DE1196619B - Process for the preparation of linear quinacridone of the ª † crystal form - Google Patents

Description

GERMAN

PATENT OFFICE

EDITORIAL

D06p

German class: Sm-13

Number;
File number:
Registration date:
Display day:

1196619
F27880IVc / 8m
March 6, 1959
15. JuU 1965

From US Pat. No. 2,844,581 it is known that the linear quinacridone of the formula

Process for the production of linear
Y-crystal form quinacridone

Applicant:

Farbwerke Hoechst Aktiengesellschaft

formerly Master Lucius & Brüning, Frankfurt / M.

which is obtained by oxidation of 6,13-dihydro-quinacridone with sodium m-nitrobenzenesulfonate in alcoholic sodium hydroxide solution, can be converted into a uniform crystal form (y-form). This uniform crystal form is characterized by three intense and four weaker lines in the X-ray diffraction diagram, which correspond to lattice plane spacings of 13.58, 6.41, 3.37, 6.70, 5.24, 4.33 and 3.74 Å. The conversion into the y-form is important because it is a bright blue-tinged-red pigment which is clearly superior to the raw quinacridone in terms of the brilliance of the coloring, the fastness properties, especially the light fastness and the color strength. To produce the y-phase, according to the US patent specification, the dry crude quinacridone is ground with 4 to 9 times the amount of an inorganic salt in a roller mill until a surface of at least 60m ² / g is reached, then moistened with dimethylformamide and that The whole thing is then boiled with dilute sulfuric acid, the pigment is separated off and dried. The salt milling can also be carried out in the presence of dimethylformamide. The known process requires the dry quinacridone to be ground, ie converted into a fine distribution, without which complete conversion into the desired y-form is not possible. It does not allow aqueous pastes in which the crude quinacridone is already in an extremely fine form, which is very suitable for conversion into a pure phase, to be converted directly into the desired crystal form. Rather, the individual particles must first be dried and thus inevitably made coarser, which must then only be reversed by salt grinding.

Crude quinacridones required for conversion to the y-form by the process of the invention

Named as inventor:

Dr. Otto Fuchs, Frankfurt / M.-Unterliederbach;

Dr. Alois Kirsch, Frankfurt / M.-Höchst

2

are suitable, e.g. B. obtained by condensation of 2,5-dianilinoterephthalic acid with Polyphosphoric acid, anhydrous hydrofluoric acid, aluminum chloride or titanium tetrachloride in trichlorobenzene or in a sodium chloride-aluminum chloride melt and subsequent hydrolysis of the reaction products obtained. The linear quinacridone obtained by this process is present its drying in extremely fine distribution in the form of an aqueous paste.

It has now been found that this finely divided crude quinacridone, present in the form of aqueous pastes, can be converted into the y-crystal form in a very simple manner without prior drying if the aqueous pastes are mixed with organic solvents with simultaneous removal of the water to temperatures of 100 to 200 ⁰ C heated. All organic solvents are suitable for generating the y phase, with the exception of the hydrocarbons and their halogen and nitro derivatives, which do not cause any conversion into the y crystal form.

It is expedient to proceed in such a way that the aqueous paste is placed in a stirred vessel in which there is so much of a suitable one organic solvent that a readily stirrable mixture is obtained, enters

509 600/323

ί 196619

and the water is distilled off with heating over several hours. When the water is gone increase the temperature and stir for a while. Depending on the type of solvent used the mass is then poured into water, diluted acid or methanol after cooling, the bright red dye is sucked off, washed, dried and pulverized. According to the specified The procedure obtained is a bluish-tinted red pigment of very soft grain, which is in the y-crystal form is present. It is ideal for coloring lacquers and plastic masses for which Production of printing inks and paints as well as for all other areas of application of organic Pigments and is in its coloring properties, its grain softness, its fastnesses and in terms of the brilliance of the color, it is considerably superior to the dried and ground raw quinacridone.

The method according to the invention has compared with the method of US Pat. No. 2,844,581 Advantage that it allows without drying and salt grinding to generate the y-crystal form directly. There salt grinding, in which 4 to 9 times the amount of an inorganic salt is used can only be carried out with low throughputs due to the limited size of the roller mills, the present process is a valuable addition to the technology.

You can also use another method, e.g. B. according to the information of the USA patent specification 2821 529 or according to Liebermann (Armalen der Chemie, 518 {1935], pp. 245 to 259) obtainable dried raw quinacridones by dissolving concentrated sulfuric acid, polyphosphoric acid or other tin Dissolve suitable substances in ejsüe fine distribution, then drove over the aqueous Pastes, the. subject to the invention process for generating the y-crystal form.

