| 摘要 |
<p>Prepd. from polychloroprene, phenolformaldehyde resin and chlorinated butyl rubber by mixing together an elastomer mixture and a solvent. Elastomer mixture consisting of 2-40% by weight (pref. 10-20%) of chlorinated butyl rubber and 98-60% polychloroprene. Phenolformaldehyde resin is product of alkali-catalysed reaction between a p-substituted phenol and HCHO. Solvent used is hydrocarbon particularly aromatic or halogenated hydrocarbon, and 5-30% by weight of the cement is a metal oxide partic. zinc. or magnesium oxides. Use of chlorinated butyl rubber in the cement increases the working ('open') time of the cement after application to a surface and produces better binding strength at high temperature.</p> |
