JPS6150362B2 - - Google Patents
Info
- Publication number
- JPS6150362B2 JPS6150362B2 JP13967480A JP13967480A JPS6150362B2 JP S6150362 B2 JPS6150362 B2 JP S6150362B2 JP 13967480 A JP13967480 A JP 13967480A JP 13967480 A JP13967480 A JP 13967480A JP S6150362 B2 JPS6150362 B2 JP S6150362B2
- Authority
- JP
- Japan
- Prior art keywords
- temperature
- nickel oxide
- thermistor
- thermistor element
- present
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 22
- 229910000480 nickel oxide Inorganic materials 0.000 claims description 14
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical group [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 claims description 14
- 239000004408 titanium dioxide Substances 0.000 claims description 11
- 238000005245 sintering Methods 0.000 claims description 3
- 239000000203 mixture Substances 0.000 description 9
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 238000001354 calcination Methods 0.000 description 2
- 229910017052 cobalt Inorganic materials 0.000 description 2
- 239000010941 cobalt Substances 0.000 description 2
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 239000010419 fine particle Substances 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- YDZQQRWRVYGNER-UHFFFAOYSA-N iron;titanium;trihydrate Chemical group O.O.O.[Ti].[Fe] YDZQQRWRVYGNER-UHFFFAOYSA-N 0.000 description 2
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 2
- 229910052697 platinum Inorganic materials 0.000 description 2
- 230000001681 protective effect Effects 0.000 description 2
- 229910000314 transition metal oxide Inorganic materials 0.000 description 2
- 235000016068 Berberis vulgaris Nutrition 0.000 description 1
- 241000335053 Beta vulgaris Species 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 238000009529 body temperature measurement Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- 238000005036 potential barrier Methods 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Landscapes
- Thermistors And Varistors (AREA)
Description
本発明は、温度測定および温度制御等に用いら
れる高温用サーミスタ素子に関する。
従来のサーミスタは、サーミスタ材料であるマ
ンガン、コバルト、ニツケル、銅、鉄等の遷移金
属酸化物を適当な組成で混合、成形、焼成してサ
ーミスタ素子としてきたが、一般に高温での抵抗
温度係数が小さく、サーミスタ素子として使用可
能な温度範囲は300℃以下に限られている。
そのため、従来のサーミスタ素子は自動車の排
気ガスを完全燃焼させるためのサーマルリアクタ
の温度検出や各種家庭電化製品の温度検出などの
300℃を越える高温域で使用することができなか
つた。現在、この高温用サーミスタ素子として、
いくつかの他の材料が知られているが、いずれも
高温での安定性および信頼性の点で問題が残され
ている。
発明者らは、このような問題点を解決するため
に、さまざまな視点から鋭意研究検討を加えた結
果、酸化ニツケルがそれ自体では成形性が悪く、
サーミスタ定数Ｂが小さく、また雰囲気に対する
安定性が悪い欠点がある反面、高温でのサーミス
タ特性が良好なＰ型半導体であることに着目し、
酸化ニツケルに対する第二成分の影響を多岐にわ
たつて詳細に検討した結果、本発明を完成するに
至つた。
本発明は、300℃以上の高温、特に500℃以上約
900℃の高温でも安定に動作し、信頼性の高いサ
ーミスタ素子を提供することを目的とする。
本発明は、主成分が酸化ニツケルであつて、こ
の酸化ニツケルに二酸化チタンが0.1〜50モル％
添加された組成の成形体を焼結してなることを特
徴とする。なお酸化ニツケルの純度は98％以上で
あることが好ましい。
すなわち本発明に係る高温用サーミスタ素子の
製造方法は、まず純度が98％以上の酸化ニツケル
に二酸化チタンを0.1〜50モル％添加する。この
二酸化チタンの組成比が50モル％を越えるとサー
ミスタ素子の抵抗値が高くなり実用に適さなくな
る。次にこの酸化ニツケルと二酸化チタンを比表
