| 摘要 |
PROBLEM TO BE SOLVED: To obtain microcapsules which are stable mechanically and chemically and which express strong writing images quickly from environmentally desirable raw materials by making capsule walls from reaction products of guanidine compounds and polyisocyanates. SOLUTION: A materials to be encapsulated and polyisocyante are made into an oily phase by means of an org. water-immiscible inert solvent such as arom. hydrocarbons and carboxylic esters. Then, the oily phase is mixed into an aq. phase optionally comprising additives and stirred to make a fine emulsion. Thereafter, an aq. soln. of guanidine is added to the emulsion, and stirred with heating. Microcapsules thus prepared from environmentally desirable raw materials, polyisocyanate and the guanidine compd., are highly safe and stable mechanically and chemically, which produce strong writing images when applied on non-carbon copying paper. |
