Actinic radiation curing jet printing ink

Disclosed is an active energy beam curable inkjet printing inks including a pigment, a compound containing two or more ethylenic double bonds, a compound containing one ethylenic double bond and having a molecular weight of 90 to 210. The sheetfed offset ink has low viscosity, excellent photo-polymerizability, remarkably excellent curing property, good dispersion stability, causes no dissolution and swelling of ink contacting materials in a printer, and shows excellent discharge stability from nozzles, an excellent adherence property to a recording medium, excellent solvent resistance and water resistance.

Conventionally, as offset printing inks excellent in water resistance, there are those obtained by dispersing or dissolving an oil-soluble dye in a high boiling point solvent and those obtained by dissolving an oil-soluble dye in a volatile solvent.

As to colorants that have been used, dyes are inferior to pigments in various kinds of resistance such as light resistance. However, it is generally not easy to disperse a pigment stably in an organic solvent, and it is usually difficult to secure a stable dispersibility and discharging property.

As to ink solvents, an offset ink using a high boiling point solvent shows no solvent volatilization on a non-absorbing type recording medium, and manifests difficult drying through the evaporation of solvents, hence impossibility of printing onto non-absorbing type substrates. On the other hand, in the case of an ink using a volatile organic solvent, it is possible to form excellent prints even on a non-absorbing substrate by the adhesive property of a resin used and evaporation of solvents. However, since a volatile solvent is the main component of the ink, drying by volatilization of a solvent is very quick on the nozzle surface of a head, and frequent maintenance is required.

One object of the present invention is to provide an active energy beam curable inkjet ink having low viscosity, excellent photo-polymerizability, excellent curing property, and good stability.

Another object of the present invention is to provide an active energy beam curable printing inks causing no dissolution and swelling of ink contact materials in a printer, and showing excellent discharge stability from nozzles, excellent adherence to a recording medium, and excellent solvent resistance and water resistance.