GB2039515A - Azomethine pigments - Google Patents

Abstract

Novel azomethine pigments have the formula: <IMAGE> wherein A and B are the same or different and are aryl or heterocyclic radicals optionally substituted by non- water-solubilising groups, R represents hydrogen, an alkyl, cycloalkyl, aryl or aralkyl radical, X is CO2 or SO3, Y is hydrogen, CO2<???> or CONHR<1> where R<1> is hydrogen or an alkyl, aryl or heterocyclic radical, L is a donor ligand containing oxygen or nitrogen, M is a divalent metal atom and x is 0 to 6.

Description

SPECIFICATION Azomethine pigments The present invention relates to metal-organic compounds and, in particular, to substituted azomethine compounds having valuable pigmentary properties. The present invention relates in particular to azomethine colouring matters suitable for the pigmentation of paints, lacquers, printing inks, rubber, artificial polymeric materials, paper and textile materials and to processes of producing these azomethine substances.

Accordingly the present invention provides azomethine complexes of the general formula I:

wherein A and B are the same or different and are either aryl or heterocyclic residues optionally substituted by non-water solubilizing groups, R is'hydrogen, an alkyl, cycloalkyl, aryl or aralkyl residue, Xis CO2 or S03, Y is hydrogen,CO2- or CONH-R' where R1 is hydrogen or an alkyl, aryl or heterocyclic residue, Lisa donor ligand containing oxygen or nitrogen, x represents the number of molecules of Land is in the range 0 to 6 and M is a divalent metal atom.

When L is a donor containing oxygen it is preferably a neutral donor, such as water, ethanol, tetrahydrofuran or dimethyl sulphoxide. When Lisa donor containing nitrogen it may be, for example, ammonia or pyridine.

Divalent metal M may be selected from Mg, Ca, Mn, Fe, Co, Ni, Cu, Zn, and Cd.

When A andior B is an aryl residue, the latter preferably contains from 6 to 14 carbon atoms and may consist of a single aromatic ring or two or more fused aromatic rings. The aryl residue may be unsubstituted or substituted with one or more groups which do not impart water-solubility to the complex compound of formula I or II, for instance alkyl, alkoxy, carboxyalkyl or alkylcarbamoyl groups, each having from 1 to 4 carbon atoms in the alkyl moiety, aryl, aryl-carboxyarylamide, arylcarbamoyl groups, nitro groups or halogen atoms. Preferred examples of aryl residues A and/or B are phenyl and naphthyl residues.

When A and/or B is a heterocyclic residue, it may be either unsubstituted or substituted with one or more of the non-water-solubilising groups disclosed hereinbefore. Preferred heterocyclic residues A and/or B are pyrazol-5-one residues.

The preferred system is that wherein A is a naphthalene residue and Y is CO2-, thereby providing compounds of the following formula:

wherein R1' is a hydrogen or a non-water-solubilising group, for example, halogen, alkyl or alkoxy group each having one to four carbon atoms, nitro, aryl and alkyl- or aryl-carbamoyl. B, R, X, M, Land x have their previous significance.

The especially preferred system is that wherein B is a phenylene residue, thereby providing compounds of the following formula:

wherein P111 is a hydrogen or a non-water-solubilising group and R, R11,X, M, Land x have their previous significance.

The present invention also provides a process in which a compound of formula I is produced comprising the metallisation of the ligand of the following formula:

wherein A, B and R have their previous significance. The metallisation of the compound of formula IV may be carried out directly or, after production, the ligand may be filtered off, washed and resuspended in the same or different solvent prior to metallisation. The metallisation may be effected using a solution or suspension of any suitable metal salt or complex, for example, the acetate. The reaction may be carried out under a wide variety oF conditions, but conveniently the azomethine of formula IV is heated with the metallising agent at a temperature within the range ambient to 100"C. and at a pH of 8 - 9.The reaction may be carried out in aqueous solution or in a water-alcohol mixture or in any organic solvent that is substantially inert under the conditions of the reaction, for example, dimethyl formamide, pyridine, dimethyl sulphoxide or Nmethylpyrrolidine The ligand of formula IV may be prepared by the reaction of a keto component having the formula:

wherein A and R have their previous significance, with an amino component having the formula:

wherein X and B have their previous significance.

The especially preferred keto components are of the formula:

wherein R and R' have their previous significance.

