A high solids content, aqueous, microcapsule-containing printing ink is prepared by forming microcapsules in situ in a printing ink vehicle. The microcapsules are preferably prepared by interfacial polymerization or interfacial crosslinking between a reactant, such as a polyisocyanate dissolved in an oily solution and a coreactant such as a polysalt of casein and diethylene triamine present in an aqueous solution into which the oily solution is dispensed. The aqueous solution contains water and preferrably a non-volatile diluent such as a non-reducing sugar, for example methyl glucoside. The oil-containing microcapsules contain an oil solvent and a mixture of dye precursors which upon reaction with a color developer produces an intense black image. The printing ink preferably has a 60-70% by weight solids content and may be used as a low-coat-weight CB coating for preparing carbonless copy paper.
通过在印刷油墨载体中就地形成微胶囊来制备高固体含量的含
水微胶囊印刷油墨。微胶囊最好是通过界面聚合或界面交联来制备,界面聚合或界面交联的反应物有溶解在油性溶液中的多
异氰酸酯,核心反应物有
酪蛋白和
二乙三胺的多盐,核心反应物存在于
水性溶液中,油性溶液被分配到
水性溶液中。
水溶液中含有
水,最好还含有非挥发性稀释剂,如非还原糖,例如
甲基葡萄糖苷。含油微胶囊含有油溶剂和
染料前体混合物,与
显色剂反应后可产生浓黑图像。印刷油墨的固体含量最好为 60-70%(按重量计),可用作制备无碳复写纸的低涂布量 CB 涂层。