JP-2026075867-A - conductive roller

Abstract

[Problem] To provide a conductive roller that can reduce frictional force without drastically increasing the hardness of the surface layer. [Solution] The present invention provides a conductive roller 1 comprising a shaft 2, an elastic layer 3 provided on the outer circumference of the shaft 2, and a surface layer 4 provided on the outer circumference of the elastic layer 3, wherein the surface layer 4 has an area ratio of 40% or more of the histogram portion where the adhesion force to the entire histogram measured using an atomic force microscope is 6 nN or less, and an area ratio of 30% or more of the histogram portion where the adhesion force to the entire histogram is 8 nN or more. [Selection Diagram] Figure 1

Inventors

• 藤田 圭一郎
• 森 雄作

Assignees

• 信越ポリマー株式会社

Dates

Publication Date

20260511

Application Date

20241023

Claims (5)

1. The device comprises a shaft, an elastic layer provided on the outer circumference of the shaft, and a surface layer provided on the outer circumference of the elastic layer. A conductive roller wherein the surface layer has an area ratio of 40% or more of the histogram portion where the adhesion force to the entire histogram, as measured using an atomic force microscope, is 6 nN or less, and an area ratio of 30% or more of the histogram portion where the adhesion force to the entire histogram is 8 nN or more.
2. The conductive roller according to claim 1, wherein the surface layer contains a silicone urethane resin.
3. The conductive roller according to claim 1, wherein the surface layer has a sea-island structure.
4. The conductive roller according to claim 1, wherein the surface resin composition for forming the surface layer contains an acrylic or fluorine-based reactive additive having a graft structure.
5. The conductive roller according to claim 1, wherein the static friction coefficient of the surface layer is 0.8 or more and 1.2 or less.

Description

This invention relates to a conductive roller. Developing rollers used in image forming devices such as photocopiers, printers, and facsimile machines employing electrophotography have the function of transporting toner to an image carrier on which an electrostatic latent image has been formed. In recent years, with the miniaturization of image forming devices, the motors that rotate the rollers have also become smaller. To reduce the load on these small motors, it is necessary to reduce the frictional force (adhesion force) on the surface of the developing roller. For example, Patent Document 1 discloses a cleaning blade in which the adhesion force of the surface near the contact portion, including at least the portion that contacts the image carrier, is set to 2.5 nN or more and 3.9 nN or less, thereby improving cleaning performance. Japanese Patent Publication No. 2007-102129 This is a perspective view showing one embodiment of the conductive roller of the present invention.This is a histogram showing the adhesion force of the surface layer of the developing roller in Example 1.This is an atomic force microscope image of the surface layer of the developing roller in Example 1.This is a histogram showing the adhesion force of the surface layer of the developing roller in Example 2.This is an atomic force microscope image of the surface layer of the developing roller in Example 2.This is a histogram showing the adhesion force of the surface layer of the developing roller in Example 3.This is an atomic force microscope image of the surface layer of the developing roller in Example 3.This is a histogram showing the adhesion force of the surface layer of the developing roller in Comparative Example 1.This is an atomic force microscope image of the surface layer of the developing roller in Comparative Example 1. The embodiments of the present invention will be described in detail below with reference to the drawings. [Conductive roller] As shown in Figure 1, the conductive roller 1 of the present invention comprises a shaft 2, an elastic layer 3 provided on the outer circumference of the shaft 2, and a surface layer 4 provided on the outer circumference of the elastic layer 3. The surface layer 4 has an area ratio of 40% or more of the histogram portion where the adhesion force to the entire histogram, as measured using an atomic force microscope, is 6 nN or less, and an area ratio of 30% or more of the histogram portion where the adhesion force to the entire histogram is 8 nN or more. The following describes each component. (Axis) The shaft 2 can preferably be a conventionally known conductive roller shaft that is electrically conductive. The shaft 2 is preferably made of at least one metal selected from the group consisting of, for example, iron, aluminum, stainless steel, and brass. A shaft 2 made of such a metal is generally also known as a "core metal". The shaft 2 may contain an insulating resin. The insulating resin may be, for example, a thermoplastic resin or a thermosetting resin. The shaft 2 may comprise, for example, a core made of an insulating resin and a plating layer provided on this core. Such a shaft 2 can be obtained, for example, by plating a core made of an insulating resin to make it conductive. The shaft 2 is preferably a core metal in order to obtain good conductivity. The shape of the shaft 2 is preferably, for example, rod-shaped or tubular. The cross-sectional shape of the shaft 2 may be, for example, circular, elliptical, or non-circular, such as a polygon. The outer surface of the shaft 2 may be treated with cleaning, degreasing, priming, or other processes to improve adhesion with the elastic layer 3. The axial length of the shaft 2 is not particularly limited and may be adjusted as appropriate depending on the configuration of the image forming apparatus in which it is installed. For example, when the printing target is A4 size, the axial length of the shaft 2 is preferably 250 mm to 320 mm, and more preferably 260 mm to 310 mm. Similarly, the diameter of the shaft 2 (diameter of the circumscribed circle) is not particularly limited and may be adjusted as appropriate depending on the configuration of the image forming apparatus in which it is installed. For example, the outer diameter of the shaft 2 (diameter of the circumscribed circle) is preferably 4 mm to 14 mm, and more preferably 6 mm to 10 mm. (Elastic layer) The elastic layer 3 is formed by heat-curing a rubber composition on the outer surface of the shaft 2. The rubber composition for forming the elastic layer 3 preferably contains rubber, a conductivity imparting agent, and various additives, if desired. Examples of rubbers in the rubber composition include silicone or silicone-modified rubber, nitrile rubber, ethylene propylene rubber (including ethylene propylene diene rubber), styrene-butadiene rubber, butadiene rubber, isoprene rubber, natural rubber, acrylic rubber, chloroprene rubber, butyl rubber, epichlorohydrin