Thermally insulating materials containing binder based on phenol formaldehyde resin and their preparation

摘要

The invention concerns an insulating product based on mineral wool sized with a binder based on phenol-formaldehyde resin, wherein the binder comprises in a mixture: 60 to 90 parts by weight of a phenol-formaldehyde resol having a free formaldehyde rate not more than 25 wt. % relative to the resin dry weight and a proportion of free phenol not more than 2.5 wt. % relative to the resin dry weight obtained by condensation in basic medium of phenol (P) and of formaldehyde (F) in a F/P mol ratio of the order of 2.5 to 4 until the condensation product neutralised by sulphuric acid has a dilutability in water higher than 500 % and not more than 1500 %; 10 to 40 parts of urea. Said sizing composition is useful for making insulating products reducing ammonia emissions on the production line.