The especially preferred amino components are of the formula:

wherein X and R" have their previous significance. Examples of amino compounds which may be used to produce products of especial value as pigments are 2-amino 4-methyl 5-chloro benzene sulphonic acid, 2-amino 1-naphthaiene sulphonic acid, anthranilic acid and 2-amino 5-nitro benzoic acid.

The compounds of formula I may be employed as pigments directly after production; that is after they have been filtered off from their crude reaction liquors and dried. Alternatively, they may be first processed using known wet or dry conditioning techniques, such as grinding, either alone or in the presence of a water-soluble salt or other medium which can be subsequently removed, for instance by washing.

Accordingly, the present invention further provides a method of colouring organic material by incorporating therein a substituted azomethine compound of formula I, together with organic materials when so coloured.

Organic materials suitable for treatment according to the method of the present invention includes, for example, surface coatings such as inks, lacquers and paints, natural synthetic polymers and plastics, paper and textile materials. In general, the pigments of this invention exhibit good fastness properties, especially to light, heat, cross lacquering and migration and resistance to organic solvents such as trichloroeoethylene, toluene and methyl ethyl ketone.

Specific organic materials which may be coloured according to the invention include high molecular weight organic material, for example, cellulose ethers and cellulose esters, such as ethyl cellulose, acetylcellulose and nitrocellulose, synthetic polyamides, polyurethanes and polyesters, natural and synthetic resins, such as aminoplasts, especially urea-formaldehyde and melamine-formaldehyde resins, alkyd resins, phenoplasts, polycarbonates, polyolefins, such as polystyrene, polyvinylchloride, polyethylene, polypropylene, polyacrylonitrile, polyacrylic acid esters, rubber, casein, silicone, and silicone resins, individually or in admixture. The compounds of formula I are of particular interest, however, for the colouration of lacquers, paints and printing inks.

Some examples will now be given. Parts and percentages shows therein are by weight unless otherwise stated.

Example 1 216 Parts of 2-hydroxy 3-carboxy 1 -naphthaldehyde were dissolved in 20,000 parts of hot ethanol. To this solution were added 187 parts of 5-methyl 2-amino benzene sulphonic acid dissolved in 20,000 parts of boiling water. The whole was mantained on a steam bath for 15 minutes then cooled to room temperature and filtered. 200 Parts of copper acetate dissolved in 10,000 parts of water were then added to the solution with stirring and the stirring continued for a further 30 minutes. The precipitate of 370 parts of a yellow solid was then filtered off, washed thoroughly with water and then a little ethanol and dried in vacuo over silica gel.

The product had the formula:

Examples 2 to 7 By repeating the procedure of Example 1, but using the appropriate metal acetate, the products indicated in Table 1 were obtained, each of which contains 0 - 6 molecules of water.

TABLE 1 Example Product Colour

2 CQ; S0343 Red CH=NCH3. Mg2 Yellow OH CO2 OH 3 -CH= Ca2e Yellow \$- N-e CH3. Ca 2s Yellow CozO OH e O 5 \3e) 4 CH=NCH3.Mn2e Yellow CO2 OH CO2 OH CH=N- CH3.CO2 Yellow J CO20 OH 0 6 CH3 Ni2 9 Yellow CH=N CH3.Ni20 OH S030 7 H=N-- CH3 263 Yellow OH Examples 8- 11 The procedure of Example 1 was repeated, except that the 5-methyl-2-amino benzene sulphonic acid was replaced by 5-methyl-4-chloro-2-amino benzene sulphonic acid, and the appropriate metal acetate was used to produce the products shown in Table 2, each of which contains 0 - 6 molecules of water.

TABLE 2 Example Product Colour

8 n 503S Green 3 Yellow C OH CO2 OH sQe 9 CH=Nv CH3. my 2 (3 Red C02Gs OH C1 2&commat; Yellow CO2 > 503eR Red 10 5 Red X CH=NvCH3.Nl2(i3 Yellow eCH=NC% Atom CO2 OH 11 n 503e Red CH=Nv CH3.Zn 2&commat; Yellow CÓ CH3.Zn2&commat; Yellow CO2 OH Example 12 The procedure of Example 1 was repeated, except that the 5-methyl-2-amino benzene sulphonic acid was replaced by 5-chloro-4-methyl-2-amino benzene sulphonic acid and nickel acetate was used in place of copper acetate. The following product was obtained as a red yellow solid.

