GB2251625A

GB2251625A - Disazo compounds

Info

Publication number: GB2251625A
Application number: GB9127336A
Authority: GB
Inventors: Peter Gregory; Prahalad Manibhai Mistry
Original assignee: Imperial Chemical Industries Ltd
Current assignee: Imperial Chemical Industries Ltd
Priority date: 1991-01-11
Filing date: 1991-12-24
Publication date: 1992-07-15
Also published as: GB9127336D0; GB9100652D0

Abstract

A compound which, in the free acid form, is of Formula (1a): <IMAGE> wherein W and X are each independently selected from H, COOH, @@ SO3H, halo, hydroxy, nitro, cyano, @@@@ C1-6-alkyl, C1-6-alkoxy and @@@@ C1-7-acylamino; Y is H, COOH or SO3H; V is H or SO3H; R and R<1> are each independently H or C1-6-alkyl substituted by 0, 1 or 2 -COOR<2> groups; and R<2> is H or C1-6-alkyl; provided that at least one of W, X and Y is COOH. The compound is useful as a black dye in ink jet printing.

Description

COMPOUND This invention relates to a disazo compound and inks produced therefrom, and in particular to a black disazo anionic dye which is suitable for the coloration of various substrates.

According to a first aspect of present invention there is provided a compound which, in the free acid form, is of Formula (la):

3 2 w OH 2 N=N 4B 1 N=N NRR1 4/ -;2N=N---( > .

4 /8 6 7 5 A Y V 6 7 B 7 X Formula (la) wherein W and X are each independently selected from H, COOH, SO3H, halo, hydroxy, nitro, cyano, C1~6-alkyl, C1~6 alkoxy and C 17-acylamino; Y rs H, COOH or SO3H; V is H or SO3H; R and R are each independently H or C1 6-alkyl substituted by 0, 1 or 2 -COOR groups; and R2 is H or C1 6-alkyl; provided that at least one of W, X and Y is COOH.

It is preferred that W is COOH and that X is selected from H; COOH; S03H; chloro; bromo; hydroxy; C14-alkyl, especially methyl; C1-4-alkoxy especially methoxy; and C1 4-alkylcarbonylamino, especially acetamido; and more especially, from H and COOH.

Where W is COOR and X is H, the COOH substituent represented by W may be in any position on the terminal naphthyl group but is preferably in the 1, 3, 6 or 7- position when the azo group is attached to the 2 position and in the 3, 4, 6 or 7- position when the azo group is attached to the 1 position.

Where W and X are both COOH, they are preferably in the 4, 5 or 6, 7 positions on the naphthyl group, especially when the azo group is attached to the 1 position.

Y is preferably at the 6- or 7- position of Ring B of Formula (1). It is preferred that Y is SO3H.

It is preferred that V is H.

R and R are preferably each independently H or C1-4-alkyl.

It is preferred that R2 is H, methyl or ethyl.

It is preferred that the compound of Formula (1) contains from two to four COOH groups. It is also preferred that the number of COOH groups is equal to or greater than the number of SO3H groups. It is also preferred that at least one, and more especially at least two, of the COOH groups are attached directly to naphthalene ring carbon atoms.

It is preferred that there are a maximum of two SO3H groups in the compound of Formula (la) or (lb), i.e. that only one of V, X and Y is SO3H.

A preferred compound according to the invention is, when in the free acid form, of Formula (lob):

OH / N-N N --( HNg 2 \ / \ HO3S 6 7 Y F 0 rmu I a ( i b ) XI wherein: X1 is SO 3H or COOH; and Y is H, COOH or S03H; provided that the compound contains at least one COOR group.

A composition containing two compounds of the invention is also useful as a colorant for inks used in ink jet printing.

Accordingly the present invention also provides a composition containing two compounds of the invention, preferably in a weight-to-weight ration of 95:5 to 5:95, more preferably 80:20 to 20:80, especially 40:60 to 60:40.

