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:
Sep. 10, 2002
Filed:
Jan. 28, 2000
Applicant:
Inventors:
Shuhei Yada, Tokyo, JP;
Masahiko Yamagishi, Mie, JP;
Kouji Kasamatsu, Mie, JP;
Yasuyuki Sakakura, Mie, JP;
Kiyoshi Takahashi, Mie, JP;
Assignee:
Mitsubishi Chemical Corporation, Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07C 5/121 ; C07C 5/1235 ;
U.S. Cl.
CPC ...
C07C 5/121 ; C07C 5/1235 ;
Abstract
A method for purifying acrylic acid, which comprises carrying out dehydration distillation of an aqueous solution of acrylic acid by means of a dehydration column, wherein a distillation column having a theoretical plate number of at least 3 plates is used as the dehydration column, and the operational temperature of a site corresponding to the second theoretical plate is adjusted to be from 50 to 78° C.