Ink additives
AssigneeAvecia Limited
InventorsAidan Joseph Lavery, Janette Watkinson, Mark Robert James
Life of this patent
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Abstract
The use of a polybasic acid and a volatile base, or a salt formed by the said acid and base, in an aqueous ink to increase the water-fastness of a water-soluble dye contained in the ink. Also claimed are novel aqueous inks containing an organic polybasic acid and a volatile base, a method of ink jet printing using the inks, a substrate printed with the inks and an ink jet printer cartridge containing the inks.
Claims31
An aqueous ink composition having a pH in the range of from 4 to 12 comprising:
- (a) an organic polybasic acid and a volatile base, or a salt formed by the said acid and base;
- (b) a water-soluble dye;
- and
- (c) an aqueous medium;
- wherein the volatile base, has a boiling point of less than 80° C.;
- and the organic polybasic acid is an aliphatic acid including 2 to 8 acid groups or an aromatic acid of Formula (1):
- Z—Xn (1)
- wherein
- Z is an aromatic group;
- each X independently is an acidic group;
- n is 1, 2, 3, or 4;
- and
- provided that:
- (i) the aqueous ink composition does not contain a polyamine or a phosphate;
- (ii) when the organic polybasic acid is oxalic acid, citric acid or phthalic acid the water-soluble dye has at least as many carboxy as sulpho groups;
- and
- (iii) when the volatile base is ammonia the organic polybasic acid has acid groups selected from carboxy, sulpho, phosphono, —SH and —COSH.
An aqueous ink composition having a pH in the range of from 4 to 12 comprising:
- (a) an organic polybasic acid and a volatile base, or a salt formed by the said acid and base;
- (b) a water-soluble dye having at least as many basic nitrogen groups as sulpho groups;
- and
- (c) an aqueous medium;
- wherein the volatile base has a boiling point of less than 80° C.;
- and the organic polybasic acid is an aliphatic acid with 2 to 8 acid groups or an aromatic acid of the Formula (1):
- Z—Xn (1)
- wherein;
- Z is an aromatic group;
- each X independently is an acidic group;
- n is 1,2,3, or 4;
- and
- provided that:
- (i) the aqueous ink composition does not contain a polyamine or a phosphate;
- (ii) when the organic polybasic acid is oxalic acid, citric acid or phthalic acid the water-soluble dye has at least as many carboxy as sulpho groups;
- and
- (iii) when the volatile base is ammonia the organic polybasic acid has acid groups selected from carboxy, sulpho, phosphono, —SH and —COSH.
An aqueous ink composition having a pH in the range of from 4 to 12 comprising:
- (a) an organic polybasic acid and a volatile base, or a salt formed by the said acid and base;
- (b) a water-soluble dye;
- and
- (c) an aqueous medium;
- wherein the volatile base has a boiling point of less than 80° C.;
- and the organic polybasic acid is an aromatic polybasic acid of Formula (1):
- Z—Xn (1)
- wherein:
- Z is an aromatic group:
- each X independently is selected from carboxy, sulpho, phosphono, —SH and —COSH;
- n is 2, 3, or 4;
- provided that:
- (i) the aqueous ink composition does not contain a polyamine or a phosphate;
- (ii) when the organic polybasic acid is oxalic acid, citric acid or phthalic acid the water-soluble dye has at least as many carboxy as sulpho groups;
- and
- (iii) when the volatile base is ammonia the organic polybasic acid has acid groups selected from carboxy, sulpho, phosphono, —SH and —COSH.
An aqueous ink composition having a pH in the range of from 4 to 12 comprising:
- (a) an organic polybasic acid and a volatile base, or a salt formed by the said acid and base;
- (b) a water-soluble dye;
- and
- (c) an aqueous medium;
- wherein the volatile base has a boiling point of less than 80° C.;
- and the organic polybasic acid is an aliphatic polybasic acid containing up to 20 atoms, and
- provided that:
- (i) the aqueous ink composition does not contain a polyamine or a phosphate;
- (ii) when the organic polybasic acid is oxalic acid, citric acid or phthalic acid the water-soluble dye has at least as many carboxy as sulpho groups;
- and
- (iii) when the volatile base is ammonia the organic polybasic acid has acid groups selected from carboxy, sulpho, phosphono, —SH and —COSH.
A method for increasing the water-fastness of a water-soluble dye comprising addition of an effective amount of a polybasic acid and a volatile base, or a salt formed by the said acid and base, to an aqueous ink containing the water-soluble dye wherein the volatile base has a boiling point of less than 80° C.;
- and the organic polybasic acid is an aliphatic acid with 2 to 8 acid groups or an aromatic acid of the Formula (1):
- Z—Xn (1)
- wherein:
- Z is an aromatic group;
- each X independently is an acidic group;
- and
- n is 1, 2, 3, or 4.
In an aqueous ink composition adapted for use in an ink jet printing process, the improvement comprising a polybasic acid and a volatile base, or a salt formed by the said acid and base, added to said aqueous ink composition to increase the water fastness of a water-soluble dye contained in the ink and where the polybasic acid contains one or more acid groups selected from the group consisting of carboxy, sulpho, monobasic phosphate ester, a monobasic phosphonic ester, —COSH and thiol.
An aqueous ink composition adapted for use in an ink jet printing process where an improvement comprises a polybasic acid, wherein said polybasic acid is an aliphatic polybasic acid containing up to 20 carbon atoms;
- and a volatile base, or a salt formed by the said acid and base, added to said aqueous ink composition to increase the water fastness of a water-soluble dye contained in the ink.
An aqueous ink composition adapted for use in an ink jet printing process, where an improvement comprises a polybasic acid and a volatile base, or a salt formed by the said acid and base, added to said aqueous ink composition to increase the water fastness of a water-soluble dye contained in the ink wherein the aliphatic polybasic acid is a compound of the Formula (2):
- HOOC—W—COOH (2)
- wherein W is an optionally substituted, optionally interrupted alkylene, alkenylene or alkynylene group.
Dependencies are inferred from the claim text.