Photo-curable ink jet ink set and ink jet recording method using the same
A photo-curable ink jet ink set includes an undercoating photo-curable ink jet ink containing a (meth)acrylic acid ester having a vinyl ether group expressed by general formula (I), and an overcoating photo-curable ink jet ink. The undercoating photo-curable ink jet ink has a higher surface tension than the overcoating photo-curable ink jet ink.
1. A photo-curable ink jet ink set comprising:
an undercoating photo-curable ink jet ink having a surface tension and containing a (meth)acrylic acid ester having a vinyl ether group expressed by general formula (I):
CH 2 ═CR 1 —COOR 2 —O—CH═CH—R 3 , wherein R 1 represents a hydrogen atom or a methyl group, R 2
represents a divalent organic residue having a carbon number of 2 to 20, and R 3 represents a hydrogen atom or a monovalent organic residue having a carbon number of 1 to 11; and
an overcoating photo-curable ink jet ink,
wherein the undercoating photo-curable ink jet ink contains:
only an acrylic surfactant,
a photopolymerization initiator, and
a white pigment, and
wherein the overcoating photo-curable ink jet ink contains a modified silicone surfactant.
2. The photo-curable ink jet ink set according to claim 1 , wherein the difference in surface tension between the undercoating photo-curable ink jet ink and the overcoating photo-curable ink jet ink is 5 mN/m or more.
3. The photo-curable ink jet ink set according to claim 1 , wherein the content of the (meth)acrylic acid ester in the undercoating photo-curable ink jet ink is 20% to 80% by mass relative to the total mass of the undercoating photo-curable ink jet ink.
4. The photo-curable ink jet ink set according to claim 1 , wherein the overcoating photo-curable ink jet ink contains a (meth)acrylic acid ester having a vinyl ether group expressed by general formula (I) in a lower content than the content of the (meth)acrylic acid ester in the undercoating photo-curable ink jet ink.
5. An ink jet recording method using the photo-curable ink jet ink set as set forth in claim 1 , the method comprising:
forming a coating of the undercoating photo-curable ink jet ink on a recording medium; and
forming a coating of the overcoating photo-curable ink jet ink on the coating of the undercoating photo-curable ink jet ink.
6. An ink jet recording method using the photo-curable ink jet ink set as set forth in claim 2 , the method comprising:
forming a coating of the undercoating photo-curable ink jet ink on a recording medium; and
forming a coating of the overcoating photo-curable ink jet ink on the coating of the undercoating photo-curable ink jet ink.
7. An ink jet recording method using the photo-curable ink jet ink set as set forth in claim 3 , the method comprising:
forming a coating of the undercoating photo-curable ink jet ink on a recording medium; and
forming a coating of the overcoating photo-curable ink jet ink on the coating of the undercoating photo-curable ink jet ink.
8. An ink jet recording method using the photo-curable ink jet ink set as set forth in claim 4 , the method comprising:
forming a coating of the undercoating photo-curable ink jet ink on a recording medium; and
forming a coating of the overcoating photo-curable ink jet ink on the coating of the undercoating photo-curable ink jet ink.
9. The photo-curable ink jet ink according to claim 1 , wherein the (meth)acrylic acid ester having a vinyl ether group is 2-(vinyloxyethoxy)ethyl acrylate.