| 摘要 |
A method for depositing an aqueous coating composition onto an ink layer or uninked surface in a printing process comprising (1) depositing a first layer of the ink onto a surface to be coated, (2) drying said ink layer, (3) determining a desired viscosity of an aqueous coating composition to be deposited onto said ink layer or said surface, said composition comprising (a) about 15-85% by weight of a film-forming polymer, said film forming polymer comprising 10-90% by weight of a high molecular weight polymer of an average molecular weight of about 30,000 to about 5,000,000 and 10-90% by weight of a low molecular weight polymer of average molecular weight of about 100 to about 20,000, (b) an amount of wetting agent effective to substantially eliminate levelling problems after deposition caused by surface tension, and (c) the remainder comprising a mixture of water and optionally a volatile organic solvent. (4) determining the temperature above or below ambient temperature at which said composition attains the viscosity previously determined, (5) maintaining the desired viscosity of said composition at the temperature determined earlier and (6) depositing the aqueous coating composition at the determined temperature onto said ink layer or said surface. |
