摘要:
Process for the preparation of pigments of the anthanthrone series of the formula ##STR1## in which R.sub.1 and R.sub.2 denote chlorine, bromine or iodine atoms or C.sub.1 -C.sub.4 -alkoxy groups, having valuable properties, which comprises first converting the anthanthrones of the formula mentioned, in the form of the crude pigment, in an aqueous alkaline medium and at a pH>10, into the leucoform, precipitating the latter by adding inorganic or organic acids, reoxidizing the aqueous suspension of the leuco-form to give the anthanthrones and subjecting the resulting finely divided pre-pigments of the formula mentioned to a solvent finish.
摘要:
Process for the preparation of dry alkali metal salts of 1,8-naphthalimide, which comprises allowing concentrated alkali metal hydroxide solutions to run into solid 1,8-naphthalimide in a molar ratio, at a rate corresponding to the degree of reaction, with vigorous stirring in vacuo at an elevated internal temperature, and then carrying out drying without intermediate isolation of the alkali metal salt formed.
摘要:
Preparation of 3,4,9,10-perylenetetracarboxylic acid diimide by fusing naphthalene-1,8-dicarboxylic acid imide with potassium hydroxide and sodium acetate to give the alkali metal salt of the leuko compound of 3,4,9,10-perylenetetracarboxylic acid diimide, diluting the melt with water when the reaction has ended and oxidizing the leuko form to give the 3,4,9,10-perylenetetracarboxylic acid diimide, by a procedure which comprises(a) applying a vacuum of less than 100 mm Hg before the naphthalene-1,8-dicarboxylic acid imide is introduced into the potassium hydroxide/sodium acetate melt, heating the potassium hydroxide/sodium acetate mixture to 200.degree.-300.degree. C. and dehydrating it such that the melt is still stirrable at 200.degree.-220.degree. C., and then introducing the naphthalene-1,8-dicarboxylic acid imide or its sodium or potassium salt into the melt at 200.degree.-220.degree. C. under normal pressure and heating the mixture at 250.degree.-300.degree. C. in the absence of atmospheric oxygen, or(b) applying a vacuum of less than 100 mm Hg after the naphthalene-1,8-dicarboxylic acid imide or its sodium or potassium salt has been introduced into the potassium hydroxide/sodium acetate melt at 200.degree.-220.degree. C. under normal pressure, heating the mixture to 200.degree.-250.degree. C. and dehydrating it such that the melt is still stirrable at 200.degree.-220.degree. C., and then heating the melt at 250.degree.-300.degree. C. in the absence of atmospheric oxygen, or(c) introducing the sodium or potassium salt of naphthalene-1,8-dicarboxylic acid imide into the potassium hydroxide/sodium acetate melt at 200.degree.-220.degree. C. under normal pressure and heating the melt at 250.degree.-300.degree. C. in the absence of atmospheric oxygen.
摘要:
Very pure, transparent pigments of high color strength, of the formula ##STR1## in which R is hydrogen or alkyl having 1 to 4 C atoms, X is chlorine and/or bromine and n is a number from 0 to 4 are obtained by converting the corresponding crude pigment to the sulfate, isolating the sulfate, liberating the pure product from the sulfate by hydrolysis, separating off the pure product and dry milling the anhydrous material, with or without additives and with or without subsequent solvent finishing. These pigments are suitable for coloring paints and plastic compositions, especially for pigmenting metallic paints.
摘要:
Thioindigo and its derivatives are obtained in high yield and excellent purity by oxidizing corresponding 3-hydroxythionaphthenes with peroxo-disulfate in an aqueous alkaline solution.
摘要:
A process for the preparation of 4,4',7,7'-tetrachloro-thioindigo pigment which comprises treating a finely divided crude 4,4',7,7'-tetrachloro-thioindigo pigment in anhydrous form at temperatures of from 50.degree. to 180.degree. C. with a nitroaromatic substance which is volatile in steam and has a melting point of 50.degree. C. or below under normal conditions.
摘要:
Process for the preparation of perylene-3,4,9,10-tetracarboxylic dianhydride of high purity and in a very good yield in an ecologically unobjectionable manner, which comprises saponifying perylene-3,4,9,10-tetracarboxylic acid diimide with a 2.5-fold to 6-fold amount by weight of 92.5% to 97.5% strength sulfuric acid at temperatures of 210.degree. to 230.degree. C., washing the resulting mixture of perylene-3,4,9,10-tetracarboxylic dianhydride and perylene-3,4,9,10-tetracarboxylic acid monoanhydride-monoimide with a 0-fold to 4-fold amount by weight of 80-95% strength sulfuric acid, and then washing it with water until it is neutral, converting the compounds present in the mixture into their potassium salts by means of potassium hydroxide, after removing the perylene-3,4,9,10-tetracarboxylic acid monoanhydride-monoimide, adding to the solution of the tetrapotassium salt of perylene-3,4,9,10-tetracarboxylic acid, under nitrogen and with the exclusion of air and light, a salt of iron, nickel, calcium, magnesium, aluminum, tin, copper, lead, zinc or manganese, suspended or dissolved in water, and allowing this salt to act at a pH>10 and at temperatures from 0.degree. to 100.degree. C., then clarifying the mixture and converting the tetrapotassium salt of perylene-3,4,9,10-tetracarboxylic acid by acidification into perylene-3,4,9,10-tetracarboxylic dianhydride and isolating the latter in a customary manner.
摘要:
Process for preparing organic pigments having excellent application properties, which comprises treating finely divided crude pigments of the anthanthrone, pyranthrone, isoviolanthrone, azo, quinacridone, flavanthrone, indanthrone, naphthaldazine, indigo, thioindigo, tetracarboximide, dioxazine, isoindolinone, perylene, anthrapyrimidine, acylanthraquinone, dianthraquinonyl, azoanthraquinone, azomethineanthraquinone and phthalocyanine series at temperatures of 0.degree. C. to 100.degree. C., with acid esters of polyphosphoric acid and a primary, secondary or tertiary alkanol of 1 to 8 carbon atoms, a glycol, glycol ether or phenol, then hydrolyzing the polyphosphate ester used, heating the resultant aqueous mixture to temperatures of 20.degree. C. to 150.degree. C., and isolating the pigment in conventional manner.
摘要:
A perylene-3,4,9,10-tetracarboxylic acid dianhydride pigment, useful as a varnish pigment, made by adding an aqueous solution of an alkali metal salt of perylene-3,4,9,10-tetracarboxylic acid and a surfactant to an acid at a pH below 3, at 0.degree. C. to 90.degree. C., and then heating the suspension so obtained at 50.degree. C. to 150.degree. C.
摘要:
Process for preparing a strong, non-flocking and rheologically excellent 4,4',7,7'-tetrachlorothioindigo pigment in high yields and high purity, which comprises(a) reacting 2,5 -dichlorophenylthioglycoloyl chloride with Friedel-Crafts catalysts in inorganic acyl halides of medium oxidation state as diluent as temperatures of -20.degree. to +50.degree. C. to 4,7-dichloro-3-oxythionaphthene,(b) oxidizing the resulting 4,7-dichloro-3-oxythionaphthene in a conventional manner to crude 4,4',7,7'-tetrachlorothioindigo, and(c) treating the crude 4,4',7,7'-tetrachlorothioindigo obtained in moist form with an aromatic solvent at 80.degree. to 180.degree. C. in the presence of an aqueous alkali solution and a surface-active compound.