JPS61184571A - Developing device - Google Patents

Abstract

PURPOSE:To generate fine pores by subjecting a developer holding member consisting of aluminum or aluminum alloy or nonmagnetic stainless steel contg. internally a magnetic field generating mechanism to DC electrolytic etching in an acidic soln. CONSTITUTION:Dissolution is considerably nonuniform if an environmental oxidizing agent and halogen ions exist in the acidic soln. in aluminum, aluminum alloy or stainless steel. There is a tendency to the progression from nonuniform corrosion to overall dissolution when the concn. of the halogen ions increases to >=10mol/l. The nonuniform corrosion progresses hardly at the low liquid temp. and >=60 deg.C is practicable. The influence of electrolytic current density is such that the density of the pores indicates a peak at certain current density and the pore size increases gradually thereafter. The circuit for electrolytic etching is constituted by disposing a counter electrode 2 to a member to be subjected to the surface treatment so as to face said member, connecting the electrodes through an external power source 3 and dipping the electrodes into the aq. acidic soln. 4 having electrical conductivity.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applied to the surface of aluminum, aluminum alloy, or non-magnetic stainless steel used as a developer holding member (hereinafter referred to as sleeve) used in a developing device for a copying machine. It is related to processing.

BACKGROUND OF THE INVENTION A roller made of a magnetic material 3 as shown in FIG. 2 attracts the developer onto the sleeve 1 shown in FIG.

Here, the developer is conveyed by the rotation of the sleeve 1 to a position facing the photoreceptor 4, which is a type of latent image holder. Generally, the surface of the sleeve is made of a finely textured surface free from foreign matter in order to improve the conveying ability. Therefore, conventional surface treatment methods utilize mechanical external force to achieve the above-mentioned fine irregularities, such as the sandblasting method in which fine fixed or irregularly shaped hard particles are sprayed onto the sleeve member (for example, (Japanese Unexamined Patent Publication No. 58-57163) and a method of polishing with a whetstone or sandpaper (Japanese Patent Application Laid-open No. 56-57
113172) has been proposed. By adopting these methods, the pitch of the irregularities on the sleeve surface can be set to a surface roughness of 2 to 50 μm, 1 average roughness d = 0.1 to 8 μm, which is effective in improving the conveyance of the developer, and provides stable images over a long period of time. It is stated that it can be done.

Problems to be Solved by the Invention However, in the above mechanical surface treatment method, there is a high possibility that the fine hard particles used during the treatment remain attached to the surface of the sleeve material. If the sleeve material to which the hard fine particles are attached is used as a developing device, there are the following dangers.

In the developing process, the developer is attracted to the sleeve 1 by a magnet 3 called a mag roll shown in Fig. 2, and as the sleeve 1 rotates, the developer is conveyed to a position facing the photoreceptor 4 while the amount is regulated by a blade 2. . When the sleeve reaches this position, the electrostatic force of the latent image on the surface of the photoreceptor 4 causes the developer on the sleeve to move toward the photoreceptor. At this time, if the hard fine particles remain on the sleeve, there is a risk that they will fall off due to friction with the developer and move to the photoreceptor along with the developer, damaging or deteriorating it.

Means for Solving the Problems In view of the above-mentioned problems, the present invention provides a developing device using a surface treatment method that eliminates the residual of the fine hard particles. It is known that corrosion of certain metals progresses in a locally concentrated manner under certain environments. Therefore, by creating chemically non-uniform dissolution, it is possible to realize a surface treatment method in which the fine hard particles do not remain. In aluminum, aluminum alloys, or stainless steel, when an environmental oxidizing agent and nitrogen ions are present in an acidic solution, the above-mentioned non-uniform dissolution is significant. At this time, when the concentration of halogen ions exceeds 1 mmol/R, there is a tendency for uneven corrosion to progress to complete dissolution. Furthermore, if the liquid temperature is low, uneven corrosion is difficult to proceed, and a temperature of 60° C. or higher is practical. Further, as for the influence of the electrolytic current density, the pore density peaks at a certain current density, and thereafter the pore diameter gradually becomes coarser.

