Radiation curable ink jet ink compositions

• US 6,593,390 B1
• Filed: 05/19/2000
• Issued: 07/15/2003
• Est. Priority Date: 12/05/1997
• Status: Expired due to Fees

• Current Assignee: Xaar Technology Limited (XAAR, PLC)
• Original Assignee: Xaar Technology Limited (XAAR, PLC)
• Inventors: Johnson, Steve, Woods, Jill
• Primary Examiner(s): Berman, Susan W.
• Application Number:
  US09/575,868
• Time in Patent Office: 1,152 Days
• Field of Search: 522/75, 522/81, 522/83, 522/99, 522/182, 522/181, 522/74, 522/91
• US Class Current: 522/74
• CPC Class Codes: B41M 5/0011 Pre-treatment or treatment during printing of the recording material, e.g. heating, irradiating after-treatment of prints B41M7/00; printers for treating or overcoating copy materials before, during or after printing B41J11/0015
• CPC Class Codes: B41M 5/0047 by ink-jet printing
• CPC Class Codes: B41M 5/0064 on plastics, horn, rubber, or other organic polymers
• 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 11/36 based on non-aqueous solvents

Abstract

A radiation curable ink jet ink having a viscosity not greater than 35 mPa.s at 30° C. and comprising a colorant component, a diluent consisting essentially of reactive liquid material and, optionally, at least one photopolymerization catalyst and wherein the reactive liquid material is formed of both monofunctional and polyfunctional material and comprises 5 to 30% by weight of at least one oligomer.

Claims

1. A radiation-curable ink jet ink, in a liquid and uncured form having a viscosity not greater than 35 mPa.s at 30°

C. as measured using a Brookfield Viscometer fitted with a small sample adaptor having a No. 18 spindle and a rotational speed of 60 rpm, giving a shear rate of 79.2 sec<sup>−

1</sup>, said ink comprising a colorant component, a diluent consisting essentially of reactive liquid material, a silicon derivative containing carbon-carbon unsaturation which is polymerizable by radiation and, optionally, at least one photopolymerization catalyst, wherein the reactive liquid material comprises both monofunctional material having a single unsaturated carbon-carbon bond polymerizable by radiation and polyfunctional material having a plurality of unsaturated carbon-carbon bonds polymerizable by radiation, the reactive liquid material further comprises 5% to 30% by weight, based upon the total weight of the reactive liquid material, of at least one oligomer having at least one unsaturated carbon-carbon bond polymerizable by radiation, wherein the reactive liquid material comprises at least 20% by weight, based upon the total weight of the reactive liquid material, of the monofunctional material.

2. An ink jet ink of claim 1 wherein said at least one oligomer forms not more than 25% by weight of the reactive liquid material.

3. An ink jet ink of claim 1 wherein the colorant comprises a pigment dispersed in the diluent.

4. An ink jet ink of claim 1 wherein the reactive liquid material comprises components selected from the group consisting of acrylates, methacrylates, and N-vinyl pyrrolidone.

5. An ink jet ink of claim 1 wherein said reactive liquid material comprises monofunctional, difunctional and trifunctional or higher functional components.

6. An ink jet ink of claim 1 wherein the monofunctional material of the diluent comprises at least one monomer selected from the group consisting of long chain aliphatic acrylates, acrylates of branched chain alcohols, acrylates of alkoxylated alcohols, acrylates of cyclic alkanols, acrylates of polycyclic alkanols, and N-vinyl pyrrolidone.

7. An ink jet ink of claim 6 wherein the monofunctional material comprises isobornyl acrylate.

8. An ink jet ink of claim 1 wherein the monofunctional material forms not more than 50% by weight of the reactive liquid material.

9. An ink jet ink of claim 1 wherein at least 5% by weight of the reactive liquid material comprises difunctional material.

10. An ink jet ink of claim 1 wherein greater than 10% by weight but not more than 30% by weight of the reactive liquid material comprises trifunctional material or higher functional material.

