WO2013064802A1

WO2013064802A1 - Azaphthalocyanines

Info

Publication number: WO2013064802A1
Application number: PCT/GB2012/052375
Authority: WO
Inventors: Clive Foster; Prakash Patel; Keiichi Tateishi; Yoshihiko Fujie
Original assignee: Fujifilm Imaging Colorants Limited
Priority date: 2011-10-31
Filing date: 2012-09-26
Publication date: 2013-05-10
Also published as: GB201118750D0; TW201321450A

Abstract

Azaphthalocyanine intermediates for use in the preparation of ink-jet dyes.

Description

AZAPHTH ALOCYAN I N ES

This invention relates to intermediates for use in the preparation of ink-jet dyes and to ink-jet dyes prepared from these intermediates.

Ink jet printing is a non-impact printing technique in which droplets of ink are ejected through a fine nozzle onto a substrate without bringing the nozzle into contact with the substrate. The set of inks used in this technique typically comprise yellow, magenta, cyan and black inks.

With the advent of high-resolution digital cameras it is becoming increasingly common for consumers to print photographs using an ink jet printer. This avoids the expense and inconvenience of conventional silver halide photography.

While ink jet printers have many advantages over other forms of printing and image development there are still technical challenges to be addressed. For example, there are the contradictory requirements of providing ink colorants that are soluble in the ink medium and yet display excellent wet-fastness (i.e. prints that do not run or smudge when printed). The inks also need to dry quickly to avoid printed sheets sticking together, but they should not form a crust over the tiny nozzle used in the printer. Storage stability is also important to avoid particle formation that could block the printer nozzles especially since consumers can keep an ink jet ink cartridge for several months. Furthermore, and especially important with photographic quality reproductions, the resultant images should not bronze or fade rapidly on exposure to light or common oxidising gases such as ozone. It is also important that the shade and chroma of the colorant are exactly right so that any image may be optimally reproduced.

Thus developing new colorants for ink jet printing presents a unique challenge in balancing all these conflicting and demanding properties.

Historically phthalocyanines have been the only cyan dyes able to meet these demanding criteria. However recently a new class of phthalocyanine analogues, the azaphthalocyanines, have begun to show considerable promise.

The present inventors have found that by carefully controlling the structure of an azaphthalocyanine ring from which sulfonamide dyes can be produced it is possible to further optimise their performance.

The present invention provides a process for preparing a copper azaphthalocyanine and salts thereof which comprises cyclising a compound of Formula (1 ) with a compound of Formula (2) and a compound of Formula (3):

Formula (1 ) Formula (2) Formula (3);

wherein:

R¹ and R² are cyano, carboxy, carboxamide or together form a group of formula:

in the presence of a suitable copper salt and a nitrogen source (if required).

Preferably R¹ and R² are cyano or carboxy, especially carboxy. More preferably R¹ and R² are the same. It is especially preferred that R¹ and R² are both carboxy.

The cyclisation reaction is preferably carried out in any suitable liquid medium.

When R¹ and R² are carboxy preferred liquid media include kerosene, 1 ,2- dichlorobenzene, ethylene glycol, diethylene glycol and sulfolane, preferably the liquid medium comprises sulfolane. The reaction may also be carried out in the absence of solvent, for example in molten urea.

When a compound of Formula (1 ) is cyclised with a compound of Formula (2) and a compound of Formula (3) the preferred molar ratio of the compound of Formula (1 ) to the compound of Formula (2) and the compound of Formula (3) is in the range of from 10:1 :1 to 1 :10:1 to 1 :1 :10. More preferably the molar ratio of the compound of Formula (1 ) to the compound of Formula (2) and the compound of Formula (3) is in the range of from 2:1 :1 to 1 :2:1 to 1 :1 :2. It is especially preferred that the molar ratio of the compound of Formula (1 ) to the compound of Formula (2) and the compound of Formula (3) is in the range of from 0.6:2.4:1 to 1 :2:1 . More especially the molar ratio of the compound of Formula (1 ) to the compound of Formula (2) and the compound of Formula (3) is in the range of from 0.7:2.3:1 to 0.8:2.2:1 .

