WO2008001036A2

WO2008001036A2 - Compound, composition and use

Info

Publication number: WO2008001036A2
Application number: PCT/GB2007/002025
Authority: WO
Inventors: Rachel Anne James
Original assignee: Fujifilm Imaging Colorants Limited
Priority date: 2006-06-28
Filing date: 2007-06-04
Publication date: 2008-01-03
Also published as: GB0819432D0; GB0612784D0; GB2450661B; WO2008001036A3; GB2450661A

Abstract

A process for ink jet printing a substrate using an ink comprising a water- soluble compound of Formula (1) which is free from fibre-reactive groups: wherein: each R1 and R2 independently is a substituent other than H; m and n each independently has a value of 0 to 4; (m+n) has a value of at least 1; X and Y each independently is O, S, SO, SO2 or -NR3-; and R3 is H or optionally substituted alkyl, aryl or heteroaryl.

Description

COMPOUND, COMPOSITION AND USE

This invention relates to a process for the coloration of substrates by means of an ink jet printer and to inks suitable for use in the process.

Ink Jet printing ("IJP") 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. IJP has been used for a wide variety of substrates, including papers and textiles.

Canadian patent application 2,531 ,625 describes textile ink jet printing processes using aqueous inks containing reactive dyes. Firstly the textile is treated with an ink-receptive pre-treatment composition, usually containing a strong alkali. The alkali removes the hydrogen atom from hydroxyl groups in sugars making up the textile material and renders them reactive towards dyes contained in the ink. When the ink is applied to the treated textile material, the nucleophilic, deprotonated hydroxyl groups react with the reactive dye to form a covalent bond there between. Typically the textile is heated to a temperature around 100⁰C using saturated steam in order to facilitate this covalent bond formation. Finally the printed textile is washed to remove the pre-treatment composition and unfixed dye and then dried.

Small defects in printing accuracy, shade and resolution can be tolerated much more readily on textiles than they can on the printing media used in the home and in offices. The printing resolution required for textile printing is generally does not need to be so high as for photographic media. There is in fact little incentive to attempt very high resolution on textiles because the natural unevenness of the textile surface and the presence of pre-treatment compositions limit what can be achieved. Printing in the home and office environment is very different from textile printing. Applying strong alkali to substrates in the home and office is impractical, also steaming printed articles and washing them to remove unfixed dye are not practical. The superior surfaces offered by media used in the home and small offices (e.g. printing papers, photographic media and the like) can take full advantage of improvements in inks and ink jet printing processes.

In an increasingly cost conscious and competitive ink jet market, it is desirable for inks to be as cheap as possible. Desirably the inks produce brightly coloured prints with good fastness properties. A particular problem with many inks used in the home and office environment is that they fade quickly, particularly on contact with ozone. Fading is a particular problem with photographs because they are on display and spend long periods bathed in light and in contact with oxidising gases. Also the requirement for storage stable inks is more demanding in the home and office environment than in the field of textile printing. In the home environment printers are used less frequently than in say a textile printing factory and so inks need to be stable for longer periods of time. In the office environment ink turnover is often quick, but the resolution required is often higher than that for say printing children's homework or printing textiles. Ink storage stability is therefore more of an issue for printers used in the home or office environment than it would be for printers used for textile printing where the ink turnover is rapid and the rougher substrate means resolution demands are lesser. It has now surprisingly been found that certain yellow compounds provide valuable colorants for ink jet printing inks which are particularly valuable for use in the demanding home and office environments.

According to a first aspect of the present invention there is provided a process for printing an image on a substrate comprising applying to the substrate by means of an ink jet printer an ink comprising a water-soluble compound of Formula (1 ) which is free from fibre-reactive groups:

Formula (1 ) wherein: each R¹ and R² independently is a substituent other than H; m and n each independently has a value of 0 to 4; (m+n) has a value of at least 1 ;

X and Y each independently is O, S, SO, SO₂ or -NR³-; and R³ is H or optionally substituted alkyl, aryl or heteroaryl. In one embodiment m and n each independently has a value of 1 to 4.

Preferably m has a value of 1 or 2, especially 2. Preferably n has a value of 1 or 2, especially 1.

Preferably the compound of Formula (1 ) has at least one sulpho group. In one embodiment the compound of Formula (1 ) has from 1 to 4 sulpho groups, preferably 1 to 3 sulpho groups, especially 2 to 3 sulpho groups. In another embodiment the compound of Formula (1 ) has at least one carboxy group, for example 1 or 2 carboxy groups. In a further embodiment the compound of Formula (1 ) has at least one carboxy group and at least one sulpho group.

Preferably at least one of the groups represented by R¹ and R² is a sulpho group. Preferred optionally substituted aryl groups are optionally substituted phenyl and optionally substituted naphthyl.

