Aziende Colori Nazionali Affini Acna S.p.a.

Montedison S.p.a.

Alberto Osti

Francesco De Feo

Franco Gonzati

Filippo M Carlini

Giorgio Bottaccio

Camillo Paffoni

There are described organic-inorganic ternary composite pigments consisting of 70%-90% by weight of an inorganic binary titanium dioxide/aluminum hydrate component and, from 10% to 30% by weight, of a co-precipitated organic component consisting of an organic dye, containing in its structure at least one carboxylic and/or sulphonic acid function, having the formula: ##STR1## wherein R.sub.1 is selected from the group consisting of NO.sub.2 --SO.sub.3 H and --COOH; R.sub.2 is selected from the group consisting of NO.sub.2, --SO.sub.3 H, alkyl and alkoxyl; R.sub.3 is selected from the group consisting of H, halogen and alkyl; R.sub.4 and R.sub.5 are each selected from the group consisting of H, halogen, alkyl and alkoxyl; R.sub.6 is selected from the group consisting of H, halogen and alkoxyl; and wherein the --COOH and/or --SO.sub.3 H group of dye (I) is salified with metal cations. The pigments are obtained by co-precipitation acidifying an aqueous solution and/or dispersion of acid dye (I) in sodium aluminate, in the presence of TiO.sub.2, maintained at 40.degree.-80.degree. C. and at pH=9.5-10.5, by then treating it with any aqueous solution of an alkaline-earth (Ca, Ma, Al, Ba, Sr) salt or of Mn or Zn.

Photostable yellow composite pigments and process for their preparation

7-OXO-7H-dibenzo-[d e,h]-quinolin-2-ol which is useful as an intermediate in the preparation of dyestuffs is prepared by cycloisomerizing the novel compound, N-phenylacetyl phthalimide in an inert solvent and in the presence of a Friedel-Crafts catalyst to form the novel compound O-(3-hydroxy-1-isoquinolinyl)-benzoic acid which is then cyclized by dehydrating condensation to form the 7-oxo-7H-dibenzo-[d e,h]-quinolin-2-ol.

O-(3-hydroxy-1-isoquinolinyl)-benzoic acid

Process for the preparation of 7-oxo-7H-dibenzo-[d e,h]-quinolin-2-ol

Growing community of inventors

Milan, Italy

Alberto Osti