Magnetic carrier, two-component developer, and developer for replenishment

A two-component developer comprising:

• a magnetic carrier;
• and
• a toner,
• wherein the magnetic carrier includes a magnetic core and a coating resin configured to coat a surface of the magnetic core,
• wherein the coating resin contains a graft resin A and a graft resin B,
• wherein the coating resin
• (i) contains 1.0 mass % or more and 50.0 mass % or less of the graft resin A, and
• (ii) contains 50.0 mass % or more and 99.0 mass % or less of the graft resin B,
• wherein the graft resin A has a unit Y1 represented by formula (1) and a unit Y2 represented by formula (2),
• wherein when a mass of the graft resin A is represented by X, a mass of the unit Y1 in the graft resin A is represented by Ma, and a mass of the unit Y2 in the graft resin A is represented by Mb, Ma, Mb, and X satisfy 0.90≤(Ma+Mb)/X≤1.00 and 1.00≤Ma/Mb≤30.0, and
• wherein the graft resin B
• (i) is a comb-shaped polymer having, as a branch, at least one moiety selected from the group consisting of:
• a styrene-based polymer moiety;
• a (meth)acrylate-based polymer moiety;
• and a styrene-acrylate-based polymer moiety, and
• (ii) is free of a polysiloxane structure moiety or contains the polysiloxane structure moiety at a content of 0.1 mass % or less:
• in formula (1) or formula (2),
• R1 represents H or CH3,
• R2 represents a hydrocarbon group having 1 or more and 6 or less carbon atoms that may have a substituent, and the substituent is a hydroxy group or a carboxy group,
• R3 represents H or CH3,
• R4 represents H or CH3,
• R5 represents a single bond, or a hydrocarbon group having 1 or more and 6 or less carbon atoms,
• R6 represents a hydrocarbon group having 1 or more and 10 or less carbon atoms,
• R7 represents H, CH3, or Si(CH3)3, and
• l and m each represent an integer of 1 or more, and n represents an integer of 2 or more and 150 or less.

A developer for replenishment to be replenished into a developing unit in accordance with a reduction in toner concentration of a two-component developer in the developing unit, the developer for replenishment comprising:

• a magnetic carrier;
• and
• a toner,
• wherein the magnetic carrier includes a magnetic core and a coating resin configured to coat a surface of the magnetic core,
• wherein the coating resin contains a graft resin A and a graft resin B,
• wherein the coating resin
• (i) contains 1.0 mass % or more and 50.0 mass % or less of the graft resin A, and
• (ii) contains 50.0 mass % or more and 99.0 mass % or less of the graft resin B,
• wherein the graft resin A has a unit Y1 represented by formula (1) and a unit Y2 represented by formula (2),
• wherein when a mass of the graft resin A is represented by X, a mass of the unit Y1 in the graft resin A is represented by Ma, and a mass of the unit Y2 in the graft resin A is represented by Mb, Ma, Mb, and X satisfy 0.90≤(Ma+Mb)/X≤1.00 and 1.00≤Ma/Mb≤30.0, and
• wherein the graft resin B
• (i) is a comb-shaped polymer having, as a branch, at least one moiety selected from the group consisting of:
• a styrene-based polymer moiety;
• a (meth)acrylate-based polymer moiety;
• and a styrene-acrylate-based polymer moiety, and
• (ii) is free of a polysiloxane structure moiety or contains the polysiloxane structure moiety at a content of 0.1 mass % or less:
• in formula (1) or formula (2),
• R1 represents H or CH3,
• R2 represents a hydrocarbon group having 1 or more and 6 or less carbon atoms that may have a substituent, and the substituent is a hydroxy group or a carboxy group,
• R3 represents H or CH3,
• R4 represents H or CH3,
• R5 represents a single bond, or a hydrocarbon group having 1 or more and 6 or less carbon atoms,
• R6 represents a hydrocarbon group having 1 or more and 10 or less carbon atoms,
• R7 represents H, CH3, or Si(CH3)3, and
• l and m each represent an integer of 1 or more, and n represents an integer of 2 or more and 150 or less.