A kind of positive temperature coefficient thermistor material and preparation method thereof

A positive temperature coefficient and thermistor technology, which is applied in the manufacture of resistors with positive temperature coefficients, thermistors, and resistors. And other issues

Active Publication Date: 2015-12-02
BYD CO LTD
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The Curie temperature of the existing barium titanate-based positive temperature coefficient thermistor material is 120°C. In order to increase the working temperature of the thermistor, the barium titanate powder can be semiconducted by doping, etc., and the existing published With Pb, Sr, Ca, Y, Nb, Bi, Ce, La and other donor doping and Mn, Fe, Mg and other acceptor doping, a semiconducting thermistor can be obtained to improve the high withstand voltage characteristics of PTC and Improve its Curie point, but the above-mentioned doping causes the room temperature resistance of the thermistor to increase. At the same time, when the donor or acceptor is single-doped for semiconducting, the sintering process is not easy to control, and the barium titanate cannot be uniformly Semiconducting leads to uneven particle size of barium titanate powder in the sintering process, large grain and grain boundary resistance, which also leads to high room temperature resistance and low lift-to-drag ratio of the product, which restricts its development and application

Method used

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  • A kind of positive temperature coefficient thermistor material and preparation method thereof
  • A kind of positive temperature coefficient thermistor material and preparation method thereof
  • A kind of positive temperature coefficient thermistor material and preparation method thereof

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preparation example Construction

[0022] The present invention simultaneously provides a preparation method for the above-mentioned positive temperature coefficient thermistor material, the steps comprising:

[0023] S1, by mass ratio BaTiO 3 :B 2 o 3 :SiO2 2 : Li 2 O:P 2 o 5 :Cs 2 O:Nd 2 o 3 =94.85%~97.75%: 0.4%~2.5%: 0.5%~0.9%: 0.08%~0.2%: 0.2%~0.3%: 0.6%~0.725%: 0.325%~0.565% mix barium titanate and oxide , ball milling, wherein, the mixing order and manner of each material are not limited in the present invention, and various ball milling techniques known to those skilled in the art can be used in the ball milling present invention, for example, a planetary ball mill can be used.

[0024]S2, including performing the first sintering on the powder material obtained in step S1 at 800-900°C, preferably the first sintering time is 100-120min, and the heating rate to the first sintering temperature is 4.2-5.2°C / min,

[0025] Preferably, the first sintering can adopt non-one-stage sintering, that is, pr...

Embodiment 1

[0041] 1. BaTiO 3 Powder preparation:

[0042] (a) Prepare analytically pure barium chloride and oxalic acid into 0.5mol / L and 1.0mol / L solutions with deionized water respectively, mix well and let stand.

[0043] (b) Take 1000ml of oxalic acid solution and place it in an electronic constant temperature water bath at 60°C, then add barium chloride solution and analytically pure butyl titanate into the oxalic acid solution at 50ml / min, and turn on the magnetic stirrer for stirring, wherein the raw materials The ratio is barium chloride: butyl titanate: oxalic acid = 1:1:2, and the pH value of the solution is always controlled between 2.5 and 3.5 with ammonia water.

[0044] (C) Control the co-precipitation reaction time to be about 1 hour. After the reaction is over, turn off the magnetic stirrer and the constant temperature water bath, and leave the precipitate to stand for aging to obtain the titanium barium oxalate precursor. Then wash and filter to remove chloride ions an...

Embodiment 2

[0059] The PTC material sample S2 was prepared by the same method as in Example 1, except that (i) sintering in step 2: put the molded pellets obtained above into a high-temperature sintering furnace for sintering, and the heating rate was 5°C / min. Heat at 600°C for 100 minutes, remove the organic binder, hold at 1150°C for 40 minutes, perform supplementary synthesis, raise the temperature to 1225°C at 8°C / min, hold for 70 minutes, cool down at a rate of 2.3°C / h, cool down to 1100°C, and hold for 50 minutes , fully oxidized, cooled down to 200°C again, and cooled naturally to room temperature.

[0060] Using FESEM / EDS-field emission scanning electron microscope and accessory energy spectrometer to carry out scanning electron microscope analysis on the prepared PTC material sample S2, the electron microscope picture is as follows figure 2 .

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Abstract

A thermistor material and a method for preparing a thermistor material are provided. The thermistor material is prepared by mixing and heating a mixture containing BaTiO3, B2O3, SiO2, Li2O, P2O5, Cs2O, Nd2O3, Al2O3 and TiO2.

Description

technical field [0001] The invention relates to a positive temperature coefficient (PTC) thermistor material and a preparation method thereof. Background technique [0002] Positive temperature coefficient (PTC) thermistor materials 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 prevent overcurrent or overcurrent The role of temperature protection. In particular, barium titanate-based positive temperature coefficient thermistors have relatively large temperature coefficients, and a series of characteristics produced by them have good applications in many industries. [0003] The Curie temperature of the existing barium titanate-based positive temperature coefficient thermistor material is 120°C. In order to increase the working temperature of the thermistor, the barium titanate powder can be semiconduct...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C04B35/468C04B35/622
CPCC04B35/4682C01G23/006C04B35/6261C04B35/62685C04B35/62695C04B35/63416C04B2235/32C04B2235/3201C04B2235/3203C04B2235/3217C04B2235/3224C04B2235/3232C04B2235/3236C04B2235/3409C04B2235/3418C04B2235/449C04B2235/5427C04B2235/6562C04B2235/6565C04B2235/6567C04B2235/785H01C7/02H01C7/023C04B35/462C04B35/64C04B35/653C04B2235/34H01C7/008H01C7/025H01C17/06533
Inventor 赵严帅周维
Owner BYD CO LTD
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