# US 7,465,344 B2 · Ink for ink jet recording comprising print density improver, print density improver and method for improving print density

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- Number: US 7,465,344 B2
- Document ID: US7465344B2
- Status: Granted
- Kind: B2
- Application number: 11/392,487
- Filed: 2006-03-30
- Published: 2006-12-07
- Granted: 2008-12-16
- Earliest claimed: 2005-03-31
- Assignees: FUJIFILM Corporation
- Inventors: Tomohiro Chino; Takashi Ozawa
- Web page: https://patentgrep.com/patent/US7465344B2

## CPC

- C09B 5/14: Benz-azabenzanthrones (anthrapyridones)
- C09B 33/12: in which the coupling component is a heterocyclic compound
- C09B 33/22: Trisazo dyes of the type A->B->K<-C
- C09B 35/50: Tetrazo dyes
- C09B 47/20: Obtaining compounds having sulfur atoms directly bound to the phthalocyanine skeleton
- C09B 47/26: Amide radicals
- C09B 67/0055: {Mixtures of two or more disazo dyes}
- C09D 11/328: characterised by dyes
- C09D 11/38: characterised by non-macromolecular additives other than solvents, pigments or dyes
- C09B: ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES {, e.g. PIGMENTS}; MORDANTS; LAKES (fermentation or enzyme using processes to synthesise a desired chemical compound C12P)
- C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D)

## Abstract

An aqueous ink for ink jet recording, which comprises: at least one dye; and at least one of a compound having at least one phosphonic acid group and at least one carboxyl group and a compound having at least two phosphonic acid groups as a print density improver(s), a print density improver, and a method for enhancing print density involving the use of the aforementioned print density improver.

## Claims

### Claim 1

An aqueous ink for ink jet recording, which comprises:
at least one dye; and
at least one of a compound having at least one phosphonic acid group and at least one carboxyl group and a compound having at least two phosphonic acid groups as a print density improver(s),
wherein the at least one of a compound having at least one phosphonic acid group and at least one carboxyl group and a compound having at least two phosphonic acid groups is a compound represented by formula (1):
Ym-Z-(PO3X2)n (1)
wherein Z represents a connecting group which may be substituted;
Y represents —CO2X, —SO3X or other anionic hydrophilic substituent;
X represents lithium;
m represents an integer of 0 or more; and
n represents an integer of 1 or more when m is 1 or more and Y contains —SO3X, and n represents an integer of 2 or more when m is 0 or when m is 1 or more but Y is free of —SO3X, with the proviso that when there are a plurality of Y's, they may be the same or different.

### Claim 2 (depends on 1)

The ink for ink jet recording according to claim 1,
wherein the at least one dye comprises at least one selected from the group consisting of phthalocyanine dye, monoazo dye, disazo dye, trisazo dye and tetrakisazo dye.

### Claim 3 (depends on 2)

The ink for ink jet recording according to claim 2,
wherein the disazo dye is represented by formula (2):
A-N═N—B—N═N—C (2)
wherein A, B and C each independently represents an aromatic or heterocyclic group which may be substituted, with the proviso that A and C each represents a monovalent group and B represents a divalent group.

### Claim 4 (depends on 3)

The ink for ink jet recording according to claim 3,
wherein the disazo dye is represented by formula (3):
wherein A and C each independently represents an aromatic or heterocyclic group which may be substituted;
R1 represents a hydrogen atom, halogen atom, aliphatic group, aromatic group, heterocyclic group, cyano group, carboxyl group, carbamoyl group, alkoxycarbonyl group, aryloxycarbonyl group, acyl group, hydroxyl group, alkoxy group, aryloxy group, silyloxy group, acyloxy group, carbamoyloxy group, heterocyclic oxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, alkylamino group, arylamino group, heterocyclic amino group, acylamino group, ureido group, sulfamoylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, alkylsulfonylamino group, arylsulfonylamino group, aryloxycarbonylamino group, nitro group, alkylthio group, arylthio group, alkylsulfonyl group, arylsulfonyl group, alkylsulfinyl group, arylsulfinyl group, sulfamoyl group, sulfo group or heterocyclic thio group which may be further substituted; and
D represents a nitrogen atom or —C(CN)═.

