WO1995000592A1

WO1995000592A1 - Disazo dyes

Info

Publication number: WO1995000592A1
Application number: PCT/GB1994/001226
Authority: WO
Inventors: Peter Gregory; Ronald Wynford Kenyon
Original assignee: Zeneca Limited
Priority date: 1993-06-18
Filing date: 1994-06-06
Publication date: 1995-01-05

Abstract

Compounds of formula (1) and salts thereof, wherein: T?1 and T2¿ each independently is H, acyl or optionally substituted alkyl or aryl; or T?1 and T2¿ together represent an optionally substituted hydrocarbylene optionally interrupted by oxygen; D is optionally substituted phenylene or naphthylene; E is optionally substituted naphthylene or quinolinylene; Z is H or optionally substituted aryl; and n has a value of 0 or 1; provided that T1, T2 and Z are not all H when n has a value of 0 and their use in inks, especially ink jet printing inks, for paper.

Description

DISAZO DYES

This invention relates to chemical compounds and particularly to black dyes which are suitable for use in ink jet printing.

According to the present invention there is provided a compound of Formula (1) and salts thereof:

C Ό wherein: _τι and each independently is H, acyl or optionally substituted alkyl or aryl; or _τι and rrι2 together represent optionally substituted hydrocarbylene optionally interrupted by oxygen;

D is optionally substituted phenylene or naphthylene; E is optionally substituted naphthylene or quinolinylene; ZZ is H or optionally substituted aryl; and ft n has a value of 0 or 1; provided that T¹, T² and Z are not all H when n has a value of 0.

The optional substituents on any of the groups represented by T¹, T², D, E and Z are preferably selected from C_j.^-alkyl; especially methyl; ^-alkoxy, especially methoxy or ethoxy; optionally substituted aryl, especially optionally substituted phenyl or naphthyl; OH; CN; N0₂; halogen, especially chloro or bromo; acylamino, especially C_x_₄- lkyl-carbonyl-amino or benzoylamino; sulphonic acid (sulpho) ; phosphonic acid (phospho) ; boronic acid (boro) ; carboxylic acid (carboxy) ; amino, especially a group NT³T⁴ in which T³ and T⁴ each independently can be any of the groups represented by T¹ and T²; C₁.₄-alkoxycarbonyl and C₁_₄-alkylcarbonyl; unless stated otherwise.

When T¹ and T² together represent optionally substituted, optionally interrupted hydrocarbylene, they are preferably alkylene or alkyleneoxyalkylene containing 4 or 5 carbon atoms and oxygen atoms in the chain so that together with the N atom to which they are attached they form a 5- or 6-membered cyclcaliphatic group, especially piperidinyl or morpholinyl, either of which may be substituted as hereinbefore described.

When T¹ or T² is optionally substituted alkyl it is preferably optionally substituted C₁_₄-alkyl, such as ethyl, propyl or butyl, but especially methyl.

When T¹ or T² is or contains optionally substituted aryl, the other is preferably H or alkyl, especially C^-alkyl. When T¹, T² or Z is or contains aryl it is preferably optionally substituted phenyl, such as phenyl, 4-tolyl, 4- minophenyl, 4-methoxy-phenyl, 2-, 3- or 4-carboxyphenyl or 3,5-dicarboxyphenyl. When Z is optionally substituted phenyl, it is more preferably 3- or 4-carboxyphenyl or 3,5-dicarboxyphenyl.

When T¹ or T² is acyl, it is preferably optionally substituted alkyl-carbonyl or -sulphonyl or optionally substituted phenyl-sulphonyl or -carbonyl, the optional substituents being selected from any of those hereinbefore described. Especially preferred are C-^-alkylcarbonyl groups such as acetyl and propanoyl and phenylcarbonyl groups such as benzoyl.

