Abstract: The present invention relates to a process for the preparation of dioxazine derivatives of the formula I ##STR1## in which R.sup.1 is hydrogen or (C.sub.1 -C.sub.8)-alkyl, by ring closure of a compound of the formula II ##STR2## in the presence of a ring-closure agent, wherein the ring-closure agent used is an N-hetarene N-oxide. The compounds of the formula I are used for producing valuable dyes and pigments.

Abstract: Process for the preparation of pigment preparations, which comprises wet milling the crude pigments which are present in coarsely crystalline state, or prepigments or pigments which are present in a form in which they are difficult to disperse, in a concentration of from 20 to 60% by weight based on the total weight of the pigment preparation, in a flocculation-stable liquid medium and in a stirred ball mill which is operated with a peripheral stirrer speed of more than 12 m/s, under the action of nonmetallic grinding media with a diameter of less than or equal to 1.0 mm, until the desired degree of fine division is reached, and then isolating the pigment preparation.

Abstract: Process for preparing linear unsubstituted .beta.-phase quinacridone pigments A process for preparing linear unsubstituted .beta.-phase quinacridone pigments or pigment preparations, which comprisesa) cyclizing 2,5-dianilinoterephthalic acid in polyphosphoric acid or polyphosphoric ester with a phosphorus pentoxide content of at least 84% by weight to form the quinacridone,b) subsequently hydrolyzing this quinacridone with water or with an aqueous mineral acid solution, preferably orthophosphoric acid solution, at a temperature of at least 40.degree. C., preferably from 60.degree. to 105.degree. C., to form the crude quinacridone pigment which is predominantly in the .alpha.-phase,c) then heating the crude .alpha.-phase quinacridone pigment to a temperature between 120.degree. and 200.degree. C. in the presence of a from 0.1 to 3% strength by weight, preferably from 0.

Abstract: A process for preparing quinacridone pigmentsA process for preparing pigments, mixed crystal pigments and pigment preparations based on linear unsubstituted or substituted quinacridones of the formula (I) ##STR1## in which the substituents R.sup.1 and R.sup.2 are identical or different and are hydrogen, chlorine, bromine or fluorine atoms or are C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy or carboxamido groups which may be substituted by C.sub.1 -C.sub.6 -alkyl groups; or are phenoxy or C.sub.6 -C.sub.10 -aryl rings onto which further aromatic, aliphatic or heterocyclic rings can be fused, which process comprises hydrolyzing the reaction mixture resulting from cyclization of the respective dianilinoterephthalic acid with polyphosphoric acid or polyphosphate at a temperature of or above 110.degree. C.

Abstract: The use of sulfuric monoesters of the formulae (I) and (II)R.sup.1 --O--(CH.sub.2 O).sub.n --SO.sub.3 .sup.- M.sup.+ (I)R.sup.1 --CO--NR.sup.2 --(CH.sub.2 O)(.sub.n+1)--SO.sub.3 .sup.- M.sup.+ (II)in whichR.sup.1 is a straight-chain or branched alkyl group of 10 to 24 carbon atoms,R.sup.2 is a hydrogen atom or a C.sub.1 -C.sub.6 -alkyl group,M.sup.+ is a hydrogen ion, an alkali metal ion, 1/2 an alkaline earth metal ion, or an ammonium ion of the formula N.sup.+ R.sup.3 R.sup.4 R.sup.5 R.sup.6, where the substituents R.sup.3, R.sup.4, R.sup.5 and R.sup.6 independently of one another are each hydrogen atoms or C.sub.1 -C.sub.6 -alkyl groups, which alkyl groups can be substituted by 1 to 3 hydroxyl groups, andn is a number from 0 to 4; or of a mixture of at least two sulfuric monoesters of the formulae (I) and/or (II),for preparing surface-treated pigments from the classes of the quinacridones and dioxazines.

Abstract: Readily dispersible polycyclic pigments from the class of the quinacridones and dioxazines are prepared by using a fatty acid tauride of the formula (I)R.sup.1 --CO--NR.sup.2 --(CH.sub.2).sub.n --SO.sub.3.sup.- M.sup.+(I)in whichR.sup.1 is a straight-chain or branched alkyl group having from 10 to 24 carbon atoms andR.sup.2 is a hydrogen atom or a C.sub.1 -C.sub.6 -alkyl group,M.sup.+ is a hydrogen ion, ammonium ion, alkali metal ion or alkaline earth metal ion and n is 1 or 2, or a mixture of at least two fatty acid taurides of the formula (I).