In one preferred embodiment of the process a copper azaphthalocyanine and salts thereof is prepared by cyclising compounds of Formula (1 ) in the range of from 0.5 to 3 molar equivalents with compounds of Formula (2) in the range of from 1 to 3 molar equivalents and compounds of Formula (3) in the range of from 0.5 to 1 .5 molar equivalents. When R¹ and R² are carboxy the cyclisation reaction is preferably perfornned at a temperature in the range of from 80 to 250 " C, more preferably 150 to 250 ^° C and especially of from 170 to 200 ^° C.

When R¹ and R² are cyano lower temperatures may be used.

Preferably the cyclisation reaction of stage (a) is performed in the range of from 1 to 20 hours, more preferably 2 to 20 hours and especially 4 to 16 hours

The length of time for which the cyclisation reaction of stage (a) is performed depends on the temperature used. For example higher temperatures require less time and lower temperatures require more time.

In a preferred embodiment the process is performed at a temperature in the range of from 170 to 200 ^° C for a time in the range of from 4 to 16 hours.

In the process of the present invention, depending on the reactants and reaction conditions, it may be advantageous to incorporate a base in the cyclisation reaction. Any suitable base may be used. Preferably the base is 1 ,8- diazabicyclo[5.4.0]undec-7-ene (DBU).

Any suitable copper salt may be used, for example, CuC^.

When R¹ and R² do not contain nitrogen then a source of nitrogen is required if the azaphthalocyanine ring is to be formed. Suitable sources of nitrogen include ammonia and urea.

Compounds of Formula (1 ), Formula (2) and Formula (3) may be prepared by methods well known in the art. They are also commonly commercially available. Compounds of Formula (1 ) and (2) may be purchased as a mixture of predetermined composition.

A second aspect of the invention provides copper-azaphthalocyanines and salts thereof obtainable by means of a process according to the first aspect of the invention.

Preferences are as described and preferred in the first aspect of the invention.

Preferably the second aspect of the invention provides copper- azaphthalocyanine dyes and salts thereof comprising a component of Formula (4):

Formula (4)

wherein

a represents the total number of sulfonic acid residues linked to the azaphthalocyanine ring in the a-position and is in the range of from 0.5 to 3;

β represents the total number of sulfonic acid residues linked to the azaphthalocyanine ring in the β-position and is in the range of from 1 to 3; and

a plus β is in the range of from 2.5 to 3.5;

q, the average number of pyridine rings incorporated into the phthalocyanine ring system, is 0.5 to 1 .5; and

a plus β plus q is 4.

Since the dyes of the second aspect of the invention are obtainable by a process as described in the first aspect of the invention they will be a disperse mixture and so the values of a and β will be an average rather than an integer.

The skilled person would also appreciate that the compounds of Formula (4) as a disperse mixture would in addition to the component shown above contain other ring systems. Thus, in addition to the monoazo component shown above the compounds of Formula (4) would also have phthalocyanine, diazaphthalocyanine, triazaphthalocyanine and tetrazaphthalocyanine components.

Acid or basic groups on the compounds disclosed in this invention, particularly acid groups, are preferably in the form of a salt. Thus, all Formulae shown herein include the compounds in salt form.

Preferred salts are alkali metal salts, especially lithium, sodium and potassium, ammonium and substituted ammonium salts (including quaternary amines such as ((CH₃) N⁺) and mixtures thereof. Especially preferred are salts with sodium, lithium, ammonia and volatile amines, more especially sodium salts.

The mixtures of copper-phthalocyanine dyes may be converted into a salt using known techniques.

Compounds disclosed in this specification may exist in tautomeric forms other than those shown. These tautomers are included within the scope of the present invention.

The compounds of the present invention can be used as dyes in their own right. However preferably they are used to prepare ink jet dyes carrying sulfonamide substituents on the ring.

Thus a third aspect of the invention provides a process for the preparation of azaphthalocyanine sulfonamide ink-jet dyes said process comprising the steps of

(i) reacting the azaphthalocyanine of the second aspect of the invention with a chlorinating agent to convert the sulfonic acid substituents into sulfonyl chloride; and (ii) reacting the product of step (i) with ammonia and/or one or more amines.

The chlorinating agent used in stage (i) may be any suitable chlorinating agent such as, for example, chlorosulfonic acid, phosphorous pentachloride, phosphorus oxychloride, phosphorous trichloride or thionyl chloride. Preferably the chlorinating agent comprises a mixture of chlorosulfonic acid and phosphorus oxychloride. Preferably the ratio of chlorosulfonic acid to phosphorus oxychloride is in the range of 25 molar equivalents to 0.5 molar equivalents and more preferably 12.5 molar equivalents to 1 .0 molar equivalent.

