Abstract: An improved process for the preparation of optionally substituted 2-anilinoacridones from optionally substituted 2,5-dianilinoterephthalic acids, comprises:(a) cyclizing 2,5-dianilinoterephthalic acid to give an intermediate product mixture which contains a major portion of a 2-anilino-3-carboxyacridone and a minor portion of a quinacridone;(b) combining said intermediate product mixture with a solvent which dissolves the 2-anilino-3-carboxyacridone at elevated temperatures but does not dissolve the quinacridone;(c) decarboxylating the 2-anilino-3-carboxyacridone in the mixture from step (b) at elevated temperatures to yield a product slurry comprising a solid quinacridone and a 2-anilinoacridone dissolved in the solvent;(d) separating the solid quinacridone, the catalyst, and other solid impurities from the solvent, whereby a solution containing the dissolved 2-anilinoacridone is obtained; and(e) subsequently separating the dissolved 2-anilinoacridone from the solvent.

Abstract: A process for preparing transparent, pigmentary quinacridone compounds and solid solutions thereof comprises combining a premilled, sub-pigmentary powder containing at least one unsubstituted or substituted quinacridone or a derivative thereof with a sufficient amount of moderately concentrated sulfuric acid to form a slurry, then agitating this slurry in the presence of an organic liquid which is immiscible or only partially miscible with the slurry and which is effective in deagreggating and improving the crystallinity of the pigment, for an effective length of time to convert the sub-pigmentary unsubstituted or substituted quinacridone or solid solution thereof to a transparent, pigmentary form.

Abstract: Fluorescent yellow pigments comprising 1,2,3,4-tetrachloro-11H-isoindolo-?2,1-a!-benzimidazol-11-one and various derivatives thereof; the use of said pigments in a variety of substrates such as alkyds, enamels, inks and the like; a process for the preparation thereof involving the condensation of the appropriate o-phenylenediamine and tetrachlorophthalic anhydride; and the aforementioned novel derivatives of said compound.

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: A violet quinacridone pigment composition comprising a pigmentary 2,9-dichloroquinacridone pigment having a specific surface area below 75 m.sup.2 /g and a sulfonated indanthrone or copper phthalocyanine. The compositions have excellent fastness properties when used for pigmenting engineering plastics.

Abstract: A process for preparing quinacridone pigments comprising oxidizing 6,13-dihydroquinacridone or derivatives thereof at elevated temperatures in the presence of a base, dimethyl sulfoxide medium and a quinone catalyst, drowning the resulting pigment solution to precipitate the quinacridone pigment and isolating the desired quinacridone product.

Abstract: A process for preparing a modified beta quinacridone polytype having identified color space values which comprises the steps of dry pre-milling beta phase quinacridone, deaggregating the pre-milled product in an alcohol-base medium and ripening the deaggregated product in the presence of an oxidizing agent.

Abstract: A new gamma quinacridone polytype having a yellowish-red color and a distinct X-ray diffraction pattern, said new form being prepared directly in high yield in pigmentary form by oxidation of 6,13-dihydroquinacridone in a basic dimethylsulfoxide medium.

Abstract: A process for converting crude pigments into pigmentary form wherein the crude pigment is premilled, then contacted with a polar solvent at temperatures below 50.degree. C., with or without the presence of particle growth inhibitors, and finally isolated.

Abstract: The use of 2,9-dichloroquinacridone having a surface area below 30 m.sup.2 /g as a pigment in engineering plastics and coating wherein said pigment exhibits outstanding heat stability and a unique red color in the resulting pigmented system.

Abstract: 2,9-Dichloroquinacridone in platelet form having a length of 1-45 .mu.m, a width of 0.1-20 .mu.m and a thickness of 0.05-5 .mu.m; a process for the preparation thereof comprising conversion of the crude material in a polar solvent in the presence of a long chain thiol compound and a base; and the pigmentary use of said platelets.

Abstract: 5,15-Diaza-5b, 15b-dihydrotetrabenzo[a,g,j,p] perylene-6,16-dione, a process for the preparation thereof and its suitability for use as a pigment for coloring a wide variety of organic materials.

Abstract: Pearlescent coating compositions comprising a resin binder system, coated mica particles and a manganese salt of an azo pigment, these coating compositions being of particular value in two coat automotive paint systems wherein the pearlescent composition is applied as the base coat which is covered with a clear top coat to provide paint systems with intense color, high pearlescence and excellent durability.

Abstract: Process for the preparation of opaque 1,4-diketopyrrolo-[3,4-c]pyrroles of the formula ##STR1## wherein one of R.sub.1 and R.sub.2 is hydrogen, halogen or C.sub.1 -C.sub.4 -alkyl and other is hydrogen, which process essentially consists of milling the pigment in an alcohol and in the presence of a base at a temperature below 50.degree. C., the resulting product being a highly crystalline readily dispersable diketopyrrolopyrrole pigment having outstanding color strength, purity of shade and saturation.

Abstract: A process for preparing opaque pigmentary quinacridone derivatives which comprises milling the starting quinacridone materials at ambient or near ambient temperatures in the presence of an alcohol and a base.

Abstract: A process for preparing pigmentary solid solutions of at least one quinacridone derivative and the parent quinacridone compound which comprises milling the starting quinacridone materials at ambient or near ambient temperatures in the presence of an alcohol and a base.