| 摘要 |
Hardenable, polyester resins are a mixt. of, by wt. 20-80 (40-70)% unsaturated polyester (A), 80-20 (pref. 60-30)% aliphatic vinyl monomer (B), copolymerisable with (A) and free from aromatic components, and >25% (w.r.t. total A +B + C wt.) hydrated Al2O3 as pigment (C). (A) is prepd. by polycondensation of (1) an organic polyol having functionality >=2 and (2) an organic polycarboxylic acid having functionality >=2 and contg. >=1 alpha,beta-ethylenically unsaturated polycarboxylic acid. Equiv. ratio of alpha,beta-ethylenically unsaturated polycarboxylic acid to all other polycarboxylic acid components fo polyester is >1:1 (>2.5:1). Hardened prods. can be used as mouldings, laminates or coatings, e.g. as car, aeroplane, or boat components, heavy vehicle panels, armatures, pipes and conduits. Polyester resins can be mixed with 10-70 wt.% glass fibres. Articles of completely hardened resin are strong, burn with difficulty and develop only little smoke when exposed to an open flame, i.e. generate low smoke density e.g. 200, partic. 100. Hydrated alumina increases O2-index without affecting smoke density. |
