Process for preparing phenolic binder

摘要

A phenolic binder for glass fibers is prepared using an aqueous mixture including a phenol-formaldehyde resole resin, modified with urea in the presence of ammonia. The urea and ammonia are added after the basic mixture including the resole resin has been neutralized. The urea-modified resole resin shows greater stability than urea-modified resins prepared without ammonia.