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:
Oct. 27, 2015
Filed:
Sep. 05, 2011
Masami Matsumoto, Okayama, JP;
Hiroaki Shigeta, Okayama, JP;
Nozomi Nakagawa, Okayama, JP;
Ikutaro Kuzuhara, Kanagawa, JP;
Masami Matsumoto, Okayama, JP;
Hiroaki Shigeta, Okayama, JP;
Nozomi Nakagawa, Okayama, JP;
Ikutaro Kuzuhara, Kanagawa, JP;
MITSUBISHI GAS CHEMICAL COMPANY, INC., Tokyo, JP;
Abstract
The present invention provides a method for producing ditrimethylolpropane which is characterized by the following (1) and (2): (1) a distillation still residue separated from purified trimethylolpropane is subjected to re-distillation under specific conditions to obtain a ditrimethylolpropane-containing solution having given contents of bis-TMP and tri-TMP; and (2) when subjecting the ditrimethylolpropane-containing solution to crystallization with an organic solvent, the crystallization is initiated under pressure at a temperature exceeding a boiling point of the organic solvent as measured under normal pressures, and the resulting crystallization product solution is cooled at a temperature drop rate of 2° C./min or less. According to the above method, it is possible to produce a high-purity ditrimethylolpropane from a distillation still residue obtained upon production of trimethylolpropane in a simple, industrially useful manner.