Abstract: Organic polycyclic crude pigments are finely divided in an ecologically and economically advantageous manner by first of all subjecting crude, coarsely crystalline pigments to dry milling and wet-milling the resulting finely divided prepigments in aqueous suspension in a stirred ball mill which is operated at a power density of more than 2.5 kW per liter of milling space and a peripheral stirrer speed of more than 12 m/s under the action of grinding media having a diameter of less than or equal to 1 mm. Pigments prepared in this way are particularly suitable as colorants for the pigmentation of paints, printing inks and plastics.

Abstract: Pigments, mixed-crystal pigments or pigment preparations based on linear, unsubstituted or substituted quinacridones are prepared advantageously by initially wet-milling the coarsely crystalline crude pigments in a liquid aqueous, aqueous-organic or organic medium in a stirred ball mill which is operated at a power density of more than 2.5 kW per liter of milling space and a peripheral stirrer speed of more than 12 m/s under the action of grinding media having a diameter of less than or equal to 0.9 mm, until the desired degree of fine division is reached, and then isolating the resulting pigment in a conventional manner, or subjecting the resulting prepigment to solvent treatment at a temperature of from 50.degree. to 200.degree. C. and then isolating the pigment in a conventional manner.

Abstract: A process for the preparation of 4,10-dibromoanthanthrone pigment, which comprises first subjecting the crude 4,10-dibromoanthanthrone pigment, which is in the coarsely crystalline state, to wet milling in an aqueous medium in a stirred ball mill which is operated at a power density of more than 2.5 kW per liter of milling space and at a peripheral stirrer speed of more than 12 m/s under the action of grinding media with a diameter of less than 1.0 mm, until the desired degree of fine division is reached (millbase suspension), and then isolating the resulting pigment in a conventional manner; or subjecting the prepigment obtained in the wet milling to a treatment at elevated temperature (finish) in an aqueous medium, an aqueous-organic medium or a liquid aromatic compound, and then isolating the pigment.

Abstract: Linear, unsubstituted quinacridone pigments of the .beta.-phase can be produced in an environmentally friendly manner bya) cyclizing 2,5-dianilinoterephthalic acid in polyphosphoric acid or a polyphosphoric ester to the quinacridone,b) then hydrolyzing the quinacridone with water at a temperature of at least 40.degree. C., preferably at from 60.degree. to 100.degree. C., to obtain a finely divided quinacridone pigment crude which is predominantly in the .alpha.-phase,c) then optionally wet grinding the finely divided quinacridone pigment crude from b) (pre-pigment), andd) then heating the crude pigment from b) or the pre-pigment from c) to a temperature between 120.degree. and 200.degree. C. in the presence of from 0.1 to 1.5 times the amount of an inorganic base, based on the weight of the crude pigment, in an inert liquid medium (solvent finish).To improve the depth and hue of the color, an oxidative treatment with a peroxodisulfate can be carried out subsequently.

Abstract: Copper phthalocyanine pigments are finely divided in an ecologically and economically advantageous manner by first of all subjecting crude, coarsely crystalline copper phthalocyanine pigments to dry milling and then wet milling the finely divided prepigments which are obtained in the course of dry milling, in aqueous suspension and with the addition of from 0.1 to 5% by weight, based on the total millbase, of an organic solvent which is inert with respect to the process conditions, on a stirred ball mill which is operated at an energy density of more than 2.5 kW per liter of milling space and a peripheral stirrer speed of more than 12 m/s under the action of grinding media having a diameter of less than or equal to 1 mm. Copper phthalocyanine pigments prepared in this way are particularly suitable as colorants for pigmenting paints, printing inks and plastics.

Abstract: Novel perylene compounds based on perylene-3,4,9,10-tetracarboxylic acid monoanhydride monoimides which are substituted by alkylene- or arylenesulfonic acid groups on one or both imide nitrogen atoms, or on corresponding tetracarboxylic acid diimides, or on a halogenation product thereof, have properties which render them accessible, in addition to their use as dispersing agent for pigments of the same class of compound or other categories, also for direct use as pigments and fluorescent dyestuffs as well as polymer-soluble dyestuffs.

Abstract: In conventional dry milling of C.I. Pigment Violet 23, the environment is heavily polluted by the necessarily formed dusts, the resulting noise and vigorous vibration during the milling process.According to the invention, it has now been found that these shortcomings can be avoided by carrying out the comminution of the base pigment by aqueous-alcoholic milling in the presence of beads and selected pigment dispersants derived from dioxazine compounds containing basic groups, followed by a solvent finish.Such a combination of the two abovementioned treatment operations even makes it possible to increase the capacity without the need for any other expensive investments for constructional modifications of the equipment.

