JPS6224280A - Developing device - Google Patents

Abstract

PURPOSE:To apply substantial electric charge of a desired polarity to a developer by forming a control member of a leaf spring member and soft elastic material and incorporating a quaternary ammonium salt into the soft elastic material, CONSTITUTION:The control member 3 is constituted by adhering the soft elastic material 3b to the leaf spring 3a. A leaf spring made of phosphor bronze, silicon steel, stainless steel or the like to 0.03-0.5mm thickness is usable for the leaf spring 3a. A soft elastic material for which silicone rubber, ethylene propylene rubber, styrene butadiene rubber, epichlorohydrin rubber, chloroprene rubber, butyl rubber or the like having 10-70 deg. hardness is used as a base material and into which 0.05-20wt% quaternary ammonium salt is incorporated usable for the soft elastic material 3b. The content of the quaternary ammonium salt is further preferably 0.1-5wt%. The example of the quaternary ammonium salt includes coatamin 24P, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention generally relates to a developing device, and more particularly, to a developing device in which a monocomponent developer supplied onto a developer carrier is formed into a developer layer of a predetermined thickness by a regulating member. The present invention relates to a one-component developing device that conveys a developer layer to an electrostatic latent image and develops it into a visible image.

BACKGROUND TECHNOLOGY Dry developing devices that develop electrostatic latent images formed on electrostatic latent image holders have conventionally used a two-component developer consisting of toner and gear, and the toner is charged by friction with the carrier. Two-component developing devices have been actively developed and put into practical use, in which a charged toner is electrostatically attracted to an electrostatic latent image by applying an electric charge to the electrostatic latent image. Typical two-component developing methods include the h-skate developing method and the magnetic brush developing method.

From the viewpoint of copy quality such as solid black reproducibility, magnetic brush development methods have recently become mainstream. Although the developing method using a two-component developer consisting of toner and carrier is sufficiently practical, it has recently been developed from the viewpoints of compacting the installation space of the developing device and preventing deterioration of the developer. , a one-component developing method and device using a one-component developer consisting only of toner has been proposed.
Among these, non-magnetic developers have been adopted from the viewpoint of high transparency and have been applied to color development with good results.

This non-magnetic component development method has previously been proposed in US Patent No. 2.
The touchdown development method disclosed in U.S. Pat. Although this method is simple, it has many drawbacks, such as the large size of the device and the need to periodically clean the corotron wire.

JP-A-47-13088 and JP-A-47-13089
No. 1, No. 1, No. 1, No. 1, No. 1, No. 1, No. 1, No. 2003, No. 1, No. 1, No. 1, No. 1, No. 1, No. 1, No. 1, No. 1, No. 2, No. 2, 1996, and No. 2, No. 1, No. 1, No. 1, No. 1, No. 1, No. 2, No. 1, No. 1, 2006, and No. 2, No. 1, No. 1, No. 1, No. 1, No. 1, No. 1, and No. 1, No. 1, No. 1, No. 1, No. 1, No. 1, No. 1, No. 1, No. 1, No. 1, 2003 and 2003, describes inventions relating to impression development and toner dispensing processes suitable for impression development. This impression development consists of a pressure developing drum that carries toner and conveys it to the photoconductive material, a toner distribution blade, etc. As the pressure development drum rotates, the toner flowing under the toner distribution blade is charged by friction due to contact with the blade. This technique involves forming a uniform layer on a photoconductive material and selectively transferring it to an electrostatic latent image by contacting the photoconductive material. The toner distribution blade is a doctor blade made of polytetrafluoroethylene or the like having a circular tip, and one to three doctor blades are used. On the other hand, the pressure development surface is formed of, for example, resin-graphite, and a flexible conductor and an elastic plating material are provided as an underlying layer.

However, even with this configuration, in order to obtain a higher quality copy image, it is necessary to form a more uniform and thin deposit of toner on the pressure development surface and to impart an appropriate charge to the toner.

Problems to be Solved by the Invention However, according to the conventional one-component developing device, an electric charge having a desired polarity is imparted to the developer by bringing the regulating member into contact with the developer carrier. Since the friction time is relatively short, a sufficient amount of charge of the developer cannot be obtained, which often results in a copy image with so-called "fogging" in which a large amount of developer adheres to the non-image areas of the electrostatic latent image holder. there were.

