Solvent-based ink composition for thermal inkjets comprising pyrrolidinone solvent

1. A solvent-based ink composition for a thermal inkjet printhead, said ink composition comprising:

(a) 20-80 wt. % of a compound of formula (A);

wherein:

R 1 is C 1-6 alkyl; and

each of R 2 , R 3 and R 4 is independently selected from the group consisting of: H, C 1-6 alkyl, halogen, OH, and C 1-6 alkoxy;

(b) 10-70 wt. % of a C 1-6 alcohol;

(c) 0.01-25 wt. % of a colorant; and

(d) 0.001-10 wt. % of a surfactant.

2. The ink composition of claim 1 , wherein:

R 1 is C 1-6 alkyl; and

each of R 2 , R 3 and R 4 is H.

3. The ink composition of claim 1 , wherein said compound of formula (A) is N-methyl-2-pyrrolidinone or N-ethyl-2-pyrollidinone.

4. The ink composition of claim 1 , wherein said C 1-6 alcohol is ethanol.

5. The ink composition of claim 1 , wherein said colorant is a dye or a pigment.

6. The ink composition of claim 1 , wherein said surfactant is a nonionic surfactant.

7. The ink composition of claim 1 , wherein said surfactant is non-polymeric.

8. The ink composition of claim 1 , wherein said composition does not comprise an acrylate polymer or copolymer.

9. The ink composition of claim 1 , wherein said composition does not comprise any polymers.

10. The ink composition of claim 1 , consisting only of said compound of formula (A), said C 1-6 alcohol, said colorant and 0.01-10 wt. % of a surfactant.

11. An ink cartridge for a thermal inkjet printhead, said ink cartridge containing the solvent-based ink composition according to claim 1 .

12. The ink cartridge of claim 11 , wherein said ink cartridge comprises said thermal inkjet printhead integrated therewith.

13. A substrate having an ink composition according to claim 1 disposed thereon.

14. The substrate of claim 13 , which is a semi-porous or non-porous substrate.

15. The substrate of claim 13 , which is a vinyl substrate.