GB691475A - New azo colouring matters - Google Patents

Abstract

Metallic salts of 1-phenyl- and 1-tolyl-3-methyl - 4 - carboxyphenylazo - (31 - chloro - 61) 5-pyrazolone are mixed with heated plastic materials for colouring them. The materials may be synthetic resins or cellulose ethers or esters, e.g. polyethylene, polystyrene, urea-formaldehyde condensates, acrylates (such as polymethylmethacrylate) and cellulose acetate. When using thermosetting resins the heating must be controlled to prevent premature hardening. Sodium, potassium, calcium, barium, strontium, magnesium, zinc, lead, manganese and aluminium salts of the dyestuffs may be used. The mixing with the plastic may be carried out in the presence of plasticizers or other liquids, e.g. water, ethanol or acetone. A white pigment such as titanium oxide may be added to give translucent or opaque shades. In examples: (1) polystyrene is melted with the calcium salt of 1-phenyl-3-methyl - 4 - (31 - chloro - 61 - carboxyphenylazo)-5-pyrazolone; (2) as in (1) with the addition of titanium dioxide; (3) a mixture of cellulose acetate, dimethyl phthalate and the colouring matter of (1) is masticated on heated rollers. According to the Provisional Specification the process is also applicable to phenol-formaldehyde resins.ALSO:The invention comprises the metallic salts of 1-phenyl- and 1-tolyl-3-methyl-4-(31-chloro-61 - carboxyphenylazo) - 5 - pyrazolone, such as calcium, strontium, barium, magnesium, zinc, lead, manganese, aluminium, sodium and potassium salts. The last two are made by coupling diazotized 4-chloroanthranilic acid with the appropriate pyrazolone in the presence of caustic soda or potash. The other salts are prepared from these by double decomposition or by coupling in the presence of a soluble salt of the appropriate metal. Examples show the production of the sodium salts of the phenyl and p-tolyl compounds and the calcium and strontium salts of the former. Rosin lakes may be obtained by adding a rosin soap to the coupling mixture before double decomposition with a salt of the laking metal.