| 摘要 |
A surface coating applied on a substrate as well as a method of preparing a surface coated substrate are provided. A mixture comprising about 40% polyvinyl acetate and about 60% polyvinyl alcohol is applied to a porous substrate. Then, the mixture is heated. The polyvinyl alcohol cures by evaporation, and the mixture separates into a hydrophilic layer of polyvinyl alcohol and a hydrophobic layer of polyvinyl acetate, and the hydrophilic layer is between the hydrophobic layer and the substrate. A water-soluble ink is then deposited into the surface coating, and the ink is generally repelled by the hydrophobic layer, and is generally absorbed by the hydrophilic layer. Additionally, the hydrophobic layer protects from fading the ink which is absorbed into the hydrophilic layer, causes the ink to spread less in the hydrophilic layer, allows a charge to be applied to the same side of the substrate on which the ink is deposited, and allows an enhanced surface charge to be applied. Preferably, the surface coating can maintain a surface charge density of between about 10,000 volts and about 14,000 volts. If more than one color of ink is deposited into the surface coating, the hydrophobic layer causes a second color ink to be repelled less from a first color of ink in the surface coating. The surface coating can be coated with a water-based coating substance.
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