Aqueous ink composition and ink-jet printing method using the same
AssigneeRicoh Company, Ltd.
InventorsKiyofumi Nagai, Kakuji Murakami
Life of this patent
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Abstract
ASn aqueous ink composition composed of water, a lubricant, a coloring agent dispersed or dissolved in water, and a compound of formula (I): R--O(CH.sub.2 CH.sub.2 O).sub.m CH.sub.2 COOM (I) wherein R is an alkyl group having 6 to 14 carbon atoms which may be branched; M is a cation selected from the consisting of alkali metal ion, quaternary ammonium cation, quaternary phosphonium cation, and alkanol amine cation; and m is an integer of 3 to 12. Further, an ink-jet printing method of recording color images is disclosed, which includes the step of ejecting the above-mentioned aqueous ink composition from nozzles onto an image-receiving medium with a Stockigt sizing degree of 3 seconds or more as defined in the JIS-P-8122.
Claims18
An aqueous ink composition comprising water, a lubricant, a coloring agent dispersed or dissolved in water, and a compound of formula (I):
- R--O(CH.sub.2 CH.sub.2 O).sub.m CH.sub.2 COOM (I)
- wherein R is an alkyl group having 6 to 14 carbon atoms;
- M is a cation selected from the group consisting of alkali metal ion, quaternary ammonium cation, quaternary phosphonium cation, and alkanol amine cation;
- and m is an integer of 3 to 12, where compound (I) is present in the ink composition in amount to decrease the surface tension of the ink to 50 mJ/m.sup.2 or less.
An aqueous ink composition comprising water, a lubricant, a coloring agent dispersed or dissolved in water, an anion of formula (I-1):
- R--O(CH.sub.2 CH.sub.2 O).sub.m CH.sub.2 COO.sup.- (I- 1)
- wherein R is an alkyl group having 6 to 14 carbon atoms, and m is an integer of 3 to 12;
- at least one counter cation selected from the group consisting of alkali metal ion, quaternary ammonium cation, quaternary phosphonium cation, and alkanol amine cation;
- and a compound of formula (I-2):
- R--O(CH.sub.2 CH.sub.2 O).sub.m CH.sub.2 COOH (I-2)
- wherein R is an alkyl group having 6 to 14 carbon atoms, and m is an integer of 3 to 12, said ink composition having a pH of 6 or more, where anion (I-1) and its counter cation and compound (I-2) are present in the ink composition in amount to decrease the surface tension of the ink to 50 mJ/m.sup.2 or less.
A method of recording color images on an image-receiving medium, comprising the step of ejecting an aqueous ink composition in the form of droplets from nozzles onto an image-receiving medium with a Stockigt size degree of 3 seconds or more as defined in the Japanese Industrial Standards P-8122, said aqueous ink composition comprising water, a lubricant, a coloring agent dispersed or dissolved in water, and a compound of formula (I):
- R--O(CH.sub.2 CH.sub.2 O).sub.m CH.sub.2 COOM (I)
- wherein R is an alkyl group having 6 to 14 carbon atoms;
- M is a cation selected from the group consisting of alkali metal ion, quaternary ammonium cation, quaternary phosphonium cation, and alkanol amine cation;
- and m is an integer of 3 to 12, where compound (I) is present in the ink composition in amount to decrease the surface tension of the ink to 50 mJ/m.sup.2 or less.
A method of recording color images on an image-receiving medium, comprising the step of ejecting an aqueous ink composition in the form of droplets from nozzles onto an image-receiving medium with a Stockigt size degree of 3 seconds or more as defined in the Japanese Industrial Standards P-8122, said aqueous ink composition comprising water, a lubricant, a coloring agent dispersed or dissolved in water, an anion of formula (I-1):
- R--O(C.sub.2 CH.sub.2 O).sub.m CH.sub.2 COO.sup.- (I- 1)
- wherein R is an alkyl group having 6 to 14 carbon atoms, and m is an integer of 3 to 12;
- at least one counter cation selected from the group consisting of alkali metal ion, quaternary ammonium cation, quaternary phosphonium cation, and alkanol amine cation;
- and a compound of formula (I-2)
- R--O(CH.sub.2 CH.sub.2 O).sub.m CH.sub.2 COOH (I-2)
- wherein R is an alkyl group having 6 to 14 carbon atoms, and m is an integer of 3 to 12, where anion (I-1) and its counter cation and compound (I-2) are present in the ink composition in amount to decrease the surface tension of the ink to 50 mJ/m.sup.2 or less.
An aqueous ink composition comprising water, a lubricant, a coloring agent dispersed or dissolved in water, and a compound of formula (I):
- R--O(CH.sub.2 CH.sub.2 O).sub.m CH.sub.2 COOM (I)
- wherein R is an alkyl group having 6 to 14 carbon atoms;
- M is a cation selected from the group consisting of alkali metal ion, quaternary ammonium cation, quaternary phosphonium cation, and alkanol amine cation;
- and m is an integer of 3 to 12, the amount of the compound of formula (I) in the ink composition being 0.05 to 10 wt. % of the weight of the ink composition.
An aqueous ink composition comprising water, a lubricant, a coloring agent dispersed or dissolved in water, an anion of formula (I-1):
- R--O(CH.sub.2 CH.sub.2 O).sub.m CH.sub.2 COO.sup.- (I- 1)
- wherein R is an alkyl group having 6 to 14 carbon atoms, and m is an integer of 3 to 12;
- at least one counter cation selected from the group consisting of alkali metal ion, quaternary ammonium cation, quaternary phosphonium cation, and alkanol amine cation;
- and a compound of formula (I-2):
- R--O(CH.sub.2 CH.sub.2 O).sub.m CH.sub.2 COOH (I-2)
- wherein R is an alkyl group having 6 to 14 carbon atoms, and m is an integer of 3 to 12, said ink composition having a pH of 6 or more, the amount of anion (I-1) present in the aqueous ink composition being at least 30% of the number of mols of the salt of compound (I-1) and its counter cation, the salt being of formula (I) and being present in amount which is 0.05 to 10 wt. % of the weight of the ink composition, where formula (I) is
- R--O(CH.sub.2 CH.sub.2 --O).sub.m CH.sub.2 OOM
- and M is said counter cation.
Dependencies are inferred from the claim text.