PURPOSE: To prepare the titled composition giving a cable insulation material having excellent electrical properties and high expansion ratio by a conventional extruder, by compounding a specific base polyethylene resin with a mixture of azodicarbonamide and a specific compound as a foaming agent.
CONSTITUTION: The objective composition is prepared by compounding (A) 100pts.wt. of a low-density polyethylene having a melt index of 1W7 or a mixture of the low-density polyethylene and a high-density polyethylene with (B) 1W5pts.wt. of a foaming agent prepared by mixing (i) azodicarbonamide with (ii) p'-oxybis(benzenesulfonylhydrazide) at a weight ratio of 1:1W4:1. It is preferable to add 10W100wt%, based on the component (i), of a foaming assistant (perferably zinc stearate) to the component (i) to lower the decomposition temperature of the component (i) to a level matched with the processing temperature of the component (A).
SHIMIZU OSAMU
KATOU MASAHIRO
| JP43030261A | ||||
| JPS5821432A | 1983-02-08 |