BRADBURY ROY
BRADBURY LYNN PATRICIA (GB)
WRIGHT GAVIN (GB)
| EP0063387A1 | 1982-10-27 | |||
| US4097450A | 1978-06-27 | |||
| EP0604181A1 | 1994-06-29 |
CLAIMS
1. A compound of Formula (1 ) and salts thereof:
Formula (1 ) wherein: each R i1 : i-ndependently is a substituent other than hydrogen; n has a value of 0 to 6; and one of R 2 and R 3 is hydrogen and the other is a group of the formula
-N=N-A wherein A is optionally substituted aryl or heteroaryl; with the proviso that the compound of Formula (1) has at least one water- solubilising group.
2. A compound according to claim 1 wherein A is optionally substituted naphthyl or optionally substituted phenyl.
3. A compound according to claim 1 or claim 2 wherein the optional substituents which may be present on A or represented by R 1 are each independently selected from optionally substituted alkyl, alkoxy, amine, amide, ester, ketone, ether and thioether groups and from halo, acid, -CF 3 , -CN, -NO 2 and -OH groups.
4. A compound according to any one of the preceding claims wherein n has a value of 1 , 2, 3 or 4.
5. A compound according to any one of the preceding claims wherein R 3 is hydrogen.
6. An ink comprising a liquid medium and a compound of Formula (1 ) or salt thereof according to any one of the preceding claims.
7. An ink according to claim 6 wherein the compound of Formula (1 ) or salt thereof is fully dissolved in the ink.
8. An ink according to claim 6 or 7 comprising:
(a) from 0.01 to 30 parts of the compound of Formula (1 ) or salt thereof; and
(b) from 70 to 99.99 parts of a liquid medium; wherein all parts are by weight and the number of parts of (a) + (b) = 100.
9. A process for printing an image on a substrate which comprises applying to the substrate an ink comprising a compound of Formula (1) or salt thereof according to any one of claims 1 to 5.
10. A process according to claim 9 wherein the ink is as defined in any one of claims 6 to 8.
11. A process according to claim 9 or 10 wherein the ink is applied by means of an ink jet printer.
12. A substrate printed with a compound of Formula (1) or salt thereof according to any one of claims 1 to 5.
13. A substrate according to claim 12 printed with an ink according to any one of claims 5 to 17.
14. An ink jet printer cartridge comprising a chamber and ink, wherein the ink is present in the chamber and the ink comprises a compound of Formula (1) or salt thereof according any one of claims 1 to 5. |
Colorants
This invention relates to compounds, to inks containing the compounds and to their uses in ink jet printing ("IJP"). UP 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.
There are many demanding performance requirements compounds used in IJP and the inksέεontaining them. For example, the inks desirably provide sharp, non-feathered images having high optical density, good light-fastness, good ozone fastness and a bright colour. The inks are often required to dry quickly when applied to a substrate to prevent smudging, but they should not dry so quickly as to form a crust over the tip of ink jet nozzles and thereby reduce the printer's performance. The inks should also be stable to storage over time without decomposing or forming a precipitate that could block the fine nozzles.
According to a first aspect of the present invention there is provided a compound of Formula (1 ) and salts thereof:
-N=N-A wherein A is optionally substituted aryl or heteroaryl; with the proviso that the compound of Formula (1 ) has at least one water- solubilising group.
Preferably n has a value of 1 , 2, 3 or 4, more preferably 1 or 2.
Preferably R 3 is hydrogen.
The preferred water-solubilising groups are cationic groups or, more preferably, acid groups, especially carboxy, thiocarboxy, sulpho and phosphate groups. Preferably the compound of Formula (1) has at least two water- solubilising groups, more preferably 2, 3 or 4 water-solubilising groups. Preferred water-solubilising groups are selected from carboxy, phosphate and sulpho groups.
In one embodiment the compound of Formula (1 ) has at least one carboxy group.
In another embodiment the compound of Formula (1 ) has at least as many carboxy groups as sulpho groups.
When A is optionally substituted aryl it is preferably optionally substituted polycyclic or monocyclic aryl. Preferred polycyclic aryl groups include naphthyl, anthracyl and pyrenyl groups. Preferred monocyclic aryl groups are phenyl groups. Preferably A is optionally substituted naphthyl or phenyl.
The optional substituents which may be present on A or represented by R 1 are preferably each independently selected from optionally substituted alkyl, alkoxy, amine, amide, ester, ketone, ether and thioether groups and from halo, acid (especially carboxy, phosphato and sulpho groups), -CF 3 , -CN, -NO 2 and -OH groups.
Preferred optionally substituted amine groups are of the formula -NR 4 R 5 wherein R 4 and R 5 are each independently H or optionally substituted alkyl, aryl or heteroaryl, or R 4 and R 5 together with the nitrogen atom to which they are attached form an optionally substituted 5- or 6- membered ring (e.g. a piperidine, pyrrolidone, pyridine, piperizine or morpholine ring).
Preferred optionally substituted amide groups are of the formu)a -NHC(O)NR 4 R 5 , -C(O)NR 4 R 5 , -S(O) 2 NR 4 R 5 or -NHC(O)R 5 , wherein R 4 and R 5 are as hereinbefore defined.
Preferred optionally substituted ester groups are of the formula -C(O)OR 5 Or -S(O) 2 OR 5 , wherein R 5 is as hereinbefore defined in -NHC(O)R 5 the R 5 group is H or optionally substituted alkyl, aryl or heteroaryl.
Preferred optionally substituted ketone groups are of the formula -C(O)R 5 or -S(O) 2 R 5 , wherein R 5 is as hereinbefore defined.
Preferred acid groups are sulpho and carboxy groups.
Preferred optionally substituted ether and thioether groups are respectively of the formula -OR 5 or -SR 5 , wherein R 5 is optionally substituted alkyl, aryl or heteroaryl.
Preferred halo groups are Cl, F, Br and I.
Preferred optionally substituted alkyl groups include C-i-a-alkyl, more preferably Ci -4 -alkyl, in each case optionally carrying a substituent, preferably a substituent selected from halo, carboxy, alkoxy, hydroxy and sulpho. Examples of optionally substituted alkyl groups include methyl, ethyl, n-butyl, sec-butyl, trifluoromethyl, hydroxyethyl, sulphopropyl and carboxyethyl.
Preferred optionally substituted alkoxy groups include C-i -8 -alkoxy, more preferably C-ι- 4 -alkoxy, in each case optionally carrying a substituent, preferably a substituent selected from hydroxy, sulpho, halogen and carboxy. Examples of
optionally substituted alkoxy groups include methoxy, ethoxy, butoxy, carboxypropoxy, carboxyethoxy, hydroxyethoxy and chloroethoxy.
When R 4 and R 5 together with the nitrogen atom to which they are attached form an optionally substituted 5- or 6- membered ring, the optional substituents are preferably any of those listed above for the group represented by A.
Preferably -A has from 1 to 5 substituents, more preferably 1 or 2 substituents, preferably selected from sulpho and carboxy. In one embodiment -A carries two sulpho substituents and is free from further substituents.
In one embodiment all of the water-solubilising groups present in the compound of Formula (1) are attached to -A.
Preferably each R 1 independently is optionally substituted alkyl or optionally substituted aryl. Preferred optionally substituted alkyl and optionally substituted aryl groups are as mentioned above. More preferably each R 1 independently is Ci-4-alkyl.
The compounds of Formula (1) exist in tautomeric forms other than those shown in this specification and such tautomers are included within the scope of the present invention.
Formula (1 ) encompasses the compounds in the free acid and salt forms. Preferred salt forms are water-soluble, for example alkali metal salts (especially lithium, sodium, potassium), ammonium, substituted ammonium and mixed salts thereof.
Preferred ammonium and substituted ammounium salts are ammonium and alkyl or aryl substituted ammonium (e.g. ammonium, alkanolammonium, pyridinium, piperidinium and morpholinium).
It is especially preferred that the compounds of Formula (1 ) are in the form of a sodium, lithium, potassium or ammonium salt or a mixture thereof.
Preferably the compound of Formula (1 ) is a dye, more preferably a water- soluble dye.
Preferably the compound of Formula (1 ) is yellow, orange or brown. The compounds of the present invention are useful for preparing inks which, when printed, exhibit useful properties with respect to ozone fastness, optical density and light fastness.
The compounds of Formula (1 ) may be prepared by, for example, reacting a compound of Formula (2) with a compound of Formula (3):
Formula (2) Formula (3)
wherein R 1 , R 2 , R 3 and n are as hereinbefore defined.
Preferably the reaction comprises heating a mixture comprising the compounds of Formula (2) and Formula (3), preferably at a temperature of 70 to 100 0 C. The time for the reaction depends to some extent on the temperature and the identity of R 1 , R 2 , R 3 and n, but typically a time of 1 to 10 hours is sufficient.
The compounds of Formula (3) may be prepared by diazotising a compound of the Formula A-NH 2 to give a diazonium salt and coupling the resultant diazonium salt with 1 ,2-diaminobenzene, wherein A is as hereinbefore defined.
The diazotisation is preferably performed at a temperature below 20 0 C, more preferably at a temperature from 0°C to 5 0 C. Preferably, the diazotisation is performed in a liquid comprising water, preferably having a very acidic pH (below 3). Mineral acids (e.g. HCI or H 2 SO 4 or mixtures thereof) are typically used to achieve such an acidic pH.
The coupling reaction is preferably performed at a temperature of from 0 to 5 0 C, typically for a period of 1 to 6 hrs. It is often desirable to add a buffer (e.g. sodium acetate) to adjust the pH to 4 to 5. The coupling reaction is preferably performed in a liquid comprising water. The coupling reaction is preferably continued for a further period of 16 hours at 25 0 C.
As mentioned above, the water-solubilising groups in the compound of Formula (1) may be acid groups in the form of a free acid or a salt. The salts may be prepared by, for example, using precursors which are in the form of a salt, or the compound of Formula (1) in the form of the free-acid may be neutralised with a base (e.g. sodium, lithium, or potassium hydroxide, ammonia, a substituted ammonium compound or an alkanolamine). It is also possible to exchange the cation in the salt, for example using a cation exchange resins.
According to a second aspect of the present invention there is provided an ink comprising a compound of Formula (1 ) or salt thereof and a liquid medium.
The liquid medium preferably comprises water and an organic solvent.
A preferred ink according to the second aspect of the present invention comprises:
(a) from 0.01 to 30 parts of a compound of Formula (1) or salt thereof; and
(b) from 70 to 99.99 parts of a liquid medium; wherein all parts are by weight and the number of parts of (a) + (b) = 100.
The number of parts by weight of component (a) is preferably from 0.01 to 25, 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 75, 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.
Preferably the compound of Formula (1) or salt thereof is completely dissolved in the liquid medium. Preferably, the compound of Formula (1) and salts thereof have a solubility in the liquid medium at 20°C of at least 10% by weight. This allows the preparation of ink concentrates which may be used to prepare more dilute inks.
When the liquid medium comprises a mixture of water and an 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.
Preferably 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, 1 ,2-hexanediol, 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- M -alkyl 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.
In one embodiment the ink contains a glycol monoether and a 1 ,2-alkane diol in a weight ratio of 1 :2 to 2:1 and optionally a pigment (e.g. a yellow pigment).
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- 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.
Examples of further suitable liquid media comprising a mixture of water and one or more organic solvents are described in US 4,963,189, US 4,703,113, US 4,626,284 and EP 4,251 ,5OA incorporated herein by reference thereto.
The inks according to the second aspect of the present invention may comprise one or more compounds of Formula (1 ) or salts thereof.
The inks according to the second aspect of the present invention may comprise one or more additional colorants other than a compound of Formula (1) or salt thereof. The additional colorant may be a pigment but is preferably a dye.
When the additional colorant is a pigment the pigment is preferably a yellow pigment, examples of which include yellow monoazo pigments such as C.I. Pigment Yellow 1 , 2, 3, 10, 60, 73, 74, 75, 120, 151 and 175; disazo pigments such as C.I. Pigment Yellow 12, 13, 14, 16, 17, 81 , 83, 93, 95, 126, 128, 174 and 180; isoindolinone pigments such as C.I. Pigment Yellow 109, 110, 139 and 185; anthraquinone pigments such as C.I. Pigment Yellow 23, 108 and 147; and quinophthalone pigments such as C.I. Pigment Yellow 138.
When the additional colorant is a dye the dye is preferably a yellow dye mentioned in the Colour Index International, especially C.I. Direct Yellow 1 , 2, 4, 8, 11 , 12, 26, 27, 28, 33, 34, 41 , 44, 48, 86, 87, 88, 132, 135, 142 or 144; and/or C.I. Acid Yellow 1 , 3, 4, 7, 11 , 12, 13, 14, 19, 23, 25, 34, 38, 41 , 42, 44, 53, 55, 61 , 71 , 76 or 79. Further additional dyes are described in US patent No. 6,878,196 (especially dyes 1 , 6B, 7B and 22B which are incorporated herein by reference thereto) and US patent No. 6,855,195.
Typically the compound of Formula (1) and the additional colorant are included in the ink in a weight ratio of 1 :2 to 2:1.
The ink may contain additives of the kind used in ink jet printing inks, for example viscosity and surface tension modifiers, corrosion inhibitors, biocides (e.g. Proxel™ Biocide), kogation reducing additives, anti-cockle agents to reduce paper curling and surfactants (e.g. Olefin E 1010) 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 is preferably less than 5OmPa. s, more preferably less that 2OmPa. s and especially less than δmPa.s. The viscosity is preferably measured at a temperature of 25 0 C.
Thermal ink jet printers are particularly sensitive to minor impurities in the ink. Such impurities may corrode or form a deposit on the resistors used to boil and thereby fire ink from the printheads resulting in poor print quality.
Thus one embodiment of the second aspect of the present invention provides an ink jet printing ink having a concentration of halide ions of less than 500 parts per million and 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 in total of divalent and trivalent metals. Parts per million refer to parts by weight of the relevant ions or metals relative to the total weight of the ink. Any suitable means to remove chloride ions and/or di and trivalent metals may be employed, e.g. ion exchange and ultra-filtration.
The inks of the present invention preferably form the yellow ink of an ink set comprising a yellow, magenta, cyan and black ink. Typically, in such an ink set the magenta ink contains, for example, C.I. Acid Red 52 and/or Pro-Jet™ Fast Magenta 2, the cyan ink contains, for example, C.I. Direct Blue 86, 199 and/or Pro-Jet™ Fast Cyan 2 and the black ink contains, for example, C.I. Direct Black 199 and/or Pro- Jet™ Fast Black 2 (Pro-Jet is a trade mark of Avecia InkJet Limited).
According to a third aspect of the present invention there is provided a process for printing an image on a substrate which comprises applying to the substrate an ink comprising a compound of Formula (1 ) or salt thereof. Preferably, the ink is as defined in the second aspect of the present invention.
Preferably the ink is applied to the substrate by means of an ink jet printer.
According to a fourth aspect of the present invention there is provided a substrate (preferably paper, an overhead projector slide or a textile material) printed with a compound of Formula (1) or salt thereof according to the first aspect of the present invention. Preferably the ink is as defined in the second aspect of the present invention.
According to a fifth 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 comprises a compound of Formula (1 ) or salt thereof according to the first aspect of the present invention. Preferably the ink is as defined in the second 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 )
Compound 1 was prepared as follows:
Stage (a) Preparation of Intermediate (a)
Intermediate (1a)
5-Aminonbenzene-1 ,3-disulfonic acid (11Og, 0.43mol) was dissolved in water (800ml) at a pH of 7 by the addition of 2N sodium hydroxide solution followed by the addition of sodium nitrite (32.6g, 0.48mol). The resultant solution was added dropwise to a mixture of concentrated hydrochloric acid (120ml) and water (200ml) at a temperature of from 0 to 5 0 C to produce a diazonium salt.
The diazonium salt was stirred for 1 hour at a temperature of 0 to 5 0 C and then any excess nitrous acid was destroyed by adding sulfamic acid. 1 ,2- Diaminobenzene (46.5g, 0.43mol) was added at a temperature from 0 to 5 0 C and the pH was adjusted to 4-5 by adding sodium acetate. The resultant mixture was stirred for 4 hours at a temperature of 0 to 5°C and then at 2O 0 C for a further 16 hours.
The resultant product was precipitated by the addition of salt, collected by filtration and dried in an oven at 6O 0 C to give Intermediate (a).
Stage (b) Preparation of Compound 1
A mixture of the product from stage (a) (3.7g, 0.01 mol) and naphthalic anhydride (2.Og, 0.01 mol) in ethanol (100ml) was stirred under reflux for 1 hour. Water (50ml) was added to the reaction mixture followed by the dropwise addition
of a solution of sodium hydrosulfite (3.1g, 0.03mol) in water (50ml). The reaction mixture was stirred under reflux for 4 hours and then allowed to cool, the product was collected by filtration, the precipitate dissolved in water (500ml) and purified by dialysis in membrane tubing to conductivity of less than 50μs. After evaporation of the water at 6O 0 C, Compound (1 ) was obtained.
Examples 2 to 7
The method of Example 1 , stages (a) and (b), may be repeated except that in place of naphthalic anhydride there is used an equimolar amount of the anhydride indicated in the second column of Table A below:
Table A:
Examples 8 to 35
The methods of Examples 1 to 7 may be repeated except that in stage (a), in place of 5-aminonbenzene-1 ,3-disulfonic acid there is used an equimolar amount of the amine indicated in the second column of Table B below:
Table B:
Inks
The inks described in Tables I and Il may be prepared comprising Compound (1) or for that matter any of the compounds of Formula (1) or salts thereof. Numbers quoted in the second column onwards refer to the number of parts of the relevant components and all parts are by weight. The inks may be applied to paper by, for example, thermal or piezo ink jet printing or using a Silverbrook ink jet printer.
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
GET = cetyl ammonium bromide
PHO Na 2 HPO 4
TBT = tertiary butanol
TDG = thiodiglycol
TABLE I
TABLE
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