Halogen-free flame-retardant 1E-class double-layer thermal shrinkable pipe for nuclear power station

Abstract

Provided is a halogen-free flame-retardant 1E-class double-layer thermal shrinkable pipe for a nuclear power station. The halogen-free flame-retardant 1E-class double-layer thermal shrinkable pipe comprises an outer layer and an inner layer. The outer layer is a thermal shrinkable layer and the inner layer is a hot melt adhesive layer. The outer layer comprises, by weight, 5 to 10 parts of ethylene-vinyl acetate copolymer, 60 to 80 parts of ethylene-methyl acrylate copolymer, 20 to 40 parts of ethylene propylene rubber, 6 to 12 parts of microencapsulated red phosphorus, 40 to 55 parts of magnesium hydroxide, 8 to 15 parts of boron nitride, 4 to 8 parts of complex antioxidant, and 1 to 2 parts of light stabilizer. The inner layer comprises, by weight, 100 parts of ethylene-methyl acrylate copolymer, 8 to 15 parts of dysprosium oxide, 4 to 8 parts of complex antioxidant, and 1 to 2 parts of light stabilizer. The halogen-free flame-retardant 1E-class double-layer thermal shrinkable pipe for the nuclear power station is excellent in waterproof and moisture-proof performance, excellent in heat resistance, excellent in radiation resistance, and excellent in high-temperature high-pressure water vapor resistance, and has insulation performance and voltage resistance satisfying requirements.

Description

technical field [0001] The invention relates to a heat-shrinkable tube for nuclear power plants. Background technique [0002] Nuclear power belongs to clean energy and is a priority industry in my country. In 2014, China operated 22 nuclear power units with an installed capacity of 20,296,580 kilowatts, and there are 26 nuclear power units under construction with a capacity of about 28 million kilowatts. [0003] The 1E-level double-layer heat-shrinkable tubes used in nuclear power plants are installed in the containment shell, which can complete their specified functions not only under normal environmental conditions, but also in the environment and after the accident. According to the requirements of the third generation of nuclear power, the thermal life of 1E-level double-layer heat shrinkable tubes used in nuclear power plants must reach 90 °C for 60 years, after 2400KGy radiation aging and the LOCA experiment with a maximum temperature of 218 °C and a maximum pressur...

AI Technical Summary

Problems solved by technology

[0004] At present, it is clearly required that the 1E-grade double-layer heat-shrinkable tubes for nuclear power plants cannot contain halogens, but the 1E-grade double-layer heat-shrinkable tubes for nuclear power plants on the market contain halogens, which do not meet the requirements of nuclear power plants. The market urgently needs 1E-grade halogen-free flame-retardant nuclear power plants. Double layer heat shrink tubing