| 摘要 |
PURPOSE:To enhance color development properties, light resistance and water resistance, by incorporating an alkali metal sulfate compound into a silica- containing recording medium. CONSTITUTION:This recording medium comprises a base consisting of an ordinary paper, a converted paper, a synthetic paper, a plastic film or the like, with silica and an alkali metal sulfate compound provided in or on the base. Silica is preferably a synthetic fine particulate silica having a specific surface area measured by the BET method of at least 100m<2>/g. To incorporate silica and the compound into the base, for example, the two components may be added simultaneously or separately in the process of making a paper for obtaining the base. A recording medium of the type in which the two components are contained in a coated layer on the surface of the base can be produced by adding the two components to a coating liquid for the base such as a paper, applying the resultant coating liquid to the base, and drying the applied liquid. With the alkali metal sulfate compound incorporated into a silica-containing recording medium, the light resistance of the medium can be markedly enhanced without degrading the excellent color development properties inherent in the silica-containing recording medium. |
