Radiation-curable inkjet inks and coatings

Patent metadata

Field	Value
Publication number	US-10501648-B2
Application number	US-201515324037-A
Country	US
Kind code	B2
Filing date	Jul 8, 2015
Priority date	Jul 11, 2014
Publication date	Dec 10, 2019
Grant date	Dec 10, 2019

Abstract

The present invention provides radiation-curable (UV-curable) inks and coatings for inkjet printing comprising an inert thermoplastic acrylic resin and multifunctional monomers. The inks and coatings can be applied in a single pass printing operation. Furthermore, the inks and coatings are suitable for the printing of food, pharmaceutical and other sensitive packaging materials, particularly of plastic materials. The acrylic polymer (or copolymer) preferably has a molecular weight of 10,000 g/mole, or less, and the ink comprises less than 5 wt % of any blend of monofunctional monomer. The inks and coatings of the invention are particularly suitable for curing by UV-LED radiation.

First claim

What is claimed is:

1. A radiation-curable inkjet ink or coating composition comprising:
a) one or more acrylic polymers in an amount of greater than 10 wt % based on a total weight of the ink or coating; and
b) one or more multifunctional monomers having two or more polymerizable groups per molecule;

wherein at least one multifunctional monomer is a hybrid monomer containing two or more different polymerizable groups per molecule;
wherein the radiation-curable inkjet ink or coating composition is non-aqueous;
wherein the composition contains greater than or equal to 40 wt % of polymerizable monomers, based on the total weight of the ink or coating;
wherein the composition contains one or more photoinitiators selected from the group consisting of thioxanthones, phosphine oxide compounds, alpha-hydroxy ketones, benzophenones, aminobenzoates, alpha-aminoalkylphenones, benzoin ethers and benzyl ketals, wherein at least one photoinitiator is a phosphine oxide; and
wherein a concentration of any blend of phosphine oxide photoinitiators is less than 1.0 wt % based on the total weight of the ink or coating composition.

2. The composition of claim 1 , wherein the one or more acrylic polymers are present in an amount of greater than 12 wt % based on the total weight of the ink or coating composition.

3. The composition of claim 1 , wherein the at least one multifunctional hybrid monomer contains both (meth)acrylate and vinyl ether functional groups.

4. The composition of claim 3 , in which the at least one multifunctional monomer containing both (meth)acrylate and vinyl ether functional groups is 2-(2-vinyloxyethoxy)ethyl acrylate.

5. The composition of claim 1 , containing a colorant.

6. The composition of claim 5 , wherein the colorant is an organic or inorganic pigment, or a dye.

7. The composition of claim 1 , wherein total concentration of the one or more photoinitiators is less than 8.0 wt % based on the total weight of the ink or coating composition.

8. The composition of claim 1 , wherein at least one or more of the thioxanthones is a polymeric thioxanthone and/or the at least one or more polymeric thioxanthone is present in a concentration of less than 2.0 wt % based on the total weight of the ink or coating composition.

9. The composition of claim 1 , having a viscosity of less than 15.0 mPa·s at 50° C.

10. A printed article comprising the inkjet ink or coating composition of claim 1 , and a substrate.

11. The printed article of claim 10 , wherein the substrate is selected from the group consisting of plastic, aluminum, glass, flexible packaging, rigid packaging, and the non-contact surface of any food packaging.

12. A method of printing comprising:
a) applying the ink or coating composition of claim 1 onto a substrate; and
b) curing the applied ink or coating by UV-LED radiation; and
wherein a total UV-dose of the UV-LED radiation is less than 300 mJ/cm 2 .

13. The method of claim 12 , wherein the ink or coating composition is printed via a single pass printing or coating operation.

14. The method of claim 12 , wherein the ink or coating is cured by UV-LED radiation within 5 seconds of being printed.

15. The composition of claim 1 , wherein when the composition contains multifunctional monomers that are not hybrid monomers, the composition contains greater than 25 wt % of one or more multifunctional hybrid monomers, based on the total weight of multifunctional monomers.

16. The composition of claim 1 , which contains less than 5 wt % of monofunctional monomers based on the total weight of the ink or coating composition.

Assignees

• Sun Chemical Corp

Inventors

• Illsley Derek
• Ward Damian
• Hall Stephen

Classifications

• C09D11/101 Primary

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

• C08F283/008

  on to unsaturated polymers · CPC title

• C09D4/06

  {Organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond} in combination with a macromolecular compound other than an unsaturated polymer of groups C09D159/00 - C09D187/00 · CPC title

• C09D11/38

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

• C09D11/107

  from unsaturated acids or derivatives thereof · CPC title