Formaldehyde → Melamine formaldehyde

Participants

Reaction Conditions

Reaction Steps

A styrene-maleic anhydride copolymer heated at 60° C. and a small amount of sodium hydroxide were dissolved in water, whereby there was prepared an aqueous solution of pH 4.0 containing 5% of a styrene-maleic anhydride copolymer and a small amount of sodium hydroxide. In 100 parts of this solution was dispersed 50 parts of Color Index Number "Disperse Yellow 54" (brand name: Kayaset Yellow A.G, manufactured by NIPPON KAYAKU) and an emulsion was prepared. 3 Parts of melamine, 7.5 parts of a 37% aqueous formaldehyde solution, 40 parts of water and a slight amount of sodium hydroxide were mixed. The mixture was heated to 60° C. In 15 min, the mixture became transparent and a melamine-formalin precondensate was obtained. This precondensate was added to the above prepared emulsion. The mixture was stirred at 60° C. (liquid temperature) for 3 hr, whereby encapsulation was completed.

Provenance & Evidence