D is preferably optionally substituted phen-1,3-ylene or phen-1,4-ylene, more preferably the latter, such as phen-1,4-ylene or 3-carboxyphen-1,4-ylene. E is preferably optionally substituted naphthylene especially optionally substituted naphth-1,4-ylene. Examples of suitable groups are naphth-1,4-ylene, 6-carboxynaphth-1,4-ylene, 7- carboxynaphth-1,4-ylene or mixtures thereof and 6-sulphonaphth-l,4- ylene, 7-sulphonaphth-l,4-ylene or mixtures thereof. When E is optionally substituted quinolinylene it is preferably optionally substituted quinolin-5,8-ylene.

The group T^N-D- in Formula (1) is preferably of Formula (3) or (4) , wherein T¹ and T² are as hereinbefore described and m is 0 or 1.

It is especially preferred that T^XT²N-D- is of Formula (3) wherein m is 0 or 1; T¹ and T² taken together with the N atom to which they are attached are piperidinyl or morpholinyl; or T¹ and T² each independently is H or optionally substituted alkyl.

A further feature of the present invention provides a dye of Formula (5) and salts thereof:

Formula (5) wherein:

R¹ is H, alkyl, substituted alkyl, aryl or substituted aryl;.

R² is H, alkyl or substituted alkyl; or

R¹ and R² together with the N atom to which they are attached represent piperidinyl or morpholinyl; m is 0 or 1 W is C-H, C-COOH or N; X is H, COOH or S0₃H; Y is H, COOH or S0₃H; z is H, aryl or substituted aryl; and n is 0 or 1; provided that (1) at least one of X and Y is H or COOH; and

(2) W is C-H or N when X and Y are both COOH. Nucleus A may be phenyl or naphthyl, preferably the former and, where it is naphthyl, the substituents shown may be on either benzene ring. Where Nucleus A is phenyl, the group -NR-'-R² is preferably in the ortho (2-) or para (4-) position with respect to the azo group, more preferably the latter, and when, as preferred, m is 1, the COOH group is preferably in the meta (3- or 5-) position with respect to the azo group.

Where R¹ or R² is alkyl this is preferably C--g-alkyl and more especially C-^-alkyl, such as methyl, ethyl, n-propyl, i-propyl, n-butyl or t-butyl. Where R¹ or R² is aryl this is preferably phenyl or naphthyl and especially the former. Where R¹ or R² is substituted, the substituents are preferably selected from those described above for T¹, T², D, E and Z. Examples of substituted groups represented by R¹, R², T¹, T² and Z include 2- and 4-tolyl, benzyl, methoxymethyl, methoxy-ethyl, ethoxyethyl, 2- and 4-anisyl, hydroxymethyl, hydroxyethyl, 4-hydroxypheny1, 4-cyanophenyl, 4-chlorophenyl and 3- acetylaminophenyl.

In Nucleus B, it is preferred that W is C-H, C-COOH or N, especially C-H. It is also preferred that one of X and Y is COOH or S0₃H, especially COOH and the other is H or that X and Y are both H.

In compounds of Formula (1) and (5) it is preferred that Z is H, phenyl or substituted phenyl, especially the last. Suitable substituents include those mentioned above, preferably COOH and especially where this is in the meta (3-) or para (4-) position on the phenyl ring. It is also preferred that n is 0.

In the compound Formula (5) it is preferred that there are at least two carboxy groups and that the number of carboxy groups is equal to or greater than the number of sulpho groups.

Components from which Nucleus A may be derived include 2,3-diaminobenzoic acid, 1,4-phenylenediamine; 2,5-diaminobenzoic acid, 1,5-diamino-6-carboxynaphthalεne, 1,5-diamino-7- carboxynaphthalene and 1,5-diaminonaphthalene; or from analogues in which one of the amino groups is replaced by a nitro group from which the second amine may be derived, either before or after preparation of a compound of Formula (1) or Formula (5) , by reduction. Other components from which Nucleus A may be derived are shown in the Examples.