Abstract: Copper phthalocyanine pigments and pigment preparations in the .alpha. phase are prepared with phase conversion from copper phthalocyanine crude pigments of the .beta. phase in an environmentally safe and economical manner bya) first wet milling a copper phthalocyanine pigment, which is predominantly present in the .beta. phase, in an aqueous, preferably neutral to alkaline medium in a stirred ball mill which is operated at a power density of more than 2.

Abstract: Phthalocyanine pigments and phthalocyanine pigment preparations in the .alpha. phase and in the .beta. phase are prepared with phase conservation in an environmentally safe and economical manner bya) first wet milling a phthalocyanine pigment in an inert liquid medium in a stirred ball mill which is operated at a power density of more than 2.

Abstract: In order to improve the application properties, in particular the rheological and coloristic properties, and the gloss behavior and the flocculation stability of dioxazine pigments in acrylic varnishes, the surface of the base pigment is modified by coating with sulfo-containing dioxazine derivatives, which in most cases have been converted into the corresponding metal salts, into specific salt-like derivatives derived therefrom or, if desired, into cyclic ammonium compounds. Such a modification of the base pigment, i.e. production of the pigment preparations according to the invention by adding the specific dispersant, can take place at the stage of the pigment synthesis, during a comminution process of the coarse-crystalline crude pigment, by addition to the already finely divided crude pigment in the course of a subsequent solvent finish treatment or by mechanical mixing of the two essential components, pigment and dispersant.

Abstract: Pigment preparation essentially comprisinga) at least one pigment from the class of azo, anthrapyrimidine, anthanthrone, quinacridone, perinone, diketopyrrolopyrrole, dioxazine, flavanthrone, indanthrone, isoindolinone, isoviolanthrone, perylene, phthalocyanine, pyranthrone or thioindigo pigments or a mixture of pigments belonging to various classes, andb) at least one dispersant of the formula (I) ##STR1## in which P, independently of the pigments mentioned in a), is a radical of an anthanthrone azo, quinacridone, perinone, diketopyrrolopyrrole, dioxazine, indanthrone, perylene, phthalocyanine or thioindigo pigment,R.sup.1 and R.sup.2, independently of one another, are hydrogen, halogen, C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.

Abstract: Pigment preparations consisting essentially of (a) at least one pigment based on perylene-3,4,9,10-tetracarboxylic dianhydride or on corresponding monoimides or diimides of tetracarboxylic acid monoanhydride, or a halogenation product thereof, (b) at least one pigment dispergent based on perylene-3,4,9,10-monoimide substituted on one or both imide nitrogen atoms by alkylene or arylene sulphonic or carboxylic acid groups or on corresponding diimides of tetracarboxylic acid monoanhydride, or a halogenation product thereof. The dispergents used appreciably enhance the key properties of perylene pigments, such as dispersibility, coloring power, stability to flocculation, transparency, rheological behavior and surface properties of the application medium. These new preparations are suitable for the pigmentation of high-quality lacquers and synthetic resins.

Abstract: Perylenetetracarboxylic diimides which contain a radical in the same molecule on one imide nitrogen which acts as an anion but contain a radical on the other imide nitrogen which acts as a cation, and on this basis form inner salts, are available by reaction of sulfo-containing alkylamines with perylenetetracarboxylic monoanhydride monoalkylaminoalkylimides or by reaction of alkylaminoalkylamines with perylenetetracarboxylic monoanhydride monosulfoalkylimides. As a result of their characteristic structural principle, these novel perylene compounds have excellent dispersing properties, in particular for pigments of the same chemical classes of compounds and can even be used themselves as pigments (colorants) depending on the substituent.

Abstract: In the art of pigmenting high molecular weight organic materials there is a long-felt need for high-hiding organic red pigments, in particular yellowish red pigments, which are increasingly used to replace the ecologically unsafe inorganic red pigments. However, this gap in the market cannot be satisfactorily filled by using the tetrachloroperylenetetracarboximide pigments known for the aforementioned purpose.According to the invention, it has now been found that a chlorine content of .ltoreq.25% in such chlorinated perylimides confers remarkable coloristic properties on the pigments thus produced, so that these pigments are superior in hiding powder and masstone to the tetrachloroperylimide compounds described. Accordingly, the invention is directed to high-hiding red pigments of the type of the halogenated perylenetetracarboximides containing up to 4 chlorine atoms, whose chlorine content is 15-25% and which are present as mixed crystal pigments in the .beta.