GB966487A - Coloured articles of polyoxymethylene and copolyoxymethylenes - Google Patents

Abstract

Coloured shaped articles comprising oxymethylene polymers are prepared by incorporating therein a basic or anionic exchange substance and dyeing with an acidic dyestuff which, in the free acid form is less than 10% ionised in normal aqueous solution at 20 DEG C. Specified polymers are polyoxymethylenes and copolyoxymethylenes containing 1 to 10% (mol) of other oxyalkylene units. Suitable basic or anionic exchange substances include oxides, hydroxides and salts of alkali metals, alkaline earth metals, magnesium, aluminium, titanium, zirconium, rare earth metals, zinc, lead and tin, e.g. zinc stearate, magnesium oxide, potassium carbonate, calcium hydroxide, hydroxyapatite, zinc naphthenate, manganese stearate, aluminium acetylacetonate, cobalt stearate, thoria, zirconia, calcium stearate, magnesium stearate and aluminium nonanoate. In examples these materials are added to 99/1 (mol) formaldehyde-ethylene oxide copolymers and the compositions melt spun to form filaments which are then dyed.ALSO:Shaped articles, such as fibres, filaments and yarns, of compositions comprising polyoxymethylenes or copolyoxymethylenes, e.g. containing 1 to 10 mol per cent of other oxyalkylene units, and basic or anionic exchange substances, are dyed with acidic dyestuffs which in the free acid form are less than 10% ionised in normal aqueous solution at 20 DEG C. Suitable dyes are those containing sulphonamide, phenolic and carboxylic acid groups. In examples a three filament yarn melt spun from a mixture of a 99/1 formaldehyde ethylene oxide copolymer and zinc stearate is dyed with 1, 2, 3-dihydroxyintroanthraquinone, 1, 2, 5, 8-tetrahydroxyanthraquinone, 1, 2, 3-trihydroxyanthraquinone, the condensate of diazotised para-introaniline and salicylic acid, and dyes of formulae <FORM:0966487/D1-D2/1> and <FORM:0966487/D1-D2/2> and filaments melt spun from mixtures of 99/1 formaldehyde ethylene oxide copolymers and magnesium oxide, potassium carbonate, calcium hydroxide, hydroxy apatite, zinc stearate, zinc naphthenate, manganese stearate, aluminium acetylacetonate, cobalt stearate, thoria, zirconia, calcium stearate, magnesium stearate and aluminium nonanoate are dyed with 1, 2-dihydroxyanthraquinone, 1, 2, 3-dihydroxynitroanthraquinone, and the condensation products of diazotised p-nitroaniline with salicylic acid, diazotised o-hydroxyaniline with 2, 4-dihydroxynaphthalene, diazotised p-methylaniline with 8-hydroxyquinoline, diazotised 2, 4-dichloroaniline with salicylaldoxine, and diazotised p-nitroaniline with 4-hydroxy 2-acetylaminobenzthiazole.