PLANAR AND SPACE FORMATIONS FROM POLYOLEFINS, THEIR COPOLYMERS OR, IF NEED BE, MIXTURES

摘要

Plastic matters in difficult environments with high dustiness and a danger of explosion resulting from accumulation of static electricity must have semiconductive as well as self-extinguishing characteristics. Nevertheless, when the mixture is filled with substances carrying either of these qualities, the physical and mechanical characteristics of the product deteriorate. The new solution consists in the fact that surface and space systems of polyolefins and their copolymers, or eventually mixtures, composed of at least two layers, have one layer with a thickness of 10 to 90 percent of overall thickness of the product, containing from 73 to 88 percent by weight of polyolefin, from 5 to 10 percent by weight of antimony trioxide, from 5 to 10 percent by weight of vinyl chloride-propylene copolymer and other common admixtures like stabilising agents and toners, while this layer is on one or both sides covered with a layer containing from 80 to 93 percent by weight of polyolefin, from 5 to 15 percent by weight of high-surface soot, a mixture of alkylolamides of fatty acids of tallow in the amount of 2 to 5 percent by weight and possibly other common admixtures. The products show semiconductive as well as self-extinguishing properties and conserve good physical and mechanical characteristics.