Components from which Nucleus B may be derived include 1-naphthylamine, 1,6-Cleves acid, 1,7-Cleves acid, mixed Cleves acids, 8-amino-2-naphthoic acid, 5-amino-2-naphthoic acid and a mixture of 5-amino- and 8-amino-2-naphthoic acids. If such mixed components are employed the product will be a mixture of dyes containing different isomeric Nuclei B. Such mixtures can be made directly from mixed Cleves acids or from a mixture of 5-amino-2-naphthoic acid and 8- amino-2-naphthoic acid, respectively, without the need to separate the isomers.

Components from which Nucleus C may be derived include Gamma acid, 2R acid, N-phenyl-Gamma acid and N- (4-carboxyphenyl) -Gamma acid.

Examples of dyes of Formula (5) are shown in Table 1, wherein C-P means carboxyphenyl and a-C-P means dicarboxyphenyl:

Table 1

Dye NR^XR² (COOH)m W X Y Z n

1 4-NH₂ 3 -COOH C-H H COOH H 0

2 4-NH₂ 3 -COOH C-H COOH H H 0

3 4-NH₂ 3 -COOH C-H H H H 0

4 4-NH₂ 3 -COOH C-H H SO₃H 4-C-P 0

5 4-NH- m=0 C-H COOH COOH H 0

6 4-NH₂ 3 -COOH C-H S0₃H H 4-C-P 0

7 4-NH₂ 3 -COOH N H H 2-C-P 0

8 4-NH₂ 3 -COOH C-COOH H H 4-C-P 1

9 4-NH₂ 3 -COOH C-COOH H H phenyl 0

10 4-NH₂ 3 -COOH C-H H H 3,5-d-C-P 0

The compounds of Formula (1) and (5) can be made by analogous processes to those described in EP 356080. For example a compound of Formula (6) :

T^N-D-NH, (6) may be diazotised, e.g. in water at 0-5°C using NaN0₂, coupled onto an amine of formula H-E-NH₂ to give a monoazo compound. The monoazo compound may then be diazotised in a similar manner and coupled onto a suitable l-hydroxy-3-sulphonaphthalene having an -NHZ substituent at the 7-position and optionally a sul ho group at the 6-position; wherein E and Z are as hereinbefore defined. In the compound of Formula (6) the -NT^-T² may be in a protected form, e.g. in the form of a nitro or acetamido group. Suitable processes are substantially as described in the Examples.

The compound of Formula (1) or (5) is preferably in the form of a salt, especially a salt with an alkali metal cation or optionally substituted ammonium cation or a mixture of such cations, especially an ammonium, a substituted ammonium or a mixed alkali metal and ammonium salt.

The substituted ammonium cation may be a quaternary ammonium cation of the formula ⁺NQ₄ in which each Q independently is an organic radical, or two or three Qs together with the nitrogen atom to which they are attached form a heterocyclic ring and all remaining Qs are selected from C-.-₄-alkyl. Preferred organic radicals represented by Q are C-^-alkyl, especially methyl. Preferred heterocyclic rings formed by NQ₄ are 5 or 6 membered heterocyclic rings.

Examples of quaternary ammonium groups of formula ⁺NQ₄ are N⁺(CH₃)₄, N⁺(CH₂CH₃)₄, N-methylpyridinium, N,N-dimethyl piperidinium and N,N-dimethylmorpholinium. Alternatively the substituted ammonium cation may be of the formula ⁺NHT₃ wherein each T independently is H, C_j^-alkyl or hydroxy-Ci-₄-alkyl provided at least one T is C^-alkyl, or two or three groups represented by T together with the nitrogen atom to which they are attached form a 5 or 6 membered ring, especially a pyridine, piperidine or morpholine ring. It is preferred that the substituted ammonium cation is derived from an amine which is volatile under ambient conditions, i.e. at 20°C and atmospheric pressure.

Examples of groups of formula ⁺NHT₃ are (CH₃)₃N⁺H, (CH₃)₂N⁺H₂, H₂N⁺(CH₃) (CH₂CH₃) , CH₃N⁺H₃, CH₃CH₂N⁺H₃, H₂N⁺(CH₂CH₃)₂, CH₃CH₂CH₂N⁺H₃, (CH₃)₂CHN⁺H₃, pyridinium, piperidinium and morpholinium.

