JPH11143221A - Developer amount regulating member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developer amount regulating member capable of obtaining a stable image having neither stripe nor irregularity without being influenced by the edge accuracy of a supporting member. SOLUTION: This member consists of a resin material satisfying following physical material. (A) its flexural modulus by ASTM D790 is 15000-100000 kg/cm<2> in the temperature environment of 230 deg.C, and (B) its creep characteristic after imposing the load of 210 kg/cm<2> for 1000 hours is <=1.5% in the temperature environment of 23 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device for developing and visualizing an electrostatic latent image formed on an image carrier, the developing device carrying and transporting a developer to a developing section. A developer amount regulating member that presses against the development carrier with a developer interposed therebetween to regulate the amount of the developer applied on the surface of the developer carrier and imparts electric charge to the developer by triboelectric charging. Things.

[0002]

2. Description of the Related Art At present, as a method of restricting a layer thickness of a developer 6 (hereinafter also referred to as a toner) carried and transported by a developing carrier 3 (hereinafter also referred to as a developing sleeve) to a developing section, a rubber is applied to the developing sleeve. Or a metal developer amount regulating blade 4
(Hereinafter, also referred to as a developing blade), and a toner is passed between the abutting portion of the developing blade and the developing sleeve to regulate the toner, thereby forming a thin toner layer on the developing sleeve and abutting. A method of imparting triboelectric charge (tribo) for developing a toner latent image by friction at a portion is employed. As a rubber developing blade, a sheet of urethane rubber or the like is used alone or a metal supporting member is used. Is used with

[0003]

However, with the emergence of various new types of toners, it is important to improve the performance of the developing blade in terms of triboelectricity and anti-fusing properties. Specifically, from the viewpoint of energy saving, low melting point toner (sharp melt toner) for fixing at a lower temperature than before, and non-mag toner and polymerized toner which do not have magnetism due to colorization have appeared. The low-melting toner has a problem in that the toner adheres to the developing blade and causes an image defect, and the toner is reduced by reducing the contact pressure between the developing sleeves of the developing blade.

However, when the contact is performed at a low pressure, a higher frictional charging ability is required for the surface material of the developing blade.
Conventionally used materials such as urethane rubber have a problem of insufficient triboelectric charging ability. Even for non-mag toner, the toner itself does not have magnetism, so it is necessary to apply a high triboelectric charge to the toner and coat it on the developing sleeve.However, if urethane rubber is used for the surface material of the developing blade, As described above, there is a problem that toner is scattered in the developing container due to insufficient triboelectric charging ability, thereby contaminating the inside of the container. Therefore, at present, nylon or the like is used as a material having a high triboelectric charging ability as a surface layer material, and the effect is shown.

In the case where nylon is used as the surface material of the developing blade, since nylon itself is a resin having no elasticity, it is necessary to coat the rubber and then adhere it to a spring metal plate. Have been. The spring metal plate ensures uniform contact with the developing sleeve, but in the bonding process, the edge accuracy of the metal plate and the application accuracy of the adhesive can be important functions of the developing blade. In other words, unevenness of the edge of the metal plate, unevenness of the surface of the developing blade due to the adhesive wrapping around the back surface of the metal plate, and the like may cause problems such as streaks on an image. For this reason, at present, a great deal of cost is required for controlling the edge precision of the metal plate and controlling the primer coating process.

An object of the present invention is to provide an inexpensive developer amount regulating member free from the above-described problems such as image streaks.

[0007]

The above object is achieved by the following means.

