| 摘要 |
PROBLEM TO BE SOLVED: To prevent a printed image from becoming discolored without deteriorating transparency by applying a transparent liquid containing chitosan or the salts of organic and inorganic acids of chitosan to the surface of a recording medium containing an artificial boehmite before or/and after the formation of an image, in an ink jet method. SOLUTION: Chitosan salts are cited as salts obtained from an inorganic and an organic acid. The preferable viscosity of a transparent liquid is 10,000-100,000cps. To limit the viscosity of the transparent liquid within this range, it is preferable to use the chitosan with a molecular weight of 300,000 or less, and also is preferable to limit the amount of the chitosan contained in the transparent liquid within the range of 0.1-10wt.% for the total amount of the transparent liquid. A solvent should be of such a type that it is chemically stable and a vapor pressure is low and the chitosan compound is smoothly soluble and further, it is the same as a solvent used in a water soluble dye ink. For the timing of applying the transparent liquid and the ink, it is preferable to apply them after the interlocking of the chitosan in the earlier applied transparent liquid or the dye in the ink with a recording medium. |