面積が1000cm2／ｇ以上、好ましくは5000cm2／ｇ以
上の微細な粒度の粒子になるまで粉砕し十分混合
する。このとき、バインダを入れることもでき
る。
次いでこれを好ましくは600〜800℃で、10分〜
３時間予備焼成した後、空気中で冷却し再び上記
粒度の粒子になるまで粉砕する。次いでこれをビ
ート状、デイスク状、円柱状、厚膜状等の所望の
形状に成形する。さらにこの成形体を1100〜1500
℃で、10分〜６時間本焼成した後、空気中で冷却
して本発明のサーミスタ素子が得られる。
このサーミスタ素子をサーミスタとして使用す
るには、さらに電極として白金、金、銀等の貴金
属材料を成形時あるいは成形後に付与することに
より完成する。本発明サーミスタ素子は高温用の
ため、とくに吸湿防止用の保護膜は不要である
が、使用の環境によつては、保護膜またはシール
等を施すことができる。
サーミスタ素子の形状および大きさについて
は、使用の条件を考慮して、焼成が可能な範囲で
原則的に制限はない。
酸化ニツケルの純度については、80％以上で本
発明の効果が見られ、98％以上で効果が顕著であ
る。このときに許容できる不純物はこれが微量で
あるときには特に問題とならないが、１モル％を
越える場合には、マンガン、コバルト、銅、鉄等
の遷移金属酸化物であることが好ましい。出発原
料中への不純物の存在は粒界に不純物偏析させ、
ポテンシヤルバリヤを形成するため問題となる。
本発明のサーミスタ素子についてＸ線回折によ
り分析を行つたところ、NiTiO3が生成している
ことが判明した。このNiTiO3の結晶構造はイル
メナイト構造である。
本発明の効果が得られる物理的理由について
は、なお十分に解明されていないが、ほぼ次のよ
うに推定される。
酸化ニツケルに二酸化チタンを添加すると焼結
体組織中にNiOとNiTiO3の二相が生成する。
NiTiO3は抵抗値が高く、高温でｎ型の伝導を示
し、NiOは比較的抵抗が低くｐ型伝導を示す。本
発明の焼結体はこれら二相が分散性よく分布する
ため、互いに粒接触を持ち、熱履歴が少なく高温
で温度係数が大きい素子が得られると考えられ
る。なお、この組成物は高温においても相転移は
起すことなく安定である。
次に本発明を実施例により詳しく説明する。
まず酸化ニツケルに二酸化チタンを次表に示さ
れる４種の組成比（モル％）に選んで添加し、比
表面積が5000cm2／ｇの微細な粒度の粒子になるま
で粉砕し十分混合する。次に800℃で１時間予備
焼成した後、空気中で３時間炉内で放冷し再び上
記粒度の粒子になるまで粉砕する。
次いで常温下2000Kg／cm2の圧力でプレス成形し
てから1300℃の温度で１時間、本焼成して厚さ４
mm、直径10mmのデイスク状焼結体にする。このデ
イスク状焼結体の両面に白金ペーストを焼付けて
電極とし、比抵抗の測定をした。
The present invention relates to a high temperature thermistor element used for temperature measurement, temperature control, etc. Conventional thermistors have been made by mixing transition metal oxides such as manganese, cobalt, nickel, copper, and iron, which are thermistor materials, in an appropriate composition, forming, and firing them to form a thermistor element, but generally the temperature coefficient of resistance at high temperatures is It is small and the temperature range in which it can be used as a thermistor element is limited to 300°C or less. Therefore, conventional thermistor elements are used to detect the temperature of thermal reactors for complete combustion of automobile exhaust gas and the temperature of various home appliances.
It could not be used in high temperature ranges exceeding 300℃. Currently, as this high temperature thermistor element,
Several other materials are known, but all remain problematic in terms of stability and reliability at high temperatures. In order to solve these problems, the inventors conducted intensive research and examination from various viewpoints, and found that nickel oxide itself has poor moldability.
Focusing on the fact that it is a P-type semiconductor with good thermistor characteristics at high temperatures, although it has the drawbacks of a small thermistor constant B and poor stability against the atmosphere,
As a result of extensive and detailed study of the influence of the second component on nickel oxide, the present invention was completed. The present invention is applicable to high temperatures of 300°C or higher, particularly 500°C or higher.
