ENERGY RAY-CURABLE INK COMPOSITION

• US 20090197988A1
• Filed: 02/04/2009
• Published: 08/06/2009
• Est. Priority Date: 02/05/2008
• Status: Active Grant

• Current Assignee: Hitachi Maxell Limited (Hitachi, Ltd.), Maxell, Ltd.
• Original Assignee: Hitachi Maxell Limited (Hitachi, Ltd.)
• Inventors: Kobayashi, Satoshi, Oya, Masayuki, Kito, Katsuyuki
• Granted Patent: US 8,124,666 B2
• Time in Patent Office: Days
• US Class Current: 522/26
• 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

Abstract

An object of the present invention is to provide an energy ray-curable ink composition which is excellent in curability and adhesion, and is also excellent in storage stability.

The present invention relates to an energy ray-curable ink composition comprising a coloring material; a polyfunctional monomer having three or more ethylenical double bonds in one molecule as a polymerizable compound; an α-aminoalkylphenone-based compound and a thioxanthone-based compound as photopolymerization initiators; and a hindered amine-based compound having a 2,2,6,6-tetramethylpiperidinyl group as an antigelling agent.

Claims

1. An energy ray-curable ink composition comprising a coloring material;

a polyfunctional monomer having three or more ethylenical double bonds in one molecule as a polymerizable compound;

an α

-aminoalkylphenone-based compound and a thioxanthone-based compound as photopolymerization initiators; and

a hindered amine-based compound having a 2,2,6,6-tetramethylpiperidinyl group as an antigelling agent.

2. The energy ray-curable ink composition according to claim 1, wherein the hindered amine-based compound has a 1-hydroxy-2,2,6,6-tetramethylpiperidinyl group.

3. The energy ray-curable ink composition according to claim 1, which contains, as the hindered amine-based compound, bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)sebacate.

4. The energy ray-curable ink composition according to any one of claims 1 to 3, which contains the polyfunctional monomer in an amount of 10 to 65% by mass, the α

-aminoalkylphenone-based compound in an amount of 2 to 20% by mass, the thioxanthone-based compound in an amount of 0.1 to 10% by mass and the hindered amine-based compound in an amount of 0.01 to 3% by mass, based on the entire amount of the ink composition.

5. The energy ray-curable ink composition according to any one of claims 1 to 3, which contains the α

-aminoalkylphenone-based compound in an amount of 40 to 99% by mass and the thioxanthone-based compound in an amount of 1 to 60% by mass, based on the entire amount of the photopolymerization initiator.

6. An energy ray-curable ink composition comprising a coloring material;

at least one of a polyfunctional monomer selected from the group consisting of trimethylolpropane tri(meth)acrylate and pentaerythritol tri(meth)acrylate as a polymerizable compound;

at least one of an α

-aminoalkylphenone-based compound selected from the group consisting of 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone, and a thioxanthone-based compound as photopolymerization initiators; and

bis (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)sebacate as an antigelling agent;

wherein

the energy ray-curable ink composition contains the polyfunctional monomer in an amount of 10 to 65% by mass, the α

-aminoalkylphenone-based compound in an amount of 2 to 20% by mass, the thioxanthone-based compound in an amount of 0.1 to 10% by mass and the bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)sebacate in an amount of 0.01 to 3% by mass, based on the entire amount of the ink composition; and

also contains the a-aminoalkylphenone-based compound in an amount of 40 to 99% by mass and the thioxanthone-based compound in an amount of 1 to 60% by mass, based on the entire amount of the photopolymerization initiator.