Patent ID: 9298119
Filing Date: 2016-03-29
CPC Classification: G03G

Claim Text:
1. A carrier, comprising: a particulate magnetic core having an average domain diameter of from 1 μm to 10 μm; and a cover layer located on a surface of the particulate magnetic core and comprising a resin and a filler, wherein: when determined from observation of cross-section of the carrier, a shape factor SF2 of the carrier is from 120 to 160; a ratio of the average domain diameter of the particulate magnetic core to a number average particle diameter of the filler is from 1:1 to 1:0.003; the number average particle diameter of the filler, which is determined from the cross-section of the carrier, is from 540 nm to 800 nm; the carrier has a core revealing rate, which is defined as a ratio of length of an uncovered surface of the magnetic core to perimeter of the magnetic core, and which is determined from the cross-section of the carrier, of from 2.5% to 9%; and an area ratio of the filler in the cover layer is from 30 to 85%, and wherein: the resin comprises a crosslinked material prepared by hydrolyzing a copolymer having the following formula (1) to generate a silanol group and then condensing a resulting hydrolyzed resin: R R R m independently represents an integer of from 1 to 8; and X and Y independently represent molar ratios of their corresponding repeating units, wherein each of X and Y is from 10% by mole to 90% by mole.