Gallium naphthalocyanine salts exhibiting reduced kogation
A sulfonated dye salt of formula (II): wherein M is Ga(A 1 ); A 1 is an axial ligand selected from the group consisting of: —OH and halogen; and Z 1 + , Z 2 + , Z 3 + and Z 4 + are independently selected from the group consisting of: H and an ammonium cation including 3 or more hydroxyl groups. At least one of Z 1 + , Z 2 + , Z 3 + and Z 4 + is the ammonium cation. Such salts exhibit reduced kogation in thermal bubble-forming inkjet printheads.
1. A sulfonated dye salt of formula (II):
wherein
M is Ga(A 1 );
A 1 is an axial ligand selected from the group consisting of: —OH and halogen; and
Z 1 + , Z 2 + , Z 3 + and Z 4 + are independently selected from the group consisting of: H and an ammonium cation comprising at least 4 hydroxyl groups, wherein at least one of Z 1 + , Z 2 + , Z 3 + and Z 4 + is said ammonium cation.
2. The salt of claim 1 , wherein said ammonium cation comprises at least 5 hydroxyl groups.
3. The salt of claim 1 , wherein said ammonium cation is of formula (A):
wherein:
R 5 , R 6 , R 7 , R 8 , R 9 and R 10 are each independently selected from the group consisting of: H and —CH 2 OH.
4. The salt of claim 1 , wherein said ammonium cation is protonated 2,2-bis(hydroxymethyl)-2,2′,2″-nitrilotriethanol.
5. The salt of claim 1 , wherein at least three of Z 1 + , Z 2 + , Z 3 + and Z 4 + are said ammonium cation.
6. The salt of claim 1 , wherein each of Z 1 + , Z 2 + , Z 3 + and Z 4 + is said ammonium cation.
7. An inkjet ink comprising a salt according to claim 1 .
8. A method of reducing kogation in an inkjet printhead having a plurality of nozzles, each nozzle comprising: a nozzle chamber containing said ink; a heater element for heating said ink; and a nozzle opening for ejection of said ink, said method comprising:
printing from the printhead utilizing an inkjet ink comprising a sulfonated dye salt of formula (II):
wherein
M is Ga(A 1 );
A 1 is an axial ligand selected from the group consisting of: —OH and halogen; and
Z 1 + , Z 2 + , Z 3 + and Z 4 + are independently selected from the group consisting of: H and an ammonium cation comprising at least 4 hydroxyl groups, wherein at least one of Z 1 + , Z 2 + , Z 3 + and Z 4 + is said ammonium cation,
wherein said heater element is comprised of titanium nitride or a nitride of a titanium alloy.
9. The method of claim 8 , wherein said heater element is comprised of titanium aluminium nitride.
10. The method of claim 8 , wherein said heater element is a cantilever beam suspended across said nozzle chamber.
11. The method of claim 8 , wherein said printing includes at least 50 million drop actuations.
12. An inkjet printhead comprising a plurality of nozzles, each nozzle comprising: a nozzle chamber containing an inkjet ink; a heater element for heating said ink; and a nozzle opening for ejection of ink, wherein said heater element is comprised of titanium nitride or a nitride of a titanium alloy, and wherein said ink comprises a sulfonated dye salt of formula (II):
wherein
M is Ga(A 1 );
A 1 is an axial ligand selected from the group consisting of: —OH and halogen; and
Z 1 + , Z 2 + , Z 3 + and Z 4 + are independently selected from the group consisting of: H and an ammonium cation comprising at least 4 hydroxyl groups, wherein at least one of Z 1 + , Z 2 + , Z 3 + and Z 4 + is said ammonium cation.
13. A substrate having a salt according to claim 1 disposed thereon or therein.