Preferred optionally substituted heteroaryl groups are optionally substituted pyrrole, furan, thiophene, pyrazole, imidazole, triazole, thiazole, thiadiazole, pyridine, pyrimidine and pyrazine groups. In a preferred embodiment: (i) at least one of the groups represented by R¹ and R² is a sulpho group; and

(ii) at least one of the groups represented by R¹ is Ci_-4-alkyI or Ci_-4- alkoxy.

When any of the groups represented by R¹ or R² is a substituent other than H it is preferably C_1-8-alkyl, Ci_-8-alkoxy, NR⁴R⁵, NHCOR⁴, NHCONR⁴R⁵, -C(O)R⁴, -C(O)OR⁴, -C(O)NR⁴R⁵, PO₃H₂, -SR⁴, -SO₂R⁴, -SO₂NR⁴R⁵, -SOR⁴, sulpho, carboxy, CF₃, CN, NO₂, phenyl or halogen, wherein R⁴ and R⁵ are each independently H, Ci_-4-alkyl or Ci_₄-alkyl carrying a hydroxyl, carboxy or sulpho group, or R⁴ and R⁵ together with the nitrogen atom to which they are attached form an optionally substituted 5- or 6-membered ring, or Ci_-8-alkyl, Ci-s-alkoxy or phenyl carrying any of the foregoing. m is preferably 1 , 2 or 3, more preferably 2. n is preferably 1 , 2 or 3, more preferably 1.

X is preferably O, -NR³- or S, more preferably O. When X is O or S it is preferred that at least one of the groups represented by R¹ is an electron donating group, more preferably a C_1-8-alkyl, C_1-8-alkoxy, NR⁴R⁵, NHCOR⁴, NHSO₂R⁴,

NHCONR⁴R⁵, OH, OCOR⁴Or -SR⁴ group, wherein R⁴ and R⁵ are as hereinbefore defined, especially Ci_-8-alkoxy and more especially methoxy or ethoxy. This preference arise because when X is O or S the shade of compounds of Formula

(1 ) is often shifted towards the greenish side of yellow. The presence of an electron donating group represented by at least one of the R¹ groups makes the shade more to the reddish, often giving a more neutral yellow or an attractive reddish-yellow shade.

Y is preferably O or -NR³-, more preferably -NR³-, wherein R³ is as hereinbefore defined.

Preferred optionally substituted alkyl groups are optionally substituted Ci_-8- alkyl, more preferably optionally substituted Ci_-4-alkyl, for example methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, optionally substituted by, for example, a hydroxy, halogen, carboxy or sulpho group. Examples of optionally substituted alkyl groups include trifluoromethyl, hydroxyethyl, sulphoethyl, sulphopropyl and carboxyethyl.

Preferably R¹ and R² are each independently sulpho, carboxy, Ci_-4-aIkyl or C_1-4-alkoxy. R³ is preferably C_1-4-alkyl carrying a sulpho group.

Preferred optionally substituted 5- or 6-membered rings include, thiophene, pyrazole, imidazole, triazole, thiazole, thiadiazole and pyridine rings.

Preferred optionally substituted aryl groups are optionally substituted phenyl and optionally substituted naphthyl. Preferred optional substituents for the abovementioned aryl group include Ci_-8-alkyl, Ci_-8-alkoxy, NR⁴R⁵, NHCOR⁴, NHCONR⁴R⁵, NHCOR⁴, -SR⁴, -C(O)R⁴, -C(O)OR⁴, -C(O)NR⁴R⁵, PO₃H₂,carboxy, sulpho, -SO₂R⁴, -SO₂NR⁴R⁵, -SOR⁴, -SO₃H, CF₃, CN, NO₂ and halogen, wherein R⁴ and R⁵ are as hereinbefore defined. In a preferred embodiment of the first aspect of the present invention the compound of Formula (1 ) is as defined hereinbelow in relation to the second aspect of the present invention.

It is especially preferred that the compounds of Formula (1 ) are yellow in colour. Preferably the compound of Formula (1 ) has a solubility in water at 2O⁰C of

0.1 to 15 wt %, more preferably 0.2 to 5 wt %, especially 0.3 to 3wt %.

The printing process of the present invention has the advantage that it may use compounds which are simpler and therefore cheaper than those described in Canadian patent application 2,531 ,625. Also the inks used in the process have good storage stability. While not wishing to be limited to any particular theory, the absence of fibre-reactive groups may play a part in this stability. For example the chlorotriazine and beta sulphatoethyl sulphone reactive groups used in the dyes of Canadian patent application 2,531 ,625 are naturally labile and over time they may degrade, generating acids and other species which may affect the stability of the ink. In coarse textile printing this might be tolerable, but for printing photographs where high definition and true colours are very important it can be a problem. Furthermore, the resultant prints are generally very bright and show good resistance to fade on contact with ozone.

