JPS5814858A - Contact charger - Google Patents

Abstract

PURPOSE:To charge stably and uniformly, irrespective of environmental humidity, by forming a contact of a contact charger for charging a photosensitive body of an electrophotographing device, by forming a silane coupling agent treated film and a silicone resin film in order on the surface of a conductive fiber. CONSTITUTION:A contact charger 2 for charging the surface of a photo-sensitive body 1 is constituted by superposing in layers in order an insulating cushion material 4, an electrode 5, an electric conductor 6 and a contact 7 on the surface of a substrate 3. This contact 7 is constituted by forming a silane coupling agent treated film 14 on the surface of a synthetic fiber, etc. 12 containing a carbon fiber or conductive carbon fine particles, and forming a silicone resin film 13 on the surface of the film 14. As a result, by the film 14, the film 13 is strongly joined with the fiber 12, is not peeled off, and by the film 13, humidity dependence of the contact 7 becomes small, and it is possible to give uniform charging which can be used for a long period of time and safely, to the photosensitive body 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to, for example, a contact charger that charges the surface of a photoreceptor of an electrophotographic machine by applying a voltage while contacting the light surface of the photoreceptor with a contactor.

Conventionally, a corona charger uses corona discharge as a charger for a photoreceptor in an electrophotographic camera, a roller charger charges a conductive roller by applying a bias voltage, and a dielectric roller is charged after being charged with an electrostatic charge. Examples include a dielectric transfer roller charger for transferring onto a photoreceptor. In roller chargers and dielectric transfer roller chargers, uneven charging of the photoreceptor occurs due to variations in the conductivity or dielectricity of the roller material and variations in the contact pressure between the roller and the photoreceptor, and uniform charging is not achieved. In addition, corona chargers that use corona discharge are not suitable for scales that require a high-voltage power source that generates high voltage to generate corona discharge, and they shorten the life of the photoreceptor due to the generation of oscillations due to corona discharge. There is a risk of wire breakage.

Therefore, in recent years, contact chargers have been proposed that solve the above problems all at once. In this method, a υ contact is constructed of thin conductive fibers, and by applying a bias voltage to this contact and bringing it into contact with the optical surface of a C photoreceptor, different surfaces of the photoreceptor are charged. However, the above-mentioned contacts have disadvantages in that their resistance varies greatly depending on humidity, their resistance varies, and they cannot perform stable and uniform charging.

The present invention has been made based on the above-mentioned circumstances, and its object is to reduce the humidity dependence of the resistance of a contact and to provide two types of resistance of the contact.

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a photoreceptor as a charged member of an electrophotographic machine, and this problem can be solved by contacting the surface of the photoreceptor 1 with
A contact charger 2 for charging the front side is provided. This contact charger 2 includes an insulating cushioning material 4, an electrode 5, a conductive electron, and an insulating cushion material 4, an electrode 5, and a conductive electron at the front part of a base 3 disposed along the width direction of the photoreceptor 10, that is, the part facing the surface of the photoreceptor 1. 6 and the contact 7 are superposed in layers and are in contact with each other so as to cover the front surface and both side surfaces of the base body 3. The conductive element 6 is divided into two parts, a DC conductive plate 6a and an AC conductive plate 6b, spaced apart in the width direction, and the DC conductive plate 6B has a negative terminal of a DC power source 8 whose positive terminal is grounded, The other end of a first capacitor 9 whose one end is grounded and which bypasses alternating current is connected to the AC conductive plate 6.
b is connected to the other end of an AC power source 11 whose one end is grounded via a second capacitor 10 that blocks direct current. Note that the photoreceptor 1 is grounded.

As shown in FIGS. 2 and 3, the contactor 7 has a silane coupling agent treated film 14 and a silicone resin film 13 applied in this order to the surface of a brush-shaped conductive fiber 12. It is formed. The fibers 12 can be anything that is generally called a fiber. For example, inorganic fibers such as carbine fiber and stainless steel fiber, rayon, acetate, vinylon, nylon, and vinylidene.

Examples include isoelectrically modified chemical fibers such as polyester, acrylic, and N+2 urethane. Further, as the above-mentioned cyjinkazo agent, for example, the general formula ynst
x, (However, Y FiCH2=CH-.

and H2N・(CH2)2Nl((CH2)5+,
X is 10CH3.

-0C2H5, -0CH2CH20CH5, n = 1
An integer of ~2, m=an integer of 2 to 3, 'C-nJ1n=4
, product name KA manufactured by Shin-Etsu Silicone Co., Ltd.
1003.

KBE 1003, KBC1003, KBM 30
3.

KBM 403, KBM 503, KBM 6
02, KBM603, manufactured by Nippon Unicar Co., Ltd. Product name A-
1100, A1120, etc. In addition, the silicone mentioned above is methylhydrodiene silicone, S)
Methyl silicone, etc., which are generally used for textiles, are manufactured by Toshiba Silicone Co., Ltd. under the trade names TSW831 and TSM630, and manufactured by Shin-Etsu Silicone under the trade names PolonMR and PolonMK.
114° MP-38, etc.

