Charging roller, process cartridge and image forming apparatus

A charging roller and image carrier technology, which can be used in corona discharge devices, electric recording technology using charge patterns, equipment for electric recording technology using charge patterns, etc., and can solve the problems of ion conductive agent leakage, etc.

Inactive Publication Date: 2007-10-31

SHARP KK

9 Cites 5 Cited by

AI-Extracted Technical Summary

Problems solved by technology

[0007] However, when the surface-treated charging rollers described in Documents 2 to 9 are stored for a long period of time in a hig...

Method used

Wherein, in the item of photoreceptor pollution in above-mentioned table 1, " ○ " expression all does not find the image defect that photoreceptor pollution causes from the first sheet, " △ " expression finds that the first or second sheet exists Image defects caused by photoreceptor contamination disappeared afterward, and "×" indicates that image defects caused by photoreceptor contamination were found until the third sheet. Also, the ion conductive agent adhering to the photoreceptor is grabbed by the cleaning blade by the rotation of the photoreceptor, so as the number of sheets overlaps, image defects are reduced. Therefore, "◯" means that photoreceptor contamination did not occur, "△" means that photoreceptor contamination slightly occurred, and "×" means that photoreceptor contamination was conspicuous.

[0067] Furthermore, in order to prevent the ion cond...

Abstract

The invention provides a charging roller which includes a rubber member with a surface subjected to a hardening treatment using a solvent containing at least an isocyanate compound, and which prevents leakage of an ionic conductive agent even if the charging roller is placed in high-temperature and high-humidity environment for a long period of time. The charging roller is made by forming a rubber layer on a metal core. The rubber layer is an epichlorohydrin based rubber base material to which the ionic conductive agent is added, and is subjected to a surface treatment by applying a solution containing the isocyanate compound thereon and heating it. The surface treatment is carried out under such conditions that a coefficient of dynamic friction at a contact portion between the rubber layer and a photoreceptor becomes 0.4 or less.

Application Domain

Electrographic process apparatusCorona discharge

Technology Topic

SolventIon +9

Image

Examples

Experimental program(12)
Comparison scheme(7)

Example Embodiment

[0109] (Example 1-1)

[0110] The calcination temperature in the above calcination treatment is set to "high" among the three stages consisting of "high", "standard", and "low". The firing time is set to "long" among the three stages consisting of "long", "standard", and "short". The concentration of the surface treatment liquid is set to "high" among the three stages consisting of "high", "standard", and "low".

[0111] The charging roller 2 subjected to the surface treatment under the above conditions was brought into contact with the lubricant-coated photoreceptor 1 and stored for a long time. As a result, no image defects caused by contamination of the photoreceptor were found from the first sheet. In addition, the coefficient of dynamic friction between the charging roller 2 and the photoreceptor 1 is 0.25.

[0112] However, after assembling the charging roller 2 into a modified device for printing, a black stripe-shaped image defect was clearly found. It can be considered that this is because the slip of the charging roller 2 is obvious.

Example Embodiment

[0113] (Example 1-2)

[0114] The firing temperature is set to "high", the firing time is set to "long", and the concentration of the surface treatment liquid is set to "high".

[0115] The charging roller 2 subjected to the surface treatment under the above conditions was brought into contact with the photoreceptor 1 without the lubricant applied and stored for a long time. As a result, no image defects caused by contamination of the photoreceptor were found from the first sheet. In addition, the coefficient of dynamic friction between the charging roller 2 and the photoreceptor 1 is 0.25.

[0116]However, after printing with the charging roller 2, a few black stripe-like image defects were found. It can be considered that this is because the charging roller 2 slipped slightly.

Example Embodiment

[0117] (Example 1-3)

[0118] The firing temperature is set to "high", the firing time is set to "long", and the concentration of the surface treatment liquid is set to "standard".

[0119] The charging roller 2 subjected to the surface treatment under the above conditions was brought into contact with the photoreceptor 1 without the lubricant applied and stored for a long time. As a result, no image defects caused by contamination of the photoreceptor were found from the first sheet. In addition, the coefficient of dynamic friction between the charging roller 2 and the photoreceptor 1 is 0.27. Further, after printing with the charging roller 2, no image defects caused by the slip of the charging roller 2 were found.

PUM

Description & Claims & Application Information

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