The present invention relates to an ink receptive layer and an image article imaged with a UV-curable ink.
Typical promotional window graphics fall into two main areas, adhesive coated vinyl and cling vinyl films. Such films are usually screen printed with UV-curable inks. The artwork utilizes line colors, which tends to maximize the visual impact of the graphic as compared to 4-color printing. The line color printing creates an almost continuous layer of ink on the graphic film. This large amount of ink (up to five layers of UV-cured ink in localized areas of the graphic) significantly decreases the ductile strength of the film, which becomes more brittle and can break or tear more easily as a result of the brittle UV-cured ink layers adhering to the film.
Imaged cling vinyl films tend to have very good visual presentation when first applied to glass. However, such imaged films tend to lift and bubble over time because of very low peel adhesion to the glass. Adhesive coated vinyl graphic films adhere well to glass. However, such graphic films can tear or break into small pieces during removal due to decreased ductility from the UV-cured ink layers. Such tearing or breakage makes removal of the graphic films more difficult, and increases removal time.
In addition, anchorage of the UV-curable ink after cure to the film is important to the initial application of the graphic to a substrate. During application of the graphic to a substrate, stretching (or extension) of the graphic can occur. Current vinyl graphics films have the potential for the ink to flake off at low film extensions, decreasing the visual impact of the graphic.
One method to alleviate tearing of the film and flaking of the ink is to significantly increase the thickness of the vinyl film. However, if the film thickness is increased to, for example, above 6 mils (above about 150 micrometers), to address these issues, the graphic costs become commercially prohibitive.
Polyolefin based graphics films are also used for promotional window graphics. Although these films have improved tear strength after imaging, the adhesion of UV-curable screen print inks to the polyolefin is typically less that that of vinyl, resulting in more pronounced ink flaking.
USPTO Backgrounds
USPTO Backgrounds