Ink composition, inkjet-recording method and printed material
View Patent ↗An ink composition including a cationically polymerizable compound having a styryl or α-methylstyryl group such as 4-methylstyrene and a photocationic polymerization initiator. The ink composition preferably further includes another cationically polymerizable compound having at least one group selected from oxirane and oxetane groups.
1. An ink composition, comprising a cationically polymerizable compound having a styryl or α-methylstyryl group and a photocationic polymerization initiator, wherein the number of the styryl or α-methylstyryl groups in the cationically polymerizable compound having a styryl or α-methylstyryl group is 2 or 3.
2. The ink composition of claim 1 , wherein the cationically polymerizable compound having a styryl or α-methylstyryl group is a compound having an electron-donating functional group at least on one of p- and o-positions of the styryl group.
3. The ink composition of claim 2 , wherein the electron-donating functional group is an amino, hydroxyl, alkoxy, or alkyl group.
4. The ink composition of claim 2 , wherein the electron-donating functional group is an alkoxy, alkyl, or dimethylamino group.
5. The ink composition of claim 1 , wherein the total content of the cationically polymerizable compound having a styryl or α-methylstyryl group is 5% by mass to 95% by mass with respect to the total mass of the ink composition.
6. The ink composition of claim 1 , wherein the total content of the cationically polymerizable compound having a styryl or α-methylstyryl group is 20% by mass to 95% by mass with respect to the total mass of the ink composition.
7. The ink composition of claim 1 , wherein the total content of the cationically polymerizable compound having a styryl or α-methylstyryl group is 30% by mass to 95% by mass with respect to the total mass of the ink composition.
8. The ink composition of claim 1 , further comprising a cationically polymerizable compound other than the cationically polymerizable compound having a styryl or α-methylstyryl group.
9. The ink composition of claim 8 , wherein the other cationically polymerizable compound is a compound having at least one group selected from oxirane and oxetane groups.
10. The ink composition of claim 1 , further comprising a colorant.
11. The ink composition of claim 1 , further comprising a pigment or an oil-soluble dye.
12. The ink composition of claim 1 , further comprising an oil-soluble dye, wherein the oxidation potential of the oil-soluble dye is at least 1.0 V (vsSCE).
13. An inkjet-recording method comprising;
ejecting the ink composition of claim 1 on a recording medium.
14. An inkjet-recording method comprising;
hardening the ink composition of claim 1 .
15. An inkjet-recording method comprising;
ejecting the ink composition of claim 1 on a recording medium by an inkjet printer and
hardening the ejected ink composition by irradiating it with an active radiation ray.
16. A printed material comprising; a hardened composition obtained by hardening the ink composition of claim 1 .
17. The ink composition of claim 1 , wherein the photocationic polymerization initiator is a sulfonium salt.