UV-curable inkjet ink composition

• US 10,479,903 B2
• Filed: 12/16/2016
• Issued: 11/19/2019
• Est. Priority Date: 01/07/2016
• Status: Active Grant

• Current Assignee: Altemira Company Limited
• Original Assignee: Showa Aluminum Can Corporation (Apollo Global Management, Inc.)
• Inventors: Ojima, Shinichi, Ikeda, Kazunori, Suwa, Asumi
• Primary Examiner(s): Whiteley, Jessica
• Application Number:
  US16/062,986
• Publication Number:
  US 20180371271A1
• Time in Patent Office: 1,068 Days
• Field of Search: 522 1, 520 1
• CPC Class Codes: B41J 2/01 Ink jet
• CPC Class Codes: B41M 1/28 on metals
• CPC Class Codes: B41M 1/40 Printing on bodies of particular shapes, e.g. golf balls, candles, wine corks sublimation or volatilisation of pre-printed design B41M5/035
• CPC Class Codes: B41M 5/00 Duplicating or marking methods; Sheet materials for use therein by using light-sensitive materials G03; electrography, magnetography G03G ; repeatedly usable boards or tablets for writing or drawing B43L1/00
• CPC Class Codes: B41M 5/0047 by ink-jet printing
• CPC Class Codes: B41M 5/0058 on metals and oxidised metal surfaces
• CPC Class Codes: B41M 7/0081 using electromagnetic radiation or waves, e.g. ultraviolet radiation, electron beams
• 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 11/30 Inkjet printing inks
• CPC Class Codes: C09D 11/322 Pigment inks
• CPC Class Codes: C09D 11/38 characterised by non-macromolecular additives other than solvents, pigments or dyes

Abstract

A UV-curable inkjet ink composition is curable by irradiation with ultraviolet light and includes a monofunctional monomer (A), a polyfunctional monomer (B), a photopolymerization initiator (C), and a colorant (D), wherein the composition has a hydroxyl value within the range of not less than 1 mgKOH/g and not more than 100 mgKOH/g, and is for forming, by inkjet printing, an ink layer 14 provided between a curved outer peripheral surface of a cylindrical can base 12 made of a metal material, and a coating layer 16 made of an aqueous coating material.

Claims

1. A UV-curable inkjet ink composition that contains a monofunctional monomer (A), a polyfunctional monomer (B), a photopolymerization initiator (C) and a colorant (D) and is cured by irradiation with ultraviolet light, wherein

a hydroxyl value of the UV-curable inkjet ink composition is in a range of not less than 1 mgKOH/g and not more than 100 mgKOH/g, and

the UV-curable inkjet ink composition forms, by inkjet printing, an ink layer provided between a curved outer peripheral surface of a can base made of a cylindrical metallic material and a covering layer made of an aqueous coating material.

2. The UV-curable inkjet ink composition according to claim 1, wherein at least one of the monofunctional monomer (A) and the polyfunctional monomer (B) includes a hydroxyl-containing monomer.

3. The UV-curable inkjet ink composition according to claim 1, wherein a blending amount ratio of the photopolymerization initiator (C) and the colorant (D) satisfies 0.5≤

(photopolymerization initiator/colorant)≤

5.0.

4. The UV-curable inkjet ink composition according to claim 1, wherein the photopolymerization initiator (C) contains an acylphosphine-oxide-based photopolymerization initiator.

5. The UV-curable inkjet ink composition according to claim 1, wherein a blending amount ratio of the monofunctional monomer (A) and the polyfunctional monomer (B) satisfies 2≤

(monofunctional monomer (A)/polyfunctional monomer (B))≤

20.

6. The UV-curable inkjet ink composition according to claim 1, wherein an average number of functional groups of a polymerizable compound containing the monofunctional monomer (A) and the polyfunctional monomer (B) is in a range of not less than 1.0 and not more than 1.4.

7. The UV-curable inkjet ink composition according to claim 1, wherein the monofunctional monomer (A) contains a monofunctional monomer having a glass transition temperature of less than 20°

C., and a content rate of the monofunctional monomer having the glass transition temperature of less than 20°

C. in the monofunctional monomer (A) is in a range of not less than 50% by mass and not more than 100% by mass.

8. A can, comprising:

a can base made of a cylindrical metallic material,

an ink layer disposed on a surface of the can base, the ink layer obtained by printing the UV-curable inkjet composition according to claim 1, and

a covering layer made of an aqueous coating material disposed on the ink layer.

9. The can according to claim 8, wherein at least one of the monofunctional monomer (A) and the polyfunctional monomer (B) includes a hydroxyl-containing monomer.

10. The can according to claim 8, wherein a blending amount ratio of the photopolymerization initiator (C) and the colorant (D) satisfies 0.5≤

(photopolymerization initiator/colorant)≤

5.0.

11. The can according to claim 8, wherein the photopolymerization initiator (C) contains an acylphosphine-oxide-based photopolymerization initiator.

12. The can according to claim 8, wherein a blending amount ratio of the monofunctional monomer (A) and the polyfunctional monomer (B) satisfies 2≤

(monofunctional monomer (A)/polyfunctional monomer (B))≤

20.

13. The can according to claim 8, wherein an average number of functional groups of a polymerizable compound containing the monofunctional monomer (A) and the polyfunctional monomer (B) is in a range of not less than 1.0 and not more than 1.4.

14. The can according to claim 8, wherein the monofunctional monomer (A) contains a monofunctional monomer having a glass transition temperature of less than 20°

C., and a content rate of the monofunctional monomer having the glass transition temperature of less than 20°

C. in the monofunctional monomer (A) is in a range of not less than 50% by mass and not more than 100% by mass.