| 摘要 |
PURPOSE:To obtain a recording material having a white ground tone, excellent preservation stability before printing and fixation and favorable recording sensitivity, by incorporating a specified polyisocyanate compound as a wall film material for microcapsules. CONSTITUTION:A polyisocyanate compound of general formula I is incorporated as a wall film material for microcapsules. In the formula, each of R1 and R4 is a 1-15C alkyl, haloalkyl, cycloalkyl, aryl or aralkyl which has at least one isocyanate group, and each of R2 and R3 is phenylene or naphthalylene which may be substd. by a halogen, 1-4C alkyl or phenyl. The compound of formula I may be, for example, an adduct of a diol such as 4,4'-thiobisphenol and 2,2'-thiobisphenol with a polyisocyanate such as m-phenylene diisocyanate and p-phenylene diisocyanate. Microcapsules containing a diazonium compound therein can be prepared by a method wherein a core substance comprising the diazonium compound is emulsified or dispersed in an aqueous medium, and a film of a high molecular weight substance is formed around each of oily droplets of the core substance being obtained. |