40

example 1

, 50 parts by weight of 2,5-terephthalic acid Pianiiino be hinacridon by heating at 120 to 130 ⁰ C in about 250 parts by weight of polyphosphoric acid having a content of PGOs, about 82 to 84% for the linear £ condensed Dip melt is hydrolyzed. The precipitated product is filtered off with suction and washed with water. To remove acidic constituents, the residue can be boiled with dilute alkali, optionally with the addition of ethyl alcohol. The product is then filtered off again and washed neutral with water. The moist crude quinacridone obtained in this way is stirred with 3W, part by weight of quinolih. The mixture is heated with stirring and the water aixtestillieri. \ ^ hen all the water is removed, it is heated for 3 hours at 180 ⁰ C. Then the mass jiiid cooled verdüüiite added to sulfuric acid is, the dye is washed with water äbgesaüft, Uli vacuum dried and pulverized to give am leücfttendpkusti ^ gJOtra pigment of the y- Kristaiifbrixi, the Läcip iiöd plastics in brilliant blue tinted Tönjäii with outstanding authenticity

i ^ nscitöfifen, fifrbt:,, 65

Ali place dps Chirioiins, one can with the same tfö ^ äucn butanediol (i, 4) or butyrolactone ver

55

turn around'.

Example 2

100 parts by weight of a 20% strength aqueous paste of finely divided crude quinacridone, which is obtained in the manner indicated in Example 1, are heated with 160 parts by weight of N-methylacetamide with stirring and the water is distilled off over the course of a few hours. The temperature is then increased to 130 to 140 ^° C. and stirring is continued for a few hours at this temperature. After cooling, it is diluted with water, filtered off with suction, washed well with water, dried in vacuo and pulverized. The bluish-tinged red pigment of the y-crystal phase obtained in this way is outstandingly suitable for coloring paints and plastic materials.

Is used instead of N-methylacetamide z. B. glycol, glycol monomethyl ether, glycol monoethyl ether, Diglycol monoethyl ether, glycerine, dimethylformamide or N-methylpyrrolidone is obtained in this way one the same pigment in the y-crystal form.

Example 3

In a pressure vessel 140 parts by weight of 2,5-dianilinoterephthalic acid are heated with 1000 parts by weight of anhydrous hydrofluoric acid 4 to 5 hours with stirring to 150 ⁰ C. Most of the hydrofluoric acid is distilled off and the residue is poured onto ice. The excess liquid acid is neutralized with sodium hydroxide solution, the pigment is then filtered off with suction and washed neutral with water. 300 parts by weight of the aqueous 20% paste of crude quinacridone obtained are stirred with 450 parts by weight of diglycol monoethyl ether and heated until the water has been removed. The mixture is then stirred for a few hours at 130 to 140 ^° C., the mass is then poured into water, filtered off with suction, washed with water, dried and ground. The red crystal powder obtained in the y-form colors paints and plastics in blue-green shades of excellent fastness properties.

Instead of the above-mentioned aqueous paste, it is also possible to use a paste made as follows is obtained:

200 parts by weight of 2,5 - Dianilina - terephthalic acid are condensed in a melt of 1000 parts by weight Alüminiumchlorid and 280 parts by weight of sodium chloride at 180 ⁰ C with stirring for linear quinacridone "The melt is hydrolyzed with 5000 parts by weight of ice and 500 parts by weight of 10% hydrochloric acid. The dye suspension is filtered off with suction and washed neutral with water.

Example 4

100 parts by weight of the 20% paste of raw chip acridone described in Example 1 are in a A stirred vessel containing 150 parts by weight of molten phenol is entered. The mixture wifd heated for several hours with stirring and the water was distilled off. Then the The temperature was increased and the mixture was stirred at 130 to 140 ° C. for a further 1 hour. After cooling, it is washed with methanol diluted, the mass filtered off with suction, washed well with methanol, dried in vacuo and pulverized. A red hgment of the y-crystal form is obtained, the Colors paints and plastics in bright blue-tinged red tones.

I 196619

Propionic acid can also be used in place of phenol. Benzyl alcohol, pyridine or aniline can be used.

Claims (1)

Claim: Process for the preparation of linear quinacridone of the y-crystal form, characterized in that that one aqueous pastes of finely divided crude quinacridone with organic solvents, with the exception of hydrocarbons and their halogen and nitro derivatives. to temperatures of 100 to 200 ° C under simultaneous Removal of the water heated. Considered publications:
U.S. Patent No. 2,844,581. A test report was displayed when the registration was announced.