阅读说明：本技术 一种具有耐高压性能的新型环保ptc热敏电阻 (Novel environment-friendly PTC thermistor with high-voltage resistance ) 是由 漆光智 金德才 吴家慧 王峰 于 2020-12-31 设计创作，主要内容包括：本发明提出一种新型环保PTC热敏电阻瓷体,所述PTC热敏电阻瓷体的配方组成按照质量百分比包括：BaCO-3：55～70％,SrCO-3：3～15％,TiO-2：27～40％,CaCO-3：0.5～2％,Tc-2O-5：0.05～0.20％,Pm-2O-3：0.001～0.003％,MnO-2：0.1～0.4％,LiCO-3：0.06～0.30％,SiO-2:0.06～0.3％,BN:0.1～0.3％。本发明通过Tc-2O-5和Pm-2O-3双施主掺杂,在最大程度上提高减小晶粒的尺寸的效果,达到提高PTC陶瓷的耐电压性能的目的。(The invention provides a novel environment-friendly PTC thermistor ceramic body, which comprises the following components in percentage by mass: BaCO 3 ：55～70％，SrCO 3 ：3～15％，TiO 2 ：27～40％，CaCO 3 ：0.5～2％，Tc 2 O 5 ：0.05～0.20％，Pm 2 O 3 ：0.001～0.003％，MnO 2 ：0.1～0.4％，LiCO 3 ：0.06～0.30％，SiO 2 0.06-0.3% and 0.1-0.3% BN. The present invention passes Tc 2 O 5 Pm and 2 O 3 the double-donor doping improves the effect of reducing the size of crystal grains to the maximum extent, and achieves the purpose of improving the voltage resistance of the PTC ceramic.)

1. The novel environment-friendly PTC thermistor ceramic body is characterized by comprising the following components in percentage by mass: BaCO₃：55～70％，SrCO₃：3～15％，TiO₂：27～40％，CaCO₃：0.5～2％，Tc₂O₅：0.05～0.20％，Pm₂O₃：0.001～0.003％，MnO₂：0.1～0.4％，LiCO₃：0.06～0.30％，SiO₂:0.06～0.3％，BN:0.1～0.3％。

2. A novel environmentally friendly PTC thermistor porcelain according to claim 1, wherein said Tc is₂O₅The mass percentage of the components is as follows: 0.1 to 0.15 percent.

3. A novel environment-friendly PTC thermistor porcelain body according to claim 1, wherein the mass percentage of BN is 0.1-0.2%.

4. The novel environment-friendly PTC thermistor ceramic body according to claim 1, wherein the PTC thermistor ceramic body has a withstand voltage of more than 800V.

5. A novel environment-friendly PTC thermistor porcelain according to claim 1, wherein the PTC thermistor porcelain has an average particle diameter of 10 μm or less.

6. A novel environment-friendly PTC thermistor, characterized by comprising the novel environment-friendly PTC thermistor porcelain body according to any one of claims 1 to 5.

7. A preparation method of a novel environment-friendly PTC thermistor ceramic body is characterized by comprising the following steps:

weighing the main component and the donor doping component according to the mass percentage: BaCO₃：55～70％，SrCO₃：3～15％，TiO₂：27～40％，CaCO₃：0.5～2％，Tc₂O₅：0.05～0.20％，Pm₂O₃: 0.001 to 0.003%; mixing the main component and the donor doping component into a first mixture, and sintering the first mixture into a main material after ball milling;

weighing acceptor doping components and glass phase components according to the mass percentage: MnO₂：0.1～0.4％，LiCO₃：0.06～0.30％，SiO₂:0.06～0.3％，BN:0.1～0.3％；

Adding the acceptor doping component and the glass phase component into the main material to mix into a second mixture, and performing ball milling and granulation;

forming the granulated second mixture into a PTC thermistor blank;

and sintering the PTC thermistor blank to form the PTC thermistor ceramic body.

8. The method for preparing a novel environment-friendly PTC thermistor porcelain according to claim 7, characterized in that: the sintering temperature of the first mixture is 1000-1200 ℃.

9. The method for preparing a novel environment-friendly PTC thermistor porcelain according to claim 7, characterized in that: the sintering temperature of the second mixture is 1200-1400 ℃.

