Polyolefin conductive polymer with positive temperature coefficient

Abstract

The invention relates to a modification of the conductive polymer with positive temperature coefficient. The modification of the conductive polymer with positive temperature coefficient is characterized in that the basic composition adopts the weight percentage of polyethylene with high density and or low density which occupies 30 percent to 60 percent, the weight percentage of ethylene propylene diene monomer which occupies 10 percent to 30 percent, the weight percentage of electric carbon black which occupies 10 percent to 25 percent, the weight percentage of deca-brominated diphenyl ether which occupies 10 percent to 20 percent and the weight percentage of plastic stabilizer which occupies 5 percent to 10 percent. Because the ethylene propylene diene monomer is added into the polyolefin base material, under the precondition that PTC characteristic is not changed, the toughness of the polymer is enhanced, the crack is not generated in the low-temperature bending test (20 DEG C minus, 4 hours), the cold resistant performance is improved, no crack is generated under normal operation in the cold area with the temperature higher than 10 DEG C minus, the PTC characteristic is stable, and the power and the resistance are not obviously decreased.

Description

technical field [0001] The invention is an improvement on the positive temperature coefficient conductive polymer, and particularly relates to a positive temperature coefficient polyolefin conductive polymer which can be used in a cold region not lower than -10°C. Background technique [0002] Positive temperature coefficient conductive polymer, one use is as a self-limiting temperature heating cable (cable) heating element, used for heat tracing of pipelines, valves, and solar water heater pipelines in petroleum, chemical, thermal power plants, etc., ground heating, cold-proof clothing, heating Hand heating, heat preservation, etc. In the prior art, positive temperature coefficient conductive polymers mostly use relatively low-priced polyolefin and graphite as the base material, plus some additives, such as the low-temperature grade, positive temperature coefficient of resistance flame-retardant resin composition disclosed in Chinese patent CN1699510 , composed of 30-60% l...

AI Technical Summary

Problems solved by technology

However, one disadvantage of this type of positive temperature coefficient conductive polymer is that in cold regions such as minus 5°C, the polymer will harden or even crack, so its cold resistance is poor at low temperatures and cannot meet the requirements of use.