US 10,969,705 B2Granted

Two-component developer

AssigneeCanon Kabushiki Kaisha

InventorsKazuhisa Shirayama, Hayato Ida, Takeshi Hashimoto, Kentaro Kamae, Takashi Matsui

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Abstract

Provided is a two-component developer has a toner including a toner particle including a binder resin, and a magnetic carrier, wherein the binder resin includes a polymer A having a first monomer unit derived from a first polymerizable monomer, and a second monomer unit derived from a second polymerizable monomer different from the first polymerizable monomer, the first polymerizable monomer is a specific (meth)acrylic acid ester, a content and an SP value of the first and second monomer units in the polymer A fall within respective specific ranges, the magnetic carrier has a magnetic core and a coating resin of the surface of the magnetic core, the coating resin includes a polymer B having monomer units (a) and (b), each SP value of the monomer units (a) and (b) is a specific value.

Claims23

Dependent claims

A two-component developer, comprising:

a toner including a toner particle that includes a binder resin including a polymer A having a first monomer unit derived from a first polymerizable monomer, and a second monomer unit derived from a second polymerizable monomer that is different from the first polymerizable monomer, the first polymerizable monomer being at least one member selected from the group consisting of (meth)acrylic acid esters having a C18-36 alkyl group;
and
a magnetic carrier having a magnetic core with a coating resin on a surface of the magnetic core, the coating resin including a polymer B having a monomer unit (a) derived from a polymerizable monomer (a), and a monomer unit (b) derived from a polymerizable monomer (b) that is different from polymerizable monomer (a), wherein
a content of the first monomer unit in the polymer A is 5.0 to 60.0 mol % based on the total number of moles of all the monomer units in polymer A,
a content of the second monomer unit in the polymer A is 20.0 to 95.0 mol % based on the total number of moles of all the monomer units in polymer A,
3.00≤(SP21−SP11)≤25.00 and 21.00≤SP21
when SP11 (J/cm3)0.5 is an SP value of the first monomer unit and SP21 (J/cm3)0.5 is an SP value of the second monomer unit, and
20.30≤SP(a)≤22.00 and 19.00≤SP(b)≤20.20
when SP(a) (J/cm3)0.5 is an SP value of monomer unit (a) and SP(b) (J/cm3)0.5 is an SP value of monomer unit (b).

6 more elements

A two-component developer, comprising:

a toner including a toner particle that includes a binder resin including a polymer A that is a polymer derived from a composition containing a first polymerizable monomer, and a second polymerizable monomer that is different from the first polymerizable monomer, the first polymerizable monomer being at least one member selected from the group consisting of (meth)acrylic acid esters having a C18-36 alkyl group;
and
a magnetic carrier having a magnetic core and a coating resin of the surface of the magnetic core, the coating resin including a polymer B having a monomer unit (a) derived from a polymerizable monomer (a), and a monomer unit (b) derived from a polymerizable monomer (b) different from the polymerizable monomer (a), wherein
a content of the first polymerizable monomer in the composition is 5.0 to 60.0 mol % based on the total number of moles of all polymerizable monomers in the composition,
a content of the second polymerizable monomer in the composition is 20.0 to 95.0 mol % based on the total number of moles of all polymerizable monomers in the composition,
0.60≤(SP22-SP12)≤15.00 and 18.30≤SP22
when SP12 (J/cm3)0.5 is an SP value of the first polymerizable monomer and SP22 (J/cm3)0.5 is an SP value of the second polymerizable monomer, and
20.30≤SP(a)≤22.00 and 19.00≤SP(b)≤20.20
when SP(a) (J/cm3)0.5 is an SP value of monomer unit (a) and SP(b) (J/cm3)0.5 is an SP value of monomer unit (b).

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/438,544Filed 12 Jun 2019
Priority: JP JP2018-11310513 Jun 2018
Published: US 2019/0384202 A119 Dec 2019
Granted: 6 Apr 2021
Term ends: Not estimatedThe source records don’t support an estimate.

Classification20 codes

G03G 9/1075
Having magnetic components: structural characteristics of the carrier particles, e.g. shape or crystallographic structure
C08F 218/08
Vinyl esters: vinyl acetate
C08F 220/46
Acrylonitrile: with carboxylic acids, sulfonic acids or salts thereof
C08F 220/68
Monocarboxylic acids having ten or more carbon atoms; Derivatives thereof: esters