| 摘要 |
PROBLEM TO BE SOLVED: To suppress the generation of giant particles in microcapsules and eliminate spot pollutions without especially impairing the recording properties peculiar to a pressure-sensitive recording paper by having a polyalkylene oxide in a side chain and polydimethylsiloxane in a main chain. SOLUTION: The emulsification assistant is not defined to a block copolymer exemplified by the formula (wherein, R is an alkylene group; R1 is an alkyl group or a hydrogen atom; m,n,a and b are each an integer) but is such as a polymer having a polyalkylene oxide as a side chain in the main chain of a polydimethyl siloxane, a polymer having plural sets of blocks of different lengths or a random copolymer having a polydimethylsiloxane part and a part with a side chain which are random-polymerized. The HLB value which indicates a balance between the hydrophilic nature and the lipophilic nature of a nonionic surface active agent as the emulsion assistant, is 12-17 and this agent is dissolved in water and this solution is added. Thus it is possible to suppress the generation of giant particles in the microcapsules and eliminate spot contaiminations on a pressure-sensitive recording paper. |