The compounds of Formula (1) also have good operability in ink jet printers. Inks comprising compounds of Formula (1 ) demonstrate a low tendency to crust over or block nozzles when printed from an ink jet printer.

Compounds of Formula (1 ) are free from fibre-reactive groups because no such groups are required. The term fibre-reactive group is well known in the textile art and is described for example in EP 0356014 A1. Fibre-reactive groups are capable, under alkaline conditions, of reacting with the hydroxy! groups present in cellulosic fibres or with the amino groups present in natural fibres to form a covalent linkage between the fibre and the dye.

The compounds of Formula (1) may be prepared by, for example, by condensing an amine of formula H₂N-R³ with a compound of Formula (2):

wherein R¹, R², m, n and X are as hereinbefore defined. Typically temperatures of 11O⁰C to 16O⁰C are used for the condensation, with reaction times typically lasting from 1.5 to 5 hours. Preferably a zinc salt is present, e.g. zinc acetate. If desired the dicarboxylic acid equivalent of the compound of Formula (2) may be used instead, i.e. where there anhydride ring has been opened to give two carboxylic acid groups. Examples of suitable amines of formula H₂N-R³ include amino acids, for example taurine, 1-amino-3-sulphopropane, aspartic acid, glutamic acid, arginine, sulphanilic acid, metanilic acid and 1-amino-3-carboxy benzene.

Water-soluble compounds of Formula (1 ) may also be prepared by sulphonation of the corresponding compound which lacks or has fewer sulpho groups. Oleum may be used as a sulphonating agent.

Compounds of Formula (1 ) where Y is S may be prepared by ring opening the corresponding anhydride where Y is O and treating the resultant dicarboxylic acid with a sulphurising agent and then ring closing again.

Compounds of Formula (1 ) where Y is SO or SO₂ may be prepared by oxidising the corresponding compound where Y is S, e.g. with a peroxide.

The compounds of Formula (2) may be prepared by the general method of Peters and Behesti in the Journal of the Society of Dyers and Colorists, 1989, 105, 29.

Compounds of Formula (1) may also be prepared by heating the diazonium salt of a compound of the Formula (3) in the presence of copper or a copper salt:

Formula (3) wherein R¹, R², m, n, X and Y are as hereinbefore defined and one of Z¹ and Z² is H and the other is NH₂. Temperatures of 6O⁰C to 100⁰C are typically used. Suitable copper salts include CuSO₄ and copper (II) acetate.

Certain of the compounds of Formula (3) may be prepared by condensing the corresponding 4-bromo- or 4-chloronaphthalic acid compounds with optionally substituted 2-amino or 2-nitro phenols, thiophenols or anilines in organic solvents

(e.g. ethanol, butanol, glycolmonoalkyl ethers, dimethylformamide or pyridine) followed by reduction of the nitro group (if present) to an amino group.

Alternatively, one may react the corresponding 4-mercapto or 4-hydroxy naphthalic acid compounds with optionally substituted 2-nitrochlorobenzenes in an analogous manner and reduce the nitro group to an amino group using a suitable reducing agent, e.g. hydrogen and a transition metal catalyst.

The compounds of Formula (1) may be in the free acid or salt form.

Preferred salts are, for example alkali metal salts, (especially lithium, sodium, potassium), ammonium, substituted ammonium and mixed salts thereof.

Preferred metal salts are those with sodium, lithium, ammonium and substituted alkyl ammonium salts.

Preferred ammonium and substituted alkyl ammonium salts have cations of the formula ⁺NV₄ wherein each V independently is H or optionally substituted alkyl, or two groups represented by V are H or optionally substituted alkyl and the remaining two groups represented by V, together with the N atom to which they are attached, form a 5- or 6- membered ring

Preferably each V independently is H or Ci_-4-aIkyl, more preferably H, CH3 or CH2CH₃, especially H. Preferred cyclic cations comprise a morpholinyl, pyridinyl pr piperidinyl ring.

Examples of cations include ⁺NH₄, morpholinium, piperidinium, pyridinium, (CHa)₃N⁺H, (CHs)₂N⁺H₂, H₂N⁺(CH₃)(CH₂CH₃), CH₃N⁺H₃, CH₃CH₂N⁺H₃, H₂N⁺(CH₂CHa)₂, CH₃CH₂CH₂N⁺H₃, (CHa)₂CHN⁺H₃, N⁺(CH₃J₄, N⁺(CH₂CHs)₄, N-methyl pyridinium, N,N-dimethyl piperidinium and N,N-dimethyl morpholinium. It is especially preferred that the compounds of Formula (1) are in the form of a sodium, lithium, potassium, ammonium, substituted ammonium salt or mixtures thereof.

