Liq. acidic phenolic resin condensn. prods. - useful as curing agents for thermosetting resins, made by reacting a sulphonated phenol aldehyde resin, urea and formaldehyde

摘要

Liq. phenolic resins with poor solubility in water are useful as curing agents for thermosetting resins. The resins have a liq. consistency at +10 to -30 degrees C and are made by condensing (a) a sulphonated cpd. with a liq. consistency over 25 degrees C, made by sulphonating 1 mol. phenol and 0.05-0.29 mol aldehyde; (b) urea or its derivs. and (c) formaldehyde in a mol. ratio (a):(b):(c) of 1:(0.1-1.0): (0.1-1.0). The prods. are viscous, rose to cherry red liquids (1-100 p at 20 degrees C) with a weak phenolic smell and an acid value of 50-350 mg KOH/g. They are easily soluble in alcohol, acetone and DMF. The liq. consistency is retained at +10 to -30 degrees C. The resins are formed at relatively low temps. so that decomposition of the urea during the process is avoided. Resins are useful as (room temp.) curing agents for phenolic, urea and melamine aldehyde resins, furan resins, etc., and esp. for foamed resin insulation materials.