Patent GB-581176-A (GB)
Title: Process for improving the fastness of dyeings on cellulose esters matted with titanium dioxide
IPC: D06P1/44
Filed: 1943-03-03
Abstract: The fastness to light of dyeings on cellulose ester materials matted with titanium dioxide, is improved by an after-treatment with melamine.  The process is applicable to cellulose ester artificial silks, matted either by incorporation of the dioxide in the spinning solution, or by treating the fibres with a preparation containing the dioxide.  It is also applicable to artificial silk obtained by the acetylation of viscose or cuprammonium artificial silk which has been matted by incorporating the dioxide in the spinning solution as described in Specifications 353,978 and 379,658.  In examples: (1) cellulose acetate artificial silk, matted by incorporation of titanium dioxide in the spinning solution, and similar material matted by treatment with an aqueous suspension of titanium dioxide containing aluminium triformate, are each dyed by treatment with an aqueous liquor in which 1-amino-4-methylaminoanthraquinone is dispersed with the aid of sulphite cellulose waste liquor and soap, or the sodium salt of the disulphonic acid of m -heptadecyl - N - benzyl - benzimidazole, and the dyed material is then rinsed, treated with a cold aqueous solution of melamine and dried; (2) cellulose acetate artificial silk, matted by incorporation of titanium dioxide in the spinning solution is similarly dyed with 41-nitro-4-di-(b -hydroxyethyl)-amino-3-methyl - 1 : 11-azobenzene and further treated as in (1); (3) similarly, 41-nitro-21-chloro-4-N-ethyl-N-(b -hydroxyethyl) -amino-1 : 11-azobenzene is used to dye cellulose acetate matted with an aqueous suspension of titanium dioxide and aluminium triformate; (4) cellulose acetate, matted as in (2), is dyed with the acid maleic acid ester of 41-nitro-21-methoxy-4-N-ethyl-N-(b -hydroxyethyl) -amino-1 : 11-azobenzene dispersed with Glauber salt and subsequently treated as in (1).  The use of the following dyes also is referred to, symmetrical 1 : 4 - di - (methylamino) - anthra - quinone, the reduction product of the product of the reaction of 1 : 5-dinitro-4 : 8-diaminoanthraquinone with aniline, 1 - phenylamino - 4 - methylaminoanthraquinone, 1 : 4 : 5 : 8 - tetra - aminoanthraquinone, 1 - amino - 4 - hydroxy - anthraquinone, 1-amino-2-methoxy-4-hydroxyanthraquinone, 41 : 61 - dinitro - 21 - methylsul - phone - 4 - N - di - (b -hydroxyethyl)-amino - 1 : 11-azobenzene, 41-nitro-21-methylsulphone-4-N - ethyl - N - b  - methoxyethylamino - 1 : 11 - azo - benzene, 41 - nitro - 4 - N - ethyl - N - (b  - hydroxy - ethyl) - amino - 1 : 11 - azobenzene, 41 - nitro - 21 - chloro - 4 - amino - 1 : 11-azobenzene, 41 - nitro - 4 - amino - 1 : 11 - azobenzene, the azo - dyestuff obtained from diazotised 1-amino-2-nitro-4-methylbenzene and 3-methyl-5-pyrazolone and the acid maleic acid esters of 41-nitro-4-N-ethyl - N - b  - hydroxyethylamino - 1 : 11 - azo - benzene and 41-nitro-21-chloro-4-N-ethyl-N-b -hydroxyethylamino - 1 : 11 - azobenzene.  The process of matting using an aqueous suspension of titanium dioxide containing aluminium triformate, is carried out by treating cellulose acetate artificial silk with a suspension formed by pouring into water, a water paste of titanium dioxide and aluminium triformate, washing and drying.  Specifications 344,117 and 527,834 also are referred to.