US 12,222,678 B2
Magnetic carrier, two-component developer, and replenishment developer
Ryuji Murayama, Chiba (JP); Yuto Onozaki, Saitama (JP); Nobuhiro Yoshida, Chiba (JP); and Hironori Minagawa, Ibaraki (JP)
Assigned to CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed by CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed on Jan. 24, 2022, as Appl. No. 17/582,691.
Claims priority of application No. 2021-012504 (JP), filed on Jan. 28, 2021; and application No. 2021-213008 (JP), filed on Dec. 27, 2021.
Prior Publication US 2022/0236658 A1, Jul. 28, 2022
Int. Cl. G03G 9/113 (2006.01); G03G 9/107 (2006.01)
CPC G03G 9/1133 (2013.01) [G03G 9/1085 (2020.08)] 10 Claims
OG exemplary drawing
 
1. A magnetic carrier comprising:
a magnetic core; and
a coating resin that covers a surface of the magnetic core,
wherein:
the coating resin comprises a resin A and a resin B;
a content of the resin A is 1 to 50% by mass, and a content of the resin B is 50 to 99% by mass, with respect to the total mass of the coating resin;
the resin A has a unit Y1 represented by formula (1) and a unit Y2 represented by formula (2), and
in the resin B, a content of the unit Y2 represented by formula (2) is 0.1% by mass or less; and
when a mass of the resin A, a mass of the unit Y1 in the resin A, and a mass of the unit Y2 in the resin A are represented by X, Ma and Mb, respectively, the X, the Ma and the Mb satisfy expressions (a) and (b):
0.90≤(Ma+Mb)/X≤1.00  (a), and
1.00≤Ma/Mb≤30.0  (b),
and
when an SP value of the unit Y1 and an SP value of the resin B are represented by SPa and SPb, respectively, the SPa and the SPb satisfy expression (c):
0≤|SPa−SPb|≤2.0  (c),
wherein in formula (1),
R1 represents H or CH3, and
R2 represents a hydrocarbon group having 1 to 8 carbon atoms and optionally having a substituent, wherein the substituent is a hydroxy group or a carboxy group; and
in formula (2),
R3 represents H or CH3,
R4 represents H or CH3,
R5 represents a single bond or a hydrocarbon group having 1 to 10 carbon atoms,
R6 represents a hydrocarbon group having 1 to 10 carbon atoms,
R7 represents H, CH3 or Si(CH3)3, and
n represents an integer of 2 to 150

OG Complex Work Unit Chemistry