Radiation curable inks

• US 7,977,402 B2
• Filed: 10/10/2007
• Issued: 07/12/2011
• Est. Priority Date: 10/11/2006
• Status: Active Grant

• Current Assignee: Kao Collins, Inc. (KAO Corporation)
• Original Assignee: Collins Industries Incorporated (AIP LLC)
• Inventors: Madhusoodhanan, Sudhakar, Nagvekar, Devdatt S.
• Primary Examiner(s): McClendon; Sanza L
• Application Number:
  US11/973,743
• Publication Number:
  US 20080090930A1
• Time in Patent Office: 1,371 Days
• Field of Search: 522/74, 522/71, 522/77, 522/168, 522/178, 522/182, 522/183, 522/181, 522/121, 522/113, 106/31.13, 106/31.6, 523/160, 523/300
• US Class Current: 522/183
• CPC Class Codes: C08F 2/46 Polymerisation initiated by wave energy or particle radiation
• CPC Class Codes: C08F 2/50 with sensitising agents
• CPC Class Codes: C09D 11/101 Inks specially adapted for printing processes involving curing by wave energy or particle radiation, e.g. with UV-curing following the printing
• CPC Class Codes: C09D 11/30 Inkjet printing inks

Abstract

Radiation curable ink compositions for impulse printheads are described. The compositions include a photoinitiator system, containing both a photocation polymerization initiator and a free-radical photoinitiator, an acrylate ester of a carboxylic acid ester, and at least one radiation curable material.

Claims

1. A radiation curable ink composition for impulse printheads, comprising:

a) a photoinitiator system which comprises both a photocation polymerization initiator and a free-radical photoinitiator, each in the amount of about 1 to about 12 wt. %;

b) from about 0.5 to about 30 wt. % of an acrylate ester of a carboxylic acid ester represented by the formula;

2. The radiation curable ink composition of claim 1 wherein the carboxylate ester moiety is derived from alpha,alpha-dimethyl-Caproic acid, alpha-ethyl-alpha-methyl-Caproic acid, alpha,alpha-diethyl-Caproic acid, alpha,alpha-diethyl-Valeric acid, alpha,alpha-dimethyl-Capric acid, alpha-butyl-alpha-ethyl-Capric acid, alpha,alpha-dimethyl-Enanthic acid, alpha, alpha-diethyl-Pelargonic acid, alpha-butyl-alpha-methyl-Caproic acid, alpha,alpha-dimethyl-Caprylic acid, alpha-methyl-alpha-propyl-Caproic acid, alpha-ethyl-alpha-methyl-Enanthic acid, alpha-methyl-alpha-propyl-Valeric acid, alpha-ethyl-alpha-methyl-Caprylic acid, alpha-butyl-alpha-methyl-Caprylic acid, alpha-ethyl-alpha-propyl-Caproic acid, alpha-ethyl-alpha-propyl-Valeric acid, alpha-butyl-alpha-ethyl-Pelargonic acid, alpha,alpha-dimethyl Propionic acid (pivalic acid), neodecanoic acid and combinations thereof.

3. The radiation curable ink composition of claim 1 wherein the radiation curable material comprises a mono-functional monomer, a poly-functional monomer and a di-functional monomer.

4. The radiation curable ink composition of claim 1 wherein the radiation curable material comprises a mono-functional monomer and a poly-functional monomer, and is substantially free of di-functional monomer.

5. The radiation curable ink composition of claim 1 wherein the radiation curable material comprises a mono-functional monomer and a di-functional monomer, and is substantially free of a poly-functional monomer.

6. The radiation curable ink composition of claim 1 wherein the radiation curable material comprises a mono-functional oxetane.

7. The radiation curable ink composition of claim 1 wherein the photocation polymerization initiator and the free-radical photoinitiator are each independently utilized in an amount of about 0.5 to about 15 wt. %, based on the total weight of the ink.

8. The radiation curable ink composition of claim 1 wherein the acrylate ester of carboxylate acid ester is utilized in an amount of about 0.5 to about 30 wt. %, based on the total weight of the ink.

9. The radiation curable ink composition of claim 1 wherein the at least one radiation curable material comprises a mono-functional component in an amount of about 1 to about 70 wt. %, a poly-functional component in an amount of about 0 to about 95 wt. %, and a di-functional component in an amount of about 0 to about 95 wt. %, based on the total weight of the ink.

10. The radiation curable ink composition of claim 1 wherein the at least one radiation curable material comprises a mono-functional component in an amount of about 3 to about 60 wt. %, a poly-functional component in an amount of about 5 to about 80 wt. %, and a di-functional component in an amount of about 5 to about 80 wt. %, based on the total weight of the ink.

11. The radiation curable ink composition of claim 1 further comprising a silane adhesion promoter.

12. The radiation curable ink composition of claim 1 wherein the composition has a jet operating window at a jetting frequency of at least about 1 Hz to about 32 kHz, and wherein the composition exhibits stable jetting after residing in the printhead for a period of at least 1 day.

13. The radiation curable ink composition of claim 1 wherein the composition has a jet operating window at a jetting frequency of at least about 1 Hz to about 16 kHz, and wherein the composition exhibits stable jetting, after residing in the printhead for a period of at least 1 day.

14. The radiation curable ink composition of claim 11 wherein the composition has a jet operating window at a jetting frequency of at least about 1 Hz to about 32 kHz, and wherein the composition exhibits stable jetting, after residing in the printhead for a period of at least 1 day.

18. The radiation curable ink composition of claim 1 wherein the acrylate ester monomer of the carboxylic acid ester is utilized in an amount of about 1 to about 25 wt. %.

19. The radiation curable ink composition of claim 1 wherein the ink composition has a viscosity of about 5 to about 70 cPs at 25°

C.

15. A radiation curable ink composition for impulse printheads, comprising:

a) a photoinitiator system which comprises both , based on the total weight of the ink, from about 2 to about 10 wt. % of a photocation polymerization initiator and, based on the total weight of the ink, from about 1 to about 12 wt. % of a free-radical photoinitiator;

b) from about 1 to about 25 wt. % of an acrylate ester of a carboxylic acid ester represented by the formula;

16. The radiation curable ink composition of claim 15, wherein the radiation curable functional group comprises a mono-functional oxetane and a di-functional oxetane.

17. The radiation curable ink composition of claim 15, having an elongation of at least 40%.

20. The radiation curable ink composition of claim 15 wherein the ink composition has a viscosity of about 5 to about 70 cPs at 25°

C.