Formaldehyde → Melamine formaldehyde

Participants

Reaction Conditions

Reaction Steps

Thus, 80 parts of a solution of 3.5 parts of crystal violet lactone (CVL) and 1.5 parts of benzoyl leucomethylene blue (BLMB) in 1,1-diphenylethane was added to 100 parts of 5% aqueous solution of styrenemaleic anhydride copolymer containing a small quantity of sodium hdyroxide and having a pH value of 4.0, and emulsified to give an emulsion. On the other hand, a mixture comprising 10 parts of melamine, 25 parts of 37% aqueous solution of formaldehyde and 65 parts of water was adjusted to pH 9.0 with sodium hydroxide and heated to 60° C. The mixture became transparent in 15 minutes, and there was obtained a melamine-formaldehyde pre-condensate. The pre-condensate was added to the above-mentioned emulsion, the temperature was adjusted to 60° C. and stirring was continued. The formation of capsules was confirmed in 30 minutes, after which the mixture was cooled to room temperature. The microcapsule-containing dispersion thus obtained had a solid content of about 45%.

Provenance & Evidence