In addition, since it is not possible to apply a charge to the developer every 4 minutes, the developer is not electrostatically supported sufficiently on the developer carrier due to the stress of the regulating member, and the am of the developer becomes uneven. There is a problem in that the developer spills from the top of the developer carrier and contaminates the area around the developing device.

An object of the present invention is to solve the above-mentioned problems, and to form a uniform thin layer of developer with a predetermined thickness by imparting a sufficient charge to the developer formed as a thin layer on a developer carrier. The object of the present invention is to obtain a homogeneous visible image with less fog on an electrostatic latent image holder.

In order to solve the problems of the prior art described above, the present invention provides a developer carrier and a developer carrier that contacts the developer carrier to spread a thin layer of developer. As well as forming on top j! ! In a developing device that visualizes an electrostatic latent image on an electrostatic latent image holder by providing a regulating member that applies an electric charge to the developer by triboelectric charging, the regulating member is arranged at least in a contact portion with the developer carrier. A developing device is provided, characterized in that it is formed of a soft elastic body, and the soft elastic body contains a quaternary ammonium salt in a base material.

According to a preferred embodiment of the present invention, the regulating member
□ indicates the elastic body attached to the developing device body and the elastic body
: It consists of a soft elastic body □ which comes into contact with the surface of the developer carrier at the tip thereof, and the base material of the soft elastic body contains 0.05 to 20% by weight of a quaternary ammonium salt. More preferably, 0.1 to 5% of quaternary ammonium salt is contained.

Examples of the quaternary ammonium salt include Cortamine 24P, Cortamine 86P Conc, Cortamine 60W, Cortamine 86W, Cortamine D86P (Kao Soap), and P-51 (Orient Chemical).

The action regulating member is made soft at the contact area with the developer carrier.
'By being composed of an elastic body, for example, coarse toner particles can be prevented from entering the contact area between the soft elastic body and the developer carrier.
: If the toner particles enter the soft elastic body, only the portion of the coarse toner particles deforms. This prevents the stress applied to the toner particles from becoming larger than necessary.
Furthermore, in the contact area, it is possible to eliminate the possibility that the gap between the regulating member and the developer carrier becomes unnecessarily large and other fine toner particles enter therein more than necessary.

In addition, if a foreign object gets between the regulating member and the developer carrier, the soft elastic body constantly vibrates mechanically with the developer carrier, making it easy to remove the foreign object. Furthermore, after the foreign matter is removed, the dented portion of the soft elastic body due to the foreign matter quickly returns to its original state. This makes it possible to form a uniform developer layer on the developer carrier in a stable manner over time.

Furthermore, quaternary ammonium salt is added to the soft elastic body from 0°05 to
Since the content is 20% by weight, the triboelectric charging characteristics of the toner due to the regulating member can be significantly improved. As a result, when an electrostatic latent image is developed by the developing device of the present invention, a clean copy image with less fog can be obtained.

Hereinafter, the present invention will be described in more detail based on embodiments with reference to the drawings.

8 1- Referring to FIG. 1, a schematic configuration diagram of a developing device of the present invention is shown. In FIG. 1, below a hopper 2 in which developer 1 is stored, a developer carrier 5 carrying developer 1 and a developer supply member 4 are provided in pressure contact with each other and are rotatable. , the regulating member 3 is pressed against the developer carrier 5 with uniform pressure over the axial direction of the developer carrier 5. An electrostatic latent image holder 7 holding an electrostatic latent image 8 facing the developer carrier 5 is rotatably provided, and the developer carrier 5
A bias voltage is applied by a bias power supply 9 to the two. 6 is a sealing material.

The image side 1 is, for example, a non-magnetic, -component type developer, in which a polarity control agent such as a pigment such as carbon or a metal-containing azo dye is dispersed in various thermoplastic resins such as styrene resin or acrylic resin, and then pulverized. The particles are classified to have a size of 5 to 20 μm, and in some cases, hydrophobic silica may be added in an amount of 0.5 to 2.0% by weight based on the developer particles to improve fluidity. The developer actually used in this example was 2% by weight of azo dye in a styrene-acrylic binder.
and a negatively chargeable toner containing 10% by weight of carbon black.

