Patent GB-871624-A (GB)
Title: Azopyrimidine compounds and process of coloring fabricated polyacrylonitriles therewith
IPC: C09B27/00
Filed: 1957-10-28
Abstract: Polyacrylonitrile, containing at least 85% by weight of acrylonitrile, is coloured with a 2, 4, 6-trisubstituted-5-aryl- or heterocyclic-azo-pyrimidine in which the 2-substituent is an amino group, which may be alkylated, and at least one of the 4- or 6-substituents is an amino group, the other being when not an amino group, hydroxyl, the aryl or heterocyclic group being free from ionogenic acidic groups. Preferred polyacrylonitriles are those containing no basic comonomers e.g. methylvinylpyridine and vinylpyridine.  Specified as comonomers which may be present are methyl acrylate and vinyl acetate and chloride.  The dyes may be used as a paste or as a fine powder.  Dyeing is effected, at the boil, from an acidic aqueous dye bath and, if necessary, in the presence of dispersing agents.  Printing processes may also be adopted.  The polyacrylonitrile may be in such forms as fibres, granules, powders or films.  Indicated arylamines from which the dyes may be derived are: aniline, chloro-, cyano- and alkoxy-anilines and their benzamido- and p-sulphonyl-derivatives, a - and b -naphthylamines, biphenylamines, aminodiphenylamines and aminoazo compounds. Specified pyrimidines are: 2, 4-diamino-6-hydroxy-, 2, 4, 6-triamino-, 2-amino-4b -hydroxyethylamino-6-hydroxy-, 2-amino- 4-ethoxycarbonylmethylamino- 6-hydroxy-, 2, 4-diamino- 6-dimethyl- and -diethyl-amino-, 4, 6-diamino-2-diethyl- and diallyl-amino-, 2-amino-4, 6-di(monomethylamino)- and 4-amino-2-diallylamino-6-hydroxypyrimidine and its 2-dialkylamino derivatives.  Red, blue, yellow and brown shades are obtained. Additional diazo components used in the examples, which illustrate the colouring of fibres, are p-toluidine and 3- and 4-aminopyridine.ALSO:The invention comprises the following dyes:-2, 4-diamino- 5-(2, 5-dimethoxy-, p-methyl-sulphonyl-, 4- p-anisidino-, 4-benzamido-2, 5-diethoxy-, 4-diphenyl-, 4-phenylamino-, 4-phenylazo-, 4-sulphonamido- and 4-cyan-2, 5-dimethoxy-phenylazo)-6-hydroxypyrimidines, 2, 4-diamino- 5-(1-naphthyl- and -anthraquinonyl- and 8-quinolyl-azo)- 6-hydroxypyrimidines, 2, 4-diamino- 5-(2, 4-diamino- 6-hydroxy-5-pyrimidylazo)- and -(4-styrylphenylazo)- 6-hydroxypyrimidines, 2-dimethylamino- 4-amino- 5-p-tolyl-, (4-p-anisylphenyl)- and p-chlorophenyl-azo- 6-hydroxypyrimidines and 2-diallylamino- 4-amino- 5-(p-tolylazo)- and 2-di-(2-butenyl)-amino- 4-amino- 5-(2, 5-dimethoxyphenylazo)-6-hydroxypyrimidines and the colouring of polyacrylonitrile, comprising at least 85% by weight acrylonitrile, with 2, 4, 6-trisubstituted- 5-aryl- or -heterocyclic-azopyrimidines in which the 2-substituent is an amino, or alkylated amino, group and at least one of the 4- or 6-substituents is an amino group, the other being, when not an amino group, hydroxyl, the aryl or heterocyclic group being free from ionogenic acidic groups.  The dyes are made by conventional processes and preferably by coupling a diazotized arylamine with the pyrimidine component.  Indicated arylamines are:-aniline, chloro-, cyano- and alkoxy-anilines and their benzamido- and p-sulphonyl derivatives, a - and b -naphthylamines, biphenyl-amines, aminodiphenylamines and aminnoazo compounds. Specified pyrimidines are:-2, 4-diamino- 6-hydroxy-, 2, 4, 6-triamino-, 2-amino- 4-b -hydroxyethylamino- 6-hydroxy-, 2-amino- 4-ethoxy-carbonylmethylamino- 6-hydroxy-, 2, 4-diamino- 6-dimethyl- and -diethylamino-, 4, 6-diamino- 2-diethyl- and -diallylamino-, 2-amino-4, 6-di-(monomethylamino)- and 4-amino- 2-diallylamino- 6-hydroxypyrimidine and its 2-dialkylamino derivatives.  The polyacrylonitrile may be in such forms as fibres, granules, powders and films.  Preferably basic comonomers, e.g. methylvinylpyridine and vinylpyridine, are absent.  Specified comonomers are methyl acrylate and vinyl acetate and chloride.  The dyes may be used as a paste or as a fine powder.  Dyeing is effected at the boil from an acidic aqueous dye bath and, if necessary, in the presence of conventional dispersion agents.  In examples, which illustrate the preparation of the dyes and their use in colouring polyacrylonitrile fibres, the components used are chosen from those indicated above, with the addition of p-toluidine and 3- and 4-aminopyridine as diazo components.  Red, blue, yellow and brown shades are obtained.