That is, the present invention provides a container for accommodating a developer, a developing carrier for carrying and transporting the developer from the container to a developing section, and pressing the developing carrier with the developing carrier by pressing the developer via the developer. A developer amount regulating member that regulates the amount of the developer applied on the body surface and imparts electric charge to the developer by frictional charging, wherein the supporting member of the developer amount regulating member is (A) ) In a temperature environment of 23 ° C, A
Flexural modulus according to STM D790 is 15000-10
A resin material of 0000 kg / cm ² , (B)
In a temperature environment of 23 ° C., the resin material has a creep characteristic after applying a load of 210 kg / cm ² for 1000 hours of 1.5% or less, and the mechanical properties of (A) and (B) above A developer amount regulating member comprising a resin material to be filled is proposed, wherein the developer amount regulating member is polysulfone, and a support member of the developer amount regulating member is 0.1 mm to 5 mm. Including polysulfone having a thickness of

According to the present invention, the uniform contact with the developing sleeve becomes possible due to the bending elastic modulus of the polysulfone.
In addition, because of its excellent creep resistance, there is no problem such as a decrease in the contact pressure to the developing sleeve even during long-term use, and the edge of the polysulfone sheet is cut by post-processing the polysulfone sheet edge. Irregularities on the surface of the developing blade due to non-uniformity of edge precision that may occur in the portion and the adhesive wrapping around the back surface of the support member can be removed, and problems such as streaks on an image can be prevented.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail.

FIG. 1 is a side view of a development regulating member of the present invention, and FIG. 2 is a cross-sectional view showing a configuration of a developing device to which the present invention is applied. As shown in FIG. 1, the present invention comprises a support member 4a and a frictional charging member 4b attached to the tip of the support member 4a.
As shown in FIG. 2, the amount of the developer applied to the surface of the development carrier 3 by pressing against the developer carrier 3 via the developer conveyed from the container 2 containing the developer composed of the toner 6 And imparts a charge to the developer by frictional charging. Support member 4 of developer amount regulating member 4 of the present invention
a is (A) ASTM D7 in a temperature environment of 23 ° C.
The flexural modulus according to 90 is 15,000-100,000 kg
It is a resin material is / cm ^2, at (B) 23 ° C. temperature environment, it creep properties after adding 1000 hours the load of 210 kg / cm ² is a resin material is not more than 1.5% And a resin material satisfying the mechanical properties of the above (A) and (B).

Here, the flexural modulus is 15000 kg.
/ Cm ² , it is difficult to secure a sufficient contact pressure with the developing sleeve, and the bending elastic modulus is 100,000.
If it exceeds kg / cm ² , an appropriate spring property cannot be obtained, and it is difficult to uniformly contact the developing sleeve in the longitudinal direction.

If the creep characteristic exceeds 1.5%, there arises a problem that the contact pressure on the developing sleeve decreases during long-term use.

The thickness of the polysulfone sheet used as the developing blade supporting member 4a is preferably 0.1 mm to 5 mm. If the thickness is less than 0.1 mm, it is difficult to secure a sufficient contact pressure with the developing sleeve, and if the thickness exceeds 5 mm, an appropriate spring property cannot be obtained, and the uniform contact with the developing sleeve in the longitudinal direction is not obtained. Becomes difficult.

After bonding a member coated with nylon to urethane rubber to the above polysulfone sheet, the polysulfone sheet may be cut at a position where an edge portion of the sheet is cut off to obtain a desired dimension. A molded article formed by injection molding of a thermoplastic elastomer into the mold thus obtained may be cut at a position where an edge portion of the polysulfone sheet is cut off in the same manner as described above to obtain a desired dimension.

[0016]