Regulation member 3 is 5LJS304C8P3/4H0°1mm
A soft elastic body 3b containing 0.5% by weight of Cortamine 24P was bonded to a base material of a silicone rubber (hardness: 50 degrees) to a leaf spring 3a having a thickness of +. The silicone rubber base material is KE65, which is a heat-curable silicone rubber.
0-Ll, KE850-LJ, KE554-LJSKE
555-LISKE752-U (Shin-Etsu Silicone)
, TSE221, TSE270, TSE260 (Toshiba Silicone), etc. can be used, and quaternary ammonium salt is kneaded into these heat-curable silicone rubbers using three rolls, and the mixture is heated and vulcanized by putting it in a mold. It is then cut to have a thickness of 1#l, a width of 10#III, and a length of 300Ill+, and is bonded to the surface of the leaf spring 3a of 5US30jC5P3/4H0,1jm with an adhesive. The silicone rubber base material actually used in the experiment of this example was KE650.
-U, and 0.5% by weight of Cortamine 24P was added thereto to form a soft elastic body 3b.

° In general, the plate spring 3a of the present invention can be made of phosphor bronze, silicon steel, stainless steel, etc. with a thickness of 0.03 to 0.5 m, and the soft elastic body 3b can be made of silicone rubber, ethylene, etc. The base material is propylene rubber, styrene-butadiene rubber, ebichlorobidrin rubber, chlorobrene rubber, butyl rubber, etc. with a hardness of 10 to 70 degrees, and contains 0.05 to 20% by weight of quaternary ammonium salt. It is possible to adopt More preferably, the content of the quaternary ammonium salt is 0.1 to 5% by weight.
Examples of quaternary ammonium salts include Cortazine 24
P1 Cortamine 86P Conch, Cortamine 60W1 Cortamine 86W1 Cortamine 086P (The above are Hanatamaishi @)
, or P-51 (Orient Chemical).

The developer supply member 4 has a cylindrical shape in which an elastic body 4b such as urethane rubber is bonded to a metal core 4a, and is pressed against the surface of the developer carrier 5 at a predetermined pressure. The developer carrier 5 is composed of a roll made of conductive phenol resin, for example, and the regulating member 3 is attached to the roll with a diameter of 50 to 500'.
They are pressed together with a linear pressure of j/cm.

The line pressure actually adopted in this example was 100 g/υ,
The developer carrier 5 was rotated at a circumferential speed of 127 III #l/sec, and the amount of charge of the developer layer on the developer carrier was measured, and the results are shown by broken lines in FIG. As a comparative example, a solid line in FIG. 3 shows a silicone rubber containing no quaternary ammonium salt. As is clear from the graph in Figure 3, by containing the quaternary ammonium salt in the silicone rubber, the average charge amount of the toner is -2μC10
r to -15 μc/g r, and there was no presence of reverse polarity (positively charged) toner.

Next, the operation of the developing device of the present invention shown in FIG. 1 will be explained below. The developer 1 in the hopper 2 is supplied onto the elastic body 4b of the developer supply member 4 by gravity, and is slightly tribo-electrified by the friction between the supply member 4 and the developer carrier 5, and is then given an electric charge. The developer is sent to the developer carrier 5, and then the regulating member 3 causes the developer to have a predetermined thickness.
m developer layers are formed on the developer carrier 5, and
Friction is also generated between the regulating member 3, the developer 1, and the developer carrier 5, so that the developer is charged. At this time, the soft elastic body 3b of the regulating member 3 is made of silicone rubber as a base material,
Since this contains 0.5% by weight of Cortamine 24P, the triboelectric charging characteristics with the developer 1 can be significantly improved, so that the developer layer on the developer carrier 5 is sufficiently It becomes charged and is formed into a thin layer of uniform thickness.

This developer iJ layer is sent to the development area facing the electrostatic latent image carrier 7 by rotating the developer carrier 5 while applying a bias voltage to the developer carrier 5, and the electrostatic latent image 8
The developer flies toward the electrostatic latent image 8 due to the electric field between the developer and the developer carrier 5, is deposited on the electrostatic latent image 8, and is developed into a visible image.

In this way, the regulating member 3 is connected to the spring plate material 3a and the soft elastic body 3b.
Since the soft elastic body contains a quaternary ammonium salt, the triboelectric charging characteristics of the soft elastic body 3b with respect to the developer 1 can be significantly improved. given a charge. According to the present invention described in detail above, a stable and uniform thin layer of developer having sufficient charge can be formed on the developer carrier 5, so that the electrostatic potential on the electrostatic latent image carrier 7 The image 8 can be developed faithfully without causing fog.

