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. 05, 2002
Filed:
Sep. 19, 2000
Toshihisa Fujitaka, Kitakyushu, JP;
Koji Hirashima, Kitakyushu, JP;
Hideki Ono, Kitakyushu, JP;
Keiichi Hayashi, Kisarazu, JP;
Nippon Steel Chemical Co., Ltd., Tokyo, JP;
Abstract
This invention relates to a method for removing unreacted monomers and other volatile matters from a polymer solution composition produced from a mixture containing an aromatic vinyl monomer, utilizes two or more flash devolatilizing vessels, and effects the removal by adjusting the solid content of the polymer solution composition at the outlet of the devolitilizer before the last-stage devolitilizer to a level in excess of 97%, adding 0.5-4 parts by weight of a foaming agent to the total polymer solution composition, passing the polymer solution composition through the last-stage devolitilizer while maintaining the pressure of the polymer solution at 10 kg/cm or more by means of a pressure controller and the temperature in the range 190-260° C., introducing the polymer solution composition to a vapor-liquid separation vessel maintained at a vacuum of 20 Torr or less, and allowing the composition to foam.