11. An ink jet ink of claim 1 comprising two or more photoinitiators.

12. An ink jet ink of claim 1 wherein at least one photoinitiator promotes cure in the frequency range 350 nm to 400 nm.

13. A method of printing on a substrate comprising the steps of directing an ink of claim 1 from a printhead of an ink jet printer toward a print-receiving surface of said substrate and, during its travel from the printhead to the substrate and/or after deposition on the substrate, exposing the ink to radiation to cure the ink.

14. A printed substrate having a surface carrying print comprising a cured ink of claim 1.

15. A printed substrate of claim 14 wherein the surface is plastic.

16. A radiation-curable ink jet ink, in a liquid and uncured form, having a viscosity not greater than 35 mPa.s at 30°

C. as measured using a Brookfield Viscometer fitted with a small sample adaptor having a No. 18 spindle and a rotational speed of 60 rpm, giving a shear rate of 79.2 sec<sup>−

1</sup>, said ink comprising a colorant component, a diluent consisting essentially of reactive liquid material and, optionally, at least one photopolymerization catalyst, wherein the reactive liquid material comprises;

monofunctional monomeric material having a single unsaturated carbon-carbon bond polymerizable by radiation;

polyfunctional monomeric material having a plurality of unsaturated carbon-carbon bonds polymerizable by radiation; and

5% to 30% by weight, based upon the total weight of the reactive liquid material, of at least one oligomer having at least one unsaturated carbon-carbon bond polymerizable by radiation;

wherein the reactive liquid material comprises at least 20% by weight, based upon the total weight of the reactive liquid material, of the monofunctional material, including monofunctional oligomer material;

wherein greater than 10% by weight but not more than 30% by weight of the reactive liquid material comprises trifunctional monomer material or higher functional monomer material.

17. An ink jet ink of claim 16 further including a silicone derivative containing carbon-carbon unsaturation which is polymerizable by radiation.

18. An ink jet ink of claim 16 wherein said at least one oligomer forms not more than 25% by weight of the reactive liquid material.

19. An ink jet ink of claim 18 further including a silicone derivative containing carbon-carbon unsaturation which is polymerizable by radiation.

20. An ink jet ink of claim 16 wherein the colorant comprises a pigment dispersed in the diluent.

21. An ink jet ink of claim 16 wherein the reactive liquid material comprises components selected from the group consisting of acrylates, methacrylates, and N-vinyl pyrrolidone.

22. An ink jet ink of claim 16 wherein said reactive liquid material comprises monofunctional, difunctional and trifunctional or higher functional components.

23. An ink jet ink of claim 16 wherein the monofunctional material of the diluent comprises at least one monomer selected from the group consisting of long chain aliphatic acrylates, acrylates of branched chain alcohols, acrylates of alkoxylated alcohols, acrylates of cyclic alkanols, acrylates of polycyclic alkanols, and N-vinyl pyrrolidone.

24. An ink jet ink of claim 23 wherein the monofunctional material comprises isobornyl acrylate.

25. An ink jet ink of claim 16 wherein the monofunctional material forms not more than 50% by weight of the reactive liquid material.

26. An ink jet ink of claim 16 wherein at least 5% by weight of the reactive liquid material comprises difunctional material.

27. An ink jet ink of claim 16 wherein greater than 10% by weight but not more than 30% by weight of the reactive liquid material comprises trifunctional material or higher functional material.

28. An ink jet ink of claim 16 comprising two or more photoinitiators.

29. An ink jet ink of claim 28 wherein at least one photoinitiator promotes cure in the frequency range 350 nm to 400 nm.

30. A method of printing on a substrate comprising the steps of directing an ink of claim 16 from a printhead of an ink jet printer toward a print-receiving surface of said substrate and, during its travel from the printhead to the substrate and/or after deposition on the substrate, exposing the ink to radiation to cure the ink.

31. A printed substrate having a surface carrying print comprising a cured ink of claim 16.

32. A printed substrate of claim 31 wherein the surface is plastic.