DE1199906B - Process for the preparation of linear quinacridones - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

C09b

German class: 22 e- 7/02

Number: 1199 906

File number: F 32092IV c / 22 e

Filing date: September 10, 1960

Opening day: September 2, 1965

From the Belgian patent 579 525 a process for the preparation of linear quinacridones is became known, which consists in the fact that one compounds of the general formula

Method of making linear
Quinacridones

R ₉ -HN,

R ₁ OOC

COOR ₁

NH-R,

in which R ₁ is a hydrogen atom, an aliphatic or aromatic radical and R ₂ is an aryl radical in which at least one o-position to the NH group is not substituted, cyclized with polyphosphoric acid at temperatures of 150 to 25O ⁰ C. According to the process of this patent specification, the free 2,5-diarylaminoterephthalic acids or their alkyl or aryl esters are subjected to the ring closure reaction.

As is known from the literature, the linear quinacridones are very suitable for dyeing Lacquers and plastic masses. The products have excellent light and solvent fastness. The unsubstituted linear quinacridone comes as from U.S. Patents 2,844,484, 2,844,485 and 2,844,581 appear in three different crystal forms. Only in the form of the pure crystal forms the linear unsubstituted quinacridone shows the optimal fastness properties.

Amorphous or those products that consist of mixtures of the individual crystal forms are the pure ones Crystal forms in fastness properties, applicability and purity of shade inferior.

In the French patents 1,254,049 and 79,177 and in the German Auslegeschrift 1,150,046 processes are described which allow the moist crude quinacridone, as is obtained in the cyclization of free 2,5-dianilinoterephthalic acid with polyphosphoric acid, directly without prior To transform intermediate drying into the pure ß- or y-crystal form.

The ring closure is of decisive importance for the perfect success of this transformation to be carried out in such a way that in the case of the unsubstituted quinacridone a crude product is formed which is smooth can be converted into the individual desired crystal forms. Furthermore, in the case of the substituted Quinacridones the ring closure conditions are chosen so that pigments with the greatest possible purity result, since in practice great importance is attached to a high level of brilliance in the color shade. When the ring closes Applicant:

Farbwerke Hoechst Aktiengesellschaft
formerly Master Lucius & Brüning,
ίο Frankfurt / M.

Named as inventor:

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

Dr. Alois Kirsch, Frankfurt / M.-Höchst

ao of 2,5-Diarylaminoterephthalsäureester with PoIyphosphorsäure at 150 to 250 ⁰ C according to the process of the Belgian Patent 579 525, this is not the case, however. The products obtained are markedly more cloudy in color and, in the case of the unsubstituted quinacridone, can no longer be converted into the pure crystal forms, which works perfectly with the crude quinacridone, which is obtained by ring closure of the free 2,5-dianilinoterephthalic acid. Only after laborious cleaning do the linear quinacridones produced from the esters obtain the desired purity and brilliance of the color. The esters are therefore ruled out from the outset for the rational production of linear quinacridones with the aim of using them as pigments. In order to achieve useful results, one is therefore forced to prepare the free diarylaminoterephthalic acids when working according to the process of Belgian patent 579 525. This is done in such a way that the 2,5-diarylaminoterephthalic acid esters are saponified with alcoholic alkali and the free 2,5-diarylaminoterephthalic acids are then precipitated with mineral acids, separated off, washed neutral and dried.

It has now been found that the alkali salts of 2,5-diarylaminoterephthalic acids can be used instead of the free acids from the general formula

R ₁ -HN

COOX

XOOC ~ ^ NH-R ₁
in which X is a sodium or potassium atom and R _{1 is} one

509 659/425

3 4

Aryl group, still by halogen atoms, from 125 to 13O ⁰ C and stirred at this temperature for about

Alkyl, alkoxy, aryloxy, acylamino or aryl 1 hour. After cooling, the melt becomes

groups can be substituted, particularly advantageous by adding 3000 parts of water and 6000 parts

Adherently hydrolyzed ice for cyclization with polyphosphoric acid. The reaction material is filtered off with suction with a P ₂ O ₅ content of 83 to 86 percent by weight and washed neutral with water. You get

at temperatures between 120 and 140 ⁰ C use 305 parts by weight of linear quinacridone as about 20%

can. 305 parts by weight of linear quinacridone as about

It was not foreseeable that the alkali salts would be 20% aqueous residue. In this form it is

of 2,5-diarylaminoterephthalic acids such as the free linear quinacridone are ideally suited for

Acids themselves would be suitable for ring closure, since they lead to the pure β and γ crystal phases.
when converting some of the polyphosphoric acid into

their alkali salt is transferred. It was therefore to be B eis ρ ie 1 2
wait for the presence of the alkali salt

Ring closure would interfere in such a way that either 112 parts of dry sodium salt of the 2,5-dianilino-

Crude terephthalic acid that is no longer convertible or cloudy becomes 1500 parts ^{at 80 to 90 ° C.}

quinacridones are obtained. Polyphosphoric acid with a P ₂ O ₂ content of 85.5%

The ring closure is expediently carried out in this way, stirred. The temperature is maintained at 125 to 130 ⁰ C. gedaß the bone dry alkali metal salt at about 8O ⁰ C and held increases I ¹ U hour. After cooling, the mixture is stirred in polyphosphoric acid, then the melt ^{is heated to about 100 °} C., the melt is heated to 4000 parts of ice from 120 to 130 ^° C. and 20 and 1000 parts of water are added for about 1 hour. The reaction product maintains its temperature. After cooling, it is filtered off with suction and washed neutral. After remelting, hydrolyzed by pouring into ice water, conversion into the y-crystal form, 85 parts of the precipitated crude quinacridone are then filtered off. a bright red powder that is washed neutral with and next to water. the well-known excellent fastness properties

