JP3023528B2 - Semi-conductive roller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductive roller, and more particularly to a semiconductive roller similar to a developing roller used as a component of an electrophotographic printer in an output device of a computer application device.

[0002]

2. Description of the Related Art For example, an electrophotographic printer plays an important role as one of output devices of computer-applied equipment because it has a feature of printing characters and figures at high speed and high quality. Since the printing principle is well known, a detailed description of its configuration and operation is omitted, but the developing roller is indispensable for the developing process in the electrophotographic printer.

For example, a conventional developing roller used in an electrophotographic printer has a sheet-shaped conductive silicone rubber bonded and fixed to a shaft surface formed of a cylindrical roller with a conductive adhesive. In the manufacturing method, a conductive adhesive is applied to the outer surface of the above-mentioned shaft, and after performing a sheeting using a kneaded product of a conductor powder and a silicone rubber powder as a sheeting material, rough grinding is performed, and the protrusion is performed. Cut off the sheeting material. Thereafter, after secondary vulcanization, finish grinding is performed, and washing for removing grinding debris, dust and the like is performed, and then subjected to shipping inspection.

[0004] The construction of such a developing roller and especially its adhesive application step are performed by placing a conductive adhesive between a conductive sheeting material of silicone rubber having a relatively high resistance value and a shaft (a good conductor such as a metal). To provide the required resistance to the adhesive layer formed by the adhesive layer and to prevent the sheeting material from moving relative to the shaft so that the developing roller can perform the developing process normally and reliably. It is.

[0005]

The adhesive used for the adhesive layer of the conventional developing roller as described above is a conductive adhesive having an appropriate resistance within a range of specifications. Since the manufacturing method is slightly complicated, workability is poor, and there is a problem that the cost is increased. In addition, if the surface of the shaft is somewhat dirty, there has been a problem that the sheeting material is peeled off from the shaft after molding due to poor adhesion of the soiled surface.

[0006]

According to the present invention, there is provided a semiconductive roller in which a rubber sheeting material bonded to a shaft surface of the roller is bonded and fixed by using an insulating adhesive. The roller may be a developing roller used in an electrophotographic printer, and the thickness of an adhesive layer formed by applying an insulating adhesive is desirably 20 μm at the maximum. Further, it is preferable to use an insulating adhesive prepared by mixing dimethylpolysiloxane, a silane coupling agent and xylene.

[0007]

In the present invention, a semiconductive roller is formed by bonding and fixing a rubber sheeting material adhered to a shaft surface of a roller using an insulating adhesive. Normally, by making the thickness as thin as 20 μm or less, it becomes possible to reduce the resistance of the insulating adhesive layer and to provide a suitable conductivity. The resistance of the insulating adhesive layer made in this way is lower in resistance than the resistance of the outer conductive rubber sheeting material. Since the insulating adhesive layer has a semiconductive film as a whole, the obtained developing roller is suitable for being called a semiconductive roller. In other words, a structure in which a conductive but relatively high-resistance rubber sheeting material is electrically half-floated on a conductor shaft via a resistance film having a lower resistance than the rubber sheeting material (the same function as the above-described conventional configuration) ) Is obtained. In addition, since the used insulating adhesive has a markedly larger adhesiveness than a normal conductive adhesive, the shaft and the rubber sheeting material never peel off after molding and are easily required. The resistance value is obtained. In particular, when using an adhesive prepared by mixing dimethylpolysiloxane, silane coupling agent and xylene, the adhesiveness is large,
In addition, the contribution of the insulating adhesive layer to resistance (reduction in insulation) is enhanced.

[0008]

FIG. 1 is a schematic explanatory view showing an embodiment of a semiconductive roller according to the present invention. In FIG. 1, reference numeral 5 denotes a cylindrical developing roller used as a component of an electrophotographic printer, for example. Reference numeral 10 denotes a shaft D-cut portion (commonly known) provided at one end of the central axis of the shaft 13 of the developing roller 5, and an opposite D-cut portion is provided at the other end. 26 is an insulating adhesive layer formed on the outer surface of the shaft 13 by coating, and 27 is a rubber sheeting layer formed outside the insulating adhesive layer 26. In this embodiment, the insulating adhesive layer 26 is formed by applying an adhesive made by mixing, for example, dimethylpolysiloxane, a silane coupling agent, and xylene to a thickness of about 20 μm. The rubber sheeting layer 27 is an elastic conductive layer made of a kneaded product of silicone rubber and conductive powder, and has a thickness of about 3.2 mm or less.

In the structure of the embodiment shown in FIG. 1, the insulating adhesive layer 26 is in contact with both the outer surface of the shaft 13 and the inner surface of the rubber sheeting layer 27 with strong adhesiveness. The insulating adhesive layer 26 does not peel off later.
Of the rubber seating layer 27 with an appropriate resistance (described later) as a spacer. For this reason, it can have a sufficient function as a semiconductive developing roller.

Next, a method of manufacturing a developing roller according to the present invention will be described. FIG. 2 is a perspective explanatory view schematically showing an adhesive application device for uniformly applying an adhesive to a shaft. First, a liquid insulating adhesive of the above-described mixture is prepared and prepared. Next, the shaft D-cut portion 10 is inserted into the D-cut insertion portion 11 at one end of the shaft 13, and the opposite D-cut portion (not shown) at the other end is fitted into the fixing portion 17 to be rotatably fixed. Next, the power switch 12 is turned on, the shaft 13 is rotated, and the insulating adhesive is applied to the brush 1 for applying the adhesive.
4. Apply evenly. The shaft 13 coated with the insulating adhesive is mounted on a dedicated drying jig 15 shown in FIG.
Baking is performed in a drying furnace 16 at 150 ° C. for 15 minutes to form an insulating adhesive layer 26 (see FIG. 1) of about 20 μm. A silicone rubber sheeting material is molded together with the shaft on which the adhesive has been applied to form a rubber sheeting layer 27 (FIG. 1). Then, secondary vulcanization, finish grinding, and finish cleaning are sequentially performed, and the process is completed. In this case, the rubber sheeting layer 27 is
No peeling was observed.

