Ultraviolet crosslinked expansion type flame-retardant polyolefin cable insulation sheath material and preparation thereof

Abstract

The invention discloses an insulating and sheathing material of ultraviolet light crosslinking expanding type phosphorus nitrogen flaming resistance polyolefine cables and a preparation method thereof. The invention is characterized in that polyethylene/PEMA and/or ethylene vinyl acetate or maleic anhydride grafted ethylene vinyl acetate or acid amide grafted ethylene vinyl acetate copolymer are taken as base, added with expanding type phosphorus nitrogen halogen-free flame retardants, light trigger, polyfunctional group cross linker and chemical inhibitor and matched with flaming retardant synergistic agent, antismoke agent and processing aid, and then squeezed out and pelleted into photo-crosslinking flame retardant cable materials; and then the flame retardant cable materials are melted and extruded on a cable conductor wire core and clad into an insulating layer and a sheathing layer; hereupon the ultraviolet light irradiation crosslinking is carried on the insulating layer or the sheathing layer. Via detecting, the oxygen index of the insulating layer or the sheathing layer is larger than 30%, the vertical flaming experiment passes through UL-94 V0 level, the tensile strength is larger than 12Mpa, the elongation at break is larger than 350%, and the electric volume resistivity is larger than 8*10 omega.cm.

Description

technical field [0001] The invention belongs to the technical field of preparation methods of polyolefin cable materials, and in particular relates to insulation layer and sheath layer materials of ultraviolet light crosslinking expansion type phosphorus nitrogen flame-retardant polyolefin cables and a preparation method thereof. Background technique [0002] Cross-linked polyolefin materials have the characteristics of excellent electrical properties, high long-term use temperature, corrosion resistance, good pressure and heat resistance, and high mechanical strength, and are being increasingly used in the manufacture of cross-linked wires and cables. However, the main disadvantage of cross-linked polyolefin materials is that they are easy to catch fire and cause fires. At present, the most commonly used halogen-containing flame-retardant polyolefin materials will release a large amount of smoke and toxic, corrosive hydrogen halide and other gases when burning, which hinder...

AI Technical Summary

Problems solved by technology

However, there have been no reports about cross-linked intumescent phosphorus-nitrogen flame-retardant polyolefin materials, and this is because the above-mentioned several main cross-linking methods have certain limitations on the preparation of cross-linked intumescent phosphorus-nitrogen flame-retardant polyolefin materials. due to shortcomings or problems

High-energy radiation cross-linking equipment requires high investment, complicated operation and maintenance, and strict protection requirements. Even if it can be applied to cross-linked intumescent phosphorus-nitrogen flame-retardant polyolefin materials, the cost of the product is high, and because the irradiation surface of electron beam rays is very small , it is difficult to apply to the cross-linking of thick cables, and the high energy of the electron beam will also destroy the structure of the material to a certain extent, resulting in a decrease in related properties; chemical cross-linking of peroxide requires high temperature and high pressure conditions, and high temperature will make phosphorus Nitrogen flame retardants decompose ahead of time, and high pressure makes it difficult to swell phosphorus-nitrogen flame retardants; silane cross-linking requires hydrolysis to complete cross-linking, while phosphorus-nitrogen flame retardants are very easy to absorb water and degrade, thereby reducing the material Flame retardant and electrical properties