Lignin-modified binder mixts. prodn., useful for mfg. e.g. nonwoven textiles etc.

摘要

The binders (I) are produced by (i) pre-reacting low mol. wt. lignin obtd. by the organosolv process (L) with phenol in the wt. ratio (1:20)-(3:1) at 100-180 deg.C. then adjusting to acid pH and (ii) condensing at 60-120 deg.C. with 0.2-0.9 mol. formaldehyde per mol. phenol. Also claimed are lignin-phenol novolaks (I) obtd. by this process, and process for producing binder mixts. (II) by intensively mixing (I) with a phenolic novolak (III) in the wt. ratio (10:90)-(90:10) at 100-200 deg.C., then cooling, possibly drying, and finely milling or granulating the mixt.. Alternatively, (I) and (III) are mixed in the same. wt. ratio, pref. (30:70)-(70:30), in a solvent, esp. MeOH, EtOH, iso-PrOH, acetone, furfuryl alcohol or ethylene glycol. Pref. (III) are obtd. by condensn. of phenols, cresols and bisphenols with formaldehyde, and pref. solvent (see above) is furfuryl alcohol. Amt. of hardener (pref. HMTA) is 4-14 wt.%, and (II) can also contain lubricants, release agents, fillers and glass fibres etc..