Examples 13 to 15 The procedure of Example 1 was repeated, except that the 5-methyl-2-amino benzene sulphonic acid was replaced by 2-amino-l-naphthalene sulphonic acid, and the copper acetate was replaced by the appropriate metal acetate to give the products shown in Table 3, each of which contains 0 - 6 molecules of water.

TABLE 3 Example Product Colour

13 O 503e Red CH=N Mg2e Yellow C02e OH 14 SQ s sL Yellow CH=N Mn CO2 OH OX ai Ni 26 Orange CO2 OH Example 16 PartA 216 Parts of 2-hydroxy 3-carboxy 1 -naphthaldehyde were dissolved in 10,000 parts of warm ethanol. To this solution was added 137 parts of anthranilic acid dissolved in 10,000 parts of ethanol. The mixture was heated on a steam bath for 15 minutes and on cooling to room temperature the product was filtered off, washed with ethanol and dried in vacuo.The orange solid had the formula:

Part B 335 Parts of the above product were mixed with 20,000 parts of ethanol and stirred at 60"C. 245 parts of manganese acetate dissolved in 5,000 parts of water were then added and the mixture was stirred at 60"C. for 3 hours. After cooling to room temperature the orange product was filtered off, washed thoroughly with hot water and hot ethanol and then dried in vacuo.

The product had the formula:

Example 17 The procedure of Example 16 was repeated, except that magnesium acetate was used instead of manganese acetate. The orange product had the formula:

Example 18 The procedure of Example 16 was repeated, except that the anthranilic acid was replaced by 5-methyl-2-amino benzoic acid. The orange product had the formula:

Example 19 216 Parts of 2-hydroxy 3-carboxy 1-naphthaldehyde were dissolved in 10,000 parts of warm ethanol. To this solution was added 137 parts of anthranilic acid dissolved in 10,000 parts of ethanol. The mixture was stirred at 600C. and 249 parts of nickel acetate in 5,000 parts of water were added dropwise.Stirring was continued at 600C. for a further 30 minutes and then after cooling to room temperature the yellow product was filtered off, washed with hot water and ethanol and dried in vacuo.

The product had the formula:

Example 20 216 Parts of 2-hydroxy 3-carboxy 1-naphthaldehyde were dissolved in 10,000 parts of ethanol and added to a solution of 276 parts of 5-nitro 2-amino benzoic acid (66% pure) in 10,000 parts of water. 245 Parts of manganese acetate in 5,000 parts of water were then added and the solution was heated on a steam bath for 6 hours, during which time a red solid was deposited front the solution. On cooling to room temperature the red product was filtered off, washed with water and ethanol and dried in vacuo.

The product had the formula;

Example 21 13.7 Parts of anthranilic acid were added to 200 parts of water containing 4.2 parts caustic soda and stirred.

17.1 Parts of 2-hydroxy-1-naphthaldehyde were added to form a deeply coloured solution. After 5 minutes 15.6 parts of sodium bisulphite were added and stirring was continued for a furtherfifteen minutes to produce a thick bright yellow suspension. This suspension was filtered and washed with 1,000 parts water then reslurrried in 200 parts water containing 20 parts sodium acetate and the whole stirred. 15.8 Parts of calcium acetate were dissolved in 200 parts water containing 66 parts of ammonium hydroxide (d = 0.88) and added over 20 minutes to the yellow slurry.The thick suspension was heated to 95"C. for 1 hour, filtered, washed and dried to yeild a bright yellow powder of the formula:

Examples 22-24 The procedure of Example 21 was repeated using the appropriate metal acetate to produce the products shown in Table 4, each of which contains 0 - 6 molecules of water.

TABLE 4 Example Product Colour

22 g9 C02'3 Green QCH=Nt NiZe Yellow C H N CO e 23 SCH=N C$9 Aln 7el Yellow or CH=N Mn2 24 Yellow 7 CH=N--C g2$ 0e Example 25 The procedure of Example 21 was repeated, except that the anthranilic acid was replaced by 5-methyl-2-amino benzoic acid and the calcium acetate was replaced by manganese acetate. The yellow product had the formula:

Example 26 The procedure of Example 21 was repeated, except that the anthranilic acid was replaced by 5-nitro-2-amino benzoic acid.The yellow product had the formula:

Example 27 The procedure of Example 26 was repeated, except that manganese acetate was used instead of calcium acetate. The yellow product had the formula:

Example 28 The procedure of Example 21 was repeated, except that the 2-hydroxy-1-naphthaldehyde was replaced by 2-hydroxy-3-carboxy-1 -naphthaldehyde. The yellow product had the formula:

