Low migration energy curable inks

Patent metadata

Field	Value
Publication number	US-9714355-B2
Application number	US-201414765196-A
Country	US
Kind code	B2
Filing date	Jan 30, 2014
Priority date	Feb 15, 2013
Publication date	Jul 25, 2017
Grant date	Jul 25, 2017

Abstract

Disclosed is a composition such as a pigmented free radical UV-curable inkjet liquid composition for the printing of food packaging materials, which when cured in ambient air produces minimal contamination of the foodstuff. This composition uses non-polymeric photoinitiators having molecular weights less than 500 amu that migrate at levels below the specified SML (specific migration limit).

First claim

We claim:

1. An inkjet composition comprising at least one photoinitiator, polymerizable components, and a multifunctional amino acrylate having a total functionality of greater than 2 wherein:
(a) at least 40% (w/w) of the total photoinitiator content comprises one or more photoinitiator having a molecular weight of less than 500 amu;
(b) said composition is a free radical UV-curable composition; and
(c) wherein greater than 50% by weight of the polymerizable component is a blend of difunctional monomers.

2. The composition of claim 1 , wherein at least 80% (w/w) of the total photoinitiator content comprises the one or more photoinitiator having the molecular weight of less than 500 amu.

3. The composition of claim 1 , wherein 100% (w/w) of the total photoinitiator content comprises the one or more photoinitiator having the molecular weight of less than 500 amu.

4. The composition of claim 1 further comprising a colorant.

5. The composition of claim 1 being an ink.

6. The composition of claim 1 being an inkjet ink.

7. The composition of claim 1 which when cured with a UV-dose of up to 300 mJ/cm 2 in air, causes contamination of any foodstuff, resulting from unbound components of the composition, of less than 10 ppb of each individual component or of less than a recognized specific migration limit for any composition component.

8. The composition of claim 1 , wherein the at least one photoinitiator having the molecular weight of less than 500 amu is selected from bis-phosphine oxide photoinitatior, hydroxy-ketone photoinitatior and combination or blend thereof.

9. The composition of claim 8 , wherein the bis-phosphine oxide photoinitiator has the following chemical structure:

10. The composition of claim 8 , wherein the hydroxyl-ketone photoinitiator is a difunctional hydroxy-ketone photoinitatior, having the following structure:

11. The composition of claim 8 , wherein the hydroxyl-ketone photoinitiator is a difunctional hydroxy-ketone photoinitatior, having the following structure:

12. The composition of claim 1 , wherein the total photoinitiator content is up to 10% (w/w) of total composition content.

13. The composition of claim 1 , wherein the total photoinitiator content is greater than 3.0% (w/w) of total composition content.

14. The composition of claim 1 , wherein greater than 90% by weight of the polymerizable components is a blend of difunctional monomers.

15. The composition of claim 1 , wherein greater than 95% by weight of the polymerizable components is a blend of difunctional monomers.

16. The composition of claim 1 , wherein 100% by weight of the polymerizable components is a blend of difunctional monomers.

17. The composition of claim 1 , wherein less than 10% by weight of the polymerizable components is one or more monofunctional acrylate monomer.

18. The composition of claim 1 further comprising oligomers and/or polymers with polymerizable groups, wherein the polymerizable groups are selected from acrylate, methacrylate, vinyl ether, allyl ether, propenyl ether, maleate, fumarate, ethylenic acrylamide, (meth)acrylamide, any other reactive group that is polymerizable by a free radical propagation process and a blend thereof.

19. The composition of claim 1 having a viscosity of less than 12.0 mPa·s at 50° C.

20. The composition of claim 1 having a viscosity of less than 11.0 mPa·s at 45° C.

21. The composition of claim 1 having a viscosity of less than 7.5 mPa·s at 45° C.

22. A composition comprising the composition of claim 1 that has been cured in air.

23. A composition comprising the composition of claim 1 that has been cured with a UV-dose of less than 300 mJ/cm 2 .

24. A printed article comprising the composition of claim 1 .

25. The printed article of claim 24 which is a food package.

26. The printed article of claim 25 , wherein the composition is applied to a surface of a plastic film for the food package.

27. The printed article of claim 25 , wherein the ink is applied to a surface of a paper or paperboard substrate for the food package.

28. A method of printing an ink composition, comprising applying to a substrate the ink composition of claim 5 .

Assignees

• Sun Chemical Corp

Inventors

• Illsley Derek
• Moncur Samuel
• Ward Damian
• Hall Stephen

Classifications

• C09D11/322

  Pigment inks · CPC title

• C09D11/101

  Inks specially adapted for printing processes involving curing by wave energy or particle radiation, e.g. with UV-curing following the printing · CPC title

• C09D11/30 Primary

  Inkjet printing inks · CPC title

• C08F2/50

  with sensitising agents · CPC title

• C09D133/14

  of esters containing halogen, nitrogen, sulfur or oxygen atoms in addition to the carboxy oxygen · CPC title