JPS61250200A - Production of developer holding member - Google Patents

Abstract

PURPOSE:To produce an adequate developer holding member by subjecting a non-magnetic material to AC electrolytic etching at an optional frequency in an acidic soln. to form fine pores on the surface thereof and using such metal as a sleeve for a developing device. CONSTITUTION:The developer holding member 7 to be subjected to the etching treatment and a counter electrode 8 are immersed into an acidic soln. 6 (2-6pH) consisting of a hydrochloric acid and sulfuric acid compounded at a prescribed ratio and are connected to an external power source 9. Oxygen is substantially satd. in the soln. 6 and thereafter the liquid temp. is kept at 30-100 deg.C by a heater 11. AC current or pulse current is impressed from the power source to the member and electrode at <=50A/dm<2>, by which the surface of the developer holding member is etched. The developer holding member which has the surface roughness equiv. to the surface roughness by a mechanical surface treatment method and on the surface of which a fine polishing agent, etc., do not exist at all is thus obtd.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for manufacturing a developer holding member used in a developing device for a copying machine, and more specifically, to a method for manufacturing a developer holding member called a sleeve. The present invention relates to surface treatment of a developer holding member made of aluminum, aluminum alloy, nonmagnetic stainless steel, or the like.

(Prior Art) First, the structure of a general developing device of a copying machine will be explained with reference to FIG. In the figure, the developing device of the copying machine is
A position on the outer periphery of a magnet roll 2 made of a magnetic material that rotates counterclockwise so as to face the photoreceptor 1 holding a latent image due to an electric charge, so as to place the developer 3 at a position facing the photoreceptor 1. A sleeve 4 is disposed to convey the developer, and a blade 5 is further disposed at the outlet of the sleeve 4 to regulate the thickness of the developer sucked onto the surface of the sleeve 4.

The sleeve 4 of such a developing device has fine irregularities formed on its surface so as to have a high developer transporting ability.

The surface finishing of the developer holding member used in the sleeve 4 was done by a mechanical working method. A sandblasting method (for example, Japanese Patent Application Laid-Open No. 5-11311) involves spraying fixed or irregularly shaped hard particles with a particle size within a certain range in order to obtain an appropriate surface roughness.
8-58163), or a method of polishing with a grindstone or sandpaper (Japanese Patent Application Laid-open No. 113172/1982). With these methods, the pitch can be reduced to 2μ.
diameter to 50μm, average diameter 0.1μm to 10μm
It is said that improved and stable image quality can be obtained over a long period of time by creating a surface with irregularities, improving and stabilizing the developer conveying force.

(Problems to be Solved by the Invention) However, in the surface treatment using the above mechanical working method, hard particles or abrasives used during the treatment remain attached to the surface of the developer holding member.

There is a very high possibility that it remains on the surface of the sleeve 4 molded using this.

In a developing device using such a sleeve 4, the developer 3 conveyed on the surface of the sleeve 4 has a uniform adhesion thickness by the blade 5, and is deposited on the surface of the photoreceptor 1 at a position facing the photoreceptor 1. Fine hard particles or abrasives remaining on the surface of the sleeve 4 when moving to the photoreceptor 1 due to the electrostatic force caused by the charge of the formed latent image fall off due to contact and friction with the developer 3, and are removed together with the developer 3. There is a high risk of the particles migrating to the photoreceptor 1, damaging the photoreceptor 1, and deteriorating its performance.

The present invention solves the above problems and provides a method for surface treatment of a developer holding member to obtain a sleeve in which fine hard particles or abrasives do not remain.

(Means for Solving the Problems) In order to solve the above-mentioned problems, 1. the present invention employs electrolytic etching in an acidic solution in which an environmental oxidizing agent and halogen ions coexist. The objective is to obtain surface roughness and shape.

(Function) Etching is normally used to smooth the surface; however, in the present invention, etching can chemically dissolve unevenly in an acidic solution containing an oxidizing agent and halogen ions, resulting in a rough surface. A surface similar to that obtained by mechanical surface treatment is obtained by repeating dissolution and precipitation by passing a current in a forward and reverse direction in a pulsed manner.

Since such electrochemical surface treatment does not use hard particles or abrasives, they do not remain on the surface of the developer retaining member. Also, unlike DC etching,
In addition to the magnitude of the current, the current waveform is also one of the regulating factors, which has the advantage of widening the range of selection depending on the shape of one surface.

