Abstract: A process is disclosed for the direct preparation of pigmentary 1,4-diketopyrrolo-[3,4-c]pyrroles of the formula (I) wherein each of R1 and R2 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) R1—CN  (II) or of the formula (III) R2—CN  (III) 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.

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.

Abstract: Pyrrolopyrrole derivatives of the formula (I) ##STR1## wherein QA is a quinacridone radical are disclosed. The inventive pyrrolopyrrole derivatives show excellent rheology enhancing properties for pigment dispersions, especially those containing quinacridones, DPPs and their solid solution pigments.

Abstract: The present invention relates to pyrrolopyrrole derivatives of the formula (I) ##STR1## wherein A and B are identical or different aryl radicals, and DPP is a diaryldiketopyrrolopyrrole radical; which diketopyrrolopyrrole derivative is substituted by from 0 to 6 moles of --SO.sub.3 M per mole of the pyrrolopyrrole derivative; wherein M is hydrogen or a metal or ammonium cation. The pyrrolopyrrole derivatives of formula I are useful as rheology-improving agents for pigment dispersions.

Abstract: The present invention relates to pigment and coating compositions that are used to prepare pigmented coatings that exhibit geometric metamerism or metallic flop. The pigment compositions comprise a small particle size pigment and a flop-enhancing agent, which flop-enhancing agent is a copper phthalocyanine, an indanthrone or a carbazole dioxazine compound. A method of enhancing the flop of a pigmented polymeric coating by incorporating one or more flop-enhancing agents into the composition is also disclosed.

Abstract: Binary and ternary pigmentary solid solutions are disclosed. The binary solid solutions are binary solid compounds consisting of 35-45 weight-percent unsubstituted DPP and 55-65 weight-percent dichloro DPP. The ternary solid solutions are guest-host solid solutions wherein the binary solid compound is the host and up to 30 weight-percent of a disubstituted quinacridone pigment is the guest. The binary and ternary solid solutions are useful as pigments for coloring high-molecular-weight organic materials; especially as replacements for perylene pigments in automotive finishes.

Abstract: The present invention relates to novel solid solutions which comprise a quinacridonequinone component, a pyrrolo[3,4-c]pyrrole component and a third component which is a 2-anilinoacridone, a 5,6,7,8-tetrahydro-2-anilinoacridone, 2-phenoxyacridone, a 5,6,7,8-tetrahydro-2-phenoxyacridone or a mixture thereof. The solid solutions are three component solid solutions which consist of the components identified above or are four component solid solutions which additionally contain a quinacridone component. Pigment compositions containing the disclosed solid solutions and a method of pigmenting high molecular weight organic material with the solid solutions are also disclosed.

Abstract: A general method for the direct preparation of pigmentary quinacridone solid solutions is disclosed. The disclosed process comprises oxidizing a mixture of dihydroquinacridones directly to a pigmentary quinacridone solid solution wherein the oxidation is carried out by heating a reaction mixture comprising the dihydroquinacridone mixture, an alkali metal hydroxide, a water miscible organic solvent, water and effective mounts of an oxidizing agent and a particle growth inhibitor. In addition, an analogous process useful for the direct pigmentary synthesis of .alpha.-quinacridone is disclosed. The pigments prepared by the disclosed processes do not require additional particle-size reducing after treatments in order to be useful as pigments.

Abstract: A process for the direct preparation of pigmentary 2,9-dichloroquinacridone, which comprises oxidizing 2,9-dichloro-6,13-dihydroquinacridone directly to pigmentary 2,9-dichloroquinacridone by heating a reaction mixture comprising 2,9-dichloro-6,13-dihydroquinacridone, an alkali metal hydroxide, a water-soluble organic solvent, water and effective amounts of an oxidizing agent and a phthalimidomethylquinacridone particle growth inhibitor. The process yields pigmentary 2,9-dichloroquinacridone directly; without the need for additional particle-size reducing aftertreatments.

Abstract: Aqueous processes for the preparation of a new beta quinacridone modification possessing a magenta color having C.I.E. color space values in masstone of L=33-36, A=34-40 and B=8-15 starting with the crude pigment and comprising several milling and alternative deaggregation and recrystallization steps, the latter being facilitated at elevated temperatures aided by the presence of base and minor amounts of crystal growth auxiliaries, and the beta quinacridone modification having the indicated C.I.E. color space values.