IP Library Granted Patent US 7,370,953
Granted Patent B2
US 7,370,953 · App. 10/771,464 · Granted May 13, 2008

Inkjet recording ink

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Quick Facts
Patent No.
US 7,370,953
App. No.
10/771,464
Granted
May 13, 2008
Kind
B2
Abstract

An inkjet recording ink includes at least one yellow-azo dye having specific properties or a specific structure dissolved and/or dispersed in an aqueous medium and containing a water-miscible organic solvent having a specific solubility with respect to dye.

Claims (13)

1. An inkjet recording ink comprising:

an aqueous medium comprising at least one water-miscible organic solvent; and

at least one dye dissolved and/or dispersed in the aqueous medium, wherein said at least one dye has a maximum absorption spectrum λmax at a wavelength range of from 390 nm to 470 nm and a I(λmax+70 nm)/I(λmax) ratio of not greater than 0.4, in which I(λmax) is the absorbance at λmax and I(λmax+70 nm) is the absorbance at λmax+70 nm,

wherein the inkjet recording ink exhibits an accelerated fading rate constant of not greater than 5.0×10 2 [hour −1 ], in which the accelerated fading rate constant is determined by printing the ink on a reflection medium to prepare a printed matter, measuring a reflection density through a status A filter to define an initial value of reflection density (D B ) in the yellow region by one point between 0.90 and 1.10, and acceleratedly fading the printed matter by using an ozone fading tester capable of always generating 5 ppm of ozone, so as to define the fading rate constant from the time required until the reflection density reaches 80% of the initial value; and

said at least one water-miscible organic solvent satisfies one of the following requirements 1) and 2):

1) said at least one dye has a solubility in all of said at least one water-miscible organic solvent of less than 10 (g/100 g) at 25° C.;

2) said at least one dye has a solubility in at least one of said at least one water-miscible organic solvent of not smaller than 10 (g/100 g) at 25° C., with the proviso that the sum of the weight of the water-miscible organic solvent is not greater than 10% of the weight of the ink.

2. The inkjet recording ink as defined in claim 1 , wherein the dye exhibits a λmax at a wavelength range of from 390 nm to 470 nm and a I(λmax+70 nm)/I(λmax) ratio of not greater than 0.2 in which I(λmax) is the absorbance at λmax and I(λmax+70 nm) is the absorbance at λmax+70 nm.

3. The inkjet recording ink as defined in claim 1 , wherein the dye has an oxidation potential of more positive than 1.0 V (vs SCE).

4. The inkjet recording ink as defined in claim 2 , wherein the dye has an oxidation potential of more positive than 1.0 V (vs SCE).

5. The inkjet recording ink as defined in claim 1 , wherein the total amount of said at least one water-miscible organic solvent is 1 to 60 weight % based on the ink.

6. The inkjet recording ink as defined in claim 1 , wherein the number of the water-miscible organic solvents is at least two in the case 2).

7. The inkjet recording ink as defined in claim 1 , wherein the amount of said at least one dye is 0.2 to 20 weight % based on the ink.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 15, 2007
From: FUJIFILM HOLDINGS CORPORATION (FORMERLY FUJI PHOTO FILM CO., LTD.)
To: FUJIFILM CORPORATION
Reel/Frame 018904/0001 →