Black ink for ink-jet recording
First Claim
Patent Images
1. A black ink for ink-jet recording, comprising a dye dissolved and/or dispersed in an aqueous medium, wherein the dye has a λ
- max of 500 to 700 nm and a half value width of 100 nm or more in an absorption spectrum of a dilute solution normalized to an absorbance of 1.0 and is a dye represented by the following general formula (1);
wherein A, B and C each independently represent an aromatic or heterocyclic group, which are substituted or unsubstituted provided that two or more of A, B and C is a substituted or unsubstituted, unsaturated heterocyclic group;
m is 1 or 2;
n is 1 or 2,wherein the black ink has;
a transition metal ion content of 0.1 mmol/l or less; and
a forced fading rate constant kvis of 5.0×
10−
2 [hour−
1] or less, in which the forced fading rate constant kvis is decided by printing a black square symbol of JIS code 2223 in 48-point by using the black ink, measuring a reflection density Dvis of the printed symbol through a status A filter to obtain an initial density, forcedly fading the printed symbol by an ozone fading tester capable of continuously generating 5 ppm of ozone, and determining the time taken until the reflection density Dvis reaches 80% of the initial density.
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Abstract
A black ink for ink-jet recording, which is excellent in durability of image (including durability of image quality) and discharging property, obtained by dissolving and/or dispersing at least one black azo dye having a particular property or structure in an aqueous medium, wherein a transition metal ion content of the black ink is 0.1 mmol/l or less.
31 Citations
23 Claims
-
1. A black ink for ink-jet recording, comprising a dye dissolved and/or dispersed in an aqueous medium, wherein the dye has a λ
- max of 500 to 700 nm and a half value width of 100 nm or more in an absorption spectrum of a dilute solution normalized to an absorbance of 1.0 and is a dye represented by the following general formula (1);
wherein A, B and C each independently represent an aromatic or heterocyclic group, which are substituted or unsubstituted provided that two or more of A, B and C is a substituted or unsubstituted, unsaturated heterocyclic group;
m is 1 or 2;
n is 1 or 2,wherein the black ink has;
a transition metal ion content of 0.1 mmol/l or less; and
a forced fading rate constant kvis of 5.0×
10−
2 [hour−
1] or less, in which the forced fading rate constant kvis is decided by printing a black square symbol of JIS code 2223 in 48-point by using the black ink, measuring a reflection density Dvis of the printed symbol through a status A filter to obtain an initial density, forcedly fading the printed symbol by an ozone fading tester capable of continuously generating 5 ppm of ozone, and determining the time taken until the reflection density Dvis reaches 80% of the initial density. - View Dependent Claims (6, 7, 12, 16, 17)
- max of 500 to 700 nm and a half value width of 100 nm or more in an absorption spectrum of a dilute solution normalized to an absorbance of 1.0 and is a dye represented by the following general formula (1);
-
2. A black ink for ink-jet recording, comprising a first dye and a second dye dissolved and/or dispersed in an aqueous medium, in which the first dye has a λ
- max of 500 to 700 nm and a half value width of 100 nm or more in an absorption spectrum of a dilute solution normalized to an absorbance of 1.0 and the second dye has a λ
max of 350 to 500 nm in an absorption spectrum of an aqueous solution, wherein the black ink has a transition metal ion content of 0.1 mmol/l or less, and wherein the first dye is a dye represented by the following general formula (1);
wherein A, B and C each independently represent an aromatic or heterocyclic group, which are substituted or unsubstituted;
m is 1 or 2;
n is 1 or 2 and two or more of A, B and C is a substituted or unsubstituted, unsaturated heterocyclic group. - View Dependent Claims (8, 9, 13, 18, 19)
- max of 500 to 700 nm and a half value width of 100 nm or more in an absorption spectrum of a dilute solution normalized to an absorbance of 1.0 and the second dye has a λ
-
3. A black ink for ink-jet recording, comprising a dye dissolved and/or dispersed in an aqueous medium, wherein the dye has a λ
- max of 500 to 700 nm and a half value width of 100 nm or more in an absorption spectrum of a dilute solution normalized to an absorbance of 1.0 and is a dye represented by the following general formula (1);
wherein A, B and C each independently represent an aromatic or heterocyclic group, which are substituted or unsubstituted provided that two or more of A, B and C is a substituted or unsubstituted, unsaturated heterocyclic group;
m is 1 or 2;
n is 1 or 2,wherein the black ink has a transition metal ion content of 0.1 mmol/l or less; and
a ratio R of 1.2 or less, in which the ratio R is defined as a ratio of a maximum value to a minimum value of a forced fading rate constants kR, kG and kB that are decided by printing a black square symbol of JIS code 2223 in 48-point by using the black ink, measuring reflection densities DR, DG and DB of the printed symbol with respect to 3 colors of C (cyan), M (magenta) and Y (yellow) through a status A filter to obtain initial densities, respectively, forcedly fading the printed symbol by an ozone fading tester capable of continuously generating 5 ppm of ozone, and determining the times taken until the reflection densities DR, DG and DB reach 80% of the initial densities, respectively. - View Dependent Claims (10, 11, 14, 20, 21)
- max of 500 to 700 nm and a half value width of 100 nm or more in an absorption spectrum of a dilute solution normalized to an absorbance of 1.0 and is a dye represented by the following general formula (1);
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4. A black ink for ink-jet recording, comprising a dye dissolved and/or dispersed in an aqueous medium, wherein the dye has a λ
- max of 500 to 700 nm and a half value width of 100 nm or more in an absorption spectrum of a dilute solution normalized to an absorbance of 1.0 and is a dye represented by the following general formula (1);
wherein A, B and C each independently represent an aromatic or heterocyclic group, which are substituted or unsubstituted provided that two or more of A, B and C is a substituted or unsubstituted, unsaturated heterocyclic group;
m is 1 or 2;
n is 1 or 2,wherein the black ink has a transition metal ion content of 0.1 mmol/l or less, and the black ink comprises a dye having an oxidation potential of more than 1.0 V (vs SCE). - View Dependent Claims (5, 15, 22, 23)
- max of 500 to 700 nm and a half value width of 100 nm or more in an absorption spectrum of a dilute solution normalized to an absorbance of 1.0 and is a dye represented by the following general formula (1);
Specification