Water-based UV inkjet ink

Patent metadata

Field	Value
Publication number	US-9845400-B2
Application number	US-201515312493-A
Country	US
Kind code	B2
Filing date	May 22, 2015
Priority date	May 29, 2014
Publication date	Dec 19, 2017
Grant date	Dec 19, 2017

Abstract

The invention describes the use of a water-based UV curable inkjet printing ink wherein the ink is basic due to the presence of a tertiary amine, allowing the complete dissolution of an acid functional photoinitiator of Formula I or Formula IA (wherein R 1 , R 2 , R 3 , n, q, and y are as defined herein). This combination of photoinitiator and tertiary amine allows the rapid low dosage UV curing of a water-based UV formulation using a UV LED light source.

First claim

What is claimed is:

1. An alkaline energy curable water-based inkjet ink or coating composition comprising:
a) a photoinitiator of Formula I:

wherein each R 1 is an independently selected hydrogen or a C 1 -C 4 alkyl group, and n is a number from 0 to 8;

or a photoinitiator of Formula IA wherein Formula I is further substituted with R 2 and R 3 ,
wherein each R 2 and R 3 is independently selected from the group consisting of hydrogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, and halogen;
y is 0 or 1;
q is 0, 1, or 2;
and n is a number from 0 to 8,

and the photoinitiator has a structure of Formula IA:

b) a polymer which is water-soluble, or dispersible in water either as a liquid in liquid emulsion or a particle suspension;
c) water; and
d) one or more tertiary amine synergists;
wherein the composition has a pH of between about 7.0 and about 9.5; and wherein the ratio of the amine synergists to the photoinitiator of Formula I or IA is greater than 1:1.

2. The alkaline energy curable water-based inkjet ink or coating composition of claim 1 comprising:
a) the photoinitiator of Formula IA
b) the polymer which is water-soluble, or dispersible in water, either as a liquid in liquid emulsion, or a particle suspension;
c) water; and
d) the one or more tertiary amine synergists;
wherein the composition has a pH of between about 7.0 and about 9.5.

3. The composition of claim 1 , which is curable by an LED light source.

4. The composition of claim 1 , further containing one or more water compatible solvents, one or more water soluble monomers, and/or one or more additional photoinitiators.

5. The composition of claim 4 , wherein:
a) the photoinitiator of Formula I or IA is present in an amount of 0.1-2%;
b) the polymer which is water-soluble, or dispersible in water either as a liquid in liquid emulsion or particle suspension is present in an amount of 15-35% of a water dispersion containing about 40% solids;
c) water is present in an amount of 20-80%;
d) the one or more tertiary amine synergists are present in an amount of 0.1-4%;
e) the one or more water soluble monomers are present in an amount of 0-15%;
f) the one or more water compatible solvents are present in an amount of 0-40%; and
g) the one or more additional photoinitiators are present in an amount of 0-2%.

6. The composition of claim 1 , wherein a ratio of amine to the photoinitiator of Formula 1 or Formula IA is greater than 1.5:1, greater than 2:1, greater than 5:1, greater than 10:1, greater than 15:1 or greater than 20:1.

7. The composition of claim 1 , wherein the one or more tertiary amine synergists comprises at least one N,N-dialkylamino benzoic acid; and the composition further comprises at least one other tertiary amine synergist.

8. The composition of claim 1 , further containing one or more additives selected from the group consisting of biocides, anti-mold additives, defoamers, de-aerators and surfactants and/or a colorant.

9. The composition of claim 1 , wherein the photoinitiator of Formula I or Formula IA is selected from the group consisting of 2-[carboxymethoxy]thioxanthone, 2-[2-ethyl(carboxymethoxy)]thioxanthone, 2-[2-methyl(carboxymethoxy)]thioxanthone, and 2-[carboxy-n-pentyl-5-oxy]thioxanthone.

10. The composition of claim 1 , wherein the polymer comprises an aqueous acrylated polyurethane dispersion.

11. The composition of claim 1 , wherein the water is deionized.

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

Assignees

• Sun Chemical Corp

Inventors

• Herlihy Shaun Lawrence
• Rowatt Brian
• Illsley Derek

Classifications

• 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

• C09D11/102 Primary

  containing macromolecular compounds obtained by reactions other than those only involving unsaturated carbon-to-carbon bonds · CPC title

• C09D11/033

  characterised by the solvent · CPC title

• C07D335/16

  Oxygen atoms, e.g. thioxanthones · CPC title

• C09D11/38

  characterised by non-macromolecular additives other than solvents, pigments or dyes · CPC title