Examples of diazo components from which Ring A may be derived are 2-amino-3-carboxynaphthalene l-amino-8-carboxynaphthalene l-amino-6-carboxynaphthalene 1-amino-7-carboxynaphthalene 2-amino-6-carboxynaphthalene 2-amino-7-carboxynaphthalene l-amino-6,7-dicarboxynaphthalene l-amino-3-carboxynaphthalene 1-amino-4, 5-dicarboxynaphthalene l-aminonaphthalene l-amino-2-hydroxynaphthalene 2-amino-3-hydroxynaphthalene l-amino-4-hydroxynaphthalene l-amino-7-hydroxynaphthalene l-amino-4-cyanonaphthalene 2-amino-3-chloronaphthalene l-amino-4-nitronaphthalene l-amino-4-chloronaphthalene l-amino-4-bromonaphthalene l-amino-4-sulphonaphthalene l-amino-5-sulphonaphthalene l-amino-6-sulphonaphthalene l-amino-7-sulphonaphthalene l-amino-8-sulphonaphthalene 2-amino-1-sulphonaphthalene 2-amino-5-sulphonaphthalene 2-amino-6-sulphonaphthalene 2-amino-7-sulphonaphthalene 2-amino-8-sulphonaphthalene l-amino-2-hydroxy-6-nitro-4-sulphonaphthalene l-amino-2-hydroxy-4-sulphonaphthalene 1-amino-5-hydroxy-7-sulphonaphthalene 1-amino-8-hydroxy-4-sulphonaphthalene 2-amino-3-hydroxy-6-sulphonaphthalene 2-amino-5-hydroxy-7-sulphonaphthalene 2-amino-8-hydroxy-6-sulphonaphthalene 2-amino-8-hydroxy-6-carboxynaphthalene 2-amino-8-hydroxy-7-carboxynaphthalene l-amino-2-hydroxy-3-carboxynaphthalene 1-amino-4-hydroxy-3-carboxynaphthalene l-amino-7-hydroxy-6-carboxynaphthalene 2-amino-1-bromo-3-carboxynaphthalene 2-amino-1-nitro-3-carboxynaphthalene 2-amino-6-sulpho-3-carboxynaphthalene Examples of suitable couplers from which the central group B is derived are: 1-aminonaphthalene 1,6-Cleves acid 8-amino-2-naphthoic acid 1,7-Cleves acid 5-amino-2-naphthoic acid Mixture of 1,6- & 1,7-Cleves acids 5-amino-2,3-dicarboxynaphthalene Mixture of 8- and 5-amino-2-naphthoic acid Examples of suitable couplers from which the third group C is derived are: Gamma acid N-butyl-Gamma acid N-methyl-G mma acid N-carboxymethyl-Gamma acid N,N-dimethyl-Gamma acid N,N-di(carboxymethyl)-Gamma acid N,N-diethyl-Gamma acid N-(beta-carboxyethyl)-Gamma acid 2R acid N-butyl-2R acid N-methyl-2R acid N-carboxymethyl-2R acid N,N-dimethyl-2R acid N,N-di(carboxymethyl)-2R acid N,N-diethyl-2R acid N-(beta-carboxyethyl)-2R acid Examples of preferred compounds of Formula (1) are given in the following tables: : Table 1 - Azo group connected to 1-position of naphthalene Ring A X W Y R R R1 V 6/7 COOH H COOH H H H 6/7 COOH H COOH H H SO 3H 6/7 COOH H H H H H 4-COOH 5-COOH H H H H 4-COOH 5-COOH 6/7 COOH H H SO 3H 4-COOH 5-COOH H H H H 6/7 COOH H S03H H H H 4-COOH 5-COOH COOH H H SO 3H H 4-COOH COOH H H H 6/7 COOH H H CH2COOH CH3 SO 3H 6/7 COOH H H CH2COOH H SO 3H 6-COOH 7-COOH SO 3H CH2COOH H SO 3H 6/7 COOH H H C2H4COOH H H 6/7 COOH H H CH2COOH H SO 3H 4-COOH 5-COOH H CH2COOH H H 6-COOH 7-COOH H C2H4COOH 4 H H 4-COOH 5-COOH H CH2COOH H H H 3-COOH COOH H H H H 4-COOH H H H SO3H H 5-COOH H CH2COOH H H H 8-COOH H CH2COOH CH2COOH H Table 2 - Azo group connected to the.2-position of naphthalene Ring A X W Y R R R1 V 6-COOH 7-COOH H CH3 CH3 H 6-COOB 7-COOH H C2H5 C2H5 SO 3H 6-COOH 7-COOH H H H H 6-COOB 7-COOH H H C H H 4-OH 3-COOH H H H SO3H 6-OH 7-COOH H H H H 8-OH 6-COOH H H H H 1-BR 3-COOH H H H H 6-SO 3H 3-COOH COOH H H SO 3H 1-NO2 3-COOH H H H H In the form of salts, especially salts formed with an alkali metal, ammonia or an amine, which are a further feature of the present invention, the compounds of Formula (1) are very soluble in water, generally to the extent of 5% or more by weight at pH 7.5 and above, especially from pH 7.5 to 9.0.However, the water-solubility drops sharply below pH 7.5 and below pH 6 the compounds are virtually insoluble in water and aqueous media.

The present compounds can be converted into their salt with ammonia or an amine by dissolving the dye in the form of a salt with an alkali metal, acidifying with a mineral acid, adjusting the solution to pH 9-9.5 with ammonia or an amine and removing alkali metal chloride ions by dialysis.

The preferred amine salts of compounds of Formula (la) or (lb) are those formed with methyl, dimethyl and trimethylamine; ethyl, diethyl and triethylamine; and tri(hydroxyethyl)amine.

