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. 11, 2002
Filed:
Jan. 03, 2001
Applicant:
Inventors:
Ryuzo Ueno, Nishinomiya, JP;
Masaya Kitayama, Takarazuka, JP;
Nobutaka Izumichi, Ashiya, JP;
Hiroyuki Kato, Kawanishi, JP;
Assignee:
Kabushiki Kaisha Ueno Seiyaku Oyo K., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C 6/334 ;
U.S. Cl.
CPC ...
C07C 6/334 ;
Abstract
The present invention provides crystalline 2-hydroxynaphthalene-3-carboxylic acid (BON) characterized in that the average particle size is equal to or more than 157 &mgr;m and the proportion of the particles of which particle size is less than 74 &mgr;m is equal to or less than 14%. The crystalline composition of the present invention can be prepared by a process comprising the step of recrystallizing BON, especially at a high temperature, or by carrying out the acid precipitation step in the method for preparing BON at a high temperature.