10. The method for preparing a novel environment-friendly PTC thermistor porcelain according to claim 7, characterized in that: the ball milling time is 22-30 hours.

Technical Field

The invention relates to the technical field of inorganic non-metallic materials, in particular to a novel environment-friendly PTC thermistor with high voltage resistance.

Background

The PTC thermistor is a semiconductive electronic ceramic material with positive temperature Coefficient (Positive temperature Coefficient), and the intelligent electronic ceramic element with the characteristics integrates heating and temperature control, and has the characteristics of automatic temperature control, safety, energy conservation, automatic recovery, non-contact action, no open fire, long service life and the like; the product can be used for heating components, temperature control, overcurrent protection, overheat protection, thermal induction and other systems, and is widely applied to the fields of automobiles, electronics, communication, power transmission and transformation engineering, air conditioner and fan heater engineering, low-energy-consumption safety household appliances, demagnetization, overcurrent protection, overheat protection and the like.

At present, the most commonly used PTC thermistors are BaTiO 3-based ceramic materials, in order to improve the working performance of the thermistors, lead oxide or lead-containing compounds are added for mixing, lead is a heavy metal element with toxicity, and in the production process of the PTC thermistors, the lead can pollute the natural environment and cause harm to the health of human beings, the use of lead-containing products is strictly controlled in various countries in the world, and lead-free environment-friendly PTC thermistors are inevitably substituted for lead-containing products. Meanwhile, donor impurities of the conventional PTC thermistor are generally Nb2O5 or Y2O3 for forming the semi-conduction of the PTC ceramic, and TiO2, SiO2 and BN for adsorbing harmful impurities inside are generally adopted as glass phases, so that the semi-conduction degree of crystal grains is improved, and the growth of the crystal grains can be controlled. The PTC thermistor added conventionally has weak capability for controlling the growth of crystal grains in the PTC thermistor, causes uneven and large sizes of the crystal grains after sintering, when high voltage is applied to two ends of the PTC electrode, because of uneven sizes of the crystal grains, the voltage born by each crystal grain has larger difference, the voltage born by the large crystal grains is much larger than that born by the small crystal grains, so that the large crystal grains can not bear easily to cause breakdown, and the voltage effect of the PTC is increased due to the larger crystal grain size and the unevenness, and the breakdown voltage is reduced from the other side, and the voltage resistance is poor.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a novel environment-friendly PTC thermistor with high voltage resistance.

The technical scheme for realizing the purpose of the invention is as follows:

the novel environment-friendly PTC thermistor ceramic body comprises the following components in percentage by mass: BaCO₃：55～70％，SrCO₃：3～15％，TiO₂：27～40％，CaCO₃：0.5～2％，Tc₂O₅：0.05～0.20％，Pm₂O₃：0.001～0.003％，MnO₂：0.1～0.4％，LiCO₃：0.06～0.30％，SiO₂:0.06～0.3％，BN:0.1～0.3％。

Alternatively, the Tc₂O₅The mass percentage of the components is as follows: 0.1 to 0.15 percent.

Optionally, the BN accounts for 0.1-0.2% by mass

Optionally, the PTC heat-sensitive electronic porcelain body has a withstand voltage of more than 800V.

Optionally, the PTC heat-sensitive electronic porcelain has an average particle diameter of 10 μm or less.

The invention discloses a novel environment-friendly PTC thermistor which comprises a novel environment-friendly PTC thermistor ceramic body.

A preparation method of a novel environment-friendly PTC thermistor ceramic body comprises the following steps:

weighing the main component and the donor doping component according to the mass percentage: BaCO₃：55～70％，SrCO₃：3～15％，TiO₂：27～40％，CaCO₃：0.5～2％，Tc₂O₅：0.05～0.20％，Pm₂O₃：0.001～0.003%; mixing the main component and the donor doping component into a first mixture, and sintering the first mixture into a main material after ball milling;

weighing acceptor doping components and glass phase components according to the mass percentage: MnO₂：0.1～0.4％，LiCO₃：0.06～0.30％，SiO₂:0.06～0.3％，BN:0.1～0.3％；

Adding the acceptor doping component and the glass phase component into the main material to mix into a second mixture, and performing ball milling and granulation;

forming the granulated second mixture into a PTC thermistor blank;

and sintering the PTC thermistor blank to form the PTC thermistor ceramic body.

