INK CARTRIDGE COMPRISING WEAKLY ACIDIC NAPHTHALOCYANINE INK FORMULATION

• US 20100208014A1
• Filed: 02/21/2010
• Published: 08/19/2010
• Est. Priority Date: 07/10/2006
• Status: Active Grant

• Current Assignee: BASF SE
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Hall, Lachlan Everett, Silverbrook, Kia, Indusegaram, Sutharsiny, Vonwiller, Simone Charlotte, Starling, Scott Matthew, Ridley, Damon Donald, Gonzaga, Graciel
• Granted Patent: US 8,079,769 B2
• Time in Patent Office: Days
• US Class Current: 347/86
• CPC Class Codes: C09B 47/24 Obtaining compounds having —COOH or —SO3H radicals, or derivatives thereof, directly bound to the phthalocyanine radical
• CPC Class Codes: C09B 69/04 of anionic dyes with nitrogen containing compounds
• CPC Class Codes: C09D 11/328 characterised by dyes
• CPC Class Codes: G06K 19/06046 Constructional details

Abstract

An ink cartridge for an inkjet printer contains an aqueous ink formulation. The ink formulation comprising an IR-absorbing naphthalocyanine dye of formula (II):

or a salt form thereof, wherein:

• M is Ga(A¹);
• A¹ is an axial ligand selected from —OH, halogen, —OR³, —OC(O)R⁴ or —O(CH₂CH₂O)_eR^e wherein e is an integer from 2 to 10 and R^e is H, C_1-8 alkyl or C(O)C_1-8 alkyl;
• R¹ and R² may be the same or different and are selected from hydrogen or C_1-12 alkoxy;
• R³ is selected from C_1-12 alkyl, C_5-12 aryl, C_5-12 arylalkyl or Si(R^x)(R^y)(R^z);
• R⁴ is selected from C_1-12 alkyl, C_5-12 aryl or C_5-12 arylalkyl; and
• R^x, R^y and R^z may be the same or different and are selected from C_1-12 alkyl, C_5-12 aryl, C_5-12 arylalkyl, C_1-12 alkoxy, C_5-12 aryloxy or C_5-12 arylalkoxy.

The ink formulation has a characteristic pH in the range of 4 to 6.5.

Claims

1. An ink cartridge for an inkjet printer, said ink cartridge containing an aqueous ink formulation, said ink formulation comprising an IR-absorbing naphthalocyanine dye of formula (II):

or a salt form thereof, wherein;

M is Ga(A¹);

A¹ is an axial ligand selected from the group consisting of;

—

OH, halogen, —

OR³, —

OC(O)R⁴ or —

O(CH₂CH₂O)_eR^e wherein e is an integer from 2 to 10 and Re is H, C_1-8 alkyl and C(O)C_1-8 alkyl;

R¹ and R² may be the same or different and are selected from the group consisting of;

hydrogen or C_1-12 alkoxy;

R³ is selected from the group consisting of;

C_1-12 alkyl, C_5-12 aryl, C_5-12 arylalkyl and Si(R^x)(R^y)(R^z);

R⁴ is selected from the group consisting of C_1-12 alkyl, C_5-12 aryl and C_5-12 arylalkyl; and

R^x, R^y and R^z may be the same or different and are selected from the group consisting of;

C_1-12 alkyl, C_5-12 aryl, C_5-12 arylalkyl, C_1-12 alkoxy, C_5-12 aryloxy and C_5-12 arylalkoxy;

said formulation having a pH in the range of 4 to 6.5.

2. The ink cartridge of claim 1, wherein said ink formulation is buffered.

3. The ink cartridge of claim 1, wherein said ink formulation further comprises at least one base B, wherein a conjugate acid BH⁺ of said base B has a pK_a of between 4 and 9.

4. The ink cartridge of claim 3, wherein the conjugate acid BH⁺ has a pK_a of between 4.5 and 8.

5. The ink cartridge of claim 1, wherein the ink formulation comprises a nitrogen base, an oxyanion base or mixtures thereof.

6. The ink cartridge of claim 5, wherein said nitrogen base is a nitrogen-containing C_5-12 heteroaryl base.

7. The ink cartridge of claim 6, said nitrogen base is imidazole or pyridine.

8. The ink cartridge of claim 5, wherein said oxyanion base is a carboxylate base.

9. The ink cartridge of claim 8, wherein said carboxylate base is of formula R⁵C(O)O⁻

, wherein R⁵ is selected from C_1-12 alkyl, C_5-12 aryl or C_5-12 arylalkyl.

10. The ink cartridge of claim 5 comprising a nitrogen base and an oxyanion base.

11. The ink cartridge of claim 1, wherein R¹ and R² are both H.

12. The ink cartridge of claim 1, wherein M is Ga(OH).

13. An ink cartridge of claim 1, wherein said ink has a λ

_max of 800 nm or more.

14. An inkjet printer comprising a printhead in fluid communication with the ink cartridge according to claim 1.