JP2886593B2 - Method for manufacturing developer carrier - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a developer carrier used in a developing device.

(Prior art) Conventionally, a developer carrier (sleeve) carries toner,
It works as a contact member.
As shown in JP-A-968, a resin layer and a conductive particle layer are formed on a conductive support. Each of these layers is formed by coating and surface processing.

JP-A-51-123754 proposes a method of forming a resin layer containing conductive particles by spraying a paint in which conductive particles are dispersed in a resin.

(Problems to be Solved by the Invention) However, with the improvement in image quality of electrophotography, the surface quality required of the sleeve has become higher, and it has become necessary to obtain a work relationship with a desired surface shape. In the conventional example, it was impossible to realize higher image quality.

In addition, no inexpensive and industrially superior production technical means have been found for obtaining these high surface qualities.

In particular, when spraying a substance having a difference in specific gravity or a particle size distribution, such as a pigment such as a metal particle or a solid lubricant, by spraying, a general needle type spray gun (for example, Binks 601 gun). In the case of using, there is a problem that the pigment particles are clogged in the nozzle and the paint cannot be supplied.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method of manufacturing a developer carrier (sleeve) having a high required quality by eliminating the above-mentioned disadvantages of the prior art.

(Means for Solving the Problems) The above object is achieved by the present invention described below.

That is, the present invention relates to a method for producing a development carrier in which a coating is applied to a conductive support by a spray method to form a surface layer, wherein the coating has a graphite having an average particle size of 0.5 to 10 μm;
Methyl methacrylate resin as binder resin, phenol resin, Teflon resin, polycarbonate resin, nylon resin, polyethylene resin, polystyrene resin, resin selected from the group consisting of acrylic resin and formalin resin and at least a solvent in which the binder resin is soluble A mixed solution, wherein in the above spray method, a hose is embedded so that the tip of a resin or metal hose is located at the tip of the nozzle, and a spray having no needle valve at the tip of the nozzle is used. The paint is sucked from the other end of the hose by discharging air from a peripheral hole on a concentric circle of the tip of the hose at the tip, and discharged from the tip of the hose through the hose. Atomization, the average surface roughness Ra on the conductive support is 0.3
The present invention relates to a method for producing a developer carrying member, wherein a surface layer having a thickness of about 2.5 μm is formed.

(Response) Resin The nozzle is clogged with resin paint containing a pigment such as solid lubricant by using a spray gun that discharges air from concentric circles around the nozzle where a metal hose is embedded. Spraying well, without letting
It can be atomized and painted to form a good film and form a sleeve having a desired surface shape and a desired work function.

EXAMPLES Next, the present invention will be described in more detail with reference to the examples shown in the accompanying drawings.

First, as shown in FIG. 1, a conductive support 1 is prepared. Although the illustrated support 1 has a hollow cylindrical shape, it is needless to say that the support 1 may have another shape.

When the developing device using the completed sleeve is a device using a magnetic developer, the sleeve is a non-magnetic material as is well known, and a conductive support 1 made of a non-magnetic material is prepared.

Pigments such as solid lubricants and conductive particles that can be used in the present invention, for example, graphite, molybdenum disulfide,
Conventionally known materials such as boron nitride and tungsten disulfide can be used, and are not particularly limited. In the present invention, graphite having an average particle size of at least 0.5 μm to 10 μm is used.

As the binder resin constituting the vehicle of the pigment, methyl methacrylate resin (PMMA), phenol resin, Teflon resin, polycarbonate resin, nylon resin, polyethylene resin, polystyrene resin, acrylic resin or formalin resin is used.

As a solvent for dissolving the binder resin, any conventionally known solvent such as methyl ethyl ketone (MEK), methanol, xylene, methyl cellosolve, toluene, chlorobenzene, dichloromethane, isopropyl alcohol (IPA), and butanol can be used. Yes,
There is no particular limitation.

The proportions of the pigment, the binder resin, the solvent in which the binder resin is soluble and the additives to be added as necessary may be the same as those of the conventionally known surface layer forming paint.

As an example of the coating material 3 used in the present invention, 10 parts by weight of carbon black, 90 parts by weight of graphite (average particle size: 7 μm), 100 parts by weight of PMMA resin and MEK solvent are adjusted so that each solid content shown in Table 1 below is obtained. The mixture was mixed, put into a paint shaker together with glass beads, and dispersed for 5 hours to prepare.

In such a coating material, coarse particles tend to settle with time, and thus the stirring was continued with the magnetic stirrer 4 during coating.

Next, Table 1 shows the results of each study in which coating was performed using the spray gun shown in FIGS. 2A and 2B and a conventionally known needle type air spray gun (not shown).

Incidentally, the above-mentioned paint has poor compatibility depending on the combination of the pigment, the binder resin and the solvent in which the binder resin is soluble, and the pigment may precipitate even when stirred with the stirrer 4; In the spray head 2, the coating can be performed without any problem, and the sleeve can be favorably manufactured.

