Heat resistant insulating foam prodn. with high compression strength - from novolak and highly aromatic coal by=product

摘要

Foam prodn. from bituminous compsns., novolaks and opt. modifiers is carried out by simultaneous foaming and cure at 150-210 deg.C, with addn. of novolak crosslinkers and blowing agents if necessary. The novel feature is that highly aromatic coal by-prods. obtd. by disintegration of coal of similar prods., are used. Foams resistant to pressure and high temp. and useful for insulation can be produced without recourse to the use of raw materials based on mineral oil. Pref. a highly aromatic pitch-like by-prod. is used, which is obtd. by disintegrating coal or similar raw materials with aromatised residues from petroleum cracking fractions in combination with aromatic mixts. originating from coal, with an average b.pt. of over 350 deg.C as complementary solvent, opt. with addn. of other solvents originating from petrol or coal. The coal disintegration prods. are reacted with modified novolaks from phenol, cresols or xylenols or their mixts., pure carbazole or carbazole fractions from coal tar distn., and aldehydes, esp. HCCO, in a molar ratio of carbazole/phenol of 1:2-5 and of carbazole/phenol to aldehyde of 1:0.5-1.5 at 150- 210 deg.C and foamed and cured with addn. of hexamethylenetetramine, with intensive stirring.