Active energy ray curable ink composition and method for manufacturing printed matter using same
To provide an active energy ray-curable ink composition that contains high rates of raw materials derived from biomass and can maintain basic characteristics, such as compatibility. Provided is an active energy ray-curable ink composition containing a pigment, a compound having ethylenically unsaturated bonds, and a rosin-modified alkyd resin, wherein the rosin-modified alkyd resin is a condensed polymer of an acid ingredient containing a resin acid, a fatty acid, and a polybasic acid with a polyhydric alcohol, and has a solubility parameter (sp) value of 9.0 to 11.0 (cal/cm 3 ) 1/2 as measured by turbidimetric titration and an acid value of 1 to 50 mg KOH/g.
1. A method of manufacturing printed matter, the method comprising:
printing on a synthetic resin base material via a resin relief printing that uses an active energy ray-curable ink composition, wherein
the active energy ray-curable ink composition comprises:
a pigment,
a compound having ethylenically unsaturated bonds, and
a rosin-modified alkyd resin, and
the rosin-modified alkyd resin is a condensed polymer of an acid ingredient containing a resin acid, a fatty acid, and a polybasic acid with a polyhydric alcohol, and has a solubility parameter value of 9.0 to 11.0 (cal/cm 3 ) 1/2 as measured by turbidimetric titration and an acid value of 1 to 50 mg KOH/g.
2. The method of manufacturing printed matter according to claim 1 , wherein the oil length, which is the ratio (mass %) of the mass of the fatty acid moiety to the mass of the entire rosin-modified alkyd resin, is 30 to 85.
3. The method of manufacturing printed matter according to claim 1 , wherein the rosin-modified alkyd resin contains a fatty acid having 8 to 16 carbon atoms.
4. The method of manufacturing printed matter according to claim 1 , wherein the rosin-modified alkyd resin contains a fatty acid of coconut oil or palm kernel oil.
5. The method of manufacturing printed matter according to claim 1 , wherein the rosin-modified alkyd resin has a weight average molecular weight of 1,000 to 70,000 g/mol.
6. The method of manufacturing printed matter according to claim 1 , wherein the active energy ray-curable ink composition further contains a photopolymerization initiator.