Patent GB-445466-A (GB)
Title: Improvements in or relating to the dyeing or printing of textile materials
IPC: D01C3/02
Filed: 1934-07-10
Abstract: Textile materials are dyed or printed with the addition to the dyebath or printing paste or to a subsequent fixing bath of an alkali metal or ammonium hexametaphosphate.  Improved penetration and fixation of the dyes and improved results in cross dyeing are thereby attained; the hexametaphosphates also have a cleansing action on the fibres and the deposition on the goods of sludge derived from metallic impurities, especially iron and aluminium, present in a dye liquor, is avoided.  The following examples are specified: (A) A dyeing liquor at 100--110 DEG  F. containing Direct deep black E extra, Diazo black BHN, soap, sodium carbonate and sodium hexametaphosphate is circulated through a vessel containing rayon slubbing and steam is introduced to bring the liquor to the boil in 30 minutes, the boiling being then continued for 80 minutes with additions of sodium sulphate at intervals of 20 minutes; the resulting dyeing is a uniform deep black.  (B) Woven mixed goods of wool and silk are dyed in acid baths according to standard practice (1) in an acid bath alone, (2) after mordanting with sodium dichromate, (3) with after-treatment with sodium dichromate, (4) with addition of sodium dichromate to the dyebath, an addition of sodium hexametaphosphate to the dyebath being made in each case; the silk remains a clearer white than when the dyeings are made without such addition.  (C) Worsted slubbing is dyed in a bath containing Diamond blue black RB, Wool violet 4BN, Acid alizarine garnet R, sodium sulphate, acetic acid and sodium hexametaphosphate, the bath being brought to the boil and boiled for 45 minutes, formic acid being then added, boiling continued for a further 30 minutes, sodium dichromate being then added and boiling continued for a further 30 minutes.  (D) Worsted slubbing from oiled tops is dyed in a bath containing Aceko cyanine 3R extra, Wool fast orange GA, Diamond flavine GA, sodium dichromate, sodium sulphate, ammonia, acetic acid and sodium hexametaphosphate, the bath being brought to the boil and boiled for 30 minutes, acetic acid being then added, boiling continued for a further 30 minutes, formic acid being then added and boiling continued for a further 15 minutes with a final addition of more formic acid; the dyeing is free from precipitated sludge.  The invention is applicable for the fixation of dyeings or prints with albumen pigments, after steaming to coagulate the albumen, by adding sodium hexametaphosphate to the soap solution used for washing the dyed or printed fabric.  Specification 424,959 is referred to. Ammonium hexametaphosphate is obtained by heating mono-ammonium di-hydrogen orthophosphate or di-ammonium mono-hydrogen orthophosphate to a dull red heat and rapidly chilling the molten mass.  The Specification as open to inspection under Sect. 91 comprises also the use of the alkali metal or ammonium hexametaphosphates in the degumming of silk by incorporating them in the solution used for softening the cocoons or in the bath through which the filaments are passed before reeling.  This subject-matter does not appear in the Specification as accepted.ALSO:Ammonium hexametaphosphate is obtained by heating mono-ammonium di-hydrogen orthophosphate or di-ammonium mono-hydrogen phosphate to a dull red heat and rapidly chilling the molten mass.