| 摘要 |
PURPOSE:To efficiently form microcapsules having superior core substance retentivity by polycondensing a precondensate of aminoaldehyde resin in the presence of an anionic copolymer contg. vinylsulfonic acid and an arom. vinyl compd. CONSTITUTION:An aq. soln. of a copolymer consisting of vinylsulfonic acid, an arom. vinyl compd. such as styrene and acrylic acid, etc., added to facilitate the progress of polymn. is adjusted to the acidic region of 3-6pH. A precondensate of melamine-formaldehyde resin such as a precondensate of methylated methylol melamine is added to the aq. soln. and they are stirred at a constant temp. and cooled to obtain an opal white dispersion liq. contg. microcapsules. The microcapsules have superior heat, moisture and solvent resistances and useful for printing ink, pressure sensitive copying paper, etc. |
