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:
Aug. 21, 1990
Filed:
May. 11, 1989
Kenneth T Rowbottom, Warrington, GB;
John N Wilkinson, Congleton, GB;
Terence M Conboy, Warrington, GB;
Graham V Hutson, Seascale, GB;
Interox Chemicals Limited, London, GB;
Abstract
Alkyl phosphates, undiluted or dissolved in hydrophobic solvents can be destroyed in situ by reaction with hydrogen peroxide in the presence of certain transition metal catalyst systems. The invention catalyst system comprises a chromium compound, which dissolves in the aqueous phase, typically an alkali metal chromate, which is employed in conjunction with introduction of an alkali, preferably sodium hydroxide, or in the presence of an alkali buffer to keep the pH of the aqueous phase within a window spanning mildly acidic to mildly alkaline pH during the course of progressive introduction of the hydrogen peroxide, which often lasts from 3 to 10 hours, thereby enabling the oxidation of the alkyl phosphate to continue. The reaction is preferably carried out at a temperature of at least 60.degree. C., and particularly at about 65.degree. to 75.degree. C., or at about the boiling point of the aqueous phase. The window becomes somewhat wider as the reaction temperature increases, the term mildly acidic indicating a pH of at least about pH 6 at around 70.degree. C. to at least pH 5 at around 100.degree. C. Preferably, the solution is maintained at a pH of from 6.5 to 7.5.