| 摘要 |
<p>The invention provides resins suitable for solvent-based varnishes containing nitrocellulose, which resins are the reaction product of 1.5-2.5, preferably 1.75-2.25 moles of dicyclopentadiene per mole of alpha-beta unsaturated dicarboxylic acid, which resin has an average molecular weight of 600-900, an acid value of 70-100, a saponification index of 250-300, a bromine index of 60-100 and a softening point of 100-160 DEG C. The resins are prepared by initial reacting at 100 to 140 DEG C and subsequently at 175 to 250 DEG C. Preferably a mineral acid catalyst is used.</p> |
