METHOD OF OBTAINING PHENOLIC BINDER, PHENOLIC BINDER AS SUCH AND METHOD OF MAKING PRODUCTS CONSISTING OF MINERAL FIBRES

摘要

Phenolic binder for inorganic fibres is prepared by means of an aqueous mixture containing a phenol-formaldehyde resole modified by urea in the presence of aqueous ammonia. The urea and the aqueous ammonia are added after the basic mixture containing the resole has been neutralised. The urea-modified resole exhibits a greater stability than urea-modified resins prepared in the absence of aqueous ammonia.