The developer that did not contribute to development remains in a non-uniform state on the developer carrier 5 that has passed through the development area, and a portion of this remaining developer is collected by the supply member 4, and the developer is present. After the developer 1 is supplied by the supply member 4 to the areas where the developer 1 is not formed, and the state is corrected to be almost uniform, the developer 1 is sufficiently charged again by the regulating member 3, and a developer layer of a constant thickness of 311I is formed. It is formed on the carrier 5.

Example 2 Kotajin 86P was added to the silicone base material used in Example 1.
A regulating member 3 was formed by kneading 0.2% by weight of concrete and using the same conditions as in Example 1 except for the other conditions. This regulating member was adopted in the developing device shown in FIG. 1, and the amount of charge on the developer layer on the developer carrier 5 was measured under the same conditions as in Example 1. As a result, the average charge was -18 μC/lr. Obtained. Further, as a result of a copy test using this developing device, a clear copy image with no fog in the non-image area was obtained.

Example 3 Using ethylene propylene rubber as the base material, the actual
.

Similarly to Example 1, Cortamine 24P was mixed in at a weight of 0.5% to form a soft elastic body 3b, and this was adhered to the same spring plate material 3a as in Example 1 to form the regulating member 3. When this regulating member was used in the developing device shown in FIG. 1 and the average band 1ffi of the developer on the developer carrier 5 was measured, an average charge amount of -25 μc/gr was obtained. A copy test was conducted using this developing device, and as a result, a clear copy image with no fog in the non-image area was obtained. As a comparative example, when ethylene propylene rubber without quaternary ammonium salt kneaded is used as the soft elastic body 3b, the average charge amount of the developer is -3.5 μC/gr, and the copied image also has a lot of fog. Met.

Example 4 A soft elastic body 3b was formed using the same silicone rubber and Cortamine 24P as in Example 1, and the content of Cortamine 24P was varied within the range of 0.01 to 30% by weight to form a strip.
The measurement results are shown in Figure 4. As is clear from Figure 4, when the content of Coatamine 24P is less than 0.05% by weight, the effect of adding Coatamine 24P is not so great, and when it is more than 20% by weight, the surface of the rubber is not uniform and the developer It is observed that the amount of charge is also reduced. As a result, the content of Cortamine 24P is preferably 0.05 to 20% by weight, more preferably 0.1 to 5% by weight.

Example 5 As shown in FIG. 5, a two-component magnetic developer 1' consisting of toner and carrier is used as the developer, and a conventionally known two-component developing magnet 10 is used as the developer supply member. Then, the weakly charged developer 1' is sent onto the developer carrier 5. Even in this case, if the regulating member 3 of the present invention was used, the developer could be sufficiently charged, and no fog was observed in the copied image.

Effects of the Invention As described in detail above, in the present invention, the regulating member is formed of a spring plate material and a soft elastic body, and the soft elastic body contains a quaternary ammonium salt. Since the triboelectric charging characteristics can be significantly improved, it is possible to provide the developer with a sufficient charge of a desired polarity. Further, when an electrostatic latent image is developed by the developing device of the present invention, a clean copy image without any fogging can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of the developing device of the present invention, FIG. 2 is an enlarged sectional view of a regulating member used in the developing device of the present invention, and FIG. 3 is a diagram showing the charge amount distribution of the developer on the developer carrier. 2 is a graph showing the present invention in which the broken line represents the present invention and the solid line represents a comparative example that does not contain a quaternary ammonium salt. Fig. 4 is a graph showing the relationship between the content of Cortamine 24P and the average charge amount of the developer, and Fig. 5 is a graph showing the relationship between the content of Cortamine 24P and the average charge amount of the developer. It is a schematic block diagram which shows the other embodiment of this invention used. 1...Developer, 2...Hopper, 3...
Regulating member, 3a... Spring plate material, 3b... Soft elastic body, 4... Developer supply member, 5... Developer carrier, 7... Electrostatic latent image holder, 9...・Bias power supply, 10...magnet roll.

Claims (1)

[Claims] A developer carrying member and a regulating member that comes into contact with the developer carrying member to form a thin layer of developer on the developer carrying member and apply an electric charge to the developer by frictional charging are provided, and the electrostatic latent In a developing device that visualizes an electrostatic latent image on an image carrier, the regulating member is formed of a soft elastic material at least at a contact portion with the developer carrier, and the soft elastic material has a fourth layer in the base material. A developing device characterized by containing a class ammonium salt.