Straitmark Holding Ag

Dequest Ag

Monsanto Technology LLC

Patrick Pierre Notté

Albert Devaux

Samuel Corentin Cogels

David Lemin

Cedric Nicolas Pirard

Samuel Cogels

The present invention is related to a method for the synthesis of ethane-1-hydroxy-1,1-diphosphonic acid or its salt which includes the steps of reacting tetraphosphorus hexaoxide and acetic acid under controlled reaction conditions; hydrolyzing the formed ethane-1-hydroxy-1,1-diphosphonic acid condensates to form ethane-1-hydroxy-1,1-diphosphonic acid; further processing the ethane-1-hydroxy-1,1-diphosphonic acid solution. The process according to the method of the present invention is highly controllable and further is characterized by a high selectivity.

Method for the synthesis of ethane-1-hydroxy-1,1-diphosphonic acid

An improved method for the manufacture of phosphonoalkyl iminodiacetic acid MPO&#x2014;X&#x2014;N&#x2014;(CHCOOM)wherein X is a Clinear or branched alkyl group; and M is selected from hydrogen, alkali, earth-alkali, ammonium and protonated amine is disclosed. The iminodiacetic acid starting material is reacted with a substantially stoichiometric amount of phosphorous acid, in the presence of a large excess of phosphoric acid to thereby yield a reaction medium insoluble reaction product (PAI-DA) which can be separated from the reaction medium. In a particularly preferred approach, the phosphorous acid is prepared in situ starting from liquid PO.

Method for the manufacture of phosphonoalkyl iminodiacetic acid

A method for the manufacture of amino alkylene phosphonic acids is disclosed. Pure POis hydrolyzed in the presence of a homogeneous Broensted acid catalyst whereby the pH of the reaction medium is maintained below 5 and the free water content of said reaction medium is, after the POhydrolysis has been completed, from 0 to 40%. The required amine component can be added before, during, or in one preferred execution, after the POhydrolysis has been completed. Formaldehyde is then added and the reaction mixture containing the POhydrolysate, the amine and the formaldehyde is reacted in presence of a Broensted acid catalyst selected from homogeneous and heterogeneous species. The amino alkylene phosphonic acid reaction product can then be recovered in a manner known per s&#xe9;.

Method for the manufacture of aminoalkylene phosphonic acid

A process for the manufacture of dialkyl phosphites is disclosed. In detail, dialkyl phosphites are prepared starting from PO, or partially hydrated species thereof cumulatively P&#x2014;O, by reacting specific molar ratios of alcohol and P&#x2014;O, containing from 1 to 6 P&#x2014;O&#x2014;P bonds in the molecule, in the presence of trialkylphospite (TAP) to thus yield high purity and high yield of dialkyl phosphites. The P&#x2014;O reactant is preferably represented by liquid PO.

Process for the manufacture of dialkylphosphites

A method for the manufacture of dialkyl phosphites is disclosed wherein a P&#x2014;O component containing from 1 to 6 P&#x2014;O&#x2014;P bonds in the molecule is reacted with an alcohol and a carboxylic acid ester having from 1 to 6 carbon atoms in the alkyl group and from 5 to 20 carbon atoms in the esterifying alkyl group of the ester. The dialkyl phosphites are formed under simultaneous removal by distillation of the carboxylic acid formed.

Method for the manufacture of dialkylphosphites

The technology of this invention concerns a method for the manufacture of hydroxy diphosphonic acids containing an amino moiety. The method specifically involves reacting a liquid POwith an aminocarboxylic acid in the presence of a sulfonic acid. The aminocarboxylic acid is selected from 3 structurally different compounds. The amino hydroxy diphosphonic acids can be synthesized with high selectivity and purity and the unreacted starting raw materials can easily and conveniently be recirculated.

Method for the manufacture of aminohydroxy diphosphonic acids

A method for the manufacture of concentrated phosphorous acid starting from pure POis disclosed. The POis hydrolyzed, preferably under stirring in water in the presence of a homogeneous Broensted acid catalyst while maintaining in the hydrolysis/reaction medium a pH below 5 whereby the free water level, at the completion of the hydrolysis, is in the range from 0 to 40%.

Method for the manufacture of concentrated phosphorus acid

A method of secondary oil recovery is disclosed wherein from 0.1 to 100 000 ppm of a medium soluble aminoalkylene phosphonic acid amine salt are used wherein both the aminoalkylene phosphonic acid moiety and the amine moiety are selected from a specifically defined class of compounds. The substantially medium soluble aminoalkylene amine phosphonates exhibit a significantly improved compatibility with the recovery medium and thus can propagate fairly freely into the medium and consequently cover a largely extended rock surface before being subject to precipitation in the form of a medium insoluble scale inhibitor. The amine compound is represented by combinations of structurally different compounds.

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Wavre, Belgium

Patrick Pierre Notté