The compounds of Formula (1) exist in various tautomeric forms and tautomers are included within the scope of Formula (1 ). According to a second aspect of the present invention there is provided a water-soluble compound of Formula (1 ) as hereinbefore defined, which is free from fibre-reactive groups, with the provisos that:

(i) at least one of the groups represented by R¹ and R² is a sulpho group; and (ii) at least one of the groups represented by R¹ is Ci_-4-alkyI or C_1-4- alkoxy.

In the compounds of the second aspect of the present invention Y is preferably -NR³- wherein R³ is C-i_-4-alkyl carrying a sulpho and/or carboxy group. In particularly preferred compound of the invention, m is 2, one of the groups represented by R¹ is C_1-4-alkyl or C-_M-alkoxy and the other is sulpho, n is 1 , R² is a sulpho group, X is O and Y is -NR³- wherein R³ is C_1-4-alkyl carrying a sulpho and/or carboxy group.

The compounds of Formula (1 ) may be used as the sole colorant in inks because of their bright colour and good fastness properties. However, if desired, one may combine the present compounds with one or more further colorants if a different shade is required for a particular end use. When further colorants are included in the ink these are preferably selected from yellow, magenta, cyan and black colorants and combinations thereof, most preferably yellow or magenta colorants and combinations thereof.

According to a third aspect of the present invention there is provided a composition comprising; a) two or more water-soluble compounds of Formula (1 ) as defined in the first aspect of the present invention; or b) one or more water-soluble compound of Formula (1 ) as defined in the first aspect of the present invention and one or more colorants other than a water-soluble compound of Formula (1 ) as defined in the first aspect of the present invention.

Preferably the water-soluble compound of Formula (1 ) present in the composition is as defined in the second aspect of the present invention.

Preferably the composition according to the third aspect of the present invention is mixed so as to provide a uniform colour.

The colorant other than a water-soluble compound of Formula (1 ) (hereinafter referred to as "further colorant") is optionally a pigment or a dye. Suitable further colorants are listed in the Colour Index International.

The amounts of the compound and further colorant(s) present in the composition according to the third aspect of the present invention may be selected so as to adjust the shade or other properties as desired.

Preferred further colorants include yellow, magenta, cyan and black pigments and yellow, magenta, cyan and black dyes.

Suitable further colorants include, for example, yellow pigments, e.g. C.I. Pigment Yellow 55, 74, 93, 109, 110, 128, 138, 150, 151 , 154, 155, 180 and 185; yellow dyes, for example, C.I. Acid Yellow 17, 19, 23, 25, 32, 40, 42, 44, 49, 61 , 127, 151 , 199, 219; C.I. Direct Yellow 8, 11 , 12, 27, 28, 29, 44, 50, 85, 86, 96, 100, 106, 132, 142, 144, 173, the yellow dyes disclosed in granted US patent 6,320,031 , 6,068,687, US patent application publication No 2004-068102 (especially example 1 at [0157]), PCT application publication Nos WO2005- 160937 (especially examples Yellow R1 and R2 at [0028] and [0029]), WO2005- 5 007752 (especially example 1 at [0024]) and WO2002-075573 and salts thereof; magenta pigments, for example C.I. Pigment Red 122, 202, 209 and C.I. Pigment Violet 19; magenta dyes, for example PRO-JET™ Fast Magenta 2, PRO-JET™ Magenta BTX, 3BOA, 2BTX and 1T; C.I. Acid Red 52 and 249; C.I. Reactive Red 180, 31 and 23; and C.I. Direct Red 227; cyan pigments, for example C.I. Pigmento Blue 15, 15:1 , 15:2, 15:3, 15:4, 15:6, 16 and 60; cyan dyes, for example phthalocyanine colorants, especially C.I. Direct Blue 86, 199 and C.I. Acid Blue 9, 99; black pigments, for example C.I. Pigment Black 7 and the self-dispersing black pigments sold under the Cab-O-Jet™ trade name by Cabot Corp (e.g. Cab-O-Jet 300); and black dyes, for example C.I. Food Black 2, C.I. Direct Black 19, 154,5 168, 195, C.I. Reactive Black 31 , PRO-JET™ Fast Black 2 and black dyes described in patents by Lexmark (for example EP 0 539,178 A2, examples 1 , 2, 3, 4 and 5), Orient Chemicals (for example EP 0 347 803 A2, pages 5 to 6, azo dyes 3, 4, 5, 6, 7, 8, 12, 13, 14, 15 and 16) and Seiko Epson Corporation.

It is preferred that the one or more further colorants for use in the 0 composition according to the third aspect of the invention comprise a water- soluble dye.

