| 摘要 |
The sealing and wedging masses (2b) for rail tracks (1) have binders (2a) with a copolymer epoxy-urethane-urea resin base. The binders are obtained from the following components: an unmodified fluid epoxy resin with an epoxide index between 0.50 and 0.55, a linear pre-polymer polyether-polyurethane with small hidden branches of isocyanates, a strong diamine able to harden or co-polymerise the epoxy resin and the isocyanate pre-polymer groups in order to give, in the final stage, an epoxy-urethane-urea copolymer. The diamines are chosen from cyclo-aliphatics, notably 3-3' dimethyl 4-4' dicyclohexyl methane diamine and isophorone diamine and an aliphatic diamine. The masses also comprise dry granular minerals and rolled uncut grains chosen from silica sands of between 0.1 mm and 0.2 mm, quartz granules, gravel of between 2 mm and 4 mm and corundum of different granular sizes. The binders are placed in location by rapid injection under pressure in the spaces requiring filling (7), after first subjecting them to moderate heating. |