When the chlorinating agent comprises a mixture of chlorosulfonic acid and phosphorus oxychloride (as preferred above) then the preferred molar ratio of the chlorinating agent to the compounds of Formula (4) is 100 molar equivalents to 1 .0 molar equivalent and more preferably 50 molar equivalents to 1 .0 molar equivalent.

Preferably chlorination is performed at a temperature in the range of from 90-180 ^° C, more preferably 120-150 ^° C, especially 130-148 ^° C and more especially 135-145 ^° C.

Preferably the chlorination is performed for 0.5 to 16 hours, more preferably 1 to 8 hours and especially 1 .5 to 5 hours.

The length of time for which the chlorination is performed depends on the temperature used. For example higher temperatures require less time and lower temperatures require more time. In a preferred embodiment chlorination is performed at a temperature of 135-145 ^° C for a time of from 1 .5 to 8 hours and more preferably of from 2 to 7 hours.

Condensation of the product of stage (i) with ammonia and/or one or more amines in stage (ii) is preferably performed at a temperature of from 10-80 C, and more preferably at a temperature of from 20-60 ^° C for a time of from 1 to 14 hours and more preferably of from 2 to 6 hours. The reactions with ammonia and the amine(s) can be carried out sequentially though preferably they are reacted at the same time.

The amine reacted with the copper-azaphthalocyanines carrying sulfonyl chloride groups in stage (ii) may be any amine able to react with a sulfonyl chloride to yield a sulfonamide.

The amine reacted with the mixture of azaphthalocyanine or metallo- azaphthalocyanines carrying sulfonyl chloride groups in stage (ii) may be any amine able to react with a sulfonyl chloride to yield a sulfonamide.

Preferably the amine(s) is/are of Formula (5) and Formula (6)

NHR³R⁴

Formula (5) NHR⁵R⁶

Formula (6)

wherein:

R³ and R⁴ are selected from the group consisting of H, optionally substituted alkyl (optionally interrupted by one or more hetero atoms); optionally substituted aryl; and optionally substituted heterocyclylene (including optionally substituted heteroaryl); and

R⁵ and R⁶ are selected from the group consisting of optionally substituted alkyl (optionally interrupted by one or more hetero atoms); optionally substituted aryl; and optionally substituted heterocyclylene (including optionally substituted heteroaryl).

More preferably R³ and R⁴ are selected from the group consisting of H and optionally substituted Ci-salkyl, especially Ci-salkyl carrying one or more groups selected from the group consisting of -OH, -SO3H, -CO₂H and -PO3H₂.

It is especially preferred that R³ and R⁴ are H or optionally substituted Ci- alkyl, more especially that one of R³ and R⁴ is H or methyl and the other is Ci- ₄alkyl carrying at least one and more preferably two -OH substituents.

It is especially preferred that the amine of Formula (5) is 3-aminopropane- 1 ,2-diol.

A preferred amine of Formula (6) is of Formula (7):

NHR⁷-L-NR⁸R⁹

Formula (7)

wherein:

L is a divalent linking group;

R⁷ is H or optionally substituted alkyl;

R⁸ and R⁹ are independently H, optionally substituted alkyl (optionally interrupted by one or more hetero atoms), optionally substituted aryl or optionally substituted heterocyclyl.

Thus preferably in step (ii) the product of step (i) is reacted with an amine of Formula (7), and optionally ammonia and/or another amine

Preferably L, the divalent linking group, is selected from the group consisting of: optionally substituted alkylene (optionally interrupted by one or more hetero atoms); optionally substituted arylene; and optionally substituted heterocyclylene (including optionally substituted heteroarylene).

More preferably L is optionally substituted alkylene, especially optionally substituted Ci_-4alkylene, more especially unsubstituted Ci_-4alkylene and particularly -CH₂CH₂-.

Preferably R⁷ is H or optionally substituted Ci_-4alkyl, more preferably H, methyl or ethyl, especially H or methyl and more especially H. Preferably R⁸ and R⁹ are independently H, optionally substituted Ci_-4alkyl or optionally substituted heterocyclyl.

Preferably R⁸ is H or optionally substituted Ci_-4alkyl, more preferably H, methyl or ethyl, especially H or methyl and more especially H .

Preferably R⁹ is an optionally substituted triazinyl group (where preferably the triazinyl group or substituent thereon carries at least one water solubilising group selected from the group consisting of -SO₃H, -CO2H and -PO3H2).