The alkali salt used for the ring closure can 25 characterized by its high opacity,
can be produced in a particularly simple way. the

2,5-Diarylaminoterephthalic acid esters are produced by Example 3
brief heating in an alcoholic solution with the

calculated amount of sodium or potassium hydroxide. 122 parts of the potassium salt of the

saponified, the yellow solution obtained is used to remove 30 2,5-dianilinoterephthalic acid in 1000 parts of polyphosphate

tion of any impurities that may be present filtered phosphoric acid with a P ₂ O ₅ content of 84.2% and

and in an apparatus suitable for this purpose up to leads to the ring closure and the work-up, as in

Evaporated to dryness. Example 2 is obtained in this way, described by. 85 bis are obtained

directly the dry alkali salts of the 2,5-diarylamino- 87 parts of linear quinacridone as about 20% aqueous

terephthalic acids, which are in the present form 35 riges reaction product, which is in the present

can be easily cyclized with polyphosphoric acid. That shape is especially good for a conversion into that

unsubstituted quinine β and y crystal form obtained after the cyclization is suitable,
acridon is very suitable for converting into the

/ S and y crystal forms. The substituted quinacridones Example 4

are obtained in optimal purity and are suitable after 40

the drying and corresponding fine division 60 parts of the sodium salt of 2,5-di- (4'-methyl-

excellent as pigment dyes. anilino) -terephthalic acid are used according to the information

Compared to the process of the Belgian patent of Example 2 with 420 parts of polyphosphoric acid with writing 579 525, the process _{according to the invention has a P 2} O ₅ ratio of 83.9% cyclized. The advantage is that the much easier to produce 45 44 parts of the corresponding methyl-substituted linear alkali metal salts of 2,5-diarylaminoterephthalarene quinacridones are obtained, which after fine acidification directly with polyphosphoric acid in the quin division excellent for the coloration of lacquers and have acridone transferred. Another advantage plastic compounds are suitable.

it says that the amount of alcohol that is used in place of the sodium salt of the

Saponification of the 2,5-diarylaminoterephthalic acid ester 50 2,5-di- (4'-methylanilino) -terephthalic acid 64 parts of the

are required, in the case of processing on the sodium salt of 2,5-di- (4'-fluoroanilino) -terephthal-

Alkali salts practically lossless and much more simply acidic or 69 parts of the sodium salt of the 2,5-di-

let regenerate than when processing to the (4'-chloroanilino) -terephthalic acid, 50 parts are obtained

free acids. of the corresponding fluorine or 54 parts of the chlorine sub-

The parts and 55 substituted linear quinacridones given in the examples. Both pigments color

Percentages are units of weight. ben after drying and fine distribution paints and

three-dimensional masses in lively red-violet tones.
example 1

Example 5

404 parts of 2,5-dianilinoterephthalic acid diethyl ester 60

are boiled for 1 hour with a solution In 574 parts of polyphosphoric acid with a P ₂ O ₅ -Ge

81 parts of sodium hydroxide in 1200 parts of metha holding 82 parts of the saponified nol at 80 to 90 ⁰ C of 83.9%. The yellow solution obtained is filtered using the sodium salt of 2,5-di- (2'-methoxyanilino) -tere- and stirred into phthalic acid in a suitable apparatus in vacuo. The temperature is evaporated to dryness. The sodium salt is then increased to 65 115 to 120 ⁰ C and held for 1 hour. The 2600 parts of polyphosphoric acid with a P ₂ O ₅ content, cooled to 110 ⁰ C, is hydrolyzed by introducing 83.8% at 80 to 90 ° C with exclusion of moisture into 1200 parts of ice and 600 parts of water, stirred. The temperature is slowly increased to the precipitated reaction product, filtered off and neutral

washed. After suitable fine division, 59 parts of methoxy-substituted quinacridone are obtained Coloring of paints and plastic masses in red tones is suitable.

Example 6

53 parts of the sodium salt of 2,5-di- (2'-chloroanilino) - terephthalic acid within 10 minutes in 370 parts of 90 to 100 ⁰ C hot polyphosphoric acid having a P ₂ O ₅ content of 83.3% was added. The reaction mixture is heated to 140 ° C. and stirred at this temperature for 2 hours. The melt is poured onto 750 parts of ice and 350 parts of water, and the reaction mixture is filtered off and washed until neutral. After drying and fine distribution, 39 parts of chlorine-substituted quinacridone are obtained, which dyes paints and plastic materials in bright red shades.

Example 7

^v ao

30 parts of the sodium salt of 2,5-di- (4'-phenoxyanilino) -terephthalic acid are introduced into 210 parts of polyphosphoric acid at 70 to 80 ° C. with a P ₂ O _{5 ratio of 83.9%, with stirring.} The mixture is then stirred at 120 to 125 ° C. for a further 1 hour. After working up the reaction mixture according to Examples 5 and 6, 23 parts by weight of the corresponding quinacridone are obtained which, when finely divided, dyes paints and plastic compositions in blue-violet shades.

Claims (1)

Claim: Process for the production of linear quinacridones, characterized in that that the alkali salts of 2,5-diarylaminoterephthalic acids of the general formula R ₁ -HN COOX COOX NH-R ₁ in which X is a sodium or potassium atom and R _{1 is} an aryl radical which can also be substituted by halogen atoms, alkyl, alkoxy, aryloxy, acylamino or aryl groups, with polyphosphoric acid having a P ₂ O ₆ gel from 83 to 86 percent by weight of cyclized at temperatures between 120 and 140 ⁰ C. Considered publications:
Belgian patent specification No. 579 525. When the application was announced, two coloring tables with explanations were laid out. 509 659/425 8.65 © Bundesdruckerei Berlin