Formaldehyde → Melamine formaldehyde

Participants

Reaction Steps

In 100 parts of a 5% aqueous solution (pH 4.0) of a small quantity of sodium hydroxide together with styrene-maleic anhydride copolymer heated at 60° C. were dispersion-emulsified 80 parts of a color developer dispersion (previously pulverized and dispersed in a ball mill for 48 hours) obtained by dispersing 45 parts of 4,4'-isopropylidenediphenol in 55 parts of light oil to prepare an emulsion having an emulsion particle size of about 4 to 5 μm. Separately, a mixture of 10 parts of melamine, 25 parts of a 37% formaldehyde aqueous solution, 65 parts of water and a small quantity of sodium hydroxide was heated to 60° C. The mixture became transparent 15 minutes after to obtain the melamine-formaldehyde precondensate. This precondensate was added to the emulsion. Stirring was continued at a liquid temperature of 60° C. for 3 hours to complete microencapsulation.

Provenance & Evidence