GB2047261A

GB2047261A - Azo pigments

Info

Publication number: GB2047261A
Application number: GB8005555A
Authority: GB
Original assignee: Ciba Geigy AG
Current assignee: Novartis AG
Priority date: 1979-02-20
Filing date: 1980-02-19
Publication date: 1980-11-26

Abstract

The present invention relates to new azo pigments derived from acetoacetylated amides. The present invention provides pigments having the formula:- <IMAGE> wherein R1, R2, R3, R4 and R5 are the same or different and each is hydrogen, 1-4C alkyl, 1-4C alkoxy, 6-10C aryl, 6-10C aryloxy, halogen, nitro, cyano, trifluoromethyl, -CO2R wherein R is hydrogen, 1-4C alkyl or phenyl; -CONHR wherein R has its previous significance, -NHCOR wherein R has its previous significance, -SO2NHR wherein R has its previous significance or -SO2(R6)2 wherein R6 is 1-4C alkyl; or two ortho substituents from R1, R2, R3 R4 and R5 together may form an isocyclic or heterocyclic ring which may itself contain an additional fused isocyclic or heterocyclic ring; n is 1 or 2 and; when n is 1, A is the residue of the diazotisable mono primary amine A1NH2 wherein A1 has the formula:- <IMAGE> wherein R1, R2, R3, R4 and R5 have their previous significance and; when n is 2, A is the residue of a tetrazotisable diprimary amine H2N-A2NH2 wherein A2 is an arylene group optionally substituted with up to four C1-C4 alkyl, C1-C4 alkoxy, halogen, nitrogen, nitro or -CO2R wherein R has its previous significance.

Description

SPECIFICATION Azo pigments The present invention relates to new azo pigments derived from acetoacetylated amides.

The present invention provides pigments having the formula:

wherein R1, R2, R3, R4 an@ R5 are the same or different and each is hydrogen, 1--4C alkyl, 1-4C alkoxy, 6-10C aryl, 6-10C aryloxy, halogen, nitro, cyano, trifluoromethyl, -CO2R wherein R is hydrogen, 1-4C alkyl or phenyl; -CONHR wherein R has its previous significance, -NHCOR wherein R has its previous significance, -SO2NHR wherein R has its previous significance or -SO2N(R6)2 wherein R6 is 1-4 C alkyl; or two ortho substituents from R1, R2, R3, R4 and R5 together may form an isocyclic or heterocyclic ring which may itself contain an additional fused isocyclic or heterocyclic ring; n is 1 or 2 and; when n is 1, A is the residue of a diazotisable mono primary amine A1NH2 wherein A1 has the formula:

wherein R1, R2, R3, R4 and R5 have their previous significance and; when n is 2. A is the residue of a tetrazotisable di-primary amine H,N-A2-NH2 wherein A2 is an arylene group, optionally substituted with up to four of C1-C4 alkyl, C1-C4 alkoxy, halogen, nitro, -CO2R wherein R has is previous significance.

When one or more of R, R1, R2, R3, R4 and R5 are 1-4C alkyl groups, they may be, e.g. ethyl, isopropyl, n-propyl or n-butyl groups but are preferably methyl groups. Alkoxy groups R1, R2, R3, R4 and R5 may be e.g. ethoxy, isopropoxy, n-propoxy or n-butoxy groups but are preferably methoxy groups.

Aryl cr aryloxy groups R1, R2, R3, R4 and R5 may be naphthyl or naphthyloxy groups respectively but they are preferably phenyl or phenoxy groups respectively. R6 may be e.g. isopropyl, n-propyl or n-butyl but is preferably methyl or ethyl.

When the two ortho groups R1, R2, R3, R4 and R5, together with the aromatic ring to which they are attached, form an isocyclic ring, such rings are e.g. naphthyl or anthraquinonyl rings. Examples of heterocyclic rings formed from two ortho groups R1, R2, R3, R4 and R5, together with the aromatic ring to which they are attached, are benzimidazolonyl and quinolonyl rings.

Arylene groups A2 are e.g. 1 ,4-phenylene, 1 ,5-naphthylene, and 1 ,5-anthraquinonylene, but are preferably 4,4'-biphenylene. Preferred pigments have the formula la or Ib:

wherein R5' and R5" are hydrogen, R,', F2,, R3', F4,, R,", R2", R3", R4" are hydrogen, methyl, methoxy, chloro, nitro, cyano, trifluoromethyl,--CO2R' wherein R' is hydrogen or methyl;--NHCOPh,--SO2NE2t; or R1, and R2' or R1" and R2" together are

or R2' and R3' or R2" and R3" together are

R7 is methyl, methoxy or chloro.

