| 摘要 |
<p>The flame resistance imparted to (inter alia) polypropylene by a combination of basic bismuth carbonate and suitably chlorinated paraffin wax, according to U.K. Patent 1,516,548, is extended to impact-resistant compositions of thermoplastic propylene-ethylene block copolymers compounded with a minor proportion of elastomeric ethylene-propylene copolymer, by the additional presence of a defined triazine compound and a defined brominated organic compound. The former, present to the extent of 0.3-1.3% w/w on the total composition, may be melamine, ammeline, ammelide, acetoguanamine, benzoguanamine or isocyanuric acid. The brominated organic compound, present in an amount of 0.5-10% w/w, may be penta-,deca- or octa- bromodiphenyl oxide, 1.2-bis (2.4.6tribromo-phenoxy)ethane, pentabromophenol, pentabromotoluene or ethyl pentabromobenzene. A typical composition is 90.5 parts of block copolymer containing 20% of the eloastomer, 1 part of bismuth subcarbonate, 1 part of melamine, 3.5 parts of chlorinated paraffin wax (70% chlorine), 3.5 parts of decabromodiphenyl oxide together with 0.5 parts of dibutyltin maleate (anti-acid stabilizer).</p> |
