| 摘要 |
<p>1444647 Fluoroelastomer E I DU PONT DE NEMOURS & CO 19 Aug 1974 [22 Aug 1973] 36456/74 Heading C3P A vulcanizable fluoroelastomer which is a copolymer containing interpolymerized units of (A) 50-65 mole per cent of tetrafluoroethylene, (B) 5-26 mole per cent of vinylidene fluoride and (C) 20-45 mole per cent of at least one of the olefin components: (1) propylene, (2) butene-1, (3) a mixture of 0À1-50 mole per cent of ethylene or isobutylene and 99À9-50 mole per cent of propylene or butene-1 and (4) a mixture of about 50 mole per cent of ethylene and 50 mole per cent of isobutylene. A composition which can be vulcanized by heating in two stages (a) at 149-204‹ C. for 1-60 minutes and then (b) at 180-300‹ C. for 1-48 hours comprises the fluoroelastomer as defined above and a diamine or diamine carbamate which acts as a cross-linking agent for the fluoroelastomer and a cross-linking accelerator. The accelerator may be a quaternary ammonium componnd, a quaternary phosphonium compound, a penta-substituted guanidine or salt thereof, a trisubstituted amidine, a cyclic polyether or an open chain polyether.</p> |