The pore diameter is approximately 0.8 μm at its smallest, which is well within the practical range. Therefore, an electrolytic etching circuit was constructed by immersing the surface treatment member in an acidic solution containing appropriate amounts of the above-mentioned halogen and environmental oxidizing agent, and connecting it to a counter electrode present in the same solution through an external power source.

Function The present invention supplies current from an external power source to the above-mentioned constituent circuit to dissolve the surface of the surface-treated member, which is an anode electrode, into a desired shape. The presence of grain boundaries, dislocations, segregation, and inclusions on the surface of metals and metals.

It inherently has microscopic chemical heterogeneity due to the presence of intermetallic compounds. Therefore, this is utilized to selectively dissolve chemically unstable portions on the surface to generate and grow pores.

Example (Example 1) FIG. 1 shows the surface treatment method according to the invention.

In Fig. 1, 1 is a member to be subjected to surface treatment, and a counter electrode 2 is placed facing it, connected through an external power source 3, and immersed in a conductive acidic aqueous solution to form an electrolytic etching circuit. are doing. A constant DC current is supplied from an external power source 3, the solution is stirred by a stirrer 5, and the temperature of the solution is controlled by a mantle heater 6.

First, FIG. 3 shows the relationship between electrolytic current density, pore diameter, and diameter density. At a current density of 0.4 to 0.7 A/al, the pore diameter becomes the smallest and the pore density becomes the largest. This value was calculated from capacitance measurements assuming that after electrolytic etching, a chemical conversion treatment was performed at 2 ov to obtain a single pore size distribution. Note that aluminum foil was used as the surface treated member.

(Example 2) The influence of chlorine ions added to the electrolytic solution was investigated using the same circuit configuration as in FIG. 1 and using aluminum foil as the surface treatment member.

Changes in the amount of chlorine ion added were regulated by the amount of lithium chloride added. The relationship between the pore diameter and chlorine concentration at this time is expressed as
As shown in the figure. We also investigated the effect of adding a certain amount of salt. What can be seen from this figure is that (') Chlorine 447 exceeds 3 to 4°1/l and the diameter is
The pore size is made finer by the addition of 0(2) sulfur sulfate, which causes significant coarsening and intense surface dissolution.

In addition, as the liquid temperature increases, the pore diameter becomes finer.

By using a surface treatment method that has more effects than those of the present invention, it is possible to provide a sleeve that has the same surface roughness as that obtained by the conventional sandblasting method and is free from the risk of hard particles remaining. In addition, this surface treatment method is advantageous for metal materials in which many active points are dispersed on the surface, and is particularly effective for members such as those with fine crystal grains.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the configuration of electrolytic etching as an embodiment of the present invention, Fig. 2 is a cross-sectional view of a conventional developing device, and Fig. 3 is a diagram showing the electrolytic current density and the diameter and density of etching holes. ,
Figure 4 shows the amount of chlorine ions and pores!・60 surface 3I! ! - Logic component 2... vs. 棧8... Tato # party source 1 figure 496. Enemies 1, good and bad 5..., slur 7... peak - Figure 2 7. , 21/-7'・20
．． Flute 3... Solve figure 3 of the mag bar. 4 Ah? ' 4th picture

Claims (4)

[Claims] (1) In a developing device installed facing a member that holds a latent image on its surface, a developer holding member made of aluminum, aluminum alloy, or non-magnetic stainless steel and containing a magnetic field generating mechanism inside is placed in an acidic solution. A developing device featuring a surface treatment method that generates fine pores by direct current electrolytic etching. (2) Acidic solution has a pH of -2~5 and a liquid temperature of 30℃~100.
2. The developing device according to claim 1, wherein electrolytic etching is performed at a current density of 10 A/cm^3 or less in the range of .degree. (3) Environmental oxidants such as nitric acid, hydrogen peroxide, perchlorates, dichromates, permanganates, oxygen, etc. in an acidic solution;
The developing device according to claim 1 or 2, characterized in that one or more of sulfuric acid or its salts, and ferric chloride are added in a range of 10^-^3 to 10 mol/l. . (4) One or more types of aggressive anions such as halogens or halogen groups in an acidic solution, 10^-^3 to 1
3. The developing device according to claim 1, 2, or 3, wherein the additive is added in a concentration range of 0 mol/l.