Example 29 The procedure of Example 28 was repeated, except that manganese acetate was used in place of calcium acetate.The yellow product had the formula;

Example 30 60 Parts of the product of Example 4 were ball milled with 138 parts of a solution of an unmodified butylated melaminesformaldehyde resin in n-butanol and 452 parts ofxylol. 350 parts of a hydroxy acrylic resin, a 1:1 mixture of xylene and n-butanol, were added gradually and ball milling continued. The resulting mixture had a pigment to binder ration of 1 :5, this was adjusted to 1:10 by the addition of more resin solution and the paint was thinned to the required viscosity for spraying. Aluminium panels were sprayed and then stoved at 120sic. for 30 minutes. The resulting paint films had good fastness to light and heat.The resulting coated panels were a very attractive transparent yellow colour and could be oversprayed with, for example, a white paint of the same type without the yellow colour bleeding into and thus spoiling the new white finish.

When the stainer (with a 1:5 pigment to binder ratio) whose preparation is described above was combined with a suitable paste of finely powdered aluminium to give a pigment to aluminium ratio of 75:25 and the mixture was again thinned to a suitable viscosity for spraying, very attractive greenish yellow metallic coatings were obtained which also had good fastness properties.

In the same way by replacing the product of Example 2 with the products of any of the Examples 6,9, 10, 12, 14, 15, 16, 19,20,22,23,25, there could be obtained paint films having varying shades of yellow to orange. All were, however, characterised by having the same good fastness properties.

Example 31 1 Part of the product of Example 9 was mulled into 40 parts of a commercial letter press printing varnish.

The printing ink was used to produce prints in bright transparent yellow shades on paper and the resulting prints were found to have good fastness to light.

Claims (18)

1. An azomethine pigments of the general formula:

wherein A and B are the same or different and are aryl or heterocyclic radicals optionally substituted by non-water-solubilising groups, R represents hydrogen, an alkyl, cycloalkl, aryl or aralkyl radical, X is CO2, or S03, Y is hydrogen, CO2'l or CONHR' where R1 is hydrogen or an alkyl, aryl or heterocyclic radical, Lisa donor ligand containing oxygen or nitrogen, M is a divalent metal atom and xis 0 to 6.

2. An azomethine pigment as claimed in Claim 1, wherein A and/or B is an aryl radical having 6 to 14 carbon atoms.

3. An azomethine pigment as claimed in Claim 1 or 2, wherein A and'our B is a phenyl or naphthyl radical.

4. An azomethine pigment as claimed in any preceding claim which has the formula:

wherein R" is hydrogen or a non-water-solubilising group and B, R, X, M, Land x are as defined in Claim 1.

5. An azomethine pigment as claimed in any preceding claim which has the formula:

wherein R111 is hydrogen or a non-water-solubilising group, R, X, M, Land x are as defined in Claim 1 and R" is as defined in Claim 5.

6. An azomethine pigment as claimed in any preceding claim in which M is Mg, Ca, Mn, Fe, Co, Ni, Cu, Zn or Cd.

7. An azomethine pigment as claimed in any preceding claim, in which Lisa neutral donor containing oxygen.

8. An azomethine pigment as claimed in Claim 7, in which L is water, ethanol, tetrahydrofuran or dimethyl sulphoxide.

9. An azomethine pigment as claimed in any of Claims 1 to 6 in which L is ammonia or pyridine.

10. A process for producing an azomethine pigment as claimed in Claim 1, which comprises metallising the ligand of the formula:

wherein A, B, R and x are as defined in Claim 1.

11. A process as claimed in Claim 10, in which the metallisation is carried out using a solution or suspension of a salt or complex of metal M.

12. A process as claimed in Claim 11, in which the metallisation is carried out using the appropriate metal acetate.

13. A process as claimed in any of Claims 10 to 12, in which the metallisation is carried out at a temperature of up to 100 C. and at a pH of 8 - 9.

14. An azomethine pigment as claimed in Claim 1, substantially as hereinbefore described with reference to any one of the foregoing Examples.

15. A process as claimed in Claim 10, substantially as hereinbefore described with reference to any one of the foregoing Examples.

16. A method of colouring organic material which comprises incorporating therein a pigment as claimed in any one of Claims 1 to 9 and 14.

17. Organic material whenever coloured by a method as Claimed in Claim 16.

18. A method as claimed in Claim 16, substantially as hereinbefore described with reference to Example 30 or 31.