| 摘要 |
<p>1,227,086. Laminates. SOC. CHIMIQUE DES CHARBONNAGES. 2 July, 1969 [2 July, 1969], No. 33481/69. Heading B5N. [Also in Division C3] Laminates are prepared from glass fabrics and resinous compositions obtaining by heating an epoxy resin with a polycarboxylic acid anhydride in a polar solvent until the mixture is completely dissolved. Reaction is terminated by stopping the heating; the solvent may then be removed and the resin dissolved in a ketone or ester. From 10-150 parts of polar solvent, e.g. dimethylsulphoxide, dimethylformamide, acrylonitrile or acetonitrile, are used per 100 parts by wt. of epoxy resin. Up to 0À5 mol. of anhydride may be used per epoxy group in the resin. Suitable anhydrides are the dianhydrides of benzophenonetetracarboxylic acid and cyclopentanedicarboxylic acid. In an example a 6-sheet laminate is made by pressing for 1¢ hours at 160‹ C. under 75 kg./sq. cm.</p> |
