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:
Jun. 26, 2001
Filed:
Jun. 25, 1998
Applicant:
Inventors:
Assignee:
Nippon Shokubai Co LTD, Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C 5/702 ;
U.S. Cl.
CPC ...
C07C 5/702 ;
Abstract
A method for recovering acrylic acid from high boiling impurities containing acrylic acid dimer, acrylic acid and maleic acid at high efficiency with stability which includes the steps of (1) introducing said high boiling impurities containing acrylic acid dimer, acrylic acid and maleic acid into an acrylic acid recovery column, distilling acrylic acid from the column top and recovering the same, (2) introducing bottom liquid A from said acrylic acid recovery column into a pyrolyzing tank to decompose the acrylic acid dimer in the bottom liquid A, and (3) recirculating at least a part of bottom liquid B from said pyrolyzing tank into the acrylic acid recovery column.
Published as:
EP0887334A1; ID20500A; CN1204639A; JPH1112222A; KR19990007242A; TW381078B; US6252110B1; EP0887334B1; DE69807157D1; DE69807157T2; KR100388119B1; CN1134404C; MY120539A;