The aim is to provide a highly reliable thermistor element that operates stably even at high temperatures of 900℃. The main component of the present invention is nickel oxide, and titanium dioxide is contained in the nickel oxide in an amount of 0.1 to 50 mol%.
It is characterized by being formed by sintering a molded body having the added composition. Note that the purity of nickel oxide is preferably 98% or more. That is, in the method for manufacturing a high-temperature thermistor element according to the present invention, 0.1 to 50 mol% of titanium dioxide is first added to nickel oxide having a purity of 98% or more. If the composition ratio of titanium dioxide exceeds 50 mol %, the resistance value of the thermistor element becomes high, making it unsuitable for practical use. Next, the nickel oxide and titanium dioxide are ground and thoroughly mixed until they become fine particles with a specific surface area of 1000 cm 2 /g or more, preferably 5000 cm 2 /g or more. At this time, a binder can also be added. This is then preferably heated at 600 to 800°C for 10 minutes to
After preliminarily calcining for 3 hours, the mixture is cooled in air and pulverized again until the particles have the above-mentioned particle size. Next, this is formed into a desired shape such as a beet shape, a disk shape, a cylinder shape, or a thick film shape. Furthermore, this molded body is 1100~1500
℃ for 10 minutes to 6 hours, and then cooled in air to obtain the thermistor element of the present invention. In order to use this thermistor element as a thermistor, it is completed by further applying a noble metal material such as platinum, gold, silver, etc. as an electrode during or after molding. Since the thermistor element of the present invention is used at high temperatures, it does not require a protective film to prevent moisture absorption, but depending on the environment of use, a protective film or a seal can be applied. There are no restrictions in principle on the shape and size of the thermistor element, as long as it can be fired, taking into account the conditions of use. Regarding the purity of nickel oxide, the effect of the present invention is seen when it is 80% or more, and the effect is remarkable when it is 98% or more. When the impurity is in a trace amount, there is no particular problem, but when it exceeds 1 mol %, transition metal oxides such as manganese, cobalt, copper, and iron are preferable. The presence of impurities in the starting material causes impurity segregation at grain boundaries,
This poses a problem because it forms a potential barrier. When the thermistor element of the present invention was analyzed by X-ray diffraction, it was found that NiTiO 3 was generated. The crystal structure of this NiTiO 3 is an ilmenite structure. Although the physical reason for achieving the effects of the present invention has not yet been fully elucidated, it is estimated to be approximately as follows. When titanium dioxide is added to nickel oxide, two phases of NiO and NiTiO 3 are generated in the structure of the sintered body.
NiTiO 3 has a high resistance value and exhibits n-type conduction at high temperatures, while NiO has a relatively low resistance and exhibits p-type conduction. In the sintered body of the present invention, these two phases are distributed in a well-dispersed manner, so that they have grain contact with each other, and it is thought that an element having a small thermal history and a large temperature coefficient at high temperatures can be obtained. Note that this composition is stable even at high temperatures without causing a phase transition. Next, the present invention will be explained in detail with reference to examples. First, titanium dioxide is added to nickel oxide in four composition ratios (mol%) shown in the table below, and the mixture is ground and thoroughly mixed until it becomes fine particles with a specific surface area of 5000 cm 2 /g. Next, after preliminarily calcining at 800° C. for 1 hour, the mixture is left to cool in a furnace in air for 3 hours, and then pulverized again until it becomes particles of the above particle size. Next, it was press-formed at room temperature at a pressure of 2000 kg/cm 2 and then fired at a temperature of 1300°C for 1 hour to a thickness of 4.
mm, into a disc-shaped sintered body with a diameter of 10 mm. Platinum paste was baked on both sides of this disk-shaped sintered body to form electrodes, and the specific resistance was measured.