More preferably R⁹ is a group of Formula (8)

Formula (8)

wherein:

A is selected from the group consisting of -OR¹⁰, -SR¹⁰, -NR¹⁰R^{1 1} ;

B is selected from the group consisting of -OR¹², -SR¹², -NR¹²R¹³;

R¹⁰, R^{1 1} , R¹² and R¹³ are independently H, optionally substituted alkyl, optionally substituted aryl or optionally substituted heterocyclyl provided that at least one of the groups represented by R¹⁰, R^{1 1} , R¹² and R¹³ carries at least one substituent selected from the group consisting of -SO3H, -

Preferred groups represented by A and B may be independently selected from the group consisting of -OH, -NH₂, -NHCH₃, -N(CH₃)₂, -NHC₂H₄SO₃H, - N(CH₃)C₂H₄SO₃H, -NC₃H₆SO₃H, -NHdisulfophenyl, -NHsulfophenyl, -NHcarboxyphenyl or -NHdicarboxyphenyl, -NHsulfonaphthyl, -NHdisulfonaphthyl, -NHtrisulfonaphthyl, -NHcarboxynaphthyl, NHdicarboxynaphthyl,

NHtricarboxynaphthyl-NHsulfoheterocyclyl, -NHdisulfoheterocyclyl or

-NHtrisulfoheterocyclyl.

It is especially preferred th f Formula (9)

Formula (9)

wherein:

R¹⁰ is H or optionally substituted Ci_-4alkyl

R^{1 1} is H or optionally substituted Ci_-4alkyl

R¹² is H or optionally substituted Ci_-4alkyl R¹³ is optionally substituted alkyl, optionally substituted aryl or optionally substituted heterocyclyl carrying at least one substituent selected from the group consisting of -SOsH, -CO2H and -PO3H2.

Preferably R¹⁰ is H or unsubstituted Ci_-4alkyl, more preferably R¹⁰ is H or methyl, especially H.

Preferably R¹¹ is H or unsubstituted Ci_-4alkyl, more preferably R¹¹ is H or methyl, especially H.

Preferably R¹² is H or unsubstituted Ci_-4alkyl, more preferably R¹² is H or methyl, especially H.

In a preferred embodiment R¹⁰, R^{1 1} and R¹² are all independently either H or methyl. More preferably R¹⁰ and R¹¹ are methyl and R¹² is H

Preferably R¹³ is optionally substituted aryl carrying at least one substituent selected from the group consisting of -SOsH, -CO2H and -PO3H2. More preferably R¹³ is an aryl group (particularly a phenyl group) carrying 1 -3, especially 2, -SO3H or -CO2H groups.

Most preferably the amine of Formula (6) is of Formula (10):

Formula (10)

It is particularly preferred that in the third aspect of the invention in step (ii) the product of step (i) is reacted with 3-aminopropane-1 ,2-diol and an amine of Formula (10).

The ink-jet dyes so formed from the intermediate according to the second aspect of the invention display an outstanding balance of solubility, storage stability and fastness to water, ozone and light.

A fourth aspect of the invention provides azaphthalocyanine sulfonamide ink- jet dyes obtainable by means of a process according to the third aspect of the invention.

According to a fifth aspect of the present invention there is provided a composition comprising a azaphthalocyanine as described in the second and fourth aspects of the invention and a liquid medium.

Preferred compositions according to the fifth aspect of the invention comprise:

(a) from 0.01 to 30 parts of dyes as described in the second, third and fourth aspects of the invention; and

(b) from 70 to 99.99 parts of a liquid medium; wherein all parts are by weight.

Preferably the number of parts of (a) + (b) = 100.

The number of parts of component (a) is preferably from 0.1 to 20, more preferably from 0.5 to 15, and especially from 1 to 5 parts. The number of parts of component (b) is preferably from 80 to 99.9, more preferably from 85 to 99.5 and especially from 95 to 99 parts.

Preferably component (a) is completely dissolved in component (b). Preferably component (a) has a solubility in component (b) at 20°C of at least 10%. This allows the preparation of liquid dye concentrates that may be used to prepare more dilute inks and reduces the chance of the dye precipitating if evaporation of the liquid medium occurs during storage.

Preferred liquid media include water, a mixture of water and organic solvent and organic solvent free from water. Preferably the liquid medium comprises a mixture of water and organic solvent or organic solvent free from water.

