US 11,914,326 B2
Magnetic toner
Masami Tsujihiro, Osaka (JP)
Assigned to KYOCERA Document Solutions Inc., Osaka (JP)
Filed by KYOCERA Document Solutions Inc., Osaka (JP)
Filed on May 21, 2021, as Appl. No. 17/327,359.
Claims priority of application No. 2020-090753 (JP), filed on May 25, 2020.
Prior Publication US 2021/0364940 A1, Nov. 25, 2021
Int. Cl. G03G 9/087 (2006.01); C08G 63/16 (2006.01); C08G 63/195 (2006.01); G03G 9/083 (2006.01)
CPC G03G 9/08755 (2013.01) [C08G 63/16 (2013.01); C08G 63/195 (2013.01); G03G 9/083 (2013.01); G03G 9/0874 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A positively chargeable magnetic toner comprising toner particles, wherein
the toner particles each include a toner mother particle including a polyester resin domain, a vinyl resin domain, and a magnetic powder,
a vinyl resin constituting the vinyl resin domain includes a repeating unit having a non-ring-opened oxazoline group,
a polyester resin constituting the polyester resin domain includes a repeating unit derived from tri- or higher-basic carboxylic acid,
the repeating unit derived from the tri- or higher-basic carboxylic acid has a content ratio to all repeating units derived from carboxylic acid in the polyester resin of at least 0.5% by mole and no greater than 1.5% by mole,
an area rate of an area in which the vinyl resin domain is exposed in a surface area of the toner mother particle is at least 0.02% and no greater than 1.00%, and
the magnetic toner is used as a one-component developer.