Polyurethane prepn. from polyols and isocyanates - catalysed by mixt. of heavy metal salt and alkali or alkaline earth metal salt of organic acids

摘要

Catalyst for use in 2-component (cyclo)aliphatic polyurethane prodn. from isocyanates and polyols. Catalyst is a mixt. of 0.005-0.5 wt.% heavy metal salts of organic acids with 0.05-5 wt.% alkali(ne earth)metal salts of organic acids. Hardening takes place at a higher temp. esp. at 80-250 degrees C. Used e.g. for polyurethane lacquer prepn. Catalyst mixt. lengthens processing times at room temp. and shortens hardening cycle at higher temp. In an example, catalyst mixt. contg. 0.1% dibutyl Sn dilaurate and 2.3% Ba 2-ethyl hexoate was used for reacting (1) polycondensate of phthalic anhydride, trimethylol propane and hexanediol-1, 6 with (2) adduct of 3-isocyanatomethyl-3,5,5-trimethyl-cyclohexyl isocyanate with trimethylol propane, in toluene. Addn. of Ba octoate increased gelling time at 20 degrees C from 9.5-14 hrs. and reduced hardening time at 170 degrees C from 4-4.5 min. to 2.5-3 min.