Formaldehyde → Melamine formaldehyde

Participants

Reaction Conditions

Reaction Steps

Independently, to 13.2 g of melamine were added 21.6 g of 37% aqueous solution of formaldehyde and 70 g of distilled water, and the resulting mixture was stirred at 60° C. for 30 minutes to obtain a transparent melamine-formaldehyde precondensate. To 40 g of the precondensate was added the above-prepared W/O/W emulsion, and the resulting mixture was adjusted to pH 6.0 using 20% aqueous solution of phosphoric acid under stirring. The mixture was then heated to 60° C. and stirred for 120 minutes. Further, to the mixture was added 16 g of a 40% aqueous solution of urea to remove formaldehyde remaining in the microcapsule dispersion, and the mixture was adjusted to pH 3.5 using 20% aqueous solution of phosphoric acid. After the reaction was completed, the mixture was adjusted to pH 6.5 using 10% aqueous solution of sodium hydroxide, and then cooled. Thus, a light-sensitive microcapsule dispersion (A) containing microcapsules having a melamine-formaldehyde resin shell was obtained.

Provenance & Evidence