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:
Jan. 18, 2011
Filed:
Oct. 18, 2005
Hideo Suzuki, Funabashi, JP;
Takayuki Tamura, Funabashi, JP;
Hideo Suzuki, Funabashi, JP;
Takayuki Tamura, Funabashi, JP;
Nissan Chemical Industries, Ltd., Tokyo, JP;
Abstract
A process which comprises reacting a 1,2,3,4-cyclobutanetetracarboxylic-1,2:3,4-dianhydride [1] with an alcohol [2] in the presence of an acid catalyst to obtain a compound [3], isomerizing the compound [3] with a base catalyst into a compound [4], reacting the compound [4] with an organic acid to obtain a compound [5], and reacting the compound [5] with a dehydrating agent to obtain a 1,2,3,4-cyclobutanetetracarboxylic-1,3:2,4-dianhydride: wherein Rand Rare each independently hydrogen, halogeno, alkyl of 1 to 10 carbon atoms, halogenated alkyl of 1 to 10 carbon atoms, cycloalkyl of 3 to 8 carbon atoms, phenyl, or cyano; and Ris alkyl of 1 to 10 carbon atoms.