CN100567207C - A kind of low-resistivity/high B-value negative temperature coefficient thermo-sensitive material and preparation method thereof - Google Patents
A kind of low-resistivity/high B-value negative temperature coefficient thermo-sensitive material and preparation method thereof Download PDFInfo
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- CN100567207C CN100567207C CNB2007101137711A CN200710113771A CN100567207C CN 100567207 C CN100567207 C CN 100567207C CN B2007101137711 A CNB2007101137711 A CN B2007101137711A CN 200710113771 A CN200710113771 A CN 200710113771A CN 100567207 C CN100567207 C CN 100567207C
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- 239000000463 material Substances 0.000 title claims abstract description 64
- 238000002360 preparation method Methods 0.000 title claims description 9
- 239000000654 additive Substances 0.000 claims abstract description 29
- 230000000996 additive effect Effects 0.000 claims abstract description 29
- 238000000034 method Methods 0.000 claims abstract description 10
- 229910004353 Ti-Cu Inorganic materials 0.000 claims abstract description 9
- 239000000919 ceramic Substances 0.000 claims abstract description 9
- 150000001875 compounds Chemical class 0.000 claims abstract description 7
- 229910052596 spinel Inorganic materials 0.000 claims abstract description 7
- 239000011029 spinel Substances 0.000 claims abstract description 7
- 238000005245 sintering Methods 0.000 claims description 17
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 16
- NUJOXMJBOLGQSY-UHFFFAOYSA-N manganese dioxide Chemical compound O=[Mn]=O NUJOXMJBOLGQSY-UHFFFAOYSA-N 0.000 claims description 16
- ZKATWMILCYLAPD-UHFFFAOYSA-N niobium pentoxide Chemical compound O=[Nb](=O)O[Nb](=O)=O ZKATWMILCYLAPD-UHFFFAOYSA-N 0.000 claims description 7
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 claims description 6
- 238000000498 ball milling Methods 0.000 claims description 5
- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 4
- 239000000203 mixture Substances 0.000 claims description 4
- 229920002451 polyvinyl alcohol Polymers 0.000 claims description 4
- 238000009472 formulation Methods 0.000 claims description 3
- 229910010413 TiO 2 Inorganic materials 0.000 claims description 2
- 239000000853 adhesive Substances 0.000 claims description 2
- 230000001070 adhesive effect Effects 0.000 claims description 2
- 239000003795 chemical substances by application Substances 0.000 claims description 2
- 238000000227 grinding Methods 0.000 claims description 2
- 239000002245 particle Substances 0.000 claims description 2
- 238000005516 engineering process Methods 0.000 description 5
- 229910018054 Ni-Cu Inorganic materials 0.000 description 4
- 229910018481 Ni—Cu Inorganic materials 0.000 description 4
- 229910052802 copper Inorganic materials 0.000 description 4
- 229910020637 Co-Cu Inorganic materials 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 230000005611 electricity Effects 0.000 description 3
- 238000005469 granulation Methods 0.000 description 3
- 230000003179 granulation Effects 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 2
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 238000007493 shaping process Methods 0.000 description 2
- 229910052709 silver Inorganic materials 0.000 description 2
- 239000004332 silver Substances 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 230000003139 buffering effect Effects 0.000 description 1
- 229910001424 calcium ion Inorganic materials 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000013256 coordination polymer Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 229910052573 porcelain Inorganic materials 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000009827 uniform distribution Methods 0.000 description 1
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Abstract
The invention discloses a kind of required thermo-sensitive material of temperature-sensing element of sensor technical field, disclose a kind of low-resistivity/high B-value negative temperature coefficient thermo-sensitive material especially.This low-resistivity/high B-value negative temperature coefficient thermo-sensitive material, its special character is: by the oxide compound of Mn-Ti-Cu, and add the additive that Zn-Ca-Nb forms, make the thermo-sensitive material with spinel structure through ceramic process; The density of material is 4.9-5.1g/cm
3, the resistivity of material in the time of 25 ℃ is 20-100 Ω cm, the B value of 25 ℃ of-50 ℃ of warm areas is 2600-3300K.The present invention has low-resistivity/high B value characteristics, is the required important materials of power type thermal resistance.The cost of material only is 1/3rd or 1/4th of the conventional material that uses, and has consistence preferably, and is repeated and stable, and it is particularly suitable for the NTCR element that surge current absorbs.
Description
(1) technical field
The present invention relates to the required thermo-sensitive material of temperature-sensing element of sensor technical field, particularly a kind of low-resistivity/high B-value negative temperature coefficient thermo-sensitive material and preparation method thereof.
