| 摘要 |
<p>Stable aqueous dispersions of formo-phenolic resols without solvent whose free formol content is less than 0.1 % are obtained by condensing formaldehyde and phenols in the presence of a catalyst, and by the formation of an aqueous in-situ dispersion of the resin formed in the presence of a protective colloid, the process involving the addition of ammonia, carried out only after the free formaldehyde content, which varies during the condensation phase, has stabilized at a constant level.</p> |
