| 摘要 |
<p>A composite is produced by arranging several different materials, one of which is a material with oriented reinforcement, pre-impregnated with a resin and moulding at raised temp. for a time sufficient to harden the resin and ensure bonding between the components. The components, including the resin, are arranged at the same time, before raising the temp., i.e. the resin is not injected separately after the other components have been arranged. The resin is a modified polyester-polyurethane prepd. by reacting (1) a 1st component comprising (A) a polyisocyanate with functionality 2-3, and (B) a peroxide able to initiate free radical polymerisation, in proportion such that (B)/(A) + (B) is 0.5-4 wt.%, with (2) a 2nd component comprising (a) a polyester polyol obtd. from an ethylenically unsatd. diacid or anhydride and a polyhydric alcohol, in molar ratio of alcohol:acid of 1.3-2.0, (b) an ethylenically unsatd. monomer in proportion such that (b)/(a)+(b) is 10-50 wt.%, (c) 0-4%, w.r .t. the 2nd component, of a promoter of the decomposition of the peroxide initiator at 20 degrees C, (d) 0-4%, w.r.t. the 2nd component, of a catalyst for the isocyanate-alcohol reaction, and (e) a hydroxylated (alk)acrylate in proportion such that (e)/(a)+(e) is 0.1-35 wt.%. The molar ratio between the NCO functions in (1) : the sum of the OH functions in (2) is 0.7-1.1.</p> |
