Abstract: A production method of microcapsules using a copolymer including at least three types of monomers including 50 to 90 by weight of acrylic acid, 2 to 40% by weight of an acrylamidealkylsulfonic acid such as acrylamidepropanesulfonic acid, and 2 to 15% by weight of an alkylacrylate such as butylacrylate as an anionic water-soluble polymer as an emulsifier and a reaction promoter for a core substance of the microcapsules, whereby obtaining microcapsules for use in pressure-sensitive copy paper having wall films of an amine-aldehyde condensation polymer which reduces spot staining generated when the capsules are used in pressure-sensitive copy paper by reducing coarse particles present in traces in the microcapsule slurry.

Abstract: The present invention relates to a color-former having microcapsules which comprise an electron-donating colorless dye dispersed in a hydrophobic liquid. The present invention provides a color-former using both an electron-donating colorless dye and a hydrophobic liquid which previously were unable to be used because of the lack of solubility. A uniform and stable dispersion of electron-donating colorless dye in a hydrophobic core liquid is prepared by using oil-soluble non-ionic surfactant.