The present dyes can be made by diazotising a compound or mixture of compounds which in the free acid form is of Formula (2):

9 2 w 4 / \ 1 NH2 3 2 N=N 5 5 ? a 6 I- 7 X Formula ( 2) and coupling with a substituted naphthalene of Formula (3):

Formula (3) wherein W, X, Y, R, R1 and V are as hereinbefore defined.

It has been found that a compound of Formula (1) can be dissolved in an aqueous medium above pH 7.5, preferably from pH 7.5 to pH 9, at normal concentrations to form an ink which, depending on type of ink required can be up to 20% by weight, but is preferably from 1 to 5% by weight, so that it can be applied, by any suitable technique, especially ink-jet printing, to a paper substrate. After application of the ink to the substrate and evaporation of the solvent, the compound is at a pH determined by the surface of the paper substrate. The natural pH of many paper substrates is such that the compound will be be in an environment from pH 5 to 7. Because the water-solubility of the compound is much lower below pE 7 and virtually zero at pH 6, it will be more resistant to removal from the substrate by washing, i.e. it will have a high water-fastness.

We have found also that the water-fastness of the present compound on the paper is increased if they are printed from an aqueous medium in the form of an ammonium or substituted ammonium salt.

Examples of amines used to form such salts include methylamine, dimethylamine, trimethylamine, ethylamine, n-propylamine, iso-propylamine, n-butylamine, iso-butylamine, sec-butylamine, tert-butylamine, piperidine, pyridine, morpholine, allylamine, diethylamine, triethylamine and mixtures thereof. It is not essential that the compounds are completely in the form of the ammonium salt or substituted ammonium salt and mixed alkali metal and either ammonium salt or substituted ammonium salt are effective, especially those in which at least 50% of the cations are ammonium or substituted ammonium ions. It is particularly preferred that the compounds of Formula (la) or (lib) are in the form of their ammonium or mixed ammonium/alkali metal salt.

A suitable ink comprises a mixture of one or more compounds according to the first aspect of the present invention, especially two, and a liquid medium, preferably an aqueous medium, for example an ink analogous to those described in US patent specification 4,963,189. It is preferred that the compound or compounds are completely dissolved in the liquid medium to form a solution.

The ink preferably contains from 0.5% to 20%, more preferably from 0.5% to 15%, and especially from 1% to 5%, by weight of the compound or salt thereof based on the total weight of the ink.

The liquid medium is preferably water or a mixture comprising water and a water-soluble organic solvent, preferably respectively in a weight-to-weight ratio of 99:1 to 1:99, more preferably 95:1 to 50:50, especially 90:10 to 60:40.

The water-soluble organic solvent is preferably a C1-C4- alkanol such as methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butanol or isobutanol; an amide such as dimethylformamide or dimethylacetamide; a ketone or ketone alcohol such as acetone or diacetone alcohol; an ether such as tetrahydrofuran or dioxane; a polyalkylene glycol such as polyethylene glycol or polypropylene glycol; an alkylene glycol or thioglycol containing a C -C alkylene group such as ethylene glycol, propylene glycol, butylene 26 glycol or triethylene glycol; a thiodiglycol, hexylene glycol, or diethylene glycol; a polyol such as glycerol or 1,2,6-hexanetriol; a lower alkyl ether of a polyhydric alcohol such as 2-methoxyethanol, 2-(2-methoxyethoxy)ethanol, 2-(2-ethoxyethoxy)- ethanol, 2-[2-(2-methoxyethoxy)ethoxy]ethanol, 2-[2-(2-ethoxyethoxy)ethoxy]-ethanol or N-methylpyrrolidone; or a mixture containing two or more of the aforementioned water-soluble organic solvents.

The preferred water-soluble organic solvent is an alkylene glycol or lower alkyl ether of a polyhydric alcohol such as ethylene glycol, diethylene glycol, triethylene glycol or 2-methoxy-2-ethoxy2-ethoxyethanol; or a polyethylene glycol with a molecular weight of up to 500. A preferred specific solvent mixture is a binary mixture of water and diethylene glycol in a weight-to-weight ratio as mentioned above.

A further aspect of the present invention provides a process for printing a substrate with an ink using an ink jet printer, characterised in that the ink contains at least one compound according to the first aspect of the present invention.

A preferred process for the application of an ink as hereinbefore defined to a substrate, for example paper, comprises forming the ink into small droplets by ejection from a reservoir through a small orifice by the application of heat so that the droplets of ink are directed at the paper substrate. This printing process is referred to as thermal ink jet printing and is used to form a record on the paper substrate by the programmed application of pulses of heat to the ink adjacent to the orifice during relative movement between the substrate and the reservoir.

The preferred substrate is a cellulosic substrate, especially paper.