Here, as an explanation of the operation of the semiconductive roller,
The function of the developing roller will be described with reference to the schematic diagram of the printing process unit of the electrophotographic printer in FIG. FIG.
, The photosensitive member of the photosensitive drum 1 rotated in the direction of the arrow by the charging roller 2 (formed on the surface of the drum)
Is uniformly charged, and then receives light from the LED head 3 to form an electrostatic latent image on the photosensitive drum 1 by scanning focused light based on print information (actually, blinking of the focused light). That is, the resistance of the portion of the photoconductor irradiated with light is reduced, and the area where the resistance is reduced becomes an electrostatic latent image. Note that the photoreceptor originally has a high resistance value close to the insulating property in a dark place, so that a portion not irradiated with light remains in a high resistance state. The electrostatic latent image formed on the photosensitive drum 1 is
The toner is moved to the developing roller 5 and rubbed against the toner layer formed by the developing roller, and the toner 6 adheres to the toner layer. The developed image of the toner 6 moves to a region in contact with the medium (for example, paper) 18 and is transferred by the transfer roller 7. Then, the image is fixed by the fixing roller 9 and printing is completed. Reference numeral 8 denotes a cleaning roller for returning the surface of the photoreceptor after development to a state before charging and for cleaning.

The above is a brief description of the printing process.
Here, in order for the developing roller 5 to completely execute the above-described process, the resistance between the rubber sheeting layer 27 and the shaft 13 is 0.5 × 10 ^{6 in} partial resistance.
It must be within the range of １1 × 10 ⁹ Ω. In the case of the present embodiment, the insulating adhesive layer 26 is formed using an insulating adhesive, but if the thickness is set to a maximum of 20 μm (20 μm or less), the silicon rubber material itself of the rubber sheeting layer 27 becomes It became clear that as long as it was in a good quality area, it would not be out of the above range. That is, in this state, it has been found that the insulating adhesive layer 26 does not become a complete insulating layer but has an appropriate resistance, that is, conductivity. As data supporting this, there is an experimental result shown in the diagram of FIG. The horizontal axis in FIG. 5 is the thickness of the insulating adhesive layer 26, and the vertical axis is the partial resistance value of the insulating adhesive layer. From this figure, a resistance value less than the above resistance condition range is obtained at a film thickness of 20 μm or less. That is,
As shown in the figure, the rubber sheeting layer 27 has a resistance layer of about 0.6 × 10 ⁵ Ω (the insulating adhesive layer 2).
6), and has a semiconductive layer on the outer surface of the roller (shaft) as a whole (that is, a semiconductive roller). However, in this case, considering the adhesiveness, the film thickness must be at least 5 μm or more.

In the above-described embodiment, a case has been described in which the developing roller is used as a component of the electrophotographic printer as the roller. However, the present invention is not limited to the developing roller, but has the same function and configuration. Needless to say, the present invention can be applied to various types of rollers.

[0014]

As described above, according to the present invention, a semiconductive roller is formed by bonding and fixing a rubber sheeting material bonded to the shaft surface of the roller using an insulating adhesive. Since the thickness of the adhesive is usually 20 μm or less, the resistance value of the insulating adhesive layer can be reduced to be within a predetermined standard. And
Since the insulating adhesive is used, the adhesive strength becomes necessary and sufficient compared to the conventional conductive adhesive.
The rubber sheeting agent was not peeled off from the developing roller surface, and the effect as an adhesive was significantly improved.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of a developing roller showing one embodiment of a semiconductive roller according to the present invention.

FIG. 2 is an explanatory perspective view schematically showing an adhesive application device applied to a developing roller of the present invention.

FIG. 3 is a perspective view showing a general developing roller drying jig.

FIG. 4 is a schematic explanatory view showing a printing process unit of a general electrophotographic printer.

FIG. 5 is a diagram showing the relationship between the thickness of the insulating adhesive layer according to the present invention and the partial resistance value of the insulating adhesive layer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Charging roller 3 LED head 4 Developing blade 5 Developing roller 6 Toner 7 Transfer roller 8 Cleaning roller 9 Fixing roller 10 Shaft D-cut part 11 D-cut insertion part 12 Power switch 13 Shaft 14 Adhesive application brush 15 Drying cure Tools 16 Drying furnace 17 Fixing part 18 Medium 26 Insulating adhesive layer 27 Rubber sheeting layer

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Takao Sakai 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (56) References JP-A-6-110303 (JP, A) JP Hei 5-330712 (JP, A) "Adhesion Handbook (2nd edition)" published by Nikkan Kogyo Shimbun on August 30, 1989, edited by the Japan Adhesion Association, pages 524-525, pages 361, 762-763. (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 15/08-15/095 B65H 27/00 F16C 13/00

Claims (2)

(57) [Claims] 1. A rubber band bonded to a shaft surface of a roller.
Coating material is bonded and fixed using an insulating adhesive,
Layer of an adhesive layer formed by applying the insulating adhesive
Characterized by a maximum thickness of 20 μm,
La. 2. The insulating adhesive according to claim 1, wherein the insulating adhesive is dimethylpolysiloxane.
Mixed with sun, silane coupling agent and xylene
2. The semiconductor device according to claim 1, wherein
Electric roller.