Patent GB-835877-A (GB)
Title: Method of producing perpolyphosphates or salt mixtures containing the same
IPC: C01B15/00
Filed: 1956-03-02
Abstract: Inorganic perpolyphosphates are obtained by reaction of hydrogen peroxide and/or an adduct liberating hydrogen peroxide with a polyphosphate in the course of a spray drying process at 100 DEG  to 600 DEG  C.  Adducts specified are those with alkali metal borate, pyrophosphate, polyphosphate and carbonate or with urea. The reactants may first be mixed and then spray dried, or they may be introduced separately into the spray drier; in the latter case, the hydrogen peroxide or adduct thereof may be brought into contact in the spray drier with the polyphosphate after the latter has been converted therein to a solid.  There may also be present with the polyphosphate other salts such as sodium sulphate and other sodium phosphates, and at least one of the reactants, preferably the peroxide reactant may contain stabilizers, e.g. phosphoric acid, alkali metal pyrophosphate and silicate, magnesium metasilicate and polysilicate and their formation components, alkali metal nitrilotriacetates or ethylenediaminotetraacetate, soluble albuminous compounds or their decomposition products, e.g. alkali metal salts of protalbinic or lysalbinic acid.  Products in the form of aggregates of hollow spheres may be produced by adjusting the spraying conditions.  In examples (1) sodium tripolyphosphate, tetrasodium pyrophosphate, sodium sulphate, magnesium silicate and sodium ethylenediaminotetraacetate is made into a paste with hydrogen peroxide solution and spray dried at 300 DEG  C.; (2) sodium tripolyphosphate, sodium carbonate, sodium perborate (stabilized with magnesium silicate) is mixed into a paste with hydrogen peroxide (stabilized with sodium ethylenediaminotetraacetate) and spray dried as in (1).ALSO:Bleaching and cleansing agents comprise inorganic perpolyphosphates obtained by reaction of hydrogen peroxide and/or an adduct liberating hydrogen peroxide with a polyphosphate in the course of a spray-drying process at 100 DEG  to 600 DEG  C.  Products of a similar kind which may contain or be free from per salt, and organic detergents, may also be present in the composition, preferably in the form of spray-dried hollow spheres.  Adducts specified are those with alkali metal borate, pyrophosphate, polyphosphate and carbonate or with urea.  There may also be present with the polyphosphate other salts such as sodium sulphate and other sodium phosphates, and at least one of the reactants, preferably the peroxide reactant, may contain stabilizers, e.g. phosphoric acid, alkali-metal pyrophosphate or silicate, magnesium metasilicate or polysilicate or their formation components, alkali metal nitrilotriacetates or ethylenediaminotetra-acetates, or soluble albuminous compounds or their decomposition products, e.g. alkali-metal salts of protalbinic or lysalbinic acid.ALSO:Disinfectants may comprise inorganic perpolyphosphates obtained by reaction of hydrogen peroxide and/or an adduct liberating hydrogen peroxide with a polyphosphate in the course of a spray drying process at 100 DEG  to 600 DEG  C.  Products of a similar kind which may contain or be free from per salt, and organic detergents may also be present in the composition, preferably in the form of spray dried hollow spheres.  Adducts specified are those with alkali metal borate, pyrophosphate, polyphosphate and carbonate or with urea.  There may also be present with the polyphosphate other salts such as sodium sulphate and other sodium phosphates, and at least one of the reactants, preferably the peroxide reactant may contain stabilizers, e.g. phosphoric acid, alkali metal pyrophosphate and silicate, magnesium metasilicate or polysilicate or their formation components, alkali metal nitrilotriacetates or ethylenediaminotetra-acetate, soluble albuminous compounds or their decomposition products, e.g. alkali metal salts of protalbinic or lysalbinic acid.  In examples: (1) sodium tripolyphosphate, tetrasodium pyrophosphate, sodium sulphate, magnesium silicate and sodium ethylenediaminotetra-acetate is made into a paste with hydrogen peroxide solution and spray dried at 300 DEG  C.  (2) Sodium tripolyphosphate, sodium carbonate, sodium per borate (stabilized with magnesium silicate) is mixed into a paste with hydrogen peroxide (stabilized with sodium ethylenediaminotetra-acetate) and spray dried as in (1).