Abstract: A process for converting perylene-3,4:9,10-tetracarboximides of the general formula I in which R1 and R2 are each unbranched, branched or cyclic C1-C8-alkyl to a form suitable for use as fluorescent dyes, which comprises a) dissolving or suspending the perylene-3,4:9,10-tetracarboximides whose molecules have a molecular volume of ?230 ?3 in an organic or inorganic solvent at from 0 to 250° C.

Abstract: A process for preparing perylene-3,4-dicarboximides which bear a sterically demanding substituent on the imide nitrogen atom by reacting a perylene-3,4:9,10-tetracarboxylic dianhydride with a sterically hindered primary amine in a substantially anhydrous reaction medium, which comprises undertaking the reaction in the presence of a tertiary amine, of a solvent based on a cyclic imine or amide and of a Lewis acid as a catalyst.

Abstract: Novel crystalline forms of and a process for converting perylene-3, 4:9, 10-tetracarboximide of the general formula I to a form used as a fluorescent dye. The process including: a) dissolving or suspending the perylene-3, 4:9, 10-tetracarboximide in a solvent to obtain a solution or suspension; and b1) cooling the solution obtained in step a) to a temperature at or below the crystallization temperature of the perylene-3, 4:9, 10-tetracarboximide and, if the solvent is organic, removing excess solvent until the first crystals form, otherwise, adding water or dilute aqueous solutions of the solvent until the first crystals form, and maintaining the solution at that temperature for further crystallization; or b2) cooling the suspension obtained in step a) to or below the crystallization temperature when the temperature in step a) was above the crystallization temperature, and maintaining the suspension at the temperature for further crystallization to form one or more solvate crystals.

Abstract: Novel crystalline forms of and a process for converting perylene-3,4:9,10-tetracarboximide of the general formula I to a form used as a fluorescent dye. The process including: a) dissolving or suspending the perylene-3,4:9,10-tetracarboximide in a solvent to obtain a solution or suspension; and b1) cooling the solution obtained in step a) to a temperature at or below the crystallization temperature of the perylene-3,4:9,10-tetracarboximide and, if the solvent is organic, removing excess solvent until the first crystals form, otherwise, adding water or dilute aqueous solutions of the solvent until the first crystals form, and maintaining the solution at that temperature for further crystallization; or b2) cooling the suspension obtained in step a) to or below the crystallization temperature when the temperature in step a) was above the crystallization temperature, and maintaining the suspension at the temperature for further crystallization to form one or more solvate crystals.

Abstract: A process for preparing quaterrylene-3,4:13,14-tetracarboximides of the general formula I in which R, R? are each independently hydrogen or optionally substituted C1-C30-alkyl, C5-C8-cycloalkyl or aryl or hetaryl; which comprises reacting a perylene-3,4-dicarboximide of the general formula IIa in the presence of a base-stable, high-boiling, organic solvent and of an alkali metal base or alkaline earth metal base, with a perylene-3,4-dicarboximide of the general formula IIb in which X is hydrogen, bromine or chlorine.

Abstract: A process for converting perylene-3,4:9,10-tetracarboximides of the general formula I in which R1 and R2 are each unbranched, branched or cyclic C1-C8-alkyl to a form suitable for use as fluorescent dyes, which comprises a) dissolving or suspending the perylene-3,4:9,10-tetracarboximides whose molecules have a molecular volume of ?230 ?3 in an organic or inorganic solvent at from 0 to 250° C.

Abstract: The current invention relates to a perylene-3,4-dicarboxylic anhydride, substituted in the 9-position, of the general formula III wherein Z is bromine or cyano, and processes for preparing 9-bromoperylene-3,4-dicarboxylic anhydride and 9-cyanoperylene-3,4-dicarboxylic anhydride.

Abstract: A process for preparing quaterrylene-3,4:13,14-tetracarboximides of the general formula I in which R, R? are each independently hydrogen or optionally substituted C1-C30-alkyl, C5-C8-cycloalky or aryl or hetaryl; which comprises reacting a perylene-3,4-dicarboximide of the general formula IIa in the presence of a base-stable, high-boiling, organic solvent and of an alkali metal base or alkaline earth metal base, with a perylene-3,4-dicarboximide of the general formula IIb in which X is hydrogen, bromine or chlorine.