Optionally, the sintering temperature of the first mixture is 1000-1200 ℃.

Optionally, the sintering temperature of the second mixture is 1200-1400 ℃.

Optionally, the ball milling time is 22 to 30 hours.

The invention has the positive effects that:

the doping component of the invention adopts Tc₂O₅Pm and₂O₃in complex addition, Tc⁵⁺Ionic radius of (2) and Ti⁴⁺Ionic proximity, possible substitution of Ti⁴⁺Bit serves as donor, and Pm³⁺Ionic radius of and Ba²⁺Similarly, Ba may be substituted²⁺Bit serving as donor impurity, Tc^{5 +}And Pm³⁺The effect of inhibiting the grain growth is obvious and is superior to the traditional doping ions, such as: nb⁵⁺、Y³⁺、Sb⁵⁺And the effect of reducing the size of crystal grains can be improved to the maximum extent by adopting composite doping, so that the aim of improving the voltage resistance of the PTC ceramic is fulfilled.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the embodiments of the present invention will be described in detail below. However, it will be appreciated by those of ordinary skill in the art that numerous technical details are set forth in order to provide a better understanding of the present application in various embodiments of the present invention. However, the technical solution claimed in the present application can be implemented without these technical details and various changes and modifications based on the following embodiments. The following embodiments are divided for convenience of description, and should not constitute any limitation to the specific implementation manner of the present invention, and the embodiments may be mutually incorporated and referred to without contradiction.

Example 1

The embodiment of the novel environment-friendly PTC thermistor with high voltage resistance and the preparation method thereof,

step one, weighing the main component and the donor doping component according to the following mass percentages: BaCO₃：55％，SrCO₃：7.5％，TiO₂：35％，CaCO₃：1.5％，Tc₂O₅：0.1％，Pm₂O₃: 0.003 percent of the total weight of the components, mixing the components into a first mixture, discharging the mixture after ball milling for 22 hours, press filtering the mixture, and sintering the mixture at 1100 ℃ to be used as a main material.

This example used Tc as the donor doping component₂O₅Pm and₂O₃in complex addition, Tc⁵⁺Ionic radius of (2) and Ti⁴⁺Ionic proximity, possible substitution of Ti⁴⁺Bit serves as donor, and Pm³⁺Ionic radius of and Ba²⁺Similarly, Ba may be substituted²⁺Bit serving as donor impurity, Tc⁵⁺And Pm³⁺The effect of inhibiting the grain growth is obvious and is superior to the traditional doping ions, such as: nb⁵⁺、Y³⁺、Sb⁵⁺And the effect of reducing the size of crystal grains can be improved to the maximum extent by adopting composite doping, so that the aim of improving the voltage resistance of the PTC ceramic is fulfilled.

Step two: adding an acceptor and a glass phase component according to the following mass percentage, wherein the acceptor is MnO₂: 0.3%, glass phase: li₂CO₃：0.2％、SiO₂: 0.2%, BN: 0.2 percent of the mixture is fully mixed, added into the main material of the first mixture in the step one to be mixed into a second mixture, and granulated after ball milling for 22 hours, wherein the granulation can be selected from the common granulation methods in the fieldThe method, such as spray granulation or artificial granulation, the granulated powder is subjected to dry pressing and molding, and is sintered into the PTC thermistor ceramic body at 1250 ℃;

step three: and (3) carrying out post-processing on the PTC thermistor ceramic body prepared in the step (II), such as: and finally obtaining a finished product by electrode, soldering tin, coating and sealing and testing, wherein the size of the product is phi 8mm multiplied by 2 mm.

Example 2

The embodiment provides a novel environment-friendly PTC thermistor with high voltage resistance and a preparation method thereof,

step one, the mass percentages of main components and donor doping components are as follows: BaCO₃：68％，SrCO₃：3.5％，TiO₂：27.5％，CaCO₃：0.5％，Tc₂O₅：0.1％，Pm₂O₃: 0.002 percent of the first mixture is mixed into a first mixture, the first mixture is discharged and filter-pressed after ball milling for 25 hours, and the first mixture is sintered as a main material at 1150 ℃.