It is especially preferred that a compound of Formula (1) and (5) is in the form of the ammonium salt or the mono- or di- methylammonium salt.

The compounds can be converted into their ammonium salt form by dissolving an alkali metal salt thereof in water, acidifying with a mineral acid, adjusting the solution to pH 9-9.5 with ammonia or the appropriate amine and removing alkali metal salt by dialysis. The compounds of Formula (1) and (5) are notable for their strong, neutral, black shade, fastness to water and light, good solubility in water and mixtures thereof with water-miscible organic solvents and low tendency to bronze when printed on paper. Some compounds of the invention are better than others in these respects. Especially preferred dyes of Formula (1) are Dyes 1 to 4 shown in Table 1 above.

The compounds are especially useful for the preparation of inks, especially aqueous inks, used in ink jet printing and particularly thermal ink jet printing.

The water-fastness of the compounds on paper is generally increased if it is printed from an aqueous medium in the form of an ammonium or substituted ammonium salt.

According to a further feature of the present invention there is provided an ink comprising a compound of the present invention and a liquid medium. It is preferred that the compound is 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 based on the total weight of the ink.

The liquid medium is preferably water or a mixture comprising water and one or more water-soluble organic liquid, the water and organic liquid(s) preferably being in a weight ratio from 99:1 to 50:50 and more preferably 95:5 to 60:40 and especially 95:5 to 80:20.

The water-soluble organic liquid is preferably a _x-.₄- alkanol such as methanol, ethanol, n-propanol, isopropanol, n-butanol, s-butanol t-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; an oligo- or poly-C₂.₆-alkylene glycol such as diethylene glycol, triethylene glycol, poly(ethyleneglycol) or poly(propyleneglycol) of molecular weight up to 500; an alkylene glycol or thioglycol containing a C₂.₆-alkylene group such as ethylene glycol, propylene glycol, butylene glycol 1,4-pentylenediol or hexylene glycol; a thiodiglycol; a polyol such as glycerol or 1,2,6-hexanetriol; a C₁-₄-alkyl ether of a C₂.₄-alkylene glycol or oligo-C₂.₄-alkylene glycol 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 2- [2-butoxy-ethoxy]ethanol; a heterocyclic ketone or sulphone, such as 2-pyrrolidone, N-methyl-2- pyrrolidone or sulpholane; or a mixture containing two or more of the aforementioned water-soluble organic solvents.

Preferred water-soluble organic solvents are selected from 2-pyrrolidone, N-methylpyrrolidone, sulpholane, C₂.₆-alkylene glycols and Ci-₄-alkyl ethers of polyhydric alcohols, such as ethylene glycol, diethylene glycol, triethylene glycol or 2-methoxy-2-ethoxy-2-ethoxy ethanol; and a polyethylene glycol with a molecular weight of up to 500. A preferred specific solvent mixture is a binary or tertiary mixture of water and diethylene glycol; water and 2-pyrrolidone; water, ethylene glycol and 2-pyrrolidone; or water, ethylene glycol and N-methylpyrrolidone in weight ratios as herein described.

The water soluble organic solvent generally promotes the solubility of the dye in the aqueous medium and also the penetration of the dye into the substrate during printing. The addition of surfactants and/or biocides is also beneficial. Examples of other suitable liquid media are given in

US 4,963,189, US 4,703,113, US 4,626,284 and EP 4,251,50A.

It is preferred that the inks of the present invention comprise one or more penetrants, such as the water-soluble organic solvents hereinbefore described, to assist permeation of the dye into a paper substrate, a kogation-reducing agent to prevent or reduce the build-up of residue (koga) on the resistor surface in thermal ink jet printers and a buffer such as sodium borate, to stabilise the pH of the ink.

