Sumitomo Riko Company Limited

Kosuke Minematsu

Yutaka Kadoshima

Kentaro Imai

Yasunori Nimura

Kadai Takeyama

Satoshi Tatsumi

A conductive roll for electrophotographic device is provided. The conductive roll for electrophotographic deviceincludes a shaft bodyand a non-foamed elastic body layerformed on an outer periphery of the shaft body. The elastic body layeris made of a cross-linked product of a silicone rubber composition containing the following (a) to (d), and a secondary particle diameter of the following (d) in the elastic body layeris within a range of 100 to 500 nm. (a) is an organopolysiloxane, (b) is a crosslinking agent, (c) is a microcapsule catalyst made of fine resin particles which encapsulate a crosslinking catalyst by a resin other than a silicone resin, and (d) is silica with a BET specific surface area of 70 to 350 m/g.

Conductive roll for electrophotographic device

Provided is a development roll for electrophotography devices in which image defects are suppressed and which achieve both maintenance of high charging properties and discharging properties. The development roll is provided with a shaft member, an elastic substance layer formed on the outer circumference of the shaft member, an intermediate layer formed on the outer circumference of the elastic substance layer, and a surface layer formed on the outer circumference of the intermediate layer. The volume resistivity of the surface layeris within the range of 1.0&#xd7;10to 1.0&#xd7;10&#x3a9;&#xb7;cm, and the volume resistivity of the intermediate layeris within the range of 1.0&#xd7;10to 1.0&#xd7;10&#x3a9;&#xb7;cm.

Development roll for electrophotography device

Provided is a developing roll (R) with which it is possible to suppress toner stress in a low-temperature and low-humidity environment. A developing roll (R) for an electrophotographic device has a surface layer (). In a surface hardness histogram () of the surface layer () measured by using an atomic force microscope (AFM), the surface hardness (H) at the top peak (P) is in the range of 10-55 MPa, and the area ratio (S) of the histogram portion corresponding to a surface hardness of 45 MPa or below in relation to the entire histogram is 65% or above.

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Aichi, Japan

Kosuke Minematsu