temperature higher than the crystallization temperature to become conductive. Further, even when the dispersion-mixed film is formed by another method, a film in which the semiconductor material and the dielectric material are finely dispersed and mixed can be easily obtained in the same manner as described above.

[0015]

EXAMPLES (First Example) Amorphous selenium powder having a purity of 99.999% and pulverized to an average particle size of 100 μm (crystallization temperature: 180 ° C., melting point: 217)
C) 70 parts by weight and 30 parts by weight of powdered nylon 12 (Nippon Rilsan, Orgasol 2002 ES-5 NAT, melting point: 175 ° C.) with an average particle size of about 50 μm are uniformly mixed, and a cylindrical aluminum alloy support is used. Electrostatic coating was performed on the body to form a layer having an average thickness of 100 μm. Next, this was heat-treated at 220 ° C., baked, cooled once, and then heated to 150 to 200 ° C. to obtain a film having good adhesion with a surface roughness Rz of 10 μm or less. This film had a thickness of 90 μm, in which nylon 12 and crystalline selenium were uniformly dispersed and mixed. When the conductivity was measured, a specific resistance value of 1 × 10 ⁶ Ωcm was obtained.

Second Example Amorphous selenium-tellurium alloy powder containing 20% by weight of tellurium pulverized to an average particle diameter of 100 μm (crystallization temperature 160
70 ° C., average particle size 100 μm
And 30 parts by weight of powdered nylon 6 (Unitika, A1030BRF, melting point: 180 ° C.) were uniformly mixed, and electrostatically coated on a cylindrical support in the same manner as in the first embodiment to obtain an average film thickness of 100 μm. Was formed. Then add this to about 200
The film was rotated and fused while being pressed against a roller heated to ° C., to obtain a film having properties similar to those of the first example.

(Third Embodiment) A melt of a selenium-tellurium alloy containing 50% by weight of tellurium (crystallization temperature: 120 ° C., melting point: 280 ° C.) is stretched at 350 ° C. while being extruded from a nozzle and stretched to a diameter of 20 μm. A crystalline fiber was formed, and after cooling, the same nylon 12 used in the first example was dissolved in meta-cresol and passed through a dope. Then, the solvent was removed to form a nylon-coated alloy fiber having a diameter of 50 μm. Next, a yarn obtained by twisting 20 of these fibers is woven in a tubular weave and put on a cylindrical support, and further, a PFA heat-shrinkable tube (manufactured by Gunze) is put on the outside of the cylindrical support.
After heating to 0 ° C. for 1 minute to fuse to the support and cooling, the PFA tube was removed. The film thus obtained was sufficiently smooth and the exposure distribution of the semiconductor material was uniform.

Fourth Embodiment A cylindrical support is provided in a vacuum evaporation apparatus, 70 parts by weight of selenium having a purity of 99.999% is provided in a first evaporator, and a second example is provided in a second evaporator. 30 parts by weight of the same nylon 6 as used in the above was charged, and simultaneously deposited on a support kept at a temperature of 60 ° C. at a degree of vacuum of 10 ⁻⁴ Torr, and further heat-treated at 200 ° C. for 30 minutes to form a 50 μm thick film. A smooth film was obtained. This film had properties similar to those of the first embodiment.

[0019]

According to the method of the present invention for producing a toner carrier comprising a conductive film in which a dielectric material is dispersed and mixed, the dispersion of the dielectric material and the semiconductor material is uniform and the surface is smooth. A toner carrier composed of a film having good conductivity can be easily formed on a support. And when the support is a metal, it has the feature that the adhesion of the film is excellent,
This has the effect of stably producing a contact charging type toner carrying roller for electrophotography having a uniform toner carrying density and excellent durability.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G03G 13/08-13/095 G03G 15/08-15/095

Claims (4)

(57) [Claims] A dispersion mixed layer of a heat-meltable dielectric material and an amorphous semiconductor material in which a crystalline phase is conductive and an amorphous phase has a crystallization temperature lower than a melting point of the dielectric material. Is formed on a support, and then the layer is heat-treated at a temperature higher than the melting point of the dielectric material to be melt-smoothed, and further heat-treated at a temperature equal to or higher than the crystallization temperature and lower than the melting point of the dielectric material to form a semiconductor material. A method for producing a toner carrier comprising a conductive film in which a dielectric material is dispersed and mixed, wherein the toner carrier is converted into a crystalline phase and made conductive. 2. The method according to claim 1, wherein the amorphous material has a periodic table of elements (19).
The toner carrier comprising a conductive film in which a dielectric material is dispersed and mixed according to claim 1, wherein the toner carrier is a material selected from one or more elements belonging to 3B or 6B (1985). Manufacturing method. 3. The method according to claim 1, wherein the dispersion mixed layer is applied to a support by electrostatic coating.
3. The method according to claim 1, wherein
Toner carrier made of conductive film in which dielectric material is dispersed and mixed
Manufacturing method. 4. The method according to claim 1, wherein the dispersion mixed layer is vacuum-deposited on a support.
3. The method according to claim 1, wherein
Toner carrier made of conductive film in which dielectric material is dispersed and mixed
Manufacturing method.