Transparent coatings for graphic applications

Abstract

Abstract This invention relates to transparent films for use in graphics applications, such as, for example, visual transparencies for overhead projectors. One disadvantage of presently available ink-receptive layers for transparent films for pen plotters and ink jet printers is that their high level of sorption capacity leads to poor dimensional stability, which, in turn, leads to curling of the film whenever moisture content changes, either due to imaging, or due simply to changes in humidity or to drying out due to the heat encountered on the stage of an overhead projector. Curl can be reduced by applying the same image receptive layer to both sides of the film, so that any expansion or contraction will be applied symmetrically to both sides of the film. This adds to manufacturing cost, and still may not completely eliminate curl, especially in cases where moisture content differs on opposite sides of the film. Accordingly, it would be desirable to provide an ink-receptive layer for transparent films that has good dimensional stability. This invention provides a hydrophilic, polymeric blend which provides improved durability and reduced curl when used as an image-receptive layer on graphic arts films. The blend comprises at least one water-absorbing, hydrophilic polymeric material, at least one hydrophobic polymeric material having acid functionality, and at least one polyethylene glycol. The layer formed from the blend provides high sorption capacity combined with good physical integrity even when wet, along with dimensional stability. The invention also provides sheets suitable for preparing visual transparencies having a backing bearing on at least one major surface thereof an image-receptive layer formed from the aforementioned blend.

Inventors

• 👤 Mohammed C/O Minnesota Mining And Igbal
• 👤 Armin James C/O Minnesota Mining And Paff

Bibliographic Details