JPH0344764Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a conductive roller used as a toner conveying roller, paper feeding roller, etc. of an electrophotographic copying machine.

[Conventional technology]

The toner conveyance rollers and paper feed rollers of electrophotographic copying machines are required not to be electrically charged themselves, and are usually made conductive by using a conductive agent. A typical example of this type of conductive roller is shown in the fifth example.
As shown in the figure. In the figure, reference numeral 1 is a metal shaft having rotating shafts 2 on both left and right end surfaces, and 3 is a conductive hard rubber fixed to the outer peripheral surface of the metal shaft 1 by an adhesive layer 4 containing a conductive agent. It is a layer. In the conductive roller having such a structure, static electricity on the surface of the conductive hard rubber layer 3 flows to the metal shaft body 1 via the conductive agent-containing adhesive layer 4, thereby preventing static electricity.

[Problem that the invention attempts to solve]

However, the conductive roller described above is not easy to manufacture because the conductive elastic material layer 3 such as a conductive hard rubber layer is fixed to the metal shaft body 1 with an adhesive containing a conductive agent. This method has disadvantages in that the adhesion of the conductive hard rubber layer is not very strong and the cost is high. That is, adhesives containing conductive agents have a high viscosity due to the inclusion of conductive agents such as carbon particles and metal powder, and therefore have poor workability in application, which makes it difficult to manufacture conductive rollers. In addition, the adhesive strength of the adhesive is reduced due to the conductive agent mixed in, and the adhesion of the conductive hard rubber layer 3 is not perfect.Furthermore, the cost of the adhesive is increased due to the conductive agent mixed in. However, the cost of the resulting conductive roller also increases. Moreover,
The adhesion that can be used is restricted due to the contamination of the conductive agent, resulting in a disadvantage that the degree of freedom in selecting the adhesive is reduced.

This invention was made in view of the above circumstances, and its purpose is to provide a conductive roller in which a conductive elastic material layer such as a conductive hard rubber layer is completely fixed.

[Means for solving problems]

In order to achieve the above object, the conductive roller of this invention has a metal shaft and a conductive elastic material layer formed on the outer peripheral surface of the metal shaft directly or via a conductive foam layer. At least a part of the outer circumferential surface of the metal shaft body is formed with an uneven rough surface, and the conductive foam material layer or the conductive elastic material layer is in contact with at least the top of the convex part of the uneven rough surface. , and is adhered to the outer circumferential surface of the metal shaft body with an adhesive.

In other words, in the above-mentioned conductive roller, the convex portion of the uneven rough surface formed on the outer circumferential surface of the metal shaft directly contacts the conductive elastic material layer (conductive foam material layer), and the conductive roller becomes conductive with the metal shaft. In order to establish electrical continuity between the elastic material layer and the conductive elastic material layer, it is possible to use an adhesive that does not contain a conductive agent to bond the metal shaft and the conductive elastic material layer, thereby improving workability. This makes it possible to improve the adhesion state of the conductive elastic material layer and reduce costs.

Next, examples will be explained in detail.

〔Example〕

FIG. 1 is a longitudinal sectional view of an embodiment of this invention. In the figure, reference numeral 5 denotes a metal shaft body having rotating shafts 6 on both left and right end faces, 7 a conductive elastic material layer made of hard conductive rubber fixed to the outer peripheral surface of the metal shaft body 5, and 8 a conductive elastic material layer made of the metal shaft 5. Shaft body 5 and conductive elastic material layer 7
It is an adhesive for bonding and does not contain conductive materials.
What should be noted is the metal shaft body 5, as shown in Figure 2.
The outer peripheral surface of is formed into an uneven rough surface 5a by wire brushing, and the convex tops 5b of the uneven rough surface 5a are embedded in the lower part of the conductive elastic material layer 7,
Both are in a conductive state. The conductive material-free adhesive 8 is located in the concave portion of the uneven rough surface 5a of the metal shaft 5, and exhibits an adhesion effect between the metal shaft 5 and the conductive elastic material layer 7. Such conductive agent-free adhesive 8 is usually a chlorinated rubber adhesive adjusted to a viscosity of 10 to 200 cps, and applied to the uneven rough surface 5a of the metal shaft 5 to a thickness of 1.
It is formed by coating to a thickness of ~100 μm. This adhesive layer 8 ensures the basic adhesive force between the metal shaft 5 and the conductive elastic material layer 7.

In this way, in this conductive roller, the conductive elastic material layer 7 is formed on the uneven rough surface 5a of the outer peripheral surface of the metal shaft body 5.
Because the convex part is biting in, it is in a state of conduction with the shaft 5, so as in the past, an adhesive containing a conductive agent (high viscosity, poor application workability, etc., and weak adhesive strength) is used. This eliminates the need for this, which not only improves the workability of applying the adhesive, but also makes it possible to strengthen the adhesive state of the conductive elastic material layer 7, and furthermore, it becomes possible to reduce the overall cost.

