Formaldehyde → Melamine formaldehyde

Participants

Reaction Conditions

Reaction Steps

37.5 parts of 40% liquid A (dispersion of dye precursor) and 100 parts of 40% liquid B (co-dispersion of color developer-sensitizer) obtained in the above (1) were mixed with each other until a homogeneous mixture was obtained. 137.5 parts of the mixture of liquor A and liquor B was gradually added with 110 parts of an 5% aqueous solution of sodium salt of styrene-maleic anhydride copolymer adjusted to pH 4.0 with stirring. Stirring was carried out for about 30 minutes to obtain agglomerates having an average particle diameter of 10 μm and it was simultaneously confirmed that the agglomerates were emulsified and dispersed. Separately, a mixture comprising 15 parts of melamine, 37.5 parts of a 37% aqueous formaldehyde solution and 97.5 parts of water was adjusted to pH 9.0 with sodium hydroxide and then was heated at 60° C. with stirring to perform dissolution to obtain 150 parts of a transparent melamine-formaldehyde precondensate.

Provenance & Evidence