The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 14, 1992
Filed:
Nov. 30, 1989
Tomonori Wada, Kagoshima, JP;
Nobuhiro Hirano, Osaka, JP;
Hiroshi Shimoyama, Osaka, JP;
Hideki Ota, Ikoma, JP;
Toshiro Tokuno, Takarazuka, JP;
Mita Industrial Co., Ltd., Osaka, JP;
Abstract
Disclosed a process for the preparation of polymer particles, which comprises suspending a polymerizable monomer, a radical initiator and a hardly soluble inorganic dispersant in a dispersion medium and carrying out polymerization in this state, wherein a hardly soluble inorganic dispersant, the solubility of which is changed according to the pH value in the dispersion medium and which is precipitated at a pH value within a certain pH value region of the dispersion medium, is used as the dispersant, suspension of the polymerizable monomer in the dispersion medium is carried out in the state where the dispersant is dissolved in the dispersion medium, an acid or base is then added to adjust the pH value of the dispersion medium to a predetermined level to precipitate the dispersant, and the polymerization is initiated in the state where oil drops having a fine particulate size are formed. The process is effectively utilized for obtaining a toner having good flowability and blocking resistance and excellent developing and fixing properties by using a colorant together with the polymerizable monomer.