| 摘要 |
<p>A method is disclosed of preparing a bituminous composition from an anionic bituminous (bitumen or bitumen plus a rubber) emulsion, which composition is suitable for coatings for sealing, water-proofing and insulating purposes. The composition has a controlled and known pot-life, acceptable drying time and good resistance to re-emulsification. The method is characterised by intimately mixing the emulsion with an amount of an emulsion-breaking accelerator, the composition and quantity of which are such as initially to delay release of cations and thereafter release cations in a controlled, uniform, rate for reaction with the anionic emulsifier(s) of the emulsion. Further essential properties of the accelerator employed are that it neither materially alters the pH value of the emulsion nor binds any substantial quantity of water. Calcium sulphate dihydrate in a water-insoluble hydrocarbon fraction, and employed at 1 to 2% treat rate, is a preferred accelerator. An assembly of units containing various constituents required to produce the bituminous coating composition is also described.</p> |