The composition according to the third aspect of the present invention preferably comprises:

(a) from 1 to 99, more preferably from 3 to 70 and especially from 5 to 50 parts5 in total of the water-soluble compound(s) of Formula (1 ) as defined in the first aspect of the present invention; and

(b) from 99 to 1 , more preferably from 30 to 97 parts and especially 95 to 50 parts in total of a water-soluble dye(s) other than a compound of Formula

(1 ); o wherein the parts are by weight and the sum of the parts (a) + (b) = 100.

The composition may contain a single water-soluble compound of Formula (1 ) as defined in the first aspect of the present invention or a mixture thereof. Similarly, the composition may contain in (b) a single water-soluble dye or a mixture of two or more water-soluble dyes other than a compound of Formula (1 ).5 The compounds and compositions according to the second and third aspects of the present invention may be, and preferably are, purified to remove undesirable impurities before they are incorporated into inks for ink jet printing. Conventional techniques may be employed for purification, for example ultrafiltration, reverse osmosis and/or dialysis. According to a fourth aspect of the present invention there is provided an ink for ink jet printing comprising:

(a) a water-soluble compound of Formula (1 ) as defined in the first aspect of the present invention, or a composition according to the third aspect of the invention; and

(b) a liquid medium comprising water and an organic solvent. Preferably the water-soluble compound of Formula (1 ) present in the ink is as defined in the second aspect of the present invention.

A preferred ink according to the fourth aspect of the present invention comprises:

(a) from 0.01 to 30 parts of a water-soluble compound of Formula (1 ) as defined in the first aspect of the present invention; and

(b) from 70 to 99.99 parts of a liquid medium comprising water and an organic solvent; wherein the parts are by weight and the number of parts of (a) and (b) = 100.

In the fourth aspect of the present invention the number of parts by weight of component (a) is preferably from 0.01 to 30, more preferably 0.1 to 20, especially from 0.5 to 15, and more especially from 1 to 5 parts. The number of parts by weight of component (b) is preferably from 99.99 to 70, more preferably from 99.9 to 80, especially from 99.5 to 85, and more especially from 99 to 95 parts. The number of parts (a) + (b) is 100 and all parts mentioned here are by weight.

In the fourth aspect of the present invention preferably component (a) is completely dissolved in component (b). Preferably component (a) has a solubility in component (b) at 20⁰C of at least 10% by weight. This allows the preparation of liquid dye concentrates which may be used to prepare more dilute inks and reduces the chance of the compound(s) of component (a) of the ink precipitating if evaporation of the liquid medium occurs during storage.

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 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 pentane-1 ,5-diol, 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-C_1-4-aIkyl ethers of diols, preferably mono-C-_M-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 ethyleneglycol monoallylether; cyclic amides, preferably 2-pyrrolidone, N-methyl-2- pyrrolidone, N-ethyl-2-pyrrolidone, caprolactam and 1 ,3-dimethylimidazolidone; cyclic esters, preferably caprolactone; sulphoxides, preferably dimethyl sulphoxide and sulpholane. Preferably the liquid medium comprises water and 2 or more, especially from 2 to 8, water-soluble 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, ethyleneglycol, thiodiglycol, diethyleneglycol and triethyleneglycol; and mono- C-ι-₄-alkyl and C^-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.

The water-immiscible organic solvent is preferably a polar solvent because this enhances solubility of the compound in the liquid medium. Examples of polar solvents include Ci_-4-alcohols. An especially preferred ink comprises:

(a) from 1 to 10 parts in total of water-soluble compound(s) of Formula (1 ) as defined in the first aspect of the present invention or a composition according to the third aspect of the invention;

(b) from 2 to 60, more preferably 5 to 40 parts of water-soluble organic solvent; and

(c) from 30 to 97, more preferably 40 to 85 parts water; wherein all parts are by weight and the sum of the parts (a) + (b) + (c) = 100.

The ink may also contain additional components conventionally used in ink jet printing inks, for example viscosity and surface tension modifiers, corrosion inhibitors, biocides, kogation reducing additives, anti-cockle agents to reduce paper curling and surfactants which may be ionic or non-ionic.

The pH of the ink is preferably from 4 to 11 more preferably from 7 to 10.

The viscosity of the ink at 25⁰C is preferably less than 5OmPa. s, more preferably less that 2OmPa. s and especially less than 5mPa.s. The ink according to the fourth aspect of the present invention preferably has a concentration of halide ions of less than 500 parts per million, more preferably less than 100 parts per million. It is especially preferred that the ink has less than 100, more preferably less than 50 parts per million of divalent and trivalent metals, wherein parts refer to parts by weight relative to the total weight of the ink. We have found that purifying the ink to reduce the concentration of these undesirable ions reduces nozzle blockage in ink jet printing heads, particularly in thermal ink jet printers.

The ink of the present invention preferably forms the yellow ink of a yellow, magenta, cyan and black ink set.

