Basf Aktiengesellschaft

Alois Wiesenberger

Joachim Kranz

Reinhard Sappok

Rudolf Polster

Karl Roth

Fritz Guellich

Grinding crude pigments together with inorganic grinding aids, for example rock salt and dialkyl phthalates, phenoxyethanol, 2-phenylethanol and/or dialkyl benzoates gives soft-textured pigments which produce strong colorings of higher transparency and/or higher cleanliness of hue than prior art pigments.

Preparation of strong and soft-textured surface coating pigments

A process for the preparation of pigmentary forms of phthalocyanine and of insoluble polycyclic compounds, wherein the crude pigment is milled in the presence of one or more acids which have a pK of &lt;4.9 and are non-oxidizing under the milling conditions, until the primary particle size is .ltoreq.0.1 .mu.m, the milled material is then finished in the conventional manner in a solvent in the presence or absence of water, and the pigment is isolated. The pigments give very deep colorations and are very easily dispersible in the media in which they are used.

Preparation of easily dispersible and deeply colored pigmentary forms

Formulations of flavanthrone, pyranthrone, indanthrone, indigo, quinacridone, perylene-3,4,9,10-tetracarboxylic acid dianhydride and perylene-3,4,9,10-tetracarboxylic acid diimide pigments which contain, as additives, one or more compounds of the formula ##STR1## where X is an n-valent radical of a flavanthrone, pyranthrone, indigo, quinacridone, perylene-3,4,9,10-tetracarboxylic acid dianhydride or perylene-3,4,9,10-tetracarboxylic acid diimide pigment, R.sup.1, R.sup.3 and R.sup.4 are hydrogen or chlorine, R.sup.2 is hydrogen, chlorine, carboxyl, bromine, nitro, N-C.sub.1 -C.sub.5 -alkylcarbamyl, N-phenylcarbamyl or benzoylamino and n is 1, 2, 3 or 4. In solutions of surface-coating binders or of surface coatings, the above formulations give very deep colorations, coupled with high gloss and high transparency of the resulting films.

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Lambsheim, Germany

Alois Wiesenberger