DD296293A5 - PROCESS FOR THE PRODUCTION OF MONOAZOPIGMENTS (9) - Google Patents

Abstract

The invention relates to a process for the preparation of monoazo pigments (9) of the general formula by azo coupling of diazotised 5-nitro-4-aminophthalimide to monoazo pigments. These are very useful for the inking of oil paints, varnishes, printing inks, plastics. formula

Description

Field of application of the invention

The invention enables the synthesis of monoazo pigments which can be used in oil paints, lacquers, printing inks and plastics for coloring.

Characteristic of the known state of the art

A number of inventions are known which describe the phthalimide ring in coupling and / or diazotization components as a constituent of monoazo and primary disazo pigments. In some of these descriptions of the invention, the 5-nitro-6-amino-phtha! Imid is listed as a diazo component.

Object of the invention

It is an object of the invention to produce monoazo pigments which meet the conditions of use.

Explanation of the essence of the invention

a) Technical task

The task is to use 5-nitro-4-amino-phthalimide as a diazo component for the preparation of monoazo pigments.

b) Features of the invention

When reworking the azo coupling of 5-nitro-4-amino-phthalimide to methylene-active compounds described in DE 2510373, US 4324719, CH 478205, we were only able to achieve dull hues, these dyes obtained being readily soluble even in dilute sodium carbonate solution. Spectroscopic investigations detected a previously overlooked circumstance. While phthalimides, which contain no nitro group in the 5-position, but substituents such as -H, -Cl, -Br ₁ -OCH ₃ , -OC ₂ H ₅ , in aqueous medium only above pH8 ring opening to the free dicarboxylic acid undergo this ring opening at 5-nitro-4-amino-phthalimide already slightly in the acidic range above pH3:

'CO

HOO <

In the case of the readily water-soluble diazinium salt, this ring splitting is still observed to be accelerated.

Some improvement is achieved by the use of naphthalenesulfonic acids during or after the diazotization reaction.

However, complete connection is only possible if the acidity of the coupling medium is kept below pH 3.

Furthermore, it is necessary to allow the coupling reaction to use particularly finely divided coupling emulsions and to couple at elevated temperature.

Any significant excess of not yet weggekuppelter diazonium compound must be avoided.

After the azo coupling is due to the now enlarged conjugated system, the tendency for ring opening sharply back, so that now even pH 8 at 60 ⁰ C is tolerated.

According to the invention, 5-nitro-4-amino-phthalimide of the formula

with coupling components K of the formulas

c *

R ₁ = -H ₁ -COCH-CONH ₂ ^ CONHaIkVl C ₁ ^, - CONHpheny ^ -NHCOCHa.-NHCOphenyl, -SO ₂ NH ₂ , -SO ₂ NH-alkyl C ₁ ^ ₄ ,

-SOzNHphenyl, -Cl, -OCH ₃ , -OC ₂ H ₅ , -CH ₃ R ₂ = same or different

R ₃ = -H, -alkyl C _M ,

, -naphthyl,

co.

R ₄ , Rs, Re = -H-CH ₃ , -OCH ₃ , -OC ₂ H ₆ , -O, -CONH ₂₁ -NHCOCh ₃ , -CONHalkyl (C ₁ - ^ - SO ₂ NH ₂ , -SO ₂ NH alkyl (C ₁ ^)

R ₇ = -H ₁ -CH ₂ -OC ₂ H ₅₁ -CI

R ₈ = -CH ₃ , -phenyl, -COOa-COOalkyl.-CONH ^ -CONHalkyl ^ CONHphenyl

Ky ₂ =O, S

in aqueous medium at pH 2-3 and temperatures up to +65 ⁰ C in the presence of surface-active substances to the monoazo pigments of the general formula according to the invention

wherein K has the meaning given above, implemented.

embodiments

example 1

10 ml of an aqueous solution containing V40 moles of the diazonium chloride of 5-nitro-4-aminophthalimide is introduced into a suspension prepared as follows at pH 2.5-3.0 within 50 minutes at 45 ° C in that the diazo component is undetectable. The pH is maintained with a sodium formate solution. Finally, it is heated to 70 ⁰ C and worked up.