The kogation-reducing agent is preferably an oxo anion, such as described in EP 425150A. The oxo-anion may be C₂0₄ ^2", S0₃ ^2", S0₄ ²", molybdate, or As0₄ ^3" but is preferably a phosphate ester, or diorganophosphate or more especially a phosphate salt such as a dibasic phosphate (HP0₄ ²") , a monobasic phosphate (H₂P0₄ ^") or a polyphosphate (P₂0₇ ⁴J . The selection of counter ion is not believed to be critical and suitable examples include alkali metals, ammonium and alkylammonium cations. The kogation-reducing agent is preferably present in the ink at a concentration from 0.001% to 15% by weight of oxo-anion based on the total ink, and more preferably from 0.01% to 1%.

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 a dye for Formula (1) .

A suitable process for the application of an ink as herein- before defined comprises forming the ink into small droplets by ejection from a reservoir through a small orifice so that the droplets of ink are directed at a substrate. This process is commonly referred to as ink jet printing, and the ink jet printing processes for the present inks may be piezoelectric ink jet printing or thermal ink jet printing. In thermal ink jet printing, programmed pulses of heat are applied to the ink by means of a resistor, adjacent to the orifice during relative movement between the substrate and the reservoir.

A preferred substrate is an overhead projector slide or a cellulosic substrate, especially plain paper, which may have an acid, alkaline or neutral character. Textile materials such as cotton, viscose, jute, hemp, flax, nylon etc may also be printed with the compounds if so desired, for example using the methods described in EP 0550872 Al, Claims 1 to 9.

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

According to a still further aspect of the present invention there is provided a paper or an overhead projector slide printed with a dye of Formula (1) .

It has been found that further useful effects can be obtained if the dye or inks derived therefrom, as hereinbefore described, also contain a further dye or dyes of the type disclosed for ink jet printing in EP 468647; EP 468648; EP 468649 and EP

933000143. These dyes, especially the yellow dyes of EP 468647 and the cyan dyes of EP 93300014.3, can assist in the suppression of bronzing and can be used either alone or in combination. The present dye may be used in admixture with up to about 20% by weight of such dyes but more preferably from 2% to 10%, based on the weight of the resulting composition. 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 the dve of Formula

(a) Monoazo Stage

5-Amino-2-nitrobenzoic acid (18.2g) was added to a mixture of water (500ml) and concentrated hydrochloric acid (30ml) . It was cooled to 0-10°C and sodium nitrite (6.9g) added over 10 minutes. The mixture was stirred at 0-10°C for 2 hours and excess nitrite removed by addition of a little sulphamic acid.

7-Sulpho-l-naphthylamine (22.3g) was dissolved in water (500ml) at pH 8. The solution was added to the above diazo solution at 0-10°C and stirred for 18 hours. The product of Formula (8) was filtered off, washed with saturated sodium chloride solution and dried at 60°C. (b) Disazo Stage

The product of the Monoazo Stage (41.6g) was dissolved in water (500ml) at pH 8. Sodium nitrite (6.9g) was added and the solution added to a stirred mixture of ice water (200g) and concentrated hydrochloric acid (30ml) . It was stirred at 0-10°C for 2 hours and excess nitrite removed by addition of a little sulphamic acid.

4-Carboxyphenyl-Gamma acid (35.9g) was dissolved in water (500ml) at pH 8 and the solution added to the above diazo solution at 0-10°C. The pH was adjusted to 7-8 and the mixture stirred for 18 hours. The pH was then lowered to 4 by addition of 2N-hydrochloric acid and the product salted out by addition of 10% sodium chloride. It was filtered off.

It was purified by redissolving in water (1 litre) , warming to 80°C and salting to 10% with sodium chloride. The product of Formula (9) was filtered hot, washed with 10% sodium chloride solution and dried at 60°C. (c) Reduction Stage

The product of the Disazo Stage (5.9g) was dissolved in water (200ml) and a solution of sodium sulphide (3.0g) and sodium sulphite (0.2g) in water (20ml) added dropwise over 10 minutes. The mixture was stirred for 3 hours and salted to 20% with sodium chloride and the pH adjusted to 4. The product of Formula (7) was filtered off, washed with saturated sodium chloride solution and pulled dry.

