Toner and two-component developer, container therefor, and image forming apparatus
AssigneeRicoh Company, Ltd.
InventorsHiroto Higuchi, Masanori Suzuki, Hiroaki Matsuda, Akemi Sugiyama
Life of this patent
Estimating the term…
Abstract
A toner for developing electrostatic latent images contains a coloring agent, a release agent, a binder resin including a non-linear polyester resin with a hydroxyl number of 30 to 70 mgKOH/g, and a metallic compound of an aromatic oxycarboxylic acid with a central metal having a valence of 3 or more. The toner is used in combination with a carrier to prepare a two-component developer. The toner or two-component developer is held in a container. The present invention further provides an image forming apparatus equipped with the container that holds therein the above-mentioned toner or two-component developer.
Claims42
A toner for developing electrostatic latent images, comprising:
- a coloring agent,
- a release agent,
- a binder resin comprising a non-linear polyester resin with a hydroxyl number of 30 to 70 mgKOH/g, and
- a metallic compound of an aromatic oxycarboxylic acid with a central metal having a valence of 3 or more,
- wherein said binder resin further comprises:
- a linear polyester resin and
- a composite resin comprising a polyester resin and a vinyl resin, wherein said composite resin is prepared by parallel reaction of (1) a condensation polymerization of a condensation-polymerizable monomer to prepare said polyester resin and (2) an addition polymerization of an addition-polymerizable monomer to prepare said vinyl resin in the same reactor;
- and wherein said toner exhibits a peak molecular weight within a range of 1,000 to 10,000 and has a half peak width of 15,000 or less when a molecular weight distribution is determined from a soluble content in tetrahydrofuran by gel permeation chromatography.
A two-component developer comprising a toner and a carrier, said toner comprising:
- a coloring agent,
- a release agent,
- a binder resin comprising a non-linear polyester resin with a hydroxyl number of 30 to 70 mgKOH/g, and
- a metallic compound of an aromatic oxycarboxylic acid with a central metal having a valence of 3 or more,
- wherein said binder resin further comprises:
- a linear polyester resin and
- a composite resin comprising a polyester resin and a vinyl resin, wherein said composite resin is prepared by parallel reaction of (1) a condensation polymerization of a condensation-polymerizable monomer to prepare said polyester resin and (2) an addition polymerization of an addition-polymerizable monomer to prepare said vinyl resin in the same reactor;
- and wherein said toner exhibits a peak molecular weight within a range of 1,000 to 10,000 and has a half peak width of 15,000 or less when a molecular weight distribution is determined from a soluble content in tetrahydrofuran by gel permeation chromatography.
Dependencies are inferred from the claim text.