The present invention also provides a process of producing a pigment of formula I comprising coupling one mole of a diazonium salt or tetrazonium salt of a base of the formula A(NH2)n wherein A and n have their previous significance, with n moles of a coupling component of formula:

wherein F1, R2, R3, R4 and R5 have their previous significance.

The coupling component starting materials of formula II may be produced by reacting the corresponding amides with diketene, using procedures similar to those described by V. V. Perekalin and 0. M. Lerner, Zhur. Priklad Khim. 1956, 29, 1 609.

The coupling reaction is effected conveniently by gradually adding the aqueous diazonium salt or tetrazonium salt solution or suspension, to the solution or suspension of the coupling component, in a buffered aqueous medium, an organic solvent or mixtures thereof. Further convenient methods are to add simultaneously the aqueous diazonium (or tetrazonium) salt solution or suspension and the coupling component solution or suspension to an aqueous buffered medium; or to gradually add a solution or suspension of the coupling component to a solution or suspension of the diazonium (or tetrazonium) salt. The coupling is preferably effected in the pH range of from 3 to 7.

Examples of organic solvents which may be used are dimethylformamide, dimethylsulphoxide and ethanol, but the preferred solvent is acetic acid.

Examples of buffering agents which may be used are those derived from alkali metal salts of phosphoric acid or acetic acid.

The coupling medium may also contain surfactants to aid wetting and dispersion of the reactants and products. Examples of such surfactants are ethylene oxide condensation products of alkylated phenols e.g. the product of condensing nine moles of ethylene oxide with one mole of p-nonylphenol; sulphonated ethoxylated alkylphenols and their sodium salts; and 1 0-20C alkylamines.

The pigments may be isolated from the reaction mixture by filtration. Advantages may be obtained by heating the pigment slurry prior to filtration, alternatively, by subjecting the filter cake to solvent treatment or pressure treatment. Suitable solvents include o-dichlorobenzene, nitrobenzene, pyridine, dimethylformamide and N-methylpyrrolidone. The solvent treatment is carried out at temperatures from 100--2200C, whereupon the pigment particles undergo growth in many cases, which has a favourable effect on the fastness to light and migration properties.

The new colourants can be used in a finely divided form for pigmenting high molecular weight organic material, for example, cellulose ethers and esters such as ethyl cellulose, nitrocellulose, cellulose acetate, cellulose butyrate; natural resins or synthetic resins such as polymerisation resins or condensation resins, for example aminoplasts, especially urea-formaldehyde and melamineformaldehyde resins, alkyd resins, phenoplasts, polycarbonates, polyolefins such as polystyrene, polyvinyl chloride, polyethylene, polypropylene, polyacrylonitrile, polyacrylic acid esters, polyamides, polyurethanes or polyesters, rubber, casein, silicone and silicone resins, individually or as mixtures.

The pigments of the present invention are high strength bright yellow to orange pigments which are simple to prepare and have very low solubility in water.

The invention is further illustrated by the following Examples.

Example 1 A chilled solution of sodium nitrite (1.73 g, 0.025 mol) in water (20 ml) was added to a stirred suspension of 4-methoxy-2-nitroaniline (4.2 g, 0.025 mol) in 0.5M aqueous hydrochloric acid (200 ml) at 0--50C over 5 minutes. The mixture was stirred for a further 2 hours at 0--50C. The resulting diazonium salt solution was added dropwise over 90 minutes to a stirred solution of N-(acetoacetyl)-4methylbenzamide (5.48 g, 0.025 mol) and anhydrous sodium acetate (27 g) in acetic acid (300 ml) at 250C. The mixture was then stirred for a further 30 minutes at this temperature and then for 30 minutes at 900 C. The reddish-yellow pigment was filtered, washed free of soluble salts with water and dried at 500C.

Examples 2-61 Following procedures essentially the same as in Example 1 but using the appropriate amines and coupling components shown in the following Table, pigments were obtained having the colour given.

The pigments produced had the formula

Example Amine ANH2 (n=1) R1 R2 R3 R4 R5 Colour 2 2-nitroaniline H H H H H greenish-yellow 3 4-chloro-2-nitroaniline H H H H H " 4 " H H CH3O H H " 5 " H H NO2 H H " 6 " H H CH3 H H " 7 " Cl H Cl H H " 8 " H CH3O CH3O H H 9 4-methoxy-2-nitro- H H H H H reddish-yellow aniline 10 " C2H5O H H H H " 11 " H H CH3O H H " 12 " H H NO2 H H " 13 " C1 H C1 H H " 14 " H CH3O CH3O H H " 15 4-methyl-2-nitro- H H H H H Yellow aniline 16 " C2H5O H H H H " 17 " H H CH3O H H " 18 2,4-dinitroaniline H H H H H greenish-yellow 19 2-methoxy-4-nitro- H H H H H " aniline 20 " H H CH3O H H reddish-yellow 21 5-diethylaminosulphonyl-2-methoxy- H H H H H greenish-yellow aniline 22 2,4,5-trichloroaniline H H H H H "

