Two-component developer for developing electrostatic latent image
Provided is a two-component developer for developing an electrostatic latent image incorporating: toner particles each containing a toner mother particle having an external additive on a surface of the toner mother particle; and carrier particles each having a core material particle and a covering layer containing a resin on a surface of the core material particle, wherein the external additive contains inorganic particles; the inorganic particles are subjected to surface modification with silicone oil; a carbon content remained on a surface of the inorganic particle after the surface modification is within 3.0 to 10.0 mass %; a free carbon ratio on the surface of the inorganic particle is 70.0% or more; the carrier particles have a resistance in the range of 1.0×10 9 to 5.0×10 10 Ω·cm; and the resin in the covering layer contains a resin formed from a monomer containing an alicyclic methacrylic acid ester monomer.
1. A two-component developer for developing an electrostatic latent image comprising:
toner particles each containing a toner mother particle having an external additive on a surface of the toner mother particle; and
carrier particles each having a core material particle and a covering layer containing a resin on a surface of the core material particle,
wherein the external additive contains inorganic particles;
the inorganic particles are subjected to surface modification with silicone oil;
a carbon content remained on a surface of the inorganic particle after the surface modification is in the range of 3.0 to 10.0 mass %;
a free carbon ratio on the surface of the inorganic particle is 70.0% or more;
the carrier particles have a resistance in the range of 1.0×10 9 to 5.0×10 10 Ω·cm;
the resin in the covering layer comprises a resin formed from a monomer containing an alicyclic methacrylic acid ester monomer; and
the toner mother particle includes a binder resin containing an amorphous vinyl resin and a crystalline resin.
2. The two-component developer for developing an electrostatic latent image described in claim 1 ,
wherein the silicone oil is dimethyl silicone oil.
3. The two-component developer for developing an electrostatic latent image described in claim 1 ,
wherein the silicone oil has a kinetic viscosity in the range of 50 to 500 mm 2 /s at 25° C.
4. The two-component developer for developing an electrostatic latent image described in claim 1 ,
wherein the inorganic particles have a number average primary-particle diameter in the range of 25 to 100 nm.
5. The two-component developer for developing an electrostatic latent image described in claim 1 ,
wherein the inorganic particles are at least one of silica particles and aluminum oxide particles.
6. The two-component developer for developing an electrostatic latent image described in claim 1 ,
wherein the core material particles in the carrier particles have a resistance in the range of 8.0×10 6 to 3.0×10 8 Ω·cm.
7. The two-component developer for developing an electrostatic latent image described in claim 1 ,
wherein the carrier particles have a resistance in the range of 5.0×10 9 to 2.0×10 10 Ω·cm.
8. The two-component developer for developing an electrostatic latent image described in claim 1 ,
wherein the covering layer consists of the resin formed from a monomer containing an alicyclic methacrylic acid ester monomer.
9. The two-component developer for developing an electrostatic latent image described in claim 1 ,
wherein a content of the alicyclic methacrylic acid ester monomer that forms the covering layer is in the range of 25 to 75 mass %.