Step two: in this embodiment, the main component and the donor doping component further include the following acceptor doping component and glass phase component by mass percent: MnO₂：0.1％，Li₂CO₃：0.1％，SiO₂: 0.1%, BN:0.1 percent of the mixture is fully mixed, added into the main material of the first mixture in the step one to be mixed into a second mixture, granulated after ball milling for 25 hours, and sintered into a PTC thermistor ceramic body at 1300 ℃;

step three: and (3) carrying out post-processing on the PTC thermistor ceramic body prepared in the step (II), such as: and finally obtaining a finished product by electrode, soldering tin, coating and sealing and testing, wherein the size of the product is phi 8mm multiplied by 2 mm.

Example 3

This example provides a novel environment-friendly PTC ceramic with high pressure resistance and a method for preparing the same,

step one, the mass percentages of main components and donor doping components are as follows: BaCO₃：56％，SrCO₃：14％，TiO₂：29％，CaCO₃：0.5％，Tc₂O：0.15％，Pm₂O: 0.001% by weight, mixed to form a mixture AAnd discharging, press-filtering and sintering at 1180 deg.C as main material after ball milling for 30 hr.

Step two: in this embodiment, the main component and the donor doping component further include the following acceptor doping component and glass phase component in percentage by weight: MnO₂：0.1％，Li2CO₃：0.07％，SiO₂: 0.08%, BN:0.1 percent of the mixture is fully mixed, added into the main material A in the step one to be mixed into a mixture B, is granulated after ball milling for 30 hours, and is subjected to dry pressing forming to be sintered into PTC ceramic at 1320 ℃;

step three: and (3) further processing the PTC ceramic chip prepared in the step (II), such as: and finally obtaining a finished product by electrode, soldering tin, coating and sealing and testing, wherein the size of the product is phi 8mm multiplied by 2 mm.

Comparative example 1

The present comparative example is a conventional PTC thermistor and a method for preparing the same,

step one, the mass percentages of main components and donor doping components are as follows: BaCO₃：56％，SrCO₃：14％，TiO₂：29％，CaCO₃：0.5％，Y₂O₃: 0.15 percent of the mixture A is mixed into a mixture A, the mixture A is discharged after ball milling for 30 hours, and is filter-pressed and sintered at 1180 ℃ to be used as a main material.

Step two: the main component and the donor doping component of the comparative example are also added with the following acceptor doping component and glass phase component by weight percentage: MnO₂：0.1％，Li₂CO₃：0.07％，SiO₂: 0.08%, BN:0.1 percent of the mixture is fully mixed, added into the main material A in the step one to be mixed into a mixture B, is granulated after ball milling for 30 hours, and is subjected to dry pressing forming to be sintered into PTC ceramic at 1320 ℃;

step three: and (3) further processing the PTC ceramic chip prepared in the step (II), such as: and finally obtaining a finished product by electrode, soldering tin, coating and sealing and testing, wherein the size of the product is phi 8mm multiplied by 2 mm.

The PTC thermistor porcelain pieces were photographed by Scanning Electron Microscopy (SEM) to obtain average particle diameters.

The breakdown voltage values were measured for the product samples prepared in examples and comparative examples using a pressing speed of 50V/min. The average particle diameter and the destruction electron value are shown in Table 1.

TABLE 1

Example number	Average grain size (. mu.m)	Resistivity at room temperature (Ω cm)	Breakdown voltage value (V)
				Example 1	5	350	950
Example 2	7	250	850
				Example 3	6	300	900
Comparative example 1	12	200	500

As can be seen from the test results, the PTC ceramic formulation provided by the invention has the advantages of finer grain size, higher room temperature resistivity and higher pressure resistance value. The PTC resistor of the invention has a withstand voltage value of 800V or more.

The foregoing is merely a preferred embodiment of the invention and is not intended to limit the invention in any manner; those skilled in the art can make numerous possible variations and modifications to the present teachings, or modify equivalent embodiments to equivalent variations, without departing from the scope of the present teachings, using the methods and techniques disclosed above. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present invention are still within the scope of the protection of the technical solution of the present invention.