The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 02, 2000
Filed:
May. 13, 1999
Shivakumar B Hendi, Newark, DE (US);
Ciba Specialty Chemicals Corporation, Tarrytown, NY (US);
Abstract
A process is disclosed for the direct preparation of pigmentary 1,4-diketopyrrolo-[3,4-c]pyrroles of the formula (I) ##STR1## wherein each of R.sub.1 and R.sub.2 independently of the other is an isocyclic or heterocyclic aromatic radical, which process comprises heating an appropriate molar ratio of a disuccinate with a nitrile of the formula (II) ##STR2## or of the formula (III) ##STR3## or with mixtures of said nitrites, in an organic solvent and in the presence of a strong base and an effective amount of a selected particle growth inhibitor of formula (IV)-(X), and then obtaining the compound of formula (I) from the reaction product by protolysis. The process yields pigmentary 1,4-diketopyrrolo-[3,4-c]pyrroles directly, i.e., without the need for additional particle-size reducing aftertreatments. Also disclosed is a composition comprising a pigmentary 1,4-diketopyrrolo-[3,4-c]pyrrole and the particle growth inhibitor. These pigment compositions are useful for pigmenting high molecular weight organic materials.