(2) background technology
Power-type NTCR is widely used for the temperature compensation in each field and the protection of circuit and appliance component.Because power is big, component size is big, and materials are many, and the low cost of material becomes the target that producers pursue.Original adoption Mn-Co-Cu based material, (about 430 yuan of CO3O4 unit price/kg), people have used the Mn-Ni-Cu based material instead and have substituted Mn-Co-Cu because the price increase of Co.At present the price of Ni than early stage price exceed 4-5 doubly (present price of NiO be 280 yuan/kg), force people to have to seek not contain the prescription of Ni.Do not see the prescription that power-type NTCR requires that satisfies that does not contain Ni up to now as yet.
Power-type NTCR, especially surge current absorption of N TCR require to have high as far as possible B value and lower resistivity.Resistivity at room temperature is generally 10-100 Ω cm, and the B value is the 2500-3200K scope.Adopt Mn-Co-Cu very easily to satisfy this requirement; Employing contains the above Mn-Ni-Cu of Ni15% also can reach this purpose.And any other prescription that does not contain Co and Ni all is difficult to reach this requirement.
(3) summary of the invention
The present invention provides a kind of cheap low-resistivity/high B-value negative temperature coefficient thermo-sensitive material and preparation method thereof in order to remedy the deficiencies in the prior art.
The present invention is achieved through the following technical solutions:
A kind of low-resistivity/high B-value negative temperature coefficient thermo-sensitive material, its special character is: by the oxide compound of Mn-Ti-Cu, and add the additive that Zn-Ca-Nb forms, make the thermo-sensitive material with spinel structure through ceramic process; The density of material is 4.7-5.0g/cm
3, the resistivity of material in the time of 25 ℃ is 20-100 Ω cm, the B value of 25 ℃ of-50 ℃ of warm areas is 2600-3300K.
Low-resistivity/high B-value negative temperature coefficient thermo-sensitive material of the present invention, Mn-Ti-Cu oxide compound are MnO2, TiO2 and CuO, and its weight ratio is: MnO
2: TiO
2: CuO=(65-75): (5-15): (10-20).The Zn-Ca-Nb additive is ZnO, CaO and Nb2O5, and the weight percent that joins in the main formula is 8-10%.Additive is pressed ZnO: CaO: Nb
2O
5=30: 60: 10 formulation by weight, synthetic at 850 ℃/2.5-3 hour after grinding 12 hours.
The preparation method of low-resistivity/high B-value negative temperature coefficient thermo-sensitive material of the present invention by the oxide compound of Mn-Ti-Cu, and adds the additive that Zn-Ca-Nb forms, and makes the thermo-sensitive material with spinel structure through ceramic process; Ceramic process prepares material in the additional proportion of main formula ratio and additive and carries out 8-12 hour ball milling, the oven dry back adds suitable adhesive and causes 80-200 purpose particle, and make the disk of various diameters and thickness, under 1200-1240 ℃ of high temperature sintering 2.5-3 hour.
The preparation method of low-resistivity/high B-value negative temperature coefficient thermo-sensitive material of the present invention, tackiness agent is a polyvinyl alcohol, add-on is the 2-3% of material total amount.The sintering curre of high temperature sintering is a level and smooth para-curve, and promptly 25 ℃-1220 ℃ heated up 13 hours, 1220 ℃ constant temperature 2.5-3.0 hour, lower the temperature with stove then.
Principle of the present invention and concrete technical scheme:
1, low-cost low-resistivity/high B value material prescription
Oxide heat sensitive material is (AB2O4) for the spinel structure general formula, and electricity is led the exchange that mainly results from B-B position 3d orbital electron.For the Mn-Ti-Cu material, Ti and Cu ion are in the B position, promptly form electricity and lead by the exchange of Ti and Cu ion 3d track, the resistivity of material depend primarily on Ti and Cu ionic what.Simultaneously less by the radius of Ti, when being combined into crystal, lattice produces deformation, makes the variable in distance between B-B and the A-B, and the intensity of activation of lattice reduces, and promptly the B value diminishes.Compare with the prescription that contains Co and Ni, Mn-Ti-Cu has lower resistivity and higher B value.Experiment shows, as its MnO2: TiO: CuO=(65-75): (5-15): in the time of (10-20), resistivity is 20-100 Ω cm, the B value is 2600K-3300K, the amount of Ti increases, and resistivity can increase, because the 3D electronics of Ti only has two, want much less compared with Co and Ni, so the big more resistance of the amount of Ti is high more.Cu increases resistance decreasing, and the 3D electronics of Cu has 16, so Cu increases resistance decreasing, Ti and Cu compensate mutually, and the surge NTCR that is content with very little requires resistivity (10-100 Ω cm) and B value (2400-3000K).
