Formaldehyde → Melamine formaldehyde
Reaktionsgleichung
[Na].[N:2]1[C:9]([NH2:10])=[N:8][C:6]([NH2:7])=[N:5][C:3]=1[NH2:4].[CH2:11]=[O:12].[OH-].[Na+]>O>[CH2:11]=[O:12].[N:2]1[C:9]([NH2:10])=[N:8][C:6]([NH2:7])=[N:5][C:3]=1[NH2:4]Komponenten
6
[Na].[N:2]1[C:9]([NH2:10])=[N:8][C:6]([NH2:7])=[N:5][C:3]=1[NH2:4].[CH2:11]=[O:12].[OH-].[Na+]>O>[CH2:11]=[O:12].[N:2]1[C:9]([NH2:10])=[N:8][C:6]([NH2:7])=[N:5][C:3]=1[NH2:4]50 parts of 20% liquor A (dispersion of aromatic isocyanate compound) and 100 parts of 30% liquor B (co-dispersion of imino compound-sensitizer) obtained in the above (1) were mixed with each other until a homogeneous mixture was obtained. 150 parts of the mixture of liquor A and liquor B was gradually added with 120 parts of a 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 11.4 parts of melamine, 28.5 parts of a 37% aqueous formaldehyde solution and 74.1 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 114 parts of a transparent melamine-formaldehyde precondensate.
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