摘要 |
A salt of a Periodic Group 1A cation or a tertiary or quaternary ammonium cation and an anion of a strong acid is used in a process for manufacturing minute capsules by polycondensing melamine formaldehyde capsule wall precursor material in an acidic aqueous manufacturing vehicle also containing a negatively charged polymeric carboxyl-substituted polyelectrolyte material. The resulting capsules may be used in pressure-sensitive copying materials. |