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:
May. 05, 1987
Filed:
Aug. 25, 1986
Maria A Geigel, Cupertino, CA (US);
Chester W Marynowski, Mountain View, CA (US);
The United States of America as represented by the Secretary of the Army, Washington, DC (US);
Abstract
An isocyanate compound of the general formula R(NCO).sub.n, wherein R is her an aliphatic or an aromatic radical or a combination of both, and n is 1 or a larger integer is prepared by the process comprising dissolving in a high temperature boiling point solvent contained in an agitated, jacketed reactor vessel, an amine of the formula R(NH.sub.2).sub.n, completing a hydrochlorination and precipitation step to form a colloidal suspension of microcrystalline salt particles of amine hydrochloride salt R(NH.sub.2).sub.n.nHCl, introducing oxalyl chloride with agitation and by subsurface injection into the amine hydrochloride salt solution to form an intermediate of amine oxamyl chloride in situ which is thermally decomposed to yield an isocyanate of the general formula R(NCO).sub.n, and separating and purifying the isocyanate by distillation. The unreacted oxalyl chloride and high temperature reaction solvent are recovered by distillation and by absorption from the HCl by-product and are recycled. The by-product HCl is also partially recycled and used for hydrochlorination.