Abstract: An improved method for the manufacture of phosphonoalkyl iminodiacetic acid M2PO3—X—N—(CH2COOM)2 wherein X is a C1-6 linear 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 P4O6.

Abstract: A method for the manufacture of amino alkylene phosphonic acids is disclosed. Pure P4O6 is 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 P4O6 hydrolysis has been completed, from 0 to 40%. The required amine component can be added before, during, or in one preferred execution, after the P4O6 hydrolysis has been completed. Formaldehyde is then added and the reaction mixture containing the P4O6 hydrolysate, 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 sé.

Abstract: A process for the manufacture of dialkyl phosphites is disclosed. In detail, dialkyl phosphites are prepared starting from P4O6, or partially hydrated species thereof cumulatively P—O, by reacting specific molar ratios of alcohol and P—O, containing from 1 to 6 P—O—P bonds in the molecule, in the presence of trialkylphospite (TAP) to thus yield high purity and high yield of dialkyl phosphites. The P—O reactant is preferably represented by liquid P4O6.

Abstract: A method for the manufacture of dialkyl phosphites is disclosed wherein a P—O component containing from 1 to 6 P—O—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.

Abstract: 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 P4O6 with 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.

Abstract: A method for the manufacture of concentrated phosphorous acid starting from pure P4O6 is disclosed. The P4O6 is 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%.

Abstract: An improved method for the manufacture of phosphonoalkyl iminodiacetic acid M2PO3—X—N—(CH2COOM)2 wherein X is a C1-6 linear 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 P4O6.

Abstract: A process for pulp bleaching is disclosed wherein an amino acid phosphonic acid is used together with a bleaching agent, pH regulants and pH buffers for pulp treatment in an aqueous medium. The bleaching agent can be represented by oxidative and reductive bleaching agents. The oxidative bleach treatment is conducted in alkaline medium whereas the reductive treatment is conducted in mildly acid medium.

Abstract: A method for the manufacture of aminopolyalkylene phosphonic acid of a specific general formula is described. In particular, a mixture of specifically defined ranges of reactants to wit: phosphorous acid; an amine; formaldehyde and an aminopolyalkylene phosphonic acid, having the same general formula as the compound to be manufactured, are reacted to thus yield a product of outstanding selectivity and purity with substantially reduced levels of non-desirable by-products.

Abstract: 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.

Abstract: 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 P4O6 with 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.

Abstract: A method for the manufacture of dialkyl phosphites is disclosed wherein a P—O component containing from 1 to 6 P—O—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.

Abstract: A method for the manufacture of dialkyl phosphites by reacting a P—O component containing from 1 to 6 P—O—P bonds in the molecule, with an alcohol and a ketal corresponding to a selected formula, said ketal will not lead to the formation of an enol structure. The level of the ketal is expressed in relation to the level of co-reactants. A preferred ketal is void of any carbon-hydrogen bonds on the ?-carbon atom in the ketal structure.

Abstract: A method for the manufacture of aminoalkylene phosphonic acids broadly is disclosed. In the essence, an amine corresponding to a specific formula is reacted in aqueous medium with phosphorous acid and formaldehyde to thereby yield a medium insoluble reaction product. The insoluble product formed i.e. the aminoalkylene phosphonic acid can be separated, optionally washed, and recovered. This process yields high purity and selectivity reaction products. The excess phosphonic acid can be recycled into the processing sequence.

Abstract: A process for the manufacture of dialkyl phosphites is disclosed. In detail, dialkyl phosphites are prepared starting from P4O6, or partially hydrated species thereof cumulatively P—O, by reacting specific molar ratios of alcohol and P—O, containing from 1 to 6 P—O—P bonds in the molecule, in the presence of trialkylphospite (TAP) to thus yield high purity and high yield of dialkyl phosphites. The P—O reactant is preferably represented by liquid P4O6.

Abstract: An improved method for the manufacture of phosphonoalkyl iminodiacetic acid (PAIDA) is disclosed. The iminodiacetic acid starting material is reacted with a considerable amount, in excess of stoichiometric requirements, of phosphorous acid to thereby yield a reaction medium insoluble reaction product which can be separated from the reaction medium. In a particularly preferred approach, the phosphorous acid is prepared in situ starting from liquid P4O6.

Abstract: 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.

Abstract: A method for the manufacture of amino alkylene phosphonic acids is disclosed. Pure P4O6 is 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 P4O6 hydrolysis has been completed, from 0 to 40%. The required amine component can be added before, during, or in one preferred execution, after the P4O6 hydrolysis has been completed. Formaldehyde is then added and the reaction mixture containing the P4O6 hydrolysate, 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 se.

Abstract: A method for the manufacture of concentrated phosphorous acid starting from pure P4O6 is disclosed. The P4O6 is hydrolysed, 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%.