In the contactor 7 configured in this manner, the protective resistance of the silicone resin film 13 is formed on the surface of the fiber 12, so that the dependence of resistance on humidity is small and variation in resistance can be prevented. Moreover, this contactor 7 was formed by applying a silicone resin film directly to the surface of the fiber without applying a silane coupling agent 5-treated film, and the adhesion between the fiber and the silicone resin film was poor, and the initial characteristics were poor. However, after long-term use, the silicone resin film peels off from the fibers and loses its properties.
If the silicone resin film 13 has good adhesion to the fibers 12, the silicone resin film 13 will not peel off from the fibers 12 even after long-term use, and the initial properties can be maintained. Since it can be applied evenly and floatingly on the surface, the desired resistance value can be obtained. Therefore, the contact charger 2 using the contact 7 can stably and uniformly charge the surface of the photoreceptor 1 over a long period of time.

Next, the first experimental example is to explain the experimental example. First, the first experimental example is a carbon array organic conductive material in which fine particles of conductive carbon black are uniformly dispersed and arranged in streaks on an acrylic polymer base. A fiber (product name 5k-7 manufactured by Toshisha Co., Ltd.) 12 was formed into a brush-like structure, and this was subjected to ultrasonic waves in an aqueous solution of a silane coupling agent (product name KBM-603 manufactured by Shin-Etsu Silicone Co., Ltd.). Soak for a sufficient amount of time, then take out and air dry.

Thereafter, it is dried in a dryer at about 100° C. for 8 hours to form a silane cassilling agent-treated film 14. Next, apply silicone (trade name: TSW831 manufactured by Toshiba Silicone Co., Ltd.).
) 3% treatment liquid and catalyst (product name CW manufactured by Toshiba Silicone Co., Ltd.)
The sample was immersed in a solution containing the same amount of 80) and pre-dried at 100°C for 1 hour, and then dried at 150°C.
A heat treatment is performed for 5 minutes to form a silicone resin film 13. The contact charger 2 using the contact 7i formed in this manner had a change in resistance value with respect to humidity of about one digit, had little humidity dependence, and was able to provide a stable charging potential to the photoreceptor 1. In addition, this contact charger 2 is a contact charger using a contactor in which a silicone resin film is directly applied to the surface of the fiber without applying a silane cassilling agent treatment film.
It could withstand a period equivalent to 20,000 copies or more, whereas it could only withstand a period corresponding to 1,000 to 15,000 copies.

The second commercial example is a triple-structured composite fiber (manufactured by Kanetsu Gosen Co., Ltd.) in which a nylon conductive layer containing a large amount of conductive carbon black particles and ordinary nylon are joined in a ZangPwi, Chi shape. (Product name: Beltron) 12 in a brush shape.
On the other hand, this is immersed in a 1% aqueous solution of a silane cassilling agent (trade name A-1100, manufactured by Nippon Unicar Co., Ltd.) while applying ultrasonic waves, the surface of the fiber is thoroughly wetted, taken out, and air-dried. Next, hot air at about 120° C. is applied to form a silane cassilling agent treated film 14. Next, this is thoroughly treated by immersing it in a 6-chi treatment solution of silicone (trade name Polon MR, manufactured by Shin-Etsu Silicone Co., Ltd.) while applying ultrasonic waves. Remove and air dry. Next, a heating process is performed by applying hot air at about 160° C. to form a silicone resin film J3. The contact 7 thus formed was glued to the At1l pole 5, and DC-800V was applied to the device 2 due to the contact zone.
When the surface of nOPjA element 1 was charged, approximately 50
A uniform charging potential of 0 V was obtained and remained stable without change even in an atmosphere with a humidity of 20% to 80°C. Also, 1
It can withstand use for a period equivalent to 5,000 to 30,000 copies, and when the contact 7 was observed with a scanning electron microscope (SEM), it was found to be a silicone resin film resin m1s.

There was almost no peeling.

In the third experimental example, rayon fibers containing fine carbon particles (trade name: Keo Ledge, manufactured by Unitika Co., Ltd.) 12 were grafted onto conductive rubber to form a brush shape, and a coupling agent ( The process was carried out in the same manner as in the first example using Toshiba Silicone Co., Ltd. (trade name: KBM-602) and Toshiba Silicone Co., Ltd. (trade name: TSM-6a o ).

The contact charger 2 using the contact 7 formed in this manner was able to withstand use for a period of time equivalent to more than 20,000 copies.As explained above, according to the contact charger of the present invention, Since the contact was formed by applying a silane cassilling agent treatment film and a silicone resin film on the surface of the fiber in this order, the humidity dependence of the contact was small.
It also prevents variations in the resistance of the contact, and the silane cassilling agent treated film provides good adhesion between the fibers and the silicone resin film, ensuring that the silicone resin film will not peel off from the fibers even after long-term use. Initial characteristics can be maintained.

Moreover, since the silicone resin film can be uniformly and thickly applied to the surface of the fiber, a desired resistance value can be obtained. Therefore, excellent effects such as being able to stably and uniformly charge the surface of the plate band over a long period of time are achieved.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a schematic configuration diagram of a contact charger, FIG. g2 is a vertical side view of the contact, and FIG. 3 is an enlarged vertical side view of the contact. 1... Charged body (photoreceptor), 2... Contact charger, 7
... contactor, 12 ... fiber, 13 ... silicone resin film, 14 ... silane cassilling agent treated film. -1〇-

Claims (1)

[Claims] The object to be charged is charged by applying a voltage while the contact is in contact with the object to be charged. A contact charger characterized in that it is formed by applying the following steps: