JP2853598B2 - Surface-treated cleaning blade, surface treatment method thereof, and image forming method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface-treated cleaning blade for use in an image forming apparatus utilizing an electrostatic recording process, such as an electrostatic copying machine, an electrophotographic printer, etc., a surface treating method thereof, and image forming. More particularly, the present invention relates to a cleaning blade surface-treated with a powder lubricant, a surface treatment method thereof, and an image forming method using the cleaning blade.

[0002]

2. Description of the Related Art A cleaning device for image formation which removes residual toner on the surface of an image carrier by pressing one edge of a cleaning blade made of an elastic material against the image carrier is widely known. In this cleaning device, in order to efficiently remove the untransferred residual toner, the pressure contact surface of the cleaning blade against the surface of the image carrier is usually adjusted so that the surface roughness is 1 μm or less. Since an appropriate pressing force is given to the cleaning blade, in the early stage of use, when the residual toner on the surface of the image carrier is started to be removed, the frictional resistance between the pressing surface of the cleaning blade and the image carrier surface increases, The turning of the cleaning blade is likely to occur, and the role as a cleaning device may be greatly reduced. Therefore, as a means for solving this problem, there has been proposed a technique of spraying and applying a fine powder lubricant particularly to the edge portion of the cleaning blade.

According to this technique, the powder lubricant exerts a lubricating action between the edge portion and the surface of the image carrier, so that the turning of the cleaning blade can be avoided. However, even if this powder lubricant is applied to the edge portion of the cleaning blade, a lot of powder lubrication is required when the cleaning blade is mounted on the cleaning device and incorporated into the image forming apparatus, or during transportation or storage. There is a problem that the cleaning agent is peeled off or scattered, and even if a copying operation is performed using the built-in image forming apparatus, the cleaning blade is turned up. Therefore, in recent years, a technique has been proposed in which a lubricant is dispersed in an organic solvent or water, applied to the surface of the cleaning blade, and then dried, as a coating method for uniformly and increasing the adhesion to the edge portion of the cleaning blade. . As such a technique, Japanese Patent Application Laid-Open No. 2-82283 proposes dispersing a powder lubricant in a volatile liquid such as Freon or alcohol and applying the powder lubricant to a cleaning blade.
Further, Japanese Patent Application Laid-Open No. 6-186897 proposes dispersing a powder lubricant in an aqueous liquid and applying the powder lubricant to a cleaning blade.

[0004]

However, in these methods, the dispersibility of the powder lubricant is low, and the powder lubricant must be applied uniformly, and a large amount of powder lubricant must be applied to suppress the turning of the cleaning blade. there were. Therefore, there has been a problem that the lubricant is easily peeled or peeled off because of being applied in a large amount. If the lubricant comes off, the cleaning blade may be turned up or other parts of the image forming apparatus may be contaminated, which may adversely affect the image quality. In addition, when an aqueous solvent is used, a surfactant is used to disperse the powder lubricant, so that the surfactant easily adheres to the image carrier, for example, the photoconductor, and the quality of the photoconductor is deteriorated. There is a problem that filming or the like by toner tends to occur.
In addition, it is required that these solvents be quick-drying, have low flammability and have no toxicity, and it is difficult to find a solvent that satisfies these conditions. In addition, solvents such as chlorofluorocarbon have a serious problem such as ozone damage, and their use is required to be avoided.

The present invention has been made to solve the above problems. That is, the object of the present invention is:
It is an object of the present invention to provide a method of surface-treating a cleaning blade using a powder lubricant which has good dispersibility and can obtain a lubricating effect with less powder lubricant. Still another object of the present invention is to provide a cleaning blade which uses a non-toxic and safe solvent, is quick-drying and has excellent workability, and can efficiently remove residual toner at a level equivalent to or better than conventional techniques. To provide a surface treatment method. It is another object of the present invention to provide a surface-treated cleaning blade which does not cause powder peeling during transportation, and an image forming method using the same.

[0006]

SUMMARY OF THE INVENTION The above objects of the present invention are as follows.
This can be achieved by applying a lubricant dispersion in which a powder lubricant is dispersed in a fluorine-based inert liquid having a surface tension of 8 to 18 dynes / cm to a cleaning blade, and then drying the volatile liquid.

[0007] That is, the surface treatment method of cleaning blade of the present invention, the portion to be pressed against the image bearing member cleaning blade, the surface tension of the powder lubricant 8 × 10 ^-5 to 18 × 10 ^{- The} method is characterized in that a lubricant dispersion liquid dispersed in a fluorine-based inert liquid of ⁵ N / cm is applied and dried. A cleaning blade for an image forming apparatus according to the present invention is characterized in that a surface treatment is performed by applying the above-mentioned lubricant dispersion and drying it. Further, the image forming method of the present invention includes a step of forming a toner image on an image carrier, a step of transferring the toner image onto a transfer body, and a step of removing residual toner on the image carrier. Further, in the step of removing the residual toner, the surface-treated cleaning blade is used.

Hereinafter, the present invention will be described in detail.
In the present invention, the cleaning blade to be surface-treated is usually a plate-shaped form obtained from a polymer compound, particularly a polymer elastic body, and is not particularly limited as long as it is a known one. However, diene rubbers such as butadiene rubber and isoprene rubber, and synthetic rubbers such as polyurethane rubber can be used, and it is particularly preferable to use polyurethane rubber. A conventional compounding agent may be added to these polymer compounds. In that case, a silicone oil or a fluorine-based surfactant can be used. Further, fine particles such as silicone resin and silica may be blended.

In the present invention, the cleaning blade is subjected to a surface treatment using a powder lubricant at a portion to be brought into pressure contact with the image bearing member. Examples of the powder lubricant include an acrylic resin, polystyrene, and polyfluoride. Preferred are resin fine powders such as toner containing vinylidene and a binder resin. Acrylic resin fine powder is particularly preferable because it has a friction reducing effect and does not adversely affect a cleaning blade, an image carrier (for example, a photoconductor), a toner, or the like. As the acrylic resin fine powder, an acrylate polymer and a methacrylate polymer are used, and polymethyl methacrylate is particularly preferable. The use of the acrylic resin fine powder is preferable because electric charge is less likely to be generated when friction is caused between the cleaning blade and the image bearing member, and acts to prevent electrostatic memory of the photosensitive member. The shape of the powder lubricant is particularly preferably spherical. The average particle size of the powder lubricant is preferably in the range of 0.05 to 5 μm, particularly 0.1 to 2 μm.

In order to perform a surface treatment using the above-mentioned powder lubricant, the surface tension of the powder lubricant is set to 8 × 10 ^{−5 to} 18 × 10 ⁻⁵ N.
/ Cm is dispersed in a fluorine-based inert liquid to prepare a lubricant dispersion, which is applied to a portion to be pressed against the image carrier. In the present invention, the surface tension of the fluorine-based inert liquid is 8 × 10 ^{-5 to} 18 × 10 ^-5 N / cm, and in particular, 10 × 10 ^{-5 to} 15 × 10 ^-5 N
The use of a fluorine-based inert liquid in the range of / cm is preferred.
By using the fluorine-based inert liquid in the above range, the dispersion of the powder lubricant becomes good, and the film forming property at the time of application becomes good. This is presumably because the surface tension is relatively low, so that the surface wettability increases and the contact angle decreases. Further, the surface tension is 18 × 10 ⁻⁵ N / c.
m, the dispersibility of the powder lubricant is reduced, while those lower than 8 × 10 ⁻⁵ N / cm are easily vaporized and difficult to handle at room temperature. Become.

In the present invention, the fluorine-based inert liquid having a surface tension of 8 × 10 ^{−5 to} 18 × 10 ⁻⁵ N / cm includes:
Fluorine-containing hydrocarbon derivatives having 5 to 8 carbon atoms are preferably used. Specifically, Fluorinert (C ₅ F ₁₂ ) (surface tension 10 × 10 ⁻⁵ N / cm), C ₅ F ₁₁ NO (surface tension 13 × 10 ⁻⁵ N / cm), C ₆ F ₁₄ (surface tension 12x
10 ⁻⁵ N / cm), C ₇ F ₁₆ (surface tension 13 × 10 ⁻⁵ N)
/ Cm), C ₈ F ₁₈ (surface tension 15 × 10 ⁻⁵ N / cm)
And the like are preferred. These solvents are
It is quick-drying and harmless to humans, has no adverse effects on the cleaning blade, image carrier (photoreceptor), toner, etc., has zero ozone depletion potential, and has the advantage of not adversely affecting the environment. ing.

When a lubricant dispersion is prepared by dispersing the powder lubricant in the fluorine-based inert liquid, the powder lubricant and the fluorine-based inert liquid are mixed in a weight ratio of 1:10. ~
The ratio may be 1:80. More preferably, 1:20
It mix | blends in the range of ~ 1: 60. When the compounding ratio of the powder lubricant to the fluorine-based inert liquid is smaller than the above range,
The lubricant is peeled off from the cleaning blade by transportation,
If it is large, the cleaning blade will be turned up. The mixture thus mixed is continuously dispersed by the stirrer over 1 minute to 10 minutes by the ultrasonic dispersion device. As a result, a lubricant dispersion in which uniform dispersion is maintained is obtained, and it is possible to apply the lubricant uniformly and stably to the edge portion of the cleaning blade.

The lubricant dispersion obtained as described above can be applied by a known method such as a spray coating method, a roll coating method or a brush coating method. The amount of the lubricant dispersion applied is 1.0 × 10 ⁻³ to 1.0 × 10 ^−3.
ml / cm ² , more preferably 8.4 × 10 ^{−3 to} 3.
0 × 10 ⁻² ml / cm ² , and further, 1.0 × 10 ⁻² to
A range of 2.0 × 10 ⁻² ml / cm ² is preferably used.

After being applied to the edge of the cleaning blade, the volatile liquid is removed by drying. The drying can be performed by natural drying or air drying at room temperature. As a result, the powder lubricant uniformly and firmly adheres to the surface of the cleaning blade, and the surface-treated cleaning blade of the present invention is obtained.

Next, an image forming method using the above-described surface-treated cleaning blade of the present invention will be described. In the present invention, a known process is employed for forming a toner image on the image carrier. As the image carrier, any material can be used as long as it can carry an electrostatic latent image, such as an electrophotographic photosensitive member and a dielectric recording material. After an electrostatic latent image is formed on these image carriers by a known method, development is performed using toner to form a toner image. The formed toner image is then transferred onto a transfer body such as paper by a known method, and the transferred toner image is then fixed. On the other hand, the toner remaining on the image carrier is removed in the step of removing the residual toner. In the present invention, the above-mentioned surface-treated cleaning blade is used as the cleaning blade. This makes it possible to form a good image without turning over the cleaning blade for a long period of time.

[0016]

【Example】

Example 1 A polyurethane rubber blade having a total length of 237.4 mm and a thickness of 1.5 mm was used as a cleaning blade.
Spherical polymethyl methacrylate having an average particle size of 0.5 μm (average molecular weight: about 400,000) was used as a powder lubricant.
The amount of the powder lubricant used per cleaning blade is 7.14 × 10 ⁻³ g (amount applied per unit area: 7.5)
× 10 ^-4 g / cm ² ). The powder of polymethyl methacrylate was mixed with C ₆ F ₁₄ at a weight ratio of 1:10, respectively.
Compounded and dispersed at 1:25, 1:40, 1:60, and 1:80. A certain amount of the obtained lubricant dispersion liquid was sucked up by a pump, and the lubricant dispersion liquid was dripped from the tip of the nozzle as a droplet onto the edge portion of the cleaning blade and applied. Then, it was air-dried at room temperature to obtain a surface treatment cleaning blade. In all cases obtained as described above, the torque value generated between the cleaning blade and the image carrier (photoconductor) is:
It was smaller than when a conventionally known cleaning blade was used, and the effect with less lubricant was recognized. Also,
The lubricant was uniformly applied to the applied portion. further,
In the vibration / drop test and the transportation test, the lubricant did not peel off nor scattered.

