Alternative phthalocyanine dyes suitable for use in offset inks

1. A phthalocyanine salt comprising one or more sulfonate groups, wherein a counterion of at least one sulfonate group is an ammonium cation comprising at least 20 carbon atoms.

2. The phthalocyanine salt of claim 1 , wherein said ammonium cation comprises at least one group C 6-30 alkyl group or at least one C 6-30 benzylalkyl group.

3. The phthalocyanine salt of claim 1 comprising a plurality of sulfonate groups.

4. The phthalocyanine salt of claim 1 , which is an IR-absorbing phthalocyanine salt.

5. The phthalocyanine salt of claim 1 , which is a naphthalocyanine.

6. The phthalocyanine salt of claim 1 , wherein said ammonium cation is of formula: N + (R m )(R n )(R s )(R t ), wherein:

each of R m , R n , R s and R t is independently selected from the group consisting of: C 1-30 alkyl, C 5-12 aryl and C 5-30 arylalkyl; or

R m and R n are together joined to form a C 5-10 heterocycloalkyl group, with R s and R t being independently selected from the group consisting of: C 1-30 alkyl, C 5-12 aryl and C 5-30 arylalkyl; or

R m , R n and R s are together joined to form a C 5-10 heteroaryl group, with R t being independently selected from the group consisting of: C 1-30 alkyl, C 5-12 aryl and C 5-30 arylalkyl.

7. The phthalocyanine salt of claim 6 , wherein at least one of R m , R n , R s and R t comprises 10 or more carbon atoms.

8. The phthalocyanine salt of claim 6 , wherein at least two of R m , R n , R s and R t comprise 6 or more carbon atoms.

9. The phthalocyanine salt of claim 6 , wherein at least three of R m , R n , R s and R t comprise 6 or more carbon atoms.

10. The phthalocyanine salt of claim 6 , wherein each of R m , R n , R s and R t is independently selected from C 1-30 alkyl.

11. The phthalocyanine salt of claim 6 , wherein said ammonium cation is of formula:

12. The phthalocyanine salt of claim 1 , wherein said salt is of formula (Ia):

wherein:

Q 1 , Q 2 , Q 3 and Q 4 are the same or different and are independently selected from the group consisting of: a C 3-20 arylene group or a C 3-20 heteroarylene group;

M is (H 2 ) or a metal selected from the group consisting of: Si(A 1 )(A 2 ), Ge(A 1 )(A 2 ), Ga(A 1 ), Mg, Al(A 1 ), TiO, Ti(A 1 )(A 2 ), ZrO, Zr(A 1 )(A 2 ), VO, V(A 1 )(A 2 ), Mn, Mn(A 1 ), Fe, Fe(A 1 ), Co, Ni, Cu, Zn, Sn, Sn(A 1 )(A 2 ), Pb, Pb(A 1 )(A 2 ), Pd and Pt;

A 1 and A 2 are axial ligands, which may be the same or different, and are selected from the group consisting of: —OH, halogen, —OR 3 , —OC(O)R 4 and —O(CH 2 CH 2 O) e R e wherein e is an integer from 2 to 10 and R e is H, C 1-8 alkyl and C(O)C 1-8 alkyl;

R 3 is selected from the group consisting of: C 1-20 alkyl, C 5-12 aryl, C 5-20 arylalkyl and Si(R x )(R y )(R z );

R 4 is selected from the group consisting of: C 1-20 alkyl, C 5-12 aryl and C 5-20 arylalkyl;

R x , R y and R z are 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; and

Z 1 + , Z 2 + , Z 3 + and Z 4 + may be the same or different and are each an ammonium cation comprising at least 20 carbon atoms.

13. The phthalocyanine salt of claim 1 , which is of formula (I):

wherein

M is Ga(A 1 );

A 1 is an axial ligand selected from the group consisting of: —OH, halogen, —OR 3 , —OC(O)R 4 and —O(CH 2 CH 2 O) e R 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;

R 3 is selected from the group consisting of: C 1-20 alkyl, C 5-12 aryl, C 5-20 arylalkyl and Si(R x )(R y )(R z );

R 4 is selected from the group consisting of: C 1-20 alkyl, C 5-12 aryl or C 5-20 arylalkyl;

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; and

Z 1 + , Z 2 + , Z 3 + and Z 4 + may be the same or different and are each an ammonium cation comprising at least 20 carbon atoms.

14. A solvent-based or oil-based ink comprising a phthalocyanine salt according to claim 1 .

15. An analog printer, or a module thereof, comprising an ink supply, a printing plate and means for disposing ink from said ink supply onto said plate, wherein said ink comprises a phthalocyanine salt according to claim 1 .

16. A substrate having a phthalocyanine salt according to claim 1 disposed thereon or therein.

17. The substrate of claim 1 , which is a label, packaging or surface of a product item.

18. A system for interacting with a coded substrate, said system comprising:

a substrate having human-readable information and machine-readable coded data disposed thereon or therein; and

a sensing device for reading the machine-readable coded data,

wherein said coded data comprises a phthalocyanine salt according to claim 1 .