When the liquid medium (b) comprises a mixture of water and organic solvent, the weight ratio of water to organic solvent is preferably from 99:1 to 1 :99, more preferably from 99:1 to 50:50 and especially from 95:5 to 80:20.

It is preferred that the organic solvent present in the mixture of water and organic solvent is a water-miscible organic solvent or a mixture of such solvents. Preferred water-miscible organic solvents include Ci-6-alkanols, preferably methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butanol, n- pentanol, cyclopentanol and cyclohexanol; linear amides, preferably dimethylformamide or dimethylacetamide; ketones and ketone-alcohols, preferably acetone, methyl ether ketone, cyclohexanone and diacetone alcohol; water-miscible ethers, preferably tetrahydrofuran and dioxane; diols, preferably diols having from 2 to 12 carbon atoms, for example ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol and thiodiglycol and oligo- and poly- alkyleneglycols, preferably diethylene glycol, triethylene glycol, polyethylene glycol and polypropylene glycol; triols, preferably glycerol and 1 ,2,6-hexanetriol; mono-Ci- 4-alkyl ethers of diols, preferably mono-Ci_-4-alkyl ethers of diols having 2 to 12 carbon atoms, especially 2-methoxyethanol, 2-(2-methoxyethoxy)ethanol, 2-(2-ethoxyethoxy)-ethanol, 2-[2-(2-methoxyethoxy)ethoxy]ethanol, 2-[2-(2- ethoxyethoxy)-ethoxy]-ethanol and ethylene glycol monoallyl ether; cyclic amides, preferably 2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, caprolactam and 1 ,3-dimethylimidazolidone; cyclic esters, preferably caprolactone; sulfoxides, preferably dimethyl sulfoxide; and sulfones. Preferably the liquid medium comprises water and 2 or more, especially from 2 to 8, water-miscible organic solvents.

Especially preferred water-miscible organic solvents are cyclic amides, especially 2-pyrrolidone, N-methyl-pyrrolidone and N-ethyl-pyrrolidone; diols, especially 1 ,5-pentane diol, ethylene glycol, thiodiglycol, diethylene glycol and t ethylene glycol; and mono-Ci_-4-alkyl and Ci_-4-alkyl ethers of diols, more preferably mono- Ci_-4-alkyl ethers of diols having 2 to 12 carbon atoms, especially 2-methoxy- 2-ethoxy-2-ethoxyethanol .

When the liquid medium comprises organic solvent free from water, (i.e. less than 1 % water by weight) the solvent preferably has a boiling point of from 30- 200°C, more preferably of from 40-150°C, especially from 50-125°C. The organic solvent may be water-immiscible, water-miscible or a mixture of such solvents. Preferred water-miscible organic solvents are any of the hereinbefore-described water-miscible organic solvents and mixtures thereof. Preferred water-immiscible solvents include, for example, aliphatic hydrocarbons; esters, preferably ethyl acetate; chlorinated hydrocarbons, preferably CH₂CI₂; and ethers, preferably diethyl ether; and mixtures thereof.

When the liquid medium comprises a water-immiscible organic solvent, preferably a polar solvent is included because this enhances the solubility of the copper azaphthalocyanine dyes in the liquid medium. Examples of polar solvents include Ci_-4-alcohols.

In view of the foregoing preferences it is especially preferred that where the liquid medium is organic solvent free from water it comprises a ketone (especially methyl ethyl ketone) and/or an alcohol (especially a Ci_-4-alkanol, more especially ethanol or propanol).

The organic solvent free from water may be a single organic solvent or a mixture of two or more organic solvents. It is preferred that when the liquid medium is organic solvent free from water it is a mixture of 2 to 5 different organic solvents. This allows a liquid medium to be selected that gives good control over the drying characteristics and storage stability of the ink.

Liquid media comprising organic solvent free from water are particularly useful where fast drying times are required and particularly when printing onto hydrophobic and non-absorbent substrates, for example plastics, metal and glass.

The liquid media may of course contain additional components conventionally used in ink jet printing inks, for example viscosity and surface tension modifiers, corrosion inhibitors, biocides, kogation reducing additives and surfactants which may be ionic or non-ionic.

Although not usually necessary, further colorants may be added to the ink to modify the shade and performance properties.

