Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Heat treatment method for improving strength of PTC (Positive Temperature Coefficient) thermistor core materials

A heat treatment method and the technology of thermistors, which are applied in the direction of resistors with positive temperature coefficients, etc., can solve the problems of large amount of conductive fillers, high-temperature resistance that cannot meet the requirements, and carbon black conductive particles are prone to agglomeration, etc., to achieve annealing Method optimization, improvement of PTC strength, effect of annealing temperature optimization

Inactive Publication Date: 2012-07-04
SHANGHAI CHANGYUAN WAYON CIRCUIT PROTECTION CO LTD
View PDF0 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Limited by the performance of raw materials such as crystalline polymers and carbon-based conductive fillers, in order to achieve low resistivity, a large amount of conductive fillers is added, which makes carbon black conductive particles easy to agglomerate, resulting in carbon black conductive particles at high temperatures. The formed conductive chain cannot be broken, and the high temperature resistance cannot meet the requirements

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Heat treatment method for improving strength of PTC (Positive Temperature Coefficient) thermistor core materials

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] High-density polyethylene 50 parts

[0029] 50 parts of carbon black.

[0030] Among them, the high-density polyethylene has a crystallinity of not less than 70% and a density of not less than 0.94g / cm 3 ; The carbon black is furnace carbon black, the particle size is 20-100nm, and the DBP oil absorption value is not less than 70ml / 100g.

[0031] The preparation method is as follows: mix high-density polyethylene and carbon black in a high-speed mixer for 20 minutes, extrude the mixed formula in a twin-screw extruder, and break it to obtain high-density polyethylene and carbon black. Black composite material. Then extrude a sheet with required thickness in the integrated extruder, and compound a layer of electrode sheets on both sides of the sheet. The sheet was irradiated, annealed at 130°C for 5h, and slowly cooled to 50°C at a rate of 2°C / min. The cooled chip is punched into small pieces by a punch to make a PTC thermistor element.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
densityaaaaaaaaaa
particle diameteraaaaaaaaaa
oil absorption valueaaaaaaaaaa
Login to View More

Abstract

The invention relates to a heat treatment method for improving the strength of PTC (Positive Temperature Coefficient) thermistor core materials. The thermistor core materials comprise the following components in percentage by weight: 45-50 parts of high-density polyolefin and 50-55 parts of carbon black, wherein the polyolefin is the high-density polyolefin with high crystallinity of greater than or equal to 70 percent and the density of greater than or equal to 0.94g / cm<3>; and the carbon black is the stove method carbon black with good electrical conductivity, the grain size of 20-100nm and the DBP oil absorption value of greater than or equal to 70ml / 100g. The heat treatment method for composite materials comprises the step of annealing under the condition above a melting point of polymer at a temperature of 10-30 DEG C for 4-6 hours. Under the condition that the performances of the raw materials are unchanged, through optimization of an annealing temperature and the annealing manner, the PTC strength of the composite materials is greatly improved, and a foundation is laid for development of PTC thermistor components with high withstand voltage level.

Description

technical field [0001] The invention relates to a heat treatment method for improving the strength of a core material of a PTC thermistor, and relates to a heat treatment method for improving the strength of a core material for a PTC overcurrent and overtemperature protection element composed of crystalline high polymer and carbon black filler as main raw materials. Background technique [0002] Under normal conditions, the protection element connected in series with the load in the circuit is in a state of low temperature and low resistance. When an overcurrent or overheating condition occurs, the resistance of the protection element rises sharply to achieve the purpose of cutting off the power supply. On the one hand, this protection element requires that the resistance at room temperature is low enough to reduce the impact on the circuit to be protected. On the other hand, at high temperature, the resistance is required to be high enough to withstand higher voltage level...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): H01C7/02
Inventor 王炜刘正平刘玉堂
Owner SHANGHAI CHANGYUAN WAYON CIRCUIT PROTECTION CO LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com