Semiconductive roller of an image-forming apparatus

A semiconductive roller, comprising:

• an elastic layer formed of a semiconductive rubber composition comprising about 50 to about 70 parts by weight of a base rubber and about 30 to about 50 parts by weight of a hydrin rubber,
• wherein an extracted amount of an epichlorohydrin (ECH) component from the elastic layer is about 2% by volume or less, wherein the extracted amount is determined based on a reduced amount of chlorine (Cl) intensity measured using X-ray fluorescence (XRF) analysis performed before and after extraction of the ECH component from the elastic layer using tetrahydrofuran (THF),
• further comprising at least one nano-scale filler having an average particle diameter of about 10 to about 100 nm and selected from the group including calcium carbonate, silica, and nano fibril cellulose (NFC),
• wherein the hydrin rubber is a copolymer comprising epichlorohydrin and at least one selected from the group including allyl glycidyl ether and ethylene oxide,
• wherein a content of epichlorohydrin is 20% or greater based on a content of the hydrin rubber,
• a complex viscosity at 100° C. is in the range of about 70,000 to about 100,000 Pa·s, and
• a Δη*/ΔT value is about 400 Pa·s/° C. or less,
• wherein ΔT is a temperature variation (in ° C.) when the temperature is changed from 60° C. to 100° C., and Δη* is a complex viscosity variation (in Pa·s) when the temperature is changed from 60° C. to 100° C. at an angular frequency of 1 rad/s,
• wherein the extracted amount of the ECH component is calculated using a calibration curve, which is obtained by the XRF analysis, indicating a correlation between concentrations (in % by volume) of epichlorohydrin (ECH) contained in a plurality of the THF solutions comprising known different concentrations of ECH and the corresponding chlorine (Cl) intensities (in cps/μA) of the plurality of the THF solutions measured by the XRF analysis.