It is preferred that the composition according to the invention is ink suitable for use in an ink jet printer. Ink suitable for use in an ink jet printer is ink which is able to repeatedly fire through an ink jet printing head without causing blockage of the fine nozzles. To do this the ink must be particle free, stable (i.e. not precipitate on storage), free from corrosive elements (e.g. chloride) and have a viscosity which allows for good droplet formation at the print head.

Ink suitable for use in an ink jet printer preferably has a viscosity of less than 20cP, more preferably less than 10cP, especially less than 5cP, at 25°C.

Ink suitable for use in an ink jet printer preferably contains less than

500ppm, more preferably less than 250ppm, especially less than 100ppm, more especially less than 10ppm in total of divalent and trivalent metal ions (other than any divalent and trivalent metal ions bound to a colorant of Formula (1 ) or any other colorant or additive incorporated in the ink).

Preferably ink suitable for use in an ink jet printer has been filtered through a filter having a mean pore size below Ι Ομηη, more preferably below 3μηη, especially below 2μηη, more especially below 1 μηη. This filtration removes particulate matter that could otherwise block the fine nozzles found in many ink jet printers.

Preferably ink suitable for use in an ink jet printer contains less than

500ppm, more preferably less than 250ppm, especially less than 100ppm, more especially less than 10ppm in total of halide ions.

The inks may be incorporated in an ink jet printer as a high concentration cyan ink, a low concentration cyan ink or both a high concentration and a low concentration ink. In the latter case this can lead to improvements in the resolution and quality of printed images. Thus the present invention also provides a composition (preferably an ink) where component (a) is present in an amount of 2.5 to 7 parts, more preferably 2.5 to 5 parts (a high concentration ink) or component (a) is present in an amount of 0.5 to 2.4 parts, more preferably 0.5 to 1 .5 parts (a low concentration ink).

A sixth aspect of the invention provides a process for forming an image on a substrate comprising applying a composition, preferably ink suitable for use in an ink jet printer, according to the fifth aspect of the invention, thereto by means of an ink jet printer.

The ink jet printer preferably applies the ink to the substrate in the form of droplets that are ejected through a small orifice onto the substrate. Preferred ink jet printers are piezoelectric ink jet printers and thermal ink jet printers. In thermal ink jet printers, programmed pulses of heat are applied to the ink in a reservoir by means of a resistor adjacent to the orifice, thereby causing the ink to be ejected from the orifice in the form of small droplets directed towards the substrate during relative movement between the substrate and the orifice. In piezoelectric ink jet printers the oscillation of a small crystal causes ejection of the ink from the orifice. Alternately the ink can be ejected by an electromechanical actuator connected to a moveable paddle or plunger. The substrate is preferably paper, plastic, a textile, metal or glass, more preferably paper, an overhead projector slide or a textile material, especially paper.

Preferred papers are plain or treated papers which may have an acid, alkaline or neutral character. Photographic quality papers are especially preferred.

A seventh aspect of the present invention provides a material preferably paper, plastic, a textile, metal or glass, more preferably paper, an overhead projector slide or a textile material, especially paper more especially plain, coated or treated papers printed with dyes according to the second or fourth aspects of the invention, a composition according to the fifth aspect of the invention or by means of a process according to the sixth aspect of the invention.

It is especially preferred that the printed material of the seventh aspect of the invention is a print on a photographic quality paper printed using a process according to the sixth aspect of the invention.

A final aspect of the present invention provides an ink jet printer cartridge comprising a chamber and a composition, preferably ink suitable for use in an ink jet printer, wherein the composition is in the chamber and the composition is as defined and preferred in the fifth aspect of the present invention. The cartridge may contain a high concentration ink and a low concentration ink, as described in the fifth aspect of the invention, in different chambers.

