GB2048294A

GB2048294A - New azo pigments

Info

Publication number: GB2048294A
Application number: GB8005556A
Authority: GB
Original assignee: Ciba Geigy AG
Current assignee: Novartis AG
Priority date: 1979-02-20
Filing date: 1980-02-19
Publication date: 1980-12-10

Abstract

The present invention provides new pigments having the formula <IMAGE> wherein R1, R2, R3, R4 and R5 are the same or different and each is hydrogen, C1-C4 alkyl, C1-C4 alkoxy, C6-C10 aryl, C6-C10 aryloxy, halogen, nitro, cyano, trifluoromethyl, -CO2R wherein R is hydrogen, C1-C4 alkyl or phenyl; -CONHR wherein R has its previous significance, -NHCOR wherein R has its previous significance, -SO2NHR wherein R has its previous significance, -SO2N(R6)2 wherein R6 is C1-C4 alkyl; or two ortho substituents from R1, R2, R3, R4 and R5 can combine to form an isocyclic or heterocyclic ring, which may itself contain an additional fused isocyclic or heterocyclic ring; n is 1 or 2; when n is 1, A is the residue of a diazotisable monoprimary 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 di- primary amine H2N-A2-NH2 wherein A2 is an arylene group, optionally substituted with up to four of C1-C4 alkyl, C1-C4 alkoxy, halogen, nitro or CO2-R.

Description

SPECIFICATION New azo pigments The present invention relates to new azo pigments derived from acetoacetylated arylureas.

According to the present invention, there are provided new pigments having the formula:

wherein R1, R2, R3, R4 and R5 are the same or different and each is hydrogen, Ci-C4 alkyl, C1-C4 alkoxy, C6-C10 aryl, C6-C10 aryloxy, halogen, nitro, cyano, trifluoromethyl, -CO2R wherein R is hydrogen, C1-C4 alkyl or phenyl; -CONHR wherein R has its previous significance, -NHCOR wherein R has its previous significance, -SO2NHR wherein R has its previous significance, -S02N(R6)2 wherein R6 isCi-C4 alkyl; or two ortho substituents from R,, R2, R3, R4 and R5 can combine to form an isocyclic or heterocyclic ring, which may itself contain an additional fused isocyclic or heterocyclic ring; n is 1 or 2; when n is 1, A is the residue of a diazotisable monoprimary amine A,NH2 wherein A, has the formula:

wherein P1, 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 with up to four of Ci-C4 alkyl, C1-C4 alkoxy, halogen, nitro, or CO2R wherein R has its previous significance.

When one or more of R, Rr, R2, R3, R4 and R5 are C1-C4 alkyl groups, they may be e.g. ethyl, isopropyl, n-propyl or n-butyl but are preferably methyl groups. Alkoxy groups P1, R2, R3, R4 and R5 may be e.g. ethoxy, isopropoxy, n-propoxy or n-butoxy groups but are preferably methoxy groups.

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

When two ortho groups P1, 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 P1, 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,', R2,, R3', R4,, R1, R2", R3", R4" are hydrogen, methyl, methoxy, chloro, nitro, cyano, trifluoromethyl, CO2R' wherein R' is hydrogen or methyl; -NHC0Ph, -S02NEt2; 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 pigments of formula I comprising coupling 1 mole of a diazonium salt or tetrazonium salt of a base of formula A(NH2)n wherein A and n have their previous significance, with n moles of a coupling component of formula:

wherein P1, R2, R3, R4 and R5 have their previous significance.

The coupling components of formula II may be prepared by the reaction of the appropriate arylurea with diketene, using procedures similar to those described by S. I. Zavyalov, I.A. Mikhailopolu, V.l. Gunnar and L.F. Ovechkina (Izv. Akad. Nauk SSSR Ser. Khim. 1967 (4), 859-63).

The coupling reaction may be 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, in an organic solvent, or in a mixture thereof.

Alternatively, the aqueous diazonium salt or tetrazonium salt solution or suspension and the coupling component solution or suspension may be added simultaneously to an aqueous buffer; or a solution or suspension of the coupling component may be gradually added to the solution or suspension of the diazonium ortetrazonium salt.

The coupling is suitably carried out at a pH in the range of from 3 to 7. Suitable buffers 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 surface active agents 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 alkylamines containing a C10--C20 chain.

Organic solvents which may be used include dimethylformamide, dimethyl sulphoxide and ethanol, but the preferred solvent is acetic acid.

The pigments may be isolated from 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 ethylcellulose, nitrocellulose, cellulose acetate, cellulose butyrate; natural resins or synthetic resins such as polymerisation resins or condensation resins, for example aminoplasts, especially urea-formaldehyde and melamine formaldehyde 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 illustrated by the following Examples.

Example 1 A suspension of 2-nitroaniline (5.7 g, 0.03 mol) in 1 M aqueous hydrochloric acid (100 ml) was stirred at 250C for 15 minutes and then cooled to OOC. A solution of sodium nitrite (21. g, 0.03 mol) in water (20 ml) was added dropwise over 5 minutes to the mixture kept at O-50C. The mixture was stirred for a further 75 minutes at 0--50C, treated briefly with activated charcoal (0.3 g) and filtered.

