Patent GB-853778-A (GB)
Title: Improvements in or relating to lakes of monoazo dyestuffs
IPC: C09B29/32
Filed: 1958-05-13
Abstract: Plastic compositions, lacquers, and filamentforming solutions having a basis of cellulose esters, polyvinyl chloride, or other plastic substance, are pigmented by means of lakes obtained from monoazo dyes of the formula:  <FORM:0853778/IV(a)/1> wherein A1 and A2 are mono- or di-nuclear aromatic radicals, A2 being free from watersolubilizing groups, and R is an alkyl or aryl radical.  A1 and A2 may contain further nuclear substituents such as bromine, chlorine, methyl, ethyl, methoxy, ethoxy, acetylamino, and benzoylamino groups. Metal compounds which may be reacted with the azo dyes to form the lakes are salts of Ca, Sr, Ba, Mg, Mn, Zn, Cd, Pb, Al, Cu, Co, Fe, and Ni. In an example, the monoazo dye 1 - amino - 5 - methyl - 4 - chlorobenzene - 2 - sulphonic acid ---> 1-acetoacetylamino-2-methoxybenzene is formed into a lake by treatment with calcium chloride; the lake is wetted with dioctyl phthalate and incorporated in a polyvinyl chloride composition containing dioctyl phthalate as plasticizer; films of a greenish yellow colour, fast to light, are obtained.  In another example, a calcium lake of the dye 1-amino-5-methyl - 4 - chlorobenzene - 2 - sulphonic acid ---> 1 - acetoacetylamino - 2, 5 - dimethoxy -4 - chlorobenzene is ground with a nitrocellulose lacquer until the pigment particles are not larger than 1m .  A barium lake of the previously mentioned monoazo dye is used for the mass pigmentation of cellulose triacetate or secondary cellulose acetate.  Filaments obtained from the pigmented composition are of a yellow shade, fast to light, chlorine, peroxide, and other chemicals.ALSO:The invention comprises colour lakes obtained from monoazo dyestuffs of the formula:  <FORM:0853778/IV (c)/1> wherein A1 and A2 are mono- or dinuclear aromatic radicals, A2 being free from watersolubilizing groups, and R is an alkyl or aryl radical.  The invention also comprises a process for the production of lakes which consists in treating monazo dyestuffs of the acylacetic acid amide series, which contain one sulphonic acid group in the diazo component but no other watersolubilizing groups except the enolizable -CO-group of the acylacetylamino radical, with watersoluble compounds of divalent or multivalent metals.  For the production of the monoazo dyes there may be used as coupling components acylacetylaminobenzenes or -naphthalenes.  The benzene nuclei adjacent the -NH- groups may be free of other substituents or may contain methyl, ethyl, methoxy, ethoxy, or other alkyl or alkoxy groups, or halogen atoms such as bromine or chlorine, or acetylamino or benzoylamino groups. Specified coupling components include 1- acetoacetylamino -2.5- dimethoxy -4-chlorobenzene, 1- acetoacetylamino -2- methoxybenzene, 1- and 2- acetoacetylaminonaphthalene, benzoylacetylaminobenzene, and 1-benzoylacetylamino -2-, -3-, or -4- methyl, -2-, -3- or -4- methoxy, -2-, -3-, or -4- chlorobenzene.  Specified diazo components include those obtained from 1- aminobenzene -2-, -3-, or -4- sulphonic acid, 1- amino -4 or 5- methyl- or -4- methoxy or -4- chlorobenzene -2- sulphonic acid, 1- amino- 2.5 or 4.5- dichlorobenzene -2 or 4- sulphonic acid, 1- aminonaphthalene -2, 4, or 8- sulphonic acid, and 2- aminonaphthalene -1, 5, 6, 7 or 8- sulphonic acid.  Pyridine may be present during the coupling reaction.  If desired, the coupling reaction giving the monoazo dye and the reaction with metal salt to form a lake may be effected simultaneously, the coupling being conducted in a medium rendered alkaline with a hydroxide of the metal used for laking, if desired with the addition of an alkali metal hydroxide.  Alternatively, the diazo solution or suspension may be mixed with a solution of the metal salt and the mixture then run into a solution of the coupling agent.  Compounds of alkaline-earth metals, aluminium, manganese, magnesium, iron, cobalt, nickel, copper, zinc, cadmium and lead, may be used for forming the lakes.  The lakes may be dried and ground, grinding being preferably carried out in presence of a dispersing agent, binder, or plasticizer.  Soap, alkylarylsulphonates, sulphonated fatty alcohols, rosin soap, fat or oil emulsions, or fillers may be incorporated in the lakes. The lakes may be used for colouring polyvinyl chloride and other plastics and colouring lacquers; for mass pigmentation of manufactured fibres; for dyeing paper furnishes in the beater, and for printing textiles, leather and paper.