Patent GB-424959-A (GB)
Title: Improvements in or relating to washing or laundering processes and compositions therefor
IPC: C02F5/08
Filed: 1933-05-25
Abstract: Water, which has been softened by treatment with the metaphosphate of an alkali-metal or ammonium, capable of rendering calcium and magnesium ionically inert, is used, with or without the addition of soap, for washing fabrics, clothes, hair, hides, leather, the body, dishes, bottles, silverware, windows, walls, painted or varnished surfaces, automobiles, greasy metal parts, &c.  The salt or a solution thereof is preferably added to the water in an amount at least equal to four formula equivalents of the calcium and magnesium present in the water.  Sodium hexa-metaphosphate containing a small amount of pyrophosphate is preferably used.  The pyrophosphate neutralizes the slight acidity of the metaphosphate.  Small quantities of other materials such as caustic soda, sodium carbonate or sesquicarbonate, borax, trisodium phosphate and sodium metasilicate may also be used to neutralize acidity.  And sodium bicarbonate or disodium phosphate may be added as buffering agents to prevent too great acidity or alkalinity.  The metaphosphate may be associated with soap or alkali to form a washing compound.  Water treated as described is stated to be specially useful in laundry work on account of its property of dissolving calcium salts, such as those left in the articles washed from a previous washing operation. Specifications 364,746, 378,345, [both in Group XVIII]; 399,998; 424,677 and 425,001, [both in Group XVIII], are referred to.ALSO:Water, which has been softened by treatment with the meta-phosphate of an alkalimetal or ammonium, capable of rendering calcium and magnesium ionically inert, is used with or without the addition of soap, for washing purposes.  The salt or a solution thereof is preferably added to the water in an amount at least equal to four formula equivalents of the calcium and magnesium present in the water.  Sodium hexa-metaphosphate containing a small amount of pyrophosphate is preferably used. The pyrophosphate neutralizes the slight solidity of the metaphosphate.  Small quantities of other materials such as caustic soda, sodium carbonate or sesquicarbonate, borax, trisodium phosphate and sodium metasilicate may also be used to neutralize acidity.  And sodium bicarbonate or disodium phosphate may be added as buffering agents to prevent too great acidity or alkalinity.  The metaphosphate may be associated with soap or alkali to form a washing compound.  A suitable mixture of metaphosphate and pyrophosphate is obtained by adding a small amount of sodium carbonate to fused monosodium dihydrogen orthophosphate and rapidly cooling the mixture.  Specifications 364,746, [Group XVIII]; 378,345; 399,998, [Group IV]; 424,677, and 425,001 are referred to.ALSO:Water, which has been softened by treatment with the metaphosphate of an alkali-metal or ammonium, capable of rendering calcium and magnesium ionically inert, is used with or without the addition of soap for washing fabrics, clothes, hair, hides, leather, the body, dishes, bottles, silverware, windows, walls, painted or varnished surfaces, automobiles, greasy metal parts, &c.  The salt or a solution thereof is preferably added to the water in an amount at least equal to four formula equivalents of the calcium and magnesium present in the water.  Sodium hexametaphosphate containing a small amount of pyrophosphate is preferably used.  The pyrophosphate neutralizes the slight acidity of the metaphosphate.  Small quantities of other materials such as caustic soda, sodium carbonate or sesquicarbonate, borax, trisodium phosphate and sodium meta-silicate may also be used to neutralize acidity, and sodium bicarbonate or disodium phosphate may be added as buffering agents to prevent too great acidity or alkalinity.  A suitable mixture of metaphosphate and pyrophosphate is obtained by adding a small amount of sodium carbonate to fused monosodium dihydrogen orthophosphate and rapidly cooling the mixture. The metaphosphate may be associated with soap or alkali to form a washing compound.  Water treated as described is stated to be specially useful in laundry work on account of its property of dissolving calcium salts, such as those left in the articles washed from a previous washing operation.  Specifications 364,746, 378,345, 399,998, [Group IV], 424,677, [Group XVIII], and 425,001 are referred to.  The Specification as open to inspection under Sect. 91 describes also the use of metaphosphate for the treatment of boiler feed-water. This subject-matter does not appear in the Specification as accepted.