Example Amine ANH2 (n=1) R1 R2 R3 R4 R5 Colour 23 2-chloro-4-nitroaniline H H H H H Greenish-yellow 24 4-nitroaniline H H H H H " 25 anthranilic acid H H CH3O H H " 26 methyl anthranilate H H CH3O H H " 27 2-cyanoaniline H H H H H " 28 2-chloro-5-trifluoromethylaniline H H H H H " 29 4-benzoylamino-2methoxy-5-methylaniline H H CH3 H H " 30 5-aminobenzimidazolone H H H H H Reddish-yellow 31 " H H CH3O H H " 32 " H H NO2 H H " 33 " H H CH3 H H " 34 " C1 H C1 H H " 35 7-amino-4-methyl-quinol2-one H H CH3O H H Greenish-yellow 36 " H H CH3 H H Yellow 37 " C1 H C1 H H Greenish-yellow 38 1-aminoanthraquinone H H CH3O H H Reddish-yellow 39 " H H NO2 H H Yellow 40 " H H CH3 H H Reddish-yellow DiamineNH2-A-NH2(n=2) 41 3,3-dichlorobenzidine H H H H H Reddish-yellow 42 " C2H5O H H H H " 43 " H H CH3O H H " 44 " H H NO2 H H " 45 " H H CH3 H H " 46 " C1 H C1 H H " 47 " H CH3O CH3O H H " 48 3,3'-dimethoxybenzidine H H H H H orange Example 49 The pigment as prepared in Example 1 was incorporated into a lithographic ink by dispersion of the sieved (60 mesh) pigment powder into a rosin modified phenolic varnish at 30% pigmentation.

Dispersion was achieved by an Ault and Wiborg Muller (4 x 100 revs.). The ink was drawn down on coated paper and assessed colouristically.

Claims

1. A pigment having the formula

wherein R1, R2, R3, R4 and R5 are the same or different and each is hydrogen, 1--4C alkyl, 1-4C alkoxy, 6-10C aryl, 6-1 OC aryloxy, halogen, nitro, cyano, trifluoromethyl, -CO2R wherein R is hydrogen, 1-4C alkyl or phenyl; -CONHR wherein R has its previous significance, -NHCOR wherein R has its previous significance, -SO2NHF wherein R has its previous significance or -S02N(F6)2 wherein R6 is 1-4C alkyl; or two ortho substituents from Ra, R2, R3, R4 and R5 together may form an isocyclic or heterocyclic ring which may itself contain an additional fused isocyclic or heterocyclic ring; n is 1 or 2 and; when n is 1, A is the residue of a diazotisable mono primary amine A1 NH2 wherein A1 has the formula:

wherein R1, R2, R3, R4 and R5 have their previous significance and; when n is 2, A is the residue of a tetrazotisable di-primary amine H2N-A2-NH2 wherein A2 is an arylene group, optionally substituted by up to four of C1-C4 alkyl, C1-C4 alkoxy, halogen, nitro, or -CO2R wherein R has its previous significance.

2. A pigment as claimed in claim 1 having the formula:

wherein R5' and R5" are hydrogen, R1', R2', R3', R4', R1", R2", R3", R4" are hydrogen, methyl, methoxy, chloro, intro, cyano, trifluoromethyl, -CO2R' wherein R' is hydrogen or methyl; -NHCOPh, -SO2NEt2; or R1' and R2' or R1" and R2" together are

or F2, and F3, or R2" and R3" together are

R7 is methyl, methoxy or chloro.

3. A pigment of formula I as claimed in claim 1 substantially as described with reference to any of Examples 1 to 48.

4. A process for the production of a pigment of formula I comprising coupling one mole of a diazonium salt or tetrazonium salt of a base of the formula A(NH2)n wherein A and n are as defined in claim 1, with n moles of a coupling component of formula:

wherein R1, R2, R3, R4 and F5 are as defined in claim 1.

5. A process as claimed in claim 4 wherein the coupling is effected in the pH range of 3 to 7.

6. A process of producing a pigment of formula I substantially as described with reference to any of Examples 1 to 48.

7. A pigment of formula I when produced by a process claimed in any of claims 4 to 6.

8. A composition comprising an organic material of high molecular weight and a pigmenting proportion of a pigment of formula I as claimed in any of claims 1 to 3.

9. A composition as claimed in claim 8 wherein the organic material is a cellulose ester or ether; a natural resin; a synthetic resin; rubber; casein; silicone or silicone resins; individually or as mixtures.

1 0. A composition as claimed in claim 8 substantially as described with reference to Example 49.