IMPROVENENTS IN OR RELATING TO ORGANIC COMPOUNDS
Liquid compositions of sulphur dyes in leuco (reduced) form, have a total inorganic sulphide contents </= 3 % by weight and a very low content of inorganic salts other than sulphides. They are obtained by reducing a sulphur dye in an alkaline medium to which no sulphide reducing agent has been ad...
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Main Authors | , |
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Format | Patent |
Language | English Korean |
Published |
25.03.1994
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Edition | 5 |
Subjects | |
Online Access | Get full text |
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Summary: | Liquid compositions of sulphur dyes in leuco (reduced) form, have a total inorganic sulphide contents </= 3 % by weight and a very low content of inorganic salts other than sulphides. They are obtained by reducing a sulphur dye in an alkaline medium to which no sulphide reducing agent has been added, preferably employing a reducing sugar (e.g. glucose) as reducing agent. Optionally, prior to reduction, the sulphur dye may be oxidised (e.g. aerated) to eliminate sodium sulphide, treated with sodium sulphite to eliminate elemental sulphur, and washed to eliminate inorganic salts. The reduction may be effected under an inert atmosphere and in the presence of a solubilising agent e.g. diethylene glycol, The liquid compositions have improved stability, and show improved penetration and more moderate substantivity in the dyeing and printing of cellulosics (e.g. cotton) and cellulose-polyester blends. |
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Bibliography: | Application Number: KR19880001508 |