Oblon, McClelland, Maier & Neustadt, L.L.P.
Toner, developer, image forming apparatus, and process cartridge
A toner includes a polyester resin including a polyester resin component A (A) insoluble in tetrahydrofuran; and a polyester resin component B (B) soluble in tetrahydrofuran. The toner has a first glass transition temperature (Tg1st) of from 20° C. to 50° C., measured at a first temperature rising in differential scanning calorimetry (DSC), and satisfies the following formulae (1) and (2):T=1/{a/(TgA+273)+b/(TgB+273)}−273  (1)T−TgAB>30×a  (2)wherein a and b represent weight ratios of (A) and (B) to a total weight of (A) and (B), and satisfy the equation a+b=1; and TgA, TgB and TgAB represent second glass transition temperatures (Tg2nd), measured at a second temperature rising in differential scanning calorimetry, of (A), (B), and a mixture of (A) and (B), respectively.
Ricoh Company, Ltd.
G C C C C
G03G C08L C08G C08G C08G
inventional inventional inventional inventional inventional
Hiroshi Kohsuke Hideyuki Shin Suzuka Koh Shinya Tsuyoshi
Yamada Nagata Santo Hasegawa Karato Ohnuma Nakayama Sugimoto