Preparation method of high-Tc low-resistance lead-free PTC material

A thermistor and positive temperature coefficient technology, which can be applied to resistors with positive temperature coefficient and other directions, which can solve problems such as increasing process costs

A thermistor and positive temperature coefficient technology, which can be applied to resistors with positive temperature coefficient and other directions, which can solve problems such as increasing process costs

CN111056836AInactive Publication Date: 2020-04-24江苏钧瓷科技有限公司
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  • Preparation method of high-Tc low-resistance lead-free PTC material
  • Preparation method of high-Tc low-resistance lead-free PTC material
  • Preparation method of high-Tc low-resistance lead-free PTC material

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] By 0.04(Bi 1 / 2 Na 1 / 2 )TiO 3 -yCaTiO 3 -(0.96-y)BaTiO 3 +0.165mol%Nb 2 o 5 +0.167mol% Al 2 o 3 +1.0mol%TiO 2 +0.2mol% Li 2 CO 3 Carry out batching, wherein y=0.02, 0.04, 0.06, 0.08, 0.10, 0.12, 0.14, 0.16, 0.18, 0.20, weigh after calculating the weight according to the molar ratio in the molecular formula, the weighing quality is as follows in Table 1:

[0021] Table 1. Ingredients list one (unit: g)

[0022] Numbering BNT BaTiO 3

CaTiO 3

Nb 2 o 5

al 2 o 3

TiO 2

Li 2 CO 3

B4-C-00 8.4740 223.8645 0 0.4386 0.1703 0.7987 0.1478 B4-C-02 8.4740 219.2007 2.7189 0.4386 0.1703 0.7987 0.1478 B4-C-04 8.4740 214.5368 5.4377 0.4386 0.1703 0.7987 0.1478 B4-C-06 8.4740 209.8730 8.1566 0.4386 0.1703 0.7987 0.1478 B4-C-08 8.4740 205.2091 10.8755 0.4386 0.1703 0.7987 0.1478 B4-C-10 8.4740 200.5453 13.5944 0.4386 0.1703 0.7987 0.1478 B4-C-12 8.4740...

Embodiment 2

[0028] By 0.06(Bi1 / 2 Na 1 / 2 )TiO 3 -yCaTiO 3 -(0.94-y)BaTiO 3 +0.165mol%Nb 2 o 5 +0.167mol%Al 2 o 3 +1.0mol%TiO 2 +0.2mol%Li 2 CO 3 Carry out batching, y=0.02, 0.04, 0.06, 0.08, 0.10, 0.12, 0.14, 0.16, 0.18, 0.20, weigh after calculating the weight according to the molar ratio in the molecular formula, the weighing quality is as follows Table 3:

[0029] Table 3. Ingredients List II (unit: g)

[0030]

[0031]

[0032] Weigh according to the formula in ingredient list 2, pre-synthesize BNT, CaTiO 3 Then add BaTiO in proportion 3 , Nb 2 o 5 、Al 2 o 3 、TiO 2 , Li 2 CO 3 , using agate balls and deionized water as the medium, ball milling for 24 hours, adding 8wt% polyvinyl alcohol (PVA) with a concentration of 10wt% to the dried powder to granulate, and pressing a Φ10×2.0mm disc with a pressure of 10MPa , hold the pressure for 15s, sinter the pressed disc in the air atmosphere, the sintering temperature is 1330°C, and keep it at this temperature for 10min...

Embodiment 3

[0037] By 0.04(Bi 1 / 2 Na 1 / 2 )TiO 3 -0.06CaTiO 3 -0.90BaTiO 3 +aLi 2 CO 3 +0.165 mol% Nb 2 o 5 +0.167mol%Al 2 o 3 +1.0mol%TiO 2 Carry out batching, wherein a=0~0.003, weigh after calculating the weight according to the molar ratio in the molecular formula, the weighing quality is as follows Table 5:

[0038] Table 5. Ingredients list three (unit: g)

[0039] Numbering BNT BaTiO 3

CaTiO 3

Nb 2 o 5

al 2 o 3

TiO 2

Li 2 CO 3

L-00 8.4740 209.8730 8.1566 0.4386 0.1703 0.7987 0 L-01 8.4740 209.8730 8.1566 0.4386 0.1703 0.7987 0.0739 L-02 8.4740 209.8730 8.1566 0.4386 0.1703 0.7987 0.1478 L-03 8.4740 209.8730 8.1566 0.4386 0.1703 0.7987 0.2217

[0040] Weigh according to the formula in ingredient list 3, pre-synthesize BNT, CaTiO 3 Then add BaTiO in proportion 3 , Nb 2 o 5 、Al 2 o 3 、TiO 2 , Li 2 CO 3 , using agate balls and deionized water as the medium, ball mill...

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Abstract

The invention relates to a preparation method of a lead-free positive temperature coefficient thermistor ceramic with high Curie temperature, high lift-drag ratio and low room temperature resistivitysintered in an atmosphere. According to the method, the following formula is adopted: and x(Bi1 / 2Na1 / 2)TiO3-yCaTiO3-(1-x-y) BaTiO3+aLi2CO3+bSb2O3 powder; wherein x ranges from 0.01 mol% to 0.12 mol%,y ranges from 0 mol% to 0.20 mol%, a ranges from 0 mol% to 0.5 mol%, b ranges from 0 mol% to 0.20 mol%, and one or more of Nb2O5, La2O3, Sm2O3 and Nd2O3 compounds are semiconducting agents, and Al2O3and TiO2 are sintering aids. According to the adopted process, a wafer pressed by the materials is sintered for 10-30 minutes at the temperature of 1250-1380 DEG C in the air atmosphere, so that the wafer is fully sintered, and a solid-phase reaction is realized; and the surface of the sintered wafer is ground, and an electrode is loaded to prepare the PTCR ceramic material. The room-temperature resistivity of the ceramic material is as low as 30 ohm.cm, the Curie temperature Tc is as high as 155 DEG C, and the lift-drag ratio is as high as 106 or above.

Description

technical field [0001] The invention relates to a high Curie temperature (Tc>150°C), high lift-to-drag ratio (R max / R min >1.0×10 6 ), low room temperature resistivity (ρ: ~ 30Ω·cm) lead-free positive temperature coefficient thermistor ceramic preparation method. Background technique [0002] Ferroelectric BaTiO 3 Curie temperature T C It is 120°C, and it can be semiconducted by adding an appropriate amount of donor impurities while having a positive temperature coefficient thermistor effect (PTC effect). PTC materials are widely used in automobiles, home appliances, communications, automation control and other fields. Currently widely used PTC heating elements are made of BaTiO 3 -PbTiO 3 System, T C The higher the number, the more lead content in the material. The most widely used PTC element for air-conditioning heating has a Curie temperature of about 250°C, and the content of PbO in the element exceeds 30wt%. It is well known that Pb, a heavy metal elem...

Claims

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Application Information

Patent Timeline
24 Apr 2020
Publication
CN111056836A
IPC
C04B35/468; C04B35/622; H01C7/02
CPC
C04B35/468; C04B35/622; H01C7/02; C04B2235/3236; C04B2235/3234; C04B2235/3251; C04B2235/3217; C04B2235/3232
Inventors
朱兴文