Printing device and printing method

#This application is a 371 application of the international PCT application serial no. PCT/JP2014/076972, filed on Oct. 08, 2014, which claims the priority benefit of Japan application no. 2013-211840, filed on Oct. 9, 2013; and Japan application no. 2014-061899, filed on Mar. 25, 2014. The entirety of each of the above-mentioned patent applications is hereby incorporated by reference herein and made a part of this specification.

#The present invention relates to a printing device and a printing method.

#In recent years, inkjet printers are spreading into a broad range of applications including printed matters printed for outdoor use such as outdoor advertising (for example, Non-Patent Document 1). In such a printed matter, a material for overcoat may be applied to an image printed thereon to improve weather resistance. The means for applying the overcoat material may include sprays, brushes, and dip coating.

#FIGS. 1A to 1C are drawings illustrating an example of a printing device 10 according to an embodiment of the present invention. FIG. 1A is a side view of the printing device 10, illustrating its main structural elements by way of an example. FIG. 1B is a top view of the printing device 10, illustrating its main structural elements by way of an example. FIG. 1C is a drawing of ink layers formed by the printing device 10, illustrated by way of an example.

#FIG. 2 is a table showing, by way of an example, detailed compositions of clear inks (base material) and of curing agents used in an example of the present invention.

#FIGS. 3A and 3B are illustrations relating to an experiment performed to study properties of overcoat layers 104 formed at different base material-curing agent mixing ratios. FIG. 3A shows printing conditions employed in the experiment. FIG. 3B is a table showing the experiment result.

#Hereinafter embodiments according to the present invention are described in detail with reference to the accompanying drawings. FIGS. 1A to 1C are drawings illustrating an example of a printing device 10 according to an embodiment of the present invention. FIG. 1A is a side view of the printing device 10, illustrating its main structural elements by way of an example. FIG. 1B is a top view of the printing device 10, illustrating its main structural elements by way of an example. FIG. 1C is a drawing of ink layers formed by the printing device 10, illustrated by way of an example.

#In an example hereinafter described, a printing device 10 is an inkjet printer for performing printing on a medium 50 by ink-jet technique, including a plurality of inkjet heads, a controller 26, a platen 18, a main scan driving unit 20, a sub scan driving unit 22, and a heater 24. The inkjet heads may include color ink heads 12y, 12m, 12c, and 12k (hereinafter, collectively color ink heads 12y-k), a clear ink head 14, and a curing agent head 16.

#The color ink heads 12y-k are each an inkjet head that forms on the medium 50 a color ink layer 102 that is an ink layer formed of a color ink. In this example, the color ink heads 12y-k discharge ink droplets of Y, M, C, and K color inks, respectively. A suitable example of each Y, M, C, and K color ink may be a solvent ink. The solvent ink may refer to an ink containing a solvent, specifically, an organic solvent. The organic solvent may be a hydrophobic organic solvent, for example. The organic solvent may be a volatile organic solvent.