Ciba-geigy Corporation

Ciba Specialty Chemicals Corporation

David McGregor

James M McCrae

Ian R Wheeler

George H Robertson

Paul Kerwin

John B Blackburn

Donald J Morrison

The present invention provides the use of a resinated pigment in which from 10 to 100% of the resinated proportion of the product is a resin ester, as colourant in a lithographic printing ink.

Pigment compositions

A process for the production of a pigment composition comprising precipitating a pigment coupling component from alkaline solution by adding to it an acid, in the presence of a pre-formed, water-soluble azo dyestuff; and subsequently coupling the precipitated coupling component, containing the azo dyestuff, with a pigment diazo or tetrazo component, ensuring that at no time is any substantial amount of uncoupled diazo or tetrazo component present, to form a pigment composition containing the water-soluble azo dyestuff.

Process for the production of pigments in the presence of an azo dyestuff

A process for conditioning pigments which comprises grinding a crude copper phthalocyanine pigment and a crystallizing solvent in the absence of inorganic salt but in the presence of one or more sulphonated phthalocyanine amine derivative having the general formula ##STR1## wherein Pc is a phthalocyanine, R.sup.1, R.sup.3 and R.sup.4 are hydrogen or a hydrocarbon residue, R.sup.2 is a hydrocarbon residue, p is 0 to 3, q is 1 to 4, and the sum of p and q is 1 to 4, the resulting pigment composition is freely dischargeable from the mill in high yield and is, moreover largely in the .beta.-form.

Process for conditioning phthalocyanine pigment

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Glasgow, United Kingdom

David McGregor