EXAMPLES The present invention and examples will be described more specifically below. Example 1 A bending elastic modulus (ASTM D79) was used as the support member 4a.
0) 27000 kg / cm ² , creep characteristics (room temperature 21
0 kg / cm ² loaded, after 1000 hours) A resin plate formed by molding 0.95% polysulfone into a sheet having a thickness of 0.5 mm is previously mounted in a mold, and a thermally degraded elastomer is used as the frictional charging member 4b. Is dried at 70 ° C. for 6 hours and then molded by injection molding at a melting temperature of 250 ° C. and a mold temperature of 40 ° C. so that the thickness of the frictional charging member 4b becomes 1 mm. Molded product was obtained. Next, the molded product was cut from the edge portion of the polysulfone sheet so as to have a margin of 3 mm using an edge cutting machine driven horizontally by an air cylinder, and a developing blade 4 was formed. Example 2 Hardness 65 degrees (JIS-A) as frictional charging member 4b,
A sheet obtained by molding an ethylene adipate-based polyester urethane rubber into a sheet having a thickness of 1 mm, and applying a hot-press bonding to the polysulfone sheet of Example 1 using a member obtained by dip coating alcohol-soluble nylon (manufactured by Toray Industries, Inc.) Cutting was performed in the same manner as described above to form a developing blade 4. Comparative Example 1 A phosphor bronze plate having a thickness of 0.1 mm was used as the support member 4a, and the same member as in Example 2 was used as the frictional charging member 4b. The outer side of 5 mm was cut by using an edge cutting machine driven horizontally by an air cylinder to form a developing blade 4. Comparative Example 2 A flexural modulus (ASTM D79) was used as the support member 4a.
0) 26000 kg / cm ² , creep characteristics (room temperature 21
A developing blade 4 was prepared in the same manner as in Example 2, except that a resin plate obtained by molding 2.0% polyacetal into a sheet having a thickness of 0.5 mm was used (after loading at 0 kg / cm ² for 1000 hours).

The developing blade prepared as described above and the aluminum tube are blasted to obtain a ten-point average roughness Rz = 2.5 μm
The developing sleeve was adhered to the developing device so that the contact pressure between the developing blade and the developing sleeve was 18 g / cm, and the developing container was coated with toner and left without being developed. A sponge roller made of urethane foam, which removes the toner and returns it to the developing container, is attached.
rshot (manufactured by Canon Inc.), using a non-magnetic black toner, a streak visually observed when a solid black image is output on paper,
The presence or absence of unevenness or the like was confirmed, and an image output durability test was further performed.

As a result, in Examples 1 and 2, the durability
Although good images without streaks and unevenness were obtained up to 000 sheets, in Comparative Example 1, streaks on the image were observed, which were considered to be caused by unevenness at the edge portion of the phosphor bronze plate. Further, in Comparative Example 2, near the endurance number of 1,000 sheets, image unevenness occurred due to a decrease in contact pressure, which is considered to be caused by creep of the developing blade supporting member.

[0019]

As described above, when the developer amount regulating member of the present invention is used, an image free from streaks and unevenness can be stably obtained without being affected by the edge accuracy of the supporting member.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a shape of a developer amount regulating member of the present invention.

FIG. 2 is an explanatory diagram showing a developing device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 electrophotographic photoreceptor 2 container 3 developer carrier 4 developer amount regulating member 4 a support member 4 b friction charging member 5 sponge roller 6 toner (developer)

Claims (3)

[Claims] A container for accommodating a developer; a developing carrier for carrying the developer from the container to a developing section; and a pressure carrier on the surface of the developing carrier by pressing the developer carrier with the developer interposed therebetween. A developer amount regulating member that regulates the amount of the applied developer and imparts electric charge to the developer by triboelectric charging, wherein the supporting member of the developer amount regulating member is: In a temperature environment, ASTM D790
Flexural modulus from 15,000 to 100,000 kg / c
It is a resin material which is m ^2, and in (B) 23 ° C. temperature environment, 210 kg / cm ²
Creep characteristics after 1000 hours of application of load were 1.
A developer amount regulating member, which is a resin material that is not more than 5%, and is made of a resin material that satisfies the mechanical properties of the above (A) and (B). 2. The developer amount regulating member according to claim 1, wherein the support member of the developer amount regulating member is polysulfone. 3. A supporting member of the developer amount regulating member,
The developer amount regulating member according to claim 1, which is a polysulfone having a thickness of 0.1 mm to 5 mm.