Thermistor composite material with high sensitivity and high-temperature resistance, and preparation method thereof

Abstract

The invention discloses a thermistor composite material with high sensitivity and high-temperature resistance. The thermistor composite material comprises the following raw materials by weight: 5 to 7 parts of graphene, 45 to 55 parts of a polymer material, 3 to 7 parts of a rare earth mixture, 15 to 25 parts of a conductive auxiliary material, 3 to 5 parts of a coupling agent, 6 to 8 parts of a metal oxide filling material, 20 to 30 parts of acrylic resin, 3 to 5 parts of a cross-linking aid and 2 to 4 parts of a performance improving aid. The thermistor composite material provided by the invention is low in initial resistance, fast in response speed and excellent in correlation between temperature and resistance, maintains good stability and reliability in severe environments like high temperature and has substantially prolonged service life; Meanwhile, a preparation method for the thermistor composite material uses easily available raw materials, is low in cost and simple in process, and has high practical value and good application prospects.

Description

technical field [0001] The invention relates to the technical field of resistance materials, in particular to a high-sensitivity and high-temperature-resistant thermistor composite material and a preparation method thereof. Background technique [0002] Polymer composite materials with a positive temperature coefficient (PTC) are widely used in computers and their peripheral equipment, mobile phones, battery packs, telecommunication and network equipment, transformers, industrial control equipment, automobiles and other electronic products to play a role in overcurrent Or the role of over-temperature protection. PTC polymer composite material is a heat-sensitive material whose resistance value increases with the increase of temperature, that is, the resistance or resistivity of the material remains basically unchanged or only slightly changes within a certain temperature range, while When the temperature reaches a specific transition point temperature of the material, the r...

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Problems solved by technology

The PTC polymer composite material filled with carbon black has the characteristics of adjustable electrical conductivity in a wide range, easy molding, and low cost; however, the existing problems are high room temperature resistivity and poor stability of the PTC effect, resulting in PTC strength and output. The power attenuation is too fast, the leakage current is large after protection, etc.

However, in the PTC polymer composite material with metal particles as conductive fillers, since the metal particles are always rigid particles during the phase transition process of PTC temperature rise, no phase transition occurs, resulting in a more serious negative temperature resistance effect (NTC) during the continuous temperature rise process. ;The emergence of NTC phenomenon not only causes irreversible changes in the electrical properties of PTC materials, but also causes failure due to high temperature of the materials during the use of the materials, and even ignites and burns