PURPOSE: To enhance the core substance holdability of a microcapsule, by performing the polycondensation of the hydrophilic melamine-formaldehyde resin initial condensate contained in water or a hydrophilic solvent containing an emulsifier having a specific composition.
CONSTITUTION: An emulsifier comprising a copolymer consisting of 92mol% or more of an unsaturated basic acid monomer and a hydrophobic monomer or a copolymer consisting of 80mol% or more of the unsaturated basic acid monomer, the hydrophobic monomer and diacetonacrylamide or N-vinyl pyrrolidone is prepared. The hydrophilic melamine/formaldehyde resin initial condensate contained in water or a hydrophilic solvent containing said emulsifier is polymerized to prepare a microcapsule covering the hydrophobic core substance. Further, the reducing viscosity of the aforementioned emulsifier in a 0.1% 1N-NaNO3 solution at 30°C must be 0.4dl/g or more.
SHINKOU KAZUYUKI
TOMINAGA YOICHI
NISHIGAITO YASUSHI
SANYO CHEMICAL IND LTD
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