Patent GB-639998-A (GB)
Title: Preparations containing alkali sulphides
Filed: 1947-02-18
Abstract: Stable preparations of alkali sulphides are made by bringing together an alkali sulphide and a water soluble or alkali-soluble cellulose ether in presence of water and under swelling conditions and removing the water by drying.  If products such as a sulphur dye, which are capable of neutralizing the reducing power of alkali sulphide, are present, a substantial excess of alkali sulphide is employed.  A sulphur dye or its leuco compound may be incorporated dry in the dry mixture, or its leuco compound may be incorporated in the moist state, with subsequent drying.  Also, the dye may be vatted in presence of excess sulphide and water-soluble or alkali-soluble cellulose ether under swelling conditions and drying.  Examples describe the vatting of Pyrogene Brown G with sodium sulphide solution and the sodium salt of cellulose glycollic acid ether or methyl cellulose. Specifications 418,746 and 636,399, [Group IV (c)], are referred to.ALSO:Stable preparations of alkali sulphides are made by bringing together an alkali sulphide and a starch or a water-soluble or alkali-soluble cellulose ether in presence of water and under swelling conditions and removing the water by drying.  If products such as a sulphur dye, which are capable of neutralizing the reducing power of alkali sulphide, are present, a substantial excess of alkali sulphide is employed.  A sulphur dye or its leuco compound may be incorporated dry in the dry mixture, or its leuco compound may be incorporated in the moist state, with subsequent drying.  Also, the dye may be vatted in presence of excess sulphide and starch or a water-soluble or alkali-soluble cellulose ether under swelling conditions and drying.  Starches specified are wheat, maize, potato, or rice starch.  The sulphur dyes may be obtained by sulphurizing such bodies as anthracenes, pyrene, amines of the benzene or naphthalene series, imidazoles, nitrophenols, indophenols, in an alkaline, neutral, or acid melt. Examples describe (1) the mixing of sodium sulphide, wheat starch, and water, evaporation of the mixture, and mixing of the dried product with Pyrogene Green 3G; (2) the vatting with sodium sulphide solution and starch, followed by drying under reduced pressure, of Pyrogene Yellow O, Pyrogene Deep Black D and Pyrogene Green 3G; (3) the vatting of Pyrogene Brown G with sodium sulphide solution and the sodium salt of cellulose glycollic acid ether or methyl cellulose.  A further example describes the dyeing of cotton with the product of (1).  Specifications 418,746 ALSO:Stable preparations of alkali sulphides are made by bringing together an alkali sulphide and a starch or a water soluble or alkali-soluble cellulose ether in presence of water and under swelling conditions and removing the water by drying.  If products such as a sulphur dye, which are capable of neutralising the reducing power of alkali sulphide, are present, a substantial excess of alkali sulphide is employed.  A sulphur dye or its leuco compound may be incorporated dry in the dry mixture, or its leuco compound may be incorporated in the moist state, with subsequent drying.  Also, the dye may be vatted in presence of excess sulphide and starch or a water-soluble or alkali-soluble cellulose ether under swelling conditions and drying.  Starches specified are wheat, maize, potato, or rice starch.  Examples describe (1) the mixing of sodium sulphide, wheat starch, and water, evaporation of the mixture, and mixing of the dried product with Pyrogene Green 3G, (2) the vatting with sodium sulphide solution and starch, followed by drying under reduced pressure, of Pyrogene Yellow O, Pyrogene Deep Black D and Pyrogene Green 3G. Specifications 418,746, [Group IV], and 636,399, [Group IV (c)], are referred to.