The product was converted to the ammonium salt by acidification to pH 1 with HCl, filtered off, reslurried in water and the slurry adjusted to pH 11 with ammonia. The solution was then dialysed to remove sodium chloride, screened and the water evaporated to give dry colorant as ammonium salt. This was made into an ink (2% dye as ammonium salt) in water/diethylene glycol (92.5/7.5 parts) . When printed onto plain paper using a thermal ink jet printer, the ink gave an image with an intense neutral black shade having high water fastness and good light fastness.

Examples of other specific liquid media which can be used to prepare inks containing the dye disclosed in Example 1 and other dyes within the scope of the present invention are:

Water (60) ; Ethylene glycol (40)

Water (85) ; Diethylene glycol (15)

Water (90) ; Diethylene glycol (10)

Water (65) ; Glycerol (25) ; Triethanolamine (10)

Water (80); Ethylene glycol (15); Polyethylene glycol, MW 200 (5)

Water (80) ; Ethylene glycol (15) ; N-Methylpyrrolidone (5)

Water (80) ; Ethylene glycol (15) ; 2-Pyrrolidone (5)

Water (90) ; 2-Pyrrolidone (10)

Example 2

Preparation of the dve of Formula (3)

C

(a) Monoazo Stage

In place of the 18.2g of 5-amino-2-nitrobenzene acid used in Example 1 there was used 20.5g of 5-amino-2-diethylaminobenzoic acid. (b) Disazo Stage

The product from the monoazo stage (4.4g) was dissolved in water (50ml) at pH 8. Sodium nitrite (0.69g) was added and the solution added to a stirred mixture of ice water (20g) and concentrated hydrochloric acid (3ml) . It was stirred at 0-10°C for 2 hours and excess nitrite removed by addition of a little sulphamic acid.

4-Carboxyphenyl-gamma acid (3.6g) was dissolved in water (50ml) at pH 8 and the solution added to the above diazo solution at 0-10°C. The pH was adjusted to 7-8 and the mixture stirred for 18 hours. The pH was then lowered to 4 by addition of 2N hydrochloric acid and the product filtered off and washed with (a) 10% sodium chloride solution and then (b) acetone.

The product was converted to the ammonium salt by stirring in water (200ml) and adjusting the pH to 9-9.5 with concentrated ammonium hydroxide. The solution was added to water (100ml) and concentrated hydrochloric acid (30ml) , filtered, reslurried in water and the slurry adjusted to pH 9.5 with ammonia. The solution was dialysed to removed chloride ion, screened, evaporated and dried.

When made into an ink (2% dye as ammonium salt in water/2- pyrrolidone; 92.5/7.5) and printed onto plain paper using a thermal ink jet printer, it gave strong black shades having high water fastness and good light fastness.

Example 3

Preparation of the dve of Formula (4 )

C 4D (a)

In place of the 20.5g of 5-amino-2-diethylaminobenzoic acid used in Example 2 there was used 26.4g of 5-amino-2-di-n- butylamino-benzoic acid, (b) Disazo Stage

In place of the 4.4g of the monoazo stage used in Example 2 there was used 5.Og of the above monoazo stage.

The ammonium salt of the product was made into an ink (2% in water/diethylene glycol; 92.5/7.5) and printed onto plain paper using a thermal ink jet printer. It gave neutral black shades having high water-fastness and good light fastness.

Example 4 Preparation of the dye of Formula (5)

(a) Monoazo stage

5-Amino-2-diethylaminobenzoic acid (20.5g) was added to a mixture of water (500ml) and concentrated hydrochloric acid (30ml) . It was cooled to 0-10°C and sodium nitrite (6.9g) added over 10 minutes. The mixture was stirred at 0-10°C for 2 hours and excess nitrite removed by addition of a little sulphamic acid.