2, additive
The present invention adopts the additive that synthesizes of Zn-Ca-Nb2O5.Zn in the additive and Ca ion enter the B position of spinel structure, and branch replaces the TiO ion of B position, provide electricity to lead with its 4S electronics, with the resistivity of reduction material; Zn can substitute the part Ti ion and the Cu ion of B position, and the deformation of buffering lattice stops the decline of B value.Additive to give synthetic be for it has more uniform distribution in material, to improve the homogeneity of material.The add-on X (%) that experiment shows (Fig. 1) additive 10% with interior to the influence of B value not quite, but clearly to the influence of resistivity; When X greater than 10%, the B value descends rapidly.X value limit is at 5-10% in the present invention.
3. low resistance/high B value thermistor composition of the present invention adopts the ceramic process preparation, and its technical process is as follows:
1. batching: press MnO2: TiO2: the % of CuO additive=(65-75): (5-15) %: (10-20) %: (5-10) % additive
2. ball milling: material: water: ball (ZrO2 ball)=1.0: (1.1-1.4): (1.5-2.0) %wt
3. granulation: PVA=(2-2.5) %wt, granularity: 80-200 order
4. be shaped: d=Φ 5-Φ 26, thickness (1-2.0) mm, shaping density: 3.2-3.6g/cm
3
5. sintering: 1.6 ℃/min of 25 ° of-1220 ℃/heat-up rates, 1200-1240 ℃ of insulation 2.5-3 hour lowered the temperature with stove.
6. roasting is silver-colored: (according to silver slurry reduction temperature), the most handy 750 ℃ of reduction slurries, 15-25min.Prescription in this technology and be sintered to critical process.Prescription has determined that material behavior, sintering then are to realize the assurance of this characteristic.The relation of sintering temperature and resistivity of material and B value such as Fig. 2.Sintering temperature is lower than optimal sintering temperature (1220 ℃), and resistivity of material is very big, is higher than 1300 ℃, and resistivity of material descends rapidly, and the B value also descends significantly, does not become porcelain and burning to make the homogeneity extreme difference of material.
The present invention, adds the additive that contains Zn-Ca-Nb resistivity and B value is compensated for Ni with Ti, can realize the material parameter that power-type NTCR requires.This material has low-resistivity/high B value characteristics, is the required important materials of power type thermal resistance.The cost of material only is 1/3rd or 1/4th of the conventional material that uses, and has consistence preferably, and is repeated and stable, and it is particularly suitable for being used as the NTCR element that surge current absorbs.
(4) description of drawings
Fig. 1 is the synoptic diagram of the add-on X (%) of additive of the present invention to the influence of B value;
Fig. 2 is the synoptic diagram of sintering temperature of the present invention and resistivity of material and B value relation.
(5) embodiment
Embodiment 1:
1. fill a prescription: with MnO2, TiO2 and CuO is raw material, and purity is CP, gets MnO2: TiO2:
CuO=65: 15: 20 (%wt)+8% (additive)
=70: 10: 20 (%wt)+8% (additive)
=72: 8: 20 (%wt)+8% (additive)
=73: 5: 20 (%wt)+8% (additive)
Additive: ZnO: CaO: Nb2O5=30: 60: 10%wt, 8 hours ball millings, 750 ℃ were given burning 3 hours.
2. with aforementioned proportion formulation material ball milling 12 hours, material: water: ball=1.0: 1.1: 1.5
3, granulation: adding concentration is 10% PVA sol solution 23%wt in powder, and the 80-200 mesh sieve is crossed in manual granulation.
4. be shaped: use 20mpa pressure, the base sheet of shaping Φ 10 (mm) * 2.0mm, pressed density is 3.6g/cm
3
5. the base sheet that is shaped is packed in the ceramic alms bowl under 1220 ℃ of high temperature sintering 2.5 hours.Sintering curre be 25 °-1220 ℃ with 13 hours, i.e. the about 1.5 ℃/min of heat-up rate.,, below 200 ℃, come out of the stove after 2.5 hours 1220 ℃ of insulations with the stove cooling.
6. roasting silver electrode, 780 ℃ of reductase 12 0min.
7. the R of sample is measured in test in 25 ℃ ± 0.01 ℃ thermostatic oil bath
25With the value of R50 and calculate ρ 25 and B
25/
50Its result such as following table
(with 100 chip statistics)
The result shows, along with the minimizing of TiO2 amount, resistance descends, and B value also has decline, the homogeneity of resistance value and B value even identical with the Mn-Ni-Cu based material.
Embodiment 2:
Main formula is got MnO2: TiO2: CuO=70: 10: 20%wt, the amount of additive is taken as 5.0,7.0,8.0,9.0,10.0 respectively, 12.0%wt, is made into the sample of Φ 10, its test result such as following table (with 100 chips statistics) by the technology of embodiment 1
The result shows that along with the increase of additive capacity, resistance descends, and the B value also obviously descends.When the consumption of additive reached 12%, resistance was 5 Ω, and the B value only is 2280K, and the dispersion of material becomes big.
