Sacrificial coating and indirect printing apparatus employing sacrificial coating on intermediate transfer member

摘要

An indirect printing process comprises providing an inkjet printing apparatus comprising an intermediate transfer member. A wet sacrificial coating composition is deposited onto the intermediate transfer member. The wet sacrificial coating composition is made from ingredients comprising: a waxy starch; at least one hygroscopic material; at least one surfactant; and a liquid carrier. The wet sacrificial coating composition is dried to form a dry sacrificial coating. Droplets of ink are ejected in an imagewise pattern onto the dry sacrificial coating. The ink is at least partially dried to form a substantially dry ink pattern. Both the substantially dry ink pattern and the sacrificial coating are transferred from the intermediate transfer member to a final substrate. At least one cross-linking agent is applied to cross-link the sacrificial coating. The cross-linking agent is applied to at least one of: a) the intermediate transfer member prior to depositing the wet sacrificial coating composition, b) the wet sacrificial coating composition after depositing the wet sacrificial coating composition onto the intermediate transfer member, c) the dry sacrificial coating on the intermediate transfer member, d) the dry sacrificial coating on the final substrate.

主权项

1. An indirect printing process comprising:
providing an inkjet printing apparatus comprising an intermediate transfer member; depositing a wet sacrificial coating composition onto the intermediate transfer member, the wet sacrificial coating composition made from ingredients comprising:
a waxy starch;at least one hygroscopic material;at least one surfactant; anda liquid carrier; drying the wet sacrificial coating composition to form a dry sacrificial coating; ejecting droplets of ink in an imagewise pattern onto the dry sacrificial coating; at least partially drying the ink to form a substantially dry ink pattern; transferring both the substantially dry ink pattern and the sacrificial coating from the intermediate transfer member to a final substrate; and applying at least one cross-linking agent to cross-link the sacrificial coating, wherein the cross-linking agent is applied to at least one of: a) the intermediate transfer member prior to depositing the wet sacrificial coating composition, b) the wet sacrificial coating composition after depositing the wet sacrificial coating composition onto the intermediate transfer member, c) the dry sacrificial coating on the intermediate transfer member, or d) the dry sacrificial coating on the final substrate.