In the case of a typical dye-based ink set the magenta ink may contain for example C.I. Direct Red 227, C.I. Acid Red 52, 249 or Pro-Jet™ Fast Magenta 2, the cyan ink may contain for example C.I. Direct Blue 86, 199, C.I. Acid Blue 9 or Pro- Jet™ Fast Cyan 2 and the black ink may contain for example C.I. Direct Black 168, 199 or Pro-Jet™ Fast Black 2. (Pro-Jet is a trade mark of Fujifilm Imaging Colorants Limited).

In the case of a pigment-based ink set, each ink preferably contains a further colorant selected from the pigments indicated above as being suitable further colorants. The magenta inks may contain, for example, C.I Pigment 122, 202 and/or 209. The cyan ink may contain, for example, C.I. Pigment Blue 15:3, 15:4 and/or 16. The black may contain, for example, C.I. Pigment Black 7 and/or Cab-O- jet™ 300. The yellow ink may contain, for example, a compound of Formula (1 ) as defined in the first aspect of the present invention and one or more of the further yellow pigments indicated above as being suitable further colorants. Preferably the ink is as defined in the fourth aspect of the present invention.

The ink jet printer preferably applies the ink to the substrate in the form of droplets which 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 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.

The substrate is preferably a plain or treated paper which may have an acid, alkaline or neutral character. Examples of commercially available treated papers include: Photo Paper Pro (PR101), Photo Paper Plus (PP101 ), Glossy Photo Paper (GP401 ), Semi Gloss Paper (SG101 ), Matte Photo Paper (MP101 ), (all available from Canon); Premium Glossy Photo Paper, Premium Semi gloss Photo Paper, ColorLife™, Photo Paper, Photo Quality Glossy Paper, Double-sided Matte Paper, Matte Paper Heavyweight, Photo Quality InkJet Paper, Bright White InkJet Paper, Premium Plain Paper, (all available from Seiko Epson Corp); HP All- in-One Printing Paper, HP Everyday InkJet Paper, HP Everyday Photo Paper Semi-glossy, HP Office Paper, HP Photo Paper, HP Premium High-Gloss Film, HP Premium Paper, HP Premium Photo Paper, HP Premium Plus Photo Paper, HP Printing Paper, HP Superior InkJet Paper, (all available from Hewlett Packard Inc.); Everyday Glossy Photo Paper, Premium Glossy Photo Paper, (both available from Lexmark™ Inc.); Matte Paper, Ultima Picture Paper, Premium Picture Paper, Picture Paper, Everyday Picture Paper (available from Kodak Inc.). A fifth aspect of the present invention provides a substrate (preferably a paper) printed by the process of the first aspect of the present invention or with an ink according to the fourth aspect of the present invention.

According to a sixth aspect of the present invention there is provided an ink jet printer cartridge comprising a chamber and ink, wherein the ink is present in the chamber and the ink is as defined in the fourth aspect of the present invention.

According to a seventh aspect of the present invention there is provided an ink jet printer containing an ink jet printer cartridge, wherein the ink jet printer cartridge is as defined in the sixth aspect of the present invention.

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

Example 1

Preparation of Compound (1):

Compound (1)

Stage (a)

Intermediate (1) was prepared by the published method of AT. Peters and Y. S. S. Behesti in The Journal of the Society of Dyers and Colourists, 1989, 105, pages 29 to 35 (see compound VIII as described therein):

Intermediate (1 )

Stage (b)

A mixture of Intermediate (1 ) prepared in Stage (a) (3.125mmol, 0.9g), Zn(OAc)₂ (2mmol, 0.439g), imidazole (10g) and taurine (7mmol, 0.315g) was heated to 130 to 140⁰C for 2.5 hours. The hot reaction mixture was then drowned out into ethanol and stirred for 30mins. The mixture was then filtered to provide Compound (1 ) (1.3g) as a water-soluble orange solid. HPLC analysis showed the title product was a single species.

Example 2

Preparation of Compound (2):

Compound (2)

The product of Example 1 (1.3g, 3.1 mmol) was added gradually to 20% oleum (10ml) at 0-5⁰C and the mixture was stirred at this temperature for 3 hours. After this time HPLC indicated the presence of a mixture of two new compounds. The reaction mixture was then stirred for a further 16 hours while gradually warming to room temperature. After this time HPLC showed complete conversion to the more polar of the 2 new compounds. The reaction mixture was then drowned out into ice and the product isolated by salting (10% NaCI). The resultant yellow solid was redissolved in water at pH7 and dialysed to low conductivity to provide the title product (1.3g) having absorption maxima at 425 and 445nm.

Example 3

Preparation of Compound (3):

Compound (3)

The method of Example 1 was repeated except that in place of Intermediate (1) was used Intermediate 2 shown below.

Intermediate 2

Intermediate 2 was prepared as follows:

Stage (a)

A mixture of 4-chloro 1 ,8-naphthalic anhydride (17.4g, 0.075mol), 4-methoxy-2- nitrophenol (25g, 0.147mol), sodium hydroxide (3g, 0.075mol) and catalytic quantities of copper and copper (I) iodide in dimethyl formamide (20OmL) was heated at 140⁰C for 6h. The reaction mixture was then allowed to cool, added to ice water (70OmL) and stirred at 50⁰C for 30 mins. The mixture was filtered and the resultant yellow solid was slurried in hot ethanol and refiltered to provide Intermediate 3 as a pale brown solid (21.5g, 79%):

Intermediate 3

Stage (b)

Intermediate 3 (18g, 0.049mol) was added to a mixture of tin (II) chloride (24.4g,

0.108mol) and concentrated hydrochloric acid (10OmL) and the mixture was heated under reflux for 16 hours. The mixture was then allowed to cool, filtered and the resultant solid was washed repeatedly with warm water. The product was then slurried in hot ethanol and refiltered to provide intermediate 4 as a pale yellow solid (11.1g, 68%):

Intermediate 4 Stage (c)

Intermediate 4 (16.55g, 0.043mol) was stirred into a mixture of glacial acetic acid (13OmL), concentrated HCI (2OmL), and water (24mL) at 0-5⁰C. A solution of sodium nitrite (4.1g, 0.059mol) in water (5OmL) was added gradually over the course of 20 minutes and the mixture was stirred at 0-5⁰C for a further 2 hours. The resultant diazonium suspension was then added portionwise (over 90mins) to a boiling solution of copper (II) sulphate (34.5g, 0.138mol) in a mixture of water (50OmL) and glacial acetic acid (36mL). The resultant mixture was boiled for a further 30 minutes, cooled to room temperature and filtered to provide an orange powder. The powder was slurried in hot dimethyl formamide, allowed to cool and filtered to obtain Intermediate 2 as a yellow solid (6.9g, 44%).

Example 4

Preparation of Compound (4):

Compound (4):

The method of Example 2 was repeated except that in place of the product of Example 1 there was used the product of Example 3. Compound (4) was found to have adsorption maxima at 440 and 465nm.

Example 5

Preparation of Compound (5):

Compound (5) The method of Example 1 may be repeated except that in place of Intermediate (1) there is used Intermediate 2 (shown above) and in place of taurine there is used amino benzene having SO₂NHC₆H₄COaH groups at the 3- and 5-positions:

Example 6

Preparation of Compound (6):

Compound (6)

The method of Example 1 may be repeated except that in place of Intermediate (1) there is used Intermediate 2 (shown above) and in place of taurine there is used 3,5-disulpho aniline.

Example 7

Preparation of Compound (7):

Compound (7)

The method of Example 2 may be repeated except that in place of the product from Example 1 there is used a compound arising from performing the method of Example 1 using Intermediate (5) in place of Intermediate (1 ):

Intermediate (5) Example 8

Preparation of Compound (8):

Compound (8)

Example 1 may be repeated except that in place of Intermediate (1) there is used Intermediate (7):

Intermediate (7)

Example 9

Preparation of Compound (9):

Compound (8)

Example 2 may be repeated except that in place of the product from Example 1 there is used the product from Example 8.

Example 10

Preparation of Compound (10):

Compound (10) Example 6 may be repeated except that in place of Intermediate (2) there is used Intermediate (8):

Intermediate (8)

Inks

The inks described in Tables I and Il may be prepared wherein the compound referred to in the first column is the product from the above Example of the same number. Numbers quoted in the second column onwards refer to the number of parts of the relevant ingredient and all parts are by weight. The inks may be applied to paper by thermal or piezo ink jet printing. The following abbreviations are used in Table I and II:

PG = propylene glycol

DEG = diethylene glycol

NMP = N-methyl pyrollidone

DMK = dimethylketone

IPA = isopropanol

MEOH = methanol

2P = 2-pyrollidone

MIBK = methylisobutyl ketone

P12 = propane-1 ,2-diol

BDL = butane-2,3-diol

CET = cetyl ammonium bromide

PHO Na₂HPO₄

TBT = tertiary butanol

TDG = thiodiglycol TABLE I

CD

TABLE

O

Example 11

Inks may be prepared having the formulations described in US Patent Application Publication No. 2005/0076806 except that a compound of Formula (1 ) as defined in the first aspect of the present invention is used in place of the colorant described therein. Preferred inks of this type are described in Table 1 at pages 9 and 10 of US 2005/0076806. Especially preferred inks of this type are described below in Table III below and they may be prepared by mixing the components indicated therein. The inks may be applied to paper by thermal or piezo ink jet printing.

Table

Surfynol 465 RTM is an acetylenic glycol-based surfactant available from Air Products.

2P is 2-pyrollidone.

Example 12 Inks may be prepared having the formulations described above in Table III except that diethylene glycol mono n-butyl ether is used in place of triethylene glycol mono n-butyl ether. Still further inks may be prepared having the formulations described above in Table III except that N-methyl pyrollidone may be used in place of 2-pyrollidone. Example 13

Inks may be prepared as described in Japanese Patent Application No. 2005-047987 except that a compound of Formula (1 ) as defined in the first aspect of the present invention is used in place of the colorant used therein. Preferred inks of this type are described in claim 3 and Table 1 (at [0054]) of JP2005- 047987. In particular it is preferred that the inks contain 1 ,2-hexane diol.

Example 14

The black compositions A to D described in Table IV below may be prepared by mixing together the components in the amounts indicated. These black compositions may be used to prepare black ink jet printing inks, for example having an analogous formulation to the inks described in Table III above except that each of the black compositions described in Table IV is used instead of Compound 2 alone.

Table IV

Example 15

The yellow compositions E to I described in Table V below may be prepared by mixing together the components indicated. These yellow compositions may be used to prepare ink jet printing inks, for example having an analogous formulation to the inks described in Table III above except that each of the yellow compositions described in Table V is used instead of Compound 2 alone. Table V

Examples 16 to 19

Ink sets may be prepared wherein each ink has the formulation described for Ink A in Table III above, except that in the magenta, cyan and black inks Compound 2 was replaced by the colorant indicated in Table Vl below:

Table Vl

Cab-O-jet is a trade mark of Cabot corporation. Pro-Jet is a trade mark of Fujifilm Imaging Colorants Limited.

The ink sets described in Table Vl may be incorporated into a thermal ink jet printer and printed onto paper.

Claims

1. A process for printing an image on a substrate comprising applying to the substrate by means of an ink jet printer an ink comprising a water-soluble compound of Formula (1 ) which is free from fibre-reactive groups:

Formula (1 ) wherein: each R¹ and R² independently is a substituent other than H; m and n each independently has a value of 0 to 4;

(m+n) has a value of at least 1 ;

X and Y each independently is O, S, SO, SO₂ or -NR³-; and R³ is H or optionally substituted alkyl, aryl or heteroaryl.

2. A process according to claim 1 wherein m and n each independently has a value of 1 to 4.

3. A process according to claim 1 or 2 wherein X is O or S and at least one of the groups represented by R¹ is an electron donating group.

4. A process according to any one of the preceding claims wherein:

(i) at least one of the groups represented by R¹ and R² is a sulpho group; and

(ii) at least one of the groups represented by R¹ is Ci_-4-alkyl or Ci_-4- alkoxy.

5. A process according to any one of the preceding claims wherein Y is -NR³- wherein R³ is C-t_-4-alkyl carrying a sulpho and/or carboxy group.

6. A process according to any one of the preceding claims wherein m is 2, one of the groups represented by R¹ is C-i_-4-alkyl or Ci_-4-alkoxy and the other is sulpho, n is 1 , R² is a sulpho group, X is O and Y is -NR³- wherein R³ is Ci_₄-alkyl carrying a sulpho and/or carboxy group.

7. A water-soluble compound of Formula (1 ), as defined in claim 1 , which is free from fibre-reactive groups, wherein:

(i) at least one of the groups represented by R¹ and R² is a sulpho group; and (ii) at least one of the groups represented by R¹ is Ci_-4-alkyl or Ci_-4- alkoxy.

8. A compound according to claim 7 wherein Y is -NR³- wherein R³ is Ci_-4- alkyl carrying a sulpho and/or carboxy group.

9. A compound according to claim 7 or 8 wherein m is 2, one of the groups represented by R¹ is Ci_-4-alkyl or Ci_-4-alkoxy and the other is sulpho, n is 1 , R² is a sulpho group, X is O and Y is -NR³- wherein R³ is Ci_-4-alkyl carrying a sulpho and/or carboxy group.

10. A composition comprising: a) two or more water-soluble compounds of Formula (1 ) as defined in any one of the preceding claims; or b) one or more water-soluble compound of Formula (1 ) as defined in any one of the preceding claims and one or more colorants other than a water-soluble compound of Formula (1 ) as defined in any one of the preceding claims.

11. An ink for ink jet printing comprising: (a) a water-soluble compound of Formula (1 ) as defined any one of the preceding claims, or a composition according to claim 10; and (b) a liquid medium comprising water and an organic solvent.

12. A printed substrate obtained by a process according to any one of claims 1 to 6 or with an ink according to claim 11.

13. An ink jet printer cartridge comprising a chamber and ink, wherein the ink is present in the chamber and the ink is as defined in claim 11.

14. An ink jet printer containing an ink jet printer cartridge, wherein the ink jet printer cartridge is as defined in claim 13.