(Example) An electrochemical surface treatment device for a developer holding member according to the present invention will be explained with reference to FIG. In the figure, after a developer holding member 7 and a counter electrode 8 to be subjected to etching treatment are immersed in an acidic solution 6 containing 10% hydrochloric acid (HCI) and 7% sulfuric acid (HtSOJo), the waveform and time of the current applied to them are shown. form a circuit by connecting to an external power supply 9 that controls the
Furthermore, a stirrer io that stirs the solution 6, and a stirrer io that stirs the solution 6,
A heater 11 is provided to raise the temperature.

The solution 6 is sufficiently saturated with oxygen, and the temperature of the solution is maintained at 45°C by the heater 11, and the temperature is 0.4A/cd as shown in FIG.
The anode current density Ia, the cathode current density Ic, and a pause were periodically repeated for a period of 10 m5 to perform surface treatment on the developer holding member 7.

FIG. 4 shows the relationship between the diameter and density of etched holes formed on the surface of the aluminum foil, which is the developer holding member 7 of this embodiment, and the cathode current density Ic, where the horizontal axis is the cathode current density A/aJ. , the vertical axis is the etching hole diameter μm and the etching hole density/μm.

As shown in the figure, as the cathode current Ic increases, the etching pore diameter decreases and, conversely, the pore density increases. Also, when the cathode current density is extremely low, it resembles a surface formed by direct current electrolytic etching.

FIGS. 2(a) and 2(b) show cross-sectional views of surfaces treated by DC electrolytic etching and pulsed electrolytic etching, respectively. As can be seen from FIG. 2(b),
Surface treatment using pulsed electrolytic etching provides surface roughness equivalent to mechanical surface treatment.

The conveying power can be improved without worrying that the developer powder will clog the holes on the surface of the sleeve.

In addition, Fig. 4 shows the pulse shape shown in Fig. 3 as it is,
This shows the relationship between the cathode current density Ic, which is a regulating element, and the etched pore diameter and pore density.
The cathode current density Ic for obtaining 0 μm is 0.2 A/ad or less.

(Effects of the Invention) According to the surface treatment method of the present invention, the surface shape is equivalent to that obtained by mechanical surface treatment, the surface roughness is suitable for use in the sleeve of a developing device, and the surface has fine hard particles or It is possible to obtain a developer holding member that does not contain any abrasive,
This has a significant effect on stabilizing the quality and improving the lifespan of copying machines equipped with this.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an electrolytic cell for surface treatment by pulse electrolytic etching according to the present invention, and FIGS. Fig. 3 is a diagram of the shape of the pulse current in the example, Fig. 4 is a diagram of the relationship between the cathode current density and the etching surface using the waveform of Fig. 3, and Fig. 5 is a cross-sectional view showing the structure of the developing device of the copying machine. . 1...Photoreceptor, 2...Magnet roll, 3...
Developer, 4...Sleeve, 5...Blade. 6... Acidic solution, 7... Developer holding member, 8...
- Counter electrode, 9... external power supply, 10... stirrer. 11... Heater, Ia... Anode current density,
Ic...Cathode current density. Figure 1 ``α ■ To 11 Figure 2 (a) (b) Figure 3 Figure 4 Figure 18fIl flowffi degree (A/cm2) 4-- per person 5-11 free hand

Claims (4)

[Claims] (1) Development characterized by forming fine pores on the surface of a non-magnetic metal by performing alternating current electrolysis at an arbitrary frequency in an acidic solution, or pulse electrolytic etching by applying a pause or reverse current at an arbitrary impact coefficient. A method for manufacturing a drug holding member. (2) A patent claim characterized in that the pH of the acidic solution is -2 to 6, the liquid temperature is in the range of 30°C to 100°C, and the applied current for both AC electrolysis and pulsed electrolytic etching is 50A/cm^2 or less A method for manufacturing a developer holding member according to item (1). (3) In the acidic solution, nitric acid, hydrogen peroxide, perchlorates,
Dichromates, permanganates, environmental oxidizing agents such as oxygen, sulfuric acid or its salts, and one or more trivalent iron ions at a concentration of 10^-^mol/l to 10mol
The method for manufacturing a developer holding member according to claim 1, wherein the amount of the developer is added in a range of 1/1. (4) Adding one or more types of aggressive anions such as halogens or halogen groups to an acidic solution at a concentration of 10^-^3
The method for manufacturing a developer holding member according to any one of claims (1) to (3), wherein the additive is added in a range of mol/l to 10 mol/l.