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

Example 1

A mixture of 3-sulfophthalic acid and 4-sulfophthalic acid (147.6g of a 50% aqueous solution in water supplied by Acros®), in an isomer ratio of -23:77 (as determined by integration of 1 H-NMR spectrum) and sulfolane (500g) were heated at 160°C to distil off water. The mixture was cooled to 100°C and pyridine-2,3- dicarboxylic acid (17g, supplied by Acros®), urea (144g, supplied by Fisher), copper (II) chloride (1 1 .8g, supplied by Fisher) and ammonium molybdate tetrahydrate (12.4g, supplied by Fisher) were added. The reaction temperature was raised to 180°C over 2 hours, during which time the reaction mixture turned dark blue. The temperature was maintained at 180°C for 16 hours. The reaction mixture was cooled to 70°C, methanol (200ml) was added and the mixture was stirred at 65 to 70°C for 30 minutes. A dark blue solid was filtered off (whilst still hot) and washed with methanol (400ml). The resultant paste (240g) was added to water (1 L) containing concentrated hydrochloric acid (100ml) and stirred at 65 to 70°C for 1 hour. Solid sodium chloride (175g) was added in portions to effect precipitation of a blue solid, which was collected by filtration whilst still hot. This solid was washed with a solution comprising 20% brine (120ml) and concentrated hydrochloric acid (12ml). The paste (1 10g) was then added to water (600ml) and heated to 60 to 65°C. The solid was dissolved by raising the pH to 8.5 using concentrated sodium hydroxide solution. Solid sodium chloride (70g) was added to re-precipitate the blue solid, which was collected by filtration whilst still hot, and washed with 10% brine (100ml). The paste was then dried to give 67.7g of a blue solid.

Example 2

Stage 1

Preparation of the Intermediate Amine

Cyanuric chloride (9.23g) was stirred in ice/water (200g at 0 to 5°C with a few drops of calsolene oil). A solution of 2,5-disulfoaniline (13.8g) in water (50ml) at pH 5 to 6 was then added drop-wise with stirring. The reaction mixture was stirred at≤5°C and pH 5 to 6 for 2 hours. The pH was then raised to 7 with 2M sodium hydroxide solution and the temperature to 20 to 25°C and the reaction mixture was left for 1 hour. Dimethylamine (40%, 6.3ml) was added and the pH was adjusted to 8.5 to 9. The reaction mixture was then stirred at room temperature at pH 8.5 to 9 for 2 hours, then at 60°C for 1 hour and finally for 1 hour at 80°C before being allowed to cool overnight. Ethylenediamine (33ml) was added and the reaction was stirred at 80°C for a further 2 hours. Volume adjusted to 200ml by rotary evaporator, NaCI (20g) and the pH was lowered to 1 with concentrated HCI. The precipitate which formed was collected by filtration, washed with 20% NaCI and slurried in methanol (170ml) and water (9ml) at 60°C for 1 hour. The solid was then collected by filtration, washed with methanol (25ml) and dried to give the product (18.5g).

Stage 2

Phosphorus oxychloride (6.2g, 0.04mol) was added drop-wise over 5 minutes to chlorosulfonic acid (60g, 0.5mol) at room temperature. Sulfonated azaphthalocyanine sodium salt (as prepared in Example 1 , 9.3g, 0.01 mol) was added slowly (as a solid) over 10 minutes and the reaction was heated at 130°C for 6 hours and then left to cool overnight. The next day the reaction was drowned out into ice (400g) at <5°C, left to stir for 15 minutes and then the precipitate was collected by filtration and washed with ice cold saturated brine to give a damp solid. The damp solid was added to a mixture of the intermediate amine prepared in stage 1 (5.4g, 0.01 mol) and 3-aminopropane-1 ,2-diol (5.6g, 0.06mol) in water (100ml) at <5°C and pH 8.5. The pH of the reaction mixture was raised to 9.5 (2M NaOH), then the mixture was warmed to 50-55°C while maintaining the pH at 9.5 by the careful addition of NaOH. The temperature was then raised to 80°C, the pH was raised to 12 (2M NaOH) and the mixture left to stir for 0.5 hour, before cooling to 50°C and screening through Whatman GFF filter paper. The mixture was salted to 25% (NaCI) and the pH was lowered to 3.5 (c HCI). The solid was collected by filtration and re-dissolved in water (300ml), dialysed and dried in the oven at 60°

(9g).

Inks

The inks described in Tables A and B may be prepared using the compound of Example 2. The dye indicated in the first column is dissolved in 100 parts of the ink as specified in the second column on. Numbers quoted in the second column onwards refer to the number of parts of the relevant ink ingredient and all parts are by weight. The pH of the ink may be adjusted using a suitable acid or base. The inks may be applied to a substrate by ink jet printing.

