Method of preparation of improved nigrosine and indulino dyes
AssigneeMontedison S.p.A.
InventorsMario Capaccioni, Laurentino Gentile, Aldo Rusconi
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Abstract
Nigrosine and induline dyes having improved rheological properties are prepared by treating a base of the nigrosine or induline series with between 15 and 30% by weight of phthalic anhydride, at a temperature between 135.degree. and 150.degree. C. The resulting dyes are readily dispersible in plastics and inks and provide finished products having improved flowability.
Claims2
A process for preparing a nigrosine base or an induline base having improved dispersibility, fluidity and flowability in the coloring of plastics and in the preparation of inks, comprising treating a nigrosine base or induline base, at a temperature between 135.degree. and 150.degree. C., with between 15 and 30% by weight of phthalic anhydride, based on the weight of the base.
Dependencies are inferred from the claim text.