1-Naphthylamine (14.3g) was dissolved in ethanol (130ml) and added to the above diazo at 0-10°C. The pH was adjusted to 4-5 by addition of sodium acetate and the mixture stirred for 18 hours. The product was filtered off, washed with 10% sodium chloride solution and dried.

(b) Disazo stage

In place of the 4.4g of the monoazo stage used in Example 2 there was used 3.6g of the above monoazo stage.

The ammonium salt of the product was made into an ink (2% in water/diethylene glycol; 92.5/7.5) and printed onto plain paper using a thermal ink jet printer. It gave neutral black shades having very high water fastness and good light fastness.

Example 5

Preparation of the dve of Formula (6)

C 6D

(a) Monoazo stage

5-Amino-2-anilinobenzoic acid (22.8g) was added to water (150ml) and the pH adjusted to 8-9. Sodium nitrite (6.9g) was added and the mixture added to a mixture of water (285g) and concentrated hydrochloric acid (50ml) . It was stirred for 2 hours at 0-10°C and excess nitrite removed with a little sulphamic acid.

7-Sulpho-l-naphthylamine (22.3g) was dissolved in water (500ml) at pH 8. The solution was added to the above diazo solution at 0-10°C and stirred for 18 hours. The pH was adjusted to 5 with concentrated hydrochloric acid and the product filtered off, washed with saturated sodium chloride solution and dried at 60°C. (b) Disazo stage

In place of the 4.4g of the monoazo stage used in Example 2 there was used 4.6g of the above monoazo stage.

The ammonium salt of the product was made into an ink (2% in water/diethylene glycol; 92.5/7.5) and printed onto plain paper using a thermal ink jet printer. It gave strong black shades having high water fastness and good light fastness.

Example 6

Preparation of the dyes of Formula (7)

(7)

wherein R=H and R =CH₃CO- ( a ) Monoazo stage

2-Acetylamino-5-aminobenzoic acid (11.Og) was added to water (500ml) and the pH adjusted to 8.0 by addition of 2N sodium hydroxide solution. Sodium nitrite (4.0g) was added and the solution then added to a mixture of ice water (100ml) and concentrated hydrochloric acid (20ml) over 5 minutes at 0-10°C. The mixture was stirred for 1 hour at 0-10°C and excess nitrous acid removed by addition of a little sulphamic acid.

1-Naphthylamine (8.0g) was dissolved in ethanol (300ml) and the solution added to the above diazo. The pH was adjusted to 4.0 by addition of 2N sodium hydroxide solution and the mixture stirred for 18 hours. The precipitated product was filtered off, washed with 10% sodium chloride solution and dried, (b) Disazo Dve (R=CH₃C0-)

HCOCH,

CH

The dried product from Stage (a) (9.25g) was dissolved in water (900ml) by addition of 2N sodium hydroxide solution to pH 10. Sodium nitrite (2.0g) was added and the solution then added to a mixture of ice water (75g) and concentrated hydrochloric acid (10ml) at 0-10°C. It was stirred at 0-10°C for 4 hours and the excess nitrite removed by addition of a little sulphamic acid.

Acetyl-gamma acid (15g) was dissolved in water (200ml) and the solution added to the above diazo suspension at 0-10°C. The pH was adjusted to 7.5 and the mixture stirred for 18 hours. The product was filtered off, washed with acetone and dried. (c) Disazo Dve (R=H)

The dried disazo dye from Stage (b) (6.7g) was added to a mixture of ethanol (100ml) and 2N sodium hydroxide solution (200ml) . The mixture was stirred and heated under reflux for 3 hours. The product was isolated by addition of concentrated hydrochloric acid to pH 7 and the precipitated product filtered off and washed with a little 10% sodium chloride solution.