Abstract: The current invention relates to a perylene-3,4-dicarboxylic anhydride, substituted in the 9-position, of the general formula III wherein Z is bromine or cyano, and processes for preparing 9-bromoperylene-3,4-dicarboxylic anhydride and 9-cyanoperylene-3,4-dicarboxylic anhydride.

Abstract: A 9-cyano-substituted perylene-3,4-dicarboxylic monoimide I where the variables are defined in the specification.

Abstract: A process for preparing perylene-3,4-dicarboximides which bear a sterically demanding substituent on the imide nitrogen atom by reacting a perylene-3,4:9,10-tetracarboxylic dianhydride with a sterically hindered primary amine in a substantially anhydrous reaction medium, which comprises undertaking the reaction in the presence of a tertiary amine, of a solvent based on a cyclic imine or amide and of a Lewis acid as a catalyst.

Abstract: Perylene derivatives of the general formula I where X and Y are independently oxygen, —NR1 or —NR2; R1 and R2 are independently hydrogen, C1–C18-alkyl, C5–C7-cycloalkyl, aryl or C1–C6-alkoxy; R3 to R10 are independently hydrogen, hydroxyl or aryl, although radicals conjointly attached to one carbon atom may also be ?O or ?CHR11, R11 is hydrogen or C1–C3-alkyl, with the proviso that said perylene derivative I contains from at least one to not more than three carbonyl groups per molecule.

Abstract: The invention relates to a method of producing color pastes, in which a component comprising colorant particles is dispersed in a binder. In the method of the invention the dispersing operation is controlled by beaming excitational light of a defined wavelength range into a mixture of the component comprising colorant particles and the binder, detecting the light transmitted, reflected and/or scattered by the mixture and determining a sample spectrum, evaluating the sample spectrum and hence determining parameters of the color paste, and monitoring changes in the sample spectrum over time and terminating the dispersing operation when predetermined target parameters are attained.

Abstract: A process for converting perylene-3,4:9,10-tetracarboximides of the general formula I in which R1 and R2 are each unbranched, branched or cyclic C1-C8-alkyl to a form suitable for use as fluorescent dyes, which comprises a) dissolving or suspending the perylene-3,4:9,10-tetracarboximides in an organic or inorganic solvent whose molecules have a molecular volume of ?230 ?3 at from 0 to 250° C.

Abstract: The invention relates to a cholesteric layered material with improved color shift stability.

Abstract: The invention relates to a method of producing color pastes, in which a component comprising colorant particles is dispersed in a binder. In the method of the invention the dispersing operation is controlled by beaming excitational light of a defined wavelength range into a mixture of the component comprising colorant particles and the binder, detecting the light transmitted, reflected and/or scattered by the mixture and determining a sample spectrum, evaluating the sample spectrum and hence determining parameters of the color paste, and monitoring changes in the sample spectrum over time and terminating the dispersing operation when predetermined target parameters are attained.

Abstract: Perylene derivatives of the general formula I 1

Abstract: Perylene derivatives of the general formula I where X and Y are independently oxygen, —NR1 or —NR2; R1 and R2 are independently hydrogen, C1-C18-alkyl, C5-C7-cycloalkyl, aryl or C1-C6-alkoxy; R3 to R10 are independently hydrogen, hydroxyl or aryl, although radicals conjointly attached to one carbon atom may also be ═O or ═CHR11, R11 is hydrogen or C1-C3-alkyl, with the proviso that said perylene derivative I contains from at least one to not more than three carbonyl groups per molecule.

Abstract: The invention relates to pyrazolone pigments of general formula (I), wherein the radicals R1, R2, R3 and R4 independently represent hydrogen, chlorine, methyl or ethyl, whereby at least one of the radicals R1-R4 is different from hydrogen. The inventive pigments are characterised by a CIELAB colour angle of 80-85°, a chroma of 58-62 and a luminosity ≧87 (measuring angle 45°, standard illuminant D65).

Abstract: The invention relates to pyrazolone pigments of general formula (I), wherein the radicals R1, R2, R3 and R4 independently represent hydrogen, chlorine, methyl or ethyl, whereby at least one of the radicals R1-R4 is different from hydrogen. The inventive pigments are characterised by a CIELAB colour angle of 80-85°, a chroma of 58-62 and a luminosity ≧87 (measuring angle 45°, standard illuminant D65).