The resulting diazonium salt solution was added dropwise to a stirred solution of N-(acetoacetyl)-N'phenylurea (6.6 g, 0.03 mol) and anhydrous sodium acetate (15.9 g) in acetic acid (300 ml) at 25"C over 2.5 hours while the pH was kept in the range 4-5 by the simultaneous addition of 5M aqueous sodium hydroxide. The mixture was stirred for a further 90 minutes at 250C and then for 30 minutes at 900C. The greenish-yellow pigment was filtered, washed free of soluble salts with water and dried at 500.

Examples 2-60 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 which have the colour given. The pigments produced have the formula:

Example Amine ANH2 (n=1) R1 R2 R3 R4 R5 Colour 2 2-nitroaniline H H H H H Greenish-yellow 3 " Cl H H H H " 4 " CH3 H Cl H H " 5 4-chloro-2-nitroaniline H H H H H " 6 " CH3O H H H H " 7 " Cl H H H H " 8 " H H CH3 H H " 9 " CH3 H CH3 H H " 10 4-methoxy-2-nitroaniline H H H H H Reddish-yellow 11 " CH3O H H H H " 12 " Cl H H H H " 13 " CH3 H Cl H H " 14 " CH3O H Cl CH3O H " 15 " H H CH3 H H " 16 " CH3 H CH3 H H " 17 " CO2CH3 H H H H " 18 4-methyl-2-nitroaniline H H H H H Yellow 19 " CH3O H H H H " 20 " Cl H H H H Greenish-yellow

Example Amine ANH2 (n=1) R1 R2 R3 R4 R5 Colour 21 4-methyl-2-nitroaniline CH3 H Cl H H Yellow 22 " CH3O H Cl CH3O H " 23 " H H CH3 H H " 24 " CH3O H H SO2NEt2 H " 25 2-methoxy-4-nitroaniline H H H H H Greenish-yellow 26 " CH3O H H H H Yellow 27 " Cl H H H H " 28 " CH3 H H H H " 29 " CH3O H Cl CH3O H Reddish-yellow 30 5-diethylaminosulphonyl-2methoxyaniline H H H H H Greenish-yellow 31 2-chloro-4-nitroaniline H H H H H " 32 4-nitroaniline H H H H H " 33 anthranilic acid H H CH3 H H " 34 methylanthranilate CH3O H H H H " 35 2-cyanoaniline H H H H H " 36 2-chloro-5-trifluoromethylaniline Cl H H H H " 37 4-benzoylamino-2-methoxy-5methylaniline CH3 H CH3 H H Reddish-yellow 38 1-aminoanthraquinone H H H H H Yellow 39 " CH3O H H H H "

Example Amine (ANH2) (n=1) R1 R2 R3 R4 R5 Colour 40 1-aminoanthraquinone Cl H H H H Yellow 41 " H H CH3 H H " 42 " CH3 H CH3 H H Reddish-yellow 43 7-amino-4-methylquinol-2-one H H H H H Greenish-yellow 44 " CH3O H H H H Yellow 45 " H H CH3 H H " 46 " CH3 H CH3 H H Greenish-yellow Example Diamine NH2-ANH2 (n=2) R1 R2 R3 R4 R5 Colour 47 3,3'-dichlorobenzidine H H H H H Reddish-yellow 48 " CH3O H H H H " 49 " Cl H H H H " 50 " CH3 H Cl H H " 51 " CH3O H Cl CH3O H " 52 " Cl Cl H H H " 53 " H H CH3 H H " 54 " CH3 H CH3 H H " 55 " CO2CH3 H H H H " 56 " NO2 H H H H " 57 " CH3O H H SO2NEt2 H " 58 3,3'-dimethoxybenzidine H H H H H Orange 59 " CH3O H H H H " 60 " Cl H H H H " Example 61 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, C1-C4 alkyl, C1-C4 alkoxy, C6-C10 aryl, C6-C10 aryloxy, halogen, nitro, cyano, trifluoromethyl, -CO2R wherein R is hydrogen, C1-C4 alkyl or phenyl; -CONHR wherein R has its previous significance, -NHCOR wherein R has its previous significance, -SO2NHR wherein R has its previous significance, -SO2N(R6)2 wherein R6 is C1-C4 alkyl; or two ortho substituents from R1, R2, R3, R4 and R5 can combine to form an isocyclic or heterocyclic ring, which may itself contain an additional fused isocyclic or heterocyclic ring; n is 1 or 2; when n is 1, A is the residue of a diazotisable monoprimary amine A,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 with up to four of C1-C4 alkyl, C1-C4 alkoxy, halogen, nitro, or -CO2R wherein R has its previous significance.

2. Preferred pigments have the formula la or Ib:

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

or fl2 and R3' or R2" and R3" together are

R7 is methyl, methoxy or chloro.

3. A pigment of formula I substantially as described with reference to any of Examples 1 to 60.

4. A process for the production of a pigment of formula I comprising coupling 1 mole of a diazonium salt or tetrazonium salt of a base of formula A(NH2,n wherein A and n have their previous significance, with n moles of a coupling component of formula:

wherein R 1,R2,R3,R and R5 are as defined in claim 1.

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

6. A process of producing a pigment of formula I substantially as described with reference to any of Examples 1 to 60.

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.

10. A composition as claimed in claim 8 substantially as described with reference to Example 61.