摘要 |
Polyethylene compsns. for extrusion of sheet and tubes with low surface resistivity, consist of 92.5-85 wt.% PE and 7.5-15% carbon black with surface area (BET) 300-1500 m2/g, oil absorption 2.5-5.k ml/g. volatile content 0.1-6 wt.%, pH 7-10 and ash content 0.5-5 wt.%, together with usual additives e.g. stabilisers, process adds or lubricants. The compsns. are used in anti-static applicns in atmospheres with explosion hazards, e.g. in mining. Surface resistivity below 109 ohms is obtd. by addn. of only 7.5-8% of black, with less adverse effect or mechanical properties, e.g. impact resistance, than occurs with known conductive blacks. |