The preferred ink used in the process is as hereinbefore described.

According to a still further aspect of the present invention there is provided paper printed with a compound according to the invention.

The invention is further illustrated by the following Examples in which all parts and percentages are by weight unless otherwise indicated.

Example 1 Preparation of

Stage 1 A 1 to 1 mixture (by weight) of 6-carboxy-l-naphthylamine and 7-carboxy-L-naphthylamine (18.7g 0.1M) is stirred in water (200ml) at room temperature and 2N NaOH added to form a solution at pH 8.0. 2N NaNO2 solution (50ml) is added and the mixture stirred to homogenise.

The solution is added gradually to a mixture of ice/water (150ml) and 35% HCl (50ml) at 5 C and the resulting solution stirred for 2 hours at 50C. Sulphamic acid solution (10%) is added to destroy excess nitrous acid to give a first diazo suspension.

1,7-Cleves acid (22.39, 01.M) is dissolved in water (150ml) and 47% NaOH solution to form a solution at pH 8.5. The solution is cooled to 5oC. To this solution is added the above diazo suspension and the pH adjusted to 4-5 by the addition of sodium acetate. The mixture is stirred for 18 hours and the dye collected by filtration and washed with little brine solution.

Stage 2 The paste from Stage 1 (0.lM) is dissolved in water (1 litre) with addition of 2N NaOH solution, pH 10. 2N NaNO2 solution (50ml) is added and the mixture stirred for 3 minutes, then added gradually to a mixture of ice/water (150ml) and 36% HCl (50ml) at 5oC using rapid agitation. The resulting suspension is stirred for 2 hours at 50C.

Sulphamic acid (10%) is added in order to remove excess nitrous acid and give a second diazo suspension.

Gamma acid (22.49, 0.1M) is dissolved in water (500ml) with addition of 2N NaOH solution, pH 9.0. The solution is cooled to 0-10 C and added to the second diazo suspension, maintaining the pH at 8.0 with 2N NaOH solution.

The precipitated product is collected by filtration and washed with 5% NaCl solution (100ml) to give a paste.

Stage 3 The paste from Stage 2 is stirred in water (500ml) at pH 8.0 until a complete solution is obtained. The solution is then heated to 70-800C and 5% NH4Cl is added, followed by concentrated HCl to adjust the pH to 1.0. The precipitated dye is collected by filtration and washed with 1N HCl solution (500ml) to give a paste.

The paste is stirred in water (500ml) and concentrated ammonium hydroxide added to raise the pH to 9-9.5 to give a solution which is dialysed to remove chloride ions and solvent evaporated to give the title compound in the form of it's ammonium salt. When made into an ink and printed onto plain paper using a thermal ink jet printing machine, the printed image has a deep black shade.

Examples of specific inks including the title dye are: Ink Dye Content Liquid medium and other components (parts) (parts) 1 2.5 Water (60) Ethylene glycol (40) 2 4.0 Water (85) Diethylene glycol (15) 3 1.0 Water (90) Diethylene glycol (10) 4 3.0 Water (65) Glycerol (25) Triethanolamine (10) 5 2.0 Water (80) Ethylene glycol (15) Polyethylene glycol (MW 200) (5)

Claims

CLAIMS 1. A compound which, in the free acid form, is of Formula (la):

3 2 w OH 3 2 N=N X N=N < NRR t 4/ 1 B 8 41\NRR 1 5 H 0 3 S VHost 5 A 6 7 V 7 X Formula (la) wherein W and X are each independently selected from H, COOH, SO3H, halo, hydroxy, nitro, cyano, C1~6-alkyl, C16 alkoxy and C1-7 acylamino; Y is H, COOH or SO3Hi V is H or SO3H; R and R1 are each independently H or C1-6-alkyl substituted by 0, 1 or 2 -COOR groups; and R2 is H or C1 6-alkyl; provided that at least one of W, X and Y is COOH.
2. A compound according to Claim 1 wherein R and R are H.
3. A compound according to Claim 1 or Claim 2 wherein W is COOH.
4. A compound according to any one of the preceding claims wherein X is H.
5. A compound according to any one of the preceding claims wherein Y is S03H.
6. A compound which, in the free acid form, is of Formula (lb):

OH / N=N \ NNM$j)NH 2 2 / \ HO3S 6 7 Y F 0 rmu I a (1 b ) Xl wherein: X1 is SO3H or COOH; and Y is H, COOH or SO3H; provided that the compound contains at least one COOH group.
7. A compound according to Claim 1 in the form of its ammonium salt.
8. A composition containing two compounds according to Claim 1 or Claim 6.
9. An ink comprising a mixture of one or more compounds according to Claim 1 and a liquid medium.
10. A process for printing a substrate with an ink using an ink jet printer, characterised in that the ink contains at least one compound according to Claim 1.