| 摘要 |
A catalyst composition, suitable for the ambient temperature curing of polysulphide rubbers, comprises zinc carbonate, an organic sulphur-containing accelerator containing a disulphide linkage (e.g. a thiazole, thiuram or dithiocarbamate), and a sulphur/amine complex. The composition preferably contains from 15 to 90% by weight, based on the weight of zinc carbonate, of the organic accelerator and the sulphur/amine complex is preferably a sulphur/dialkylamine complex, the weight ratio of sulphur to amine in the sulphur/amine complex preferably being from 20:1 to 5:1 and the sulphur/amine complex preferably being present in the composition in an amount of from 0.2 to 8% by weight, based on the weight of zinc carbonate. The invention also provides an ambient temperature curable composition comprising a polysulphide rubber together with a curing composition as defined above, preferably containing from 15 to 75% by weight of zinc carbonate, based on the weight of polysulphide rubber; and containing a total of from 50 to 120% by weight, based on the weight of polysulphide rubber, of zinc carbonate, organic accelerator and sulphur/amine complex. |