10.8 g Acetoacetylamino ^ Adimethylbenzol are dissolved with 100 ml of ethanol and 9.0 ml of sodium hydroxide solution (32%) in 100 ml of water. This solution is added dropwise with vigorous stirring (e.g., with an "Ultra-Turrax") to a solution of 240 ml of water, 15 ml of formic acid and water

5 ml of Prohalyt 20/40 (VEB Buna-Werke Schkopau, East Germany, block polycondensate of ethylene aryl / propylene oxide, cloud point 58 ° C).

example

coupling component

nuance

1 acetoacetylaminobenzene yellow

2 acetoacetylaminobenzene-2-methylbenzene yellow

3 acetoacetylaminobenzene ^ -methylbenzene rotst.gelb

4 Acetoacetylaminobenzene ^ -methoxybenzene green. Yellow

5 acetoacetylaminobenzoM-methoxybenzene yellow

6 Acetoacetylaminobenzene ^ -methyl ^ '- chlorobenzene green. Yellow

7 acetoacetylaminobenzene-2-chloro-benzene green yellow

8 acetoacetylaminobenzene B-dimethoxybenzene redst.gelb

9 acetoacetylaminobenzene-2,5-dimethoxy-4-chlorobenzene reddish yellow

10 acetoacetylaminobenzene-2-methoxy-5-methyl-4-chlorobenzene redst.gelb

11 Acetoacetylaminobenzene ^^ - dimethylbenzene redst.gelb

12 acetoacetylaminobenzene-1-naphthamide red. Yellow

13 acetoacetylaminobenzene-2,4-bisacetylaminobenzene, brown yellow

14 acetoacetylaminobenzoM-carbamoylbenzene red. Yellow

15 S-acetoacetylaminobenzimidazolone ^) brown orange

16 4-Acetoacetylaminobenzimidazolone-phthalimide orange

17 e-Acetoacetylaminobenzimidazolone phthalazinedione orange

18 e-Acetoacetylaminobenzimidazolone-quinoxalinedione yellow-orange

19 S-Acetoacetylaminobenzimidazolone acridone yellow orange

20 i-Acetoacetylaminobenzimidazolone ^ S-bisacetylaminobenzene redst.gelb

21 acetoacetylaminobenzimidazolone ^ -bisacetylaminobenzene redst.gelb

22 Acetoacetylaminobenzimidazolone S-carbamoylbenzene Orange Yellow

23 phenylmethylpyrazolone brownish yellow

24 2 ', B'-dichloro-phenylmethylpyrazolone orange yellow

25 2'-chloro-phenylmethylpyrazolone redst.gelb

26 4'-Benzoylaminophenyl-3-methylpyrazolone yellow-brown

27 3-Carbethoxy-phenylpyrazolone orange

28 3-carbamoyl-phenylpyrazolone brown orange

29 2,4-dioxyquinoline yellow

30 barbituric acid orange

The pigments of the invention show colorations in the range greenish / yellow-orange-brown. Due to the high migration fastness and fastness to solvent and chemical attack, they are particularly suitable for incorporation into temperature-stressed paints and softened plastics.

Claims (1)

Invention claim: Process for the preparation of monoazo pigments, characterized in that the diazotization component is the amine of formula with coupling components K of the general formula CU ₃ , COHH-K ₃ tl With . R ₁ = -H, COOH, -CONH ₂ , -CONHalkyl C ₁ ^, -CONHphenyl, -NHCOCH ₃ , -NHCOphenyl, -SO ₂ NH ₂ , -SO ₂ NH-alkyl (C ₁ ^), -SO ₂ NHphenyl, -Cl, -CH ₃ , -OCH ₃ , -OC ₂ H ₅ R ₂ = the same or different than Ri R ₃ = -H, -alkyl CO ^ R ₄ , R ₅ , R ₆ = -H-CH ₃ , -OCH ₃ , -OC ₂ H ₅ , -C ₂ -CONH ₂ , -NHCOCH ₃ , -CONHalkyl (C ₁ ^) ₇ -SO ₂ NH ₂ , -SO ₂ NH-alkyl (C ₁ ^) R ₇ = -H, -CH ₃ , -OCH ₃ ^ OC ₂ H ₅ , -Cl R ₈ = -CH ₃ , -phenyl ^ -COOa-COOalkyl ^ CONHalkyl ^ CONH; ,, -CONHphenyl X1 / 2 = O, S to monoazo pigments of the general formula = N- K wherein K have the abovementioned meaning, are reacted in an aqueous medium at pH 3 to pH 2 and temperatures of from 0 to 65 ° C in the presence of surfactants and / or organic solvents.