The following abbreviations are used in Tables A and B:

PG = propylene glycol

DEG = diethylene glycol

NMP = N-methyl pyrrolidone

DMK = dimethyl ketone

IPA = isopropanol

2P = 2-pyrrolidone

MIBK = methylisobutyl ketone

P12 = propane-1 ,2-diol

BDL = butane-2,3-diol

TBT = tertiary butanol TABLE A

Dye Water PG DEG NMP DMK I PA 2P MIBK

2.0 80 5 6 4 5

3.0 90 5 5

10.0 85 3 3 3 6

2.1 91 8 1

3.1 86 5 4 5

1 .1 81 9 10

2.5 60 4 15 3 3 6 5 4

5 65 20 10 5

2.4 75 5 10 5 5

4.1 80 3 5 2 10

3.2 65 5 4 6 5 10 5

5.1 96 4

10.8 90 5 5

10.0 80 2 6 2 5 1 4

1 .8 80 5 15

2.6 84 1 1 5

3.3 80 4 10 6

12.0 90 7 3

5.4 69 2 20 2 1 3 3

6.0 91 4 5

TABLE B

Dye Water PG DEG NMP TBT BDL PI2

Content

3.0 80 20

9.0 90 5 5

1 .5 85 5 5 5

2.5 90 6 4

3.1 82 4 8 6

0.9 85 10 5

8.0 90 5 5

4.0 70 10 4 5 1 1

2.2 75 10 10 3 2

10.0 91 9

9.0 76 9 7 3 5

5.0 78 5 1 1 6

5.4 86 7 7

2.1 70 5 10 5 5 5

2.0 90 10

2 88 12

5 78 5 7 10

8 70 2 20 8

10 80 10 10

10 80 20

Claims

1 . A process for preparing a copper azaphthalocyanine and salts thereof which comprises cydising a compound of Formula (1 ) with a compound of Formula (2) and a compound of Formula (3):

Formula (1 ) Formula (2) Formula (3);

wherein:

NH O _N NH

Λ NH Λ O NH H

NH ^ O O _OR Ή O . _{A ND}

in the presence of a suitable copper salt and a nitrogen source (if required).

2. A process as claimed in claim 1 wherein R¹ and R² are both carboxy.

3. A process as claimed in either claim 1 or claim 2 wherein the molar ratio of the compound of Formula (1 ) to the compound of Formula (2) and the compound of Formula (3) is in the range of from 2:1 :1 to 1 :2:1 to 1 :1 :2.

4. A process as claimed in any one of the preceding claims wherein the molar ratio of the compound of Formula (1 ) to the compound of Formula (2) and the compound of Formula (3) is in the range of from 0.7:2.3:1 to 0.8:2.2:1 .

5. A process as claimed in any one of the preceding claims wherein the process is performed at a temperature in the range of from 170 to 200 ^° C for a time in the range of from 4 to 16 hours.

6. Copper-azaphthalocyanines and salts thereof obtainable by means of a process according to any one of claims 1 to 5.

7. Copper-azaphthalocyanine dyes and salts thereof according to claim 6 comprising a component of Formula (4):

Formula (4)

wherein

β represents the total number of sulfonic acid residues linked to the azaphthalocyanine ring in the β-position and is in the range of from 1 to 3; and a plus β is in the range of from 2.5 to 3.5;

q, the average number of fused pyridine rings in the phthalocyanine ring, is 0.5 to 1 .5; and

a plus β plus q is 4.

8. A process for the preparation of azaphthalocyanine sulfonamide ink-jet dyes said process comprising the steps of

(i) reacting the azaphthalocyanine as described in either claim 6 or claim 7 with a chlorinating agent to convert the sulfonic acid substituents into sulfonyl chloride; and

(ii) reacting the product of step (i) with ammonia and/or one or more amines.

9. A process according to claim 8 wherein in step (ii) the product of step (i) is reacted with 3-aminopropane-1 ,2-diol and an amine of Formula 10

Formula (10).

10. Azaphthalocyanine sulfonamide ink-jet dyes obtainable by means of a process according to either claim 8 or claim 9.

1 1 . A composition comprising a azaphthalocyanine as described in any one of claims 6, 7 or 10 and a liquid medium.

12. A composition as claimed in claim 1 1 which is ink suitable for use in an ink jet printer.

13. A process for forming an image on a substrate comprising applying an ink suitable for use in an ink jet printer according to claim 12 thereto by means of an ink jet printer.

14. Material printed with an azaphthalocyanine according to any one of claims 6, 7 or 10, a composition according either claim 1 1 or claim 12 or by means of a process according to claim 13.

15. A printed material as claimed in claim 14 which is a print on a photographic quality paper printed using a process according to claim 13.