Лако-красочные материалы — производство

Formaldehyde reacts with phenol by electrophilic substitution at the 2-, 4- and 6-positions of phenol and will subsequently condense, forming a densely cross-linked network. This reaction can be cata­lyzed by acid as well as base catalysts. The nature of the product obtained is largely dependent on the type of phenol, the molar ratio of formaldehyde to phenol (f:p) and the catalyst used. Phenolic resins are mainly divided into two broad classes: resoles and novolacs.