### Claim 5 (depends on 4)

The ink for ink jet recording according to claim 4,
wherein the disazo dye is represented by formula (4):
wherein R1, R2 and R3 each independently represents a hydrogen atom, halogen atom, aliphatic group, aromatic group, heterocyclic group, cyano group, carboxyl group, carbamoyl group, alkoxycarbonyl group, aryloxycarbonyl group, acyl group, hydroxyl group, alkoxy group, aryloxy group, silyloxy group, acyloxy group, carbamoyloxy group, heterocyclic oxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, alkylamino group, arylamino group, heterocyclic amino group, acylamino group, ureido group, sulfamoylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, alkylsulfonylamino group, arylsulfonylamino group, aryloxycarbonylamino group, nitro group, alkylthio group, arylthio group, alkylsulfonyl group, arylsulfonyl group, alkylsulfinyl group, arylsulfinyl group, sulfamoyl group, sulfo group or heterocyclic thio group which may be further substituted;
D represents a nitrogen atom or —C(CN)═;
X represents a hydrogen atom, alkaline metal, alkaline earth metal or substituted or unsubstituted ammonium cation; and
n represents an integer of from 0 to 3.

### Claim 6 (depends on 2)

The ink for ink jet recording according to claim 2,
wherein the phthalocyanine dye is represented by formula (5):
wherein G1, G2, G3 and G4 each independently represents a —SO—R10, —SO2—R10, —SO2NR11R12, sulfo group, —CONR11R12 or —CO2R11 in which R10 represents a substituted or unsubstituted alkyl, cycloalkyl, alkenyl, aralkyl, aryl or heterocyclic group, and R11 and R12 each independently represents a hydrogen atom or substituted or unsubstituted alkyl, cycloalkyl, alkenyl, aralkyl, aryl or heterocyclic group, with the proviso that there are a plurality of R10's, they may be the same or different;
H1, H2, H3 and H4 each independently represents a monovalent substituent;
a1 to a4 and b1 to b4 each independently represents the number of substituents G1 to G4 and H1 to H4, respectively;
a1 to a4 each independently represents an integer of from 0 to 4, with the proviso that a1 to a4 are not 0 at the same time;
b1 to b4 each independently represents an integer of from 0 to 4, with the proviso that when a1 to a4 and b1 to b4 each represents an integer of 2 or more, the plurality of G1's to G4's and H1's to H4's may be the same or different; and
M represents a hydrogen atom, metal atom or oxide, hydroxide or halide thereof.

### Claim 7 (depends on 1)

The ink for ink jet recording according to claim 1,
wherein the at least one dye has either or both of physical properties 1 and 2:
Physical property 1: |λmax (DMF)−λmax (water)|≧30 nm
Physical property 2: ε (DMF)≧ε (water)
wherein λmax (DMF) represents a maximum absorption wavelength in absorption spectrum measured in DMF;
λmax (water) represents a maximum absorption wavelength in absorption spectrum measured in water;
ε (DMF) represents a molar absorption coefficient in DMF; and
ε (water) represents a molar absorption coefficient in water.

### Claim 8

A print density improver for an ink for ink jet recording, which comprises at least one of a compound having at least one phosphonic acid group and at least one carboxyl group and a compound having at least two phosphonic acid groups,
wherein the at least one of a compound having at least one phosphonic acid group and at least one carboxyl group and the compound having at least two phosphonic acid groups is a compound represented by formula (1):
Ym-Z-(PO3X2)n (1)
wherein Z represents a connecting group which may be substituted;
Y represents —CO2X, —SO3X or other anionic hydrophilic substituent;
X represents lithium;
m represents an integer of 0 or more; and
n represents an integer of 1 or more when m is 1 or more and Y contains —SO3X, and n represents an integer of 2 or more when m is 0 or when m is 1 or more but Y is free of —SO3X, with the proviso that when there are a plurality of Y's, they may be the same or different.

### Claim 9 (depends on 8)

A method for improving print density in ink jet recording, which comprises utilizing a print density improver according to claim 8.