Azo metal-complexed dyes, ink jet ink compositions and ink jet printing methods

1. A printing ink composition comprising a metal-complexed dye represented by the formula

or a salt thereof

wherein:

M is copper;

R 1 and R 2 each independently is a solubilizing group;

R 3 is selected from the group consisting of:

(1) alkyl;

(2) cyano;

(3) COOH; and

(4) CONH2;

X 1 and X 2 each independently is a counterion;

Z is a ligand;

n is an integer of from 1 to 3;

m is an integer of from 1 to 3; and

p is an integer of from 1 to 3;

dissolved or dispersed in a liquid carrier.

2. The printing ink composition according to claim 1 wherein said liquid carrier comprises water.

3. The printing ink composition according to claim 1 , wherein at least one of X 1 and X 2 is an alkali metal ion.

4. The printing ink composition according to claim 1 which includes a dye represented by the formula

wherein R 5 is alkyl and M, R 1 , R 2 , X 1 , X 2 , Z, m, n and p are as defined in claim 1 .

5. The printing ink composition according to claim 1 which includes a dye represented by the formula

6. An ink jet ink comprising a solution of a dye according to claim 1 in water, aqueous alcohol or an aqueous glycol.

7. A printing ink composition comprising a metal-complexed dye represented by the formula

wherein:

M is copper;

R 1 and R 2 each independently is a solubilizing group;

R 3 is selected from the group consisting of:

(1) alkyl;

(2) cyano;

(3) COOH; and

(4) CONH 2 ;

X 1 and X 2 each independently is a counterion;

n is an integer of from 1 to 3; and

m is an integer of from 1 to 3;

dissolved or dispersed in a liquid carrier.

8. The printing ink composition according to claim 7 wherein said liquid carrier comprises water.

9. The printing ink composition according to claim 7 wherein at least one of X 1 and X 2 is an alkali metal ion.

10. An ink jet cartridge comprising a housing having walls defining a reservoir and an outlet opening, the cartridge containing an ink jet ink according to claims 1 or 7 .

11. An ink jet printing method comprising forming a plurality of drops of an ink composition, and directing said drops onto an ink receptive material to form an image thereon, wherein said ink composition is according to claims 1 or 7 .

12. A metal-complexed dye represented by the formula

where

M is copper;

R 1 and R 2 each independently is a solubilizing group;

R 5 is alkyl cyano, COOH or CONH 2 ;

X 1 and X 2 each independently is a counterion;

Z is a ligand;

n is an integer of from 1 to 3;

m is an integer of from 1 to 3; and

p is an integer of from 1 to 3.

13. A metal-complexed dye according to claim 12 wherein R 5 is methyl.