| 摘要 |
PURPOSE:To enhance color development properties, light resistance and water resistance, by incorporating an amino acid into a silica-containing recording medium. CONSTITUTION:This recording medium comprises a base consisting of a converted paper, a synthetic paper, a plastic film or the like, with silica and an amino acid 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. The amino acid may be any of various alpha-, beta- or gamma-amino acids and other amino acids. Particularly preferable amino acids include sulfur-containing amino acids, such as methionine and cystine, and hydrochlorides thereof. To incorporate silica and the amino acid 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, applying the resultant coating liquid to the base, and drying the applied liquid. With the amino acid or a mixture thereof incorporated into a silica-containing recording medium, the light resistance of the medium can be enhanced without loosing the excellent color development properties inherent in the silica-containing recording medium. |
