Benckiser-knapsack Gmbh

Hoechst Aktiengesellschaft

Hermann Weber

Klaus Sommer

Wilhelm Spatz

Gerhard Schonmann

Walter Klemm

Frederich Meinhardt

Renate Adrian

Raban Von Schenck

Klaus Somme

A process and apparatus for condensing solid materials such as phosphates which tend to sinter and adhere when heated in a reactor wherein the reactants are introduced into a trough-like reactor provided with at least one set of rotatable agitating paddles. Heat is supplied to the reactor by passing a heating medium, such as a molten salt or a molten metal, through one or more heating jackets on the exterior of the reactor housing. The agitating paddles press the solid material in a thin layer against the wall of the reactor housing, and the material in the layer absorbs heat from the heating medium and sinters to a hard layer. One paddle of each set of paddles is provided with a stripping knife which moves along a path closely adjacent to the exterior wall of the reaction chamber to strip sintered material from the wall of the reactor housing. Heat is also transferred to the interior of the reactor housing by circulating the peeled material through the interior region of the reactor housing.

Process for the condensation of phosphate solids

Disclosed are a composition and method for treating aqueous solutions with N-carboxy alkyl amino alkane polyphosphonic acids which have more than two carbon atoms in their carboxy alkyl group, and their alkali metal salts. The acids and salts are prepared in a good yield by reacting alkali metal salts of amino alkane phosphonic acids in which at least one hydrogen atom of the amino group is unsubstituted, in an alkaline medium with an .alpha.,.beta.-unsaturated carboxylic acid at increased temperature. The free acids are preferably recovered from the reaction solution by a treatment with a cation exchange agent. In place of the .alpha.,.beta.-unsaturated carboxylic acids there can also be used their anhydrides, esters, or nitriles. The resulting polyphosphonic acids have a good complexing or sequestering effect on polyvalent metal ions.

Composition and treating aqueous solutions with N-carboxy alkyl amino

Novel N-carboxy alkyl amino alkane polyphosphonic acids which have more than two carbon atoms in their carboxy alkyl group, and their alkali metal salts are prepared in a good yield by reacting alkali metal salts of amino alkane phosphonic acids in which at least one hydrogen atom of the amino group is unsubstituted, in an alkaline medium with an .alpha., .beta.-unsaturated carboxylic acid at increased temperature. The free acids are preferably recovered from the reaction solution by a treatment with a cation exchange agent. In place of the .alpha., .beta.-unsaturated carboxylic acids there can also be used their anhydrides, esters, or nitriles. The resulting polyphosphonic acids have a good complexing or sequestering effect on polyvalent metal ions.

N-Carboxy alkyl amino alkane polyphosphonic acids

Process and apparatus for the condensation of solids

Novel and highly advantageous N-sulfo alkane amino alkane phosphonic acids and their alkali metal salts are provided. Said phosphonic acids are produced by reacting an alkali metal salt of an amino phosphonic acid with a halo, preferably chloro, or hydroxy alkane sulfonic acid or their alkali metal salts in an alkaline medium, while heating. In place of the halo and especially chloro or hydroxy alkane sulfonic acid reactants, there can also be used compounds which are capable of producing hydroxy alkane sulfonates such as carbylsulfate or aldehydes or, respectively, ethylene oxide with alkali metal bisulfites or metasulfites. The reaction is preferably carried out in a molar proportion of about 1:1 to about 1:2. The novel compounds are excellent complexing or sequestering agents especially with respect to polyvalent metal ions. They are highly resistant against hydrolysis and high temperatures and are of a very high water solubility.

N-Sulfo alkane amino alkane phosphoric acids and their alkali metal

Pure Maddrell salt is produced by heating sodium phosphate to temperatures of 250.degree. to 420.degree. C. The sodium phospate used as starting material is sodium trimetaphosphate or a mixture of sodium trimetaphosphate with Maddrell salt, monosodium orthophosphate or disodium pyrophosphate, the mixture containing Na and P in a molar ratio of 1:1. Prior to heating the starting material, it is admixed with 0.5 to 5 weight% of orthophosphoric acid, polyphosphoric acid, phosphorus pentoxide or at least one salt of a volatile base forming polyphosphoric acid at the temperatures specified. The resulting mixture is calcined over the period necessary to transform the starting material to Maddrell salt.

Production of Maddrell salt

An advantageous process of producing Maddrell salt which is substantially free of water-soluble by-products is described. The resulting substantially water-insoluble Maddrell salt is especially useful as polishing and cleaning agent in toothpaste.

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Hemsbach, Germany

Hermann Weber