Sumitomo Riko Company Limited

Hiroshi Ukai

Yoshihiro Saito

Masanori Ishida

Yasuyuki Hayasaki

Takahisa Kose

Yasuhide Watanabe

Shigeki Kanda

In a charging roll, grooves regularly defining spirals are formed on an elastic body layer, with a groove width of 4 μm to 280 μm and a groove depth of 2 μm to 30 μm. On an outer peripheral surface of the elastic body layer, an area ratio between an area of a bottom surface of the groove and an area of a plane part is 0.3 to 2.4. The surface layer includes a binder polymer and a roughness forming particle. The roughness forming particle is arranged on the plane part and the groove. A surface roughness of the surface layer on the groove is 2 μm to 16 μm. A surface roughness of the entire surface layer is 5 μm to 26 μm. A thickness of the binder polymer covering the roughness forming particle on the groove is greater than that on the plane part.

Charging roll for electrophotographic apparatus

In a charging roll for electrophotographic equipment, an outer surface layer of an elastic layer includes a binder resin, large-diameter particles having an average particle diameter of 15-50 &#x3bc;m, and small-diameter particles having an average particle diameter of 3-15 &#x3bc;m, a difference in average particle diameter between the large-diameter particles and the small-diameter particles is 10-35 &#x3bc;m, the small-diameter particles are arranged in one layer in the surface layer, the average distance between the small-diameter particles is not more than 1.2 times the average particle diameter of the small-diameter particles, the thickness a of the binder resin covering the large-diameter particles is within the range of 1.5-3.5 &#x3bc;m, the thickness b of the binder resin covering the small-diameter particles is 3.0-6.0 &#x3bc;m, and the thickness b is larger than the thickness a.

Charging roll for electrophotographic equipment

There is provided a conductive roller for electrophotographic equipment in which a shaft made of core metal has excellent rust resistance. The conductive roller includes a shaft made of core metal, a protective layer formed on the outer periphery of the shaft, and a conductive rubber elastic layer formed on the outer periphery of the protective layer. In a conductive roller for electrophotographic equipment, the conductive rubber elastic layer contains a rubber containing halogen atoms, and the protective layer is formed of a crosslinked material of a composition containing a material obtained by melting and mixing the following components (a) to (c):

Conductive roller for electrophotographic equipment

A charging roll includes a shaft, an elastic body layer formed around the shaft, and a surface layer formed around the elastic body layer. The surface layer contains a binder and roughness formation particles, and has projecting sections that project outward in the radial direction farther in the portions in which the roughness formation particles are present than in the portions in which the roughness formation particles are not present. The roughness formation particles are composed of porous silica particles, and the porous silica particles have an average particle size of 5 to 50 &#x3bc;m, an oil absorbency of 200 to 500 ml/100 g, and a pore size of 5 to 20 nm.

Growing community of inventors

Aichi, Japan

Hiroshi Ukai