Patent GB-457526-A (GB)
Title: Improvements in the manufacture and production of pigment dyestuffs
IPC: C09B47/04
Filed: 1935-05-29
Abstract: Pigment dyes are prepared by heating a dinitrile of an aromatic-o-dicarboxylic acid, or o-cyanobenzamide, phthalimide, phthalamide or their substitution products, with acid amides other than diamides of aromatic-o-dicarboxylic acids or aromatic - o - cyanocarboxylic acid amides, if desired in the presence of a substance supplying metal.  Suitable acid amides specified are formamide, acetamide, propionamide, higher fatty acid amides, adipic acid amide, toluene sulphamides, and benzamide; they may be employed alone or in admixture with each other or together with other substances such as diluents.  Metals may be present as powders or chips or in the form of oxides, basic carbonates, carbonates, acetates or complex ammonia compounds.  In examples, phthalodinitrile is boiled with formamide in benzophenone; or heated with acetamide and formamide under reflux; or heated with acetamide alone at 220 DEG C.; or boiled with formamide; or heated with formamide in dimethylaniline at 160--180 DEG  C.; or heated with formamide in an autoclave at 195--200 DEG  C. or at 150 DEG  C. in an atmosphere of nitrogen; or heated with formamide, cuprous chloride and pyridine to 150 DEG  C.; or heated with formamide and cobalt carbonate (or nickel carbonate) to 185 DEG  C.; or heated with formamide and ferric oxide to boiling; or heated with formamide and calcium oxide to 180 DEG C.; or heated with formamide and zinc dust in an autoclave in an atmosphere of nitrogen between 140--150 DEG  C.; or fused with o- or p-toluenesulphamide and zinc dust (or cuprous oxide, nickel or cobalt carbonates) to a temperature of 215 DEG  C.; or fused with urea and cuprous chloride to a temperature of 200 DEG  C.; or boiled with formamide and sodium alcoholate (or alkali oxides, carbonates or cyanides); or boiled with formamide and beryllium oxide; or heated with formamide and magnesium oxide at 180--190 DEG  C., or with acetamide or a toluenesulphamide and aluminium chloride or acetate; or heated with formamide and zinc dust (or zinc oxide, acetate or chloride) to about 200 DEG  C.; or boiled with formamide, zinc acetate and nitrobenzene; or heated with formamide and cadmium oxide at 180--190 DEG  C.; or heated with acetamide and ferrous or ferric chloride at 180--190 DEG  C. or with formamide and chromic or anhydrous chromous chloride; or heated with formamide and lead oxide at 190 DEG  C.; or boiled with formamide (or acetamide) and vanadium pentoxide; or heated with formamide and manganese carbonate (or pyrolusite) at 190 DEG  C.; 4-chlorphthalodinitrile is heated with formamide at 190--195 DEG  C.; or with formamide and cuprous chloride in pyridine to 150 DEG  C.; or with formamide and zinc dust at 150 DEG  C.; or with urea and cuprous chloride to 145 DEG  C.; a naphthalene-o-dicarboxylic acid dinitrile is heated with acetamide and formamide under reflux.  In some cases the product is converted into a finely divided form by solution in concentrated sulphuric acid or chlorsulphonic acid and pouring into water, followed if desired, by addition of dispersing agents, or the product may be ground with common salt and this subsequently washed out.