Comparative Example 1 The same polymethyl methacrylate powder as used in Example 1 was used as the powder lubricant, and the cleaning blade sprayed on the surface as it was was frequently turned up. Therefore, the powder of polymethyl methacrylate had to be sprayed on the image carrier. Comparative Example 2 The same polymethyl methacrylate powder as in Example 1 was used,
When dispersed in Freon 113 (surface tension: 19 × 10 ⁻⁵ N / cm), the dispersibility was insufficient, and unevenness of the lubricant occurred in the applied layer during application, and the lubricant was peeled off. Comparative Example 3 When a cleaning blade sprayed on the surface of polyvinylidene fluoride powder (average particle size: 0.5 μm) as it was was used, the turning of the cleaning blade frequently occurred. Therefore, polyvinylidene fluoride powder must be sprayed on the image carrier. Even then, the torque was higher than that of the present invention.

Example 2 The cleaning blade subjected to the surface treatment in Example 1 was incorporated in an image forming apparatus (PR-1000, manufactured by NEC). Copying was performed using this image forming apparatus. That is, a toner image having a styrene-acrylic binder resin was formed on an image carrier made of an organic photoreceptor, and then transferred to transfer paper to remove residual toner. As a result, there was no turning of the cleaning blade, the residual toner was satisfactorily removed from the beginning, and no cleaning failure occurred on many sheets.

[0019]

According to the surface treatment method of the present invention having the above-described structure, a small amount of powder lubricant is uniformly and firmly adhered to the edge portion of the cleaning blade. Also,
Since a fluorine-based inert liquid having a surface tension of 8 × 10 ^{−5 to} 18 × 10 ⁻⁵ N / cm is used, it is quick-drying and does not require forced drying means such as an aqueous solution. And complete, with excellent workability and economy. In addition, the cleaning device provided with the cleaning blade having a surface treatment according to the present invention requires a small amount of powder lubricant to be firmly adhered to the edge portion of the cleaning blade. During cleaning and transportation, the lubricant is prevented from peeling and scattering from the surface of the cleaning blade, and good lubricity is maintained. As a result, even when the cleaning blade is pressed against the image carrier and the image carrier is rotated, the cleaning is performed. It is possible to reliably remove the residual toner remaining on the surface of the image carrier for a long time without causing the blade turning-up phenomenon. Further, it is possible to provide a cleaning device having an excellent ability to remove residual toner and the like. Further, according to the image forming apparatus of the present invention, it is possible to obtain an excellent image over a long period of time.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yusaku Shibuya 1600 Takematsu, Minamiashigara-shi, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (56) References JP-A-3-158888 (JP, A) JP-A-2-82283 ( JP, A) JP-A-3-10784 (JP, A) JP-A-3-10784 (JP, A) JP-A-7-181862 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , (DB name) G03G 21/10 -21/12

Claims (7)

(57) [Claims] 1. A powder lubricant having a surface tension of 8 × 10 ^{-5 to} 1 is applied to a portion of a cleaning blade which is pressed against an image carrier.
A surface treatment method for a cleaning blade for an image forming apparatus, comprising applying a lubricant dispersion liquid dispersed in a fluorine-based inert liquid of 8 × 10 ⁻⁵ N / cm and drying. 2. The surface treatment method for a cleaning blade for an image forming apparatus according to claim 1, wherein the fluorine-based inert liquid is a fluorine-containing hydrocarbon derivative having 5 to 8 carbon atoms. 3. The fluorine-based inert liquid has a surface tension of 10 ×.
10 ^-5 to 15 × 10 ^-5 N / cm surface treatment method of a cleaning blade for an image forming apparatus according to claim 1, characterized in that. 4. The method according to claim 1, wherein the weight ratio of the powder lubricant to the fluorine-based inert liquid is from 1:10 to 1:80. 5. The surface treatment method for a cleaning blade for an image forming apparatus according to claim 1, wherein the powder lubricant is resin fine particles. 6. A powder lubricant having a surface tension of 8 × 10 ^{-5 to} 1 is applied to a portion of the cleaning blade which is pressed against the image carrier.
A cleaning blade for an image forming apparatus, which has been surface-treated by applying and drying a lubricant dispersion liquid dispersed in a fluorine-based inert liquid of 8 × 10 ⁻⁵ N / cm. 7. An image forming method comprising: forming a toner image on an image carrier, transferring the toner image onto a transfer member, and removing residual toner on the image carrier. An image forming method, wherein the step of removing is performed using the cleaning blade according to claim 6.