| 摘要 |
Method for the manufacture of a colourless or light-coloured phenolic polymer network using upon curing a phenolic resin emulsion and/or dispersion, in which an aldehyde, a phenolic compound and an alkaline catalyst are allowed to react at a temperature of 40-(100 DEG C until a desired degree of condensation is achieved, and the pH of the resin is adjusted to a value below 9 using an acid in the presence of a surface active agent or a mixture of surface active agents at a temperature below the boiling point and a phenolic resin emulsion and/or dispersion is obtained and used as a precursor to give a colourless or light-coloured polymer network when cured. The phenolic resin emulsion and/or dispersion may optionally be spray-dried. |
