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. 17, 2002
Filed:
Apr. 24, 2001
Applicant:
Inventors:
Ryuzo Ueno, Nishinomiya, JP;
Masaya Kitayama, Takarazuka, JP;
Hiroyuki Kato, Kawanishi, JP;
Ryoichi Otsuka, Kobe, JP;
Assignee:
Kabushiki Kaisha Ueno Seiyaku Oyo Kenkyujo, Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C30B 7/00 ; C30B 2/102 ; C30B 2/806 ;
U.S. Cl.
CPC ...
C30B 7/00 ; C30B 2/102 ; C30B 2/806 ;
Abstract
A process for manufacturing columnar crystals of 6-hydroxy-2-naphthoic acid comprising the steps of, dissolving crude 6-hydroxy-2-naphthoic acid product in an aqueous solvent, adding crystalline 3-hydroxy-2,7-naphthoic acid or columnar crystals as seed crystals, and cooling the mixture to precipitate the desired crystals. The present invention further provides columnar crystals of 6-hydroxy-2-naphthoic acid which have X-ray diffraction peaks 2&thgr; in 16.8-17.8 and/or 21.3-22.3.