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:
Nov. 21, 2006
Filed:
Feb. 01, 2005
Vijai P. Gupta, Berwyn, PA (US);
Edward P. Carey, Atglen, PA (US);
Vijai P. Gupta, Berwyn, PA (US);
Edward P. Carey, Atglen, PA (US);
Lyondell Chemical Technology, L.P., Houston, unknown;
Abstract
A method for purifying N-vinyl-2-pyrrolidone (NVP) is disclosed. The method comprises crystallizing NVP in the presence of added water to produce purified NVP crystals and a mother liquor, and then isolating the purified crystals. In a preferred method, 0.5 to 4 wt. % of water based on the amount of NVP to be purified is added, and the NVP crystals are washed with additional pure NVP, preferably NVP crystal melt, to give crystals having a purity greater than 99.99%. The method provides a fast, effective way to generate and isolate pure NVP in a single-stage crystallization.