Carrier for developing electrostatic image, developer for electrostatic image, developing device, cartridge, process cartridge, image forming method, and image forming apparatus
View Patent ↗A carrier for developing an electrostatic image, includes: magnetic core material particles and a coated layer coated on the magnetic core material particles, the coated layer containing a resin having a monomer unit represented by formula (A): wherein R 1 represents a hydrogen atom or a methyl group; R 2 to R 4 each independently represent a hydrogen atom, an alkyl group, an aryl group or an aralkyl group; R 5 independently represents an alkyl group, an aryl group or an aralkyl group; n represents an integer of from 0 to 7; and L1 represents a single bond or an alkylene group, provided that at least one of R 3 and R 4 is not a hydrogen atom.
1. A carrier for developing an electrostatic image, comprising:
magnetic core material particles; and
a coated layer coated on the magnetic core material particles,
the coated layer containing a resin having a monomer unit represented by following formula (A′):
wherein:
R 1 represents a hydrogen atom or a methyl group;
R 2 represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group;
R 6 represents an alkyl group;
R 7 to R 9 each independently represent a hydrogen atom or an alkyl group;
R 10 represents an alkyl group, an aryl group, or an aralkyl group;
L 1 represents a single bond or an alkylene group; and
content of the monomer unit represented by the formula (A′) is 10% by mol or more.
2. The carrier for developing an electrostatic image according to claim 1 , wherein the coated layer contains carbon black.
3. The carrier for developing an electrostatic image according to claim 2 , wherein a content of the carbon black in the coated layer is approximately 15.0% by mass or less based on the resin having a monomer unit represented by the formula (A′).
4. The carrier for developing an electrostatic image according to claim 1 , wherein in the formula (A′), R 2 represents a hydrogen atom or an alkyl group having from 1 to 4 carbon atoms.
5. A developer for an electrostatic image, comprising:
the carrier for developing an electrostatic image according to claim 1 , and a toner.
6. The developer for an electrostatic image according to claim 5 , wherein the toner contains a crystalline resin.
7. An image forming method comprising:
charging an image holding member;
exposing a surface of the image holding member, thereby forming an electrostatic latent image;
developing the electrostatic latent image formed on the surface of the image holding member, with a two-component developer, thereby forming a toner image;
transferring the toner image formed on the surface of the image holding member, to a surface of a transfer material; and
fixing the toner image transferred to the transfer material,
wherein the two-component developer is the developer for an electrostatic image according to claim 5 .
8. The carrier for developing an electrostatic image according to claim 1 , wherein content of the monomer unit represented by the formula (A′) is 20% by mol or more.
9. The carrier for developing an electrostatic image according to claim 8 , wherein content of the monomer unit represented by the formula (A′) is 30% by mol or more.