Magnetic carrier, two-component developer, and replenishment developer

A two-component developer comprising a magnetic carrier and toner, wherein

• the magnetic carrier comprises:
• 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

A replenishment developer comprising a magnetic carrier, wherein

• the 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