【表】
図は本発明実施例高温用サーミスタ素子のサー
ミスタ温度特性とＢ定数を示す図である。
図において、たて軸は比抵抗（単位Ωcm）、よ
こ軸は温度係数（単位K-1）を示し、図中の丸で
囲んだ数字は表の試料番号にそれぞれ対応してい
る。
二酸化チタンの添加量が増加するに従つて、試
料の比抵抗は大きくなり、同時に温度係数が大き
くなることがわかる。サーミスタ定数Ｂは、試料
１においてＢ＝5000〔〓〕、試料２においてＢ＝
7500〔〓〕、試料３においてＢ＝9500〔〓〕、試料
４においてＢ＝10500〔〓〕と十分大きくまた広
範囲にわたつている。
このため二酸化チタンの添加量を選ぶことによ
り、任意のサーミスタ定数Ｂを持つ素子を作るこ
とが可能となる。またこの反応にはヒステリシス
が見られず、安定した特性が示された。
以上述べたように、本発明によれば、酸化ニツ
ケルに二酸化チタンを0.1〜50モル％添加した組
成の成形体を焼結することにより、
(イ) NiOとイルメナイト構造をとるNiTiO3との
二相からなるため、500℃以上の高温で特に900
℃の高温度下においても温度に対する抵抗変化
が大きく、安定に動作し、使用可能である、
(ロ) 温度に対する抵抗変化の再現性の良い、
(ハ) 二酸化チタンの添加量を変化させることによ
りサーミスタ定数Ｂを広範囲にとることのでき
る、
(ニ) 湿度による影響を受けない、
(ホ) 高温における経時変化のない、
(ヘ) 材料の成形性のよい、
優れた効果がある。[Table] The figure is a diagram showing the thermistor temperature characteristics and B constant of the high temperature thermistor element according to the present invention. In the figure, the vertical axis shows the specific resistance (unit: Ωcm), the horizontal axis shows the temperature coefficient (unit: K -1 ), and the numbers in circles in the figure correspond to the sample numbers in the table, respectively. It can be seen that as the amount of titanium dioxide added increases, the specific resistance of the sample increases and at the same time the temperature coefficient increases. The thermistor constant B is B=5000 [〓] for sample 1, and B=5000 for sample 2.
7500 [〓], B = 9500 [〓] in sample 3, and B = 10500 [〓] in sample 4, which are sufficiently large and spread over a wide range. Therefore, by selecting the amount of titanium dioxide added, it is possible to produce an element having an arbitrary thermistor constant B. Moreover, no hysteresis was observed in this reaction, indicating stable characteristics. As described above, according to the present invention, by sintering a molded body having a composition of nickel oxide with 0.1 to 50 mol% of titanium dioxide added, (a) NiO and NiTiO 3 having an ilmenite structure are combined. 900°C, especially at high temperatures of 500°C or higher.
It has a large resistance change with temperature even at high temperatures of ℃, so it operates stably and can be used.(b) Good reproducibility of resistance change with temperature.(c) By changing the amount of titanium dioxide added. The thermistor constant B can be varied over a wide range, (d) it is not affected by humidity, (e) there is no change over time at high temperatures, and (f) the material has excellent formability.
図は本発明実施例高温用サーミスタ素子のサー
ミスタ温度特性とＢ定数を示す図。
The figure shows the thermistor temperature characteristics and B constant of the high-temperature thermistor element according to the embodiment of the present invention.
Claims (1)
ツケルに二酸化チタンが0.1〜50モル％添加され
た組成の成形体を焼結してなる高温用サーミスタ
素子。 ２ 酸化ニツケルの純度が98％以上であることを
特徴とする特許請求の範囲第１項記載の高温用サ
ーミスタ素子。[Scope of Claims] 1. A high-temperature thermistor element obtained by sintering a molded body whose main component is nickel oxide, with 0.1 to 50 mol% of titanium dioxide added to the nickel oxide. 2. The high temperature thermistor element according to claim 1, wherein the purity of the nickel oxide is 98% or more.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13967480A JPS5763801A (en) | 1980-10-06 | 1980-10-06 | High temperautre thermistor element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13967480A JPS5763801A (en) | 1980-10-06 | 1980-10-06 | High temperautre thermistor element |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5763801A JPS5763801A (en) | 1982-04-17 |
| JPS6150362B2 true JPS6150362B2 (en) | 1986-11-04 |
Family
ID=15250770
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13967480A Granted JPS5763801A (en) | 1980-10-06 | 1980-10-06 | High temperautre thermistor element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5763801A (en) |
-
1980
- 1980-10-06 JP JP13967480A patent/JPS5763801A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5763801A (en) | 1982-04-17 |
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