VERFAHREN ZUR HERSTELLUNG SCHRUMPFARMER FORMKOERPER AUF POLYESTERBASIS.

摘要

Low-shrinkage, low-delay mouldings (I) are mfd. by hardening of unsatd. polyester moulding materials (II) and processing at a mould temp. of below 100 deg.C. Resin component of (II) comprises 20-70 wt.% unsatd. polyester (III) of mol.wt. factor 210-450, 20-55 wt.% comonomer (IV) and 8-25 wt.% shrinkage reducing polymer (V), which is a polyester-urethane contg. no polymerisable double bonds and with 0.05-0.8 equiv. urethane gps. per 100 g. Pref. (III) has mol.wt. factor 235-420; (V) has 0.1-0.3 equiv. urethane gps. per 100 g; pref. moulding temp. is 20-95(esp. pref. 40-80) deg.C. (III) is prepd. from diols such as propanediol, Bisphenols, etc. with a mixt. of unsatd. acid such as maleic or fumaric acid and other diacids such as isophthalic, adipic acid, etc.; pref. (IV) is styrene (opt. substd.); (V) is mfd. from polyol of pref. mol. wt. 1000-2500 (condensation prods. of diols and diacids) and polyisocyanate (pref. TDI, DMDI).