The dyes produced in Stages (b) and (c) were both converted to the ammonium salt as in Example 1 and then dialysed and screened. When made into an ink (2% in water/diethylene glycol; 92.5/7.5) and printed onto plain paper using a thermal ink jet printer they gave prints with intense black shades, very high water fastness and good light fastness. Example 7

Preparation of the dye of Formula (8)

Where R=H and R=CH₃C0-. (a) Monoazo stage

CHgCON

In place of the 14.3g of 1-naphthylamine used in Stage (a) of Example 6 there was used 19.Og of an approximately 50:50 mixture of 5-amino-2-naphthoic acid and 8-amino-2-naphthoic acid, (b) Disazo Dve (R=CH₃CO-)

In place of the 9.25g of monoazo stage used in Stage (b) of Example 6 there was used 9.8g of the above monoazo stage, (c) Disazo Dve (R=H)

The hydrolysis as described in Stage (c) of Example 6 was performed on the disazo dye of Stage (b) of this Example.

The dyes produced in Stages (b) and (c) were both converted to their ammonium salts as in Example 1 and then dialysed and screened. When made into an ink (2% in water/diethylene glycol; 92.5/7.5) and printed onto plain paper using a thermal ink jet printer both dyes gave prints with intense black shades, good water fastness and good light fastness.

Example 8

Preparation of the dve of Formula (9)

C9

(a) Monoazo stage

In place of the 11.Og of 2-acetylamino-5-aminobenzoic acid used in Stage (a) of Example 6 there was used 13.3g of 5-amino-2-3' - methylpiperidyl-benzoic acid, (b) Disazo stage

In place of the 4.4g of the monoazo stage used in Example 2 there was used 3.9g of the above monoazo stage.

The ammonium salt of the product was made into an ink (2% in water/diethylene glycol (92.5/7.5) and printed onto plain paper using a thermal ink jet printer. It gave strong neutral black shades having high water fastness and good light fastness. Example 9

Preparation of the dve of Formula ( 10)

C 0D

(a) Monoazo Stage

The procedure of Example 8, Stage (a) was repeated using 11.Og of 2- (2-aminoethylamino) -5-aminobenzoic acid in place of the 13.3g of 5-amino-2- (3-methylpiperidyl) -benzoic acid used in Stage (a) of Example 8. (b) Disazo Stage

The procedure of Example 8, Stage (b) was repeated using 4.3g of the dried product from Stage (a) of this Example in place of the 3.9g of the dried product from Stage (a) of Example 8.

The dye produced in Stage (b) was converted to the ammonium salt as in Example 1 and then dialysed and screened. When made into an ink (2% in 92.5/7.5 water/diethylene glycol) and printed onto plain paper using a thermal ink jet printer, it gave a print with an intense black shade, very high water fastness and good light fastness.

Claims

1. A compound of Formula (1) and salts thereof:

C O wherein:

T¹ and T² each independently is H, acyl or optionally substituted alkyl or aryl; or T¹ and T² together represent an optionally substituted hydrocarbylene optionally interrupted by oxygen;

D is optionally substituted phenylene or naphthylene;

E is optionally substituted naphthylene or quinolinylene;

Z is H or optionally substituted aryl; and n has a value of 0 or 1; provided that T¹, T² and Z are not all H when n has a value of 0.

2. A dye of Formula (5) and salts thereof:

Formula (5) wherein:

R¹ is H, alkyl, substituted alkyl, aryl or substituted aryl; R² is H, alkyl or substituted alkyl; or R¹ and R² taken together with the N atom to which they are attached form an optionally substituted heterocyclic ring, preferably a 5- or 6-membered ring; m is 0 or 1 W is C-H, C-COOH or N;

X is H, COOH or S0₃H; Y is H, COOH or S0₃H; Z is H, aryl or substituted aryl; and n is 0 or 1; provided that (1) at least one of X and Y is H or COOH; and

(2) W is C-H or N when X and Y are both COOH.

3. An ink comprising a solution of a compound according to Claim 1 or Claim 2 in a liquid medium.

4. A process for printing a substrate with an ink according to Claim 3 using an ink jet printer.

5. A substrate comprising paper or an overhead projector slide printed with a dye according to Claim 1 or Claim 2.