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:
Mar. 10, 1998
Filed:
Aug. 14, 1996
Idemitsu Petrochemical Co., Ltd., Tokyo, JP;
Abstract
A process for producing polymer particles from an organic solvent solution of a polymer, which includes: (a) initially introducing polymer particles into a particle producing zone, (b) introducing an organic solvent solution containing an organic solvent and having a polymer concentration of 3 to 70% by weight, onto the polymer particles which are maintained in the particle producing zone, the particle producing zone not substantially containing steam, the organic solvent solution being added in an amount of not more than 250% by weight per hour based on the amount of the polymer particles which are initially held in the particle producing zone, and stirring the polymer particles under conditions in which the organic solvent would be vaporized, (c) separately introducing a poor solvent for the polymer into the particle producing zone, the poor solvent being selected from the group consisting of benzene, toluene, xylene, pentane, hexane, octane, acetone and methyl ethyl ketone, the poor solvent being in an amount of 5 to 200% by weight based on the weight of the organic solvent in the organic solvent solution, and (d) evaporating the organic solvent and the poor solvent, while maintaining the organic solvent solution of the polymer in contact with the polymer particles which are maintained in the particle producing zone, to produce the polymer particles.