Embodiment 3:
Prescription is got MnO2: TiO2: CuO=70: 10: 20%wt, the amount of additive is that 8%wt[is by embodiment 1] technology make Φ 10 base sheets, get different sintering temperature sintering, the measuring result of sample such as following table (with 100 chips statistics)
The result shows that sintering temperature is lower than 1220 ℃, is higher than 1240 ℃, and the sample consistence degenerates, so optimum temps is 1220-1240 ℃, if the amount of prescription CuO increases, the sintering temperature contains decline, and same CuO amount reduces, and sintering temperature contains corresponding increase.
Material prescription of the present invention and technology of preparing can be produced in batches, and the performance of material satisfies the requirement of compensation NTCR and surge NTCR, and the cost of material only is 1/3rd or 1/4th of a conventional used Mn-Ni-Cu based material price.
Claims (3)
1. low-resistivity/high B-value negative temperature coefficient thermo-sensitive material is characterized in that: as main formula, and add the additive that Zn-Ca-Nb forms by the oxide compound of Mn-Ti-Cu, make the thermo-sensitive material with spinel structure through ceramic process; The density of material is 4.7-5.0g/cm
3, the resistivity of material in the time of 25 ℃ is 20-100 Ω cm, the B value of 25 ℃ of-50 ℃ of warm areas is 2600-3300K; The Mn-Ti-Cu oxide compound is MnO2, TiO2 and CuO, and its weight ratio is: MnO
2: TiO
2: CuO=(65-75): (5-15): (10-20); The Zn-Ca-Nb additive is ZnO, CaO and Nb2O5, and the amount that joins in the main formula is the 8-10% of main formula weight; Additive is pressed ZnO: CaO: Nb
2O
5=30: 60: 10 formulation by weight, synthetic at 850 ℃/2.5-3 hour after grinding 12 hours.
2. the preparation method of low-resistivity/high B-value negative temperature coefficient thermo-sensitive material according to claim 1, it is characterized in that: by the oxide compound of Mn-Ti-Cu as main formula, and add the additive that Zn-Ca-Nb forms, make thermo-sensitive material with spinel structure through ceramic process; Ceramic process prepares material in the additional proportion of main formula ratio and additive and carries out 8-12 hour ball milling, the oven dry back adds suitable adhesive and causes 80-200 purpose particle, make the disk of various diameters and thickness, under 1200-1240 ℃ of high temperature sintering 2.5-3 hour.
3. the preparation method of low-resistivity/high B-value negative temperature coefficient thermo-sensitive material according to claim 2, it is characterized in that: tackiness agent is a polyvinyl alcohol, its add-on is the 2-3wt% of material total amount.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104495942A (en) * | 2014-12-31 | 2015-04-08 | 郑州大学 | Negative thermal expansion material NdMnO3 and preparation method thereof |
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| CN101425352B (en) * | 2008-11-11 | 2010-12-01 | 南京时恒电子科技有限公司 | Technical process for enhancing stability of NTC heat variable resistor |
| CN101492289B (en) * | 2009-01-04 | 2011-12-28 | 山东中厦电子科技有限公司 | High-resistivity/low-B value thermistor composition and method of producing the same |
| CN101492284B (en) * | 2009-01-04 | 2011-12-28 | 山东中厦电子科技有限公司 | B value changeable negative temperature coefficient thermistor composition and method of producing the same |
| CN101618959B (en) * | 2009-07-28 | 2012-05-23 | 四川西汉电子科技有限责任公司 | Low-resistivity and high-B-value negative temperature coefficient thermosensitive material and preparation method thereof |
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| CN110542488A (en) * | 2019-09-23 | 2019-12-06 | 安徽晶格尔电子有限公司 | Method for high-temperature measurement by using thermistor substrate |
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| CN1348192A (en) * | 2000-10-11 | 2002-05-08 | 株式会社村田制作所 | Semiconductor ceramic with negative resistance temperature coefficient and negative temperature coefficient thermistor |
| CN1624821A (en) * | 2004-12-21 | 2005-06-08 | 上海维安热电材料股份有限公司 | NTC thermosensitive resistance element made of semiconductor ceramic |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5143591B2 (en) | 1972-07-04 | 1976-11-22 | ||
| CN1348192A (en) * | 2000-10-11 | 2002-05-08 | 株式会社村田制作所 | Semiconductor ceramic with negative resistance temperature coefficient and negative temperature coefficient thermistor |
| CN1624821A (en) * | 2004-12-21 | 2005-06-08 | 上海维安热电材料股份有限公司 | NTC thermosensitive resistance element made of semiconductor ceramic |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104495942A (en) * | 2014-12-31 | 2015-04-08 | 郑州大学 | Negative thermal expansion material NdMnO3 and preparation method thereof |
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