Water-based ink for inkjet and method for producing printed matter
One embodiment relates to a water-based ink for an inkjet containing a pigment, a fixing resin, an organic solvent and water, wherein the fixing resin includes an A-B block polymer having an A block and a B block, the A block contains a structural unit (P-1) having an anionic functional group, and the acid value of the A-B block polymer is from 5 to 80 mgKOH/g.
1. A water-based ink for an inkjet comprising a pigment, a fixing resin, an organic solvent and water, wherein
the fixing resin comprises an A-B block polymer having an A block and a B block,
the A block contains a structural unit (P-1) having an anionic functional group,
the A block and the B block are each, independently, a block containing one type of polymer selected from among a styrene-based polymer, a (meth)acrylic-based polymer and a styrene-(meth)acrylic-based polymer,
an amount of structural units contained in the A block is 5 to 25 mol % of a total molar amount of structural units contained in the A-B block polymer,
an amount of the structural unit (P-1) having an anionic functional group contained in the A block is at least 85 mol % of a total molar amount of the structural unit (P-1) having an anionic functional group contained in the A-B block polymer,
the acid value of the A-B block polymer is from 5 to 80 mgKOH/g, and
a glass transition temperature (TgB) of the B block is from 70 to 100° C.
2. The water-based ink for an inkjet according to claim 1 , wherein an amount of the structural unit (P-1) having an anionic functional group contained in the A block is from 40 to 80% by weight of all the structural units contained in the A block.
3. The water-based ink for an inkjet according to claim 1 , wherein the B block contains a structural unit (P-2) having an alkyl group of 8 to 30 carbon atoms and/or a structural unit (P-3) having an aromatic ring.
4. The water-based ink for an inkjet according to claim 3 , wherein the B block contains a structural unit having an alkyl group of 10 to 30 carbon atoms as the structural unit (P-2) having an alkyl group of 8 to 30 carbon atoms.
5. The water-based ink for an inkjet according to claim 3 , wherein the B block contains a styrene-based structure as the structural unit (P-3) having an aromatic ring.
6. The water-based ink for an inkjet according to claim 1 , wherein the organic solvent comprises a glycol ether and/or a 1,2-alkanediol of 3 or more carbon atoms.
7. The water-based ink for an inkjet according to claim 1 , further comprising a surfactant, wherein the surfactant comprises a siloxane-based surfactant.
8. A method for producing printed matter that comprises printing the water-based ink for an inkjet according to claim 1 onto a substrate.
9. Printed matter produced using the method for producing printed matter according to claim 8 .