Linear NTC thermosensitive polymer composite and preparation method thereof

Abstract

The invention provides a linear NTC thermosensitive polymer composite and a preparation method thereof. The preparation method comprises the steps that fluororubber, conducting particles and a coupling agent are proportioned by certain mass and then mixed and dissolved under the action of a solvent, dispersing under stirring and filtering are conducted, and finally a fluororubber-carbon black polymer composite similar to slurry is obtained, wherein the mass ratio x:y of the fluororubber to the conducting particles is (0.5-0.95):(0.05-0.5), and the quantity of the coupling agent accounts for 0.01%-0.5% of the total mass of the fluororubber and the conducting particles. The preparation method has the advantages of being low in preparation cost and simple in processing technology, and the composite prepared through the method has the advantages that the stability is good, and the resistance-temperature characteristics achieve a linear change law; thermosensitive components prepared from the composite are expected to replace Cd ceramic thermosensitive components to be applied to electronic industry.

Description

technical field [0001] The invention belongs to the field of linear negative temperature coefficient (NTC) heat-sensitive polymer composite materials, in particular to a linear NTC heat-sensitive polymer composite material with a small change rate of R (resistance) and TCR (temperature coefficient of resistance) and a preparation method thereof. Background technique [0002] Most heat-sensitive components are made of heat-sensitive ceramic materials and polymer composite materials. Their working principle is to use the resistivity of heat-sensitive ceramics and heat-sensitive polymer composite materials to change with temperature. Among them, most heat-sensitive ceramic materials are nonlinear NTC (Negative Temperature Coefficient) heat-sensitive materials, and their temperature coefficient of resistance is relatively large, generally -2% to -6% / °C; while there are few studies on linear NTC ceramic heat-sensitive materials, The currently reported linear NTC materials are mai...

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Problems solved by technology

However, most of the resistance-temperature characteristics of heat-sensitive ceramic NTC are non-linear. In practical engineering applications, it is often necessary to use a series-parallel circuit to linearize it so that it can give full play to the NTC effect; in addition , linear NTC thermistor in engineering applications, its TCR value and resistance must also be considered factors, generally TCR value and resistance will appear with the increase in use time increases phenomenon, long-term will cause thermistor The comprehensive performance parameters of the device seriously deviate from the design value, which greatly limits the application of NTC thermosensitive materials in high-end fields such as precision control and temperature measurement

[0004] At present, relevant researchers have made great achievements in the research of thermosensitive ceramic materials, including the research of linear NTC thermosensitive ceramic materials, but linear NTC thermosensitive ceramics contain Cd element, which is harmful to the environment; Non-linear NTC ceramic materials are added with conductive materials such as ruthenium oxide, and the linear NTC heat-sensitive materials prepared have the problem of poor linearity.

In addition, the research on thermosensitive polymer composite materials is currently mainly focused on PTC thermosensitive materials, and there is no report on linear NTC thermosensitive polymer composite materials.

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