PHOTO-CURABLE INK COMPOSITION

• US 20150247044A1
• Filed: 08/29/2013
• Published: 09/03/2015
• Est. Priority Date: 08/31/2012
• Status: Active Grant

• Current Assignee: Hewlett-Packard Industrial Printing Ltd (HP Inc.)
• Original Assignee: Hewlett-Packard Industrial Printing Ltd (HP Inc.)
• Inventors: Brandstein, Or, Lisitsin, Nataly, Trubnikov, Alex, Cohen, Eytan
• Granted Patent: US 9,556,348 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 11/102 containing macromolecular compounds obtained by reactions other than those only involving unsaturated carbon-to-carbon bonds
• CPC Class Codes: C09D 11/107 from unsaturated acids or derivatives thereof
• CPC Class Codes: C09D 11/30 Inkjet printing inks
• CPC Class Codes: C09D 11/322 Pigment inks

Abstract

A photo-curable ink composition including colorant, water, photo-initiator, UV curable polyurethane dispersions, hydrophobic radiation-curable monomers and water-soluble or water-miscible radiation curable monomers. Also disclosed herein is a method for forming a printed article and an inkjet printing system using said photo-curable ink composition.

Claims

1. A photo-curable ink composition comprising colorant, water, photo-initiator, UV curable polyurethane dispersions, hydrophobic radiation-curable monomers and water-soluble or water-miscible radiation curable monomers.

2. The photo-curable ink composition of claim 1 wherein the water-soluble or water-miscible radiation curable monomers are present in the ink composition in an amount ranging from about 1 to about 15 wt % by total weight of the composition.

3. The photo-curable ink composition of claim 1 wherein the water-soluble or water-miscible radiation curable monomers include esters of acrylic or methacrylic acid with polyethylene glycol or with a mono-, di-, tri-, or tetra- hydric alcohol derived by ethoxylating a mono-, di, tri-, or tetra-hydric aliphatic alcohol of molecular weight less than 200 with ethylene oxide.

4. The photo-curable ink composition of claim 1 wherein the water-soluble or water-miscible radiation curable monomers are acrylate esters of polyethylene glycols made from polyethylene glycol having a molecular weight of from about 200 to about 1500 and acrylic esters of ethoxylated trimethylolpropane having from 9 to 30 ethoxylate residues.

5. The photo-curable ink composition of claim 1 wherein the water-soluble or water-miscible radiation curable monomers are ethoxylated tri-methylpropane triacrylates.

6. The photo-curable ink composition of claim 1 wherein the water-soluble or water-miscible radiation curable monomers are acrylamides monomers.

7. The photo-curable ink composition of claim 1 wherein the UV curable polyurethane dispersions are present in an amount representing from about 1 wt % to about 25 wt % by total weight of the composition.

8. The photo-curable ink composition of claim 1 wherein the hydrophobic radiation-curable monomers are acrylate monomers or vinyl monomers.

9. The photo-curable ink composition of claim 1 wherein the hydrophobic radiation-curable monomers are selected from the group consisting of vinyl caprolactam, hexanediol diacrylate, trimethylolpropane triacrylate and propoxylated neopentyl glycol diacrylate.

10. The photo-curable ink composition of claim 1 wherein the composition contains water in an amount ranging from about 10 to about 90 wt % by total weight of the ink composition.

11. A method for forming a printed article comprising:

a) providing a photo-curable ink composition containing colorant, water, photo-initiator, UV curable polyurethane dispersions, hydrophobic radiation-curable monomers and water-soluble or water-miscible radiation curable monomers;

b) providing a media substrate;

c) projecting of stream of droplets of said photo-curable ink composition onto the media substrate;

d) pinning said ink composition once printed on the media substrate;

e) drying said ink composition;

f) applying photo energy to the ink composition, said photo energy having a frequency and energy level suitable for curing the photo-curable ink composition.

12. The method for forming a printed article of claim 11, wherein the projection of stream of droplets of ink composition, onto the media substrate, is done via a piezoelectric printhead.

13. An inkjet printing system comprising:

a) a media substrate;

b) at least one photo-curable ink composition comprising colorant, water, photo-initiator, UV curable polyurethane dispersions, hydrophobic radiation-curable monomers and water-soluble or water-miscible radiation curable monomers;

c) photo energy sources configured to apply photo energy to said ink composition once printed on a substrate, said photo energy having a frequency and energy level suitable for pinning, drying and curing the photo-curable ink composition.

14. The inkjet printing system of claim 13, wherein the photo energy source is a UV light source.

15. A method for preparing photo-curable ink composition comprising:

a) providing in combination colorant, water, photo-initiator, UV curable polyurethane dispersions, hydrophobic radiation-curable monomers and water-soluble or water-miscible radiation curable monomers;

b) subjecting the combination to conditions under which the ink composition becomes substantially uniform;

c) and subjecting the combination to filtration.