| 摘要 |
A chlorinated diphenyl solvent solution of Crystal Violet Lactone as well as an emulsion for use in pressure-sensitive copying papers which contain microcapsules wherein said solvent solution is encapsulated as an internal liquid phase may be substantially prevented from becoming blue stained by the action of light by incorporating at least 0.5 percent, preferably 2.5-10 percent by weight based on the amount of Crystal Violet Lactone of 2-[p,p'-bis(dimethylamino)benzhydrol]-5-dimethylaminobenzoic acid in said solvent solution. In a pressure-sensitive copying paper, the rear surface of a writing sheet being intended to be brought into contact with the clay-coated surface of a recording sheet, which has been coated with the aforesaid emulsion, does not substantially tend to become blue stained on exposure to the sunlight even for a considerably long period of time, and hence is of great commercial usefulness.
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