As shown in Table 1 above, it can be seen that a sleeve having a desired surface roughness and work function can be obtained by using the air type spray gun used in the present invention.

In addition, when a conventional needle-type binks (601) spray gun is used, nozzle clogging occurs particularly when the solid content is high. This is caused by controlling the flow rate of the fine nozzle by finely adjusting the needle, and is a fatal drawback when the viscosity of the paint increases or a substance containing a pigment having a large particle size passes through the nozzle.

The air type spray gun used in the present invention will be described in more detail.

When adjusting the discharge amount of the paint with this spray gun, it is possible to control the flow rate of the air, the length of the hose, and the inner diameter of the hose (see FIGS. 3 to 5).

That is, in the spray gun used in the present invention, since there is no place where the flow path is restricted by the needle valve, clogging of the nozzle does not occur even if it is used for a long time, especially if a water-repellent Teflon hose is used. In principle, the hose tip is depressurized by air discharged from the concentric hole, and the paint is sucked and discharged.

The configuration of the air type spray gun used in the present invention is shown in FIGS. 2a and 2b, but it is preferable that the adjustment is performed by two types of air, air 1 and air 2.
In particular, there is a correlation with respect to the paint weight from which the air 1 is discharged, and also has a relationship as shown in FIG.

Air 2 is air required to change the atomization state of the paint, and has a relationship between the air flow rate and the sleeve surface roughness as shown in FIG. Although the present invention can be achieved without using the air 2, the use of the air 2 provides a more accurate surface state.

 Here, the surface grain size and the work relationship will be described.

The surface particle size was measured using Surf Test 101 manufactured by Mitutoyo. Since the sleeve is a toner contact member, its surface shape is important, and it is necessary that a desired roughness is always formed stably. In particular, the average surface roughness Ra is 0.3 μm or more.
It is good to be 2.5 μm, preferably 0.5 μm to 2.0 μm. In particular, as a means for controlling the surface roughness, it is possible to use a method of adjusting the particle size of the pigment (see FIG. 7) and a pattern adjusting air (see FIG. 8).

The work function was measured using a surface analyzer AC- manufactured by Riken Keiki.
1 was used. FIG. 6 shows the relationship between the difference in work function between the toner and the sleeve and the charge amount. Even if the same substance is used, the work function is different if the proportion of the pigment or binder resin distributed on the surface is different. If the difference is 0.2 to 1.2 eV, preferably 0.5 to 1.0 eV, a sufficient charge amount can be obtained.

(Effects of the Invention) According to the present invention as described above, a pigment such as a solid lubricant is used by using a spray gun that discharges air from a concentric peripheral hole of a nozzle in which a resin or metal hose is embedded. Can be sprayed and atomized without clogging the nozzle with a resin coating containing, and can be coated well to form a sleeve having a desired surface shape and a desired work function. I can do it.

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating the method of the present invention, FIG. 2 is a diagram illustrating the structure of a spray gun used in the present invention, and FIGS. FIG. 6 is a diagram illustrating the relationship between the flow rate of air, the length of the hose, and the inner diameter of the hose. FIG. 6 is a diagram illustrating the relationship between the difference in work function between the toner and the sleeve and the amount of charge, and FIG. FIG. 8 is a diagram for explaining the relationship between the roughness and the particle size of the pigment, and FIG. 8 is a diagram for explaining the relationship between the air flow rate and the sleeve surface roughness. 1: Support 2: Spray gun 3: Paint 4: Stirrer

Claims (4)

(57) [Claims] 1. A method for producing a developer carrier, in which a coating material is applied on a conductive support by a spray method to form a surface layer, the coating material comprising graphite having an average particle size of 0.5 to 10 μm and binder resin. Methyl methacrylate resin, phenol resin, Teflon resin, polycarbonate resin, nylon resin, polyethylene resin, polystyrene resin, a resin selected from the group consisting of acrylic resin and formalin resin and a mixed solution containing at least a solvent in which the binder resin is soluble. In the above spray method, a hose is embedded so that the tip of a resin or metal hose is located at the tip of the nozzle, and a spray having no needle valve is used at the tip of the nozzle. By discharging air from the surrounding hole on the concentric circle at the tip of the hose, Paint was aspirated from the other end of the hose, together with ejected from the tip of the hose through the hose, perform the atomization of the paint, the average surface roughness Ra on a conductive support is 0.3 to 2.5
A method for producing a developer carrier, comprising forming a surface layer having a thickness of μm. 2. The method for producing a developer carrier according to claim 1, wherein the agitated paint is applied by a spray method using the spray while stirring the paint. 3. The method according to claim 1, wherein the surface layer formed on the conductive support has an average surface roughness Ra of 0.5 to 2.0 μm. Method. 4. The method according to claim 1, wherein the paint is a mixed solution further containing carbon black.