Ultraviolet deep-crosslinked expansion flame-retardant polyolefine cable material, and preparation method of insulating or jacket layer thereof

The invention relates to an ultraviolet deep-crosslinked expansion phosphorus-nitrogen flame-retardant polyolefine cable material, and a preparation method of an insulating or jacket layer thereof. Polyethylene or graft-modified polyethylene and/or ethylene-vinyl acetate or graft-modified copolymer thereof are used as base materials, surface-modified expansion phosphorus-nitrogen halogen-free flame retardant, cation photoinitiator, free-radical photoinitiator, polyfunctional group crosslinking agent and composite antioxidant are added, and flame-retardant synergist, synergistic smoke suppressor and processing assistant are matched to obtain the ultraviolet deep-crosslinked expansion phosphorus-nitrogen flame-retardant polyolefine cable material. The preparation method comprises the following steps: proportionally and evenly mixing the materials to obtain granules, extruding to obtain an optical crosslinked expansion flame-retardant wire cable insulating layer or jacket layer, and radiating by a specific ultraviolet source for several seconds to obtain the deep-crosslinked insulating layer or jacket layer. The new material and new technology have the advantages of low investment required for crosslinking equipment, simple technique, energy saving, environmental protection, high production efficiency, low cost and good product quality, and can be widely used for manufacturing rail transportation cables, various mechanical wires, indoor assembly wires and the like.