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:
May. 25, 2010
Filed:
Jun. 28, 2007
Masayuki Kamikawa, Hitachinaka, JP;
Toshiaki Matsuo, Mito, JP;
Kenichiro Oka, Hitachi, JP;
Naruyasu Okamoto, Tokyo, JP;
Ryuji Kaziya, Yokohama, JP;
Masayuki Kamikawa, Hitachinaka, JP;
Toshiaki Matsuo, Mito, JP;
Kenichiro Oka, Hitachi, JP;
Naruyasu Okamoto, Tokyo, JP;
Ryuji Kaziya, Yokohama, JP;
Hitachi Plant Technologies, Ltd., Tokyo, JP;
Abstract
The object is to provide a method and apparatus for producing a polyhydroxy carboxylic acid according to which an annular dimer can be efficiently obtained in the production of polyhydroxy carboxylic acid which is small in distribution breadth of molecular weight in depolymerization and opening ring polymerization steps. There are provided a depolymerization devicewhich depolymerizes hydroxy carboxylic acid or a polycondensate thereof into an annular dimer, a upper distillation columnwhich condenses the annular dimer vaporized in the depolymerization device, and lower distillation columnwhich refluxes the annular dimer and is provided between the depolymerization deviceand the upper distillation column, said depolymerization devicehaving a polycondensate feed openingand an annular dimer discharge openingwhich are provided at a casing, a liquid film being formed inside the casingand heated by a heating part.