Low-smoke halogen-free flame-retardant cable material with good charring property, preparation method thereof and cable

Abstract

The invention discloses a low-smoke halogen-free flame-retardant cable material with good charring property, a preparation method thereof and a cable. The low-smoke halogen-free flame-retardant cablematerial comprises the following components in parts by weight: 40 parts of matrix resin, 50-60 parts of a flame retardant, 0.5-1.5 parts of an antioxidant and 1-5 parts of a lubricant. Wherein the matrix resin is composed of EVA and a compatilizer, and the VA content in the EVA is 0.28; wherein the flame retardant comprises the following components in parts by weight: 35-40 parts of type II ammonium polyphosphate, 7-10 parts of cellulose nanofibers, 1-5 parts of a dispersing agent, 5-10 parts of layered graphite and 35-50 parts of a solvent, and the crystallinity of the cellulose nanofibers is greater than or equal to 75%. According to the low-smoke halogen-free flame-retardant cable material disclosed by the invention, the compatibility of the base material and the flame retardant is good, the charring is compact, the charring performance is good, and excellent mechanical properties and flame retardance are both considered.

Description

technical field [0001] The invention relates to the technical field of cable materials, in particular to a low-smoke, halogen-free, flame-retardant cable material with good char-forming properties, a preparation method thereof and a cable. Background technique [0002] With people's awareness of environmental protection and the environmental protection requirements of the cable industry, the demand for low-smoke, halogen-free, flame-retardant polyolefin cable materials is gradually increasing. EVA (ethylene-vinyl acetate copolymer) is a halogen-free polar polymer, which is considered to be the most promising sheathing material, oxygen barrier material and shielding material due to its good electrical properties, physical properties and processing properties one of the bases. However, the flame retardant performance of EVA is not excellent. Most of the current EVA flame retardant systems use inorganic flame retardants such as metal hydroxides and graphite as fillers, and rel...

AI Technical Summary

Problems solved by technology

However, the flame retardant performance of EVA is not excellent. Most of the current EVA flame retardant systems use inorganic flame retardants such as metal hydroxides and graphite as fillers, and relatively efficient intumescent flame retardants such as phosphorus-nitrogen fillers are also used. This makes the flame retardant performance of EVA significantly improved

[0003] However, after adding flame-retardant fillers, while the flame-retardant performance of EVA is improved, there are also obvious defects, and this defect is unavoidable

Since EVA itself has a polar linear chain molecule, and general flame retardants are non-polar or weakly polar, this leads to poor compatibility between the substrate and the flame retardant, and the mechanical properties are also reduced.

In addition to compatibility issues, the carbonization effect of cable materials is also difficult. Inorganic metal hydroxide itself does not contain carbon, and the amount of remaining carbon residue is small. Although graphite has a high carbon content, it is not ideal as a flame retardant alone. , and due to the size effect, the smaller the particle size, the worse the flame retardant effect

As for the high-efficiency phosphorus-nitrogen flame retardant, in addition to being easy to absorb moisture, its char formation effect is not ideal, and the continuity and compactness of the char layer cannot be guaranteed.