Electrophotographic developer, production process thereof and image forming process
AssigneeZeon Corporation
InventorsTakashi Iga, Kojiro Masuo, Kazuhiro Sato
Life of this patent
Estimating the term…
Abstract
An electrophotographic developer comprising at least one element selected from the group consisting of boron and phosphorus in a content of 0.1 to 100 ppm, which the developer is excellent in flowability and shelf stability, does not give image defects such as occurrence of white stripes and attains almost constant image quality even when the ambient conditions including temperature and humidity fluctuate. A production process of a polymerized toner used in the developer, a production process of the developer, and an image forming process.
Claims6
A process for producing a polymerized toner, comprising the step of subjecting a monomer composition comprising a polymerizable monomer and a colorant to suspension polymerization in an aqueous dispersion medium containing a dispersion stabilizer to form colored polymer particles, wherein at least one water-soluble compound selected from the group consisting of water-soluble boron compounds and water-soluble phosphorus compounds is caused to exist in the aqueous dispersion medium to conduct the suspension polymerization,
- wherein the production process comprises forming colored polymer particles (A1) by the step of subjecting a monomer mixture containing a polymerizable monomer and a colorant to suspension polymerization and then adding the step of polymerizing a polymerizable monomer, which is capable of forming a polymer having a glass transition temperature higher than that of the polymer component making up the colored polymer particles (A1), in the presence of the colored polymer particles (A1) to form a layer of the polymer having a higher glass transition temperature on the surfaces of the colored polymer particles (A1), thereby forming a polymerized toner composed of core-shell type colored polymer particles (A2).
Dependencies are inferred from the claim text.