Patent GB-449428-A (GB)
Title: Improvements in or relating to the stabilisation of colloidal systems
IPC: C01B25/41
Filed: 1935-06-17
Abstract: The ageing of viscose is retarded by the addition of small quantities, e.g. 0,1--1 per cent of soluble alkali polyphosphates. The polyphosphates may be used in conjunction with other known stabilizing agents or with soluble salts of phosphoric acids containing less water than ortho-phosphoric acid, e.g. pyrophosphates or hypophosphates.  The choice of polyphosphate is dependent on its pH value, which preferably agrees with the pH value of the colloid. The Specification as open to inspection under Sect. 91 describes also the use of polyphosphates with stabilizers consisting of decomposition products of albumins, e.g. lysalbinic acid.  This subject-matter does not appear in the Specification as accepted.ALSO:Colloidal systems, particularly those of vegetable or animal organic products, are stabilized by the addition of small quantities, e.g. 0,1--1 per cent of soluble alkali polyphosphates. By this means, ageing phenomena, e.g. flocculation, thickening of sols, gelatinisation or syneresis of jellies may be prevented or retarded.  The polyphosphates may be prepared by melting alkali pyrophosphates with alkali metaphosphates or directly from their starting substances, e.g. polyphosphates of the formula Na5P3O10 : Na6P4O13 : Na11P9O28 and Na22P10O31 may be employed.  They may be used in conjunction with other known stabilizing agents or with soluble salts of phosphoric acids containing less water than orthophosphoric acid, e.g. pyrophosphates or hypophosphates. The choice of polyphosphate is dependent on its pH value, which preferably agrees with the pH value of the colloid.  They may be applied to stabilize vegetable glues and pastes and other vegetable colloids, e.g. gum arabic solutions and plant juices; to retard the ageing phenomena of viscose; to stabilize sols and gels of silicic acid, silicates or phosphates.  They may also be added to dilute colloidal systems, e.g. latex, milk, plant juices to prevent flocculation &c. on evaporation.  The Specification as open to inspection under Sect. 91 describes also the use of polyphosphates with stabilizers consisting of decomposition products of albumens, e.g. lysalbinic acid, and the preparation of vegetable glues and pastes from aqueous suspensions containing 10--20 per cent of potato or maize starch by heating above 60 DEG  C. or by adding 2--10 per cent of caustic alkali and adding polyphosphates during or after their preparation.  The application of polyphosphates to stabilizing vegetable colloids such as linseed mucilage, salep mucilage or tragacanth: to stabilizing emulsions of oils in aqueous caseinate solutions for use as paints: to the dispersion of lime soaps formed when soap is used in hard water, and to the stabilization of iron phosphate sols used for pharmaceutical purposes is also described. This subject-matter does not appear in the Specification as accepted.ALSO:Colloidal systems, particularly those of vegetable or animal organic products, are stabilized by the addition of small quantities e.g. 0,1-1 per cent. of soluble alkali polyphosphates.  By this means, ageing phenomena e.g. flocculation, thickening of sols, gelatinization or syneresis of jellies may be prevented or retarded. The polyphosphates may be used in conjunction with other known stabilizing agents or with soluble salts of phosphoric acids containing less water than ortho-phosphoric acid, e.g. pyrophosphates or hydrophosphates. The choice of polyphosphate is dependent on its pH value, which preferably agrees with the pH value of the colloid. They may be applied to stabilize vegetable glues and pastes and other vegetable colloids, e.g. gum arabic solutions and plant juices. They may also be added to dilute colloidal systems, e.g. latex, milk, plant juices to prevent flocculation &c. on evaporation.  The Specification as open to inspection under Sect. 91 describes also the use of polyphosphates with stabilizers consisting of decomposition products of albumins, e.g. lysalbinic acid, and the preparation of vegetable glues and pastes from aqueous suspensions containing 10-20 per cent of potato or maize starch by heating above 60 DEG  C. or by adding 2-10 per cent of caustic alkali and adding polyphosphates during or after their preparation.  The application of polyphosphates to stabilizing vegetable colloids such as linseed mucilage, salep mucilage or tragacanth is also described.  This subject-matter does not appear in the Specification as accepted.ALSO:Flocculation of milk, plant juices, &c. on evaporation is prevented by the addition of small quantities, e.g. 0,1-1 per cent of soluble alkali polyphosphates as colloid stabilizers.  The polyphosphates may be used in conjunction with other known stabilizing agents or with soluble salts of phosphoric acids containing less water than ortho-phosphoric acid, e.g. pyrophosphates or hypophosphates.  The choice of polyphosphate is dependent on its pH value, which preferably agrees with the pH value of the colloid.  The Specification as open to inspection under Sect. 91 describes also the use of polyphosphates with stabilizers consisting of decomposition products of albumins, e.g. lysalbinic acid.  This p  subject-matter does not appear in the Specification as accepted.