FIG. 3 shows another embodiment of this invention.

This conductive roller has an uneven rough surface 9a (see FIG. 4) formed by buffing on the outer peripheral surface of a cylindrical metal shaft 9, and a urethane foam layer 1 is formed on the outer periphery.
0 is formed along the circumference, and a conductive rubber layer 11 made of hard rubber is further formed along the circumference on the outer periphery. A conductive agent-free adhesive layer 1 is provided between the metal shaft 9 and the urethane foam layer 10.
2, and an adhesive layer 13 containing a conductive agent is formed between the urethane foam layer 10 and the conductive rubber layer 11. Reference numeral 14 denotes a conductive agent injection part injected into both left and right ends of the urethane foam layer 10 using a syringe or the like, and the urethane foam layer 1
At 0, only this portion has conductivity.

In this way, as shown in FIG. 4, in this conductive roller, the convex tops 9b of the uneven rough surface 9a formed on the outer peripheral surface of the metal shaft 9 are connected to the conductive agent injected portions 14 of the urethane foam layer 10. As a result, the metal shaft 9 and the conductive elastic material layer 11 are electrically connected through the conductive agent injection portion 14 of the urethane foam layer 10. Therefore, the urethane foam layer 10 and the metal shaft 9 are subjected to particular pressure.
It is now possible to use a conductive-free adhesive that does not contain a conductive agent as an adhesive between become.

In addition, in the embodiments of FIGS. 1 and 3,
The surface roughness of the uneven rough surfaces 5a and 9a formed on the outer peripheral surfaces of the metal shafts 5 and 9 is set so that the 10-point average roughness is about 10 to 70μ according to JIS B 0601, and Good results can be obtained by setting the thickness of the conductive agent-free adhesive layers 8, 12 coated on the rough surface within the range of 1 to 10 microns. In this case, sufficient electrical conductivity can be maintained by exposing the tops 5b, 9b of the convex portions of the uneven rough surfaces 5a, 9a when forming the conductive agent-free adhesive layers 8, 12. .
Therefore, the uneven rough surfaces 5a of the metal shafts 5 and 9,
The uneven rough surface 5a is coated with adhesive thicker than the height of the convex portion of the uneven surface 9a, and then the excess adhesive is removed by buffing or the like.
The convex tops 5b and 9b of a and 9a may be exposed. Further, the conductive elastic material layers 7, 1
The materials for the conductive foam layer 1 and the conductive foam layer 10 are not limited to those in the above embodiments, but can be appropriately selected from conventionally known materials. In addition, uneven rough surfaces 5a and 9a formed on the outer peripheral surfaces of the metal shaft bodies 5 and 9
may not be formed on the entire outer circumferential surface of the shaft bodies 5, 9, but may be formed only on a part thereof. For example, in the embodiment shown in FIG. 3, it may be formed only in the portion of the shaft body 9 corresponding to the conductive material injection portion 14. Furthermore, in this invention, good adhesion between the uneven and rough surfaces 5a and 9a is ensured, and therefore, even if an adhesive containing a conductive agent is used as the adhesive, a sufficient adhesion state can be obtained. become.

[Effect of idea]

As described above, in the conductive roller of this invention, the tops of the convex portions of the uneven rough surface formed on the outer peripheral surface of the metal shaft are embedded in the conductive elastic material layer, etc. Since the material layer and the metal shaft are electrically connected, there is no need to include a conductive agent in the adhesive that bonds the metal shaft and the conductive elastic material layer. You can now use regular adhesives. Therefore, not only is the effect of improving the workability of applying the adhesive, but also the adhesive strength of the adhesive that does not contain a conductive agent and the tops of the convex parts of the uneven rough surface are formed in the conductive elastic material layer. Due to the wedge effect caused by the biting, it is possible to significantly improve the adhesion state of the conductive elastic material layer. Moreover, it becomes possible to eliminate the use of expensive conductive agents, and it also becomes possible to realize a significant reduction in the overall cost.

[Brief explanation of drawings]

Figure 1 is a longitudinal sectional view of one embodiment of this invention;
The figure is an enlarged view of the circled part A in Figure 1.
The figure is a longitudinal sectional view of another embodiment of this invention, FIG. 4 is an enlarged portion of the circled portion B in FIG. 3, and FIG. 5 is a longitudinal sectional view of a conventional example. 5... Metal shaft body, 6... Rotating shaft, 7... Conductive elastic material layer, 8... Conductive agent-free adhesive.

Claims (1)

[Scope of utility model registration request] A metal shaft, and a conductive elastic material layer formed directly on the outer peripheral surface of the metal shaft or via a conductive foam layer, and at least a part of the outer peripheral surface of the metal shaft is uneven. The conductive foam material layer or the conductive elastic material layer is formed to have a rough surface and is adhered to the outer circumferential surface of the metal shaft with an adhesive while being in contact with at least the tops of the convex portions of the rough surface. A conductive roller characterized by: