Compositions: coating or plastic – Coating or plastic compositions – Marking
Reexamination Certificate
2001-06-28
2004-03-30
Klemanski, Helene (Department: 1755)
Compositions: coating or plastic
Coating or plastic compositions
Marking
C534S836000, C427S466000, C428S032100
Reexamination Certificate
active
06712893
ABSTRACT:
This invention relates to compounds suitable for use as dyes, to inks and to their use in ink jet printing (“IJP”). 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.
There are many demanding performance requirements for dyes and inks used in IJP. For example they desirably provide sharp, non-feathered images having good water-fastness, light-fastness and optical density. The inks are often required to dry quickly when applied to a substrate to prevent smudging, but they should not form a crust over the tip of an ink jet nozzle because this will stop the printer from working. The inks should also be stable to storage over time without decomposing or forming a precipitate which could block the fine nozzle.
According to the present invention there is provided a compound of Formula (1) and salts thereof:
wherein:
m is 1, 2 or 3;
X is H or SO
3
H;
R
1
and R
2
are each independently selected from optionally substituted alkyl and optionally substituted alkoxy; and
R
4
and R
5
are each independently H, optionally substituted alkyl or optionally substituted aryl;
provided that:
(i) at least one of R
1
and R
2
carries an —OH group; and
(ii) when X is H at least one of R
1
and R
2
is optionally substituted alkyl.
In one preferred embodiment X is H and one of R
1
and R
2
is optionally substituted alkyl and the other is optionally substituted alkyl or optionally substituted alkoxy, provided that at least one of R
1
and R
2
carries an —OH group.
In a second embodiment X is SO
3
H and one of R
1
and R
2
is optionally substituted alkyl and the other is optionally substituted alkyl or optionally substituted alkoxy, provided that at least one of R
1
and R
2
carries an —OH group.
In a third embodiment X is SO
3
H and R
1
and R
2
are each independently optionally substituted alkoxy, provided that at least one of R
1
and R
2
carries an —OH group.
Preferably m is 1 or 2, more preferably 1.
When R
1
or R
2
is optionally substituted alkyl it is preferably optionally substituted C
1-4
-alkyl. When R
1
or R
2
is optionally substituted alkoxy it is preferably optionally substituted C
1-4
-alkoxy. The optional substituents which may be present on R
1
, R
2
, R
4
and R
5
are preferably selected from —NH
2
; halo, especially Cl, Br and F; ester, especially —CO
2
— C
1-4
-alkyl; —CO
2
H; —SO
3
H; —OR
3
; or —SR
3
; wherein each R
3
independently is H or C
1-4
-alkyl, provided that at least one of R
1
and R
2
carries an —OH group. Preferably both R
1
and R
2
carry an —OH group.
Preferably R
4
and R
5
are each independently H, optionally substituted C
1-4
-alkyl or optionally substituted phenyl, more preferably H, or C
1-4
-alkyl or phenyl carrying 1 or 2 groups selected from carboxy and sulpho. More preferably R
4
and R
5
are both H.
In an especially preferred embodiment, m is 1 or 2; and one of R
1
and R
2
is —OC
1-4
-alkyl—OH or —OC
1-4
-alkyl and the other is —C
1-4
-alkyl —OH or —C
1-4
-alkyl or m is 1 or 2; one of R
1
and R
2
is —OC
1-4
-alkyl—OH and the other is —OC
1-4
-alkyl or —O—C
1-4
-alkyl —OH; n is 0 or 1; and R
4
and R
5
are H.
The compounds of Formula (1) may be prepared by diazotising a compound of the Formula (2) to give a diazonium salt and coupling the resultant diazonium salt with a 1-hydroxy-3-sulpho-7-aminonaphthalene or a 1-hydroxy-3,6-disulpho-7-amino naphthalene:
wherein R
1
, R
2
and m are as hereinbefore defined.
The hydroxy group(s) on R
1
and/or R
2
may be protected during the diazotisation, for example using an acid labile or base labile protecting group. The acetoxy protecting group is particularly convenient and inexpensive.
The diazotisation is preferably performed at a temperature below 6° C., more preferably at a temperature in the range −10° C. to 5° C. Preferably the diazotisation is performed in water, preferably at a pH below 7. Dilute mineral acid, e.g. HCl or H
2
SO
4
, may be used to achieve the desired acidic conditions.
The compound of Formula (2) may be prepared by diazotising a carboxy aniline compound and coupling onto an aniline compound carrying the R
1
and R
2
groups at the 2- and 5- positions respectively.
Preferred salts are alkali metal salts (especially lithium, sodium and potassium salts), ammonium and substituted ammonium salts and mixtures thereof. Especially preferred salts are sodium, potassium and lithium salts, salts with ammonia and volatile amines and mixture thereof. The lithium salts have good solubility, forming particularly storage stable inks with low toxicity and tendency to block ink jet nozzles.
The compounds may be converted into a desired salt using known techniques. For example, an alkali metal salt of a compound may be converted into the ammonium or substituted ammonia salt by dissolving an alkali metal salt of the compound in water, acidifying with a mineral acid and adjusting the pH of the solution to pH 9 to 9.5 with ammonia or the amine and removing the alkali metal cations by dialysis or by use of an ion exchange resin.
Examples of amines which may be used to form such salts include methylamine, dimethylamine, trimethylamine, ethylamine, n-propylamine, iso-propylamine, n-butylamine, iso-butylamine, sec-butylamine, tert-butylamine, piperidine, pyridine, morpholine, allylamine, diethylamine, triethylamine, tetramethyl amine and mixtures thereof. It is not essential that the dyes are completely in the form of the ammonium salt or substituted ammonium salt and mixed alkali metal and either ammonium salt or substituted ammonium salt are effective, especially those in which at least 50% of the cations are ammonium or substituted ammonium ions.
Still further salts are those with the counter ions described in U.S. Pat. No. 5,830,265, claim 1, integer (b), which are included herein by reference thereto.
The compounds of Formula (1) may exist in tautomeric forms other than those shown in this specification. These tautomers are included within the scope of the present claims.
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 or a low melting point solid medium.
A preferred ink 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 or a low melting point solid medium; wherein all parts are by weight and 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 99.9 to 80, more preferably from 99.5 to 85, especially from 99 to 95 parts.
When the medium is a liquid, 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 which may be used to prepare 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 an organic solvent and an organic solvent free from water.
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.
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 C
1-6
-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 tetrahyd
Bradbury Roy
Mistry Prahalad Manibhai
Avecia Limited
Klemanski Helene
Pillsbury Wintthrop LLP
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